Tailored gamification: A review of literature

Gamification is increasingly becoming a pertinent aspect of any UI and UX design. However, a canonical dearth in research and application of gamification has been related to the role of individual differences in susceptibility to gamification and its varied designs. To address this gap, this study reviews the extant corpus of research on tailored gamification (42 studies). The findings of the review indicate that most studies on the field are mostly focused on user modeling for a future personalization, adaptation, or recommendation of game elements. This user model usually contains the users’ preferences of play (i.e., player types), and is mostly applied in educational settings. The main contributions of this paper are a standardized terminology of the game elements used in tailored gamification, the discussion on the most suitable game elements for each users’ characteristic, and a research agenda including dynamic modeling, exploring multiple characteristics simultaneously, and understanding the effects of other aspects of the interaction on user experience.

General information

Publication status: Published
MoE publication type: A2 Review article in a scientific journal
Organisations: Computing Sciences, Tampere University, Federal University of Rio Grande do Sul, State University of Santa Catarina
Contributors: Klock, A. C. T., Gasparini, I., Pimenta, M. S., Hamari, J.
Publication date: 1 Dec 2020
Peer-reviewed: Yes

Publication information

Journal: International Journal of Human Computer Studies
Volume: 144
Article number: 102495
ISSN (Print): 1071-5819
Original language: English
ASJC Scopus subject areas: Software, Human Factors and Ergonomics, Education, Engineering(all), Human-Computer Interaction, Hardware and Architecture
Keywords: Adaptation, Gamification, Personalization, Recommendation, Systematic review, Tailoring
Electronic versions: 
Source: Scopus
Source ID: 85086582163

Research output: Contribution to journalReview ArticleScientificpeer-review

The effect of challenge-based gamification on learning: An experiment in the context of statistics education

Gamification is increasingly employed in learning environments as a way to increase student motivation and consequent learning outcomes. However, while the research on the effectiveness of gamification in the context of education has been growing, there are blind spots regarding which types of gamification may be suitable for different educational contexts. This study investigates the effects of the challenge-based gamification on learning in the area of statistics education. We developed a gamification approach, called Horses for Courses, which is composed of main game design patterns related to the challenge-based gamification; points, levels, challenges and a leaderboard. Having conducted a 2 (read: yes vs. no) x 2 (gamification: yes vs. no) between-subject experiment, we present a quantitative analysis of the performance of 365 students from two different academic majors: Electrical and Computer Engineering (n=279), and Business Administration (n=86). The results of our experiments show that the challenge-based gamification had a positive impact on student learning compared to traditional teaching methods (compared to having no treatment and treatment involving reading exercises). The effect was larger for females or for students at the School of Electrical and Computer Engineering.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, National Technical University of Athens, Tampere University, Gamification Group
Contributors: Legaki, N. Z., Xi, N., Hamari, J., Karpouzis, K., Assimakopoulos, V.
Publication date: 1 Dec 2020
Peer-reviewed: Yes

Publication information

Journal: International Journal of Human Computer Studies
Volume: 144
Article number: 102496
ISSN (Print): 1071-5819
Original language: English
ASJC Scopus subject areas: Software, Human Factors and Ergonomics, Education, Engineering(all), Human-Computer Interaction, Hardware and Architecture
Keywords: Applications in education, Gamification, Human-Computer interface, Statistics education, Teaching forecasting
Electronic versions: 
Source: Scopus
Source ID: 85086641706

Research output: Contribution to journalArticleScientificpeer-review

Some SonarQube issues have a significant but small effect on faults and changes. A large-scale empirical study

Context: Companies frequently invest effort to remove technical issues believed to impact software qualities, such as removing anti-patterns or coding styles violations. Objective: We aim to analyze the diffuseness of SonarQube issues in software systems and to assess their impact on code changes and fault-proneness, considering also their different types and severities. Methods: We conducted a case study among 33 Java projects from the Apache Software Foundation repository. Results: We analyzed 726 commits containing 27K faults and 12M changes in Java files. The projects violated 173 SonarQube rules generating more than 95K SonarQube issues in more than 200K classes. Classes not affected by SonarQube issues are less change-prone than affected ones, but the difference between the groups is small. Non-affected classes are slightly more change-prone than classes affected by SonarQube issues of type Code Smell or Security Vulnerability. As for fault-proneness, there is no difference between non-affected and affected classes. Moreover, we found incongruities in the type and severity assigned by SonarQube. Conclusion: Our result can be useful for practitioners to understand which SonarQube issues should be refactored and for researchers to bridge the missing gaps. Moreover, results can also support companies and tool vendors in identifying SonarQube issues as accurately as possible.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, LUT University
Contributors: Lenarduzzi, V., Saarimäki, N., Taibi, D.
Number of pages: 15
Publication date: Dec 2020
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 170
Article number: 110750
ISSN (Print): 0164-1212
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture
Keywords: Change-proneness, Empirical study, Fault-proneness, SonarQube

Bibliographical note

EXT="Lenarduzzi, Valentina"

Source: Scopus
Source ID: 85087390369

Research output: Contribution to journalArticleScientificpeer-review

Necessary and sufficient conditions for the existence of solution of generalized fuzzy relation equations A ⇔X = B

In 2013 Li and Jin studied a particular type of fuzzy relational equations on finite sets, where the introduced min-bi-implication composition is based on Łukasiewicz equivalence. In this paper such fuzzy relation equations are studied on a more general level, namely complete residuated lattice valued fuzzy relation equations of type ⋀y∈Y(A(x,y)↔X(y)=B(x) are analyzed, and the existence of solutions S is studied. First a necessary condition for the existence of solution is established, then conditions for lower and upper limits of solutions are given, and finally sufficient conditions for the existence of the smallest and largest solutions, respectively, are characterized. If such general or global solutions do not exist, there might still be partial or point wise solutions; this is a novel way to study fuzzy relation equations. Such point wise solutions are studied on Łukasiewicz, Product and Gödel t-norm based residuated lattices on the real unit interval.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Computer Science and Applied Logics
Contributors: Turunen, E.
Number of pages: 7
Pages: 351-357
Publication date: 1 Oct 2020
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 536
ISSN (Print): 0020-0255
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Fuzzy relation equation, Residuated lattice, T-norm
URLs: 
Source: Scopus
Source ID: 85085840362

Research output: Contribution to journalArticleScientificpeer-review

Using Deep Learning for price prediction by exploiting stationary limit order book features

The recent surge in Deep Learning (DL) research of the past decade has successfully provided solution to many difficult problems. The field of Quantitative analysis has been slowly adapting the new methods to its problems, but due to problems such as the non-stationary nature of financial data, significant challenges must be overcome before DL is fully utilized. In this work a new method to construct stationary features is proposed such that allows DL models to be applied effectively. These features are thoroughly tested on the task of predicting mid price movements of the Limit Order Book. Several DL models are evaluated such as recurrent Long Short Term Memory (LSTM) networks and Convolutional Neural Networks (CNN). Finally a novel model that combines the ability of the CNN to extract useful features and the ability of LSTMs’ to analyse time series, is proposed and evaluated. The combined model is able to outperform the individual LSTM and CNN models in the prediction horizons that are tested.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Aristotle University of Thessaloniki, University of Milan Bicocca, Department of Informatics, Aarhus Universitet
Contributors: Tsantekidis, A., Passalis, N., Tefas, A., Kanniainen, J., Gabbouj, M., Iosifidis, A.
Publication date: 1 Aug 2020
Peer-reviewed: Yes

Publication information

Journal: Applied Soft Computing Journal
Volume: 93
Article number: 106401
ISSN (Print): 1568-4946
Original language: English
ASJC Scopus subject areas: Software
Keywords: Deep Learning, Limit order book, Price forecasting, Stationary features

Bibliographical note

EXT="Tefas, Anastasios"
EXT="Iosifidis, Alexandros"

Source: Scopus
Source ID: 85084845392

Research output: Contribution to journalArticleScientificpeer-review

Flow-bounded trajectory-scaling algorithm for hydraulic robotic manipulators

On-line methods for trajectory scaling have focused on torque or acceleration bounded minimum time trajectories, while other system constraints have received little attention. For hydraulic systems, volumetric flow rate of the supply unit establishes a critical constraint, that has been neglected in control design. Consequently, commercial solutions for robotic control of hydraulic manipulators are typically limited to a compromise of a slower constant endpoint velocity, that can be achieved in any operating point without violating the constrained flow rate. However, with real-time analysis of the required volumetric flow rate, the desired trajectories can be executed much faster without violating the flow rate constraint or losing control accuracy. This study proposes an on-line method for trajectory scaling to perform predetermined trajectories in minimum time. Essentially, the method scales velocity along the trajectory to maintain achievable velocity at all times. The proposed method is capable of enforcing a global volumetric flow limit, whether it is constant or time-varying. The method is validated with simulations and experiments with a real hydraulic robotic manipulator. Experimental results show a very significant improvement in the trajectory tracking control, where the tracking error is reduced from 461 mm to 73 mm on a square trajectory.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation Technology and Mechanical Engineering, Rambooms Oy
Contributors: Lampinen, S., Niemi, J., Mattila, J.
Number of pages: 6
Pages: 619-624
Publication date: 1 Jul 2020

Host publication information

Title of host publication: 2020 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2020
Publisher: IEEE
ISBN (Electronic): 9781728167947

Publication series

Name: IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM
ISSN (Electronic): 2159-6255
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Computer Science Applications, Software
Electronic versions: 

Bibliographical note

jufoid=73592

Source: Scopus
Source ID: 85090380825

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

On the zeros of the partial Hosoya polynomial of graphs

The partial Hosoya polynomial (or briefly the partial H-polynomial) can be used to construct the well-known Hosoya polynomial. The ith coefficient of this polynomial, defined for an arbitrary vertex u of a graph G, is the number of vertices at distance i from u. The aim of this paper is to determine the partial H-polynomial of several well-known graphs and, then, to investigate the location of their zeros. To pursue, we characterize the structure of graphs with the minimum and the maximum modulus of the zeros of partial H-polynomial. Finally, we define another graph polynomial of the partial H-polynomial, see [9]. Also, we determine the unique positive root of this polynomial for particular graphs.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Shahid Rajaee Teacher Training University, Swiss Distance University of Applied Sciences, Institute for Bioinformatics and Translational Research, Nankai University, Tianjin Polytechnic University, Central South University China, Aalto University, Peking University, Mathematics Faculty of Information Technology and Communication Sciences
Contributors: Ghorbani, M., Dehmer, M., Cao, S., Feng, L., Tao, J., Emmert-Streib, F.
Number of pages: 17
Pages: 199-215
Publication date: 1 Jul 2020
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 524
ISSN (Print): 0020-0255
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Cut-vertex, Distance, Hosoya polynomial, Polynomial roots
Source: Scopus
Source ID: 85083078026

Research output: Contribution to journalArticleScientificpeer-review

Kvazaar 2.0: Fast and efficient open-source HEVC inter encoder

High Efficiency Video Coding (HEVC) is the key to economic video transmission and storage in the current multimedia applications but tackling its inherent computational complexity requires powerful video codec implementations. This paper presents Kvazaar 2.0 HEVC encoder that is the new release of our academic open-source software (github.com/ultravideo/kvazaar). Kvazaar 2.0 introduces novel inter coding functionality that is built on advanced rate-distortion optimization (RDO) scheme and speeded up with several early termination mechanisms, SIMD-optimized coding tools, and parallelization strategies. Our experimental results show that the proposed coding scheme makes Kvazaar 125 times as fast as the HEVC reference software HM on the Intel Xeon E5-2699 v4 22-core processor at the additional coding cost of only 2.4% on average. In constant quantization parameter (QP) coding, Kvazaar is also 3 times as fast as the respective preset of the well-known practical x265 HEVC encoder and is still able to attain 10.7% lower average bit rate than x265 for the same objective visual quality. These results indicate that Kvazaar has become one of the leading open-source HEVC encoders in practical high-efficiency video coding.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research area: Computer engineering
Contributors: Lemmetti, A., Viitanen, M., Mercat, A., Vanne, J.
Number of pages: 6
Pages: 237-242
Publication date: 27 May 2020

Host publication information

Title of host publication: MMSys 2020 - Proceedings of the 2020 Multimedia Systems Conference
Publisher: ACM
ISBN (Electronic): 9781450368452
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Human-Computer Interaction, Software
Keywords: high efficiency video coding (HEVC), inter coding, Kvazaar HEVC encoder, open-source, rate-distortion optimization (RDO)
Source: Scopus
Source ID: 85086766655

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Adaptive Normalization for Forecasting Limit Order Book Data Using Convolutional Neural Networks

Deep learning models are capable of achieving state-of-the-art performance on a wide range of time series analysis tasks. However, their performance crucially depends on the employed normalization scheme, while they are usually unable to efficiently handle non-stationary features without first appropriately pre-processing them. These limitations impact the performance of deep learning models, especially when used for forecasting financial time series, due to their non-stationary and multimodal nature. In this paper we propose a data-driven adaptive normalization layer which is capable of learning the most appropriate normalization scheme that should be applied on the data. To this end, the proposed method first identifies the distribution from which the data were generated and then it dynamically shifts and scales them in order to facilitate the task at hand. The proposed nor-malization scheme is fully differentiable and it is trained in an end-to-end fashion along with the rest of the parameters of the model. The proposed method leads to significant performance improvements over several competitive normalization approaches, as demonstrated using a large-scale limit order book dataset.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research group: Multimedia Research Group - MRG, Aristotle University of Thessaloniki, Aarhus Universitet
Contributors: Passalis, N., Tefas, A., Kanniainen, J., Gabbouj, M., Iosifidis, A.
Number of pages: 5
Pages: 1713-1717
Publication date: 1 May 2020

Host publication information

Title of host publication: 2020 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2020 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781509066315

Publication series

Name: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Volume: 2020-May
ISSN (Print): 1520-6149
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering

Bibliographical note

EXT="Tefas, Anastasios"
EXT="Iosifidis, Alexandros"

Source: Scopus
Source ID: 85089240342

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Peer to Peer Offloading with Delayed Feedback: An Adversary Bandit Approach

Fog computing brings computation and services to the edge of networks enabling real time applications. In order to provide satisfactory quality of experience, the latency of fog networks needs to be minimized. In this paper, we consider a peer computation offloading problem for a fog network with unknown dynamics. Peer competition occurs when different fog nodes offload tasks to the same peer FN. In this paper, the computation offloading problem is modeled as a sequential FN selection problem with delayed feedback. We construct an online learning policy based on the adversary multi-arm bandit framework to deal with peer competition and delayed feedback. Simulation results validate the effectiveness of the proposed policy.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Electrical Engineering, Research group: Wireless Communications and Positioning, Shanghai Advanced Research Institute, Chinese Academy of Sciences, ShanghaiTech University, Shanghai Institute of Microsystem and Information Technology Chinese Academy of Sciences, Peoples’ Friendship University of Russia
Contributors: Yang, M., Zhu, H., Wang, H., Koucheryavy, Y., Samouylov, K., Qian, H.
Number of pages: 5
Pages: 5035-5039
Publication date: 1 May 2020

Host publication information

Title of host publication: 2020 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2020 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781509066315

Publication series

Name: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Volume: 2020-May
ISSN (Print): 1520-6149
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: adversary multi-arm bandit, delayed feed-back, Fog computing, reinforcement learning, task offloading
Source: Scopus
Source ID: 85089215773

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

SeCon-NG: Implementing a lightweight cryptographic library based on ECDH and ECDSA for the development of secure and privacy-preserving protocols in contiki-NG

There is no doubt that the Internet of Things (IoT) has the power to change our world and drive us to a complete social evolution. In business and industry, there are thousands of IoT use cases and real-life IoT deployments across a variety of sectors (e.g. industry 4.0 and smart factories, smart cities, etc.). However, due to the vastly resource constrained nature of the devices used in IoT, implementing secure and privacy-preserving services, using for example standard asymmetric cryptographic algorithms, has been a real challenge. The majority of IoT devices on the market currently employ the use of various forms of symmetric cryptography such as key pre-distribution. The overall efficiency of such implementations correlate directly to the size of the IoT environment and the deployment method. In this paper, we implement a lightweight cryptographic library that can be used to secure communication protocols between multiple communicating nodes without the need for external trusted entities or a server. Our implementation is based on modifying the Elliptic-Curve Diffie-Hillman (ECDH) and Elliptic Curve Digital Signature Algorithm (ECDSA) components of the Tinycrypt cryptographic library. This work focuses on extending the functionalities of the User Datagram Protocol (UDP) broadcast application on the Contiki-NG Operating System (OS) platform.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Frimpong, E., Michalas, A.
Number of pages: 3
Pages: 767-769
Publication date: 30 Mar 2020

Host publication information

Title of host publication: 35th Annual ACM Symposium on Applied Computing, SAC 2020
Publisher: ACM
ISBN (Electronic): 9781450368667
ASJC Scopus subject areas: Software
Keywords: Contiki-NG, Elliptic curve cryptography, Key distribution, Lightweight cryptography, Privacy, Wireless sensor networks
Source: Scopus
Source ID: 85083040552

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Gaussian mixture models for signal mapping and positioning

Maps of RSS from a wireless transmitter can be used for positioning or for planning wireless infrastructure. The RSS values measured at a single point are not always the same, but follow some distribution, which vary from point to point. In existing approaches in the literature this variation is neglected or its mapping requires making many measurements at every point, which makes the measurement collection very laborious. We propose to use GMs for modeling joint distributions of the position and the RSS value. The proposed model is more versatile than methods found in the literature as it models the joint distribution of RSS measurements and the location space. This allows us to model the distributions of RSS values in every point of space without making many measurement in every point. In addition, GMs allow us to compute conditional probabilities and posteriors of position in closed form. The proposed models can model any RSS attenuation pattern, which is useful for positioning in multifloor buildings. Our tests with WLAN signals show that positioning with the proposed algorithm provides accurate position estimates. We conclude that the proposed algorithm can provide useful information about distributions of RSS values for different applications.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Automation and Systems Theory, Aalto University, University of Liverpool, Universidad Antonio de Nebrija, Uppsala University
Contributors: Raitoharju, M., García-Fernández, F., Hostettler, R., Piché, R., Särkkä, S.
Publication date: 1 Mar 2020
Peer-reviewed: Yes
Early online date: 10 Oct 2019

Publication information

Journal: Signal Processing
Volume: 168
Article number: 107330
ISSN (Print): 0165-1684
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Software, Signal Processing, Computer Vision and Pattern Recognition, Electrical and Electronic Engineering
Keywords: Gaussian mixtures, Indoor positioning, RSS, Signal mapping, Statistical modeling
URLs: 
Source: Scopus
Source ID: 85073693932

Research output: Contribution to journalArticleScientificpeer-review

Serverless: What it Is, What to Do and What Not to Do

Serverless, the new buzzword, has been gaining a lot of attention from the developers and industry. Cloud vendors such as AWS and Microsoft have hyped the architecture almost everywhere, from practitioners' conferences to local events, to blog posts. In this work, we introduce serverless functions (also known as Function-as-a-Service or FaaS), together with on bad practices experienced by practitioners, members of the Tampere Serverless Meetup group.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Gofore Plc
Contributors: Nupponen, J., Taibi, D.
Number of pages: 2
Pages: 49-50
Publication date: 1 Mar 2020

Host publication information

Title of host publication: 2020 IEEE International Conference on Software Architecture Companion, ICSA-C 2020
Publisher: IEEE
ISBN (Electronic): 9781728174150
ASJC Scopus subject areas: Computer Science Applications, Hardware and Architecture, Software, Information Systems and Management
Keywords: FaaS, Function-as-a-service, Serverless
Source: Scopus
Source ID: 85085749334

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A custom processor for protocol-independent packet parsing

Networking devices such as switches and routers have traditionally had fixed functionality. They have the logic for the union of network protocols matching the application and market segment for which they have been designed. Possibility of adding new functionality is limited. One of the aims of Software Defined Networking is to make packet processing devices programmable. This provides for innovation and rapid deployment of novel networking protocols. The first step in processing of packets is packet parsing. In this paper, we present a custom processor for packet parsing. The parser is protocol-independent and can be programmed to parse any sequence of headers. It does so without the use of a Ternary Content Addressable Memory. As a result, the area and power consumption are noticeably smaller than in the state of the art. Moreover, its output is the same as that of the parser used in the Reconfigurable Match Tables (RMT). With an area no more than that of parsers in the RMT architecture, it sustains aggregate throughput of 3.4 Tbps in the worst case which is an improvement by a factor of 5.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research area: Computer engineering, University of Bologna
Contributors: Zolfaghari, H., Rossi, D., Nurmi, J.
Number of pages: 11
Publication date: 1 Feb 2020
Peer-reviewed: Yes
Early online date: 2019

Publication information

Journal: Microprocessors and Microsystems
Volume: 72
ISSN (Print): 0141-9331
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications, Artificial Intelligence
Keywords: Advanced program control, Packet parsing, Programmable data plane, Software defined networking
Source: Scopus
Source ID: 85074246120

Research output: Contribution to journalArticleScientificpeer-review

Are SonarQube Rules Inducing Bugs?

The popularity of tools for analyzing Technical Debt, and particularly the popularity of SonarQube, is increasing rapidly. SonarQube proposes a set of coding rules, which represent something wrong in the code that will soon be reflected in a fault or will increase maintenance effort. However, our local companies were not confident in the usefulness of the rules proposed by SonarQube and contracted us to investigate the fault-proneness of these rules. In this work we aim at understanding which SonarQube rules are actually fault-prone and to understand which machine learning models can be adopted to accurately identify fault-prone rules. We designed and conducted an empirical study on 21 well-known mature open-source projects. We applied the SZZ algorithm to label the fault-inducing commits. We analyzed the fault-proneness by comparing the classification power of seven machine learning models. Among the 202 rules defined for Java by SonarQube, only 25 can be considered to have relatively low fault-proneness. Moreover, violations considered as 'bugs' by SonarQube were generally not fault-prone and, consequently, the fault-prediction power of the model proposed by SonarQube is extremely low. The rules applied by SonarQube for calculating technical debt should be thoroughly investigated and their harmfulness needs to be further confirmed. Therefore, companies should carefully consider which rules they really need to apply, especially if their goal is to reduce fault-proneness.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Lappeenranta University of Technology
Contributors: Lenarduzzi, V., Lomio, F., Huttunen, H., Taibi, D.
Number of pages: 11
Pages: 501-511
Publication date: 1 Feb 2020

Host publication information

Title of host publication: SANER 2020 - Proceedings of the 2020 IEEE 27th International Conference on Software Analysis, Evolution, and Reengineering
Publisher: IEEE
Editors: Kontogiannis, K., Khomh, F., Chatzigeorgiou, A., Fokaefs, M., Zhou, M.
ISBN (Electronic): 9781728151434
ASJC Scopus subject areas: Organizational Behavior and Human Resource Management, Hardware and Architecture, Software, Safety, Risk, Reliability and Quality, Computer Networks and Communications
Keywords: architectural smells, code smells, coding style, machine learning, SonarQube, static analysis, Technical Debt

Bibliographical note

EXT="Lenarduzzi, Valentina"

Source: Scopus
Source ID: 85083565109

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A preliminary network analysis on steam game tags: Another way of understanding game genres

Video game genre classification has long been a focusing perspective in game studies domain. Despite the commonly acknowledged usefulness of genre classification, scholars in the game studies domain are yet to reach consensus on the game genre classification. On the other hand, Steam, a popular video game distribution platform, adopts the user-generated tag feature enabling players to describe and annotate video games based on their own understanding of genres. Despite the concern of the quality, the user-generated tags (game tags) provide an opportunity towards an alternative way of understanding video game genres based on the players' collective intelligence. Hence, in this study, we construct a network of game tags based on the co-occurrence of tags in games on Steam platform and analyze the structure of the network via centrality analysis and community detection. Such analysis shall provide an intuitive presentation on the distribution and connections of the game tags, which furthermore suggests a potential way of understanding the important tags that are commonly adopted and the main genres of video games.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Communication Sciences
Contributors: Li, X., Zhang, B.
Number of pages: 9
Pages: 65-73
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 29-30, 2020, Tampere, Finland
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: centrality, community detection, game tag, genre, modularity, network, steam, video game

Bibliographical note

INT=coms,"Li, Xiaozhou"

Source: Scopus
Source ID: 85080924784

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Color game: A collaborative social robotic game for icebreaking; Towards the design of robotic ambiences as part of smart building services

Social robots are entering our workplaces, homes, medical and educational systems in assistive and collaborative roles. In our research, we have investigated the use of a social robot Pepper as an interactive icebreaker host to create a positive atmosphere at events. This paper presents two user studies (total n=43) in which we evaluated two interactive prototypes of playful applications on Pepper, with the overall aim of providing a personal and entertaining service for event attendees. Data about users' experiences and attitudes were collected with semi-structured interviews, surveys, and observations. The results of the studies suggest that the majority of the participants had pleasurable and positive experiences with the robot and its applications. Moreover, their positive encounters led them to accept social robots as icebreaker hosts to connect with strangers. Based on our findings, we present a list of design implications to help the future design of social robots used to facilitate social connectedness, and to aid in the development of social robots as intelligent agents performing tasks as integrated parts of smart spaces.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Civil Engineering, Research group: Digitalization in the real estate and construction sector
Contributors: Beheshtian, N., Kaipainen, K., Kähkönen, K., Ahtinen, A.
Number of pages: 10
Pages: 10-19
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: human robot interaction, ice breaking, smart building, social connectedness, social robots, user experience
Source: Scopus
Source ID: 85080911326

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Demographic differences in accumulated types of capital in massively multiplayer online role-playing games

This paper examines how the demographic attributes and extra-game habits of players of a Massively Multiplayer Online Role-Playing Game (MMORPG) predict the accumulated capital of their avatars. An online survey (N=905) was conducted amidst the players of Final Fantasy XIV (FFXIV). Four types of capital were measured to map out the concrete and intangible resources of the avatars; social, economic, cultural and symbolic. The results show that weekly time spent playing the game is the strongest predictor of avatar capital and was associated with all types of capital. Time subscribed to the game was associated with cultural, economic, symbolic and bonding social capital. Social capital was found to be highest amongst both young and female players. Forum activity was associated with symbolic capital.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Communication Sciences, Research group: TUT Game Lab, Computing Sciences, Turun yliopisto
Contributors: Korkeila, H., Koivisto, J., Hamari, J.
Number of pages: 9
Pages: 74-82
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: avatar, capital, demographics, MMORPG
Source: Scopus
Source ID: 85080910780

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Innovation challenges as a novel multidisciplinary learning platform

Innovation Challenges is a new course offered for the whole Tampere university community by Y-kampus entrepreneurship and innovation services, for the first time in fall 2019. Innovation Challenges offers practice-based cases that allow students to develop their creativity and problem-solving skills in a team. Learning is anchored in team coaching pedagogy, learning-by-doing attitude and entrepreneurial mindset. In this paper, we first describe the evolution that created a course called Innovation Challenges. Then, we describe course organization and the six challenges that student teams are currently solving.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Information and Knowledge Management, Research group: Business Data Research Group, Tampere Uni. of Applied Sci., Tampere University
Contributors: Jokiniemi, S., Myllärniemi, J., Poranen, T., Vuorenmaa, M.
Number of pages: 4
Pages: 145-148
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: innovation, learning platform, multidisciplinary projects

Bibliographical note

INT=comp,"Poranen, Timo"

Source: Scopus
Source ID: 85080863203

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Satisfaction and willingness to consume immersive journalism: Experiment of differences between VR, 360 video, and article

Immersive journalism has been touted to revolutionize journalism due to its ability to afford a multi-modal engrossing experience. However, hardly any experiments have been conducted whether consumers' satisfaction and consequent intentions to use immersive journalistic media may differ from traditional forms of journalistic content. Therefore, in this study, we investigate the differences in satisfaction and continued use intentions between article, 360 video and VR-based interaction with content. The data was collected via a randomized controlled laboratory experiment with between-subjects design (N = 87). Participants were randomly assigned to reading a written article based on the video (article) and watching the video on a computer screen (2D 360) or in mobile VR (VR 360). The collected data consisted of demographics (age and gender) and reported satisfaction and intention to continue use. Results suggest that those who were assigned to VR 360 had higher intentions to continue use, but not greater satisfaction than those in the other two conditions. However, the intention was predicted to an extent by satisfaction as suggested by previous literature. Finally, age and gender did not predict continued use. These findings imply that users prefer the new media technology for consuming journalism content and support previous findings of the relationship between satisfaction and intention to continue use. Finally, avenues for further research are presented.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research group: TUT Game Lab
Contributors: Bujic, M., Hamari, J.
Number of pages: 6
Pages: 120-125
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: 360-degree video, age, gender, immersive journalism, intention to continue use, satisfaction, virtual reality
Source: Scopus
Source ID: 85080895604

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Social human-robot interaction in the wild: A workshop proposal for academic mindtrek 2020

This workshop will collect experts and stakeholders from all fields of human-robot interaction: both social and industrial applications and uses of robotics are of interest as far as they have human in the loop. The workshop will present recent and fully new research work in social HRI, including first results of a 3.5 month field trial and mixed-method study of a social robot Pepper in a shopping mall in Finland.

General information

Publication status: Published
MoE publication type: B3 Non-refereed article in conference proceedings
Organisations: Computing Sciences, Tampere University, VTT Technical Research Centre of Finland
Contributors: Niemelä, M., Ahtinen, A., Turunen, M.
Number of pages: 2
Pages: 168-169
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: collaborative robots, human-robot interaction, social robots

Bibliographical note

INT=comp,"Turunen, Markku"

Source: Scopus
Source ID: 85080870105

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientific

"The superhero of the university": Experience-driven design and field study of the university guidance robot

Robots have recently gained popularity in customer service. Especially social robots are nowadays utilized in healthcare, elderly homes and schools. Although it is crucial to design social robots according to well-defined user experience goals, research related to experience-driven design of social robots is still scarce. Experience-Driven Design (EDD) is a framework to design interaction for technology based on certain goals, known as experience goals. In this paper, we present the design and evaluation of the university guidance robot based on the user experience goals defined in previous research. The experience goals are nurture, fellowship and recreation. We designed applications, interaction, and robot's behavior to support the fulfillment of the experience goals. The social robot Pepper served as a platform for the university guidance robot. The evaluation was conducted as a field study in a university campus with 32 university students during the orientation week. According to our findings, the university guide robot successfully evoked nurture, fellowship and recreation among participants.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Chowdhury, A., Ahtinen, A., Kaipainen, K.
Number of pages: 9
Pages: 1-9
Publication date: 29 Jan 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: experience-driven design, social robots, user experience
Source: Scopus
Source ID: 85080943314

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Anthropometric clothing measurements from 3D body scans

We propose a full processing pipeline to acquire anthropometric measurements from 3D measurements. The first stage of our pipeline is a commercial point cloud scanner. In the second stage, a pre-defined body model is fitted to the captured point cloud. We have generated one male and one female model from the SMPL library. The fitting process is based on non-rigid iterative closest point algorithm that minimizes overall energy of point distance and local stiffness energy terms. In the third stage, we measure multiple circumference paths on the fitted model surface and use a nonlinear regressor to provide the final estimates of anthropometric measurements. We scanned 194 male and 181 female subjects, and the proposed pipeline provides mean absolute errors from 2.5 to 16.0 mm depending on the anthropometric measurement.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Vision, NOMO Technologies Ltd
Contributors: Yan, S., Wirta, J., Kämäräinen, J.
Number of pages: 11
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Machine Vision and Applications
Volume: 31
Issue number: 1-2
Article number: 7
ISSN (Print): 0932-8092
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Vision and Pattern Recognition, Computer Science Applications
Keywords: 3D body model, Anthropometric measurement, Non-rigid ICP
Source: Scopus
Source ID: 85078296322

Research output: Contribution to journalArticleScientificpeer-review

Censor-Based Cooperative Multi-Antenna Spectrum Sensing with Imperfect Reporting Channels

The present contribution proposes a spectrally efficient censor-based cooperative spectrum sensing (C-CSS) approach in a sustainable cognitive radio network that consists of multiple antenna nodes and experiences imperfect sensing and reporting channels. In this context, exact analytic expressions are first derived for the corresponding probability of detection, probability of false alarm, and secondary throughput, assuming that each secondary user (SU) sends its detection outcome to a fusion center only when it has detected a primary signal. Capitalizing on the findings of the analysis, the effects of critical measures, such as the detection threshold, the number of SUs, and the number of employed antennas, on the overall system performance are also quantified. In addition, the optimal detection threshold for each antenna based on the Neyman-Pearson criterion is derived and useful insights are developed on how to maximize the system throughput with a reduced number of SUs. It is shown that the C-CSS approach provides two distinct benefits compared with the conventional sensing approach, i.e., without censoring: i) the sensing tail problem, which exists in imperfect sensing environments, can be mitigated; and ii) less SUs are ultimately required to obtain higher secondary throughput, rendering the system more sustainable.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: Wireless Communications and Positioning, Electrical Engineering, Taiyuan University of Science and Technology, University of Waterloo, Khalifa University, University of Surrey, University of London, Simon Fraser University
Contributors: Li, M., Alhussein, O., Sofotasios, P. C., Muhaidat, S., Yoo, P. D., Liang, J., Wang, A.
Number of pages: 13
Pages: 48-60
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Sustainable Computing
Volume: 5
Issue number: 1
ISSN (Print): 2377-3782
Original language: English
ASJC Scopus subject areas: Computational Theory and Mathematics, Hardware and Architecture, Software, Renewable Energy, Sustainability and the Environment, Control and Optimization
Keywords: censoring, cooperative spectrum sensing, energy detection, energy efficiency, imperfect reporting channels, multi-antenna systems, Sustainble computing
Source: Scopus
Source ID: 85081759371

Research output: Contribution to journalArticleScientificpeer-review

Compressive sensed video recovery via iterative thresholding with random transforms

The authors consider the problem of compressive sensed video recovery via iterative thresholding algorithm. Traditionally, it is assumed that some fixed sparsifying transform is applied at each iteration of the algorithm. In order to improve the recovery performance, at each iteration the thresholding could be applied for different transforms in order to obtain several estimates for each pixel. Then the resulting pixel value is computed based on obtained estimates using simple averaging. However, calculation of the estimates leads to significant increase in reconstruction complexity. Therefore, the authors propose a heuristic approach, where at each iteration only one transform is randomly selected from some set of transforms. First, they present simple examples, when block-based 2D discrete cosine transform is used as the sparsifying transform, and show that the random selection of the block size at each iteration significantly outperforms the case when fixed block size is used. Second, building on these simple examples, they apply the proposed approach when video block-matching and 3D filtering (VBM3D) is used for the thresholding and show that the random transform selection within VBM3D allows to improve the recovery performance as compared with the recovery based on VBM3D with fixed transform.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Computational Imaging-CI, ITMO University, Linköping University, University of Oulu
Contributors: Belyaev, E., Codreanu, M., Juntti, M., Egiazarian, K.
Number of pages: 14
Pages: 1187-1200
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: IET Image Processing
Volume: 14
Issue number: 6
ISSN (Print): 1751-9659
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Electrical and Electronic Engineering

Bibliographical note

EXT="Belyaev, Evgeny"

Source: Scopus
Source ID: 85084175769

Research output: Contribution to journalArticleScientificpeer-review

Does code quality affect pull request acceptance? An empirical study

Background: Pull requests are a common practice for making contributions and reviewing them in both open-source and industrial contexts.

Objective: Our goal is to understand whether quality flaws such as code smells, anti-patterns, security vulnerabilities, and coding style violations in a pull request's code affect the chance of its acceptance when reviewed by a maintainer of the project.

Method: We conducted a case study among 28 Java open-source projects, analyzing the presence of 4.7 M code quality flaws in 36 K pull requests. We analyzed further correlations by applying logistic regression and six machine learning techniques. Moreover, we manually validated 10% of the pull requests to get further qualitative insights on the importance of quality issues in cases of acceptance and rejection.

Results: Unexpectedly, quality flaws measured by PMD turned out not to affect the acceptance of a pull request at all. As suggested by other works, other factors such as the reputation of the maintainer and the importance of the delivered feature might be more important than other qualities in terms of pull request acceptance.

Conclusions:. Researchers have already investigated the influence of the developers’ reputation and the pull request acceptance. This is the first work investigating code style violations and specifically PMD rules. We recommend that researchers further investigate this topic to understand if different measures or different tools could provide some useful measures.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, LUT University
Contributors: Lenarduzzi, V., Nikkola, V., Saarimäki, N., Taibi, D.
Number of pages: 14
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 171
Article number: 110806
ISSN (Print): 0164-1212
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture
Keywords: Machine learning, PMD rules, Pull requests

Bibliographical note

EXT="Lenarduzzi, Valentina"
INT=comp,"Nikkola, Vili"

Source: Scopus
Source ID: 85090024069

Research output: Contribution to journalArticleScientificpeer-review

Does migrating a monolithic system to microservices decrease the technical debt?

Background: The migration from a monolithic system to microservices requires a deep refactoring of the system. Therefore, such a migration usually has a big economic impact and companies tend to postpone several activities during this process, mainly to speed up the migration itself, but also because of the demand for releasing new features.

Objective: We monitored the technical debt of an SME while it migrated from a legacy monolithic system to an ecosystem of microservices. Our goal was to analyze changes in the code technical debt before and after the migration to microservices.

Method: We conducted a case study analyzing more than four years of the history of a twelve-year-old project (280K Lines of Code) where two teams extracted five business processes from the monolithic system as microservices. For the study, we first analyzed the technical debt with SonarQube and then performed a qualitative study with company members to understand the perceived quality of the system and the motivation for possibly postponed activities.

Results: The migration to microservices helped to reduce the technical debt in the long run. Despite an initial spike in the technical debt due to the development of the new microservice, after a relatively short period of time the technical debt tended to grow slower than in the monolithic system.

General information

Publication status: Published
MoE publication type: A2 Review article in a scientific journal
Organisations: Computing Sciences, LUT University
Contributors: Lenarduzzi, V., Lomio, F., Saarimäki, N., Taibi, D.
Number of pages: 16
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 169
Article number: 110710
ISSN (Print): 0164-1212
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture
Keywords: Architectural debt, Code quality, Microservices, Refactoring, Technical debt

Bibliographical note

EXT="Lenarduzzi, Valentina"

Source: Scopus
Source ID: 85087383887

Research output: Contribution to journalReview ArticleScientificpeer-review

Exploration and exploitation of sensorimotor contingencies for a cognitive embodied agent

The modelling of cognition is playing a major role in robotics. Indeed, robots need to learn, adapt and plan their actions in order to interact with their environment. To do so, approaches like embodiment and enactivism propose to ground sensorimotor experience in the robot's body to shape the development of cognition. In this work, we focus on the role of memory during learning in a closed loop. As sensorimotor contingencies, we consider a robot arm that moves a baby mobile toy to get visual reward. First, the robot explores the continuous sensorimotor space by associating visual stimuli to motor actions through motor babbling. After exploration, the robot uses the experience from its memory and exploits it, thus optimizing its motion to perceive more visual stimuli. The proposed approach uses Dynamic Field Theory and is integrated in the GummiArm, a 3D printed humanoid robot arm. The results indicate a higher visual neural activation after motion learning and show the benefits of an embodied babbling strategy.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation Technology and Mechanical Engineering, Research group: Robotics and Automation
Contributors: Houbre, Q., Angleraud, A., Pieters, R.
Number of pages: 9
Pages: 546-554
Publication date: 2020

Host publication information

Title of host publication: ICAART 2020 - Proceedings of the 12th International Conference on Agents and Artificial Intelligence
Volume: 2
Publisher: SCITEPRESS
Editors: Rocha, A., Steels, L., van den Herik, J.
ISBN (Electronic): 9789897583957
ASJC Scopus subject areas: Artificial Intelligence, Software
Keywords: Cognitive Robotics, Dynamic Neural Fields, Embodiment, Sensorimotor Contingencies

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

FinnForest dataset: A forest landscape for visual SLAM

This paper presents a novel challenging dataset that offers a new landscape of testing material for mobile robotics, autonomous driving research, and forestry operation. In contrast to common urban structures, we explore an unregulated natural environment to exemplify sub-urban and forest environment. The sequences provide two-natured data where each place is visited in summer and winter conditions. The vehicle used for recording is equipped with a sensor rig that constitutes four RGB cameras, an Inertial Measurement Unit, and a Global Navigation Satellite System receiver. The sensors are synchronized based on non-drifting timestamps. The dataset provides trajectories of varying complexity both for the state of the art visual odometry approaches and visual simultaneous localization and mapping algorithms. The full dataset and toolkits are available for download at: http://urn.fi/urn:nbn:fi:att:9b8157a7-1e0f-47c2-bd4e-a19a7e952c0d. As an alternative, you can browse for the dataset using the article title at: http://etsin.fairdata.fi.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: 3D MEDIA, JC Inertial Oy
Contributors: Ali, I., Durmush, A., Suominen, O., Yli-Hietanen, J., Peltonen, S., Collin, J., Gotchev, A.
Number of pages: 13
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: ROBOTICS AND AUTONOMOUS SYSTEMS
Volume: 132
Article number: 103610
ISSN (Print): 0921-8890
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Software, Mathematics(all), Computer Science Applications
Keywords: Autonomous driving, Computer vision, Dataset, Field robotics, Forest, Localization, Mapping, Mobile robotics, Navigation, SLAM, Stereo, Visual odometry
Electronic versions: 
Source: Scopus
Source ID: 85089744434

Research output: Contribution to journalArticleScientificpeer-review

IoT-CryptoDiet: Implementing a lightweight cryptographic library based on ecdh and ecdsa for the development of secure and rivacy-preserving protocols in contiki-ng

Even though the idea of transforming basic objects to smart objects with the aid sensors is not new, it is only now that we have started seeing the incredible impact of this digital transformation in our societies. There is no doubt that the Internet of Things (IoT) has the power to change our world and drive us to a complete social evolution. This is something that has been well understood by the research and industrial communities that have been investing significant resources in the field of IoT. In business and industry, there are thousands of IoT use cases and real-life IoT deployments across a variety of sectors (e.g. industry 4.0 and smart factories, smart cities, etc.). However, due to the vastly resource-constrained nature of the devices used in IoT, implementing secure and privacy-preserving services, using, for example, standard asymmetric cryptographic algorithms, has been a real challenge. The majority of IoT devices on the market currently employ the use of various forms of symmetric cryptography such as key pre-distribution. The overall efficiency of such implementations correlates directly to the size of the IoT environment and the deployment method. In this paper, we implement a lightweight cryptographic library that can be used to secure communication protocols between multiple communicating nodes without the need for external trusted entities or a server. Our work focuses on extending the functionalities of the User Datagram Protocol (UDP) broadcast application on the Contiki-NG Operating System (OS) platform.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Frimpong, E., Michalas, A.
Number of pages: 11
Pages: 101-111
Publication date: 2020

Host publication information

Title of host publication: IoTBDS 2020 - Proceedings of the 5th International Conference on Internet of Things, Big Data and Security
Publisher: SCITEPRESS
Editors: Wills, G., Kacsuk, P., Chang, V.
ISBN (Electronic): 9789897584268
ASJC Scopus subject areas: Software, Computer Networks and Communications
Keywords: Contiki-NG, Elliptic Curve Cryptography, Key Distribution, Privacy, Wireless Sensor Networks.
Electronic versions: 
Source: Scopus
Source ID: 85089469229

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

On the diffuseness of technical debt items and accuracy of remediation time when using SonarQube

Context. Among the static analysis tools available, SonarQube is one of the most used. SonarQube detects Technical Debt (TD) items—i.e., violations of coding rules—and then estimates TD as the time needed to remedy TD items. However, practitioners are still skeptical about the accuracy of remediation time estimated by the tool. Objective. In this paper, we analyze both diffuseness of TD items and accuracy of remediation time, estimated by SonarQube, to fix TD items on a set of 21 open-source Java projects. Method. We designed and conducted a case study where we asked 81 junior developers to fix TD items and reduce the TD of 21 projects. Results. We observed that TD items are diffused in the analyzed projects and most items are code smells. Moreover, the results point out that the remediation time estimated by SonarQube is inaccurate and, as compared to the actual time spent to fix TD items, is in most cases overestimated. Conclusions. The results of our study are promising for practitioners and researchers. The former can make more aware decisions during project execution and resource management, the latter can use this study as a starting point for improving TD estimation models.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Universita degli Studi di Bari, LUT University
Contributors: Baldassarre, M. T., Lenarduzzi, V., Romano, S., Saarimäki, N.
Number of pages: 18
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Information and Software Technology
Volume: 128
Article number: 106377
ISSN (Print): 0950-5849
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Case study, Effort estimation, Remediation time, Sonarqube, Technical debt

Bibliographical note

EXT="Lenarduzzi, Valentina"

Source: Scopus
Source ID: 85088664918

Research output: Contribution to journalArticleScientificpeer-review

Patterns for serverless functions (Function-as-a-Service): A multivocal literature review

[Context] Serverless is a recent technology that enables companies to reduce the overhead for provisioning, scaling and in general managing the infrastructure. Companies are increasingly adopting Serverless, by migrating existing applications to this new paradigm. Different practitioners proposed patterns for composing and managing serverless functions. However, some of these patterns offer different solutions to solve the same problem, which makes it hard to select the most suitable solution for each problem. [Goal] In this work, we aim at supporting practitioners in understanding the different patterns, by classifying them and reporting possible benefits and issues. [Method]We adopted a multivocal literature review process, surveying peer-reviewed and grey literature and classifying patterns (common solutions to solve common problems), together with benefits and issues. [Results] Among 24 selected works, we identified 32 patterns that we classified as orchestration, aggregation, event-management, availability, communication, and authorization. [Conclusion] Practitioners proposed a list of fairly consistent patterns, even if a small number of patterns proposed different solutions to similar problems. Some patterns emerged to circumvent some serverless limitations, while others for some classical technical problems (e.g. publisher/subscriber).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Free University of Bolzano-Bozen
Contributors: Taibi, D., El Ioini, N., Pahl, C., Niederkofler, J. R. S.
Number of pages: 12
Pages: 181-192
Publication date: 2020

Host publication information

Title of host publication: CLOSER 2020 - Proceedings of the 10th International Conference on Cloud Computing and Services Science
Volume: 1
Publisher: SCITEPRESS
Editors: Ferguson, D., Helfert, M., Pahl, C.
ISBN (Electronic): 9789897584244
ASJC Scopus subject areas: Computer Science (miscellaneous), Computer Science Applications, Software
Keywords: Cloud, Function as a Service, Serverless, Serverless Functions
Source: Scopus
Source ID: 85088373702

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Redundancy-based visual tool center point pose estimation for long-reach manipulators

In this paper, we study a visual sensing scheme for 6 degree-of-freedom (DOF) tool center point (TCP) pose estimation of large-scale, long-reach manipulators. A sensor system is proposed, designed especially for mining manipulators, comprising a stereo camera running a simultaneous localization and mapping (SLAM) algorithm near the TCP and multiple cameras that track a fiducial marker attached near the stereo camera. In essence, the TCP pose is formulated using two different routes in a co-operative (eye-in-hand/eye-to-hand) manner using data fusion, with the goal of increasing the system's fault tolerance and robustness via sensor redundancy. The system is studied in offline data analysis based on real-world measurements recorded using a hydraulic 6 DOF robotic manipulator with a 5 m reach. The SLAM pose trajectory is obtained using the open source ORB-SLAM2 Stereo algorithm, whereas marker-based tracking is realized with a high-end motion capture system. For reference measurements, the pose trajectory is also formulated using joint encoders and a kinematic model of the manipulator. Results of the 6 DOF pose estimation using the proposed sensor system are presented, with future work and key challenges also highlighted.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation Technology and Mechanical Engineering, Research group: Innovative Hydraulic Automation, Sandvik Mining and Construction Oy
Contributors: Mäkinen, P., Mustalahti, P., Launis, S., Mattila, J.
Number of pages: 7
Pages: 1387-1393
Publication date: 2020

Host publication information

Title of host publication: 2020 IEEE/ASME International Conference on Advanced Intelligent Mechatronics, AIM 2020
Publisher: IEEE
ISBN (Print): 978-1-7281-6795-4
ISBN (Electronic): 9781728167947

Publication series

Name: IEEE/ASME International Conference on Advanced Intelligent Mechatronics
ISSN (Print): 2159-6247
ISSN (Electronic): 2159-6255
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Computer Science Applications, Software

Bibliographical note

EXT="Launis, Sirpa"
JUFOID=73592

Source: Scopus
Source ID: 85090392663

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Shearlet Transform-Based Light Field Compression under Low Bitrates

Light field (LF) acquisition devices capture spatial and angular information of a scene. In contrast with traditional cameras, the additional angular information enables novel post-processing applications, such as 3D scene reconstruction, the ability to refocus at different depth planes, and synthetic aperture. In this paper, we present a novel compression scheme for LF data captured using multiple traditional cameras. The input LF views were divided into two groups: key views and decimated views. The key views were compressed using the multi-view extension of high-efficiency video coding (MV-HEVC) scheme, and decimated views were predicted using the shearlet-transform-based prediction (STBP) scheme. Additionally, the residual information of predicted views was also encoded and sent along with the coded stream of key views. The proposed scheme was evaluated over a benchmark multi-camera based LF datasets, demonstrating that incorporating the residual information into the compression scheme increased the overall peak signal to noise ratio (PSNR) by 2 dB. The proposed compression scheme performed significantly better at low bit rates compared to anchor schemes, which have a better level of compression efficiency in high bit-rate scenarios. The sensitivity of the human vision system towards compression artifacts, specifically at low bit rates, favors the proposed compression scheme over anchor schemes.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: 3D MEDIA, Computing Sciences, Mid Sweden University, Sundsvall
Contributors: Ahmad, W., Vagharshakyan, S., Sjostrom, M., Gotchev, A., Bregovic, R., Olsson, R.
Number of pages: 12
Pages: 4269-4280
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Image Processing
Volume: 29
ISSN (Print): 1057-7149
Original language: English
ASJC Scopus subject areas: Software, Computer Graphics and Computer-Aided Design
Keywords: Light field (LF) coding, multi-view extension of high-efficiency video coding (MV-HEVC), multiple camera system (MCS) coding, shearlet
Source: Scopus
Source ID: 85079506505

Research output: Contribution to journalArticleScientificpeer-review

User experience of stereo and spatial audio in 360° live music videos

360° music videos are becoming prevalent in music entertainment. Still, academic studies of the 360° live music experience covering both audio and visual experience are scarce. In this paper, we present a study of user experience of stereo and spatial audio in a 360° live music video setting with two different display types. The research was conducted in the form of a laboratory experiment, in which 20 participants watched and evaluated stereo and spatial audio versions of the same music video using a flat computer display and a head-mounted display (HMD). Based on the results, spatial audio combined with HMD scored highest in the quantitative metrics of perceived audio quality, presence, and overall listening experience. However, qualitative findings reveal that this combination does not fit well with users' listening habits. While nine participants preferred to use headphones to listen to music, thirteen participants viewed music listening as a secondary task-making the use of HMDs less suitable.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Tampere University, Tampere University of Applied Sciences
Contributors: Holm, J., Väänänen, K., Battah, A.
Number of pages: 8
Pages: 134-141
Publication date: 2020

Host publication information

Title of host publication: AcademicMindtrek 2020 - Proceedings of the 23rd International Academic Mindtrek Conference : January 2020, Tampere
Publisher: ACM
ISBN (Electronic): 9781450377744
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Vision and Pattern Recognition, Computer Networks and Communications
Keywords: 360° video, ambisonics, head-mounted display, music video, spatial audio, stereo, user experience, virtual reality

Bibliographical note

EXT="Holm, Jukka"
INT=comp,"Battah, Anas"

Source: Scopus
Source ID: 85080964162

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Validating effectiveness of safety requirements' compliance evaluation in process assessments

Safety is the primary concern when developing systems containing software in the nuclear power domain. Process assessments are used to ensure quality of the development processes for safety-critical systems. Regulators of the nuclear power industry have increased requirements concerning the systems development processes. Now, process assessments are integrated in the qualification of the systems and are expected to provide information not only based on the assessment model but also about the domain-specific requirements. Therefore, a specific activity, compliance evaluation, was inserted into the assessment process to provide detailed information that supports analysis of the compliance to the domain standards. Compliance evaluation utilizes assessment findings to create evidence of the relevant domain-specific requirements. The main purpose of this study is to validate effectiveness of compliance evaluation by analyzing assessment findings and their relation to the requirements of a safety-critical domain. The analysis is based on representing the data in compliance evaluation reports as binary relations. The results of this analysis indicate that process assessment findings are also relevant when evaluating compliance to other sets of requirements. The results can significantly support the trustworthiness of the process assessment method and ensure effective use of process assessments.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Software Engineering and Intelligent Systems, Research group: Data-analytics and Optimization, Finnish Software Measurement Association
Contributors: Varkoi, T., Mäkinen, T., Cameron, F., Nevalainen, R.
Number of pages: 16
Publication date: 2020
Peer-reviewed: Yes
Early online date: 2019

Publication information

Journal: Journal of Software: Evolution and Process
Volume: 32
Issue number: 3
Article number: e2177
ISSN (Print): 2047-7473
Original language: English
ASJC Scopus subject areas: Software
Keywords: Nuclear SPICE, process assessment, safety, systems engineering

Bibliographical note

EXT="Varkoi, Timo"
EXT="Nevalainen, Risto"

Source: Scopus
Source ID: 85080987236

Research output: Contribution to journalArticleScientificpeer-review

Bayesian receiver operating characteristic metric for linear classifiers

We propose a novel classifier accuracy metric: the Bayesian Area Under the Receiver Operating Characteristic Curve (CBAUC). The method estimates the area under the ROC curve and is related to the recently proposed Bayesian Error Estimator. The metric can assess the quality of a classifier using only the training dataset without the need for computationally expensive cross-validation. We derive a closed-form solution of the proposed accuracy metric for any linear binary classifier under the Gaussianity assumption, and study the accuracy of the proposed estimator using simulated and real-world data. These experiments confirm that the closed-form CBAUC is both faster and more accurate than conventional AUC estimators.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: Computational Systems Biology, Computing Sciences, AI Virtanen Institute for Molecular Sciences, University of Eastern Finland
Contributors: Hassan, S. S., Huttunen, H., Niemi, J., Tohka, J.
Number of pages: 8
Pages: 52-59
Publication date: 1 Dec 2019
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 128
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2019): CiteScore 6.3 SJR 0.848 SNIP 2.021
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
Keywords: Bayesian error estimation, Classification, Receiver operating characteristic curve

Bibliographical note

EXT="Tohka, Jussi"

Source: Scopus
Source ID: 85071016385

Research output: Contribution to journalArticleScientificpeer-review

Software architecture design in global software development: An empirical study

In Global Software Development (GSD), the additional complexity caused by global distance requires processes to ease collaboration difficulties, reduce communication overhead, and improve control. How development tasks are broken down, shared and prioritized is key to project success. While the related literature provides some support for architects involved in GSD, guidelines are far from complete. This paper presents a GSD Architectural Practice Framework reflecting the views of software architects, all of whom are working in a distributed setting. In-depth interviews with architects from seven different GSD organizations revealed a complex set of challenges and practices. We found that designing software for distributed teams requires careful selection of practices that support understanding and adherence to defined architectural plans across sites. Teams used Scrum which aided communication, and Continuous Integration which helped solve synchronization issues. However, teams deviated from the design, causing conflicts. Furthermore, there needs to be a balance between the self-organizing Scrum team methodology and the need to impose architectural design decisions across distributed sites. The research presented provides an enhanced understanding of architectural practices in GSD companies. Our GSD Architectural Practice Framework gives practitioners a cohesive set of warnings, which for the most part, are matched by recommendations.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research area: Software engineering, University of Limerick
Contributors: Sievi-Korte, O., Richardson, I., Beecham, S.
Publication date: 1 Dec 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 158
Article number: 110400
ISSN (Print): 0164-1212
Ratings: 
  • Scopus rating (2019): CiteScore 7.8 SJR 0.772 SNIP 2.387
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture
Keywords: Empirical study, Global software development, GSD, GSE, Scrum, Software architecture
URLs: 
Source: Scopus
Source ID: 85072283236

Research output: Contribution to journalArticleScientificpeer-review

Promoting local culture and enriching airport experiences through interactive storytelling

Experiences in airports may shape future travel plans and contribute to tourism destination development. However, a chaotic environment and time-consuming procedural routines in airports may result in negative associations towards the host country and its culture. Despite the existence of assistive airport applications, little attention is given to facilitating travelers’ engagement with cultural exploration. This paper introduces a concept of interactive personalized storytelling that provides both a cultural learning adventure and connection to local retailing. Our application generates an imaginative Finnish storyline unique to every user to guide them through local shops in the airport. A field evaluation was conducted with 15 travelers of different nationalities. Travelers perceived the interactive storytelling experience as an interesting and unique way to spend waiting time at the airport while increasing cultural exposure. Moreover, we found this method to be effective in persuading travelers to explore local products at the airport. Further, our results give insight to designing storytelling applications for large public places.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Lapland University of Applied Sciences, Tampere University, Tampere University, Tampere University
Contributors: Burova, A., Kelling, C., Keskinen, T., Hakulinen, J., Kallioniemi, P., Väätäjä, H., Turunen, M.
Number of pages: 7
Publication date: 26 Nov 2019

Host publication information

Title of host publication: MUM 2019 - 18th International Conference on Mobile and Ubiquitous Multimedia, Proceedings
Publisher: Association for Computing Machinery
Editors: Jacucci, G., Paterno, F., Rohs, M., Santoro, C.
Article number: 3365640
ISBN (Electronic): 9781450376242

Publication series

Name: ACM International Conference Proceeding Series
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Airport experience, Digital storytelling, Field study, Mobile application

Bibliographical note

EXT="Väätäjä, Heli"

Source: Scopus
Source ID: 85076809996

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Programming languages for data-Intensive HPC applications: A systematic mapping study

A major challenge in modelling and simulation is the need to combine expertise in both software technologies and a given scientific domain. When High-Performance Computing (HPC) is required to solve a scientific problem, software development becomes a problematic issue. Considering the complexity of the software for HPC, it is useful to identify programming languages that can be used to alleviate this issue. Because the existing literature on the topic of HPC is very dispersed, we performed a Systematic Mapping Study (SMS) in the context of the European COST Action cHiPSet. This literature study maps characteristics of various programming languages for data-intensive HPC applications, including category, typical user profiles, effectiveness, and type of articles. We organised the SMS in two phases. In the first phase, relevant articles are identified employing an automated keyword-based search in eight digital libraries. This lead to an initial sample of 420 papers, which was then narrowed down in a second phase by human inspection of article abstracts, titles and keywords to 152 relevant articles published in the period 2006–2018. The analysis of these articles enabled us to identify 26 programming languages referred to in 33 of relevant articles. We compared the outcome of the mapping study with results of our questionnaire-based survey that involved 57 HPC experts. The mapping study and the survey revealed that the desired features of programming languages for data-intensive HPC applications are portability, performance and usability. Furthermore, we observed that the majority of the programming languages used in the context of data-intensive HPC applications are text-based general-purpose programming languages. Typically these have a steep learning curve, which makes them difficult to adopt. We believe that the outcome of this study will inspire future research and development in programming languages for data-intensive HPC applications.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: MMDM, Universidade Nova de Lisboa, University of Torino, Der Technischen Universitat Wien Fakultät für Elektrotechnik und Informationstechnik, University of Stirling, Universidade de Lisboa, University of Latvia, NOVA University of Lisbon, University of Amsterdam, Aristotle University of Thessaloniki, Linköping University, Queen's University, Belfast, Northern Ireland, Linnaeus University, Kalmar, Instituto Superior de Engenharia de Lisboa
Contributors: Amaral, V., Norberto, B., Goulão, M., Aldinucci, M., Benkner, S., Bracciali, A., Carreira, P., Celms, E., Correia, L., Grelck, C., Karatza, H., Kessler, C., Kilpatrick, P., Martiniano, H., Mavridis, I., Pllana, S., Respício, A., Simão, J., Veiga, L., Visa, A.
Number of pages: 17
Publication date: 8 Nov 2019
Peer-reviewed: Yes

Publication information

Journal: Parallel Computing
Volume: 91
Article number: 102584
ISSN (Print): 0167-8191
Ratings: 
  • Scopus rating (2019): CiteScore 2.9 SJR 0.346 SNIP 1.104
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Hardware and Architecture, Computer Networks and Communications, Computer Graphics and Computer-Aided Design, Artificial Intelligence
Keywords: Big data, Data-intensive applications, Domain-Specific language (DSL), General-Purpose language (GPL), High performance computing (HPC), Programming languages, Systematic mapping study (SMS)
Source: Scopus
Source ID: 85076201522

Research output: Contribution to journalArticleScientificpeer-review

Action-Oriented Programming Model: Collective Executions and Interactions in the Fog

Today's dominant design for the Internet of Things (IoT) is a Cloud-based system, where devices transfer their data to a back-end and in return receive instructions on how to act. This view is challenged when delays caused by communication with the back-end become an obstacle for IoT applications with, for example, stringent timing constraints. In contrast, Fog Computing approaches, where devices communicate and orchestrate their operations collectively and closer to the origin of data, lack adequate tools for programming secure interactions between humans and their proximate devices at the network edge. This paper fills the gap by applying Action-Oriented Programming (AcOP) model for this task. While originally the AcOP model was proposed for Cloud-based infrastructures, presently it is re-designed around the notion of coalescence and disintegration, which enable the devices to collectively and autonomously execute their operations in the Fog by serving humans in a peer-to-peer fashion. The Cloud's role has been minimized—it is being leveraged as a development and deployment platform.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Electrical Engineering, Department of Computer Science, University of Helsinki, National Research University Higher School of Economics
Contributors: Mäkitalo, N., Aaltonen, T., Raatikainen, M., Ometov, A., Andreev, S., Koucheryavy, Y., Mikkonen, T.
Publication date: 1 Nov 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 157
Article number: 110391
ISSN (Print): 0164-1212
Ratings: 
  • Scopus rating (2019): CiteScore 7.8 SJR 0.772 SNIP 2.387
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture
Keywords: Edge computing, Fog Computing, Programming model, Proximity-based computing, Socio-technical systems
Electronic versions: 

Bibliographical note

EXT="Mäkitalo, Niko"
EXT="Mikkonen, Tommi"

Source: Scopus
Source ID: 85070882337

Research output: Contribution to journalArticleScientificpeer-review

Feasibility of FPGA accelerated IPsec on cloud

Hardware acceleration for famous VPN solution, IPsec, has been widely researched already. Still it is not fully covered and the increasing latency, throughput, and feature requirements need further evaluation. We propose an IPsec accelerator architecture in an FPGA and explain the details that need to be considered for a production ready design. This research considers the IPsec packet processing without IKE to be offloaded on an FPGA in an SDN network. Related work performance rates in 64 byte packet size for throughput is 1–2 Gbps with 0.2 ms latency in software, and 1–4 Gbps with unknown latencies for hardware solutions. Our proposed architecture is capable to host 1000 concurrent tunnels and have 10 Gbps throughput with only 10 µs latency in our test network. Therefore the proposed design is efficient even with voice or video encryption. The architecture is especially designed for data centers and locations with vast number of concurrent IPsec tunnels. The research confirms that FPGA based hardware acceleration increases performance and is feasible to integrate with the other server infrastructure.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research area: Information security, Baseband ASIC R&D, Nokia Siemens Networks
Contributors: Vajaranta, M., Oinonen, A., Hämäläinen, T. D., Viitamäki, V., Markunmäki, J., Kulmala, A.
Publication date: 1 Nov 2019
Peer-reviewed: Yes

Publication information

Journal: Microprocessors and Microsystems
Volume: 71
Article number: 102861
ISSN (Print): 0141-9331
Ratings: 
  • Scopus rating (2019): CiteScore 3 SJR 0.303 SNIP 0.879
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications, Artificial Intelligence
Keywords: Accelerator, IPsec, Offloading, SDN

Bibliographical note

EXT="Viitamäki, Vili"
EXT="Kulmala, Ari"

Source: Scopus
Source ID: 85070320729

Research output: Contribution to journalArticleScientificpeer-review

An icon that everyone wants to click: How perceived aesthetic qualities predict app icon successfulness

Mobile app markets have been touted as fastest growing marketplaces in the world. Every day thousands of apps are published to join millions of others on app stores. The competition for top grossing apps and market visibility is fierce. The way an app is visually represented can greatly contribute to the amount of attention an icon receives and to its consequent commercial performance. Therefore, the icon of the app is of crucial importance as it is the first point of contact with the potential user/customer amidst the flood of information. Those apps that fail to arouse attention through their icons danger their commercial performance in the market where consumers browse past hundreds of icons daily. Using semantic differential scale (22 adjective pairs), we investigate the relationship between consumer perceptions of app icons and icon successfulness, measured by 1)overall evaluation of the icon, 2)willingness to click the icon, 3)willingness to download the imagined app and, 4)willingness to purchase the app. The study design was a vignette study with random participant (n = 569)assignment to evaluate 4 icons (n = 2276)from a total of pre-selected 68 game app icons across 4 categories (concrete, abstract, character and text). Results show that consumers are more likely to interact with app icons that are aesthetically pleasing and convey good quality. Particularly, app icons that are perceived unique, realistic and stimulating lead to more clicks, downloads and purchases.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Gamification Group, Tampere University, University of Turku
Contributors: Jylhä, H., Hamari, J.
Number of pages: 13
Pages: 73-85
Publication date: 1 Oct 2019
Peer-reviewed: Yes

Publication information

Journal: International Journal of Human Computer Studies
Volume: 130
ISSN (Print): 1071-5819
Ratings: 
  • Scopus rating (2019): CiteScore 5.8 SJR 0.756 SNIP 2.163
Original language: English
ASJC Scopus subject areas: Software, Human Factors and Ergonomics, Education, Engineering(all), Human-Computer Interaction, Hardware and Architecture
Keywords: Aesthetics, Digital marketing, Graphical user interfaces, Iconography, Mobile apps, Semantic differential
Electronic versions: 
Source: Scopus
Source ID: 85067993498

Research output: Contribution to journalArticleScientificpeer-review

Automatic word count estimation from daylong child-centered recordings in various language environments using language-independent syllabification of speech

Automatic word count estimation (WCE) from audio recordings can be used to quantify the amount of verbal communication in a recording environment. One key application of WCE is to measure language input heard by infants and toddlers in their natural environments, as captured by daylong recordings from microphones worn by the infants. Although WCE is nearly trivial for high-quality signals in high-resource languages, daylong recordings are substantially more challenging due to the unconstrained acoustic environments and the presence of near- and far-field speech. Moreover, many use cases of interest involve languages for which reliable ASR systems or even well-defined lexicons are not available. A good WCE system should also perform similarly for low- and high-resource languages in order to enable unbiased comparisons across different cultures and environments. Unfortunately, the current state-of-the-art solution, the LENA system, is based on proprietary software and has only been optimized for American English, limiting its applicability. In this paper, we build on existing work on WCE and present the steps we have taken towards a freely available system for WCE that can be adapted to different languages or dialects with a limited amount of orthographically transcribed speech data. Our system is based on language-independent syllabification of speech, followed by a language-dependent mapping from syllable counts (and a number of other acoustic features) to the corresponding word count estimates. We evaluate our system on samples from daylong infant recordings from six different corpora consisting of several languages and socioeconomic environments, all manually annotated with the same protocol to allow direct comparison. We compare a number of alternative techniques for the two key components in our system: speech activity detection and automatic syllabification of speech. As a result, we show that our system can reach relatively consistent WCE accuracy across multiple corpora and languages (with some limitations). In addition, the system outperforms LENA on three of the four corpora consisting of different varieties of English. We also demonstrate how an automatic neural network-based syllabifier, when trained on multiple languages, generalizes well to novel languages beyond the training data, outperforming two previously proposed unsupervised syllabifiers as a feature extractor for WCE.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Aalto University, Laboratoire de Sciences Cognitives et Psycholinguistique, Carnegie Mellon University, University of Manitoba, Max Planck Institute for Psycholinguistics, CONICET, Duke University
Contributors: Räsänen, O., Seshadri, S., Karadayi, J., Riebling, E., Bunce, J., Cristia, A., Metze, F., Casillas, M., Rosemberg, C., Bergelson, E., Soderstrom, M.
Number of pages: 18
Pages: 63-80
Publication date: 1 Oct 2019
Peer-reviewed: Yes

Publication information

Journal: Speech Communication
Volume: 113
ISSN (Print): 0167-6393
Ratings: 
  • Scopus rating (2019): CiteScore 4.2 SJR 0.554 SNIP 1.297
Original language: English
ASJC Scopus subject areas: Software, Modelling and Simulation, Communication, Language and Linguistics, Linguistics and Language, Computer Vision and Pattern Recognition, Computer Science Applications
Keywords: Automatic syllabification, Daylong recordings, Language acquisition, Noise robustness, Word count estimation
Electronic versions: 
Source: Scopus
Source ID: 85070952723

Research output: Contribution to journalArticleScientificpeer-review

DevOps in practice: A multiple case study of five companies

Context: DevOps is considered important in the ability to frequently and reliably update a system in operational state. DevOps presumes cross-functional collaboration and automation between software development and operations. DevOps adoption and implementation in companies is non-trivial due to required changes in technical, organisational and cultural aspects. Objectives: This exploratory study presents detailed descriptions of how DevOps is implemented in practice. The context of our empirical investigation is web application and service development in small and medium sized companies. Method: A multiple-case study was conducted in five different development contexts with successful DevOps implementations since its benefits, such as quick releases and minimum deployment errors, were achieved. Data was mainly collected through interviews with 26 practitioners and observations made at the companies. Data was analysed by first coding each case individually using a set of predefined themes and thereafter perform a cross-case synthesis. Results: Our analysis yielded some of the following results: (i) software development team attaining ownership and responsibility to deploy software changes in production is crucial in DevOps. (ii) toolchain usage and support in deployment pipeline activities accelerates the delivery of software changes, bug fixes and handling of production incidents. (ii) the delivery speed to production is affected by context factors, such as manual approvals by the product owner (iii) steep learning curve for new skills is experienced by both software developers and operations staff, who also have to cope with working under pressure. Conclusion: Our findings contributes to the overall understanding of DevOps concept, practices and its perceived impacts, particularly in small and medium sized companies. We discuss two practical implications of the results.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, University of Oulu, Aalto University, University of Helsinki
Contributors: Lwakatare, L. E., Kilamo, T., Karvonen, T., Sauvola, T., Heikkilä, V., Itkonen, J., Kuvaja, P., Mikkonen, T., Oivo, M., Lassenius, C.
Number of pages: 14
Pages: 217-230
Publication date: 1 Oct 2019
Peer-reviewed: Yes

Publication information

Journal: Information and Software Technology
Volume: 114
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2019): CiteScore 7.6 SJR 0.781 SNIP 2.555
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Agile, Continuous deployment, Development, DevOps, Operations

Bibliographical note

EXT="Mikkonen, Tommi"

Source: Scopus
Source ID: 85068546035

Research output: Contribution to journalArticleScientificpeer-review

The Double Shadowed κ-μ Fading Model

In this paper, we introduce a new fading model which is capable of characterizing both the shadowing of the dominant component and composite shadowing which may exist in wireless channels. More precisely, this new model assumes a κ-μ envelope where the dominant component is fluctuated by a Nakagami-m random variable (RV) which is preceded (or succeeded) by a secondary round of shadowing brought about by an inverse Nakagami-m RV. We conveniently refer to this as the double shadowed κ-μ fading model. In this context, novel closed-form and analytical expressions are developed for a range of channel related statistics, such as the probability density function, cumulative distribution function, and moments. All of the derived expressions have been validated through Monte-Carlo simulations and reduction to a number of well-known special cases. It is worth highlighting that the proposed fading model offers remarkable flexibility as it includes the κ-μ, η-μ, Rician shadowed, double shadowed Rician, κ-μ shadowed, κ-μ/inverse gamma and η-μ/inverse gamma distributions as special cases.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research group: Wireless Communications and Positioning, Electrical Engineering, Queen's University, Belfast, Northern Ireland, Universidade Estadual de Campinas, Center on Cyber-Physical Systems, Khalifa University, Tampere University of Applied Sciences
Contributors: Simmons, N., Nogueira Da Silva, C. R., Cotton, S. L., Sofotasios, P. C., Ki Yoo, S., Yacoub, M. D.
Publication date: 1 Oct 2019

Host publication information

Title of host publication: 2019 International Conference on Wireless and Mobile Computing, Networking and Communications, WiMob 2019
Publisher: IEEE
ISBN (Electronic): 9781728133164

Publication series

Name: International Conference on Wireless and Mobile Computing, Networking and Communications
ISSN (Print): 2161-9646
ISSN (Electronic): 2161-9654
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software
Source: Scopus
Source ID: 85077583520

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Tunable VVC Frame Partitioning based on Lightweight Machine Learning

Block partition structure is a critical module in video coding scheme to achieve significant gap of compression performance. Under the exploration of the future video coding standard, named Versatile Video Coding (VVC), a new Quad Tree Binary Tree (QTBT) block partition structure has been introduced. In addition to the QT block partitioning defined in High Efficiency Video Coding (HEVC) standard, new horizontal and vertical BT partitions are enabled, which drastically increases the encoding time compared to HEVC. In this paper, we propose a lightweight and tunable QTBT partitioning scheme based on a Machine Learning (ML) approach. The proposed solution uses Random Forest classifiers to determine for each coding block the most probable partition modes. To minimize the encoding loss induced by misclassification, risk intervals for classifier decisions are introduced in the proposed solution. By varying the size of risk intervals, tunable trade-off between encoding complexity reduction and coding loss is achieved. The proposed solution implemented in the JEM-7.0 software offers encoding complexity reductions ranging from 30average for only 0.7% to 3.0% Bjxntegaard Delta Rate (BDBR) increase in Random Access (RA) coding configuration, with very slight overhead induced by Random Forest. The proposed solution based on Random Forest classifiers is also efficient to reduce the complexity of the Multi-Type Tree (MTT) partitioning scheme under the VTM-5.0 software, with complexity reductions ranging from 25% to 61% in average for only 0.4% to 2.2% BD-BR increase.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, UBL, HTE/STR/MMP Gennevilliers
Contributors: Amestoy, T., Mercat, A., Hamidouche, W., Menard, D., Bergeron, C.
Publication date: 6 Sep 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Image Processing
ISSN (Print): 1057-7149
Ratings: 
  • Scopus rating (2019): CiteScore 15.6 SJR 2.893 SNIP 4.182
Original language: English
ASJC Scopus subject areas: Software, Computer Graphics and Computer-Aided Design
Keywords: Complexity Reduction, JEM, Machine Learning, QTBT, Random Forest, Video Compression, VTM, VVC
Source: Scopus
Source ID: 85072159338

Research output: Contribution to journalArticleScientificpeer-review

Model checking and validity in propositional and modal inclusion logics

Propositional and modal inclusion logic are formalisms that belong to the family of logics based on team semantics. This article investigates the model checking and validity problems of these logics. We identify complexity bounds for both problems, covering both lax and strict team semantics. By doing so, we come close to finalizing the programme that aims to completely classify the complexities of the basic reasoning problems for modal and propositional dependence, independence and inclusion logics.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Tampere University, Leibniz Universität Hannover, University of Helsinki, Hasselt University
Contributors: Hella, L., Kuusisto, A., Meier, A., Virtema, J.
Number of pages: 26
Pages: 605-630
Publication date: 1 Sep 2019
Peer-reviewed: Yes

Publication information

Journal: JOURNAL OF LOGIC AND COMPUTATION
Volume: 29
Issue number: 5
ISSN (Print): 0955-792X
Ratings: 
  • Scopus rating (2019): CiteScore 2.8 SJR 0.786 SNIP 1.481
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Arts and Humanities (miscellaneous), Hardware and Architecture, Logic
Keywords: complexity, Inclusion logic, model checking, team semantics, validity problem
Source: Scopus
Source ID: 85080893187

Research output: Contribution to journalArticleScientificpeer-review

Performance analysis of single-query 6-DoF camera pose estimation in self-driving setups

In this work, we consider the problem of single-query 6-DoF camera pose estimation, i.e. estimating the position and orientation of a camera by using reference images and a point cloud. We perform a systematic comparison of three state-of-the-art strategies for 6-DoF camera pose estimation: feature-based, photometric-based and mutual-information-based approaches. Two standard datasets with self-driving setups are used for experiments, and the performance of the studied methods is evaluated in terms of success rate, translation error and maximum orientation error. Building on the analysis of the results, we evaluate a hybrid approach that combines feature-based and mutual-information-based pose estimation methods to benefit from their complementary properties for pose estimation. Experiments show that (1) in cases with large appearance change between query and reference, the hybrid approach outperforms feature-based and mutual-information-based approaches by an average increment of 9.4% and 8.7% in the success rate, respectively; (2) in cases where query and reference images are captured at similar imaging conditions, the hybrid approach performs similarly as the feature-based approach, but outperforms both photometric-based and mutual-information-based approaches with a clear margin; (3) the feature-based approach is consistently more accurate than mutual-information-based and photometric-based approaches when at least 4 consistent matching points are found between the query and reference images.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Universidad Industrial de Santander, Czech Technical University in Prague
Contributors: Fu, J., Pertuz, S., Matas, J., Kämäräinen, J.
Pages: 58-73
Publication date: Sep 2019
Peer-reviewed: Yes

Publication information

Journal: Computer Vision and Image Understanding
Volume: 186
ISSN (Print): 1077-3142
Ratings: 
  • Scopus rating (2019): CiteScore 8.7 SJR 1.453 SNIP 2.255
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition
Keywords: 3D point cloud, Camera pose estimation, Hybrid method, Mutual information, Photometric matching, Self driving car

Bibliographical note

EXT="Matas, Jiri"

Source: Scopus
Source ID: 85067195521

Research output: Contribution to journalArticleScientificpeer-review

Game postmortems vs. developer Reddit AMAs: Computational analysis of developer communication

Postmortems and Reddit Ask Me Anything (AMA) threads represent communications of game developers through two different channels about their game development experiences, culture, processes, and practices. We carry out a quantitative text mining based comprehensive analysis of online available postmortems and AMA threads from game developers over multiple years. We find and analyze underlying topics from the postmortems and AMAs as well as their variation among the data sources and over time. The analysis is done based on structural topic modeling, a probabilistic modeling technique for text mining. The extracted topics reveal differing and common interests as well as their evolution of prevalence over time in the two text sources. We have found that postmortems put more emphasis on detail-oriented development aspects as well as technically-oriented game design problems whereas AMAs feature a wider variety of discussion topics that are related to a more general game development process, game-play and game-play experience related game design. The prevalences of the topics also evolve differently over time in postmortems versus AMAs.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Tampere University
Contributors: Lu, C., Peltonen, J., Nummenmaa, T.
Publication date: 26 Aug 2019

Host publication information

Title of host publication: Proceedings of the 14th International Conference on the Foundations of Digital Games, FDG 2019
Publisher: ACM
Editors: Khosmood, F., Pirker, J., Apperley, T., Deterding, S.
Article number: 22
ISBN (Electronic): 9781450372176
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Game development, Literature analysis, Postmortem analysis, Reddit, Text mining

Bibliographical note

INT=comp,"Peltonen, Jaakko"
INT=comp,"Lu, Chien"

Source: Scopus
Source ID: 85072819939

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Social features in hybrid board game marketing material

This paper identifies 7 key social features which appear in the marketing and promotional material of hybrid board games. The features are identified by exploring sources such as game websites and game boxes of 13 hybrid board game products. The material is analyzed in order to determine how social features related to hybrid game features are presented. As a result of the analysis, it became apparent that there are certain key social features which are presented as being important to players. The knowledge generated in this work acts as a view to how the industry sees hybridity in games as a tool for supporting social interaction, and how the industry wants to message it to consumers when they explore promotional material. The identified key social features can also be used as design knowledge for developing new games, as they give insight into popular social features in hybrid board games.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Tampere University
Contributors: Nummenmaa, T., Kankainen, V.
Publication date: 26 Aug 2019

Host publication information

Title of host publication: Proceedings of the 14th International Conference on the Foundations of Digital Games, FDG 2019
Publisher: ACM
Editors: Khosmood, F., Pirker, J., Apperley, T., Deterding, S.
Article number: 67
ISBN (Electronic): 9781450372176
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Board games, Design, Hybrid games, Marketing

Bibliographical note

INT=comp,"Kankainen, Vill"

Source: Scopus
Source ID: 85072820010

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Are architectural smells independent from code smells? An empirical study

Background. Architectural smells and code smells are symptoms of bad code or design that can cause different quality problems, such as faults, technical debt, or difficulties with maintenance and evolution. Some studies show that code smells and architectural smells often appear together in the same file. The correlation between code smells and architectural smells, however, is not clear yet; some studies on a limited set of projects have claimed that architectural smells can be derived from code smells, while other studies claim the opposite. Objective. The goal of this work is to understand whether architectural smells are independent from code smells or can be derived from a code smell or from one category of them. Method. We conducted a case study analyzing the correlations among 19 code smells, six categories of code smells, and four architectural smells. Results. The results show that architectural smells are correlated with code smells only in a very low number of occurrences and therefore cannot be derived from code smells. Conclusion. Architectural smells are independent from code smells, and therefore deserve special attention by researchers, who should investigate their actual harmfulness, and practitioners, who should consider whether and when to remove them.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, University Milano-Bicocca, Alten Italia
Contributors: Arcelli Fontana, F., Lenarduzzi, V., Roveda, R., Taibi, D.
Number of pages: 18
Pages: 139-156
Publication date: 1 Aug 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 154
ISSN (Print): 0164-1212
Ratings: 
  • Scopus rating (2019): CiteScore 7.8 SJR 0.772 SNIP 2.387
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture
Keywords: Architectural smells, Code smells, Empirical analysis, Technical debt
Source: Scopus
Source ID: 85064869442

Research output: Contribution to journalArticleScientificpeer-review

Enabling cybersecurity incident reporting and coordinated handling for maritime sector

The maritime industry is experiencing a new era of digital transformation. At the same time as the number of cyberattacks and cybersecurity incidents are increasing, cybersecurity awareness and incident reporting in this sector remains low. In this paper, we describe a cybersecurity incident reporting system for the maritime industry that aims to address this issue. The work focuses on autonomous and unmanned vessels, but can be equally applied to other areas of the maritime industry. The proposed approach has been evaluated experimentally and the results demonstrate its applicability and feasibility.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research area: Information security
Contributors: Silverajan, B., Vistiaho, P.
Number of pages: 8
Pages: 88-95
Publication date: 1 Aug 2019

Host publication information

Title of host publication: 2019 14th Asia Joint Conference on Information Security, AsiaJCIS 2019
Publisher: IEEE
ISBN (Electronic): 9781728125565
ASJC Scopus subject areas: Software, Information Systems and Management, Computer Networks and Communications, Safety, Risk, Reliability and Quality
Keywords: Cybersecurity incident exchange, Maritime cybersecurity, Smart ports, Smart ships

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Hermitian normalized Laplacian matrix for directed networks

In this paper, we extend and generalize the spectral theory of undirected networks towards directed networks by introducing the Hermitian normalized Laplacian matrix for directed networks. In order to start, we discuss the Courant–Fischer theorem for the eigenvalues of Hermitian normalized Laplacian matrix. Based on the Courant–Fischer theorem, we obtain a similar result towards the normalized Laplacian matrix of undirected networks: for each i ∈ {1, 2,…, n}, any eigenvalue of Hermitian normalized Laplacian matrix λ i ∈ [0, 2]. Moreover, we prove some special conditions if 0, or 2 is an eigenvalue of the Hermitian normalized Laplacian matrix L(X). On top of that, we investigate the symmetry of the eigenvalues of L(X)and the edge-version for the eigenvalue interlacing result. Finally we present two expressions for the coefficients of the characteristic polynomial of the Hermitian normalized Laplacian matrix. As an outlook, we sketch some novel and intriguing problems to which our apparatus could generally be applied.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Predictive Society and Data Analytics (PSDA), Guizhou University of Finance and Economics, University of Applied Sciences Upper Austria, Nankai University, Hall in Tyrol, Institute of Biosciences and Medical Technology
Contributors: Yu, G., Dehmer, M., Emmert-Streib, F., Jodlbauer, H.
Number of pages: 10
Pages: 175-184
Publication date: 1 Aug 2019
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 495
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2019): CiteScore 11.3 SJR 1.723 SNIP 2.688
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Characteristic polynomial, Courant–Fischer theorem, Directed networks, Eigenvalue interlacing inequality, Hermitian normalized Laplacian matrix
Source: Scopus
Source ID: 85065248406

Research output: Contribution to journalArticleScientificpeer-review

Real-time online drilling vibration analysis using data mining

While the data mining intermediaries play a critical role in the rock drilling industry, they also tend to provide an optimized real-time model for the drilling systems. In addition, proper online tool condition monitoring (OTOM) methods can improve the drilling performance by accessing real-time data. Hence, OTOM methods assist depreciating error and detect unspecified faults at early stages. In this study, we proposed appropriate OTOM algorithms to develop and enhance the quality of real-time systems and provide a solution to detect and categorize various stages of drilling operation with the aid of vibration signals (especially in terms of acceleration or velocity). In particular, the proposed methods in this article perform based on statistical approaches. Therefore, in order to recognize the drilling stages, we measured the Root Mean Square (RMS) values corresponding to the acceleration signals. In the meantime, we also succeeded to distinguish the drilling stages by employing estimated power spectral density (PSD) in the frequency domain. The acquired results in this publication confirm the real-time prediction and classification potential of the proposed methods for the different drilling stages and especially for the rock drilling engineering.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Automation Technology and Mechanical Engineering, Research group: Innovative Hydraulic Automation, Research group: MMDM, Tamlink Oy, Sandvik Mining and Construction Oy
Contributors: Zare, M., Huova, M., Visa, A., Launis, S.
Number of pages: 6
Pages: 175-180
Publication date: 19 Jul 2019

Host publication information

Title of host publication: Proceedings of the 2019 2nd International Conference on Data Science and Information Technology, DSIT 2019
Publisher: ACM
ISBN (Electronic): 9781450371414
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Data mining, Drilling stages, Real-time, Statistical analysis
Source: Scopus
Source ID: 85072810540

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

High-performance SIMD implementation of the lattice-Boltzmann method on the Xeon Phi processor

We present a high-performance implementation of the lattice-Boltzmann method (LBM) on the Knights Landing generation of Xeon Phi. The Knights Landing architecture includes 16GB of high-speed memory (MCDRAM) with a reported bandwidth of over 400 GB/s, and a subset of the AVX-512 single instruction multiple data (SIMD) instruction set. We explain five critical implementation aspects for high performance on this architecture: (1) the choice of appropriate LBM algorithm, (2) suitable data layout, (3) vectorization of the computation, (4) data prefetching, and (5) running our LBM simulations exclusively from the MCDRAM. The effects of these implementation aspects on the computational performance are demonstrated with the lattice-Boltzmann scheme involving the D3Q19 discrete velocity set and the TRT collision operator. In our benchmark simulations of fluid flow through porous media, using double-precision floating-point arithmetic, the observed performance exceeds 960 million fluid lattice site updates per second.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Physics, CSC - IT center for science, Abo Akad Univ, Abo Akademi University, Dept Phys, Jyväskylän yliopisto
Contributors: Robertsén, F., Mattila, K., Westerholm, J.
Number of pages: 16
Publication date: 10 Jul 2019
Peer-reviewed: Yes

Publication information

Journal: Concurrency Computation
Volume: 31
Issue number: 13
Article number: e5072
ISSN (Print): 1532-0626
Ratings: 
  • Scopus rating (2019): CiteScore 3.4 SJR 0.341 SNIP 0.944
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Computer Science Applications, Computer Networks and Communications, Computational Theory and Mathematics
Keywords: Lattice Boltzmann, prefetching, SIMD, Xeon Phi
Source: Scopus
Source ID: 85056764195

Research output: Contribution to journalArticleScientificpeer-review

Detection of Typical Pronunciation Errors in Non-native English Speech Using Convolutional Recurrent Neural Networks

A machine learning method for the automatic detection of pronunciation errors made by non-native speakers of English is proposed. It consists of training word-specific binary classifiers on a collected dataset of isolated words with possible pronunciation errors, typical for Finnish native speakers. The classifiers predict whether the typical error is present in the given word utterance. They operate on sequences of acoustic features, extracted from consecutive frames of an audio recording of a word utterance. The proposed architecture includes a convolutional neural network, a recurrent neural network, or a combination of the two. The optimal topology and hyperpa-rameters are obtained in a Bayesian optimisation setting using a tree-structured Parzen estimator. A dataset of 80 words uttered naturally by 120 speakers is collected. The performance of the proposed system, evaluated on a well-represented subset of the dataset, shows that it is capable of detecting pronunciation errors in most of the words (46/49) with high accuracy (mean accuracy gain over the zero rule 12.21 percent points).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Language Centre
Contributors: Diment, A., Fagerlund, E., Benfield, A., Virtanen, T.
Publication date: 1 Jul 2019

Host publication information

Title of host publication: 2019 International Joint Conference on Neural Networks, IJCNN 2019
Publisher: IEEE
ISBN (Electronic): 9781728119854
ASJC Scopus subject areas: Software, Artificial Intelligence
Keywords: Computer-assisted language learning, computer-assisted pronunciation training CNN, CRNN, GRU, pronunciation learning

Bibliographical note

jufoid=58177

Source: Scopus
Source ID: 85073198799

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

User Experience Study of 360° Music Videos on Computer Monitor and Virtual Reality Goggles

360° videos are increasingly used for media and entertainment, but the best practices for editing them are not yet well established. In this paper, we present a study in which we investigated the user experience of 360° music videos viewed on computer monitor and VR goggles. The research was conducted in the form of a laboratory experiment with 20 test participants. During the within-subject study, participants watched and evaluated four versions of the same 360° music video with a different cutting rate. Based on the results, an average cutting rate of 26 seconds delivered the highest-quality user experience both for computer monitor and VR goggles. The cutting rate matched with participants' mental models, and there was enough time to explore the environment without getting bored. Faster cutting rates made the users nervous, and a video consisting of a single shot was considered to be too static and boring.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Tampere University, Tampere University of Applied Sciences
Contributors: Holm, J., Väänänen, K., Remans, M. M. R.
Number of pages: 7
Pages: 81-87
Publication date: 1 Jul 2019

Host publication information

Title of host publication: Information Visualization - Biomedical Visualization and Geometric Modelling and Imaging, IV 2019
Publisher: IEEE
Editors: Banissi, E., Ursyn, A., McK. Bannatyne, M. W., Datia, N., Pires, J. M., Francese, R., Sarfraz, M., Wyeld, T. G., Bouali, F., Venturin, G., Azzag, H., Lebbah, M., Trutschl, M., Cvek, U., Muller, H., Nakayama, M., Kernbach, S., Caruccio, L., Risi, M., Erra, U., Vitiello, A., Rossano, V.
ISBN (Electronic): 9781728128382

Publication series

Name: Proceedings of the International Conference on Information Visualisation
ISSN (Print): 1093-9547
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition
Keywords: 360° video, cutting rate, hmd, music video, virtual reality, virtual reality goggles

Bibliographical note

jufoid=58079
EXT="Holm, Jukka"
INT=comp,"Remans, Mohammad Mushfiqur Rahman"

Source: Scopus
Source ID: 85072286445

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Public and open HEVC encoding service in the cloud

The ability to record vast amounts of video content requires convenient and efficient video coding services with which users can tackle the limited storage and transmission capacities. This paper presents an open-source cloud service for encoding raw video formats and transcoding compressed videos to the latest HEVC/H.265 format. Respective commercial transcoding services are available on the Internet but they are behind a paywall. On the other hand, using command-line interfaces of existing open-source software solutions requires in-depth knowledge of the coding process to attain the best coding gain and speed. The proposed service is available online, it is free to use without any registration, and its easy-to-use web interface makes it feasible for non-technical users. It is built on the FFmpeg multimedia framework whose built-in decoders accept various input video formats that are then compressed to HEVC with a full-fledged Kvazaar open-source encoder.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Tampere University
Contributors: Altonen, A., Viitanen, M., Räsänen, J., Mercat, A., Vanne, J.
Number of pages: 4
Pages: 300-303
Publication date: 18 Jun 2019

Host publication information

Title of host publication: Proceedings of the 10th ACM Multimedia Systems Conference, MMSys 2019
Publisher: ACM
ISBN (Electronic): 9781450362979
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Human-Computer Interaction, Software
Keywords: Cloud en/transcoding, FFmpeg, High efficiency video coding (HEVC), Kvazaar HEVC encoder, Software as a service (SaaS)

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Investigation of egocentric social structures for diversity-enhancing followee recommendations

The increasing amount of data in social media enables new advanced user modeling approaches. This paper focuses on user profiling for diversity-enhancing recommender systems for finding new followees on Twitter. By combining social network analysis with Latent Dirichlet Allocation based content analysis, we defined three egocentric structural positions on the network extracted from Twitter data: Mentions of Mentions, Community Cluster, Dormant Ties (and the rest as a baseline condition). In addition to describing the data analysis procedure, we report preliminary empirical findings on a user-centered evaluation study of recommendations based on the proposed matching strategy and the presented structural positions. The investigation of the possible overlaps of the groups and the participants' evaluations of perceived relevance of the recommendation imply that the three positions are sufficiently mutually exclusive and thus could serve as new diversity-enhancing mechanisms in various people recommender systems.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Information and Knowledge Management, Computing Sciences, Tampere University
Contributors: Skenderi, E., Olshannikova, E., Olsson, T., Huhtamäki, J., Koivunen, S., Yao, P., Huttunen, H.
Number of pages: 5
Pages: 257-261
Publication date: 6 Jun 2019

Host publication information

Title of host publication: ACM UMAP 2019 Adjunct - Adjunct Publication of the 27th Conference on User Modeling, Adaptation and Personalization
Publisher: ACM
ISBN (Electronic): 9781450367110
ASJC Scopus subject areas: Software
Keywords: Hybrid recommendation system, People recommender system, Social network analysis, Social recommender system, Twitter analytics, User modeling for social matching

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Facilitating the first move: Exploring inspirational design patterns for aiding initiation of social encounters

Actualizing positive social encounters remains both a key ends and means in many activities to foster a sense of community. Initiating encounters between strangers typically requires facilitative activities or artefacts, such as icebreakers or tickets-to-talk. However, there is little understanding of which designs are effective and why, and the broad design space remains largely underexplored. We address this challenge by presenting five candidates for inspirational design patterns on signaling social intentions and identifying impediments that deter commencement of encounters. The principles result from an extensive review of design cases and public art installations. Through focus groups and expert interviews, we assessed the perceived applicability and social acceptance of the proposed patterns. Three new design principles relating to the risks of initiating an encounter emerged through analyzing participant responses. These articulations of possible approaches and pitfalls for increasing conviviality may broaden the repertoire of, and support discussion between designers and others concerned with collocated social interaction.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, University of Southern Denmark
Contributors: Mitchell, R., Olsson, T.
Number of pages: 12
Pages: 283-294
Publication date: 3 Jun 2019

Host publication information

Title of host publication: C&T 2019 - 9th International Conference on Communities and Technologies, Conference Proceedings
Publisher: ACM
Editors: Tellioglu, H., Cech, F.
ISBN (Electronic): 9781450371629
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Collocated interaction, Design patterns, Social encounters, Social encouragement, Social interaction design, Ticket-to-talk
Source: Scopus
Source ID: 85067884637

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Towards Efficient Code Generation for Exposed Datapath Architectures

Coarse-grained reconfigurable architectures and other exposed datapath architectures such as transport-triggered architectures come with a high energy efficiency promise for accelerating data oriented workloads. Their main drawback results from the push of complexity from the architecture to the programmer; compiler techniques that allow starting from a higher-level programming language and generate code efficiently to such architectures robustly is still an open research area. In this article we survey the known main sources of challenges and outline a generic processor architecture template that covers the most common architecture variations along with a proposal for a common code generation framework for such challenging architectures.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Eindhoven University of Technology
Contributors: Vadivel, K., Jordans, R., Stujik, S., Corporaal, H., Jääskeläinen, P., Kultala, H.
Number of pages: 4
Pages: 86-89
Publication date: 27 May 2019

Host publication information

Title of host publication: Proceedings of the 22nd International Workshop on Software and Compilers for Embedded Systems, SCOPES 2019
Publisher: ACM
Editor: Stuijk, S.
ISBN (Electronic): 9781450367622
ASJC Scopus subject areas: Hardware and Architecture, Software
Keywords: CGRA, code generation, energy efficiency, reconfigurable architectures, scheduling, TTA
Source: Scopus
Source ID: 85066039585

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

1-D Convolutional Neural Networks for Signal Processing Applications

1D Convolutional Neural Networks (CNNs) have recently become the state-of-the-art technique for crucial signal processing applications such as patient-specific ECG classification, structural health monitoring, anomaly detection in power electronics circuitry and motor-fault detection. This is an expected outcome as there are numerous advantages of using an adaptive and compact 1D CNN instead of a conventional (2D) deep counterparts. First of all, compact 1D CNNs can be efficiently trained with a limited dataset of 1D signals while the 2D deep CNNs, besides requiring 1D to 2D data transformation, usually need datasets with massive size, e.g., in the »Big Data» scale in order to prevent the well-known »overfitting» problem. 1D CNNs can directly be applied to the raw signal (e.g., current, voltage, vibration, etc.) without requiring any pre- or post-processing such as feature extraction, selection, dimension reduction, denoising, etc. Furthermore, due to the simple and compact configuration of such adaptive 1D CNNs that perform only linear 1D convolutions (scalar multiplications and additions), a real-time and low-cost hardware implementation is feasible. This paper reviews the major signal processing applications of compact 1D CNNs with a brief theoretical background. We will present their state-of-the-art performances and conclude with focusing on some major properties. Keywords - 1-D CNNs, Biomedical Signal Processing, SHM.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research group: Multimedia Research Group - MRG, Qatar University, Electrical and Electronics Engineering Department, Izmir University of Economics
Contributors: Kiranyaz, S., Ince, T., Abdeljaber, O., Avci, O., Gabbouj, M.
Number of pages: 5
Pages: 8360-8364
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering

Bibliographical note

EXT="Kiranyaz, Serkan"
EXT="Ince, Turker"

Source: Scopus
Source ID: 85068995333

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Convex Energy Optimization of Streaming Applications for MPSoCs

The energy efficiency of modern MPSoCs is enhanced by complex hardware features such as Dynamic Voltage and Frequency Scaling (DVFS) and Dynamic Power Management (DPM). This paper introduces a new method, based on convex problem solving, that determines the most energy efficient operating point in terms of frequency and number of active cores in an MPSoC. The solution can challenge the popular approaches based on never-idle (or As-Slow-As-Possible (ASAP)) and race-to-idle (or As-Fast-As-Possible (AFAP)) principles. Experimental data are reported using a Samsung Exynos 5410 MPSoC and show a reduction in energy of up to 27 % when compared to ASAP and AFAP.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Universite de Rennes
Contributors: Nogues, E., Mercat, A., Arrestier, F., Pelcat, M., Menard, D.
Number of pages: 5
Pages: 1557-1561
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85068997223

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Deep Reinforcement Learning for Financial Trading Using Price Trailing

Developing accurate financial analysis tools can be useful both for speculative trading, as well as for analyzing the behavior of markets and promptly responding to unstable conditions ensuring the smooth operation of the financial markets. This led to the development of various methods for analyzing and forecasting the behaviour of financial assets, ranging from traditional quantitative finance to more modern machine learning approaches. However, the volatile and unstable behavior of financial markets forbids the accurate prediction of future prices, reducing the performance of these approaches. In contrast, in this paper we propose a novel price trailing method that goes beyond traditional price forecasting by reformulating trading as a control problem, effectively overcoming the aforementioned limitations. The proposed method leads to developing robust agents that can withstand large amounts of noise, while still capturing the price trends and allowing for taking profitable decisions.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Aristotle University of Thessaloniki, School of Informatics
Contributors: Zarkias, K. S., Passalis, N., Tsantekidis, A., Tefas, A.
Number of pages: 5
Pages: 3067-3071
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Deep Reinforcement Learning, Financial Markets, Price Forecasting, Trading

Bibliographical note

EXT="Tefas, Anastasios"

Source: Scopus
Source ID: 85068989312

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Deep Temporal Logistic Bag-of-features for Forecasting High Frequency Limit Order Book Time Series

Forecasting time series has several applications in various domains. The vast amount of data that are available nowadays provide the opportunity to use powerful deep learning approaches, but at the same time pose significant challenges of high-dimensionality, velocity and variety. In this paper, a novel logistic formulation of the well-known Bag-of-Features model is proposed to tackle these challenges. The proposed method is combined with deep convolutional feature extractors and is capable of accurately modeling the temporal behavior of time series, forming powerful forecasting models that can be trained in an end-to-end fashion. The proposed method was extensively evaluated using a large-scale financial time series dataset, that consists of more than 4 million limit orders, outperforming other competitive methods.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, School of Informatics, Aristotle University of Thessaloniki, Aarhus Universitet
Contributors: Passalis, N., Tefas, A., Kanniainen, J., Gabbouj, M., Iosifidis, A.
Number of pages: 5
Pages: 7545-7549
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Limit Order Book, Temporal Bag-of-Features, Time series forecasting

Bibliographical note

EXT="Tefas, Anastasios"
EXT="Iosifidis, Alexandros"

Source: Scopus
Source ID: 85069000578

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Low-latency Deep Clustering for Speech Separation

This paper proposes a low algorithmic latency adaptation of the deep clustering approach to speaker-independent speech separation. It consists of three parts: a) the usage of long-short-term-memory (LSTM) networks instead of their bidirectional variant used in the original work, b) using a short synthesis window (here 8 ms) required for low-latency operation, and, c) using a buffer in the beginning of audio mixture to estimate cluster centres corresponding to constituent speakers which are then utilized to separate speakers within the rest of the signal. The buffer duration would serve as an initialization phase after which the system is capable of operating with 8 ms algorithmic latency. We evaluate our proposed approach on two-speaker mixtures from Wall Street Journal (WSJ0) corpus. We observe that the use of LSTM yields around one dB lower SDR as compared to the baseline bidirectional LSTM in terms of source to distortion ratio (SDR). Moreover, using an 8 ms synthesis window instead of 32 ms degrades the separation performance by around 2.1 dB as compared to the baseline. Finally, we also report separation performance with different buffer durations noting that separation can be achieved even for buffer duration as low as 300 ms.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research group: Audio research group - ARG
Contributors: Wang, S., Naithani, G., Virtanen, T.
Number of pages: 5
Pages: 76-80
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Deep clustering, Low latency, Monaural speech separation

Bibliographical note

int=comp,"Wang, Shanshan"

Source: Scopus
Source ID: 85068960960

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Random Forest Oriented Fast QTBT Frame Partitioning

Block partition structure is a critical module in video coding scheme to achieve significant gap of compression performance. Under the exploration of future video coding standard by the Joint Video Exploration Team (JVET), named Versatile Video Coding (VVC), a new Quad Tree Binary Tree (QTBT) block partition structure has been introduced. In addition to the QT block partitioning defined by High Efficiency Video Coding (HEVC) standard, new horizontal and vertical BT partitions are enabled, which drastically increases the encoding time compared to HEVC. In this paper, we propose a fast QTBT partitioning scheme based on a Machine Learning approach. Complementary to techniques proposed in literature to reduce the complexity of HEVC Quad Tree (QT) partitioning, the propose solution uses Random Forest classifiers to determine for each block which partition modes between QT and BT is more likely to be selected. Using uncertainty zones of classifier decisions, the proposed complexity reduction technique is able to reduce in average by 30% the encoding time of JEM-v7.0 software in Random Access configuration with only 0.57% Bjontegaard Delta Rate (BD-BR) increase.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Universite de Rennes, MMP
Contributors: Amestoy, T., Mercat, A., Hamidouche, W., Bergeron, C., Menard, D.
Number of pages: 5
Pages: 1837-1841
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Complexity Reduction, JEM, Machine Learning, QTBT, Random Forest, Video Compression, VVC
Source: Scopus
Source ID: 85068966990

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Time Difference of Arrival Estimation of Speech Signals Using Deep Neural Networks with Integrated Time-frequency Masking

The Time Difference of Arrival (TDoA) of a sound wavefront impinging on a microphone pair carries spatial information about the source. However, captured speech typically contains dynamic non-speech interference sources and noise. Therefore, the TDoA estimates fluctuate between speech and interference. Deep Neural Networks (DNNs) have been applied for Time-Frequency (TF) masking for Acoustic Source Localization (ASL) to filter out non-speech components from a speaker location likelihood function. However, the type of TF mask for this task is not obvious. Secondly, the DNN should estimate the TDoA values, but existing solutions estimate the TF mask instead. To overcome these issues, a direct formulation of the TF masking as a part of a DNN-based ASL structure is proposed. Furthermore, the proposed network operates in an online manner, i.e., producing estimates frame-by-frame. Combined with the use of recurrent layers it exploits the sequential progression of speaker related TDoAs. Training with different microphone spacings allows model re-use for different microphone pair geometries in inference. Real-data experiments with smartphone recordings of speech in interference demonstrate the network's generalization capability.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Pertilä, P., Parviainen, M.
Number of pages: 5
Pages: 436-440
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Acoustic Source Localization, Microphone Arrays, Recurrent Neural Networks, Time-Frequency Masking
Electronic versions: 
Source: Scopus
Source ID: 85068957469

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Variance Preserving Initialization for Training Deep Neuromorphic Photonic Networks with Sinusoidal Activations

Photonic neuromorphic hardware can provide significant performance benefits for Deep Learning (DL) applications by accelerating and reducing the energy requirements of DL models. However, photonic neuromorphic architectures employ different activation elements than those traditionally used in DL, slowing down the convergence of the training process for such architectures. An initialization scheme that can be used to efficiently train deep photonic networks that employ quadratic sinusoidal activation functions is proposed in this paper. The proposed initialization scheme can overcome these limitations, leading to faster and more stable training of deep photonic neural networks. The ability of the proposed method to improve the convergence of the training process is experimentally demonstrated using two different DL architectures and two datasets.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Aristotle University of Thessaloniki
Contributors: Passalis, N., Mourgias-Alexandris, G., Tsakyridis, A., Pleros, N., Tefas, A.
Number of pages: 5
Pages: 1483-1487
Publication date: 1 May 2019

Host publication information

Title of host publication: 2019 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2019 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781479981311
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Neuromorphic Hardware, Photonic Neural Networks, Sinusoidal Activations

Bibliographical note

EXT="Tefas, Anastasios"

Source: Scopus
Source ID: 85064389224

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

The FitOptiVis ECSEL Project: Highly Efficient Distributed Embedded Image/Video Processing in Cyber-Physical Systems Invited Pape

Cyber-Physical Systems (CPS) are systems that are in feedback with their environment, possibly with humans in the loop. They are often distributed with sensors and actuators, smart, adaptive and predictive and react in real-time. Image- A nd video-processing pipelines are a prime source for environmental information improving the possibilities of active, relevant feedback. In such a context, FitOptiVis aims to provide end-to-end multi-objective optimization for imaging and video pipelines of CPS, with emphasis on energy and performance, leveraging on a reference architecture, supported by low-power, high-performance, smart devices, and by methods and tools for combined design-time and run-time multi-objective optimization within system and environment constraints.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Delft University of Technology, Eindhoven University of Technology, Royal Philips, Institute of Information Theory and Automation of the Academy of Sciences of the Czech Republic, Thales Alenia Space Italia, PolComIng - Information Engineering Unit, Università dell'Aquila, Nokia Technologies, Turku University of Applied Science, Dept. of Electrical and Electronic Engineering, Abinsula
Contributors: Al-Ars, Z., Basten, T., Beer, A., Geilen, M., Goswami, D., Jääskeläinen, P., Kadlec, J., Alejandro, M. M., Palumbo, F., Peeren, G., Pomante, L., Linden, F. V., Saarinen, J., Säntti, T., Sau, C., Zedda, M. K.
Number of pages: 6
Pages: 333-338
Publication date: 30 Apr 2019

Host publication information

Title of host publication: ACM International Conference on Computing Frontiers 2019, CF 2019 - Proceedings
Publisher: ACM
ISBN (Electronic): 9781450366854
ASJC Scopus subject areas: Software
Keywords: Distributed systems, Energy and performance optimization, Heterogeneous system, Image-video processing
Source: Scopus
Source ID: 85066051362

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

How do academics experience use of recorded audio feedback in higher education? A thematic analysis

Our Work in Progress Paper in Research to Practice Category focuses on use of recorded audio feedback (RAF) in higher education. RAF is one method for providing feedback that is becoming increasingly popular, especially in e-education. According to previous studies, most learners have an overall positive attitude towards RAF. However, many of the studies have been carried out from learners' point of view. To complement RAF research, we study how academics experience use of RAF as a feedback method. We adopted a qualitative content analysis approach, applying thematic network analysis to the data received from four case academics. This approach proposes graphical networks as an aid for analyzing and synthesizing qualitative data into basic, organizing and global themes. The thematic network analysis produced two global, nine organizational and 45 basic themes. The two global themes were named 'Dialogue diversification' and 'Load reduction'. Based on our analysis, academics can, by using RAF, provide learners more relaxed and dialogic feedback and reduce their own workload both mentally and physically.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Jyväskylän yliopisto
Contributors: Heimbirger, A., Isomottonen, V., Nieminen, P., Keto, H.
Publication date: 4 Mar 2019

Host publication information

Title of host publication: Frontiers in Education : Fostering Innovation Through Diversity, FIE 2018 - Conference Proceedings
Publisher: IEEE
Article number: 8658635
ISBN (Electronic): 9781538611739

Publication series

Name: Proceedings - Frontiers in Education Conference
ISSN (Print): 1539-4565
ASJC Scopus subject areas: Software, Education, Computer Science Applications
Keywords: Academics, Distance learning, E-education, Higher education, RAF, Recorded audio feedback, Thematic network analysis, Work in Progress

Bibliographical note

jufoid=70484

Source: Scopus
Source ID: 85063507477

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Challenges of Multi-Factor Authentication for Securing Advanced IoT Applications

The unprecedented proliferation of smart devices together with novel communication, computing, and control technologies have paved the way for A-IoT. This development involves new categories of capable devices, such as high-end wearables, smart vehicles, and consumer drones aiming to enable efficient and collaborative utilization within the smart city paradigm. While massive deployments of these objects may enrich people's lives, unauthorized access to said equipment is potentially dangerous. Hence, highly secure human authentication mechanisms have to be designed. At the same time, human beings desire comfortable interaction with the devices they own on a daily basis, thus demanding authentication procedures to be seamless and user-friendly, mindful of contemporary urban dynamics. In response to these unique challenges, this work advocates for the adoption of multi-factor authentication for A-IoT, such that multiple heterogeneous methods - both well established and emerging - are combined intelligently to grant or deny access reliably. We thus discuss the pros and cons of various solutions as well as introduce tools to combine the authentication factors, with an emphasis on challenging smart city environments. We finally outline the open questions to shape future research efforts in this emerging field.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, National Research University Higher School of Economics, ITMO University, Electrical Engineering Department, University of California, Los Angeles (UCLA)
Contributors: Ometov, A., Petrov, V., Bezzateev, S., Andreev, S., Koucheryavy, Y., Gerla, M.
Number of pages: 7
Pages: 82-88
Publication date: 1 Mar 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Network
Volume: 33
Issue number: 2
ISSN (Print): 0890-8044
Ratings: 
  • Scopus rating (2019): CiteScore 21.6 SJR 2.773 SNIP 3.323
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Hardware and Architecture, Computer Networks and Communications
Source: Scopus
Source ID: 85063775257

Research output: Contribution to journalArticleScientificpeer-review

Analysis of an efficient parallel implementation of active-set Newton algorithm

This paper presents an analysis of an efficient parallel implementation of the active-set Newton algorithm (ASNA), which is used to estimate the nonnegative weights of linear combinations of the atoms in a large-scale dictionary to approximate an observation vector by minimizing the Kullback–Leibler divergence between the observation vector and the approximation. The performance of ASNA has been proved in previous works against other state-of-the-art methods. The implementations analysed in this paper have been developed in C, using parallel programming techniques to obtain a better performance in multicore architectures than the original MATLAB implementation. Also a hardware analysis is performed to check the influence of CPU frequency and number of CPU cores in the different implementations proposed. The new implementations allow ASNA algorithm to tackle real-time problems due to the execution time reduction obtained.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Audio research group - ARG, Universitat Politècnica de València
Contributors: San Juan Sebastián, P., Virtanen, T., Garcia-Molla, V. M., Vidal, A. M.
Number of pages: 12
Pages: 1298-1309
Publication date: Mar 2019
Peer-reviewed: Yes
Early online date: 19 May 2018

Publication information

Journal: Journal of Supercomputing
Volume: 75
Issue number: 3
ISSN (Print): 0920-8542
Ratings: 
  • Scopus rating (2019): CiteScore 3.9 SJR 0.432 SNIP 1.181
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Information Systems, Hardware and Architecture
Keywords: Convex optimization, Multicore, Newton algorithm, Parallel computing, Sparse representation
Source: Scopus
Source ID: 85047129085

Research output: Contribution to journalArticleScientificpeer-review

Convolutional low-resolution fine-grained classification

Successful fine-grained image classification methods learn subtle details between visually similar (sub-)classes, but the problem becomes significantly more challenging if the details are missing due to low resolution. Encouraged by the recent success of Convolutional Neural Network (CNN) architectures in image classification, we propose a novel resolution-aware deep model which combines convolutional image super-resolution and convolutional fine-grained classification into a single model in an end-to-end manner. Extensive experiments on multiple benchmarks demonstrate that the proposed model consistently performs better than conventional convolutional networks on classifying fine-grained object classes in low-resolution images.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Vision
Contributors: Cai, D., Chen, K., Qian, Y., Kämäräinen, J.
Pages: 166-171
Publication date: Mar 2019
Peer-reviewed: Yes
Early online date: 2017

Publication information

Journal: Pattern Recognition Letters
Volume: 119
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2019): CiteScore 6.3 SJR 0.848 SNIP 2.021
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
Keywords: Deep learning, Fine-grained image classification, Super resolution convoluational neural networks
Source: Scopus
Source ID: 85032974725

Research output: Contribution to journalArticleScientificpeer-review

Challenges and recommended practices for software architecting in global software development

Context: Global software development (GSD), although now a norm in the software industry, carries with it enormous challenges mostly regarding communication and coordination. Aforementioned challenges are highlighted when there is a need to transfer knowledge between sites, particularly when software artifacts assigned to different sites depend on each other. The design of the software architecture and associated task dependencies play a major role in reducing some of these challenges. Objective: The current literature does not provide a cohesive picture of how the distributed nature of software development is taken into account during the design phase: what to avoid, and what works in practice. The objective of this paper is to gain an understanding of software architecting in the context of GSD, in order to develop a framework of challenges and solutions that can be applied in both research and practice. Method: We conducted a systematic literature review (SLR) that synthesises (i) challenges which GSD imposes on software architecture design, and (ii) recommended practices to alleviate these challenges. Results: We produced a comprehensive set of guidelines for performing software architecture design in GSD based on 55 selected studies. Our framework comprises nine key challenges with 28 related concerns, and nine recommended practices, with 22 related concerns for software architecture design in GSD. These challenges and practices were mapped to a thematic conceptual model with the following concepts: Organization (Structure and Resources), Ways of Working (Architecture Knowledge Management, Change Management and Quality Management), Design Practices, Modularity and Task Allocation. Conclusion: The synthesis of findings resulted in a thematic conceptual model of the problem area, a mapping of the key challenges to practices, and a concern framework providing concrete questions to aid the design process in a distributed setting. This is a first step in creating more concrete architecture design practices and guidelines.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Research area: Software engineering, University of Limerick
Contributors: Sievi-Korte, O., Beecham, S., Richardson, I.
Number of pages: 20
Pages: 234-253
Publication date: 1 Feb 2019
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: Information and Software Technology
Volume: 106
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2019): CiteScore 7.6 SJR 0.781 SNIP 2.555
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Design practice, Global software development, Software architecture, Software design, Systematic literature review
URLs: 
Source: Scopus
Source ID: 85055646041

Research output: Contribution to journalArticleScientificpeer-review

Additional lossless compression of JPEG images based on BPG

The task of additional lossless compression of JPEG images is considered. We propose to decode JPEG image and recompress it using lossy BPG (Better Portable Graphics) codec based on a subset of the HEVC open video compression standard. Then the decompressed and smoothed BPG image is used for calculation and quantization of DCT coefficients in 8x8 image blocks using quantization tables of the source JPEG image. A difference between obtained quantized DCT coefficients and quantized DCT coefficients of the source JPEG image (prediction error) is calculated. The difference is lossless compressed by a proposed context modeling and arithmetical coding. In this way the source JPEG image is replaced by two files: compressed BPG image and the compressed difference which needed for lossless restoration of the source JPEG image. It is shown that the proposed approach provides compression ratios comparable with state of the art PAQ8, WinZip and STUFFIT file archivers. At the same time BPG images may be used for fast preview of compressed JPEG images.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Kharkiv National Aerospace University
Contributors: Ponomarenko, M., Miroshnichenko, O., Lukin, V., Egiazarian, K.
Publication date: 13 Jan 2019

Host publication information

Title of host publication: Image Processing: Algorithms and Systems XVII

Publication series

Name: IS and T International Symposium on Electronic Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Context modelling, Discrete cosine transform, JPEG, JPEG additional compression
Source: Scopus
Source ID: 85080092000

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Combined no-reference IQA metric and its performance analysis

The problem of increasing efficiency of blind image quality assessment is considered. No-reference image quality metrics both independently and as components of complex image processing systems are employed in various application areas where images are the main carriers of information. Meanwhile, existing no-reference metrics have a significant drawback characterized by a low adequacy to image perception by human visual system (HVS). Many well-known no-reference metrics are analyzed in our paper for several image databases. A method of combining several no-reference metrics based on artificial neural networks is proposed based on multi-database verification approach. The effectiveness of the proposed approach is confirmed by extensive experiments.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Kharkiv National Aerospace University
Contributors: Ieremeiev, O., Lukin, V., Ponomarenko, N., Egiazarian, K.
Publication date: 13 Jan 2019

Host publication information

Title of host publication: Image Processing: Algorithms and Systems XVII

Publication series

Name: IS and T International Symposium on Electronic Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Combined metrics, Full-reference metrics, Image visual quality assessment, Robust metrics
Source: Scopus
Source ID: 85080028392

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Phase masks optimization for broadband diffractive imaging

The task of optimization of phase masks for broadband diffractive imaging to minimize chromatic aberrations and to provide given value of Depth of Focus (DoF) is considered. Different schemes of multilevel phase mask (MPM) forming by combining pixels of two Fresnel lenses are analyzed. The Fresnel lenses are calculated for the same focal distance but for very different wavelengths. A possibility of adding to the optimized mask a cubic component is taking into account as well as usage of discrete phase masks with optimized number of levels. It is shown that the proposed approach in the combination with inverse imaging allows to significantly increase image quality for a focus distance in comparison to refractive lens-based optical systems. Moreover, it is shown that by changing of aforementioned parameters it is possible to increase or decrease DoF value depending from a given goal of optimization. It is demonstrated by numerical analysis that the proposed approach significantly increases robustness of designed MPM to Gaussian additive noise in MPM introduced due to fabrication errors.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, Research group: Computational Imaging-CI
Contributors: Ponomarenko, M., Katkovnik, V., Egiazarian, K.
Publication date: 13 Jan 2019

Host publication information

Title of host publication: Image Processing: Algorithms and Systems XVII

Publication series

Name: IS and T International Symposium on Electronic Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Diffractive optical elements, Inverse imaging, Lensless imaging, Multilevel phase mask design
Source: Scopus
Source ID: 85080039777

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Thin form-factor super multiview head-up display system

We propose a virtual-image head-up display (HUD) based on the super multiview (SMV) display technology. Implementation-wise, the HUD provides a compact solution, consisting of a thin form-factor SMV display and a combiner placed on the windshield of the vehicle. Since the utilized display is at most few centimeters thick, it does not need extra installation space that is usually required by most of the existing virtual image HUDs. We analyze the capabilities of the proposed system in terms of several HUD related quality factors such as resolution, eyebox width, and target image depth. Subsequently, we verify the analysis results through experiments carried out using our SMV-HUD demonstrator. We show that the proposed system is capable of visualizing images at the typical virtual image HUD depths of 2 − 3m, in a reasonably large eyebox, which is slightly over 30cm in our demonstrator. For an image at the target virtual image depth of 2.5m, the field of view of the developed system is 11x16 and the spatial resolution is around 240x60 pixels in vertical and horizontal directions, respectively. There is, however, plenty of room for improvement regarding the resolution, as we actually utilize an LCD at moderate resolution (216 ppi) and off-the-shelf lenticular sheet in our demonstrator.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Akpinar, U., Sahin, E., Suominen, O., Gotchev, A.
Publication date: 13 Jan 2019

Host publication information

Title of host publication: Stereoscopic Displays and Applications XXX

Publication series

Name:  IS&T International Symposium on Electronic Imaging
ISSN (Electronic): 2470-1173
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics

Bibliographical note

jufoid=84313

Source: Scopus
Source ID: 85081086336

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Performance evaluation of bandwidth reservation for mmWave 5G NR systems

Introduction: In 3GPP New Radio (NR) systems, frequent radio propagation path blockages can lead to the disconnection of ongoing sessions already accepted into the system, reducing the quality of service in the network. Controlling access to system resource by prioritizing for the ongoing sessions can increase the session continuity. In this paper, we propose resource allocation with a reservation mechanism. Purpose: Development of a mathematical model for analyzing the effect of this mechanism on other system performance indicators - dropping probabilities for new and ongoing sessions and system utilization. The model takes into account the key features of the 3GPP NR technology, including the height of the interacting objects, the spatial distribution and mobility of the blockers, as well as the line-of-sight propagation properties between the transceivers for mmWave NR technology. Results: We analyzed the reservation mechanism with the help of a developed model in the form of a resource queueing system with signals, where the base station bandwidth corresponds to the resource, and the signals model a change in the line-of-sight conditions between the receiving and transmitting devices. Creating a priority for ongoing sessions whose service has not yet been completed provides a considerable flexibility for balancing the session continuity and dropping of a new session, with a slight decrease in the efficiency of the radio resource utility. With the developed model, we showed that reserving even a small bandwidth (less than 10% of the total resources) to maintain the ongoing sessions has a positive effect on their continuity, as it increases the probability of their successful completion. Practical relevance: The proposed mechanism works more efficiently in overload conditions and with sessions which have a high data transfer rate requirements. This increases the demand for the proposed mechanism in 5G NR communication systems.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Peoples’ Friendship University of Russia, Federal Research Center Computer Science and Control of the Russian Academy of Sciences
Contributors: Begishev, V. O., Sopin, E. S., Molchanov, D. A., Samouylov, A. K., Gaidamaka, Y. V., Samouylov, K. E.
Number of pages: 13
Pages: 51-63
Publication date: 1 Jan 2019
Peer-reviewed: Yes

Publication information

Journal: Informatsionno-Upravliaiushchie Sistemy
Issue number: 5
ISSN (Print): 1684-8853
Ratings: 
  • Scopus rating (2019): CiteScore 0.5 SJR 0.201 SNIP 0.507
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Information Systems, Human-Computer Interaction, Computer Science Applications, Control and Optimization
Keywords: 5G networks, Bandwidth reservation, Millimeter wave, New Radio, New session drop probability, Ongoing session drop probability, Session continuity, System resource utilization
Source: Scopus
Source ID: 85082424315

Research output: Contribution to journalArticleScientificpeer-review

Towards detecting structural branching and cyclicity in graphs: A polynomial-based approach

Structural properties of graphs and networks have been investigated across scientific disciplines ranging from mathematics to structural chemistry. Structural branching, cyclicity and, more generally, connectedness are well-known examples of such properties. In particular, various graph measures for detecting structural branching and cyclicity have been investigated. These measures are of limited applicability since their interpretation relies heavily on a certain definition of structural branching. In this paper we define a related measure, taking an approach to measurement similar to that of Lovász and Pelikán (On the eigenvalues of trees, Periodica Mathematica Hungarica, Vol. 3 (1–2), 1973, 175–182). We define a complex valued polynomial which also has a unique positive root. Analytical and numerical results demonstrate that this measure can be interpreted as a structural branching and cyclicity measure for graphs. Our results generalize the work of Lovász and Pelikán since the measure we introduce is not restricted to trees.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Computational Medicine and Statistical Learning Laboratory (CMSL), Research group: Predictive Society and Data Analytics (PSDA), University of Applied Sciences Upper Austria, Nankai University, Hall in Tyrol, The City College of New York (CUNY), Shandong University at Weihai
Contributors: Dehmer, M., Chen, Z., Emmert-Streib, F., Mowshowitz, A., Shi, Y., Tripathi, S., Zhang, Y.
Number of pages: 10
Pages: 19-28
Publication date: 1 Jan 2019
Peer-reviewed: Yes
Early online date: 29 Aug 2018

Publication information

Journal: Information Sciences
Volume: 471
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2019): CiteScore 11.3 SJR 1.723 SNIP 2.688
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Data science, Graphs, Networks, Quantitative graph theory, Structural branching
Source: Scopus
Source ID: 85052883508

Research output: Contribution to journalArticleScientificpeer-review

Business intelligence process model revisited

Today many organizations have come to value knowledge as a production factor. Thus, there is a constant need for getting the information in and sorted. Business intelligence (BI) is a process for systematic acquiring, analyzing, and disseminating data and information from various sources to gain understanding about the business's environment. This is required for supporting decisions for achieving organization's business objectives. Literature has introduced models for planning and executing BI. However, as business environments and technologies evolve in a rapid pace, are the models still applicable? Not all recent issues are taken into consideration in the previous models. BI is considered to be integrated into business processes, so the similar evolution is expected to take place. There are two studies investigating BI instigating this study, but there are still questions to be answered. Literature on different models and findings of these studies were combined to form a vision to better match reality. Various issues like users' active involvement, real-time analysis and presentation, and social media resources were brought up. Practitioners can use the approach to assess their current state of BI activities or planning the organization of BI program.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Information and Knowledge Management
Contributors: Hellsten, P., Myllärniemi, J.
Number of pages: 8
Pages: 341-348
Publication date: 2019

Host publication information

Title of host publication: IC3K 2019 - Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management
Publisher: SCITEPRESS
Editors: Bernardino, J., Salgado, A., Filipe, J.
ISBN (Electronic): 9789897583827

Publication series

Name: IC3K 2019 - Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management
Volume: 3
ASJC Scopus subject areas: Software
Keywords: Business Intelligence, Business Intelligence Process Model, Decision-Making, Organizational Development

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Challenges in developing data-based value creation

Understanding data-based value creation helps organizations to enhance its decision-making and to renew their business operations. However, organizations aiming to use modern data analytics face several severe challenges that are not usually so evident or visible beforehand. In this paper we study a Finnish manufacturing company's data empowerment and information and knowledge management practices in order to identify the potential challenges related to modern data-based value creation within industrial context. The empirical data is consisted of group discussions, relevant data sets acquired from the case company's information systems, and lastly, 12 thematic interviews of the key actors in the company in relation to service development. The study provides valuable insights for managing service development and decision-making and creates understanding on data-based value creation. Achieved understanding provides meaningful knowledge for organizations utilizing or having plans to utilize, for example, data analytic methods in their businesses.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Information and Knowledge Management
Contributors: Myllärniemi, J., Helander, N., Pekkola, S.
Number of pages: 7
Pages: 370-376
Publication date: 2019

Host publication information

Title of host publication: IC3K 2019 - Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management
Publisher: SCITEPRESS
Editors: Bernardino, J., Salgado, A., Filipe, J.
ISBN (Electronic): 9789897583827

Publication series

Name: IC3K 2019 - Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management
Volume: 3
ASJC Scopus subject areas: Software
Keywords: Case Study, Data-based Value Creation, Information Management Process, Knowledge Management

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Co-creating digital services for citizens: Activity theory analysis

Smart city development relies heavily on creation of digital services that are available for the citizens and for the city authorities. At best, these services are co-created by the authorities, citizens and the digital solution supplier companies. Digital service co-creation is, however, a complex process and includes several contradictions due to presence of several stakeholders. In this paper, we present a case study of smart city initiated digital service co-creation process through the analytical lenses of activity theory.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Information and Knowledge Management, HAMK Design Factory, HAMK University of Applied Sciences, HAMK Smart Research Unit
Contributors: Jussila, J., Kukkamäki, J., Helander, N.
Number of pages: 6
Pages: 285-290
Publication date: 2019

Host publication information

Title of host publication: IC3K 2019 - Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management
Publisher: SCITEPRESS
Editors: Bernardino, J., Salgado, A., Filipe, J.
ISBN (Electronic): 9789897583827

Publication series

Name: IC3K 2019 - Proceedings of the 11th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management
Volume: 3
ASJC Scopus subject areas: Software
Keywords: Activity Theory, Co-creation, Digital Service, Empirical Study

Bibliographical note

EXT="Jussila, Jari"

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Compatible natural gradient policy search

Trust-region methods have yielded state-of-the-art results in policy search. A common approach is to use KL-divergence to bound the region of trust resulting in a natural gradient policy update. We show that the natural gradient and trust region optimization are equivalent if we use the natural parameterization of a standard exponential policy distribution in combination with compatible value function approximation. Moreover, we show that standard natural gradient updates may reduce the entropy of the policy according to a wrong schedule leading to premature convergence. To control entropy reduction we introduce a new policy search method called compatible policy search (COPOS) which bounds entropy loss. The experimental results show that COPOS yields state-of-the-art results in challenging continuous control tasks and in discrete partially observable tasks.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Intelligent Autonomous Systems, Technical University Darmstadt, MPI for Intelligent Systems, University of Lincoln
Contributors: Pajarinen, J., Thai, H. L., Akrour, R., Peters, J., Neumann, G.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Machine Learning
ISSN (Print): 0885-6125
Ratings: 
  • Scopus rating (2019): CiteScore 5 SJR 1.034 SNIP 1.941
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence
Keywords: Policy search, Reinforcement learning
Electronic versions: 
Source: Scopus
Source ID: 85066145275

Research output: Contribution to journalArticleScientificpeer-review

Continuum approach to high-cycle fatigue. The finite life-time case with stochastic stress history

In this paper, we consider continuum approach for high-cycle fatigue in the case where life-time is finite. The method is based on differential equations and all basic concepts are explained. A stress history is assumed to be a stochastic process and this leads us to the theory of stochastic differential equations. The life-time is a quantity, which tells us when the breakdown of the material happens. In this method, it is naturally a random variable. The basic assumption is, that the distribution of the life-time is log-normal or Weibull. We give a numerical basic example to demonstrate the method.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences
Contributors: Orelma, H.
Number of pages: 12
Pages: 452-463
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Vestnik Samarskogo Gosudarstvennogo Tekhnicheskogo Universiteta, Seriya Fiziko-Matematicheskie Nauki
Volume: 23
Issue number: 3
ISSN (Print): 1991-8615
Ratings: 
  • Scopus rating (2019): CiteScore 0
Original language: English
ASJC Scopus subject areas: Mechanics of Materials, Condensed Matter Physics, Mathematical Physics, Modelling and Simulation, Analysis, Applied Mathematics, Software
Keywords: Evolution equation, High-cycle fatigue, Life-time
Source: Scopus
Source ID: 85079143163

Research output: Contribution to journalArticleScientificpeer-review

Farm detection based on deep convolutional neural nets and semi-supervised green texture detection using VIS-NIR satellite image

Farm detection using low resolution satellite images is an important topic in digital agriculture. However, it has not received enough attention compared to high-resolution images. Although high resolution images are more efficient for detection of land cover components, the analysis of low-resolution images are yet important due to the low-resolution repositories of the past satellite images used for timeseries analysis, free availability and economic concerns. The current paper addresses the problem of farm detection using low resolution satellite images. In digital agriculture, farm detection has significant role for key applications such as crop yield monitoring. Two main categories of object detection strategies are studied and compared in this paper; First, a two-step semi-supervised methodology is developed using traditional manual feature extraction and modelling techniques; the developed methodology uses the Normalized Difference Moisture Index (NDMI), Grey Level Co-occurrence Matrix (GLCM), 2-D Discrete Cosine Transform (DCT) and morphological features and Support Vector Machine (SVM) for classifier modelling. In the second strategy, high-level features learnt from the massive filter banks of deep Convolutional Neural Networks (CNNs) are utilised. Transfer learning strategies are employed for pretrained Visual Geometry Group Network (VGG-16) networks. Results show the superiority of the high-level features for classification of farm regions.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Electrical Engineering, Coventry University
Contributors: Sharifzadeh, S., Tata, J., Tan, B.
Number of pages: 9
Pages: 100-108
Publication date: 2019

Host publication information

Title of host publication: DATA 2019 - Proceedings of the 8th International Conference on Data Science, Technology and Applications
Publisher: SCITEPRESS
Editors: Hammoudi, S., Quix, C., Bernardino, J.
ISBN (Electronic): 9789897583773
ASJC Scopus subject areas: Hardware and Architecture, Information Systems, Software, Computer Networks and Communications
Keywords: Classification, Convolutional Neural Nets (CNNs), Digital Agriculture, Satellite Image, Supervised Feature Extraction
Electronic versions: 

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Institutional Perspectives on the Process of Enterprise Architecture Adoption

Organizations often adopt enterprise architecture (EA) when planning how best to develop their information technology (IT) or businesses, for strategic management, or generally for managing change initiatives. This variety of different uses affects many stakeholders within and between organizations. Because stakeholders have dissimilar backgrounds, positions, assumptions, and activities, they respond differently to changes and the potential problems that emerge from those changes. This situation creates contradictions and conflicts between stakeholders that may further influence project activities and ultimately determine how EA is adopted. In this paper, we examine how institutional pressures influence EA adoption. Based on a qualitative case study of two cases, we show how regulative, normative, and cognitive pressures influence stakeholders’ activities and behaviors during the process of EA adoption. Our contribution thus lies in identifying roles of institutional pressures in different phases during the process of EA adoption and how it changes overtime. The results provide insights into EA adoption and the process of institutionalization, which help to explain emergent challenges in EA adoption.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Information and Knowledge Management, Research group: Business Data Research Group, University of Vaasa (UVA)
Contributors: Dang, D., Pekkola, S.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Information Systems Frontiers
ISSN (Print): 1387-3326
Ratings: 
  • Scopus rating (2019): CiteScore 6.7 SJR 1.02 SNIP 1.926
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Information Systems, Computer Networks and Communications
Keywords: EA adoption, Enterprise architecture, Institutional theory, Institutionalization process

Bibliographical note

EXT="Dang, Duong"

Source: Scopus
Source ID: 85069739091

Research output: Contribution to journalArticleScientificpeer-review

Log analysis of 360-degree video users via MQTT

Analyzing 360-degree video users is beneficial for 360-degree video application development. The analysis can be done with logged user data. In this paper, we argue that MQTT is a conventional technology for distributed logging of mobile 360-degree video users. MQTT not only saves resources also allows communication from the logging server to mobile clients in various networking conditions relatively easy. We constructed a proof of concept to show the feasibility of the approach. As log analysis examples, the proof of concept visualizes results of the most popular region of interest analysis and k-means clustering. The used research method is design science.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Luoto, A.
Number of pages: 8
Pages: 130-137
Publication date: 2019

Host publication information

Title of host publication: ICGDA 2019 : Proceedings of the 2019 2nd International Conference on Geoinformatics and Data Analysis
Publisher: ACM
ISBN (Electronic): 978-1-4503-6245-0
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: 360-degree video, Component, Log Analysis, MQTT
Electronic versions: 
Source: Scopus
Source ID: 85066837109

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

PyGOP: A Python library for Generalized Operational Perceptron algorithms

PyGOP provides a reference implementation of existing algorithms using Generalized Operational Perceptron (GOP), a recently proposed artificial neuron model. The implementation adopts a user-friendly interface while allowing a high level of customization including user-defined operators, custom loss function, custom metric functions that requires full batch evaluation such as Precision, Recall or F1. Besides, PyGOP supports different computation environments (CPU/GPU) on both single machine and cluster using SLURM job scheduler. In addition, since training GOP-based algorithms might take days, PyGOP automatically saves checkpoints during computation and allows resuming to the last checkpoint in case the script got interfered in the middle during the progression.

General information

Publication status: Accepted/In press
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Qatar University, Aarhus Universitet
Contributors: Tran, D. T., Kiranyaz, S., Gabbouj, M., Iosifidis, A.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Knowledge-Based Systems
ISSN (Print): 0950-7051
Ratings: 
  • Scopus rating (2019): CiteScore 11.7 SJR 1.754 SNIP 2.902
Original language: English
ASJC Scopus subject areas: Software, Management Information Systems, Information Systems and Management, Artificial Intelligence
Keywords: Generalized Operational Perceptron (GOP), Heterogeneous Multilayer Generalized Operational Perceptron (HeMLGOP), Progressive Operational Perceptron (POP), Progressive Operational Perceptron with Memory (POPmem)

Bibliographical note

EXT="Kiranyaz, Serkan"
EXT="Iosifidis, Alexandros"

Source: Scopus
Source ID: 85066982487

Research output: Contribution to journalArticleScientificpeer-review

Revisiting continuous deployment maturity: A two-year perspective

Background: Achieving a steady stream of small releases and employing practices such as continuous deployment requires maturity in company processes. Maturity models provide one approach for companies to pinpoint areas of improvement by providing a position and hints to reflect on. Incorporating maturity models with agile software development and continuous deployment has its challenges, though. Aims: The focus of the study is in understanding the evolution of software processes towards continuous deployment in an industry organization over time when a maturity model is used as a yardstick in evaluation. Method: An embedded case study by design, the study utilizes and replicates a survey on the state of software projects in a large Finnish software company, Solita. The survey was initially conducted in 2015 with responses from 35 projects and now replicated in 2017 with responses from 43 projects. Both quantitative and qualitative approaches for survey responses are used in the analysis. Results: Maturity of software processes in the case company show improvement in deployment and in monitoring, albeit short of statistical significance. Technological advances in the application of cloud computing have likely spurred development in these areas. Capability in processes related to test automation and quality has not changed much in two years. Conclusions: Maintaining maturity in software processes requires constant attention as impressions on process quality can gradually diminish. Projects which are built on a compatible technology stack have a greater chance in achieving continuous deployment and thus being more mature. Customer preferences also make a difference in the ability to reach certain maturity levels.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences, University of Helsinki, Solita Plc.
Contributors: Mäkinen, S., Puonti, M., Lehtonen, T., Mikkonen, T., Kilamo, T., Männistö, T.
Number of pages: 8
Pages: 1810-1817
Publication date: 2019

Host publication information

Title of host publication: Proceedings of the 34th ACM/SIGAPP Symposium on Applied Computing
Publisher: ACM
ISBN (Print): 9781450359337
ASJC Scopus subject areas: Software

Bibliographical note

EXT="Mikkonen, Tommi"
EXT="Puonti, Mikko"

Source: Scopus
Source ID: 85065664245

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

The Lord of the shares: Combining attribute-based encryption and searchable encryption for flexible data sharing

Secure cloud storage is considered one of the most important issues that both businesses and end-users are considering before moving their private data to the cloud. Lately, we have seen some interesting approaches that are based either on the promising concept of Symmetric Searchable Encryption (SSE) or on the well-studied field of Attribute-Based Encryption (ABE). In the first case, researchers are trying to design protocols where users' data will be protected from both internal and external attacks without paying the necessary attention to the problem of user revocation. On the other hand, in the second case existing approaches address the problem of revocation. However, the overall efficiency of these systems is compromised since the proposed protocols are solely based on ABE schemes and the size of the produced ciphertexts and the time required to decrypt grows with the complexity of the access formula. In this paper, we propose a protocol that combines both SSE and ABE in a way that the main advantages of each scheme are used. The proposed protocol allows users to directly search over encrypted data by using an SSE scheme while the corresponding symmetric key that is needed for the decryption is protected via a Ciphertext-Policy Attribute-Based Encryption scheme.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Computing Sciences
Contributors: Michalas, A.
Number of pages: 10
Pages: 146-155
Publication date: 2019

Host publication information

Title of host publication: Proceedings of the 34th ACM/SIGAPP Symposium on Applied Computing
Publisher: ACM
ISBN (Print): 9781450359337
ASJC Scopus subject areas: Software
Keywords: Access Control, Attribute-Based Encryption, Cloud Security, Hybrid Encryption, Policies, Storage Protection, Symmetric Searchable Encryption
Source: Scopus
Source ID: 85065666090

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Zeffiro User Interface for Electromagnetic Brain Imaging: a GPU Accelerated FEM Tool for Forward and Inverse Computations in Matlab

This article introduces the Zeffiro interface (ZI) version 2.2 for brain imaging. ZI aims to provide a simple, accessible and multimodal open source platform for finite element method (FEM) based and graphics processing unit (GPU) accelerated forward and inverse computations in the Matlab environment. It allows one to (1) generate a given multi-compartment head model, (2) to evaluate a lead field matrix as well as (3) to invert and analyze a given set of measurements. GPU acceleration is applied in each of the processing stages (1)–(3). In its current configuration, ZI includes forward solvers for electro-/magnetoencephalography (EEG) and linearized electrical impedance tomography (EIT) as well as a set of inverse solvers based on the hierarchical Bayesian model (HBM). We report the results of EEG and EIT inversion tests performed with real and synthetic data, respectively, and demonstrate numerically how the inversion parameters affect the EEG inversion outcome in HBM. The GPU acceleration was found to be essential in the generation of the FE mesh and the LF matrix in order to achieve a reasonable computing time. The code package can be extended in the future based on the directions given in this article.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: Inverse Problems
Contributors: He, Q., Rezaei, A., Pursiainen, S.
Number of pages: 14
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Neuroinformatics
ISSN (Print): 1539-2791
Ratings: 
  • Scopus rating (2019): CiteScore 8.2 SJR 1.984 SNIP 2.238
Original language: English
ASJC Scopus subject areas: Software, Neuroscience(all), Information Systems
Keywords: Electrical Impedance Tomography (EIT), Electro-/Magnetoencephalography (EEG/MEG), Finite Element Method (FEM), Hierarchical Bayesian Model (HBM), Matlab Interface
Source: Scopus
Source ID: 85074501520

Research output: Contribution to journalArticleScientificpeer-review

On the Secrecy Capacity of Fisher-Snedecor F Fading Channels

The performance of physical-layer security of the classic Wyner's wiretap model over Fisher-Snedecor composite fading channels is considered in this work. Specifically, F the main channel (i.e., between the source and the legitimate destination) and the eavesdropper's channel (i.e., between the source and the illegitimate destination) are assumed to experience independent quasi-static Fisher-Snedecor fading conditions, which have been shown to be encountered in realistic wireless transmission scenarios in conventional and emerging communication systems. In this context, exact closed-form expressions for the average secrecy capacity (ASC) and the probability of non-zero secrecy capacity (PNSC) are derived. Additionally, an asymptotic analytical expression for the ASC is presented. The impact of shadowing and multipath fading on the secrecy performance is investigated. Our results show that increasing the fading parameter of the main channel and/or the shadowing parameter of the eavesdropper's channel improves the secrecy performance. The analytical results are compared with Monte-Carlo simulations to validate the analysis.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research group: Wireless Communications and Positioning, Electrical Engineering, German Jordanian University, Khalifa University, University of Surrey, Queen's University, Belfast, Northern Ireland, Manchester Metropolitan University, Universidade Federal do Ceara
Contributors: Badarneh, O. S., Sofotasios, P. C., Muhaidat, S., Cotton, S. L., Rabie, K., Al-Dhahir, N.
Number of pages: 6
Pages: 102-107
Publication date: 26 Dec 2018

Host publication information

Title of host publication: 2018 14th International Conference on Wireless and Mobile Computing, Networking and Communications, WiMob 2018
Publisher: IEEE
ISBN (Electronic): 9781538668764
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software
Source: Scopus
Source ID: 85060830976

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

The N∗Fisher-Snedecor F Cascaded Fading Model

The Fisher-Snedecor F distribution was recently proposed as an accurate and tractable composite fading model in the context of device-to-device communications. The present work derives the product of the Fisher-Snedecor F composite fading model, which is useful in characterizing fading effects in numerous realistic communication scenarios. To this end, novel analytic expressions are first derived for the probability density function, the cumulative distribution function and the moment of the product of N statistically independent, but not necessarily identically distributed, Fisher-Snedecor F random variables. Capitalizing on these expressions, we derive tractable closed-form expressions for channel quality estimation of the proposed model as well as the corresponding outage probability and average bit error probability for binary modulations. The offered results are corroborated by extensive Monte-Carlo simulation results, which verify the validity of the derived expressions. It is shown that the number of cascaded channels affects considerably the corresponding performance, as a variation of over an order of magnitude is observed across all signal-to-noise ratio regimes.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research group: Wireless Communications and Positioning, Electrical Engineering, German Jordanian University, Khalifa University, University of Surrey, Queen's University, Belfast, Northern Ireland, Manchester Metropolitan University, Universidade Federal do Ceara
Contributors: Badarneh, O. S., Muhaidat, S., Sofotasios, P. C., Cotton, S. L., Rabie, K., Da Costa, D. B.
Publication date: 26 Dec 2018

Host publication information

Title of host publication: 2018 14th International Conference on Wireless and Mobile Computing, Networking and Communications, WiMob 2018
Publisher: IEEE
ISBN (Electronic): 9781538668764
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software
Source: Scopus
Source ID: 85060794044

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Power mitigation of a heterogeneous multicore architecture on FPGA/ASIC by DFS/DVFS techniques

This article presents an integrated self-aware computing model in a Heterogeneous Multicore Architecture (HMA) to mitigate the power dissipation of an Orthogonal Frequency-Division Multiplexing (OFDM) receiver. The proposed platform consists of template-based Coarse-Grained Reconfigurable Array (CGRA) devices connected through a Network-on-Chip (NoC) around a few Reduced Instruction-Set Computing (RISC) cores. The self-aware computing model exploits Feedback Control System (FCS) which constantly monitors the execution-time of each core and dynamically scales the operating frequency of each node of the NoC depending on the worst execution-time. Therefore, the performance of the overall system is equalized towards a desired level besides mitigating the power dissipation. Measurement results obtained from Field-Programmable Gate Array (FPGA) synthesis show up to 20.2% dynamic power dissipation and 16.8% total power dissipation savings. Since FCS technique can be employed for scaling the frequency and the voltage and on the other hand, voltage supply cannot be scaled on the FPGA-based prototyped platform, the implementation is also estimated in 28nm Ultra-Thin Body and Buried oxide (UTBB) Fully-Depleted Silicon-On-Insulator (FD-SOI) Application-Specific Integrated Circuit (ASIC) technology to scale voltage in addition to frequency and get more benefits in terms of dynamic power dissipation reduction. Subsequent to synthesizing the whole platform on ASIC and scaling the voltage and frequency simultaneously as a Dynamic Voltage and Frequency Scaling (DVFS) method, significant dynamic power dissipation savings by 5.97X against Dynamic Frequency Scaling (DFS) method were obtained.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: System-on-Chip for GNSS, Wireless Communications and Cyber-Physical Embedded Computing, University of Bologna
Contributors: Nouri, S., Rossi, D., Nurmi, J.
Number of pages: 10
Pages: 259-268
Publication date: 1 Nov 2018
Peer-reviewed: Yes

Publication information

Journal: Microprocessors and Microsystems
Volume: 63
ISSN (Print): 0141-9331
Ratings: 
  • Scopus rating (2018): CiteScore 2.5 SJR 0.264 SNIP 0.941
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications, Artificial Intelligence
Keywords: Accelerator, ASIC, CGRA, Channel estimation, DVFS, FCS, FFT, FPGA, Frequency offset estimation, Heterogeneous, Multicore, Network-on-Chip, OFDM, Power mitigation, Receiver, Reconfigurable, Time synchronization
Source: Scopus
Source ID: 85054428146

Research output: Contribution to journalArticleScientificpeer-review

End-to-End Polyphonic Sound Event Detection Using Convolutional Recurrent Neural Networks with Learned Time-Frequency Representation Input

Sound event detection systems typically consist of two stages: Extracting hand-crafted features from the raw audio waveform, and learning a mapping between these features and the target sound events using a classifier. Recently, the focus of sound event detection research has been mostly shifted to the latter stage using standard features such as mel spectrogram as the input for classifiers such as deep neural networks. In this work, we utilize end-to-end approach and propose to combine these two stages in a single deep neural network classifier. The feature extraction over the raw waveform is conducted by a feedforward layer block, whose parameters are initialized to extract the time-frequency representations. The feature extraction parameters are updated during training, resulting with a representation that is optimized for the specific task. This feature extraction block is followed by (and jointly trained with) a convolutional recurrent network, which has recently given state-of-the-art results in many sound recognition tasks. The proposed system does not outperform a convolutional recurrent network with fixed hand-crafted features. The final magnitude spectrum characteristics of the feature extraction block parameters indicate that the most relevant information for the given task is contained in 0 - 3 kHz frequency range, and this is also supported by the empirical results on the SED performance.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Audio research group - ARG
Contributors: Cakir, E., Virtanen, T.
Publication date: 10 Oct 2018

Host publication information

Title of host publication: 2018 International Joint Conference on Neural Networks, IJCNN 2018 - Proceedings
Publisher: IEEE
Article number: 8489470
ISBN (Electronic): 9781509060146
ASJC Scopus subject areas: Software, Artificial Intelligence
Keywords: convolutional recurrent neural networks, end-to-end, feature learning, neural networks

Bibliographical note

jufoid=58177

Source: Scopus
Source ID: 85056548407

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Guidelines for development and evaluation of usage data analytics tools for human-machine interactions with industrial manufacturing systems

We present the lessons learned during the development and evaluation process for UX-sensors, a visual data analytics tool for inspecting logged usage data from flexible manufacturing systems (FMS). Based on the experiences during a collaborative development process with practitioners from one FMS supplier company, we propose guidelines to support other developers of visual data analytics tools for usage data logging in context of complex industrial systems. For instance, involving stakeholders with different roles can help to identify user requirements and generate valuable development ideas. Tool developers should confirm early access to real usage data from customers' systems and familiarize themselves with the log data structure. We argue that combining expert evaluations with field study methods can provide a more diverse set of usability issues to address. For future research, we encourage studies on insights emerging from usage data analytics and their impact on the viewpoints of the supplier and customer.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: User experience, University of Wisconsin-Stevens Point, Fastems
Contributors: Varsaluoma, J., Väätäjä, H., Heimonen, T., Tiitinen, K., Hakulinen, J., Turunen, M., Nieminen, H.
Number of pages: 10
Pages: 172-181
Publication date: 10 Oct 2018

Host publication information

Title of host publication: Mindtrek 2018 - Proceedings of the 22nd International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450365895
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software

Bibliographical note

EXT="Nieminen, Harri"

Source: Scopus
Source ID: 85056717713

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Implications of audio and narration in the user experience design of virtual reality

Virtual reality (VR) is quickly gaining momentum as an immersive medium; however, there is much to learn about the design elements needed to create a positive experience. In this paper, we present the second wave of user testing of a journalistic and cultural VR experience that tells the story of a well-known artist through his art. The storytelling elements narration and ambient music were added to the initial prototype and tested in the field with 32 participants. Our results showed that the improvements produced a mostly positive user experience and shed light on what could be further improved in the case of our prototype, the field of immersive journalism, and VR used in the cultural context.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: User experience, Sanoma
Contributors: Kelling, C., Karhu, J., Kauhanen, O., Turunen, M., Väätäjä, H., Lindqvist, V.
Number of pages: 4
Pages: 258-261
Publication date: 10 Oct 2018

Host publication information

Title of host publication: Mindtrek 2018 - Proceedings of the 22nd International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450365895
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Cultural VR, Immersive Journalism, Museum, Storytelling

Bibliographical note

INT=tie,"Kauhanen, Otto"

Source: Scopus
Source ID: 85056721502

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Multichannel Sound Event Detection Using 3D Convolutional Neural Networks for Learning Inter-channel Features

In this paper, we propose a stacked convolutional and recurrent neural network (CRNN) with a 3D convolutional neural network (CNN) in the first layer for the multichannel sound event detection (SED) task. The 3D CNN enables the network to simultaneously learn the inter-and intra-channel features from the input multichannel audio. In order to evaluate the proposed method, multichannel audio datasets with different number of overlapping sound sources are synthesized. Each of this dataset has a four-channel first-order Ambisonic, binaural, and single-channel versions, on which the performance of SED using the proposed method are compared to study the potential of SED using multichannel audio. A similar study is also done with the binaural and single-channel versions of the real-life recording TUT-SED 2017 development dataset. The proposed method learns to recognize overlapping sound events from multichannel features faster and performs better SED with a fewer number of training epochs. The results show that on using multichannel Ambisonic audio in place of single-channel audio we improve the overall F-score by 7.5%, overall error rate by 10% and recognize 15.6% more sound events in time frames with four overlapping sound sources.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Aalto University
Contributors: Adavanne, S., Politis, A., Virtanen, T.
Publication date: 10 Oct 2018

Host publication information

Title of host publication: 2018 International Joint Conference on Neural Networks, IJCNN 2018 - Proceedings
Publisher: IEEE
Article number: 8489542
ISBN (Electronic): 9781509060146
ASJC Scopus subject areas: Software, Artificial Intelligence

Bibliographical note

jufoid=58177

Source: Scopus
Source ID: 85056497231

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Robotic process automation - Creating value by digitalizing work in the private healthcare?

Organizations are applying digitalization to the constantly increasing amounts of different organizational processes [2]. The healthcare sector is also changing and actively seeking better ways to enhance performance, especially in the private healthcare sector [7]. Automation of workflow processes, e.g., Robotic Process Automation (RPA), in organizations has been emerging as a solution to this demand [3, 4]. To meet this clear demand, automation of workflow processes in organizations has been a rising trend during the past few years [3]. We analyze the value creating functions of the RPA potential in the private healthcare industry sector, using modified Walter et al.’s function-oriented value analysis as our theoretical lens for identifying the potential of RPA.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Industrial and Information Management
Contributors: Ratia, M., Myllärniemi, J., Helander, N.
Number of pages: 6
Pages: 222-227
Publication date: 10 Oct 2018

Host publication information

Title of host publication: Mindtrek 2018 - Proceedings of the 22nd International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450365895
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Digitalization of knowledge work, Healthcare, Robotic Process Automation, Value creation
Source: Scopus
Source ID: 85056714767

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Systematic literature review on user logging in virtual reality

In this systematic literature review, we study the role of user logging in virtual reality research. By categorizing literature according to data collection methods and identifying reasons for data collection, we aim to find out how popular user logging is in virtual reality research. In addition, we identify publications with detailed descriptions about logging solutions. Our results suggest that virtual reality logging solutions are relatively seldom described in detail despite that many studies gather data by body tracking. Most of the papers gather data to witness something about a novel functionality or to compare different technologies without discussing logging details. The results can be used for scoping future virtual reality research.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Software engineering
Contributors: Luoto, A.
Number of pages: 8
Pages: 110-117
Publication date: 10 Oct 2018

Host publication information

Title of host publication: Mindtrek 2018 - Proceedings of the 22nd International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450365895
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Systematic Literature Review, User Logging
Electronic versions: 
Source: Scopus
Source ID: 85056744675

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

The Finnish you – An interactive storytelling application for an airport environment

Traveling should be full of excitement and new experiences. However, a chaotic airport environment and constant waiting often halt these pleasurable feelings. Although passengers can spend their time shopping, they are unlikely to connect personally to the products. Furthermore, airport services seldom highlight the local culture that passengers miss by being confined to the airport. To address these shortcomings, we present a mobile web-application, called “The Finnish You”. Utilizing the elements of interactive storytelling and gamification, the application guides users through shops and brands in the airport while teaching about the local culture in a personalized way. The application was tested in a user study with nine participants in a controlled office environment and was seen as a satisfactory way to spend time waiting in the airport. Our findings show how a personalized storytelling approach may convert ordinary shopping activity into a culture-learning adventure. We further suggest implications for the design of storytelling applications regarding the airport context of use.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Faculty of Computing and Electrical Engineering, Pervasive Computing, Research area: User experience, Human-Centered Technology (IHTE)
Contributors: Burova, A., Kelling, C., Hakulinen, J., Kallioniemi, P., Keskinen, T., Turunen, M., Väätäjä, H.
Number of pages: 10
Pages: 182-191
Publication date: 10 Oct 2018

Host publication information

Title of host publication: Mindtrek 2018 - Proceedings of the 22nd International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450365895
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Airport Environment, Digital Storytelling, Gamification, Mobile Web-Application, User Experience
Source: Scopus
Source ID: 85056694022

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Graph measures with high discrimination power revisited: A random polynomial approach

Finding graph measures with high discrimination power has been triggered by searching for so-called complete graph invariants. In a series of papers, we have already investigated highly discriminating measures to distinguish graphs (networks) based on their topology. In this paper, we propose an approach where the graph measures are based on the roots of random graph polynomials. The polynomial coefficients have been defined by utilizing information functionals which capture structural information of the underlying networks. Our numerical results obtained by employing exhaustively generated graphs reveal that the new approach outperforms earlier results in the literature.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Computational Medicine and Statistical Learning Laboratory (CMSL), Research group: Predictive Society and Data Analytics (PSDA), University of Applied Sciences Upper Austria, School of Management, Nankai University
Contributors: Dehmer, M., Chen, Z., Emmert-Streib, F., Shi, Y., Tripathi, S.
Number of pages: 8
Pages: 407-414
Publication date: 1 Oct 2018
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 467
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2018): CiteScore 10.4 SJR 1.62 SNIP 2.744
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Data science, Graphs, Networks, Quantitative graph theory, Statistics

Bibliographical note

EXT="Tripathi, Shailesh"

Source: Scopus
Source ID: 85051518614

Research output: Contribution to journalArticleScientificpeer-review

Reproducible Evaluation of System Efficiency with a Model of Architecture: From Theory to Practice

Current trends in high performance and embedded computing include design of increasingly complex hardware architectures with high parallelism, heterogeneous processing elements and non-uniform communication resources. In order to take hardware and software design decisions, early evaluations of the system non-functional properties are needed. These evaluations of system efficiency require Electronic System-Level (ESL) information on both the algorithms and the architecture. Contrary to algorithm models for which a major body of work has been conducted on defining formal Models of Computation (MoCs), architecture models from the literature are mostly empirical models from which reproducible experimentation requires the accompanying software. In this paper, a precise definition of a Model of Architecture (MoA) is proposed that focuses on reproducibility and abstraction and removes the overlap previously existing between the notions of MoA and MoC. A first MoA, called the Linear System-Level Architecture Model (LSLA), is presented. To demonstrate the generic nature of the proposed new architecture modeling concepts, we show that the LSLA Model can be integrated flexibly with different MoCs. LSLA is then used to model the energy consumption of a State-of-the-Art Multiprocessor System-on-Chip (MPSoC) when running an application described using the Synchronous Dataflow (SDF) MoC. A method to automatically learn LSLA model parameters from platform measurements is introduced. Despite the high complexity of the underlying hardware and software, a simple LSLA model is demonstrated to estimate the energy consumption of the MPSoC with a fidelity of 86%.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, UBL, Scuola Superiore sant'Anna, University of Maryland
Contributors: Pelcat, M., Mercat, A., Desnos, K., Maggiani, L., Liu, Y., Heulot, J., Nezan, J. F., Hamidouche, W., Menard, D., Bhattacharyya, S. S.
Pages: 2050-2063
Publication date: Oct 2018
Peer-reviewed: Yes
Early online date: 16 Nov 2017

Publication information

Journal: IEEE Transactions on Computer-Aided Design of Integrated Circuits and Systems
Volume: 37
Issue number: 10
ISSN (Print): 0278-0070
Ratings: 
  • Scopus rating (2018): CiteScore 4.6 SJR 0.476 SNIP 1.737
Original language: English
ASJC Scopus subject areas: Software, Computer Graphics and Computer-Aided Design, Electrical and Electronic Engineering
Keywords: Algorithm design and analysis, architecture, Complexity theory, Computational modeling, Computer architecture, design space exploration, Energy consumption, Hardware, hardware/software co-design, modeling, multiprocessor SoC, performance optimization, Ports (Computers), power modeling and estimation., system on chip
Source: Scopus
Source ID: 85035150836

Research output: Contribution to journalArticleScientificpeer-review

Designing for experiences with socially interactive robots

Socially interactive technologies are emerging as one of the predominant technologies of the future. In this workshop, we aim to discuss the emerging field of Social Robotic technologies with a particular focus on interaction design methodologies used in the design process. The workshop will investigate how researchers have approached designing social robots and what we can learn from the interaction design field for future designs. The main activities of the workshop will encompass two interactive sessions and a discussion panel on approaches to inspire the design of socially interactive robots. In particular, we focus on experience-driven design methods involving rituals and memorable experiences with social robots.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: User experience, Uppsala University, Strate School of Design
Contributors: Obaid, M., Kaipainen, K., Ocnarescu, I., Ahtinen, A.
Number of pages: 4
Pages: 948-951
Publication date: 29 Sep 2018

Host publication information

Title of host publication: NordiCHI 2018 : Revisiting the Life Cycle - Proceedings of the 10th Nordic Conference on Human-Computer Interaction
Publisher: ACM
ISBN (Electronic): 9781450364379
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Design, Social, Social Robot, Technology, User Experience
Source: Scopus
Source ID: 85056571102

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Understanding animals: A critical challenge in ACI

We present a qualitative content analysis of visual-verbal social media posts, where ordinary dog owners pretend to be their canine, to identify meaningful facets in their dogs' life-worlds, e.g. pleasures of human-dog relation, dog-dog relations, food etc. We use this knowledge to inform design of “quantified pets”. The study targets a general problem in Animal-Computer Interaction (ACI), i.e. to understand animals when designing “for” them, although lacking a common language. Several approaches, e.g. ethnography and participatory design, have been appropriated from HCI without exhausting the issue. We argue for a methodological creativity and pluralism by suggesting an additional approach drawing on “kinesthetic empathy”. It implies to understand animals by empathizing with their bodily movements over time and decoding the realities of their life-worlds. This, and other related approaches, has inspired animal researchers to conduct more or less radical participant observations during extensive duration to understand the perspective of the other. We suggest that dog owners whom share their lives with their dogs already possess a similar understanding as these experts, and thus uphold important experiences of canine life that could be used to understand individual dogs and inspire design.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: User experience, Stockholm University
Contributors: Aspling, F., Juhlin, O., Väätäjä, H.
Number of pages: 13
Pages: 148-160
Publication date: 29 Sep 2018

Host publication information

Title of host publication: NordiCHI 2018 : Revisiting the Life Cycle - Proceedings of the 10th Nordic Conference on Human-Computer Interaction
Publisher: ACM
ISBN (Electronic): 9781450364379
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Animal-Computer Interaction, Dog Blogs, Kinesthetic Empathy, Pet Dogs, Quantified Pets, Social Media
Source: Scopus
Source ID: 85056568856

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A joint target localization and classification framework for sensor networks

In this paper, we propose a joint framework for target localization and classification using a single generalized model for non-imaging based multi-modal sensor data. For target localization, we exploit both sensor data and estimated dynamics within a local neighborhood. We validate the capabilities of our framework by using a multi-modal dataset, which includes ground truth GPS information (e.g., time and position) and data from co-located seismic and acoustic sensors. Experimental results show that our framework achieves better classification accuracy compared to recent fusion algorithms using temporal accumulation and achieves more accurate target localizations than multilateration.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Computer engineering, U.S. Army Research Laboratory, University of Maryland
Contributors: Lee, K., Riggan, B. S., Bhattacharyya, S. S.
Number of pages: 5
Pages: 3076-3080
Publication date: 10 Sep 2018

Host publication information

Title of host publication: 2018 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2018 - Proceedings
Volume: 2018-April
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 8462641
ISBN (Print): 9781538646588
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Classification, Localization, Sensor fusion, Sensor networks, Tracking

Bibliographical note

JUFOID=57409

Source: Scopus
Source ID: 85054211699

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Estimation of time-varying room impulse responses of multiple sound sources from observed mixture and isolated source signals

This paper proposes a method for online estimation of time-varying room impulse responses (RIR) between multiple isolated sound sources and a far-field mixture. The algorithm is formulated as adaptive convolutive filtering in short-time Fourier transform (STFT) domain. We use the recursive least squares (RLS) algorithm for estimating the filter parameters due to its fast convergence rate, which is required for modeling rapidly changing RIRs of moving sound sources. The proposed method allows separation of reverberated sources from the far-field mixture given that their close-field signals are available. The evaluation is based on measuring unmixing performance (removal of reverberated source) using objective separation criteria calculated between the ground truth recording of the preserved sources and the unmixing result obtained with the proposed algorithm. We compare online and offline formulations for the RIR estimation and also provide evaluation with blind source separation algorithm only operating on the mixture signal.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Audio research group - ARG
Contributors: Nikunen, J., Virtanen, T.
Number of pages: 5
Pages: 421-425
Publication date: 10 Sep 2018

Host publication information

Title of host publication: 2018 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2018 - Proceedings
Volume: 2018-April
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 8462535
ISBN (Print): 9781538646588

Publication series

Name:  Proceedings of the IEEE International Conference on Acoustics, Speech, and Signal Processing
ISSN (Electronic): 2379-190X
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Adaptive filtering, Informed source separation, Online room impulse response estimation, Source unmixing

Bibliographical note

jufoid=57409

Source: Scopus
Source ID: 85054234348

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Low-energy graph fourier basis functions span salient objects

There is an emerging interest aiming at defining principles for signals on general graphs, which are analogous to the basic principles in traditional signal processing. One example is the Graph Fourier Transform which aims at decomposing a graph signal into its components based on a set of basis functions with corresponding graph frequencies. It has been observed that most of the important information of a graph signal is contained inside the low frequency band, which leads to several applications such as denoising, compression, etc. In this paper, we show that the low frequency basis functions span the salient regions in an image, which can also be considered as important regions. Motivated by this, we present a novel simple and unsupervised method to utilize a number of low-energy basis functions and show that it improves the performance of seven state-of-the-art salient object detection methods in five datasets under four different evaluation criteria, with only minor exceptions.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG
Contributors: Malik, J., Aytekin, C., Gabbouj, M.
Number of pages: 5
Pages: 1548-1552
Publication date: 10 Sep 2018

Host publication information

Title of host publication: 2018 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2018 - Proceedings
Volume: 2018-April
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 8462672
ISBN (Print): 9781538646588
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Graph fourier transform, Graph signal processing, Salient object detection

Bibliographical note

jufoid=57409

Source: Scopus
Source ID: 85054244934

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Statistical Evaluation of Visual Quality Metrics for Image Denoising

This paper studies the problem of full reference visual quality assessment of denoised images with a special emphasis on images with low contrast and noise-like texture. Denoising of such images together with noise removal often results in image details loss or smoothing. A new test image database, FLT, containing 75 noise-free 'reference' images and 300 filtered ('distorted') images is developed. Each reference image, corrupted by an additive white Gaussian noise, is denoised by the BM3D filter with four different values of threshold parameter (four levels of noise suppression). After carrying out a perceptual quality assessment of distorted images, the mean opinion scores (MOS) are obtained and compared with the values of known full reference quality metrics. As a result, the Spearman Rank Order Correlation Coefficient (SROCC) between PSNR values and MOS has a value close to zero, and SROCC between values of known full-reference image visual quality metrics and MOS does not exceed 0.82 (which is reached by a new visual quality metric proposed in this paper). The FLT dataset is more complex than earlier datasets used for assessment of visual quality for image denoising. Thus, it can be effectively used to design new image visual quality metrics for image denoising.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Computational Imaging-CI, National Aerospace University
Contributors: Egiazarian, K., Ponomarenko, M., Lukin, V., Ieremeiev, O.
Number of pages: 5
Pages: 6752-6756
Publication date: 10 Sep 2018

Host publication information

Title of host publication: 2018 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2018 - Proceedings
Volume: 2018-April
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 8462294
ISBN (Print): 9781538646588
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: BM3D, Full-reference metrics, Image denoising, Image visual quality assessment

Bibliographical note

EXT="Lukin, Vladimir"
JUFOID=57409

Source: Scopus
Source ID: 85054084165

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Low latency edge rendering scheme for interactive 360 degree virtual reality gaming

This paper describes the core functionality and a proof-of-concept demonstration setup for remote 360 degree stereo virtual reality (VR) gaming. In this end-to-end scheme, the execution of a VR game is off-loaded from an end user device to a cloud edge server in which the executed game is rendered based on user's field of view (FoV) and control actions. Headset and controller feedback is transmitted over the network to the server from which the rendered views of the game are streamed to a user in real-time as encoded HEVC video frames. This approach saves energy and computation load of the end terminals by making use of the latest advancements in network connection speed and quality. In the showcased demonstration, a VR game is run in Unity on a laptop powered by i7 7820HK processor and GTX 1070 GPU. The 360 degree spherical view of the game is rendered and converted to a rectangular frame using equirectangular projection (ERP). The ERP video is sliced vertically and only the FoV is encoded with Kvazaar HEVC encoder in real time and sent over the network in UDP packets. Another laptop is used for playback with a HTC Vive VR headset. Our system can reach an end-to-end latency of 30 ms and bit rate of 20 Mbps for stereo 1080p30 format.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Datacenter Infrastructure Modules, Nokia Technologies
Contributors: Viitanen, M., Vanne, J., Hämäläinen, T. D., Kulmala, A.
Number of pages: 4
Pages: 1557-1560
Publication date: 19 Jul 2018

Host publication information

Title of host publication: Proceedings - 2018 IEEE 38th International Conference on Distributed Computing Systems, ICDCS 2018
Publisher: IEEE
ISBN (Electronic): 9781538668719
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications
Keywords: 360 degree video, Edge computing, High Efficiency Video Coding (HEVC), Video coding, Virtual reality (VR)

Bibliographical note

jufoid=58061e

Source: Scopus
Source ID: 85050973480

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Liking the game: How can spectating motivations influence social media usage at live esports events?

There is no doubt that various social media services shape the ways in which we approach our daily lives. The ubiquitous nature of these services, afforded by mobile devices, means that we can take them with us wherever we go — including when we attend live events. Uncovering why individuals use social media during live events can help improve event organization, marketing, and the experiences of attendees. Our understanding of the motivations for using social media during live events is, however, still lacking in depth, especially in regard to emerging live events such as esports. This study aims to answer the question: what motivates the use of social media during live esports events? Data was gathered via a survey (N=255) at the ‘Assembly 2016’ LAN-event, a major live esports event. We examine the relationships between using various social media services and the motivations for esports spectating, through the Motivation Scale for Sports Consumption. While the results indicate that using social media services while attending Assembly 2016 was quite popular, it seemed that in many cases social media usage was a distraction from esports spectating, a core activity of the event. The results provide implications as to how marketers of live esports events should encourage or control usage of social media by attendees.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Gamification Group, Gamification Group
Contributors: Sjöblom, M., Hassan, L., Macey, J., Törhönen, M., Hamari, J.
Number of pages: 8
Pages: 160-167
Publication date: 18 Jul 2018

Host publication information

Title of host publication: Proceedings of the 9th International Conference on Social Media and Society, SMSociety 2018
Publisher: ACM
ISBN (Print): 9781450363341
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Esports, Live events, Motivation, Social media, Sports consumption
Electronic versions: 

Bibliographical note

EXT="Törhönen, Maria"
DUPL=44481582

Source: Scopus
Source ID: 85051509297

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Code notes: Designing a low-cost tangible coding tool for/with children

Programming has become an essential subject for today's education curriculum and as a result, the importance of creating the right environments to teach is increasing. For such environments, featuring tangible tools enhances creativity and collaboration. However, due to their high prices, current tangible tools are not reachable by most of the students. We developed Code Notes as a low-cost, attainable and tangible tool aimed to motivate children to support programming education. Code Notes is comprised of an Android app and code-cardboards to teach the basic concepts in programming. We continue to develop the platform with insights gained from children. This paper shares the design phases of Code Notes and observations from our two-month programming project. We also presented some future concepts of Code Notes that offer an active and embodied interaction with the teaching material.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Koç University
Contributors: Sabuncuoǧlu, A., Erkaya, M., Buruk, O. T., Göksun, T.
Number of pages: 6
Pages: 644-649
Publication date: 19 Jun 2018

Host publication information

Title of host publication: IDC 2018 - Proceedings of the 2018 ACM Conference on Interaction Design and Children
Publisher: ACM
ISBN (Electronic): 9781450351522
ASJC Scopus subject areas: Developmental and Educational Psychology, Education, Software, Human-Computer Interaction
Keywords: Affordable systems for education, Collaborative learning environments, Mobile learning, Tangible blocks.
Source: Scopus
Source ID: 85051492885

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Fast and easy live video service setup using lightweight virtualization

The service broker provides service providers with virtualized services that can be initialized rapidly and scaled up or down on demand. This demonstration paper describes how a service provider can set up a new video distribution service to end users with a diminutive effort. Our proposal makes use of Docker lightweight virtualization technologies that pack services in containers. This makes it possible to implement video coding and content delivery networks that are scalable and consume resources only when needed. The demonstration showcases a scenario where a video service provider sets up a new live video distribution service to end users. After the setup, live 720p30 video camera feed is encoded in real-time, streamed in HEVC MPEG-DASH format over CDN network, and accessed with a HbbTV compatible set-top-box. This end-to-end system illustrates that virtualization causes no significant resource or performance overhead but is a perfect match for online video services.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, VTT Technical Research Centre of Finland, Sofia Digital, VESTEL Elektronik
Contributors: Heikkinen, A., Pääkkönen, P., Viitanen, M., Vanne, J., Riikonen, T., Bakanoglu, K.
Number of pages: 3
Pages: 487-489
Publication date: 12 Jun 2018

Host publication information

Title of host publication: Proceedings of the 9th ACM Multimedia Systems Conference, MMSys 2018
Publisher: ACM
ISBN (Electronic): 9781450351928
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Software, Human-Computer Interaction
Keywords: Content Delivery Network (CDN), Docker, Dynamic adaptive streaming over HTTP (DASH), High Efficiency Video Coding (HEVC), Hybrid broadcast broadband TV (HbbTV), Virtualization
Source: Scopus
Source ID: 85050667891

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Optimized viewport dependent streaming of stereoscopic omnidirectional video

Streaming the whole omnidirectional video at high quality is less efficient in terms of bandwidth requirements and decoding complexity, since only a small part of the 360-degree horizontal field of view can be seen by a user at a given point in time. In Viewport Dependent Streaming (VDS) only the current user viewport is streamed at high quality, while the remaining parts are streamed at lower quality. This technology may save streaming bandwidth considerably, especially when it is associated to other techniques. Among the others, asymmetric stereoscopic video, has been studied in the past for traditional video and displays. We focused our research on the usage of asymmetric stereoscopic video for omnidirectional streams watched with a Head Mounted Display (HMD) in VDS. We conducted two subjective quality experiments with the main goal of reducing the streaming bandwidth, while keeping the subjective video quality at the highest level. We assessed asymmetric video applied separately to the foreground and background views of omnidirectional VDS sessions. We show that for VDS, applying asymmetric stereoscopic streaming delivery on the foreground view can save up to 41% bit rate, and using the same technique on the background view can save approximately up to 15% bit rate. Furthermore, eye dominance was seen not to be relevant in our experiments.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Nokia Technologies
Contributors: Naik, D., Curcio, I. D., Toukomaa, H.
Number of pages: 6
Pages: 37-42
Publication date: 12 Jun 2018

Host publication information

Title of host publication: Proceedings of the 23th ACM Workshop on Packet Video, PV 2018
Publisher: ACM
ISBN (Electronic): 9781450357739
ASJC Scopus subject areas: Human-Computer Interaction, Software
Keywords: 360 degrees video, Asymmetric video, Omnidirectional video, Streaming adaptation, Subjective quality evaluation, Virtual reality streaming

Bibliographical note

EXT="Curcio, Igor D.D."

Source: Scopus
Source ID: 85050644603

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A quasi-virtual online analyser based on an artificial neural networks and offline measurements to predict purities of raffinate/extract in simulated moving bed processes

The quality control and optimization of Simulated Moving Bed processes are still a challenge. Among the main reasons for that, the real time measurement of its main properties can be highlighted. Further developments in this field are necessary in order to allow the development of better control and optimization systems of these units. In the present work, a system composed by two Artificial Neural Networks working concomitantly with an offline measurement system is proposed, named Quasi-Virtual Analyser (Q-VOA) system. The development of the Q-VOA is presented and the system is simulated in order to evaluate its efficiency. The methodology used to select the input variables for the Q-VOA is another contribution of this work. The results show that the Q-VOA is capable of reducing the system errors and keep the prediction closer to the process true responses, when compared with the simple VOA system, which is based solely on model predictions. Furthermore, the results show the efficiency of the measurement system even under the presence of non-measured perturbations.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering, Univ Porto, Universidade do Porto, Fac Med, Dept Med Imaging, Federal Univ. of Bahia
Contributors: Nogueira, I. B., Ribeiro, A. M., Requião, R., Pontes, K. V., Koivisto, H., Rodrigues, A. E., Loureiro, J. M.
Number of pages: 19
Pages: 29-47
Publication date: 1 Jun 2018
Peer-reviewed: Yes

Publication information

Journal: Applied Soft Computing Journal
Volume: 67
ISSN (Print): 1568-4946
Ratings: 
  • Scopus rating (2018): CiteScore 8.9 SJR 1.216 SNIP 2.474
Original language: English
ASJC Scopus subject areas: Software
Keywords: Artificial neural network, Enantiomers separation, Purity measurement, Quasi-virtual analyser system, True moving bed
Source: Scopus
Source ID: 85043383206

Research output: Contribution to journalArticleScientificpeer-review

Looking for a five-legged sheep: Identifying enterprise architects' skills and competencies

Enterprise architecture (EA) is a holistic approach to comprehend the organization's business objectives and processes, data resources, information systems and information technologies. To advance EA activities, organizations need a myriad of different skills and competences both from individual enterprise architects and from architect teams. However, research on these skills and competences is scarce. Not knowing what skills are actually needed might be one of the reasons why public sector EA endeavors have been very problematic. In this paper, we conduct a qualitative survey among enterprise architects themselves to identify which skills they consider essential for EA work. Our results indicate that the range of skills is great, and finding an expert with all appropriate competencies is like looking for a fivelegged sheep.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Industrial and Information Management
Contributors: Ylinen, M., Pekkola, S.
Publication date: 30 May 2018

Host publication information

Title of host publication: Proceedings of the 19th Annual International Conference on Digital Government Research : Governance in the Data Age, DG.O 2018
Publisher: ACM
Article number: a58
ISBN (Electronic): 9781450365260
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Source: Scopus
Source ID: 85049050136

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Toward efficient many-core scheduling of partial expansion graphs

Transformation of synchronous data flow graphs (SDF) into equivalent homogeneous SDF representations has been extensively applied as a pre-processing stage when mapping signal processing algorithms onto parallel platforms. While this transformation helps fully expose task and data parallelism, it also presents several limitations such as an exponential increase in the number of actors and excessive communication overhead. Partial expansion graphs were introduced to address these limitations for multi-core platforms. However, existing solutions are not well-suited to achieve efficient scheduling on many-core architectures. In this article, we develop a new approach that employs cyclo-static data flow techniques to provide a simple but efficient method of coordinating the data production and consumption in the expanded graphs. We demonstrate the advantage of our approach through experiments on real application models.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Computer engineering, Parc Scientifique de la Haute Borne, University of Maryland
Contributors: Tran, H. N., Bhattacharyya, S. S., Talpin, J. P., Gautier, T.
Number of pages: 4
Pages: 100-103
Publication date: 28 May 2018

Host publication information

Title of host publication: Proceedings of the 21st International Workshop on Software and Compilers for Embedded Systems, SCOPES 2018
Publisher: Association for Computing Machinery, Inc
ISBN (Print): 9781450357807
ASJC Scopus subject areas: Hardware and Architecture, Software
Source: Scopus
Source ID: 85054140820

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Preface: Special Issue on ‘New Hydraulic Components for Tough Robots’

General information

Publication status: Published
MoE publication type: B1 Article in a scientific magazine
Organisations: Automation and Hydraulic Engineering, Research group: Innovative Hydraulic Automation, Tokyo Institute of Technology, Ritsumeikan University, Italian Institute of Technology, Okayama University
Contributors: Suzumori, K., Hyon, S. H., Semini, C., Mattila, J., Kanda, T.
Number of pages: 1
Publication date: 3 May 2018
Peer-reviewed: No

Publication information

Journal: Advanced Robotics
Volume: 32
Issue number: 9
ISSN (Print): 0169-1864
Ratings: 
  • Scopus rating (2018): CiteScore 2.7 SJR 0.346 SNIP 0.886
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Software, Human-Computer Interaction, Hardware and Architecture, Computer Science Applications
Source: Scopus
Source ID: 85047515551

Research output: Contribution to journalEditorialScientific

On the Definition of Microservice Bad Smells

Code smells and architectural smells (also called bad smells) are symptoms of poor design that can hinder code understandability and decrease maintainability. Several bad smells have been defined in the literature for both generic architectures and specific architectures. However, cloud-native applications based on microservices can be affected by other types of issues. In order to identify a set of microservice-specific bad smells, researchers collected evidence of bad practices by interviewing 72 developers with experience in developing systems based on microservices. Then, they classified the bad practices into a catalog of 11 microservice-specific bad smells frequently considered harmful by practitioners. The results can be used by practitioners and researchers as a guideline to avoid experiencing the same difficult situations in the systems they develop.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing
Contributors: Taibi, D., Lenarduzzi, V.
Number of pages: 7
Pages: 56-62
Publication date: 1 May 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Software
Volume: 35
Issue number: 3
ISSN (Print): 0740-7459
Ratings: 
  • Scopus rating (2018): CiteScore 5.3 SJR 0.549 SNIP 2.444
Original language: English
ASJC Scopus subject areas: Software
Keywords: anti-pattern, antipattern, architectural smell, bad smell, cloud computing, code smell, microservice, software development, software engineering
Source: Scopus
Source ID: 85046708734

Research output: Contribution to journalArticleScientificpeer-review

Backshoring of production in the context of a small and open Nordic economy

Purpose – The purpose of this paper is to investigate the extent, drivers, and conditions underlying backshoring in the Finnish manufacturing industry, comparing the results to the wider ongoing relocation of production in the international context. Design/methodology/approach – The survey of 229 Finnish manufacturing firms reveals the background, drivers, and patterns of offshoring and backshoring. Findings – Companies that had transferred their production back to Finland were more commonly in industries with relatively higher technology intensity and they were typically larger than the no-movement companies, and with a higher number of plants. They also reported more commonly having a corporate-wide strategy for guiding production location decisions. Research limitations/implications – Backshoring activity in the small and open economy of Finland seems to be higher compared to earlier studies in larger countries. The findings suggest that there is a transformation in the manufacturing industries with some gradual replacement of labor-intensive and lower technology-intensive industries toward higher technology-intensive industries. Practical implications – Moving production across national borders is one option in the strategies of firms to stay competitive. Companies must carefully consider the relevance of various decision-making drivers when determining strategies for their production networks. Social implications – Manufacturing industries have traditionally been important for employment in the relatively small and open economies of the Nordic countries. From the social perspective, it is important to understand the ongoing transformation and its implications. Originality/value – There are few empirical studies available of the ongoing backshoring movement, utilizing data from company decision makers instead of macroeconomic factors.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Industrial and Information Management, Research group: Center for Research on Operations Projects and Services
Contributors: Heikkilä, J., Martinsuo, M., Nenonen, S.
Number of pages: 19
Pages: 658-675
Publication date: May 2018
Peer-reviewed: Yes
Early online date: 27 Nov 2017

Publication information

Journal: Journal of Manufacturing Technology Management
Volume: 29
Issue number: 4
ISSN (Print): 1741-038X
Ratings: 
  • Scopus rating (2018): CiteScore 4.8 SJR 0.954 SNIP 1.393
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Computer Science Applications, Strategy and Management, Industrial and Manufacturing Engineering
Keywords: Manufacturing, Manufacturing strategy, Production
Source: Scopus
Source ID: 85039840754

Research output: Contribution to journalArticleScientificpeer-review

Towards secure cloud orchestration for multi-cloud deployments

Cloud orchestration frameworks are commonly used to deploy and operate cloud infrastructure. Their role spans both vertically (deployment on infrastructure, platform, application and microservice levels) and horizontally (deployments from many distinct cloud resource providers). However, despite the central role of orchestration, the popular orchestration frameworks lack mechanisms to provide security guarantees for cloud operators. In this work, we analyze the security landscape of cloud orchestration frameworks for multi-cloud infrastructure. We identify a set of attack scenarios, define security enforcement enablers and propose an architecture for a security-enabled cloud orchestration framework for multi-cloud application deployments.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, RISE SICS, University of Westminster
Contributors: Paladi, N., Michalas, A., Dang, H. V.
Publication date: 23 Apr 2018

Host publication information

Title of host publication: CrossCloud 2018 - 5th Workshop on CrossCloud Infrastructures and Platforms, colocated with EuroSys 2018
Publisher: ACM
Article number: a4
ISBN (Electronic): 9781450356534
ASJC Scopus subject areas: Information Systems, Software, Computer Science Applications
Keywords: Cloud infrastructure, Microser-vices, Orchestration, Security, Virtualization
Source: Scopus
Source ID: 85049685222

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Ripple thermostat: Affecting the emotional experience through interactive force feedback and shape change

Force feedback and shape change are modalities with a growing application potential beyond the more traditional GUIs. We present two studies that explored the effect of these modalities on the emotional experience when interacting with an intelligent thermostat. The first study compared visual feedback, force feedback, and a combination of force feedback and shape change. Results indicate that force feedback correlates to experienced dominance during interaction, while shape change mainly affects experienced arousal. The second study explored how force feedback and shape change could communicate affective meaning during interaction with the thermostat through a co-design study. Participants designed the thermostat behavior for three scenarios supporting energy savings. Results suggest that despite their abstractness, force feedback and shape change convey affective meaning during the user-system dialogue. The findings contribute to the design of intelligible and intuitive feedback.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Aarhus Universitet, Eindhoven University of Technology, Vincit
Contributors: Van Oosterhout, A., Alonso, M. B., Jumisko-Pyykkö, S.
Publication date: 20 Apr 2018

Host publication information

Title of host publication: Proceedings of the 2018 CHI Conference on Human Factors in Computing Systems
Publisher: ACM
Article number: 655
ISBN (Electronic): 9781450356206
ASJC Scopus subject areas: Human-Computer Interaction, Computer Graphics and Computer-Aided Design, Software
Keywords: Actuated interfaces, Affective computing, Haptic force feedback, Shape-changing interfaces
Source: Scopus
Source ID: 85046938728

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A design tool for high performance image processing on multicore platforms

Design and implementation of smart vision systems often involve the mapping of complex image processing algorithms into efficient, real-time implementations on multicore platforms. In this paper, we describe a novel design tool that is developed to address this important challenge. A key component of the tool is a new approach to hierarchical dataflow scheduling that integrates a global scheduler and multiple local schedulers. The local schedulers are lightweight modules that work independently. The global scheduler interacts with the local schedulers to optimize overall memory usage and execution time. The proposed design tool is demonstrated through a case study involving an image stitching application for large scale microscopy images.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, University of Maryland, National Institute of Standards and Technology
Contributors: Wu, J., Blattner, T., Keyrouz, W., Bhattacharyya, S. S.
Number of pages: 6
Pages: 1304-1309
Publication date: 19 Apr 2018

Host publication information

Title of host publication: Proceedings of the 2018 Design, Automation and Test in Europe Conference and Exhibition, DATE 2018
Publisher: IEEE
ISBN (Electronic): 9783981926316
ASJC Scopus subject areas: Safety, Risk, Reliability and Quality, Hardware and Architecture, Software, Information Systems and Management
Source: Scopus
Source ID: 85048740891

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Deep multiresolution color constancy

In this paper, a computational color constancy method is proposed via estimating the illuminant chromaticity in a scene by pooling from many local estimates. To this end, first, for each image in a dataset, we form an image pyramid consisting of several scales of the original image. Next, local patches of certain size are extracted from each scale in this image pyramid. Then, a convolutional neural network is trained to estimate the illuminant chromaticity per-patch. Finally, two more consecutive trainings are conducted, where the estimation is made per-image via taking the mean (1st training) and median (2nd training) of local estimates. The proposed method is shown to outperform the state-of-the-art in a widely used color constancy dataset.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Intel Finland
Contributors: Aytekin, C., Nikkanen, J., Gabbouj, M.
Number of pages: 5
Pages: 3735-3739
Publication date: 20 Feb 2018

Host publication information

Title of host publication: 2017 IEEE International Conference on Image Processing, ICIP 2017 - Proceedings
Publisher: IEEE COMPUTER SOCIETY PRESS
ISBN (Electronic): 9781509021758
ASJC Scopus subject areas: Software, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Color constancy, Deep learning, Illuminant chromaticity estimation, Local estimation, Multi-resolution

Bibliographical note

jufoid=57423

Source: Scopus
Source ID: 85045299547

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A multi-agent approach for processing industrial enterprise data

The C2NET project aims to provide cloud-based platform for the supply chain interactions. The architecture of such platform includes a Data Collection Framework (DCF) for managing the collection of the company's data. The DCF collects, transforms and stores data from both Internet of Things (IoT) devices in the factory shopfloor and company enterprises data via two types of hub; Legacy system hub (LSH) and IoT hub. Since the C2NET, targets the Small and Medium-sized Enterprises (SMEs), the enterprise data, or legacy data as called in the C2NET project, can be provided via excel files. Thus, this research work highlights a technique for processing the excel files in the LSHs. This technique adopts the concept of Multi-Agent Systems for processing the data as table in the excel files in the LSH. The multi-agent approach allows the LSH to process any excel file regardless the complexity in the data structure or in the file table. Furthermore, the presented approach enhances the processing of the excel files in different aspects, such as the size of the excel file or the required processing power.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation and Hydraulic Engineering, Research group: Automation and Systems Theory, Universitat Politècnica de València, Instituto de Desenvolvimento de Novas Tecnologias
Contributors: Mohammed, W. M., Ferrer, B. R., Martinez, J. L., Sanchis, R., Andres, B., Agostinho, C.
Number of pages: 7
Pages: 1209-1215
Publication date: 2 Feb 2018

Host publication information

Title of host publication: 2017 International Conference on Engineering, Technology and Innovation : Engineering, Technology and Innovation Management Beyond 2020: New Challenges, New Approaches, ICE/ITMC 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781538607749
ASJC Scopus subject areas: Computer Science Applications, Software, Engineering (miscellaneous), Computer Networks and Communications
Keywords: Cloud Based, Data Collection, Enterprise, Multi-Agent Systems, supply Chain
Source: Scopus
Source ID: 85047492606

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

An approach to production scheduling optimization a case of an oil lubrication and hydraulic systems manufacturer

Cloud-enabled tools developed in the Cloud Collaborative Manufacturing Networks (C2NET) project address the needs of small and medium enterprises with respect to information exchange and visibility across the collaboration partners in the supply network, coupled with automated and collaborative production planning and supply management. This paper analyses a case of an oil lubrication and hydraulic systems manufacturer and describes a pilot application of C2NET where the production schedule is optimized according to the priorities of the pilot company. In this case the goal is a highly adaptive just-in-time manufacturing schedule with guaranteed on time delivery.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation and Hydraulic Engineering, VTT Technical Research Centre of Finland, Roberto Camp Fluidhouse Ltd.
Contributors: Katasonov, A., Lastusilta, T., Korvola, T., Saari, L., Bendas, D., Mohammed, W. M., Lee, A. N.
Number of pages: 8
Pages: 1123-1130
Publication date: 2 Feb 2018

Host publication information

Title of host publication: 2017 International Conference on Engineering, Technology and Innovation : Engineering, Technology and Innovation Management Beyond 2020: New Challenges, New Approaches, ICE/ITMC 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781538607749
ASJC Scopus subject areas: Computer Science Applications, Software, Engineering (miscellaneous), Computer Networks and Communications
Keywords: cloud-supported manufacturing, enterprise collaboration, information exchange, just-in-time manufacturing, Mixed-Integer Linear Programming, on time delivery, optimization, production scheduling, Small and Medium size Enterprise, supply network
Source: Scopus
Source ID: 85047524893

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Configuring and visualizing the data resources in a cloud-based data collection framework

The Manufacturing Enterprise Solutions Association (MESA) provided the abstract and general definition of the Manufacturing Execution Systems (MES). A dedicated function has been reserved for the data collection activities. In this matter, the Cloud Collaborative Manufacturing Networks (C2NET) project tends to provide a cloud based platform for hosting the interactions of the supply chain in a collaborative network. Within the architecture of the C2NET project, a Data Collection Framework (DCF) is designed to fulfill the function of data collection. This allows the companies to provide their data, which can be both enterprise and Internet of Things (IoT) devices type of data to the platform for further use. The collection of the data is achieved by a specific third party application, i.e., the Legacy System Hub (LSH). This research work presents the approach of configuring and visualizing the data resources in the C2NET platform. This approach employs the web-based applications and the help of the LSH. This permits the C2NET platform to adapt to any kind of third party application, which manipulates enterprise data, following the generic and flexible solution of this approach.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation and Hydraulic Engineering, Research group: Automation and Systems Theory, Instituto de Desenvolvimento de Novas Tecnologias
Contributors: Mohammed, W. M., Ferrer, B. R., Jose, L., Lastra, M., Aleixo, D., Agostinho, C.
Number of pages: 8
Pages: 1201-1208
Publication date: 2 Feb 2018

Host publication information

Title of host publication: 2017 International Conference on Engineering, Technology and Innovation : Engineering, Technology and Innovation Management Beyond 2020: New Challenges, New Approaches, ICE/ITMC 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781538607749
ASJC Scopus subject areas: Computer Science Applications, Software, Engineering (miscellaneous), Computer Networks and Communications
Keywords: Cloud Based, Data Collection, Data Resources, Supply Chain, Visualization

Bibliographical note

INT=aut,"Jose, L."

Source: Scopus
Source ID: 85047476305

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Exploiting suppliers' potential in construction innovations

There is a need to understand ways to enhance innovations in the construction industry. It is argued that suppliers have potential to develop new innovations, but they are largely neglected in earlier construction-related research. This research focuses on suppliers' role in construction innovations, and the aim of the research is to increase understanding of practices for exploiting suppliers' potential in that context. A qualitative, explanatory research strategy is employed in the context of construction industry in Finland. Eighteen interviews are conducted with contractors to discover experiences and practices related to suppliers' potential in construction innovations. The results reveal practices for exploiting supplier's potential in construction innovations. As a key contribution, the research shows that suppliers have an important role in construction innovation but exploitation of suppliers' potential is still rather underdeveloped.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research group: Center for Research on Operations Projects and Services, Industrial and Information Management
Contributors: Sariola, R.
Number of pages: 7
Pages: 678-684
Publication date: 2 Feb 2018

Host publication information

Title of host publication: 2017 International Conference on Engineering, Technology and Innovation : Engineering, Technology and Innovation Management Beyond 2020: New Challenges, New Approaches, ICE/ITMC 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781538607749
ASJC Scopus subject areas: Computer Science Applications, Software, Engineering (miscellaneous), Computer Networks and Communications
Keywords: construction innovation, project networks, supplier management
Source: Scopus
Source ID: 85047528988

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Memory-Constrained vectorization and scheduling of dataflow graphs for hybrid CPU-GPU platforms

The increasing use of heterogeneous embedded systems with multi-core CPUs and Graphics Processing Units (GPUs) presents important challenges in effectively exploiting pipeline, task, and data-level parallelism to meet throughput requirements of digital signal processing applications. Moreover, in the presence of system-level memory constraints, hand optimization of code to satisfy these requirements is inefficient and error prone and can therefore, greatly slow down development time or result in highly underutilized processing resources. In this article, we present vectorization and scheduling methods to effectively exploit multiple forms of parallelism for throughput optimization on hybrid CPU-GPU platforms, while conforming to system-level memory constraints. The methods operate on synchronous dataflow representations, which are widely used in the design of embedded systems for signal and information processing. We show that our novel methods can significantly improve system throughput compared to previous vectorization and scheduling approaches under the same memory constraints. In addition, we present a practical case-study of applying our methods to significantly improve the throughput of an orthogonal frequency division multiplexing receiver system for wireless communications.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, University of Maryland, Department of Electrical and Computer Engineering
Contributors: Lin, S., Wu, J., Bhattacharyya, S. S.
Publication date: 1 Feb 2018
Peer-reviewed: Yes

Publication information

Journal: ACM Transactions on Embedded Computing Systems
Volume: 17
Issue number: 2
Article number: 50
ISSN (Print): 1539-9087
Ratings: 
  • Scopus rating (2018): CiteScore 3 SJR 0.326 SNIP 0.979
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture
Keywords: Dataflow models, Design optimization, Heterogeneous computing, Signal processing systems, Software synthesis
Source: Scopus
Source ID: 85042527088

Research output: Contribution to journalArticleScientificpeer-review

Feature synthesis for image classification and retrieval via one-against-all perceptrons

Most existing content-based image retrieval and classification systems rely on low-level features which are automatically extracted from images. However, often these features lack the discrimination power needed for accurate description of the image content, and hence, they may lead to a poor retrieval or classification performance. We propose a novel technique to improve low-level features which uses parallel one-against-all perceptrons to synthesize new features with a higher discrimination power which in turn leads to improved classification and retrieval results. The proposed method can be applied on any database and low-level features as long as some ground-truth information is available. The main merits of the proposed technique are its simplicity and faster computation compared to existing feature synthesis methods. Extensive simulation results show a significant improvement in the features’ discrimination power.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Video, Qatar University
Contributors: Raitoharju, J., Kiranyaz, S., Gabbouj, M.
Number of pages: 15
Pages: 943–957
Publication date: Feb 2018
Peer-reviewed: Yes
Early online date: 29 Jul 2016

Publication information

Journal: Neural Computing and Applications
Volume: 29
Issue number: 4
ISSN (Print): 0941-0643
Ratings: 
  • Scopus rating (2018): CiteScore 4.9 SJR 0.637 SNIP 1.521
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Software
Keywords: Content-based image retrieval and classification, Feature synthesis, Multi-dimensional particle swarm optimization, Multi-layer perceptrons

Bibliographical note

EXT="Kiranyaz, Serkan"

Source: Scopus
Source ID: 84979997953

Research output: Contribution to journalArticleScientificpeer-review

A Dataset for Camera Independent Color Constancy

In this paper, we provide a novel dataset designed for camera independent color constancy research. Camera independence corresponds to the robustness of an algorithm’s performance when run on images of the same scene taken by different cameras. Accordingly, the images in our database correspond to several lab and field scenes each of which is captured by three different cameras with minimal registration errors. The lab scenes are also captured under five different illuminations. The spectral responses of cameras and the spectral power distributions of the lab light sources are also provided, as they may prove beneficial for training future algorithms to achieve color constancy. For a fair evaluation of future methods, we provide guidelines for supervised methods with indicated training, validation and testing partitions. Accordingly, we evaluate two recently proposed convolutional neural network based color constancy algorithms as baselines for future research. As a side contribution, this dataset also includes images taken by a mobile camera with color shading corrected and uncorrected results. This allows research on the effect of color shading as well.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG, Intel Corporation
Contributors: Aytekin, C., Nikkanen, J., Gabbouj, M.
Pages: 530-544
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Image Processing
Volume: 27
Issue number: 2
ISSN (Print): 1057-7149
Ratings: 
  • Scopus rating (2018): CiteScore 12.8 SJR 1.809 SNIP 4.285
Original language: English
ASJC Scopus subject areas: Software, Computer Graphics and Computer-Aided Design
Keywords: Cameras, Color constancy, color shading, illumination estimation, Image color analysis, Lighting, platform independence, Reflectivity, Robustness, Sensitivity, Training
Source: Scopus
Source ID: 85032268285

Research output: Contribution to journalArticleScientificpeer-review

An algebraic approach to reducing the number of variables of incompletely defined discrete functions

In this paper, we consider incompletely defined discrete functions, i.e., Boolean and multiple-valued functions, f : S → {0, 1, . . . , q - 1} where S ⊆ {0, 1, . . . , q - 1}n i.e., the function value is specified only on a certain subset S of the domain of the corresponding completely defined function. We assume the function to be sparse i.e. |S| is 'small' relative to the cardinality of the domain. We show that by embedding the domain {0, 1, . . . , q - 1}n , where n is the number of variables and q is a prime power, in a suitable ring structure, the multiplicative structure of the ring can be used to construct a linear function {0, 1, . . . , q - 1}n → {0, 1, . . . , q - 1}m that is injective on S provided that m > 2 logq |S| + logq (n - 1). In this way we find a linear transform that reduces the number of variables from n to m, and can be used e.g. in implementation of an incompletely defined discrete function by using linear decomposition.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Faculty of Electronics Niš
Contributors: Astola, J., Astola, P., Stanković, R., Tabus, I.
Number of pages: 15
Pages: 239-253
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: Journal of Multiple-Valued Logic and Soft Computing
Volume: 31
Issue number: 3
ISSN (Print): 1542-3980
Ratings: 
  • Scopus rating (2018): CiteScore 1.2 SJR 0.224 SNIP 0.605
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Logic

Bibliographical note

EXT="Stanković, Radomir"

Source: Scopus
Source ID: 85055661435

Research output: Contribution to journalArticleScientificpeer-review

Architectural patterns for microservices: A systematic mapping study

Microservices is an architectural style increasing in popularity. However, there is still a lack of understanding how to adopt a microservice-based architectural style. We aim at characterizing different microservice architectural style patterns and the principles that guide their definition. We conducted a systematic mapping study in order to identify reported usage of microservices and based on these use cases extract common patterns and principles. We present two key contributions. Firstly, we identified several agreed microservice architecture patterns that seem widely adopted and reported in the case studies identified. Secondly, we presented these as a catalogue in a common template format including a summary of the advantages, disadvantages, and lessons learned for each pattern from the case studies. We can conclude that different architecture patterns emerge for different migration, orchestration, storage and deployment settings for a set of agreed principles.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Free University of Bolzano-Bozen
Contributors: Taibi, D., Lenarduzzi, V., Pahl, C.
Number of pages: 12
Pages: 221-232
Publication date: 2018

Host publication information

Title of host publication: CLOSER 2018 - Proceedings of the 8th International Conference on Cloud Computing and Services Science
Publisher: SCITEPRESS
ISBN (Electronic): 9789897582950
ASJC Scopus subject areas: Computer Science (miscellaneous), Software, Computer Science Applications
Keywords: Architectural style, Architecture pattern, Cloud migration, Cloud native, DevOps, Microservices
Source: Scopus
Source ID: 85046716130

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Blind estimation of white Gaussian noise variance in highly textured images

In the paper, a new method of blind estimation of noise variance in a single highly textured image is proposed. An input image is divided into 8x8 blocks and discrete cosine transform (DCT) is performed for each block. A part of 64 DCT coefficients with lowest energy calculated through all blocks is selected for further analysis. For the DCT coefficients, a robust estimate of noise variance is calculated. Corresponding to the obtained estimate, a part of blocks having very large values of local variance calculated only for the selected DCT coefficients are excluded from the further analysis. These two steps (estimation of noise variance and exclusion of blocks) are iteratively repeated three times. For the verification of the proposed method, a new noise-free test image database TAMPERE17 consisting of many highly textured images is designed. It is shown for this database and different values of noise variance from the set {25, 49, 100, 225}, that the proposed method provides approximately two times lower estimation root mean square error than other methods.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Don State Technical University
Contributors: Ponomarenko, M., Gapon, N., Voronin, V., Egiazarian, K.
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Image Processing: Algorithms and Systems XVI
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Blind estimation of noise characteristics, Discrete cosine transform (DCT), Noise free test image database

Bibliographical note

jufoid=84313

Source: Scopus
Source ID: 85052856410

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Combined local and global image enhancement algorithm

We present a new image enhancement algorithm based on combined local and global image processing. The basic idea is to apply α-rooting image enhancement approach for different image blocks. For this purpose, we split image in moving windows on disjoint blocks with different size (8 by 8, 16 by 16, 32 by 32 and, i.e.). The parameter alfa for every block driven through optimization of measure of enhancement (EME). The resulting image is a weighted mean of all processing blocks. This strategy for image enhancement allows getting more contrast image with the following properties: irregular lighting and brightness gradient. Some experimental results are presented to illustrate the performance of the proposed algorithm.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Don State Technical University, College of Staten Island
Contributors: Voronin, V., Semenishchev, E., Ponomarenko, M., Agaian, S.
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Image Processing: Algorithms and Systems XVI
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics

Bibliographical note

jufoid=84313

Source: Scopus
Source ID: 85052861928

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Compression of signs of DCT coefficients for additional lossless compression of JPEG images

One of the main approaches to additional lossless compression of JPEG images is decoding of quantized values of discrete cosine transform (DCT) coefficients and further more effective recompression of the coefficients. Values of amplitudes of DCT coefficients are highly correlated and it is possible to effectively compress them. At the same time, signs of DCT coefficients, which occupy up to 20% of compressed image, are often considered unpredictable. In the paper, a new and effective method for compression of signs of quantized DCT coefficients is proposed. The proposed method takes into account both correlation between DCT coefficients of the same block and correlation between DCT coefficients of neighbor blocks. For each of 64 DCT coefficients, positions of 3 reference coefficients inside the block are determined and stored in the compressed file. Four reference coefficients with fixed positions are used from the neighbor blocks. For all reference coefficients, 15 frequency models to predict signs of a given coefficient are used. All 7 probabilities (that the sign is negative) are mixed by logistic mixing. For test set of JPEG images, we show that the proposed method allows compressing signs of DCT coefficients by 1.1 ⋯ 1.3 times, significantly outperforming nearest analogues.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Kharkiv National Aerospace University
Contributors: Miroshnichenko, O., Ponomarenko, M., Lukin, V., Egiazarian, K.
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Image Processing: Algorithms and Systems XVI
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Discrete cosine transform, JPEG, JPEG additional compression, Sign compression

Bibliographical note

jufoid=84313
EXT="Lukin, Vladimir"

Source: Scopus
Source ID: 85052859716

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Conversion of sparsely-captured light field into alias-free fullparallax multiview content

We propose shearlet decomposition based light field (LF) reconstruction and filtering techniques for mitigating artifacts in the visualized contents of 3D multiview displays. Using the LF reconstruction capability, we first obtain the densely sampled light field (DSLF) of the scene from a sparse set of view images. We design the filter via tiling the Fourier domain of epipolar image by shearlet atoms that are directionally and spatially localized versions of the desired display passband. In this way, it becomes possible to process the DSLF in a depth-dependent manner. That is, the problematic areas in the 3D scene that are outside of the display depth of field (DoF) can be selectively filtered without sacrificing high details in the areas near the display, i.e. inside the DoF. The proposed approach is tested on a synthetic scene and the improvements achieved by means of the quality of the visualized content are verified, where the visualization process is simulated using a geometrical optics model of the human eye.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Electronics and Telecommunication Research Institute (ETRI)
Contributors: Sahin, E., Vagharshakyan, S., Bregovic, R., Lee, G., Gotchev, A.
Number of pages: 5
Pages: 1441-1445
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Stereoscopic Displays and Applications XXIX
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics

Bibliographical note

jufoid=84313

Source: Scopus
Source ID: 85052854954

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Deep p-Fibonacci scattering networks

Recently, the use of neural networks for image classification has become widely spread. Thanks to the availability of increased computational power, better performing architectures have been designed, such as the Deep Neural networks. In this work, we propose a novel image representation framework exploiting the Deep p- Fibonacci scattering network. The architecture is based on the structured p-Fibonacci scattering over graph data. This approach allows to provide good accuracy in classification while reducing the computational complexity. Experimental results demonstrate that the performance of the proposed method is comparable to state-of-the-art unsupervised methods while being computationally more efficient.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, University “Roma Tre”
Contributors: Battisti, F., Carli, M., De Paola, E., Egiazarian, K.
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Image Processing: Algorithms and Systems XVI
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics

Bibliographical note

jufoid=84313
EXT="Battisti, F."
EXT="Carli, M."

Source: Scopus
Source ID: 85052873638

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Fair testing and stubborn sets

Partial order methods alleviate state explosion by considering only a subset of actions in each constructed state. The choice of the subset depends on the properties that the method promises to preserve. Many methods have been developed ranging from deadlock-preserving to CTL(Formula presented.)-preserving and divergence-sensitive branching bisimilarity preserving. The less the method preserves, the smaller state spaces it constructs. Fair testing equivalence unifies deadlocks with livelocks that cannot be exited and ignores the other livelocks. It is the weakest congruence that preserves whether or not the system may enter a livelock that it cannot leave. We prove that a method that was designed for trace equivalence also preserves fair testing equivalence. We demonstrate its effectiveness on a protocol with a connection and data transfer phase. This is the first practical partial order method that deals with a practical fairness assumption.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, University of Augsburg
Contributors: Valmari, A., Vogler, W.
Number of pages: 22
Pages: 589-610
Publication date: 2018
Peer-reviewed: Yes
Early online date: 11 Dec 2017

Publication information

Journal: International Journal on Software Tools for Technology Transfer
ISSN (Print): 1433-2779
Ratings: 
  • Scopus rating (2018): CiteScore 4.8 SJR 0.472 SNIP 1.693
Original language: English
ASJC Scopus subject areas: Software, Information Systems
Keywords: Fair testing equivalence, Fairness, Partial order methods, Progress, Stubborn sets
Electronic versions: 
URLs: 
Source: Scopus
Source ID: 85037686390

Research output: Contribution to journalArticleScientificpeer-review

Federated IoT services leveraging 5G technologies at the edge

The Internet of Things (IoT) ecosystem is evolving towards the deployment of integrated environments, wherein heterogeneous devices pool their capacities together to match wide-ranging user and service requirements. As a consequence, solutions for efficient and synergistic cooperation among objects acquire great relevance. Along this line, this paper focuses on the adoption of the promising MIFaaS (Mobile-IoT-Federation-as-a-Service) paradigm to support delay-sensitive applications for high-end IoT devices in next-to-come fifth generation (5G) environments. MIFaaS fosters the provisioning of IoT services and applications with low-latency requirements by leveraging cooperation among private/public clouds of IoT objects at the edge of the network. A performance assessment of the MIFaaS paradigm in a cellular 5G environment based on both Long Term Evolution (LTE) and the recent Narrowband IoT (NB-IoT) is presented. Obtained results demonstrate that the proposed solution outperforms classic approaches, highlighting significant benefits derived from the joint use of LTE and NB-IoT bandwidths in terms of increased number of successfully delivered IoT services.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Universita degli Studi di Reggio Calabria, Peoples’ Friendship University of Russia
Contributors: Farris, I., Orsino, A., Militano, L., Iera, A., Araniti, G.
Pages: 58-69
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: Ad Hoc Networks
Volume: 68
ISSN (Print): 1570-8705
Ratings: 
  • Scopus rating (2018): CiteScore 7.7 SJR 0.648 SNIP 2.03
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications
Keywords: 5G, IoT, Multi-access edge computing, Narrowband-IoT

Bibliographical note

INT=ELT, "Orsino, A."

Source: Scopus
Source ID: 85030565702

Research output: Contribution to journalArticleScientificpeer-review

How to design gamification? A method for engineering gamified software

Context: Since its inception around 2010, gamification has become one of the top technology and software trends. However, gamification has also been regarded as one of the most challenging areas of software engineering. Beyond traditional software design requirements, designing gamification requires the command of disciplines such as (motivational/behavioral) psychology, game design, and narratology, making the development of gamified software a challenge for traditional software developers. Gamification software inhabits a finely tuned niche of software engineering that seeks for both high functionality and engagement; beyond technical flawlessness, gamification has to motivate and affect users. Consequently, it has also been projected that most gamified software is doomed to fail. Objective: This paper seeks to advance the understanding of designing gamification and to provide a comprehensive method for developing gamified software. Method: We approach the research problem via a design science research approach; firstly, by synthesizing the current body of literature on gamification design methods and by interviewing 25 gamification experts, producing a comprehensive list of design principles for developing gamified software. Secondly, and more importantly, we develop a detailed method for engineering of gamified software based on the gathered knowledge and design principles. Finally, we conduct an evaluation of the artifacts via interviews of ten gamification experts and implementation of the engineering method in a gamification project. Results: As results of the study, we present the method and key design principles for engineering gamified software. Based on the empirical and expert evaluation, the developed method was deemed as comprehensive, implementable, complete, and useful. We deliver a comprehensive overview of gamification guidelines and shed novel insights into the nature of gamification development and design discourse. Conclusion: This paper takes first steps towards a comprehensive method for gamified software engineering.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: TUT Game Lab, Pervasive Computing, University of Duisburg-Essen
Contributors: Morschheuser, B., Hassan, L., Werder, K., Hamari, J.
Pages: 219-237
Publication date: 2018
Peer-reviewed: Yes
Early online date: 2017

Publication information

Journal: Information and Software Technology
Volume: 95
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2018): CiteScore 7.9 SJR 0.615 SNIP 3.085
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Design science research, Game design, Gameful design, Gamification, Persuasive technology, Playfulness, Software engineering
Source: Scopus
Source ID: 85035150495

Research output: Contribution to journalArticleScientificpeer-review

Information Exchange Architecture for Collaborative Industrial Ecosystem

Due to the networked nature of modern industrial business, repeated information exchange activities are necessary. Unfortunately, information exchange is both laborious and expensive with the current communication media, which causes errors and delays. To increase the efficiency of communication, this study introduces an architecture to exchange information in a digitally processable manner in industrial ecosystems. The architecture builds upon commonly agreed business practices and data formats, and an open consortium and information mediators enable it. Following the architecture, a functional prototype has been implemented for a real industrial scenario. This study has its focus on the technical information of equipment, but the architecture concept can also be applied in financing and logistics. Therefore, the concept has potential to completely reform industrial communication.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering, Research group: Automation and Systems Theory, Collaxion Oy
Contributors: Kannisto, P., Hästbacka, D., Marttinen, A.
Pages: 1-16
Publication date: 2018
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: Information Systems Frontiers
ISSN (Print): 1387-3326
Ratings: 
  • Scopus rating (2018): CiteScore 7.6 SJR 0.797 SNIP 2.201
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Information Systems, Computer Networks and Communications
Keywords: Digital business ecosystem, Industrial information management, Lifecycle management, Multi-sided platform, Operations and maintenance, Systems integration
Source: Scopus
Source ID: 85052098014

Research output: Contribution to journalArticleScientificpeer-review

Information models and information exchange in plant-wide monitoring and control of industrial processes

The efficiency of industrial processes depends on how well the processes can be controlled and this affects the quality, use of resources as well as the environmental impact. Advanced monitoring and control solutions for large-scale industrial processes require information from different systems. The challenge in integration is diverse messaging structures and lack of common semantics in exchange of information between related information systems as well as their human operators. This paper provides a comparison of some of the existing standards of the domain defining suitable structures. Based on these, a model for data and event message structures is developed. The approach builds on a separation of concerns keeping the messaging semantics independent of the transport layer. The requirement is to enable also asynchronous communication as adapters are often needed in distributed environments with heterogeneous systems and communication protocols. The developed structures have been found suitable for communicating measurements and events in industrial process settings as shown by case examples.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Automation and Hydraulic Engineering
Contributors: Hästbacka, D., Kannisto, P., Vilkko, M.
Number of pages: 7
Pages: 216-222
Publication date: 2018

Host publication information

Title of host publication: Proceedings of the 10th International Joint Conference on Knowledge Discovery, Knowledge Engineering and Knowledge Management - Volume 3: KMIS : September 18-20, 2018, Seville, Spain
Publisher: SCITEPRESS
ISBN (Electronic): 9789897583308
ASJC Scopus subject areas: Software
Keywords: Data exchange, Industrial processes, Information models, Interoperability

Bibliographical note

Jufo_ID: 73527

Source: Scopus
Source ID: 85059085263

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Is Texture Denoising Efficiency Predictable?

Images of different origin contain textures, and textural features in such regions are frequently employed in pattern recognition, image classification, information extraction, etc. Noise often present in analyzed images might prevent a proper solution of basic tasks in the aforementioned applications and is worth suppressing. This is not an easy task since even the most advanced denoising methods destroy texture in a more or less degree while removing noise. Thus, it is desirable to predict the filtering behavior before any denoising is applied. This paper studies the efficiency of texture image denoising for different noise intensities and several filter types under different visual quality criteria (quality metrics). It is demonstrated that the most efficient existing filters provide very similar results. From the obtained results, it is possible to generalize and employ the prediction strategy earlier proposed for denoising techniques based on the discrete cosine transform. Accuracy of such a prediction is studied and the ways to improve it are considered. Some practical recommendations concerning a decision to undertake whether it is worth applying a filter are given.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Computational Imaging-CI
Contributors: Rubel, O., Lukin, V., Abramov, S., Vozel, B., Pogrebnyak, O., Egiazarian, K.
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: International Journal of Pattern Recognition and Artificial Intelligence
Volume: 32
Issue number: 1
Article number: 1860005
ISSN (Print): 0218-0014
Ratings: 
  • Scopus rating (2018): CiteScore 2.2 SJR 0.304 SNIP 0.718
Original language: English
ASJC Scopus subject areas: Software, Computer Vision and Pattern Recognition, Artificial Intelligence
Keywords: image processing, noise suppression, Texture denoising, visual quality
Electronic versions: 
Source: Scopus
Source ID: 85025804856

Research output: Contribution to journalArticleScientificpeer-review

Making the cloud work for software producers: Linking architecture, operating cost and revenue

Cloud migration is concerned with moving an on-premise software system into the cloud. In this paper, we focus on software producers adopting the cloud to provide their solutions to enterprise customers. Their challenge is to migrate a software product, developed in-house and traditionally delivered on-premise, to an Infrastructure-as-a-Service or Platform-as-a-Service solution, while also mapping an existing traditional licensing model on to a cloud monetization model. The analysis of relevant cost types and factors of cloud computing generate relevant information for the software producers when deciding to adopt cloud computing, and defining software pricing. We present an integrated framework for informing cloud monetization based on operational cost factors for migrating to the cloud and test it in a real-life case study. Differences between basic virtualization of the software product and using fully cloud-native platform services for re-architecting the product in question are discussed.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Dublin City University, Free University of Bolzano-Bozen, Human-Centered Technology (IHTE)
Contributors: Rosati, P., Fowley, F., Pahl, C., Taibi, D., Lynn, T.
Number of pages: 12
Pages: 364-375
Publication date: 2018

Host publication information

Title of host publication: CLOSER 2018 - Proceedings of the 8th International Conference on Cloud Computing and Services Science
Publisher: SCITEPRESS
ISBN (Electronic): 9789897582950
ASJC Scopus subject areas: Computer Science (miscellaneous), Software, Computer Science Applications
Keywords: Architecture migration, Cloud migration, Monetization, Software producer, Total cost of ownership
Source: Scopus
Source ID: 85048894202

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Memory Tampering Attack on Binary GCD Based Inversion Algorithms

In the field of cryptography engineering, implementation-based attacks are a major concern due to their proven feasibility. Fault injection is one attack vector, nowadays a major research line. In this paper, we present how a memory tampering-based fault attack can be used to severely limit the output space of binary GCD based modular inversion algorithm implementations. We frame the proposed attack in the context of ECDSA showing how this approach allows recovering the private key from only one signature, independent of the key size. We analyze two memory tampering proposals, illustrating how this technique can be adapted to different implementations. Besides its application to ECDSA, it can be extended to other cryptographic schemes and countermeasures where binary GCD based modular inversion algorithms are employed. In addition, we describe how memory tampering-based fault attacks can be used to mount a previously proposed fault attack on scenarios that were initially discarded, showing the importance of including memory tampering attacks in the frameworks for analyzing fault attacks and their countermeasures.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Research area: Information security, Universidad Tecnológica de la Habana José Antonio Echeverría, Universidad de Sevilla
Contributors: Aldaya, A. C., Brumley, B. B., Sarmiento, A. J., Sánchez-Solano, S.
Pages: 1-20
Publication date: 2018
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: International Journal of Parallel Programming
ISSN (Print): 0885-7458
Ratings: 
  • Scopus rating (2018): CiteScore 2.4 SJR 0.289 SNIP 0.97
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Information Systems
Keywords: Binary GCD, Bitstream manipulation, ECDSA, Fault attacks, FPGA memory tampering
Electronic versions: 
URLs: 
Source: Scopus
Source ID: 85057616270

Research output: Contribution to journalArticleScientificpeer-review

Methods and tools for denoising of complex-valued images based on block-matching and high order singular value decomposition

Noise suppression in complex-valued data is an important task for a wide class of applications, in particular concerning the phase retrieval in coherent imaging. The approaches based on BM3D techniques are ones of the most successful in the field. In this paper, we propose and develop a new class of BM3Dstyle algorithms, which use high order (3D and 4D) singular value decomposition (HOSVD) for transform design in complex domain. This set of the novel algorithms is implemented as a toolbox In Matlab. This development is produced for various types of the complex-domain sparsity: directly in complex domain, real/imaginary and phase/ amplitude parts of complexvalued variables. The group-wise transform design is combined with the different kinds of thresholding including multivariable Wiener filtering. The toolbox includes iterative and non-iterative novel complex-domain algorithms (filters). The efficiency of the developed algorithms is demonstrated on denoising problems with an additive Gaussian complex-valued noise. A special set of the complex-valued test-images was developed with spatially varying correlated phase and amplitudes imitating data typical for optical interferometry and holography. It is shown that for this class of the test-images the developed algorithms demonstrate the stateof- the-art performance.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing
Contributors: Ponomarenko, M., Katkovnik, V., Egiazarian, K.
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Image Processing: Algorithms and Systems XVI
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Block matching, Complex domain, Higher-order singular value decomposition, Image denoising, Phase imaging, Sparsity

Bibliographical note

jufoid=84313

Source: Scopus
Source ID: 85052877244

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Mixed-integer linear programming approach for global discrete sizing optimization of frame structures

This paper focuses on discrete sizing optimization of frame structures using commercial profile catalogs. The optimization problem is formulated as a mixed-integer linear programming (MILP) problem by including the equations of structural analysis as constraints. The internal forces of the members are taken as continuous state variables. Binary variables are used for choosing the member profiles from a catalog. Both the displacement and stress constraints are formulated such that for each member limit values can be imposed at predefined locations along the member. A valuable feature of the formulation, lacking in most contemporary approaches, is that global optimality of the solution is guaranteed by solving the MILP using branch-and-bound techniques. The method is applied to three design problems: a portal frame, a two-story frame with three load cases and a multiple-bay multiple-story frame. Performance profiles are determined to compare the MILP reformulation method with a genetic algorithm.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Civil Engineering, KU Leuven
Contributors: van Mellaert, R., Mela, K., Tiainen, T., Heinisuo, M., Lombaert, G., Schevenels, M.
Number of pages: 15
Pages: 579–593
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: Structural and Multidisciplinary Optimization
Volume: 57
Issue number: 2
ISSN (Print): 1615-147X
Ratings: 
  • Scopus rating (2018): CiteScore 5.1 SJR 1.835 SNIP 1.887
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Software, Computer Science Applications, Computer Graphics and Computer-Aided Design, Control and Optimization
Keywords: Discrete optimization, Frame structures, Global optimization, Mixed-integer linear programming, Sizing optimization
Source: Scopus
Source ID: 85026724545

Research output: Contribution to journalArticleScientificpeer-review

Modeling and estimation of signal-dependent and correlated noise

The additive white Gaussian noise (AWGN) model is ubiquitous in signal processing. This model is often justified by central-limit theorem (CLT) arguments. However, whereas the CLT may support a Gaussian distribution for the random errors, it does not provide any justification for the assumed additivity and whiteness. As a matter of fact, data acquired in real applications can seldom be described with good approximation by the AWGN model, especially because errors are typically correlated and not additive. Failure to model accurately the noise leads to inaccurate analysis, ineffective filtering, and distortion or even failure in the estimation. This chapter provides an introduction to both signal-dependent and correlated noise and to the relevant models and basic methods for the analysis and estimation of these types of noise. Generic one-parameter families of distributions are used as the essential mathematical setting for the observed signals. The distribution families covered as leading examples include Poisson, mixed Poisson–Gaussian, various forms of signal-dependent Gaussian noise (including multiplicative families and approximations of the Poisson family), as well as doubly censored heteroskedastic Gaussian distributions. We also consider various forms of noise correlation, encompassing pixel and readout cross-talk, fixed-pattern noise, column/row noise, etc., as well as related issues like photo-response and gain nonuniformity. The introduced models and methods are applicable to several important imaging scenarios and technologies, such as raw data from digital camera sensors, various types of radiation imaging relevant to security and to biomedical imaging.

General information

Publication status: Published
MoE publication type: A3 Part of a book or another research book
Organisations: Signal Processing, Research group: Signal and Image Restoration-RST, University of São Paulo
Contributors: Azzari, L., Borges, L. R., Foi, A.
Number of pages: 36
Pages: 1-36
Publication date: 2018

Host publication information

Title of host publication: Denoising of Photographic Images and Video : Fundamentals, Open Challenges and New Trends
Publisher: SPRINGER-VERLAG LONDON LTD
ISBN (Print): 978-3-319-96028-9

Publication series

Name: Advances in Computer Vision and Pattern Recognition
ISSN (Print): 2191-6586
ISSN (Electronic): 2191-6594
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
URLs: 
Source: Scopus
Source ID: 85053409603

Research output: Chapter in Book/Report/Conference proceedingChapterScientificpeer-review

Multisensor Time–Frequency Signal Processing MATLAB package: An analysis tool for multichannel non-stationary data

The Multisensor Time–FrequencySignal Processing (MTFSP) MATLAB package is an analysis tool for multichannel non-stationary signals collected from an array of sensors. By combining array signal processing for non-stationary signals and multichannel high resolution time–frequency methods, MTFSP enables applications such as cross-channel causality relationships, automated component separation and direction of arrival estimation, using multisensor time–frequency distributions (MTFDs). MTFSP can address old and new applications such as: abnormality detection in biomedical signals, source localization in wireless communications or condition monitoring and fault detection in industrial plants. It allows e.g. the reproduction of the results presented in Boashash and Aïssa-El-Bey (in press) [2].

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: University of Queensland
Contributors: Boashash, B., Aïssa-El-Bey, A., Al-Sa'd, M. F.
Pages: 53-58
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: SoftwareX
Volume: 8
ISSN (Print): 2352-7110
Ratings: 
  • Scopus rating (2018): CiteScore 10.8 SJR 4.539 SNIP 5.206
Original language: English
ASJC Scopus subject areas: Software, Computer Science Applications
Keywords: Automated component separation, Blind source separation, Cross-channel causality analysis, Direction of arrival, Multisensor time–frequency analysis, Non-stationary array processing
Source: Scopus
Source ID: 85041238142

Research output: Contribution to journalArticleScientificpeer-review

Multi-view predictive latent space learning

In unsupervised circumstances, multi-view learning seeks a shared latent representation by taking the consensus and complementary principles into account. However, most existing multi-view unsupervised learning approaches do not explicitly lay stress on the predictability of the latent space. In this paper, we propose a novel multi-view predictive latent space learning (MVP) model and apply it to multi-view clustering and unsupervised dimension reduction. The latent space is forced to be predictive by maximizing the correlation between the latent space and feature space of each view. By learning a multi-view graph with adaptive view-weight learning, MVP effectively combines the complementary information from multi-view data. Experimental results on benchmark datasets show that MVP outperforms the state-of-the-art multi-view clustering and unsupervised dimension reduction algorithms.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Tianjin University
Contributors: Yuan, J., Gao, K., Zhu, P., Egiazarian, K.
Publication date: 2018
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: Pattern Recognition Letters
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2018): CiteScore 5.8 SJR 0.662 SNIP 1.729
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
Keywords: Multi-view learning, Predictive latent space learning, Unsupervised clustering, Unsupervised dimension reduction
Source: Scopus
Source ID: 85049094619

Research output: Contribution to journalArticleScientificpeer-review

On the degeneracy of the Randić entropy and related graph measures

Numerous quantitative graph measures have been defined and applied in various disciplines. Such measures may be differentiated according to whether they are information-theoretic or non-information-theoretic. In this paper, we examine an important property of Randić entropy, an information-theoretic measure, and examine some related graph measures based on random roots. In particular, we investigate the degeneracy of these structural graph measures and discuss numerical results. Finally, we draw some conclusions about the measures’ applicability to deterministic and non-deterministic networks.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Computational Medicine and Statistical Learning Laboratory (CMSL), Research group: Predictive Society and Data Analytics (PSDA), University of Applied Sciences Upper Austria, School of Management, Nankai University, Hall in Tyrol, The City College of New York (CUNY), Production and Operations Management, Tianjin University of Technology
Contributors: Dehmer, M., Chen, Z., Mowshowitz, A., Jodlbauer, H., Emmert-Streib, F., Shi, Y., Tripathi, S., Xia, C.
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2018): CiteScore 10.4 SJR 1.62 SNIP 2.744
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Data science, Graphs, Networks, Quantitative graph theory, Structural graph measures, Structural network analysis

Bibliographical note

EXT="Tripathi, Shailesh"

Source: Scopus
Source ID: 85057760552

Research output: Contribution to journalArticleScientificpeer-review

Probabilistic saliency estimation

In this paper, we model the salient object detection problem under a probabilistic framework encoding the boundary connectivity saliency cue and smoothness constraints into an optimization problem. We show that this problem has a closed form global optimum solution, which estimates the salient object. We further show that along with the probabilistic framework, the proposed method also enjoys a wide range of interpretations, i.e. graph cut, diffusion maps and one-class classification. With an analysis according to these interpretations, we also find that our proposed method provides approximations to the global optimum to another criterion that integrates local/global contrast and large area saliency cues. The proposed unsupervised approach achieves mostly leading performance compared to the state-of-the-art unsupervised algorithms over a large set of salient object detection datasets including around 17k images for several evaluation metrics. Furthermore, the computational complexity of the proposed method is favorable/comparable to many state-of-the-art unsupervised techniques.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG
Contributors: Aytekin, C., Iosifidis, A., Gabbouj, M.
Number of pages: 14
Pages: 359-372
Publication date: 2018
Peer-reviewed: Yes
Early online date: 20 Sep 2017

Publication information

Journal: Pattern Recognition
Volume: 74
ISSN (Print): 0031-3203
Ratings: 
  • Scopus rating (2018): CiteScore 10.4 SJR 1.363 SNIP 3.211
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
Keywords: Diffusion maps, One-class classification, Probabilistic model, Saliency, Salient object detection, Spectral graph cut
Source: Scopus
Source ID: 85032271491

Research output: Contribution to journalArticleScientificpeer-review

Reduction of variables of index generation functions using linear and quadratic transformations

In many applications in communication, data retrieval and processing, digital system design, and related areas, incompletely specified switching (Boolean or multiple-valued) functions are encountered. A particular class of highly incompletely specified functions are the so-called index generation functions, which being defined on a small fraction of input combinations, often do not require all the variables to be represented. Reducing the variables of index generation functions is an important task, since they are used mainly in real-time applications and compactness of their representations influences performances of related systems. One approach towards reducing the number of variables in index generation functions are linear transformations meaning that initial variables are replaced by their linear combinations. A drawback is that finding an optimal transformation can be difficult. Therefore, in this paper, we first formulate the problem of finding a good linear transformation by using linear subspaces. This formulation serves as a basis to propose non-linear (polynomial) transformations to reduce the number of variables in index generation functions.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Faculty of Electronics
Contributors: Astola, H., Stanković, R., Astola, J.
Number of pages: 16
Pages: 255-270
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: Journal of Multiple-Valued Logic and Soft Computing
Volume: 31
Issue number: 3
ISSN (Print): 1542-3980
Ratings: 
  • Scopus rating (2018): CiteScore 1.2 SJR 0.224 SNIP 0.605
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Logic
Keywords: Index generation function, Linear transformation, Non-linear transformation, Reed-Muller expression

Bibliographical note

EXT="Stanković, Radomir"

Source: Scopus
Source ID: 85055671990

Research output: Contribution to journalArticleScientificpeer-review

Robust linearized combined metrics of image visual quality

Existing full-reference metrics still do not provide a desirable degree of adequacy to a human visual perception, for evaluation of images with different types and levels of distortions. One reason for this is that it is difficult to incorporate the peculiarities of human visual system in the metrics design. In this paper, a robust approach to full-reference metrics' design is proposed, based on a combination of several existing full-reference metrics. A preliminary linearization (fitting) of the dependence of MOS with respect to the components metrics is performed in order to compensate shortcomings of each component. The proposed method is tested on several known databases, and demonstrate better performance than existing metrics.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Kharkiv National Aerospace University
Contributors: Ieremeiev, O., Lukin, V., Ponomarenko, N., Egiazarian, K.
Publication date: 2018

Host publication information

Title of host publication: Electronic Imaging : Image Processing: Algorithms and Systems XVI
Publisher: Society for Imaging Science and Technology
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Science Applications, Human-Computer Interaction, Software, Electrical and Electronic Engineering, Atomic and Molecular Physics, and Optics
Keywords: Combined metrics, Full-reference metrics, Image visual quality assessment, Robust metrics

Bibliographical note

jufoid=84313
EXT="Ponomarenko, Nikolay"
EXT="Lukin, Vladimir"

Source: Scopus
Source ID: 85052901571

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Time-of-Flight Range Measurement in Low-sensing Environment: Noise Analysis and Complex-domain Non-local Denoising

In this work, we deal with the problem of denoising 3D scene range measurements acquired by Time-of-flight (ToF) range sensors and composed in the form of 2D image-like depth maps. We address the specific case of ToF low-sensing environment (LSE). Such environment is set by low-light sensing conditions, low-power hardware requirements, and low-reflectivity scenes. We demonstrate that data captured by a device in such mode can be effectively post-processed in order to reach the same measurement accuracy as if the device was working in normal operating mode. In order to achieve this, we first present an elaborated analysis of noise properties of ToF data sensed in LSE and verify the derived noise models by empirical measurements. Then, we develop a related novel non-local denoising approach working in complex domain and demonstrate its superiority against the state of the art for data acquired by an off-the-shelf ToF device.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: 3D MEDIA, Research group: 3D MEDIA
Contributors: Georgiev, M., Bregovic, R., Gotchev, A.
Publication date: 2018
Peer-reviewed: Yes
Early online date: 15 Feb 2018

Publication information

Journal: IEEE Transactions on Image Processing
Volume: 27
Issue number: 6
ISSN (Print): 1057-7149
Ratings: 
  • Scopus rating (2018): CiteScore 12.8 SJR 1.809 SNIP 4.285
Original language: English
ASJC Scopus subject areas: Software, Computer Graphics and Computer-Aided Design
Keywords: 3D, Delays, denoising, Filtering, Harmonic analysis, low-sensing environment, Noise measurement, noise model, Noise reduction, Phase measurement, phase-wrap, range sensing, Sensors, Time-of-Flight (ToF)
Source: Scopus
Source ID: 85042184733

Research output: Contribution to journalArticleScientificpeer-review

How developers perceive smells in source code: A replicated study

Context. In recent years, smells, also referred to as bad smells, have gained popularity among developers. However, it is still not clear how harmful they are perceived from the developers’ point of view. Many developers talk about them, but only few know what they really are, and even fewer really take care of them in their source code. Objective. The goal of this work is to understand the perceived criticality of code smells both in theory, when reading their description, and in practice. Method. We executed an empirical study as a differentiated external replication of two previous studies. The studies were conducted as surveys involving only highly experienced developers (63 in the first study and 41 in the second one). First the perceived criticality was analyzed by proposing the description of the smells, then different pieces of code infected by the smells were proposed, and finally their ability to identify the smells in the analyzed code was tested. Results. According to our knowledge, this is the largest study so far investigating the perception of code smells with professional software developers. The results show that developers are very concerned about code smells in theory, nearly always considering them as harmful or very harmful (17 out of 23 smells). However, when they were asked to analyze an infected piece of code, only few infected classes were considered harmful and even fewer were considered harmful because of the smell. Conclusions. The results confirm our initial hypotheses that code smells are perceived as more critical in theory but not as critical in practice.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Free University of Bolzano-Bozen, Free University of Bozen-Bolzano
Contributors: Taibi, D., Janes, A., Lenarduzzi, V.
Number of pages: 13
Pages: 223-235
Publication date: 1 Dec 2017
Peer-reviewed: Yes

Publication information

Journal: Information and Software Technology
Volume: 92
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2017): CiteScore 7.2 SJR 0.581 SNIP 2.913
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Antipatterns, Bad smells, Code smells, Refactoring, Software maintenance
Source: Scopus
Source ID: 85028762206

Research output: Contribution to journalArticleScientificpeer-review

Multilinear class-specific discriminant analysis

There has been a great effort to transfer linear discriminant techniques that operate on vector data to high-order data, generally referred to as Multilinear Discriminant Analysis (MDA) techniques. Many existing works focus on maximizing the inter-class variances to intra-class variances defined on tensor data representations. However, there has not been any attempt to employ class-specific discrimination criteria for the tensor data. In this paper, we propose a multilinear subspace learning technique suitable for applications requiring class-specific tensor models. The method maximizes the discrimination of each individual class in the feature space while retains the spatial structure of the input. We evaluate the efficiency of the proposed method on two problems, i.e. facial image analysis and stock price prediction based on limit order book data.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Aarhus Universitet, Laboratory of Signal Processing
Contributors: Thanh Tran, D., Gabbouj, M., Iosifidis, A.
Number of pages: 6
Pages: 131-136
Publication date: 1 Dec 2017
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 100
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2017): CiteScore 5.5 SJR 0.662 SNIP 1.605
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
Keywords: Class-specific discriminant learning, Face verification, Multilinear discriminant analysis, Stock price prediction

Bibliographical note

INT=sgn,"Thanh Tran, Dat"

Source: Scopus
Source ID: 85032300703

Research output: Contribution to journalArticleScientificpeer-review

Quantitative Graph Theory: A new branch of graph theory and network science

In this paper, we describe some highlights of the new branch QUANTITATIVE GRAPH THEORY and explain its significant different features compared to classical graph theory. The main goal of quantitative graph theory is the structural quantification of information contained in complex networks by employing a measurement approach based on numerical invariants and comparisons. Furthermore, the methods as well as the networks do not need to be deterministic but can be statistic. As such this complements the field of classical graph theory, which is descriptive and deterministic in nature. We provide examples of how quantitative graph theory can be used for novel applications in the context of the overarching concept network science.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: Computational Medicine and Statistical Learning Laboratory (CMSL), Faculty of Biomedical Sciences and Engineering, BioMediTech, Research group: Predictive Society and Data Analytics (PSDA), Nankai University
Contributors: Dehmer, M., Emmert-Streib, F., Shi, Y.
Number of pages: 6
Pages: 575-580
Publication date: 1 Dec 2017
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 418-419
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2017): CiteScore 10 SJR 1.635 SNIP 2.304
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Theoretical Computer Science, Software, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Data Science, Graphs, Networks, Quantitative Graph Theory, Statistics
Source: Scopus
Source ID: 85027400753

Research output: Contribution to journalArticleScientificpeer-review

Sparse approximations in complex domain based on BM3D modeling

In this paper the concept of sparsity for complex-valued variables is introduced in the following three types: directly in complex domain and for two real-valued pairs phase/amplitude and real/imaginary parts of complex variables. The nonlocal block-matching technique is used for sparsity implementation and filter design for each type of sparsity. These filters are complex domain generalizations of the Block Matching 3D collaborative (BM3D) filter based on the high-order singular value decomposition (HOSVD) in order to generate group-wise adaptive analysis/synthesis transforms. Complex domain denoising is developed and studied as a test-problem for comparison of the designed filters as well as the different types of sparsity modeling.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Computational Imaging-CI
Contributors: Katkovnik, V., Ponomarenko, M., Egiazarian, K.
Number of pages: 13
Pages: 96-108
Publication date: 1 Dec 2017
Peer-reviewed: Yes

Publication information

Journal: Signal Processing
Volume: 141
ISSN (Print): 0165-1684
Ratings: 
  • Scopus rating (2017): CiteScore 7.1 SJR 0.94 SNIP 1.974
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Software, Signal Processing, Computer Vision and Pattern Recognition, Electrical and Electronic Engineering
Keywords: Block matching, Complex domain, Denoising, Elsevier article, Phase imaging, Sample document, Sparsity
Source: Scopus
Source ID: 85020311730

Research output: Contribution to journalArticleScientificpeer-review

Multi-factor authentication for wearables: Configuring system parameters with risk function

The users of today are already about to enter the era of highly integrated modern wearable devices-the time when smart accessorieswill, in turn, push aside regular Smartphones and Tablets bringinga variety of new security challenges. The number of simultaneously used bio-sensors, both integrated into smart wearables andconnected over wireless interfaces, allows novel opportunities forMulti-factor Authentication (MFA) of the user. flis manuscriptproposes a solution for conflguring the MFA based on the averagedirect and indirect losses risk analysis. the example applicationof Bayesian function for MFA presents the applicability of the proposed framework for the utilization with wearables.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Electronics and Communications Engineering, ITMO University, St. Petersburg State University of Aerospace Instrumentation
Contributors: Bezzateev, S., Afanasyeva, A., Voloshina, N., Ometov, A.
Publication date: 13 Nov 2017

Host publication information

Title of host publication: Proceedings of the 2nd International Conference on Advanced Wireless Information, Data, and Communication Technologies, AWICT 2017
Publisher: ACM
ISBN (Electronic): 9781450353106
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Information security, Multi-factor authentication, Risk function, Wearables
Source: Scopus
Source ID: 85045304145

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Big Media Data Analysis

In this editorial a short introduction to the special issue on Big Media Data Analysis is given. The scope of this Editorial is to briefly present methodologies, tasks and applications of big media data analysis and to introduce the papers of the special issue. The special issue includes six papers that span various media analysis application areas like generic image description, medical image and video analysis, distance calculation acceleration and data collection.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG, Aarhus Universitet, University of Milan Bicocca, Department of Informatics, Aristotle University of Thessaloniki
Contributors: Iosifidis, A., Tefas, A., Pitas, I., Gabbouj, M.
Number of pages: 4
Pages: 105-108
Publication date: 1 Nov 2017
Peer-reviewed: Yes

Publication information

Journal: Signal Processing: Image Communication
Volume: 59
ISSN (Print): 0923-5965
Ratings: 
  • Scopus rating (2017): CiteScore 4.6 SJR 0.551 SNIP 1.512
Original language: English
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Electrical and Electronic Engineering
Keywords: Big Media Data, Data analytics, Deep learning, Machine learning, Statistical learning

Bibliographical note

EXT="Tefas, Anastasios"

Source: Scopus
Source ID: 85033445526

Research output: Contribution to journalEditorialScientificpeer-review

Gamified crowdsourcing: Conceptualization, literature review, and future agenda

Two parallel phenomena are gaining attention in human–computer interaction research: gamification and crowdsourcing. Because crowdsourcing's success depends on a mass of motivated crowdsourcees, crowdsourcing platforms have increasingly been imbued with motivational design features borrowed from games; a practice often called gamification. While the body of literature and knowledge of the phenomenon have begun to accumulate, we still lack a comprehensive and systematic understanding of conceptual foundations, knowledge of how gamification is used in crowdsourcing, and whether it is effective. We first provide a conceptual framework for gamified crowdsourcing systems in order to understand and conceptualize the key aspects of the phenomenon. The paper's main contributions are derived through a systematic literature review that investigates how gamification has been examined in different types of crowdsourcing in a variety of domains. This meticulous mapping, which focuses on all aspects in our framework, enables us to infer what kinds of gamification efforts are effective in different crowdsourcing approaches as well as to point to a number of research gaps and lay out future research directions for gamified crowdsourcing systems. Overall, the results indicate that gamification has been an effective approach for increasing crowdsourcing participation and the quality of the crowdsourced work; however, differences exist between different types of crowdsourcing: the research conducted in the context of crowdsourcing of homogenous tasks has most commonly used simple gamification implementations, such as points and leaderboards, whereas crowdsourcing implementations that seek diverse and creative contributions employ gamification with a richer set of mechanics.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: TUT Game Lab, Pervasive Computing, Robert Bosch GmbH, Karlsruhe Institute of Technology, Insitute for Technical Physics, Germany, Gamification Group
Contributors: Morschheuser, B., Hamari, J., Koivisto, J., Maedche, A.
Number of pages: 18
Pages: 26-43
Publication date: 1 Oct 2017
Peer-reviewed: Yes

Publication information

Journal: International Journal of Human-Computer Studies
Volume: 106
ISSN (Print): 1071-5819
Ratings: 
  • Scopus rating (2017): CiteScore 5.9 SJR 0.605 SNIP 2.146
Original language: English
ASJC Scopus subject areas: Human Factors and Ergonomics, Software, Education, Engineering(all), Human-Computer Interaction, Hardware and Architecture
Keywords: Crowdsourcing, Gamification, Human computation, Literature review, Persuasive technology, Research agenda
Source: Scopus
Source ID: 85019568466

Research output: Contribution to journalArticleScientificpeer-review

Highly unique network descriptors based on the roots of the permanental polynomial

In this paper, we examine the zeros of permanental polynomials as highly unique network descriptors. We employ exhaustively generated networks and demonstrate that our defined graph measures based on the moduli of the zeros of permanental polynomials are quite efficient when distinguishing graphs structurally. In this work, we continue with a line of research that relates to the search of almost complete graph invariants. These highly unique network measures may serve as a powerful tool for tackling graph isomorphism.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Computational Medicine and Statistical Learning Laboratory (CMSL), BioMediTech, Research group: Predictive Society and Data Analytics (PSDA), Institute for Bioinformatics and Translational Research, Laboratory of Biosystem Dynamics, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Universität der Bundeswehr München, Nankai University, Babes-Bolyai University
Contributors: Dehmer, M., Emmert-Streib, F., Hu, B., Shi, Y., Stefu, M., Tripathi, S.
Number of pages: 6
Pages: 176-181
Publication date: 1 Oct 2017
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 408
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2017): CiteScore 10 SJR 1.635 SNIP 2.304
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Theoretical Computer Science, Software, Computer Science Applications, Information Systems and Management, Artificial Intelligence
Keywords: Data science, Graphs, Networks, Quantitative graph theory, Statistics
Source: Scopus
Source ID: 85018769218

Research output: Contribution to journalArticleScientificpeer-review

Predicting academic success based on learning material usage

In this work, we explore students' usage of online learning material as a predictor of academic success. In the context of an introductory programming course, we recorded the amount of time that each element such as a text paragraph or an image was visible on the students' screen. Then, we applied machine learning methods to study to what extent material usage predicts course outcomes. Our results show that the time spent with each paragraph of the online learning material is a moderate predictor of student success even when corrected for student time-on-task, and that the information can be used to identify at-risk students. The predictive performance of the models is dependent on the quantity of data, and the predictions become more accurate as the course progresses. In a broader context, our results indicate that course material usage can be used to predict academic success, and that such data can be collected in-situ with minimal interference to the students' learning process.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Software engineering, University of Helsinki
Contributors: Leppänen, L., Leinonen, J., Ihantola, P., Hellas, A.
Number of pages: 6
Pages: 13-18
Publication date: 27 Sep 2017

Host publication information

Title of host publication: SIGITE 2017 - Proceedings of the 18th Annual Conference on Information Technology Education
Publisher: ACM
ISBN (Electronic): 9781450351003
ASJC Scopus subject areas: Computational Theory and Mathematics, Artificial Intelligence, Computer Science Applications, Software
Keywords: Academic success prediction, Educational data mining, Element-level web logs, Online learning materials, Web log mining
Source: Scopus
Source ID: 85037111531

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Architecting liquid software

The Liquid Software metaphor refers to software that can operate seamlessly across multiple devices owned by one or multiple users. Liquid Software applications can take advantage of the computing, storage and communication resources available on all the devices owned by the user. Liquid Software applications can also dynamically migrate from one device to another, following the user’s attention and usage context. The key design goal in Liquid Software development is to minimize the additional efforts arising from multiple device ownership (e.g., installation, synchronization and general maintenance of personal computers, smartphones, tablets, home and car displays, and wearable devices), while keeping the users in full control of their devices, applications and data. In this paper we present the design space for Liquid Software, categorizing and discussing the most important architectural dimensions and technical choices. We also provide an introduction and comparison of two frameworks implementing Liquid Software capabilities in the context of the World Wide Web.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Università della Svizzera Italiana, University of Helsinki, Nokia Technologies Oy
Contributors: Gallidabino, A., Pautasso, C., Mikkonen, T., Systä, K., Voutilainen, J., Taivalsaari, A.
Number of pages: 38
Pages: 433-470
Publication date: 1 Sep 2017
Peer-reviewed: Yes

Publication information

Journal: Journal of Web Engineering
Volume: 16
Issue number: 5-6
ISSN (Print): 1540-9589
Ratings: 
  • Scopus rating (2017): CiteScore 1.1 SJR 0.157 SNIP 0.455
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Networks and Communications
Keywords: Design space, Liquid software, Multi-device programming, Multiple device ownership, Software architecture

Bibliographical note

EXT="Mikkonen, Tommi"
EXT="Taivalsaari, Antero"

Source: Scopus
Source ID: 85020531917

Research output: Contribution to journalArticleScientificpeer-review

Comparison of time metrics in programming

Research on the indicators of student performance in introductory programming courses has traditionally focused on individual metrics and specific behaviors. These metrics include the amount of time and the quantity of steps such as code compilations, the number of completed assignments, and metrics that one cannot acquire from a programming environment. However, the differences in the predictive powers of different metrics and the cross-metric correlations are unclear, and thus there is no generally preferred metric of choice for examining time on task or effort in programming. In this work, we contribute to the stream of research on student time on task indicators through the analysis of a multi-source dataset that contains information about students' use of a programming environment, their use of the learning material as well as self-reported data on the amount of time that the students invested in the course and per-Assignment perceptions on workload, educational value and difficulty. We compare and contrast metrics from the dataset with course performance. Our results indicate that traditionally used metrics from the same data source tend to form clusters that are highly correlated with each other, but correlate poorly with metrics from other data sources. Thus, researchers should utilize multiple data sources to gain a more accurate picture of students' learning.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Software engineering, University of Helsinki
Contributors: Leinonen, J., Leppänen, L., Ihantola, P., Hellas, A.
Number of pages: 9
Pages: 200-208
Publication date: 14 Aug 2017

Host publication information

Title of host publication: ICER 2017 - Proceedings of the 2017 ACM Conference on International Computing Education Research
Publisher: ACM
ISBN (Electronic): 9781450349680
ASJC Scopus subject areas: Computational Theory and Mathematics, Computer Science Applications, Software, Education
Source: Scopus
Source ID: 85030162903

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Hardware design methodology using lightweight dataflow and its integration with low power techniques

Dataflow models of computation are capable of providing high-level descriptions for hardware and software components and systems, facilitating efficient processes for system-level design. The modularity and parallelism of dataflow representations make them suitable for key aspects of design exploration and optimization, such as efficient scheduling, task synchronization, memory and power management. The lightweight dataflow (LWDF) programming methodology provides an abstract programming model that supports dataflow-based design of signal processing hardware and software components and systems. Due to its formulation in terms of abstract application programming interfaces, the LWDF methodology can be integrated with a wide variety of simulation- and implementation-oriented languages, and can be targeted across different platforms, which allows engineers to integrate dataflow modeling approaches relatively easily into existing design processes. Previous work on LWDF techniques has emphasized their application to DSP software implementation (e.g., through integration with C and CUDA). In this paper, we efficiently integrate the LWDF methodology with hardware description languages (HDLs), and we apply this HDL-integrated form of the methodology to develop efficient methods for low power DSP hardware implementation. The effectiveness of the proposed LWDF-based hardware design methodology is demonstrated through a case study of a deep neural network application for vehicle classification.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Signal Processing, Research group: Vision, Research area: Computer engineering, Dept. of Electrical and Electronic Engineering, University of Maryland, PolComIng - Information Engineering Unit
Contributors: Fanni, T., Li, L., Viitanen, T., Sau, C., Xie, R., Palumbo, F., Raffo, L., Huttunen, H., Takala, J., Bhattacharyya, S. S.
Number of pages: 15
Pages: 15-29
Publication date: 1 Aug 2017
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems Architecture
Volume: 78
ISSN (Print): 1383-7621
Ratings: 
  • Scopus rating (2017): CiteScore 3 SJR 0.255 SNIP 1.274
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture
Keywords: Clock gating, Dataflow, Deep neural networks, Digital systems design, Globally asynchronous locally synchronous, Low power design, Signal processing

Bibliographical note

INT=tie,"Xie, Renjie"

Source: Scopus
Source ID: 85020917888

Research output: Contribution to journalArticleScientificpeer-review

Multi-robot active information gathering with periodic communication

A team of robots sharing a common goal can benefit from coordination of the activities of team members, helping the team to reach the goal more reliably or quickly. We address the problem of coordinating the actions of a team of robots with periodic communication capability executing an information gathering task. We cast the problem as a multi-agent optimal decision-making problem with an information theoretic objective function. We show that appropriate techniques for solving decentralized partially observable Markov decision processes (Dec-POMDPs) are applicable in such information gathering problems. We quantify the usefulness of coordinated information gathering through simulation studies, and demonstrate the feasibility of the method in a real-world target tracking domain.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Automation and Hydraulic Engineering, Department of Informatics, Centre for Structural Systems Biology
Contributors: Lauri, M., Heinänen, E., Frintrop, S.
Number of pages: 6
Pages: 851-856
Publication date: 21 Jul 2017

Host publication information

Title of host publication: ICRA 2017 - IEEE International Conference on Robotics and Automation
Publisher: IEEE
ISBN (Electronic): 9781509046331
ASJC Scopus subject areas: Control and Systems Engineering, Software, Artificial Intelligence, Electrical and Electronic Engineering

Bibliographical note

EXT="Lauri, Mikko"

Source: Scopus
Source ID: 85027996313

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Robustifying correspondence based 6D object pose estimation

We propose two methods to robustify point correspondence based 6D object pose estimation. The first method, curvature filtering, is based on the assumption that low curvature regions provide false matches, and removing points in these regions improves robustness. The second method, region pruning, is more general by making no assumptions about local surface properties. Our region pruning segments a model point cloud into cluster regions and searches good region combinations using a validation set. The robustifying methods are general and can be used with any correspondence based method. For the experiments, we evaluated three correspondence selection methods, Geometric Consistency (GC) [1], Hough Grouping (HG) [2] and Search of Inliers (SI) [3] and report systematic improvements for their robustified versions with two distinct datasets.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Mechanical Engineering and Industrial Systems, Research group: Vision, University of Southern Denmark
Contributors: Hietanen, A., Halme, J., Buch, A. G., Latokartano, J., Kamarainen, J.
Number of pages: 7
Pages: 739-745
Publication date: 21 Jul 2017

Host publication information

Title of host publication: ICRA 2017 - IEEE International Conference on Robotics and Automation
Publisher: IEEE
ISBN (Electronic): 9781509046331
ASJC Scopus subject areas: Control and Systems Engineering, Software, Artificial Intelligence, Electrical and Electronic Engineering
Electronic versions: 
Source: Scopus
Source ID: 85028009977

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A convolutional neural network approach for acoustic scene classification

This paper presents a novel application of convolutional neural networks (CNNs) for the task of acoustic scene classification (ASC). We here propose the use of a CNN trained to classify short sequences of audio, represented by their log-mel spectrogram. We also introduce a training method that can be used under particular circumstances in order to make full use of small datasets. The proposed system is tested and evaluated on three different ASC datasets and compared to other state-of-the-art systems which competed in the 'Detection and Classification of Acoustic Scenes and Events' (DCASE) challenges held in 20161 and 2013. The best accuracy scores obtained by our system on the DCASE 2016 datasets are 79.0% (development) and 86.2% (evaluation), which constitute a 6.4% and 9% improvements with respect to the baseline system. Finally, when tested on the DCASE 2013 evaluation dataset, the proposed system manages to reach a 77.0% accuracy, improving by 1% the challenge winner's score.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Audio research group - ARG, Department of Information Engineering
Contributors: Valenti, M., Squartini, S., Diment, A., Parascandolo, G., Virtanen, T.
Number of pages: 8
Pages: 1547-1554
Publication date: 30 Jun 2017

Host publication information

Title of host publication: 2017 International Joint Conference on Neural Networks, IJCNN 2017
Publisher: IEEE
ISBN (Electronic): 9781509061815
ASJC Scopus subject areas: Software, Artificial Intelligence
Electronic versions: 

Bibliographical note

jufoid=58177

Source: Scopus
Source ID: 85031008536

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Analyzing Forty years of software maintenance models

Software maintenance has dramatically evolved in the last four decades, to cope with the continuously changing software development models, and programming languages and adopting increasingly advanced prediction models. In this work, we present the initial results of a Systematic Literature Review (SLR), highlighting the evolution of the metrics and models adopted in the last forty years.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Innopolis University, Former organisation of the author
Contributors: Lenarduzzi, V., Sillitti, A., Taibi, D.
Publication date: 30 Jun 2017

Host publication information

Title of host publication: Proceedings - 2017 IEEE/ACM 39th International Conference on Software Engineering Companion, ICSE-C 2017
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 7965284
ISBN (Electronic): 9781538615898
ASJC Scopus subject areas: Software, Safety, Risk, Reliability and Quality
Keywords: Software Maintenance, Systematic Literature Review
Source: Scopus
Source ID: 85026754322

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Class-specific kernel discriminant analysis based on Cholesky decomposition

In this paper we describe a method for nonlinear class-specific discriminant learning that is based on Cholesky Decomposition. We show that the optimization problem solved in Class-Specific Kernel Discriminant Analysis is equivalent to that of Low-Rank Kernel Regression using training data independent target vectors. This connection allows us to devise a new Class-Specific Kernel Discriminant Analysis method that can be trained by exploiting fast linear system approaches, like the Cholesky decomposition. We verify our analysis in publicly available verification problems designed for human action recognition.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing
Contributors: Iosifidis, A., Gabbouj, M.
Number of pages: 6
Pages: 1141-1146
Publication date: 30 Jun 2017

Host publication information

Title of host publication: 2017 International Joint Conference on Neural Networks, IJCNN 2017
Publisher: IEEE
ISBN (Electronic): 9781509061815
ASJC Scopus subject areas: Software, Artificial Intelligence

Bibliographical note

jufoid=58177

Source: Scopus
Source ID: 85031037603

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

DevOps in regulated software development: Case medical devices

DevOps and continuous development are getting popular in the software industry. Adopting these modern approaches in regulatory environments, such as medical device software, is not straightforward because of the demand for regulatory compliance. While DevOps relies on continuous deployment and integration, regulated environments require strict audits and approvals before releases. Therefore, the use of modern development approaches in regulatory environments is rare, as is the research on the topic. However, as software is more and more predominant in medical devices, modern software development approaches become attractive. This paper discusses the fit of DevOps for regulated medical device software development. We examine two related standards, IEC 62304 and IEC 82304-1, for obstacles and benefits of using DevOps for medical device software development. We found these standards to set obstacles for continuous delivery and integration. Respectively, development tools can help fulfilling the requirements of traceability and documentation of these standards.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, University of Central Lancashire, University of Helsinki
Contributors: Laukkarinen, T., Kuusinen, K., Mikkonen, T.
Number of pages: 4
Pages: 15-18
Publication date: 30 Jun 2017

Host publication information

Title of host publication: Proceedings - 2017 IEEE/ACM 39th International Conference on Software Engineering: New Ideas and Emerging Results Track, ICSE-NIER 2017
Publisher: IEEE
ISBN (Electronic): 9781538626757
ASJC Scopus subject areas: Organizational Behavior and Human Resource Management, Software, Management of Technology and Innovation
Keywords: agile development, DevOps, medical software development standards, Regulated software

Bibliographical note

EXT="Kuusinen, Kati"

Source: Scopus
Source ID: 85026751442

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Generalized model of biological neural networks: Progressive operational perceptrons

Traditional Artificial Neural Networks (ANNs) such as Multi-Layer Perceptrons (MLPs) and Radial Basis Functions (RBFs) were designed to simulate biological neural networks; however, they are based only loosely on biology and only provide a crude model. This in turn yields well-known limitations and drawbacks on the performance and robustness. In this paper we shall address them by introducing a novel feed-forward ANN model, Generalized Operational Perceptrons (GOPs) that consist of neurons with distinct (non-)linear operators to achieve a generalized model of the biological neurons and ultimately a superior diversity. We modified the conventional back-propagation (BP) to train GOPs and furthermore, proposed Progressive Operational Perceptrons (POPs) to achieve self-organized and depth-adaptive GOPs according to the learning problem. The most crucial property of the POPs is their ability to simultaneously search for the optimal operator set and train each layer individually. The final POP is, therefore, formed layer by layer and this ability enables POPs with minimal network depth to attack the most challenging learning problems that cannot be learned by conventional ANNs even with a deeper and significantly complex configuration.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG, Qatar University, Izmir University of Economics
Contributors: Kiranyaz, S., Ince, T., Iosifidis, A., Gabbouj, M.
Number of pages: 9
Pages: 2477-2485
Publication date: 30 Jun 2017

Host publication information

Title of host publication: 2017 International Joint Conference on Neural Networks, IJCNN 2017
Publisher: IEEE
ISBN (Electronic): 9781509061815
ASJC Scopus subject areas: Software, Artificial Intelligence

Bibliographical note

jufoid=58177
EXT="Kiranyaz, Serkan"
EXT="Ince, Turker"

Source: Scopus
Source ID: 85031016878

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Running software research programs: An agile approach

Agile, lean processes have become the de-facto way to operate in the domain of software intensive products. Methodologies such as the lean startup are reshaping the way new companies and even well-established enterprises seek new opportunities in their operations. In contrast, in research, little has changed during that time - organizations that fund research still expect a solid, linear research plan. In this paper, we present an attempt to challenge this model in software research, based on 7 years of experiences in two large, national, industry-led projects that followed a more agile mindset. Furthermore, we also provide an insight to key learnings and best practices of running software research in agile fashion.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, F-Secure, VTT Technical Research Centre of Finland
Contributors: Järvinen, J., Huomo, T., Mikkonen, T.
Number of pages: 3
Pages: 314-316
Publication date: 30 Jun 2017

Host publication information

Title of host publication: Proceedings - 2017 IEEE/ACM 39th International Conference on Software Engineering Companion, ICSE-C 2017
Publisher: IEEE
ISBN (Electronic): 9781538615898
ASJC Scopus subject areas: Software, Safety, Risk, Reliability and Quality
Keywords: Agile, Experimentation, Lean, Software research
Source: Scopus
Source ID: 85026771688

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Using and collecting fine-grained usage data to improve online learning materials

As educators seek to create better learning materials, knowledge about how students actually use the materials is priceless. The advent of online learning materials has allowed tracking of student movement on levels not previously possible with on-paper materials: Server logs can be parsed for details on when students opened certain pages. But such data is extremely coarse and only allows for rudimentary usage analysis. How do students move within the course pages? What do they read in detail and what do they glance over? Traditionally, answering such questions has required complex setups with eye tracking labs. In this paper we investigate how fine-grained data about student movement within an online learning material can be used to improve said material in an informed fashion. Our data is collected by a JavaScript-component that tracks which elements of the online learning material are visible on the student's browser window as they study. The data is collected in situ, and no software needs to be installed on the student's computer. We further investigate how such data can be combined with data from a separate learning environment in which students work on course assignments and if the types of movements made by the students are correlated with student self-regulation metrics or course outcomes. Our results indicate that the use of rather simple and non-invasive tracking of students' movements in course materials allows material creators to quickly see major problem-areas in their materials and to highlight sections that students keep returning to. In addition, when the tracking data is combined with student course assignment data, inferring meaningful assignment-specific areas within the course material becomes possible. Finally, we determine that high-level statistics of user movements are not correlated with course outcomes or certain self-regulation related metrics.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Software engineering, University of Helsinki
Contributors: Leppänen, L., Leinonen, J., Ihantola, P., Hellas, A.
Number of pages: 9
Pages: 4-12
Publication date: 29 Jun 2017

Host publication information

Title of host publication: Proceedings - 2017 IEEE/ACM 39th International Conference on Software Engineering: Software Engineering and Education Track, ICSE-SEET 2017
Publisher: IEEE
ISBN (Electronic): 9781538626719
ASJC Scopus subject areas: Computer Science Applications, Software, Education
Keywords: course material usage, e-learning, heat map, learning material evaluation, student behavior, visualization
Source: Scopus
Source ID: 85026769227

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Children designing videos: Tools, pedagogical models, and best practices for digital storytelling and media-making in the classroom

Although video sharing is common among youth, schools are only beginning to apply digital videos and digital storytelling to formal learning. This paper presents pedagogical models, examples, best practices, and outcomes that illustrate how teachers and students design and use digital stories in knowledge creation in cross-cultural settings. The results are based on the empirical data and findings from several international pilot studies. On the one hand, working with digital video stories drove engagement. However, on the other hand, technical issues significantly lowered engagement. In addition, the video inquiry pedagogy supported inquiry learning. Students began to pose scientifically oriented questions and seek answers together.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research group: TUT Game Lab, Pervasive Computing, University of Helsinki, Pepperdine University
Contributors: Multisilta, J., Niemi, H., Hamilton, E.
Number of pages: 4
Pages: 693-696
Publication date: 27 Jun 2017

Host publication information

Title of host publication: IDC 2017 - Proceedings of the 2017 ACM Conference on Interaction Design and Children
Publisher: ACM
ISBN (Electronic): 9781450349215
ASJC Scopus subject areas: Software, Education, Human-Computer Interaction, Developmental and Educational Psychology
Keywords: Children, Media-making, Pedagogical models, STEM, Storytelling, Video
Source: Scopus
Source ID: 85026309191

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Barriers for bridging interpersonal gaps: Three inspirational design patterns for increasing collocated social interaction

Positive face-to-face social encounters between strangers can strengthen the sense of community in modern urban environments. However, it is not always easy to initiate friendly encounters due to various inhibiting social norms. We present three inspirational design patterns for reducing inhibitions to interact with unfamiliar others. These abstractions are based on a broad design space review of concepts, encompassing examples across a range of scales, fields, media and forms. Each inspirational pattern is formulated as a response to a different challenge to initiating social interaction but all share an underlying similarity in offering varieties of barriers and filters that paradoxically also separate people. The patterns are "Closer Through Not Seeing"; "Closer Through Not Touching"; and "Minimize Encounter Duration". We believe these patterns can support designers, in understanding, articulating, and generating approaches to creating embodied interventions and systems that enable unacquainted people to interact.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: User experience, University of Southern Denmark
Contributors: Mitchell, R., Olsson, T.
Number of pages: 9
Pages: 2-10
Publication date: 26 Jun 2017

Host publication information

Title of host publication: C&T 2017 - 8th International Conference on Communities and Technologies, Conference Proceedings
Publisher: ACM
ISBN (Electronic): 9781450348546
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Collocated interaction, Face-to-face interaction, Social interaction design, pattern languages, embodied interaction
Source: Scopus
Source ID: 85025125983

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

A k-nearest neighbor multilabel ranking algorithm with application to content-based image retrieval

Multilabel ranking is an important machine learning task with many applications, such as content-based image retrieval (CBIR). However, when the number of labels is large, traditional algorithms are either infeasible or show poor performance. In this paper, we propose a simple yet effective multilabel ranking algorithm that is based on k-nearest neighbor paradigm. The proposed algorithm ranks labels according to the probabilities of the label association using the neighboring samples around a query sample. Different from traditional approaches, we take only positive samples into consideration and determine the model parameters by directly optimizing ranking loss measures. We evaluated the proposed algorithm using four popular multilabel datasets. The proposed algorithm achieves equivalent or better performance than other instance-based learning algorithms. When applied to a CBIR system with a dataset of 1 million samples and over 190 thousand labels, which is much larger than any other multilabel datasets used earlier, the proposed algorithm clearly outperforms the competing algorithms.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG, Qatar University
Contributors: Zhang, H., Kiranyaz, S., Gabbouj, M.
Number of pages: 5
Pages: 2587-2591
Publication date: 16 Jun 2017

Host publication information

Title of host publication: 2017 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781509041176
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Content-Based Image Retrieval, k-Nearest Neighbor, Multilabel Learning
Source: Scopus
Source ID: 85023746875

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

An accumulative fusion architecture for discriminating people and vehicles using acoustic and seismic signals

In this paper, we develop new multiclass classification algorithms for detecting people and vehicles by fusing data from a multimodal, unattended ground sensor node. The specific types of sensors that we apply in this work are acoustic and seismic sensors. We investigate two alternative approaches to multiclass classification in this context - the first is based on applying Dempster-Shafer Theory to perform score-level fusion, and the second involves the accumulation of local similarity evidences derived from a feature-level fusion model that combines both modalities. We experiment with the proposed algorithms using different datasets obtained from acoustic and seismic sensors in various outdoor environments, and evaluate the performance of the two algorithms in terms of receiver operating characteristic and classification accuracy. Our results demonstrate overall superiority of the proposed new feature-level fusion approach for multiclass discrimination among people, vehicles and noise.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, U.S. Army Research Laboratory, Department of Electrical and Computer Engineering, University of Maryland
Contributors: Lee, K., Riggan, B. S., Bhattacharyya, S. S.
Number of pages: 5
Pages: 2976-2980
Publication date: 16 Jun 2017

Host publication information

Title of host publication: 2017 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781509041176
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: multiclass classification, Sensor fusion, target detection, tracking
Source: Scopus
Source ID: 85023750747

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Inband full-duplex radio access system with self-backhauling: Transmit power minimization under QOS requirements

In this paper, a self-backhauling radio access system is studied and analyzed. In particular, we consider a scenario where a full-duplex access node is serving mobile users simultaneously in uplink and downlink, while also maintaining a wireless backhaul connection. The full-duplex capability of the access node, together with large antenna arrays, allows it to do all of this using the same center frequency. The minimum transmit powers for such a system are solved in a closed form under the condition that certain Quality of Service (QoS) requirements, defined in terms of minimum uplink and downlink data rates, are fulfilled. It is demonstrated with numerical results that, by using the derived expressions for the optimal transmit powers, the probability of fulfilling the QoS requirements is greatly increased, while simultaneously the overall transmit power usage of the system is significantly reduced when compared to a benchmark scheme.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Aalto University
Contributors: Korpi, D., Riihonen, T., Valkama, M.
Number of pages: 5
Pages: 6558-6562
Publication date: 16 Jun 2017

Host publication information

Title of host publication: 2017 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781509041176
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Full-duplex, massive MIMO, self-backhauling
Source: Scopus
Source ID: 85023776611

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Reduced-complexity digital predistortion for massive MIMO

A novel reduced-complexity digital predistortion (DPD) solution is presented in this paper. The proposed DPD can suppress the unwanted distortions due to power amplifier (PA) nonlinearity and I/Q modulator impairments in direct conversion transmitters using reduced-bandwidth filtered basis functions. Moreover, the DPD parameter estimation is based on very simple decorrelation based closed-loop processing and reduced-bandwidth observation, thus further reducing the overall complexity. The proposed DPD can be used in large array or massive MIMO systems with large number of radio transceivers and PAs, where reducing the complexity of the DPD processing is very critical.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Electronics and Communications Engineering, Research group: Wireless Communications and Positioning
Contributors: Abdelaziz, M., Anttila, L., Valkama, M.
Number of pages: 5
Pages: 6478-6482
Publication date: 16 Jun 2017

Host publication information

Title of host publication: 2017 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2017 - Proceedings
Publisher: IEEE
ISBN (Electronic): 9781509041176
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: 5G, Digital Predistortion, Direct Conversion Transmitters, I/Q imbalance, Massive MIMO, Power Amplifiers
Source: Scopus
Source ID: 85023738523

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Comparing communication effort within the scrum, scrum with Kanban, XP, and Banana development processes

[Context]: Communication plays an important role in any development process. However, communication overhead has been rarely compared among development processes. [Objective]: The goal of this work is to compare the communication overhead and the different channels applied in three agile processes (XP, Scrum, Scrum with Kanban) and in an unstructured process. [Method]: We designed an empirical study asking four teams to develop the same application with the four development processes, and we compare the communication overhead among them. [Results]: As expected, face-to-face communication is most frequently employed in the teams. Scrum with Kanban turned out to be the process that requires the least communication. Unexpectedly, despite requiring much more time to develop the same application, the unstructured process required comparable communication overhead (25% of the total development time) as the agile processes.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: University of Oulu, Former organisation of the author
Contributors: Taibi, D., Lenarduzzi, V., Ahmad, M. O., Liukkunen, K.
Number of pages: 6
Pages: 258-263
Publication date: 15 Jun 2017

Host publication information

Title of host publication: Proceedings of the 21st International Conference on Evaluation and Assessment in Software Engineering, EASE 2017
Volume: Part F128635
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450348041
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Agile processes, Case study, Communication, Empirical software engineering
Source: Scopus
Source ID: 85025468824

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Operationalizing the experience factory for effort estimation in agile processes

[Background] The effort required to systematically collect historical data is not always allocable in agile processes and historical data management is usually delegated to the developers' experience, who need to remember previous project details. However, even if well trained, developers cannot precisely remember a huge number of details, resulting in wrong decisions being made during the development process. [Aims] The goal of this paper is to operationalize the Experience Factory in an agile way, i.e., defining a strategy for collecting historical project data using an agile approach. [Method] We provide a mechanism for understanding whether a measure must be collected or not, based on the Return on Invested Time (ROIT). In order to validate this approach, we instantiated the factory with an exploratory case study, comparing four projects that did not use our approach with one project that used it after 12 weeks out of 37 and two projects that used it from the beginning. [Results] The proposed approach helps developers to constantly improve their estimation accuracy with a very positive ROIT of the collected measure. [Conclusions] From this first experience, we can conclude that the Experience Factory can be applied effectively to agile processes, supporting developers in improving their performance and reducing potential decision mistakes.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Fraunhofer IESE, University of Cagliari, Former organisation of the author
Contributors: Taibi, D., Lenarduzzi, V., Diebold, P., Lunesu, I.
Number of pages: 10
Pages: 31-40
Publication date: 15 Jun 2017

Host publication information

Title of host publication: Proceedings of the 21st International Conference on Evaluation and Assessment in Software Engineering, EASE 2017
Volume: Part F128635
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450348041
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Agile software development, Experience factory, Knowledge management
Source: Scopus
Source ID: 85025449243

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Microservices in agile software development: A workshop-based study into issues, advantages, and disadvantages

In the last years, cloud-native architectures have emerged as a target platform for the deployment of microservice architectures. The migration of existing monoliths into cloud-native applications is still in the early phase, and only few companies already started their migrations. Therefore, success and failure stories about different approaches are not available in the literature. This context connects also to the recently discussed DevOps context where development and continuous deployment are closely linked.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Free University of Bolzano-Bozen, Former organisation of the author
Contributors: Taibi, D., Lenarduzzi, V., Pahl, C., Janes, A.
Publication date: 22 May 2017

Host publication information

Title of host publication: Proceedings of the XP2017 Scientific Workshops, XP 2017
Volume: Part F129907
Publisher: Association for Computing Machinery
Article number: a23
ISBN (Electronic): 9781450352642
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Cloud software, Microservices, SOA, Software architecture
Source: Scopus
Source ID: 85029863670

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Comparing the Built-In Application Architecture Models in the Web Browser

Depending on one's viewpoint, a generic standards-compatible web browser supports three, four or five built-in application rendering and programming models. In this paper, we provide an overview of the built-in client-side web application architectures. While the dominance of the base HTML/CSS/JS technologies cannot be ignored, we foresee Web Components and WebGL gaining popularity as the world moves towards more complex and even richer web applications, including systems supporting virtual and augmented reality.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Nokia, University of Helsinki, USI Lugano
Contributors: Taivalsaari, A., Mikkonen, T., Pautasso, C., Systä, K.
Number of pages: 4
Pages: 51-54
Publication date: 16 May 2017

Host publication information

Title of host publication: 2017 IEEE International Conference on Software Architecture (ICSA)
Publisher: IEEE
Article number: 7930198
ISBN (Electronic): 9781509057290
ASJC Scopus subject areas: Software, Computer Networks and Communications, Hardware and Architecture
Keywords: web application architectures, Web development

Bibliographical note

EXT="Taivalsaari, Antero"
EXT="Mikkonen, Tommi"
jufoid=69204

Source: Scopus
Source ID: 85021433872

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Effects of extrinsic noise are promoter kinetics dependent

Studies in Escherichia coli using in vivo single-RNA detection and time-lapse confocal microscopy showed that transcription is a multiple rate-limiting steps process, in agreement with previous in vitro measurements. Here, from simulations of a stochastic model of transcription validated empirically that accounts for cell-to-cell variability in RNA polymerase (RNAP) numbers, we investigate the hypothesis that the cell-to-cell variability in RNA numbers due to RNAP variability differs with the promoter rate-limiting steps dynamics. We find that increasing the cell-to-cell variability in RNAP numbers increases the cell-to-cell diversity in RNA numbers, but the degree with which it increases is promoter kinetics dependent. Namely, promoters whose open complex formation is relatively longer lasting dampen more efficiently this noise propagation phenomenon. We conclude that cell-to-cell variability in RNA numbers due to variability in RNAP numbers is promoter-sequence dependent and, thus, evolvable.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: BioMediTech, Faculty of Biomedical Sciences and Engineering, Research group: Laboratory of Biosystem Dynamics-LBD
Contributors: Bahrudeen, M. N., Startceva, S., Ribeiro, A. S.
Number of pages: 4
Pages: 44-47
Publication date: 14 May 2017

Host publication information

Title of host publication: Proceedings of the 2017 9th International Conference on Bioinformatics and Biomedical Technology, ICBBT 2017
Publisher: ACM
ISBN (Electronic): 9781450348799
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Extrinsic noise, Gene expression, Phenotypic diversity, Rate-limiting steps, Stochastic models, Transcription initiation
Source: Scopus
Source ID: 85025117782

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

Preventing keystroke based identification in open data sets

Large-scale courses such as Massive Online Open Courses (MOOCs) can be a great data source for researchers. Ideally, the data gathered on such courses should be openly available to all researchers. Studies could be easily replicated and novel studies on existing data could be conducted. However, very fine-grained data such as source code snapshots can contain hidden identifiers. For example, distinct typing patterns that identify individuals can be extracted from such data. Hence, simply removing explicit identifiers such as names and student numbers is not sufficient to protect the privacy of the users who have supplied the data. At the same time, removing all keystroke information would decrease the value of the shared data significantly. In this work, we study how keystroke data from a programming context could be modified to prevent keystroke latency based identification whilst still retaining information that can be used to e.g. infer programming experience. We investigate the degree of anonymization required to render identification of students based on their typing patterns unreliable. Then, we study whether the modified keystroke data can still be used to infer the programming experience of the students as a case study of whether the anonymized typing patterns have retained at least some informative value. We show that it is possible to modify data so that keystroke latency based identification is no longer accurate, but the programming experience of the students can still be inferred, i.e. the data still has value to researchers. In a broader context, our results indicate that information and anonymity are not necessarily mutually exclusive.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Software engineering, University of Helsinki
Contributors: Leinonen, J., Ihantola, P., Hellas, A.
Number of pages: 9
Pages: 101-109
Publication date: 12 Apr 2017

Host publication information

Title of host publication: L@S 2017 - Proceedings of the 4th (2017) ACM Conference on Learning at Scale
Publisher: ACM
ISBN (Electronic): 9781450344500
ASJC Scopus subject areas: Computer Networks and Communications, Education, Software, Computer Science Applications
Keywords: Data anonymization, Data privacy, Keystroke dynamics, Programming experience inference, Source code snapshots
Source: Scopus
Source ID: 85018432742

Research output: Chapter in Book/Report/Conference proceedingConference contributionScientificpeer-review

On continuous deployment maturity in customer projects

The practice of making new software available to end users as soon as it gets implemented is becoming commonplace. This paper investigates a set of projects and their development practices in a mid-sized Finnish software company Solita Ltd. to understand how continuous deployment practices are applied in development teams. This was done by establishing a maturity scale and using it to survey the teams. In addition, we interviewed members of selected teams to understand why a particular level of maturity is desirable for a project, and to reveal the issues that impact team's ability to improve. We found that while the team, the customer, and the product all benefit from mature development practices associated with continuous deployment, some obstacles can be solved only by changing the organizational modus operandi.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication