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

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

Adaptive spatial resolution selection for stereoscopic video compression with MV-HEVC: A frequency based approach

One approach for stereoscopic video compression is to down sample the content prior to encoding and up sample it to the original spatial resolution after decoding. In this study it is shown that the ratio by which the content should be rescaled is sequence dependent. Hence, a frequency based method is introduced enabling fast and accurate estimation of the best down sampling ratio for different stereoscopic video clips. It is shown that exploiting this approach can bring 3.38% delta bitrate reduction over five camera-captured sequences.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Video, Research Community on Data-to-Decision (D2D), Nokia
Contributors: Aflaki, P., Hannuksela, M. M., Gabbouj, M.
Number of pages: 4
Pages: 267-270
Publication date: 5 Feb 2015

Host publication information

Title of host publication: 2014 IEEE International Symposium on Multimedia, ISM 2014, 10-12 Dec. 2014, Taichung
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
ISBN (Print): 9781479943111
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Vision and Pattern Recognition, Human-Computer Interaction, Software, Media Technology
Keywords: frequency power spectrum, MVC, objective quality metrics, resolution adjustment

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

Methodology to obtain the security controls in multi-cloud applications

What controls should be used to ensure adequate security level during operation is a non-trivial subject in complex software systems and applications. The problem becomes even more challenging when the application uses multiple cloud services which security measures are beyond the control of the application provider. In this paper, a methodology that enables the identification of the best security controls for multicloud applications whose components are deployed in heterogeneous clouds is presented. The methodology is based on application decomposition and modelling of threats over the components, followed by the analysis of the risks together with the capture of cloud business and security requirements. The methodology has been applied in the MUSA EU H2020 project use cases as the first step for building up the multi-cloud applications' security-aware Service Level Agreements (SLA). The identified security controls will be included in the applications' SLAs for their monitoring and fulfilment assurance at operation.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Automation Science and Engineering, Research group: Factory automation systems technology, Faculty of Engineering Sciences, Factory Automation Systems and Technologies Lab (FAST-Lab), Second University of Naples, ENEA/CREATE/Università Degli Studi Napoli Federico II, TECNALIA. ICT-European Software Institute. Parque Tecnológico de Bizkaia
Contributors: Afolaranmi, S. O., Gonzalez Moctezuma, L. E., Rak, M., Casola, V., Rios, E., Martinez Lastra, J. L.
Number of pages: 6
Pages: 327-332
Publication date: 2016

Host publication information

Title of host publication: CLOSER 2016 - Proceedings of the 6th International Conference on Cloud Computing and Services Science
Volume: 1
Publisher: SCITEPRESS
ISBN (Electronic): 9789897581823
ASJC Scopus subject areas: Computer Science (miscellaneous), Computer Science Applications, Software
Keywords: Cyber-security Methodologies, Multi-cloud, Security-by-design, Threat Modelling
Source: Scopus
Source ID: 84979747685

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

An evaluation framework for cross-platform mobile app development tools: A case analysis of adobe PhoneGap framework

The 'App economy' is a highly lucrative and competitive market for independent software vendors as it potentially offers an easy highway to reach millions of users. However, the mobile application landscape is scattered and an application developer has to publish the software for several different platforms to be able to serve a majority of smartphone users. Therefore, a bunch of cross-development tools have been offered to simplify this workload. In this paper, we present an evaluation framework for comparing different cross-development tools. We use this framework to evaluate Adobe PhoneGap tool against native development in Android and Windows Phone platforms. The results of a case study reveal that while the cross-platform technique was easy to use, the appearance and usability of the app was mediocre at its best. The business impacts of these are also discussed.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Turun Yliopisto/Turun Biomateriaalikeskus
Contributors: Ahti, V., Hyrynsalmi, S., Nevalainen, O.
Number of pages: 8
Pages: 41-48
Publication date: 23 Jun 2016

Host publication information

Title of host publication: Computer Systems and Technologies 17th International Conference, CompSysTech 2016 - Proceedings
Volume: 1164
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450341820
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Cross-platform development, Hybrid mobile app, Mobile application, Multi-platform
Source: Scopus
Source ID: 85001085934

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

Glance awareness and gaze interaction in smartwatches

Smartwatches are widely available and increasingly adopted by consumers. The most common way of interacting with smartwatches is either touching a screen or pressing buttons on the sides. However, such techniques require using both hands. We propose glance awareness and active gaze interaction as alternative techniques to interact with smartwatches. We will describe an experiment conducted to understand the user preferences for visual and haptic feedback on a "glance" at the wristwatch. Following the glance, the users interacted with the watch using gaze gestures. Our results showed that user preferences differed depending on the complexity of the interaction. No clear preference emerged for complex interaction. For simple interaction, haptics was the preferred glance feedback modality. Copyright is held by the author/owner(s).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), Tampere Unit for Computer-Human Interaction (TAUCHI)
Contributors: Akkil, D., Kangas, J., Rantala, J., Isokoski, P., Špakov, O., Raisamo, R.
Number of pages: 6
Pages: 1271-1276
Publication date: 18 Apr 2015

Host publication information

Title of host publication: CHI 2015 - Extended Abstracts Publication of the 33rd Annual CHI Conference on Human Factors in Computing Systems: Crossings
Volume: 18
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450331463
ASJC Scopus subject areas: Human-Computer Interaction, Computer Graphics and Computer-Aided Design, Software
Keywords: Gaze input, Haptic feedback, Wearable computing
Source: Scopus
Source ID: 84954204642

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

SoftWater: Software-defined networking for next-generation underwater communication systems

Underwater communication systems have drawn the attention of the research community in the last 15 years. This growing interest can largely be attributed to new civil and military applications enabled by large-scale networks of underwater devices (e.g., underwater static sensors, unmanned autonomous vehicles (AUVs), and autonomous robots), which can retrieve information from the aquatic and marine environment, perform in-network processing on the extracted data, and transmit the collected information to remote locations. Currently underwater communication systems are inherently hardware-based and rely on closed and inflexible architectural design. This imposes significant challenges into adopting new underwater communication and networking technologies, prevent the provision of truly-differentiated services to highly diverse underwater applications, and induce great barriers to integrate heterogeneous underwater devices. Software-defined networking (SDN), recognized as the next-generation networking paradigm, relies on the highly flexible, programmable, and virtualizable network architecture to dramatically improve network resource utilization, simplify network management, reduce operating cost, and promote innovation and evolution. In this paper, a software-defined architecture, namely SoftWater, is first introduced to facilitate the development of the next-generation underwater communication systems. More specifically, by exploiting the network function virtualization (NFV) and network virtualization concepts, SoftWater architecture can easily incorporate new underwater communication solutions, accordingly maximize the network capacity, can achieve the network robustness and energy efficiency, as well as can provide truly differentiated and scalable networking services. Consequently, the SoftWater architecture can simultaneously support a variety of different underwater applications, and can enable the interoperability of underwater devices from different manufacturers that operate on different underwater communication technologies based on acoustic, optical, or radio waves. Moreover, the essential network management tools of SoftWater are discussed, including reconfigurable multi-controller placement, hybrid in-band and out-of-band control traffic balancing, and utility-optimal network virtualization. Furthermore, the major benefits of SoftWater architecture are demonstrated by introducing software-defined underwater networking solutions, including the throughput-optimal underwater routing, SDN-enhanced fault recovery, and software-defined underwater mobility management. The research challenges to realize the SoftWater are also discussed in detail.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Wireless Communications and Positioning (WICO), Georgia Institute of Technology, School of Electrical and Computer Engineering, Wichita State University
Contributors: Akyildiz, I. F., Wang, P., Lin, S. C.
Publication date: Aug 2016
Peer-reviewed: Yes

Publication information

Journal: Ad Hoc Networks
Volume: 46
ISSN (Print): 1570-8705
Ratings: 
  • Scopus rating (2016): CiteScore 6.1 SJR 0.648 SNIP 2.045
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications
Keywords: SDN, Underwater communications, Virtualization
Source: Scopus
Source ID: 84992306085

Research output: Contribution to journalArticleScientificpeer-review

Novel approaches to crawling important pages early

Web crawlers are essential to many Web applications, such as Web search engines, Web archives, and Web directories, which maintain Web pages in their local repositories. In this paper, we study the problem of crawl scheduling that biases crawl ordering toward important pages. We propose a set of crawling algorithms for effective and efficient crawl ordering by prioritizing important pages with the well-known PageRank as the importance metric. In order to score URLs, the proposed algorithms utilize various features, including partial link structure, inter-host links, page titles, and topic relevance. We conduct a large-scale experiment using publicly available data sets to examine the effect of each feature on crawl ordering and evaluate the performance of many algorithms. The experimental results verify the efficacy of our schemes. In particular, compared with the representative RankMass crawler, the FPR-title-host algorithm reduces computational overhead by a factor as great as three in running time while improving effectiveness by 5% in cumulative PageRank.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Korea University
Contributors: Alam, M. H., Ha, J. W., Lee, S. K.
Number of pages: 28
Pages: 707-734
Publication date: 2012
Peer-reviewed: Yes

Publication information

Journal: Knowledge and Information Systems
Volume: 33
Issue number: 3
ISSN (Print): 0219-1377
Ratings: 
  • Scopus rating (2012): CiteScore 4.2 SJR 1.111 SNIP 2.008
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Human-Computer Interaction, Hardware and Architecture, Artificial Intelligence
Keywords: Crawl ordering, Fractional PageRank, PageRank, Web crawler
Source: Scopus
Source ID: 84869092092

Research output: Contribution to journalArticleScientificpeer-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

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

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

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

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

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

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

Intentstreams: Smart parallel search streams for branching exploratory search

The user's understanding of information needs and the information available in the data collection can evolve during an exploratory search session. Search systems tailored for well-defined narrow search tasks may be suboptimal for exploratory search where the user can sequentially refine the expressions of her information needs and explore alternative search directions. A major challenge for exploratory search systems design is how to support such behavior and expose the user to relevant yet novel information that can be difficult to discover by using conventional query formulation techniques. We introduce IntentStreams, a system for exploratory search that provides interactive query refinement mechanisms and parallel visualization of search streams. The system models each search stream via an intent model allowing rapid user feedback. The user interface allows swift initiation of alternative and parallel search streams by direct manipulation that does not require typing. A study with 13 participants shows that IntentStreams provides better support for branching behavior compared to a conventional search system.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research Community on Data-to-Decision (D2D), University of Helsinki, Aalto University, School of Management (JKK)
Contributors: Andolina, S., Klouche, K., Peltonen, J., Hoque, M., Ruotsalo, T., Cabral, D., Klami, A., Głowacka, D., Floréen, P., Jacucci, G.
Number of pages: 6
Pages: 300-305
Publication date: 18 Mar 2015

Host publication information

Title of host publication: IUI 2015 - Proceedings of the 20th ACM International Conference on Intelligent User Interfaces
Volume: 2015-January
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450333061
ASJC Scopus subject areas: Software, Human-Computer Interaction
Keywords: Information exploration, Parallel browsing, User interface design
Source: Scopus
Source ID: 84939638219

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

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

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

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

Railway fastener inspection by real-time machine vision

In this paper, a real-time railway fastener detection system using a high-speed laser range finder camera is presented. First, an extensive analysis of various methods based on pixel-wise and histogram similarities are conducted on a specific railway route. Then, a fusing stage is introduced which combines least correlated approaches also considering the performance upgrade after fusing. Then, the resulting method is tested on a larger database collected from a different railway route. After observing repeated successes, the method is implemented on NI LabVIEW and run real-time with a high-speed 3-D camera placed under a railway carriage designed for railway quality inspection.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Video, Middle East Technical University, Electrical and Electronics Engineering Department
Contributors: Aytekin, C., Rezaeitabar, Y., Dogru, S., Ulusoy, I.
Number of pages: 7
Pages: 1101-1107
Publication date: 1 Jul 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Systems, Man, and Cybernetics: Systems
Volume: 45
Issue number: 7
ISSN (Print): 1083-4427
Ratings: 
  • Scopus rating (2015): CiteScore 6.1 SJR 1.273 SNIP 2.189
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Human-Computer Interaction, Software, Control and Systems Engineering, Electrical and Electronic Engineering
Keywords: High-speed laser range finder, railway fastener detection, railway inspection
Source: Scopus
Source ID: 84932638036

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

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

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

Collaborative filtering based on group coordinates for smoothing and directional sharpening

Groups of mutually similar image blocks are the key element in nonlocal image processing. In this work, the spatial coordinates of grouped blocks are leveraged in two distinct parts of the transform-domain collaborative filtering within the BM3D algorithm. First, we introduce an adaptive 1-D transform for 3-D collaborative filtering based on sampling 2-D smooth functions at the positions of grouped blocks. This adaptive transform is applied for improved decorrelation of the 2-D spectra of the grouped blocks. Second, we propose a directional sharpening procedure whose strength varies adaptively according to the relative orientation of the transform basis functions with respect to the group coordinates. Experiments confirm the efficacy of the proposed adaptations, for denoising as well as for sharpening of noisy images.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Signal and Image Restoration-RST, Research area: Signal and Information Processing, Signal Processing Research Community (SPRC)
Contributors: Azzari, L., Foi, A.
Number of pages: 5
Pages: 1573-1577
Publication date: 4 Aug 2015

Host publication information

Title of host publication: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publisher: IEEE
ISBN (Print): 9781467369978
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: adaptive transforms, BM3D, collaborative filtering, denoising, sharpening
Source: Scopus
Source ID: 84946074037

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

Urban 3D segmentation and modelling from street view images and LiDAR point clouds

3D urban maps with semantic labels and metric information are not only essential for the next generation robots such autonomous vehicles and city drones, but also help to visualize and augment local environment in mobile user applications. The machine vision challenge is to generate accurate urban maps from existing data with minimal manual annotation. In this work, we propose a novel methodology that takes GPS registered LiDAR (Light Detection And Ranging) point clouds and street view images as inputs and creates semantic labels for the 3D points clouds using a hybrid of rule-based parsing and learning-based labelling that combine point cloud and photometric features. The rule-based parsing boosts segmentation of simple and large structures such as street surfaces and building facades that span almost 75% of the point cloud data. For more complex structures, such as cars, trees and pedestrians, we adopt boosted decision trees that exploit both structure (LiDAR) and photometric (street view) features. We provide qualitative examples of our methodology in 3D visualization where we construct parametric graphical models from labelled data and in 2D image segmentation where 3D labels are back projected to the street view images. In quantitative evaluation we report classification accuracy and computing times and compare results to competing methods with three popular databases: NAVTEQ True, Paris-Rue-Madame and TLS (terrestrial laser scanned) Velodyne.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Vision, Nokia
Contributors: Babahajiani, P., Fan, L., Kämäräinen, J., Gabbouj, M.
Number of pages: 16
Pages: 679–694
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: Machine Vision and Applications
Volume: 28
Issue number: 7
ISSN (Print): 0932-8092
Ratings: 
  • Scopus rating (2017): CiteScore 5.3 SJR 0.485 SNIP 1.683
Original language: English
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Vision and Pattern Recognition, Computer Science Applications
Keywords: LiDAR, Point cloud, Robotics, Semantic segmentation, Street view, Urban 3D

Bibliographical note

EXT="Babahajiani, Pouria"

Source: Scopus
Source ID: 85019692066

Research output: Contribution to journalArticleScientificpeer-review

Exemplar-based speech enhancement for deep neural network based automatic speech recognition

Deep neural network (DNN) based acoustic modelling has been successfully used for a variety of automatic speech recognition (ASR) tasks, thanks to its ability to learn higher-level information using multiple hidden layers. This paper investigates the recently proposed exemplar-based speech enhancement technique using coupled dictionaries as a pre-processing stage for DNN-based systems. In this setting, the noisy speech is decomposed as a weighted sum of atoms in an input dictionary containing exemplars sampled from a domain of choice, and the resulting weights are applied to a coupled output dictionary containing exemplars sampled in the short-time Fourier transform (STFT) domain to directly obtain the speech and noise estimates for speech enhancement. In this work, settings using input dictionary of exemplars sampled from the STFT, Mel-integrated magnitude STFT and modulation envelope spectra are evaluated. Experiments performed on the AURORA-4 database revealed that these pre-processing stages can improve the performance of the DNN-HMM-based ASR systems with both clean and multi-condition training.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Audio research group, Signal Processing Research Community (SPRC), KU Leuven
Contributors: Baby, D., Gemmeke, J. F., Virtanen, T., Van Hamme, H.
Number of pages: 5
Pages: 4485-4489
Publication date: 4 Aug 2015

Host publication information

Title of host publication: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
ISBN (Print): 9781467369978
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: coupled dictionaries, deep neural networks, modulation envelope, non-negative matrix factorisation, speech enhancement
Source: Scopus
Source ID: 84946079930

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

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

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

Low-Latency Sound-Source-Separation using Non-Negative Matrix Factorisation with Coupled Analysis and Synthesis Dictionaries

For real-time or close to real-time applications, sound source separation can be performed on-line, where new frames of incoming data for a mixture signal are processed as they arrive, at very low delay. We propose an approach which generates the separation filters for short synthesis frames to achieve low latency source separation, based on a compositional model mixture of the audio to be separated. Filter parameters are derived from a longer temporal context than the current processing frame through use of a longer analysis frame. A pair of dictionaries are used, one for analysis and one for reconstruction. With this approach we are able to increase separation performance at low latencies whilst retaining the low-latency provided by the use of short synthesis frames. The proposed data handling scheme and parameters can be adjusted to achieve real-time performance, given sufficient computational power. Low-latency output allows a human listener to use the results of such a separation scheme directly, without a perceptible delay. With the proposed method, separated source-to-distortion ratios (SDRs) can be improved by over 1 dB for latencies below 20 ms, without any affect on latency.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Audio research group, Signal Processing Research Community (SPRC)
Contributors: Barker, T., Virtanen, T., Pontoppidan, N. H.
Number of pages: 5
Pages: 241-245
Publication date: 4 Aug 2015

Host publication information

Title of host publication: 2015 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
Publisher: IEEE
ISBN (Print): 9781467369978
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: low-latency, NMF, Non-negative matrix factorisation, real-time, source separation
Source: Scopus
Source ID: 84946043719

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

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

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

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

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

Data-driven stream mining systems for computer vision

In this chapter, we discuss the state of the art and future challenges in adaptive stream mining systems for computer vision. Adaptive stream mining in this context involves the extraction of knowledge from image and video streams in real-time, and from sources that are possibly distributed and heterogeneous. With advances in sensor and digital processing technologies, we are able to deploy networks involving large numbers of cameras that acquire increasing volumes of image data for diverse applications in monitoring and surveillance. However, to exploit the potential of such extensive networks for image acquisition, important challenges must be addressed in efficient communication and analysis of such data under constraints on power consumption, communication bandwidth, and end-to-end latency. We discuss these challenges in this chapter, and we also discuss important directions for research in addressing such challenges using dynamic, data-driven methodologies.

General information

Publication status: Published
MoE publication type: A3 Part of a book or another research book
Organisations: Signal Processing Research Community (SPRC), University of Maryland, Electrical Engineering Department, University of California, Los Angeles (UCLA)
Contributors: Bhattacharyya, S. S., Van Der Schaar, M., Atan, O., Tekin, C., Sudusinghe, K.
Number of pages: 16
Pages: 249-264
Publication date: 2014

Host publication information

Title of host publication: Advances in Computer Vision and Pattern Recognition
Volume: 68
Publisher: SPRINGER-VERLAG LONDON LTD

Publication series

Name: Advances in Computer Vision and Pattern Recognition
Volume: 68
ISSN (Print): 21916586
ISSN (Electronic): 21916594
ASJC Scopus subject areas: Software, Signal Processing, Computer Vision and Pattern Recognition, Artificial Intelligence
Source: Scopus
Source ID: 84984919867

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

Method for Simulating Dose Reduction in Digital Breast Tomosynthesis

This work proposes a new method of simulating dose reduction in digital breast tomosynthesis (DBT), starting from a clinical image acquired with a standard radiation dose. It considers both signal-dependent quantum and signal-independent electronic noise. Furthermore, the method accounts for pixel crosstalk, which causes the noise to be frequency-dependent, thus increasing the simulation accuracy. For an objective assessment, simulated and real images were compared in terms of noise standard deviation, signal-to-noise ratio (SNR) and normalized noise power spectrum (NNPS). A two-alternative forced-choice (2-AFC) study investigated the similarity between the noise strength of low-dose simulated and real images. Six experienced medical physics specialists participated on the study, with a total of 2,160 readings. Objective assessment showed no relevant trends with the simulated noise. The relative error in the standard deviation of the simulated noise was less than 2% for every projection angle. The relative error of the SNR was less than 1.5%, and the NNPS of the simulated images had errors less than 2.5%. The 2-AFC human observer experiment yielded no statistically significant difference (p=0.84) in the perceived noise strength between simulated and real images. Furthermore, the observer study also allowed the estimation of a dose difference at which the observer perceived a just-noticeable difference (JND) in noise levels. The estimated JND value indicated that a change of 17% in the current-time product was sufficient to cause a noticeable difference in noise levels. The observed high accuracy, along with the flexible calibration, make this method an attractive tool for clinical image-based simulations of dose reduction.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Signal and Image Restoration-RST
Contributors: Borges, L. R., Guerrero, I., Bakic, P. R., Foi, A., Maidment, A. D., Vieira, M. A.
Pages: 2331-2342
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Medical Imaging
Volume: 36
Issue number: 11
ISSN (Print): 0278-0062
Ratings: 
  • Scopus rating (2017): CiteScore 9.3 SJR 1.895 SNIP 2.904
Original language: English
ASJC Scopus subject areas: Software, Radiological and Ultrasound Technology, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Biomedical imaging, Breast, Calibration, digital breast tomosynthesis, dose reduction, Electronic noise, Estimation, Image reconstruction, quantum noise, Signal to noise ratio, Standards
Electronic versions: 
Source: Scopus
Source ID: 85023177059

Research output: Contribution to journalArticleScientificpeer-review

Scheduling of CAL actor networks based on dynamic code analysis

CAL is a dataflow oriented language for writing high-level specifications of signal processing applications. The language has recently been standardized and selected for the new MPEG Reconfigurable Video Coding standard.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing Research Community (SPRC), University of Oulu, Univ of Oulu, UBL
Contributors: Boutellier, J., Silven, O., Raulet, M.
Number of pages: 4
Pages: 1609-1612
Publication date: 2011

Host publication information

Title of host publication: 2011 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2011 - Proceedings
Article number: 5946805
ISBN (Print): 9781457705397
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: data flow computing, Processor scheduling, video coding
Source: Scopus
Source ID: 80051648157

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

Bit-sliced binary normal basis multiplication

The performance of many cryptographic primitives is reliant on efficient algorithms and implementation techniques for arithmetic in binary fields. While dedicated hardware support for said arithmetic is an emerging trend, the study of software-only implementation techniques remains important for legacy or non-equipped processors. One such technique is that of software-based bit-slicing. In the context of binary fields, this is an interesting option since there is extensive previous work on bit-oriented designs for arithmetic in hardware, such designs are intuitively well suited to bit-slicing in software. In this paper we harness previous work, using it to investigate bit-sliced, software-only implementation arithmetic for binary fields, over a range of practical field sizes and using a normal basis representation. We apply our results to demonstrate significant performance improvements for a stream cipher, and over the frequently employed Ning-Yin approach to normal basis implementation in software.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Intelligent dexterity for secure networked infrastructure and applications (IDSNIA), Department of Information and Computer Science, Aalto University, University of Bristol
Contributors: Brumley, B., Page, D.
Number of pages: 8
Pages: 205-212
Publication date: 2011

Host publication information

Title of host publication: Proceedings - 20th IEEE Symposium on Computer Arithmetic, ARITH-20
Article number: 5992128
ISBN (Print): 9780769543185
ASJC Scopus subject areas: Theoretical Computer Science, Software, Hardware and Architecture
Keywords: Algorithm design, analysis, Computations in finite fields, Computer arithmetic, Data encryption
Source: Scopus
Source ID: 80055027798

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

Conversion algorithms and implementations for koblitz curve cryptography

In this paper, we discuss conversions between integers and \tau-adic expansions and we provide efficient algorithms and hardware architectures for these conversions. The results have significance in elliptic curve cryptography using Koblitz curves, a family of elliptic curves offering faster computation than general elliptic curves. However, in order to enable these faster computations, scalars need to be reduced and represented using a special base-τ expansion. Hence, efficient conversion algorithms and implementations are necessary. Existing conversion algorithms require several complicated operations, such as multiprecision multiplications and computations with large rationals, resulting in slow and large implementations in hardware and microcontrollers with limited instruction sets. Our algorithms are designed to utilize only simple operations, such as additions and shifts, which are easily implementable on practically all platforms. We demonstrate the practicability of the new algorithms by implementing them on Altera Stratix ∥ FPGAs. The implementations considerably improve both computation speed and required area compared to the existing solutions.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Aalto University
Contributors: Brumley, B. B., Jarvinen, K. U.
Number of pages: 12
Pages: 81-92
Publication date: 4 Jan 2010
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Computers
Volume: 59
Issue number: 1
Article number: 5255226
ISSN (Print): 0018-9340
Ratings: 
  • Scopus rating (2010): SJR 0.584 SNIP 1.868
Original language: English
ASJC Scopus subject areas: Software, Theoretical Computer Science, Hardware and Architecture, Computational Theory and Mathematics
Keywords: Elliptic curve cryptography, Field-programmable gate arrays, Koblitz curves, Public-key cryptosystems
Source: Scopus
Source ID: 72949120592

Research output: Contribution to journalArticleScientificpeer-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

2nd international workshop on pervasive eye tracking and mobile eye-based interaction (PETMEI 2012): Proposal for a workshop (mini-track) at UbiComp 2012

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), University of Cambridge, Lessius University College, Zhejiang University of Technology
Contributors: Bulling, A., Brône, G., Cheng, S., Majaranta, P.
Number of pages: 4
Pages: 673-676
Publication date: 2012

Host publication information

Title of host publication: UbiComp'12 - Proceedings of the 2012 ACM Conference on Ubiquitous Computing
ISBN (Print): 9781450312240
ASJC Scopus subject areas: Software
Source: Scopus
Source ID: 84879468823

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

Optimal neighborhood preserving visualization by Maximum satisfiability

We present a novel approach to low-dimensional neighbor embedding for visualization, based on formulating an information retrieval based neighborhood preservation cost function as Maximum satisfiability on a discretized output display. The method has a rigorous interpretation as optimal visualization based on the cost function. Unlike previous lowdimensional neighbor embedding methods, our formulation is guaranteed to yield globally optimal visualizations, and does so reasonably fast. Unlike previous manifold learning methods yielding global optima of their cost functions, our cost function and method are designed for low-dimensional visualization where evaluation and minimization of visualization errors are crucial. Our method performs well in experiments, yielding clean embeddings of datasets where a stateof-the-art comparison method yields poor arrangements. In a real-world case study for semi-supervised WLAN signal mapping in buildings we outperform state-of-the-art methods.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research Community on Data-to-Decision (D2D), Aalto University, University of Helsinki
Contributors: Bunte, K., Järvisalo, M., Berg, J., Myllymäki, P., Peltonen, J., Kaski, S.
Number of pages: 7
Pages: 1694-1700
Publication date: 2014

Host publication information

Title of host publication: Proceedings of the National Conference on Artificial Intelligence
Volume: 3
Publisher: AI Access Foundation
ISBN (Electronic): 9781577356790
ASJC Scopus subject areas: Software, Artificial Intelligence
Source: Scopus
Source ID: 84908213640

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

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

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

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

Configurable, resource-optimized FFT architecture for OFDM communication

In this paper, we present a designer-configurable, resource efficient FPGA architecture for OFDM system implementation. Our design achieves a significant improvement in resource efficiency for a given data rate. This efficiency improvement is achieved through careful analysis of how FFT computation is performed within the context of OFDM systems, and streamlining memory management and control logic based on this analysis. In particular, our OFDM-targeted FFT design eliminates redundant buffer memory, and simplifies control logic to save FPGA resources. We have synthesized and tested our design using the Xilinx ISE 13.4 synthesis tool, and compared the results with the Xilinx FFT v7.1, which is a widely used commercial FPGA IP core. We have demonstrated that our design provides at least 8.8% enhancement in terms of resource efficiency compared to Xilinx FFT v7.1 when it is embedded within the same OFDM configuration.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing Research Community (SPRC), University of Maryland, Agilent Technologies, Department of Electrical and Computer Engineering
Contributors: Cho, I., Shen, C. C., Tachwali, Y., Hsu, C. J., Bhattacharyya, S. S.
Number of pages: 5
Pages: 2746-2750
Publication date: 18 Oct 2013

Host publication information

Title of host publication: 2013 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2013 - Proceedings
Article number: 6638156
ISBN (Print): 9781479903566
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: FFT, FPGA, OFDM, Resource
Source: Scopus
Source ID: 84890522532

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

"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

The usability of text entry systems now and in the future

Text entry is an active and growing research domain. Our SIG serves three purposes. First, to strengthen the text entry community by bringing text entry researchers working in the human-computer interaction, natural language processing and augmentative and alternative communication communities together in one room. Second, to promote CHI as a natural and compelling focal point for all kinds of text entry research. Third, to follow-up on and broaden the discussions that emerged from two previous text entry workshops held at CHI [3, 4] by engaging in dialog to identify obstacles for success and formalizing procedures for measuring progress in the field of text entry.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), Georgia Institute of Technology, University of Glasgow, Max Planck Institute for Informatics, University of Strathclyde, Montana Tech., University of St Andrews, University of Dundee
Contributors: Clawson, J., Isokoski, P., Brewster, S., Oulasvirta, A., Dunlop, M., Vertanen, K., Kristensson, P. O., Waller, A.
Number of pages: 4
Pages: 1139-1142
Publication date: 2014

Host publication information

Title of host publication: CHI EA 2014: One of a ChiNd - Extended Abstracts, 32nd Annual ACM Conference on Human Factors in Computing Systems
Publisher: Association for Computing Machinery
ISBN (Print): 9781450324748
ASJC Scopus subject areas: Human-Computer Interaction, Computer Graphics and Computer-Aided Design, Software
Keywords: Accessibility, Augmentative and alternative communication, Internationalization, Text entry
Source: Scopus
Source ID: 84900546037

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

On the arity gap of finite functions: Results and applications

Let A be a finite set and B an arbitrary set with at least two elements. The arity gap of a function f : An → B is the minimum decrease in the number of essential variables when essential variables of f are identified. A non- Trivial fact is that the arity gap of such B-valued functions on A is at most |A|. Even less trivial to verify is the fact that the arity gap of B-valued functions on A with more than |A| essential variables is at most 2. These facts ask for a classification of B-valued functions on A in terms of their arity gap. In this paper, we survey what is known about this problem. We present a general characterization of the arity gap of B-valued functions on A and provide explicit classifications of the arity gap of Boolean and pseudo-Boolean functions. Moreover, we reveal unsettled questions related to this topic, and discuss links and possible applications of some results to other subjects of research.

General information

Publication status: Published
MoE publication type: A2 Review article in a scientific journal
Organisations: Department of Mathematics, Université de Lorraine, Department of Combinatorics and Optimization, University of Waterloo, Computer Science and Communications Research Unit, University of Luxembourg
Contributors: Couceiro, M., Lehtonen, E.
Number of pages: 15
Pages: 193-207
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Journal of Multiple-Valued Logic and Soft Computing
Volume: 27
Issue number: 2-3
ISSN (Print): 1542-3980
Ratings: 
  • Scopus rating (2016): CiteScore 0.9 SJR 0.26 SNIP 0.571
Original language: English
ASJC Scopus subject areas: Software, Logic, Theoretical Computer Science
Source: Scopus
Source ID: 84979953947

Research output: Contribution to journalReview ArticleScientificpeer-review

Salient event detection in basketball mobile videos

Modern smartphones have become the most popular means for recording videos. In fact, thanks to their portability, smartphones allow for recording anything and at any moment of our everyday life. One common occasion is represented by sport happenings, where people often record their favourite team or players. Automatic analysis of such videos is important for enabling applications such as automatic organization, browsing and summarization of the content. This paper proposes novel algorithms for the detection of salient events in videos recorded at basketball games. The novel approach consists of jointly analyzing visual data and magnetometer data. The magnetometer data provides information about the horizontal orientation of the camera. The proposed joint analysis allows for a reduced number of false positives and for a reduced computational complexity. The algorithms are tested on data captured during real basketball games. The experimental results clearly show the advantages of the proposed approach.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Video, Research Community on Data-to-Decision (D2D), Nokia Technologies
Contributors: Cricri, F., Mate, S., Curcio, I. D. D., Gabbouj, M.
Number of pages: 8
Pages: 63-70
Publication date: 5 Feb 2015

Host publication information

Title of host publication: Proceedings - 2014 IEEE International Symposium on Multimedia, ISM 2014
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
Article number: 7032995
ISBN (Print): 978-1-4799-4312-8
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Computer Vision and Pattern Recognition, Human-Computer Interaction, Software, Media Technology
Keywords: Basketball, detection, event, mobile, video

Bibliographical note

EXT="Curcio, Igor D D"
EXT="Mate, Sujeet"

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

Front-camera video recordings as emotion responses to mobile photos shared within close-knit groups

People use social-photography services to tell stories about themselves and to solicit responses from viewers. State-of-the-art services concentrate on textual comments, "Like" buttons, or similar means for viewers to give explicit feedback, but they overlook other, non-textual means. This paper investigates how emotion responses-as video clips captured by the front camera of a cell phone and used as tags for the individual photo viewed-can enhance photo-sharing experiences for close-knit groups. Our exploration was carried out with a mobile social-photography service called Social Camera. Four user groups (N=19) used the application for two to four weeks. The study's results support the value of using front-camera video recordings to glean emotion response. It supports lightweight phatic social interactions not possible with comments and "Like" buttons. Most users kept sharing emotion responses throughout the study. They typically shared the responses right after they saw a just-taken photo received from a remote partner. They used the responses to share their current contexts with others just as much as to convey nuanced feelings about a photo. We discuss the implications for future design and research.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), Nokia
Contributors: Cui, Y., Kangas, J., Holm, J., Grassel, G.
Number of pages: 10
Pages: 981-990
Publication date: 2013

Host publication information

Title of host publication: CHI 2013: Changing Perspectives, Conference Proceedings - The 31st Annual CHI Conference on Human Factors in Computing Systems
ISBN (Print): 9781450318990
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Graphics and Computer-Aided Design
Keywords: Close-knit group, Co-presence, Emotion response, Feedback, Mobile, Social camera, Social photography
Source: Scopus
Source ID: 84877935649

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

Blind sub-Nyquist GNSS signal detection

A satellite navigation receiver traditionally searches for positioning signals using an acquisition procedure. In situations, in which the required information is only a binary decision whether at least one positioning signal is present or absent, the procedure represents an unnecessarily complex solution. This paper presents a different approach for the binary detection problem with significantly reduced computational complexity. The approach is based on a novel decision metric which is utilized to design two binary detectors. The first detector operates under the theoretical assumption of additive white Gaussian noise and is evaluated by means of Receiver Operating Characteristics. The second one considers also additional interferences and is suitable to operate in a real environment. Its performance is verified using a signal captured by a receiver front-end.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Electronics and Communications Engineering, Department of Mathematics, Research group: MAT Intelligent Information Systems Laboratory, Research group: System-on-Chip for GNSS, Wireless Communications and Cyber-Physical Embedded Computing, Advanced Technology Europe, Nottingham Geospatial Institute, University of Nottingham, Chalmers University of Technology
Contributors: Daniel, O., Raasakka, J., Peltola, P., Fröhle, M., Rivero-Rodriguez, A., Wymeersch, H., Nurmi, J.
Number of pages: 5
Pages: 6575-6579
Publication date: 18 May 2016

Host publication information

Title of host publication: 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
Publisher: IEEE
ISBN (Print): 9781479999880
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: Global Navigation Satellite Systems, indoor/outdoor detection, signal detection

Bibliographical note

EXT="Raasakka, Jussi"
EXT="Peltola, Pekka"

Source: Scopus
Source ID: 84973379949

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

A computational approach to construct a multivariate complete graph invariant

In this paper, we present a computational approach for finding complete graph invariants. Specifically, we generate exhaustive sets of connected, non-isomorphic graphs with 9 and 10 vertices and demonstrate that a 97-dimensional multivariate graph invariant is capable to distinguish each of the non-isomorphic graphs. Furthermore, in order to tame the computational complexity of the problem caused by the vast number of graphs, e.g., involving over 10 million networks with 10 vertices, we suggest a low-dimensional, iterative procedure that is based on highly discriminative individual graph invariants. We show that also this computational approach leads to a perfect discrimination. Overall, our numerical results prove the existence of such graph invariants for networks with 9 and 10 vertices. Furthermore, we show that our iterative approach has a polynomial time complexity.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), 6060 Hall in Tyrol, Computational Biology and Machine Learning, Queen's University, Belfast, Northern Ireland
Contributors: Dehmer, M., Emmert-Streib, F., Grabner, M.
Number of pages: 9
Pages: 200-208
Publication date: 1 Mar 2014
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 260
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2014): CiteScore 7.4 SJR 2.226 SNIP 3.198
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management
Keywords: Information inequality, Quantitative graph theory, Random network model, Statistics
Source: Scopus
Source ID: 84891738883

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

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

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

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

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

The QualiSPo approach to OSS product quality evaluation

The quality of Open Source Software (OSS) is generally much debated. Some state that it is generally higher than closed-source counterparts, while others are more skeptical. In the QualiSPo project the authors addressed the problem of evaluating OSS products in a manner that is both as complete as possible and objective. To this end, a toolset and an evaluation framework are needed. The paper describes such toolset and framework, and accounts for the first evaluations that are being obtained.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: University College Dublin, Ireland, Christina Thorpe, Università degli Studi Dell'Insubria, Universita' degli Studi dell'Insubria
Contributors: Del Bianco, V., Lavazza, L., Morasca, S., Taibi, D., Tosi, D.
Number of pages: 6
Pages: 23-28
Publication date: 2010

Host publication information

Title of host publication: 3rd Int. Workshop on Emerging Trends in Free/Libre/Open Source Software Research and Development, FLOSS-3, in Conj. with the 32nd ACM/IEEE International Conference on Software Engineering, ICSE 2010
ISBN (Print): 9781605589787
ASJC Scopus subject areas: Software
Keywords: open source software, software quality evaluation, software trustworthiness
Source: Scopus
Source ID: 77955875392

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

A survey on open source software trustworthiness

Trustworthiness is a crucial characteristic when it comes to evaluating any product, even more so for open source software, which is now becoming widely used. The authors conducted a survey to identify the reasons and motivations that lead software companies to adopt or reject open source software; they then ranked, according to importance, the specific trust factors used when selecting an open source software component or product. The motivations and importance ranking of factors might be useful for both developers of open source software (to make their products and components more useful for other stakeholders) and to future prospective open source software users.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Università degli Studi Dell'Insubria, Uni-versità Degli Studi dell'Insubria in Como, Universita' degli Studi dell'Insubria
Contributors: Del Bianco, V., Lavazza, L., Morasca, S., Taibi, D.
Number of pages: 9
Pages: 67-75
Publication date: Sep 2011
Peer-reviewed: Yes

Publication information

Journal: IEEE Software
Volume: 28
Issue number: 5
ISSN (Print): 0740-7459
Ratings: 
  • Scopus rating (2011): CiteScore 3.2 SJR 0.701 SNIP 2.255
Original language: English
ASJC Scopus subject areas: Software
Keywords: external software qualities, internal software qualities, open source software, pragmatic software engineering, trustworthiness
Source: Scopus
Source ID: 80051758696

Research output: Contribution to journalArticleScientificpeer-review

Network signatures based on gene pair expression ratios improve classification and the analysis of muscle-invasive urothelial cancer

Urothelial cancer (UC) is highly recurrent and can progress from non-invasive (NMIUC) to a more aggressive muscle-invasive (MIUC) subtype that invades the muscle tissue layer of the bladder. We present a proof of principle study that network-based features of gene pairs can be used to improve classifier performance and the functional analysis of urothelial cancer gene expression data. In the first step of our procedure each individual sample of a UC gene expression dataset is inflated by gene pair expression ratios that are defined based on a given network structure. In the second step an elastic net feature selection procedure for network-based signatures is applied to discriminate between NMIUC and MIUC samples. We performed a repeated random subsampling cross validation in three independent datasets. The network signatures were characterized by a functional enrichment analysis and studied for the enrichment of known cancer genes. We observed that the network-based gene signatures from meta collections of proteinprotein interaction (PPI) databases such as CPDB and the PPI databases HPRD and BioGrid improved the classification performance compared to single gene based signatures. The network based signatures that were derived from PPI databases showed a prominent enrichment of cancer genes (e.g., TP53, TRIM27 and HNRNPA2Bl). We provide a novel integrative approach for large-scale gene expression analysis for the identification and development of novel diagnostical targets in bladder cancer. Further, our method allowed to link cancer gene associations to network-based expression signatures that are not observed in gene-based expression signatures.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research Community on Data-to-Decision (D2D), Harvard Medical School, Queen's University, Belfast, Northern Ireland
Contributors: De Matos Simoes, R., Mitsiades, C., Williamson, K. E., Emmert-Streib, F.
Number of pages: 8
Pages: 1216-1223
Publication date: 16 Dec 2015

Host publication information

Title of host publication: 2015 IEEE International Conference on Bioinformatics and Biomedicine (BIBM)
Publisher: IEEE
ISBN (Electronic): 978-1-4673-6799-8
ASJC Scopus subject areas: Software, Artificial Intelligence, Health Informatics, Biomedical Engineering
Keywords: data feature space inflation, feature selection, gene pair expression ratio, muscle-invasive, non muscleinvasive, Urothelial cancer
Source: Scopus
Source ID: 84962439353

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

Process configuration framework tool

Organizations considering the adoption of new methods, techniques, or tools often face the problem of how to evaluate these systematically, thoroughly, and completely. In this work we present the Process Configuration Framework Tool, a web application based on the Reference Technology platform and aimed at helping organizations find empirical evidence in a specific context. These results will help decision makers to easily find existing methods, techniques, and tools in the appropriate context and make decisions based on empirical evidence.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Fraunhofer IESE, Liebherr-Aerospace, Former organisation of the author
Contributors: Diebold, P., Dieudonne, L., Taibi, D.
Number of pages: 2
Pages: 389-390
Publication date: 17 Oct 2014

Host publication information

Title of host publication: Proceedings - 40th Euromicro Conference Series on Software Engineering and Advanced Applications, SEAA 2014
Publisher: Institute of Electrical and Electronics Engineers Inc.
ISBN (Electronic): 9781479957941
ASJC Scopus subject areas: Software
Keywords: process improvement, process selection
Source: Scopus
Source ID: 84916613315

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

Subjective evaluation of Super Multi-View compressed contents on high-end light-field 3D displays

Super Multi-View (SMV) video content is composed of tens or hundreds of views that provide a light-field representation of a scene. This representation allows a glass-free visualization and eliminates many causes of discomfort existing in current available 3D video technologies. Efficient video compression of SMV content is a key factor for enabling future 3D video services. This paper first compares several coding configurations for SMV content and several inter-view prediction structures are also tested and compared. The experiments mainly suggest that large differences in coding efficiency can be observed from one configuration to another. Several ratios for the number of coded and synthesized views are compared, both objectively and subjectively. It is reported that view synthesis significantly affects the coding scheme. The amount of views to skip highly depends on the sequence and on the quality of the associated depth maps. Reported ranges of bitrates required to obtain a good quality for the tested SMV content are realistic and coherent with future 4. K/8. K needs. The reliability of the PSNR metric for SMV content is also studied. Objective and subjective results show that PSNR is able to reflect increase or decrease in subjective quality even in the presence of synthesized views. However, depending on the ratio of coded and synthesized views, the order of magnitude of the effective quality variation is biased by PSNR. Results indicate that PSNR is less tolerant to view synthesis artifacts than human viewers. Finally, preliminary observations are initiated. First, the light-field conversion step does not seem to alter the objective results for compression. Secondly, the motion parallax does not seem to be impacted by specific compression artifacts. The perception of the motion parallax is only altered by variations of the typical compression artifacts along the viewing angle, in cases where the subjective image quality is already low. To the best of our knowledge, this paper is the first to carry out subjective experiments and to report results of SMV compression for light-field 3D displays. It provides first results showing that improvement of compression efficiency is required, as well as depth estimation and view synthesis algorithms improvement, but that the use of SMV appears realistic according to next generation compression technology requirements.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Orange Labs, Holografika Kft., Pamany Peter Katolikus Egyetem
Contributors: Dricot, A., Jung, J., Cagnazzo, M., Pesquet, B., Dufaux, F., Kovács, P., Adhikarla, V. K.
Pages: 369–385
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: Signal Processing: Image Communication
Volume: 39
Issue number: Part B
ISSN (Print): 0923-5965
Ratings: 
  • Scopus rating (2015): CiteScore 4 SJR 0.532 SNIP 1.413
Original language: English
ASJC Scopus subject areas: Computer Vision and Pattern Recognition, Signal Processing, Software, Electrical and Electronic Engineering
Keywords: 3D, Light-field, Subjective evaluation, Super Multi-View, Video coding, Video compression
Source: Scopus
Source ID: 84947865722

Research output: Contribution to journalArticleScientificpeer-review

Low-complexity robust DOA estimation

We propose a low complexity method for estimating direction of arrival (DOA) when the positions of the array sensors are affected by errors with known magnitude bound. This robust DOA method is based on solving an optimization problem whose solution is obtained in two stages. First, the problem is relaxed and the corresponding power estimation has an expression similar to that of standard beamforming. If the relaxed solution does not satisfy the magnitude bound, an approximation is made by projection. Unlike other robust DOA methods, no eigenvalue decomposition is necessary and the complexity is similar to that of MVDR. For low and medium SNR, the proposed method competes well with more complex methods and is clearly better than MVDR.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Algebraic and Algorithmic Methods in Signal Processing AAMSP, Signal Processing Research Community (SPRC), Dept. of Automatic Control and Computers, University Politehnica of Bucharest
Contributors: Dumitrescu, B., Rusu, C., Tabus, I., Astola, J.
Number of pages: 5
Pages: 2794-2798
Publication date: 4 Aug 2015

Host publication information

Title of host publication: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
ISBN (Print): 9781467369978
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: direction of arrival, optimization, robustness, spectral power density
Source: Scopus
Source ID: 84946064969

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

Analytical model in discrete time for cross-layer video communication over LTE

Since video traffic is resource intensive, it is a challenging issue to stream video over low bandwidth networks, whereas video communication over LTE becomes an open research topic nowadays due to LTE’s high throughput capabilities. Indeed, video transmission requires low delay, and wireless channel is time-varying, which result in a scenario when a layer-separated design is replaced by a Cross-Layer Adaptation (CLA) principle. In this paper an efficient analytical model that evaluates the behavior of the downlink LTE channel with CLA is presented. To the best of our knowledge, this is the first time an analytical model using CLA principle has been devised that covers both the transmission process from the eNB to the User Equipment (UE) at the first phase and video decoding process at the UE at the second phase. In order to ensure the cross-layer adaptation in the model, the arrival rate varies based on the received video request, whereas the service probability changes according to the channel quality indicator sent from the UE. In the experimental part the analysis of the main performance measures found from the stationary distribution is conducted.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Video, Research Community on Data-to-Decision (D2D), Department of Telecommunication Systems, Peoples’ Friendship University of Russia
Contributors: Efimushkina, T., Gabbouj, M., Samuylov, K.
Number of pages: 13
Pages: 345-357
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: Automatic Control and Computer Sciences
Volume: 48
Issue number: 6
ISSN (Print): 0146-4116
Ratings: 
  • Scopus rating (2015): CiteScore 0.4 SJR 0.184 SNIP 0.561
Original language: English
ASJC Scopus subject areas: Signal Processing, Software, Control and Systems Engineering
Keywords: cross-layer adaptation, DASH, downlink, LTE, OFDMA, queuing system, stationary distribution
Source: Scopus
Source ID: 84920176216

Research output: Contribution to journalArticleScientificpeer-review

BM3D-HVS: Content-Adaptive denoising for improved visual quality

We introduce a content-Adaptive approach to image denoising where the filter design is based on mean opinion scores (MOSs) from preliminary experiments with volunteers who evaluated the quality of denoised image fragments. This allows to tune the filter parameters so to improve the perceptual quality of the output image, implicitly accounting for the peculiarities of the human visual system (HVS). A modification of the BM3D image denoising filter (Dabov et al., IEEE TIP, 2007), namely BM3DHVS, is proposed based on this framework. We show that it yields a higher visual quality than the conventional BM3D. Further, we have also analyzed the MOSs against popular full-reference visual quality metrics such as SSIM (Wang et al., IEEE TIP, 2004), its extension FSIM (Zhang et al., IEEE TIP, 2011), and the noreference IL-NIQE (Zhang et al., IEEE TIP, 2015) over each image fragment. Both the Spearman and the Kendall rank order correlation show that these metrics do not correspond well to the human perception. This calls for new visual quality metrics tailored for the benchmarking and optimization of image denoising methods.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing, Kharkiv National Aerospace University, Noiseless Imaging Ltd
Contributors: Egiazarian, K., Danielyan, A., Ponomarenkoa, N., Foia, A., Ieremeiev, O., Lukin, V.
Number of pages: 8
Pages: 48-55
Publication date: 2017

Host publication information

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

Publication series

Name: Electronic Imaging
ISSN (Print): 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

EXT="Danielyan, Aram"
EXT="Lukin, Vladimir"
jufoid=84313

Source: Scopus
Source ID: 85040604686

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

Guest editorial

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: System-on-Chip for GNSS, Wireless Communications and Cyber-Physical Embedded Computing, Department of Electronics and Communications Engineering
Contributors: Ellervee, P., Nurmi, J.
Number of pages: 2
Pages: 430-431
Publication date: 2013
Peer-reviewed: Yes

Publication information

Journal: Microprocessors and Microsystems
Volume: 37
Issue number: 4-5
ISSN (Print): 0141-9331
Ratings: 
  • Scopus rating (2013): CiteScore 1.6 SJR 0.225 SNIP 1.194
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software, Artificial Intelligence
Source: Scopus
Source ID: 84878614529

Research output: Contribution to journalArticleScientificpeer-review

Patterns for controlling chaos in a startup

A growing trend in industrial software engineering is that new software products and information services are developed under conditions of notable uncertainty. This is especially visible in startup enterprises which aim at new kinds of products and services in rapidly changing social web, where potential customers can quickly adopt new behavior. Special characteristics of the startups are lack of resources and funds, and startups may need to change direction fast. All these affect the software engineering practices used in the startups. Unfortunately almost 90 percent of all startups fail and goes bankrupt. There are probably indefinite numbers of reasons why startups fail. Failure might be caused by wrongly chosen software engineering practices or inconsiderate decision making. While there is no recipe for success, we argue that good practices that can help on the way to success can be identified from successful startups. In this paper, we present two patterns that startups can consider when entering the growth phase of the lifecycle.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing
Contributors: Eloranta, V.
Number of pages: 8
Pages: 1-8
Publication date: 10 Apr 2014

Host publication information

Title of host publication: VikingPLoP 2014 Proceedings of the 8th Nordic Conference on Pattern Languages of Programs
Volume: 2014-April
Publisher: Association for Computing Machinery
ISBN (Print): 9781450326605

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: Lean start-up, Organizational patterns, Patterns, Software engineering, Start-up
Source: Scopus
Source ID: 84940028558

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

Classification of large graphs by a local tree decomposition

We present a binary graph classifier (BGC) which allows to classify large, unweighted, undirected graphs. This classifier is based on a local decomposition of the graph for each node in generalized trees. The obtained trees, forming the tree set of the graph, are then pairwise compared by a generalized tree-similarity-algorithm (GTSA) and the resulting similarity scores determine a characteristic similarity distribution of the graph. Classification in this context is defined as mutual consistency for all pure and mixed tree sets and their resulting similarity distributions in a graph class. We demonstrate the application of this method to an artificially generated data set and for data from microarray experiments of cervical cancer.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Stowers Institute for Medical Research, Technical University Darmstadt
Contributors: Emmert-Streib, F., Dehmert, M., Kilian, J.
Number of pages: 8
Pages: 200-207
Publication date: 2005

Host publication information

Title of host publication: Proceedings of the 2005 International Conference on Data Mining, DMIN'05
ISBN (Print): 9781932415797
ASJC Scopus subject areas: Computer Science Applications, Software
Source: Scopus
Source ID: 49749142261

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

Fifty years of graph matching, network alignment and network comparison

In this paper we survey methods for performing a comparative graph analysis and explain the history, foundations and differences of such techniques of the last 50 years. While surveying these methods, we introduce a novel classification scheme by distinguishing between methods for deterministic and random graphs. We believe that this scheme is useful for a better understanding of the methods, their challenges and, finally, for applying the methods efficiently in an interdisciplinary setting of data science to solve a particular problem involving comparative network analysis.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing
Contributors: Emmert-Streib, F., Dehmer, M., Shi, Y.
Number of pages: 18
Pages: 180-197
Publication date: 10 Jun 2016
Peer-reviewed: Yes

Publication information

Journal: Information Sciences
Volume: 346-347
ISSN (Print): 0020-0255
Ratings: 
  • Scopus rating (2016): CiteScore 8.6 SJR 1.781 SNIP 2.515
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Software, Control and Systems Engineering, Theoretical Computer Science, Computer Science Applications, Information Systems and Management
Keywords: Biological networks, Computational graph theory, Graph matching, Network comparison, Network similarity, Quantitative graph theory
Source: Scopus
Source ID: 84964349574

Research output: Contribution to journalArticleScientificpeer-review

Compressive Sensing Image Restoration Using Adaptive Curvelet Thresholding and Nonlocal Sparse Regularization

Compressive sensing (CS) is a recently emerging technique and an extensively studied problem in signal and image processing, which suggests a new framework for the simultaneous sampling and compression of sparse or compressible signals at a rate significantly below the Nyquist rate. Maybe, designing an effective regularization term reflecting the image sparse prior information plays a critical role in CS image restoration. Recently, both local smoothness and nonlocal self-similarity have led to superior sparsity prior for CS image restoration. In this paper, first, an adaptive curvelet thresholding criterion is developed, trying to adaptively remove the perturbations appeared in recovered images during CS recovery process, imposing sparsity. Furthermore, a new sparsity measure called joint adaptive sparsity regularization (JASR) is established, which enforces both local sparsity and nonlocal 3-D sparsity in transform domain, simultaneously. Then, a novel technique for high-fidelity CS image recovery via JASR is proposed - CS-JASR. To efficiently solve the proposed corresponding optimization problem, we employ the split Bregman iterations. Extensive experimental results are reported to attest the adequacy and effectiveness of the proposed method comparing with the current state-of-the-art methods in CS image restoration.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Babol Noshirvani University of Technology
Contributors: Eslahi, N., Aghagolzadeh, A.
Number of pages: 15
Pages: 3126-3140
Publication date: 1 Jul 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Image Processing
Volume: 25
Issue number: 7
ISSN (Print): 1057-7149
Ratings: 
  • Scopus rating (2016): CiteScore 10.2 SJR 1.749 SNIP 3.397
Original language: English
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Software
Keywords: adaptive curvelet thresholding, Compressive sensing, nonlocal self-similarity, sparse recovery
Source: Scopus
Source ID: 84973121940

Research output: Contribution to journalArticleScientificpeer-review

An evaluation of the virtual curvature with the StickGrip haptic device: A case study

Dynamic simulation of distance to the physical surface could promote the development of new inexpensive tools for blind and visually impaired users. The StickGrip is a haptic device comprised of the Wacom pen input device added with a motorized penholder. The goal of the research presented in this paper was to assess the accuracy and usefulness of the new pen-based interaction technique when the position and displacement of the penholder in relation to the pen tip provided haptic feedback to the user about the distance to the physical or virtual surface of interaction. The aim was to examine how accurately people are able (1) to align the randomly deformed virtual surfaces to the flat surface and (2) to adjust the number of surface samples having a randomly assigned curvature to the template having the given curvature and kept fixed. These questions were approached by measuring both the values of the adjusted parameters and the parameters of the human performance, such as a ratio between inspection time and control time spent by the participants to complete the matching task with the use of the StickGrip device. The test of the pen-based interaction technique was conducted in the absence of visual feedback when the subject could rely on the proprioception and kinesthetic sense. The results are expected to be useful for alternative visualization and interaction with complex topographic and mathematical surfaces, artwork, and modeling.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Augmented Human Activities (AHA)
Contributors: Evreinova, T. V., Evreinov, G., Raisamo, R.
Number of pages: 13
Pages: 161-173
Publication date: Jun 2013
Peer-reviewed: Yes

Publication information

Journal: Universal Access in the Information Society
Volume: 12
Issue number: 2
ISSN (Print): 1615-5289
Ratings: 
  • Scopus rating (2013): CiteScore 2.6 SJR 0.513 SNIP 1.516
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Networks and Communications, Human-Computer Interaction
Keywords: Curved surface, Kinesthetic feedback, Pen-based interaction, StickGrip haptic device
Source: Scopus
Source ID: 84878407340

Research output: Contribution to journalArticleScientificpeer-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

Haptic user interface enhancement system for touchscreen based interaction: A novel system for multimodal interaction with touchscreen interfaces

Touchscreens are becoming a more attractive interaction technology in our daily lives and they are quickly replacing most of the conventional user interface controls. The ability to continuously modify and reconfigure screen contacts is a valuable feature in any device, especially in mobile devices like smartphones and tablets, where every inch matters. Perhaps the most inviting aspect of touchscreens is their ability to detect gestures and recognize human activities. Unlike externally static interfaces with a dedicated input device, such as a keypad with discrete well-defined keys; most touch sensitive displays are embodied as a flat, stiff and ridged screen surface. As a result, touch sensitive displays are breaking down and do not follow either ergonomic rules and standards nor physiological and psychological models/concepts of the afferent flow information processing. This, in turn, means that these systems diminish perceptual and intuitive haptic feedback which hinders and sometime limits user interaction.This paper defines a Haptic User Interface Enhancement System (UIES) that transforms the conventionally flat and stiff touchscreen surfaces intoa haptically adaptive interaction hub which is not only able to provide generic vibrotactile stimulation for conformational haptic feedback but is able to guide the user though onscreen User Interface controls via kinetic feedback cues which includes components of forces and torques applied dynamically in the place of contact to the fingertips.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA)
Contributors: Farooq, A., Evreinov, G., Raisamo, R., Majeed, A. A.
Number of pages: 7
Pages: 25-31
Publication date: 2 Feb 2014

Host publication information

Title of host publication: ICOSST 2014 - 2014 International Conference on Open Source Systems and Technologies, Proceedings
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 7029316
ISBN (Electronic): 9781479920549
ASJC Scopus subject areas: Computer Science Applications, Software
Keywords: Haptics, kenesthetic feedback, Multimodal Interaction, Touchscreen Interaction, Vibrotactile
Source: Scopus
Source ID: 84946686310

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

Developing novel multimodal interaction techniques for touchscreen in-vehicle infotainment systems

Haptics has been an integral part of multimodal systems in Human Computer Interaction (HCI). The ability to touch and sense virtual components of any system has long been the holy grail of HCI, which is particularly useful in mission critical environments where other modalities are weakened by environmental noise. Haptics also compliments most modalities of interaction by reinforcing the intimate and personal aspect of interaction. Haptics becomes much more important in environments that prove to be far too noisy for audio feedback.The driving environment is one such area, which the addition of haptics is not just additive, but critical in HCI. However, most of the research on haptic feedback in the car has been conducted using vibro-tactile feedback. In this paper, we present a system in which we have developed a novel haptic feedback environment using pneumatic and vibrotactile technologies, to facilitate in carcommunication, using the In-vehicle Infotainment System. Our aim was to build on the user haptic perception and experience the advance multimodal interaction system by utilizing available feedback techniques in, in-car interaction. The qualitative results of our study show that haptic feedback has great potential for safety and communication use, but the difficulty in interpreting haptic signals requires additional translation means ('semantic linkages'), to support the right interpretation of the haptic information.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA)
Contributors: Farooq, A., Evreinov, G., Raisamo, R., Mäkinen, E., Nukarinen, T., Majeed, A. A.
Number of pages: 11
Pages: 32-42
Publication date: 2 Feb 2014

Host publication information

Title of host publication: ICOSST 2014 - 2014 International Conference on Open Source Systems and Technologies, Proceedings
Publisher: Institute of Electrical and Electronics Engineers Inc.
Article number: 7029317
ISBN (Electronic): 9781479920549
ASJC Scopus subject areas: Computer Science Applications, Software
Keywords: haptic feedback, human computer iteraction, In-Vehicle Infotainment Systems, Multimodal Interaction, pneumatic feedback, tactile/vibro-tactile feedback
Source: Scopus
Source ID: 84946688361

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

Power allocation in multi-node cooperative network in Rician fading channels

Cooperative communications have been recommended to exploit the inherent spatial diversity gains in multiuser wireless systems without the need of multiple transceivers at each node. This is achieved when wireless nodes help to each other to send multiple independent transmission paths to the destination. The advantage of cooperation can be exploited significantly by allocating the power of the system optimally. Thus, in this paper we first derive the approximate symbol error rate (SER) for multi-node cooperative networks employing decode-and-forward (DF) protocol with a maximum ratio combining (MRC) at the receiving terminals in Racian fading channels. Using the approximated SER expression, optimal power allocation (OPA) scheme under different line-of-sight (LOS) scenarios is investigated. Numerical and simulation results are presented to illustrate the performance improvement due to OPA of the cooperative networks.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Wireless Communications and Positioning (WICO), Department of Computer Science, University of Vaasa (UVA)
Contributors: Fikadu, M. K., Elmusrati, M., Virrankoski, R.
Number of pages: 6
Pages: 496-501
Publication date: 2012

Host publication information

Title of host publication: 2012 IEEE 8th International Conference on Wireless and Mobile Computing, Networking and Communications, WiMob 2012
Article number: 6379119
ISBN (Print): 9781467314305
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software
Keywords: Cooperative, decode-and-forward, multi-node, optimal power allocation, Rician fading, SER analysis
Source: Scopus
Source ID: 84872085066

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

Foveated Nonlocal Self-Similarity

When we gaze a scene, our visual acuity is maximal at the fixation point (imaged by the fovea, the central part of the retina) and decreases rapidly towards the periphery of the visual field. This phenomenon is known as foveation. We investigate the role of foveation in nonlocal image filtering, installing a different form of self-similarity: the foveated self-similarity. We consider the image denoising problem as a simple means of assessing the effectiveness of descriptive models for natural images and we show that, in nonlocal image filtering, the foveated self-similarity is far more effective than the conventional windowed self-similarity. To facilitate the use of foveation in nonlocal imaging algorithms, we develop a general framework for designing foveation operators for patches by means of spatially variant blur. Within this framework, we construct several parametrized families of operators, including anisotropic ones. Strikingly, the foveation operators enabling the best denoising performance are the radial ones, in complete agreement with the orientation preference of the human visual system.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research area: Signal and Information Processing, Research group: Signal and Image Restoration-RST, Dipartimento di Elettronica, Politecnico di Milano
Contributors: Foi, A., Boracchi, G.
Number of pages: 33
Pages: 78–110
Publication date: 2016
Peer-reviewed: Yes
Early online date: 9 Mar 2016

Publication information

Journal: International Journal of Computer Vision
Volume: 120
Issue number: 1
ISSN (Print): 0920-5691
Ratings: 
  • Scopus rating (2016): CiteScore 17.4 SJR 6.779 SNIP 5.171
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition
Electronic versions: 
URLs: 

Bibliographical note

EXT="Boracchi, Giacomo"

Source: Scopus
Source ID: 84960153979

Research output: Contribution to journalArticleScientificpeer-review

Email intensity, productivity and control in the knowledge worker's performance on the desktop

Experiencing stress, disturbing interruptions, loss of ability to concentrate, hurry and challenges to meet tight deadlines at work are very common in working life. At the same time, while variety of digital communication channels like instant messaging, video calls and social networking sites are getting more popular in working life, email is still intensively utilized work communication media. The goal of the empirical field study analyzing daily desktop computing of knowledge workers was to analyze association between email intensity in work time spending and subjectively experienced quality of work performance. It was found that while intensive email use does not impair subjectively experienced productivity, it may harm ability to concentrate, may increase forgetfulness and inability to solve problems at work effectively. Copyright is held by the owner/author(s). Publication rights licensed to ACM.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), University of Tampere
Contributors: Franssila, H., Okkonen, J., Savolainen, R.
Number of pages: 4
Pages: 19-22
Publication date: 4 Nov 2014

Host publication information

Title of host publication: MINDTREK 2014 - Proceedings of the 18th International Academic MindTrek Conference: "Media Business, Management, Content and Services"
Publisher: Association for Computing Machinery, Inc
ISBN (Electronic): 9781450330060
ASJC Scopus subject areas: Computer Science Applications, Human-Computer Interaction, Software
Keywords: Email intensity, Knowledge work, Measurement, Productivity, Work performance
Source: Scopus
Source ID: 84964078815

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

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

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

Gestures and widgets: Performance in text editing on multi-touch capable mobile devices

We describe the design and evaluation of a gestural text editing technique for touchscreen devices. The gestures are drawn on top of the soft keyboard and interpreted as commands for moving the caret, performing selections, and controlling the clipboard. Our implementation is an Android service that can be used in any text editing task on Android-based devices. We conducted an experiment to compare the gestural editing technique against the widget-based technique available on a smartphone (Samsung Galaxy II with Android 2.3.5). The results show a performance benefit of 13-24% for the gestural technique depending on the font size. Subjective feedback from the participants was also positive. Because the two editing techniques use different input areas, they can coexist on a device. This means that the gestural editing can be added on any soft keyboard without interfering with user experience for those users that choose not to use it.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), Università di Salerno, Université de Lorraine
Contributors: Fuccella, V., Isokoski, P., Martin, B.
Number of pages: 10
Pages: 2785-2794
Publication date: 2013

Host publication information

Title of host publication: CHI 2013: Changing Perspectives, Conference Proceedings - The 31st Annual CHI Conference on Human Factors in Computing Systems
ISBN (Print): 9781450318990
ASJC Scopus subject areas: Human-Computer Interaction, Computer Graphics and Computer-Aided Design, Software
Keywords: Android, Caret movement, Clipboard, Gestures, Text editing
Source: Scopus
Source ID: 84877966468

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

On the Architecture of Liquid Software: Technology Alternatives and Design Space

The liquid metaphor refers to software that operates seamlessly across multiple devices owned by one or multiple users. Liquid software architectures can dynamically deploy and redeploy stateful software components and transparently adapt them to the capabilities of heterogeneous target devices. The key design goal in liquid software development is to minimize the efforts that are related to multiple device ownership (e.g., installation, synchronization and general maintenance of personal computers, smartphones, tablets, home displays, cars and wear-able devices), while keeping the users in full control of their devices, applications and data. In this paper we present a design space for liquid software, categorizing and discussing the most important architectural issues and alternatives. These alternatives represent relevant capabilities offered by emerging technologies and deployment platforms that are then positioned and compared within the design space presented in the paper.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: Software engineering, University of Lugano (USI), Nokia Technologies
Contributors: Gallidabino, A., Pautasso, C., Ilvonen, V., Mikkonen, T., Systä, K., Voutilainen, J., Taivalsaari, A.
Number of pages: 6
Pages: 122-127
Publication date: 19 Jul 2016

Host publication information

Title of host publication: Proceedings - 2016 13th Working IEEE/IFIP Conference on Software Architecture, WICSA 2016
Publisher: IEEE
ISBN (Electronic): 9781509021314
ASJC Scopus subject areas: Hardware and Architecture, Software
Keywords: design space, liquid software, Multi-device programming, multiple device owner-ship, software architecture

Bibliographical note

EXT="Taivalsaari, Antero"

Source: Scopus
Source ID: 84983317329

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

An Assessment of Errors and Their Reduction in Terrestrial Laser Scanner Measurements in Marmorean Surfaces

The need for accurate documentation for the preservation of cultural heritage has prompted the use of terrestrial laser scanner (TLS) in this discipline. Its study in the heritage context has been focused on opaque surfaces with lambertian reflectance, while translucent and anisotropic materials remain a major challenge. The use of TLS for the mentioned materials is subject to significant distortion in measure due to the optical properties under the laser stimulation. The distortion makes the measurement by range not suitable for digital modelling in a wide range of cases. The purpose of this paper is to illustrate and discuss the deficiencies and their resulting errors in marmorean surfaces documentation using TLS based on time-of-flight and phase-shift. Also proposed in this paper is the reduction of error in depth measurement by adjustment of the incidence laser beam. The analysis is conducted by controlled experiments.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: School of Architecture
Contributors: Garcia-Fernandez, J.
Number of pages: 11
Pages: 1-11
Publication date: 1 Mar 2016
Peer-reviewed: Yes

Publication information

Journal: 3D Research
Volume: 7
Issue number: 1
Article number: 2
ISSN (Print): 2092-6731
Ratings: 
  • Scopus rating (2016): CiteScore 1.3 SJR 0.166 SNIP 0.425
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Software
Keywords: Comparison, Experimental, Laser scanning, Marble, Measurement, Translucency
Source: Scopus
Source ID: 84955495304

Research output: Contribution to journalArticleScientificpeer-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

Analysis of a receiver-based reliable broadcast approach for vehicular networks

The Intelligent Transportation Systems concept provides the ground to enable a wide range of applications to improve traffic safety and efficiency. Innovative communication systems must be proposed taking into account, on the one hand, unstable characteristics of vehicular communications and, on the other hand, different requirements of applications. In this paper a reliable (geo-)broadcasting scheme for vehicular ad-hoc networks is proposed and analyzed. This receiver-based technique aims at fulfilling the received message integrity yet keeping the overhead at a reasonably low level. The results are compared to simulation studies carried out in the Network Simulator-3 (NS-3) simulation environment demonstrating good agreement with each other. The analysis shows that in a single-hop scenario, receiver-based reliable broadcasting can provide good reliability, while giving very little overhead for high number of receivers.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, University of Twente
Contributors: Gholibeigi, M., Heijenk, G., Moltchanov, D., Koucheryavy, Y.
Number of pages: 13
Pages: 63-75
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Ad Hoc Networks
Volume: 37
ISSN (Print): 1570-8705
Ratings: 
  • Scopus rating (2016): CiteScore 6.1 SJR 0.648 SNIP 2.045
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software
Keywords: (Geo)Broadcast, Performance modeling, Reliability, Vehicular ad hoc networks
Source: Scopus
Source ID: 84947868264

Research output: Contribution to journalArticleScientificpeer-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

Comparison of video-based pointing and selection techniques for hands-free text entry

Video-based human-computer interaction has received increasing interest over the years. However, earlier research has been mainly focusing on technical characteristics of different methods rather than on user performance and experiences in using computer vision technology. This study aims to investigate performance characteristics of novice users and their subjective experiences in typing text with several video-based pointing and selection techniques. In Experiment 1, eye tracking and head tracking were applied for the task of pointing at the keys of a virtual keyboard. The results showed that gaze pointing was significantly faster but also more erroneous technique as compared with head pointing. Self-reported subjective ratings revealed that it was generally better, faster, more pleasant and efficient to type using gaze pointing than head pointing. In Experiment 2, mouth open and brows up facial gestures were utilized for confirming the selection of a given character. The results showed that text entry speed was approximately the same for both selection techniques, while mouth interaction caused significantly fewer errors than brow interaction. Subjective ratings did not reveal any significant differences between the techniques. Possibilities for design improvements are discussed.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA)
Contributors: Gizatdinova, Y., Špakov, O., Surakka, V.
Number of pages: 8
Pages: 132-139
Publication date: 2012

Host publication information

Title of host publication: Proceedings of the Working Conference on Advanced Visual Interfaces, AVI 2012
ISBN (Print): 9781450312875
ASJC Scopus subject areas: Software, Human-Computer Interaction
Keywords: computer vision, eye tracking, face detection, text entry, video-based interaction, virtual keyboard, visual gesture
Source: Scopus
Source ID: 84863593939

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

Facial expression classification based on local spatiotemporal edge and texture descriptors

Facial expressions are emotionally, socially and otherwise meaningful reflective signals in the face. Facial expressions play a critical role in human life, providing an important channel of nonverbal communication. Automation of the entire process of expression analysis can potentially facilitate human-computer interaction, making it to resemble mechanisms of human-human communication. In this paper, we present an ongoing research that aims at development of a novel spatiotemporal approach to expression classification in video. The novelty comes from a new facial representation that is based on local spatiotemporal feature descriptors. In particular, a combined dynamic edge and texture information is used for reliable description of both appearance and motion of the expression. Support vector machines are utilized to perform a final expression classification. The planned experiments will further systematically evaluate the performance of the developed method with several databases of complex facial expressions.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), Univ of Oulu
Contributors: Gizatdinova, Y., Surakka, V., Zhao, G., Mäkinen, E., Raisamo, R.
Publication date: 2011

Host publication information

Title of host publication: Selected Papers from the Proceedings of the 7th International Conference on Methods and Techniques in Behavioral Research - Digital Edition, MB'10
Article number: 21
ISBN (Print): 9781605589268
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Action unit, Emotion, Expression classification, Facial expression, Human behaviour understanding, Local binary pattern, Local oriented edge, Spatiotemporal descriptor
Source: Scopus
Source ID: 79952499491

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

Software architectures for implementing achievement badges - Practical experiences

There are multiple commercial and non-commercial products available to integrate gamification aspects to existing services. Some of these are platform dependent whilst others are more general purpose. Commercial systems come with some problems - for example, lack of control and privacy issues. To avoid these problems, we created two iterations of badge systems and tested both of them on large courses (ca. 300 students each). In this paper, we present these systems and evaluate their merits and flaws. Based on our experiences, we present design principles on how to implement badge systems to existing online learning environments.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Regulation of learning and active learning methods (REALMEE), Aalto University, Department of Computer Science and Eng.
Contributors: Haaranen, L., Hakulinen, L., Ihantola, P., Korhonen, A.
Number of pages: 6
Pages: 41-46
Publication date: 2014

Host publication information

Title of host publication: Proceedings - 2014 International Conference on Teaching and Learning in Computing and Engineering, LATICE 2014
Publisher: IEEE COMPUTER SOCIETY PRESS
Article number: 6821826
ISBN (Print): 9781479935918
ASJC Scopus subject areas: Software
Keywords: Achievement badges, Automated assessment, Gamification, System design
Source: Scopus
Source ID: 84903453777

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

Reducing the number of unit tests with design by contract

Design by Contract (DbC) and unit testing (UT) are complementary approaches to improve the belief of correctness and the quality of the software. The interplay between the two techniques has been studied previously, e.g., in the use of test oracles and test automation. However, we propose that DbC should drive the UT to become more cost-effective. The paper demonstrates some means for this approach by showing how to test a mapping data structure entirely with just one unit test script.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Managing digital industrial transformation (mDIT), Department of Information Technology, Turku Centre for Computer Science, University of Turku
Contributors: Hakonen, H., Hyrynsalmi, S., Järvi, A.
Number of pages: 6
Pages: 161-166
Publication date: 2011

Host publication information

Title of host publication: Computer Systems and Technologies - 12th International Conference, CompSysTech'11 - Proceedings
Volume: 578
ISBN (Print): 9781450309172
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: contract cohesion graph, design by contract, unit testing
Source: Scopus
Source ID: 80052810613

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

Framework for designing and evaluating game achievements

This paper presents a framework for evaluating and designing game design patterns commonly called as "achievements". The results are based on empirical studies of a variety of popular achievement systems. The results, along with the framework for analyzing and designing achievements, present two definitions of game achievements. From the perspective of the achievement system, an achievement appears as a challenge consisting of a signifying element, rewards and completion logics whose fulfilment conditions are defined through events in other systems (usually games). From the perspective of a single game, an achievement appears as an optional challenge provided by a meta-game that is independent of a single game session and yields possible reward(s).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Mathematical modelling with wide societal impact (MathImpact), Aalto University, University of Helsinki
Contributors: Hamari, J., Eranti, V.
Publication date: 2011

Host publication information

Title of host publication: Proceedings of DiGRA 2011 Conference: Think Design Play
ASJC Scopus subject areas: Computer Graphics and Computer-Aided Design, Human-Computer Interaction, Software
Keywords: Game achievements, Game design, Game ontology, Game rewards, Gamification, Marketing, Motivation, Online games
Source: Scopus
Source ID: 84873368072

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

Managing concern knowledge in software systems

Knowledge representation, acquisition, and sharing in software development projects is challenging due to the involvement of different kinds of stakeholders and large heterogeneous repositories of artifacts. In this paper, we argue that the concept of a concern can be used to facilitate the management of knowledge concerning the various system artifacts. Concerns represent pieces of knowledge pertaining to various viewpoints and interests of the stakeholders. In order to represent concerns, we propose the use of a non-intrusive role-based mechanism called a fragment. Using this mechanism, tacit knowledge can be made explicit by mapping stakeholders interests to artifact repositories, concern-based queries can be addressed to the repositories, and concerns can be combined to produce new knowledge. A concern-based prototype tool environment for knowledge management has been built and used for evaluating the approach in the context of industrial case studies.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Pervasive Computing, Managing digital industrial transformation (mDIT)
Contributors: Hammouda, I., Koskimies, K., Mikkonen, T.
Number of pages: 31
Pages: 957-987
Publication date: Nov 2011
Peer-reviewed: Yes

Publication information

Journal: INTERNATIONAL JOURNAL OF SOFTWARE ENGINEERING AND KNOWLEDGE ENGINEERING
Volume: 21
Issue number: 7
ISSN (Print): 0218-1940
Ratings: 
  • Scopus rating (2011): CiteScore 1 SJR 0.19 SNIP 0.482
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Graphics and Computer-Aided Design, Computer Networks and Communications
Keywords: Knowledge management, Separation of concerns, Software development tools, Software repositories
Source: Scopus
Source ID: 84856103523

Research output: Contribution to journalArticleScientificpeer-review

Social behavior in bacterial nanonetworks: Challenges and opportunities

Molecular communication holds the promise to enable communication between nanomachines with a view to increasing their functionalities and opening up new possible applications. Due to some of the biological properties, bacteria have been proposed as a possible information carrier for molecular communication, and the corresponding communication networks are known as bacterial nanonetworks. The biological properties include the ability for bacteria to mobilize between locations and carry the information encoded in deoxyribonucleic acid molecules. However, similar to most organisms, bacteria have complex social properties that govern their colony. These social characteristics enable the bacteria to evolve through various fluctuating environmental conditions by utilizing cooperative and non-cooperative behaviors. This article provides an overview of the different types of cooperative and non-cooperative social behavior of bacteria. The challenges (due to non-cooperation) and the opportunities (due to cooperation) these behaviors can bring to the reliability of communication in bacterial nanonetworks are also discussed. Finally, simulation results on the impact of bacterial cooperative social behavior on the end-to-end reliability of a single-link bacterial nanonetwork are presented. The article concludes by highlighting the potential future research opportunities in this emerging field.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Wireless Communications and Positioning (WICO), University of Manitoba
Contributors: Hasan, M., Hossain, E., Balasubramaniam, S., Koucheryavy, Y.
Number of pages: 9
Pages: 26-34
Publication date: 1 Jan 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Network
Volume: 29
Issue number: 1
Article number: 7018200
ISSN (Print): 0890-8044
Ratings: 
  • Scopus rating (2015): CiteScore 7.9 SJR 1.107 SNIP 2.903
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Information Systems, Software
Source: Scopus
Source ID: 84921862364

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

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

Programmable lowpower implementation of the HEVC Adaptive Loop Filter

The Adaptive Loop Filter (ALF) is a subjective and objective image quality improving filter in the High Efficiency Video Coding standard (HEVC). The ALF has shown to be computationally complex and its complexity has been reduced during the HEVC development process. In the HEVC TestModel HM-7.0 ALF is a 9×7 cross + 3×3 square shaped filter. This paper presents a programmable application specific instruction processor for the ALF. The proposed processor processes 1920×1080p luminance frames at 30 frames per second, when operated at a clock frequency of 311MHz. Low power consumption and a low gate count make the proposed processor suitable for embedded devices. The processor program code is written in pure C-language, which allows versatile use of the circuit and updates to the filter functionality without modifying the processor design. To the authors' best knowledge this is the first programmable solution for ALF on embedded devices.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Signal Processing Research Community (SPRC), Univ of Oulu, Dept. of Computer Science and Engineering
Contributors: Hautala, I., Boutellier, J., Hannuksela, J.
Number of pages: 5
Pages: 2664-2668
Publication date: 18 Oct 2013

Host publication information

Title of host publication: 2013 IEEE International Conference on Acoustics, Speech, and Signal Processing, ICASSP 2013 - Proceedings
Article number: 6638139
ISBN (Print): 9781479903566
ASJC Scopus subject areas: Software, Signal Processing, Electrical and Electronic Engineering
Keywords: Adaptive filters, Coprocessors, Video signal processing
Source: Scopus
Source ID: 84890508061

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

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

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

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

Quality measures for improving technology trees

The quality of technology trees in digital games can be improved by adjusting their structural and quantitative properties. Therefore, there is a demand for recognizing and measuring such properties. Part of the process can be automated; there are properties measurable by computers, and analyses based on the results (and visualizations of them) may help to produce significantly better technology trees, even practically without extra workload for humans. In this paper, we introduce useful technology tree properties and novel measuring features implemented into our sofware tool for manipulating technology trees.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Mathematics, Research group: MAT Computer Science and Applied Logics
Contributors: Heinimäki, T. J., Elomaa, T.
Number of pages: 10
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: International Journal of Computer Games Technology
Volume: 2015
Article number: 975371
ISSN (Print): 1687-7047
Ratings: 
  • Scopus rating (2015): CiteScore 1 SJR 0.204 SNIP 0.366
Original language: English
ASJC Scopus subject areas: Human-Computer Interaction, Software, Computer Graphics and Computer-Aided Design
Source: Scopus
Source ID: 84929378426

Research output: Contribution to journalArticleScientificpeer-review

Augmenting Technology Trees: Automation and Tool Support

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Mathematics, Research group: MAT Computer Science and Applied Logics
Contributors: Heinimäki, T. J., Elomaa, T.
Number of pages: 8
Pages: 68-75
Publication date: Sep 2015

Host publication information

Title of host publication: Proceedings of the Seventh International Conference on Virtual Worlds and Games for Serious Applications (VS-Games 2015)
Publisher: IEEE
ISBN (Print): 978-1-4799-8101-4
ISBN (Electronic): 978-1-4799-8102-1
ASJC Scopus subject areas: Software

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

Learnings from the Finnish game industry

The motivation behind our research was the rapid growth and business wins of world-class Finnish game companies, like Supercell, as well as the success of other game companies in Finland. In particular, Supercell's growth is something that has not been heard of before and this raised the interest to research what game companies have been doing right. Supercell is not the only Finnish success. Rovio is also well known and has the roots for success from few years before. There are also other game companies in Finland that have succeeded and this motivated us to investigate what is happening behind the game industry and what could be learned from there that could be applied to other software industry as well. In order to explore and explain the different success factors, we interviewed the following eight Finnish game companies: Rovio Entertainment, Fingersoft, TicBits, Boomlagoon, 10tons, Tribeflame, Star Arcade and Mountain Sheep. In addition, we investigated public sources, like interviews given to newspapers and books written about companies. These sources cover well Supercell as they have given numerous public interviews to journalists. Similarly, Remedy was analysed based on public sources. Based on the results we recognised some 30 patterns that, depending on the context, could be used in other organisations as well. The patterns include the applicable context where they can be used, driving forces (and counterforces) that should be recognised, the problem they are solving and the solution to the problem coupled with the key enablers. Furthermore, narrative stories based on the interviews and public sources are included.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing, Research area: Information security, University of Helsinki, Jyväskylän yliopisto
Contributors: Helenius, M., Kettunen, P., Frank, L.
Publication date: 7 Apr 2016

Host publication information

Title of host publication: Proceedings of the 10th Travelling Conference on Pattern Languages of Programs, VikingPLoP 2016
Publisher: ACM
Article number: a12
ISBN (Electronic): 9781450342001
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software

Bibliographical note

EXT="Frank, Lauri"

Source: Scopus
Source ID: 85015616047

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

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

Recording and analyzing in-browser programming sessions

In this paper, we report on the analysis of a novel type of automatically recorded detailed programming session data collected on a university-level web programming course. We present a method and an implementation of collecting rich data on how students learning to program edit and execute code and explore its use in examining learners' behavior. The data collection instrument is an in-browser Python programming environment that integrates an editor, an execution environment, and an interactive Python console and is used to deliver programming assignments with automatic feedback. Most importantly, the environment records learners' interaction within it. We have implemented tools for viewing these traces and demonstrate their potential in learning about the programming processes of learners and of benefiting computing education research and the teaching of programming.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Regulation of learning and active learning methods (REALMEE), Aalto University, Department of Computer Science and Eng.
Contributors: Helminen, J., Ihantola, P., Karavirta, V.
Number of pages: 10
Pages: 13-22
Publication date: 2013

Host publication information

Title of host publication: Proceedings - 13th Koli Calling International Conference on Computing Education Research, Koli Calling 2013
ISBN (Print): 9781450324823
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: computer science education, computing education research, programming assignment, programming session, Python, web based programming environment
Source: Scopus
Source ID: 84889581968

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

Participatory development of user experience design guidelines for a B2B company

As business success is increasingly dependent on an organization's ability to provide a pleasant user experiences (UX) for its products, companies need to find ways to harness every employee to think about UX in their daily work. To support this goal, we present a participatory development process to create user experience design guidelines for a company developing materials-handling equipment for warehouses. The guidelines were developed to steer the work of all R&D designers and developers towards experience-driven design of the products in business-to-business context. The participatory process includes six steps: Spreading awareness of UX within the company, providing information on UX, supporting understanding of UX, co-creation of guidelines, reviewing the outcome, and implementing the guidelines. This paper concentrates on describing the first five phases. The participatory approach is applicable by other organizations to support the change towards experience-driven design. The process and outcome aims to support employees' everyday work aiming for products with pleasant UX.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience, Rocla Oy, Aalto University
Contributors: Hildén, E., Väätäjä, H., Roto, V., Uusitalo, K.
Number of pages: 10
Pages: 49-58
Publication date: 17 Oct 2016

Host publication information

Title of host publication: AcademicMindtrek '16 Proceedings of the 20th International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 978-1-4503-4367-1
ASJC Scopus subject areas: Human-Computer Interaction, Software, Computer Science Applications
Keywords: B2B, Design, Guideline, Mindset, Organizational change, Participatory Design, User experience

Bibliographical note

EXT="Roto, Virpi"

Source: Scopus
Source ID: 84994834980

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

Automatic image-based detection and inspection of paper fibres for grasping

An automatic computer vision algorithm that detects individual paper fibres from an image, assesses the possibility of grasping the detected fibres with microgrippers and detects the suitable grasping points is presented. The goal of the algorithm is to enable automatic fibre manipulation for mechanical characterisation, which has traditionally been slow manual work. The algorithm classifies the objects in images based on their morphology, and detects the proper grasp points from the individual fibres by applying given geometrical constraints. The authors test the ability of the algorithm to detect the individual fibres with 35 images containing more than 500 fibres in total, and also compare the graspability analysis and the calculated grasp points with the results of an experienced human operator with 15 images that contain a total of almost 200 fibres. The detection results are outstanding, with fewer than 1% of fibres missed. The graspability analysis gives sensitivity of 0.83 and specificity of 0.92, and the average distance between the grasp points of the human and the algorithm is 220 μm. Also, the choices made by the algorithm are much more consistent than the human choices.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Automation Science and Engineering, Integrated Technologies for Tissue Engineering Research (ITTE)
Contributors: Hirvonen, J., Kallio, P.
Number of pages: 7
Pages: 588-594
Publication date: 1 Aug 2015
Peer-reviewed: Yes

Publication information

Journal: IET Computer Vision
Volume: 9
Issue number: 4
ISSN (Print): 1751-9632
Ratings: 
  • Scopus rating (2015): CiteScore 2.3 SJR 0.3 SNIP 1.218
Original language: English
ASJC Scopus subject areas: Computer Vision and Pattern Recognition, Software
Electronic versions: 
Source: Scopus
Source ID: 84938530267

Research output: Contribution to journalArticleScientificpeer-review

Squeeze vs. tilt: A comparative study using continuous tactile feedback

This paper presents an investigation into the performance of squeezing as a manipulative interaction technique in comparison to tilting with an aim to answer two questions: is squeezing an effective input technique for mobile devices and can tactile feedback improve performance? The experiment results show that both input methods are viable but squeezing is significantly faster and more sustainable than tilting (with and without tactile feedback).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), Nokia
Contributors: Hoggan, E., Trendafilov, D., Ahmaniemi, T., Raisamo, R.
Number of pages: 6
Pages: 1309-1314
Publication date: 2011

Host publication information

Title of host publication: CHI EA 2011 - 29th Annual CHI Conference on Human Factors in Computing Systems, Conference Proceedings and Extended Abstracts
ISBN (Print): 9781450302289
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Graphics and Computer-Aided Design
Keywords: Haptic I/O, Mobile interaction, Pressure, Squeeze
Source: Scopus
Source ID: 79957943879

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

Three patterns for user involvement in startups

Creating products in software startups consists of a great deal of uncertainty combined with little resources. Rapid validation of created solutions with the potential customers is essential to startups. However, often startups lack people with skills needed for the validation. We present three patterns that help in involving users to gain meaningful feedback and learning. First, the feedback has to be gotten from the right people and the right questions have to be asked. Furthermore, if the feedback is collected with a prototype, often called a Minimum Viable Product, users should be able to give feedback of the actual idea, not to any roughness caused by the immaturity and the prototypishness of the product.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: Software engineering
Contributors: Hokkanen, L., Leppänen, M.
Publication date: 8 Jul 2015

Host publication information

Title of host publication: Proceedings of the 20th European Conference on Pattern Languages of Programs, EuroPLoP 2015
Publisher: ACM
Article number: a51
ISBN (Electronic): 9781450338479
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Lean, Startups, User experience
Source: Scopus
Source ID: 84982794686

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

Focusing on user experience and business models in startups: Investigation of two-dimensional value creation

While good user experience (UX) can be seen to provide competitive advantage for the company and added value to users, resources for achieving UX may often be lacking in software startups. Furthermore, in different phases of business and product development process, concentrating on the focal things can be challenging. In this study, we investigated the factors affecting UX work in startups as well as UX goals startups set for their products. Furthermore, we reviewed the goals in terms of the Minimum Viable UX framework as well as value creation aspects. We present qualitative results of a survey study with 20 software startups as well as findings of a literature review. Our study suggests that while startups aim to provide products with good usability, the lack of a more comprehensive approach to UX can hinder their value creation; affecting both user satisfaction and business success. As a result, this may affect the successful implementation of startup's business model.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research area: User experience, Department of Pervasive Computing, University of Oulu
Contributors: Hokkanen, L., Xu, Y., Väänänen, K.
Number of pages: 9
Pages: 59-67
Publication date: 17 Oct 2016

Host publication information

Title of host publication: AcademicMindtrek 2016 - Proceedings of the 20th International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450343671
ASJC Scopus subject areas: Human-Computer Interaction, Software, Computer Science Applications
Keywords: Business model, Software, Startup, User experience, Value
Source: Scopus
Source ID: 84994831715

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

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

Social and privacy aspects of a system for collaborative public expression

In this paper, we are concerned with how a real-world social situation shapes the interaction with a novel technology that combines collocated mobile phone and public display use for groups of people. We present a user study of a system that allows collaborative creation and sharing of comic strips on public displays in a social setting such as a pub or café. The system utilizes mobile phones and public displays for shared collaborative expression between collocated users. A user study spanning three sessions was conducted in real-world settings: one during the social event following a seminar on games research and two in a bar on a regular weekday evening. We present and discuss our findings with respect to how the larger social situation and location influenced the interaction with the system, the collaboration between participants of a team, how people moved between different roles (i.e., actor, spectator and bystander), and the privacy issues it evoked from participants.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Mathematical modelling with wide societal impact (MathImpact), Nokia
Contributors: Holopainen, J., Lucero, A., Saarenpää, H., Nummenmaa, T., Ali, A. E., Jokela, T.
Publication date: 2011

Host publication information

Title of host publication: Proceedings of the 8th International Conference on Advances in Computer Entertainment Technology, ACE 2011
Article number: 23
ISBN (Print): 9781450308274
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Collaborative interaction, Evaluation, Mobile phones, Public interfaces, Social context
Source: Scopus
Source ID: 84855410287

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

A survey on aims and environments of diversification and obfuscation in software security

Diversification and obfuscation methods are promising approaches used tosecuresoftware and prevent malware from functioning. Diversification makes each software instance unique so that malware attacks cannot rely on the knowledge of the program's execution environment and/or internal structure anymore. We present a systematic literature review on the state of-the-art of diversification and obfuscation research aiming to improve software security between 1993 and 2014. As the result of systematic search, in the final phase, 209 related papers were included in this study. In this study we focus on two specific research questions: what are the aims of diversification and obfuscation techniques and what are the environments they are applied to. The former question includes the languages and the execution environments that can benefit from these two techniques, while the second question presents the goals of the techniques and also the type of attacks they mitigate. is held by the owner/author(s). Publication rights licensed to ACM.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Turun Yliopisto/Turun Biomateriaalikeskus
Contributors: Hosseinzadeh, S., Rauti, S., Laurén, S., Mäkelä, J. M., Holvitie, J., Hyrynsalmi, S., Leppänen, V.
Number of pages: 8
Pages: 113-120
Publication date: 23 Jun 2016

Host publication information

Title of host publication: Computer Systems and Technologies 17th International Conference, CompSysTech 2016 - Proceedings
Volume: 1164
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450341820
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Diversification, Obfuscation, Software security, Systematic literature review (SLR)
Source: Scopus
Source ID: 85000983786

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

Similarity induced group sparsity for non-negative matrix factorisation

Non-negative matrix factorisations are used in several branches of signal processing and data analysis for separation and classification. Sparsity constraints are commonly set on the model to promote discovery of a small number of dominant patterns. In group sparse models, atoms considered to belong to a consistent group are permitted to activate together, while activations across groups are suppressed, reducing the number of simultaneously active sources or other structures. Whereas most group sparse models require explicit division of atoms into separate groups without addressing their mutual relations, we propose a constraint that permits dynamic relationships between atoms or groups, based on any defined distance measure. The resulting solutions promote approximation with components considered similar to each other. Evaluation results are shown for speech enhancement and noise robust speech and speaker recognition.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Audio research group, Signal Processing Research Community (SPRC), Aalto University
Contributors: Hurmalainen, A., Saeidi, R., Virtanen, T.
Number of pages: 5
Pages: 4425-4429
Publication date: 4 Aug 2015

Host publication information

Title of host publication: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
ISBN (Print): 9781467369978
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: group sparsity, non-negative matrix factorization, sparse representations, speaker recognition, speech recognition
Source: Scopus
Source ID: 84946089342

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

Model selection for linear classifiers using Bayesian error estimation

Regularized linear models are important classification methods for high dimensional problems, where regularized linear classifiers are often preferred due to their ability to avoid overfitting. The degree of freedom of the model dis determined by a regularization parameter, which is typically selected using counting based approaches, such as K-fold cross-validation. For large data, this can be very time consuming, and, for small sample sizes, the accuracy of the model selection is limited by the large variance of CV error estimates. In this paper, we study the applicability of a recently proposed Bayesian error estimator for the selection of the best model along the regularization path. We also propose an extension of the estimator that allows model selection in multiclass cases and study its efficiency with L-1 regularized logistic regression and L-2 regularized linear support vector machine. The model selection by the new Bayesian error estimator is experimentally shown to improve the classification accuracy, especially in small sample-size situations, and is able to avoid the excess variability inherent to traditional cross-validation approaches. Moreover, the method has significantly smaller computational complexity than cross-validation. (C) 2015 Elsevier Ltd. All rights reserved.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Vision, Research Community on Data-to-Decision (D2D), Universidad Carlos III de Madrid
Contributors: Huttunen, H., Tohka, J.
Number of pages: 10
Pages: 3739-3748
Publication date: Nov 2015
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition
Volume: 48
Issue number: 11
ISSN (Print): 0031-3203
Ratings: 
  • Scopus rating (2015): CiteScore 8.6 SJR 1.579 SNIP 2.996
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Logistic regression, Support vector machine, Regularization, Bayesian error estimator, Linear classifier, MULTINOMIAL LOGISTIC-REGRESSION, SUPPORT VECTOR MACHINES, CLASSIFICATION, PERFORMANCE, BOUNDS

Bibliographical note

EXT="Tohka, Jussi"

Source: Scopus
Source ID: 84937812363

Research output: Contribution to journalArticleScientificpeer-review

The influence of developer multi-homing on competition between software ecosystems

Having a large number of applications in the marketplace is considered a critical success factor for software ecosystems. The number of applications has been claimed to determine which ecosystems holds the greatest competitive advantage and will eventually dominate the market. This paper investigates the influence of developer multi-homing (i.e., participating in more than one ecosystem) in three leading mobile application ecosystems. Our results show that when regarded as a whole, mobile application ecosystems are single-homing markets. The results further show that 3% of all developers generate more than 80% of installed applications and that multi-homing is common among these developers. Finally, we demonstrate that the most installed content actually comprises only a small number of the potential value propositions. The results thus imply that attracting and maintaining developers of superstar applications is more critical for the survival of a mobile application ecosystem than the overall number of developers and applications. Hence, the mobile ecosystem is unlikely to become a monopoly. Since exclusive contracts between application developers and mobile application ecosystems are rare, multi-homing is a viable component of risk management and a publishing strategy. The study advances the theoretical understanding of the influence of multi-homing on competition in software ecosystems.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Information Technology, University of Turku, VTT Technical Research Centre of Finland
Contributors: Hyrynsalmi, S., Suominen, A., Mäntymäki, M.
Number of pages: 9
Pages: 119-127
Publication date: 1 Jan 2016
Peer-reviewed: Yes

Publication information

Journal: Journal of Systems and Software
Volume: 111
ISSN (Print): 0164-1212
Ratings: 
  • Scopus rating (2016): CiteScore 5.3 SJR 0.617 SNIP 2.139
Original language: English
ASJC Scopus subject areas: Hardware and Architecture, Software, Information Systems
Keywords: Multi-homing, Software ecosystem, Two-sided markets
Source: Scopus
Source ID: 84949783538

Research output: Contribution to journalArticleScientificpeer-review

Full-reference metrics multidistortional analysis

This paper is devoted to analysis and further improvement of full-reference metrics of image visual quality. The effectiveness of a metric is characterized by the rank correlation factors between the obtained array of mean opinion scores (MOS) and the corresponding array of given metric values. This allows to determine the correspondence of a considered metric to a human visual system (HVS). Results obtained on the database TID2013 show that Spearman correlation for the best existing metrics (PSNRHMA, FSIM, SFF, etc.) does not exceed 0.85. In this paper, extended verification tools that allow to detect the shortcomings of the metrics taking into account combined distortions is proposed. An example for further improvement of the PSNRHMA metric is presented.

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.
Number of pages: 9
Pages: 27-35
Publication date: 2017

Host publication information

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

Publication series

Name: Electronic Imaging
ISSN (Print): 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
Keywords: Full-reference metrics, Image visual quality assessment, Metrics analysis, Metrics verification, Multiple distortions

Bibliographical note

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

Source: Scopus
Source ID: 85040625876

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

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

How to study programming on mobile touch devices - Interactive Python code exercises

Scaffolded learning tasks where programs are constructed from predefined code fragments by dragging and dropping them (i.e. Parsons problems) are well suited to mobile touch devices, but quite limited in their applicability. They do not adequately cater for different approaches to constructing a program. After studying solutions to automatically assessed programming exercises, we found out that many different solutions are composed of a relatively small set of mutually similar code lines. Thus, they can be constructed by using the drag-and-drop approach if only it was possible to edit some small parts of the predefined fragments. Based on this, we have designed and implemented a new exercise type for mobile devices that builds on Parsons problems and falls somewhere between their strict scaffolding and full-blown coding exercises. In these exercises, we can gradually fade the scaffolding and allow programs to be constructed more freely so as not to restrict thinking and limit creativity too much while still making sure we are able to deploy them to small-screen mobile devices. In addition to the new concept and the related implementation, we discuss other possibilities of how programming could be practiced on mobile devices.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Regulation of learning and active learning methods (REALMEE), Department of Computer Science and Eng., Aalto University
Contributors: Ihantola, P., Helminen, J., Karavirta, V.
Number of pages: 8
Pages: 51-58
Publication date: 2013

Host publication information

Title of host publication: Proceedings - 13th Koli Calling International Conference on Computing Education Research, Koli Calling 2013
ISBN (Print): 9781450324823
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: learning, mLearning, mobile learning, mobile touch devices, parsons problem, parsons puzzle, programming, Python, teaching
Source: Scopus
Source ID: 84889570829

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

Head movement and facial expressions as game input

This study aimed to develop and test a hands-free video game that utilizes information on the player's real-time face position and facial expressions as intrinsic elements of a gameplay. Special focus was given to investigating the user's subjective experiences in utilizing computer vision input in the game interaction. The player's goal was to steer a drunken character home as quickly as possible by moving their head. Additionally, the player could influence the behavior of game characters by using the facial expressions of frowning and smiling. The participants played the game with computer vision and a conventional joystick and rated the functionality of the control methods and their emotional and game experiences. The results showed that although the functionality of the joystick steering was rated higher than that of the computer vision method, the use of head movements and facial expressions enhanced the experiences of game playing in many ways. The participants rated playing with the computer vision technique as more entertaining, interesting, challenging, immersive, and arousing than doing so with a joystick. The results suggested that a high level of experienced arousal in the case of computer vision-based interaction may be a key factor for better experiences of game playing.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Augmented Human Activities (AHA)
Contributors: Ilves, M., Gizatdinova, Y., Surakka, V., Vankka, E.
Number of pages: 10
Pages: 147-156
Publication date: 2014
Peer-reviewed: Yes

Publication information

Journal: Entertainment Computing
Volume: 5
Issue number: 3
ISSN (Print): 1875-9521
Ratings: 
  • Scopus rating (2014): CiteScore 2.2 SJR 0.404 SNIP 1.424
Original language: English
ASJC Scopus subject areas: Software, Human-Computer Interaction
Keywords: Camera-based video game, Computer vision, Emotion, Face detection and tracking, Facial expression classification, Gameplay experience
Source: Scopus
Source ID: 84901983211

Research output: Contribution to journalArticleScientificpeer-review

Dynamic software updating techniques in practice and Educator's guides: A review

Patching a program during its execution without restarting is called dynamic software updating (DSU). DSU is well acknowledged in research, but rarely applied in practice as witnessed by constant need for reboots and restarts of both applications as well as operating systems. This raises the question of how well DSU related techniques are supported in education. In this paper, we review how the major software engineering and education guides acknowledge dynamic software updating techniques. Our analysis indicates that although DSU is not explicitly mentioned in the guides, the need is already well motivated and many DSU concepts are implicitly supported. Based on this, we argue that DSU could be introduced as an optional topic in software engineering studies.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: Software engineering
Contributors: Ilvonen, V., Ihantola, P., Mikkonen, T.
Number of pages: 5
Pages: 86-90
Publication date: 19 May 2016

Host publication information

Title of host publication: 2016 IEEE 29th International Conference on Software Engineering Education and Training (CSEET)
Publisher: IEEE
ISBN (Print): 978-1-5090-0765-3
ASJC Scopus subject areas: Software, Education
Keywords: Dynamic software updating, SEEK, Software engineering body of knowledge, Software engineering education knowledge, SWEBOK

Bibliographical note

JUFOID=67349

Source: Scopus
Source ID: 84974628254

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

Graph Embedded Extreme Learning Machine

In this paper, we propose a novel extension of the extreme learning machine (ELM) algorithm for single-hidden layer feedforward neural network training that is able to incorporate subspace learning (SL) criteria on the optimization process followed for the calculation of the network's output weights. The proposed graph embedded ELM (GEELM) algorithm is able to naturally exploit both intrinsic and penalty SL criteria that have been (or will be) designed under the graph embedding framework. In addition, we extend the proposed GEELM algorithm in order to be able to exploit SL criteria in arbitrary (even infinite) dimensional ELM spaces. We evaluate the proposed approach on eight standard classification problems and nine publicly available datasets designed for three problems related to human behavior analysis, i.e., the recognition of human face, facial expression, and activity. Experimental results denote the effectiveness of the proposed approach, since it outperforms other ELM-based classification schemes in all the cases.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Pages: 311 - 324
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Cybernetics
Volume: 46
Issue number: 1
ISSN (Print): 2168-2267
Ratings: 
  • Scopus rating (2016): CiteScore 12 SJR 2.927 SNIP 3.301
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Human-Computer Interaction, Information Systems, Software, Control and Systems Engineering, Electrical and Electronic Engineering

Research output: Contribution to journalArticleScientificpeer-review

On the kernel Extreme Learning Machine classifier

In this paper, we discuss the connection of the kernel versions of the ELM classifier with infinite Single-hidden Layer Feedforward Neural networks and show that the original ELM kernel definition can be adopted for the calculation of the ELM kernel matrix for two of the most common activation functions, i.e., the RBF and the sigmoid functions. In addition, we show that a low-rank decomposition of the kernel matrix defined on the input training data can be exploited in order to determine an appropriate ELM space for input data mapping. The ELM space determined from this process can be subsequently used for network training using the original ELM formulation. Experimental results denote that the adoption of the low-rank decomposition-based ELM space determination leads to enhanced performance, when compared to the standard choice, i.e., random input weights generation.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 7
Pages: 11-17
Publication date: 1 Mar 2015
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 54
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2015): CiteScore 5.1 SJR 0.95 SNIP 2.002
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Extreme learning machine, Infinite networks, Single-hidden layer networks
Source: Scopus
Source ID: 84920068822

Research output: Contribution to journalArticleScientificpeer-review

The MOBISERV-AIIA eating and drinking multi-view database for vision-based assisted living

Assisted living has a particular social importance in most developed societies, due to the increased life expectancy of the general population and the ensuing ageing problems. It has also importance for the provision of improved home care in cases of disabled persons or persons suffering from certain diseases that have high social impact. In this context, the development of computer vision systems capable to identify human eating and drinking activity can be really useful in order to prevent undernourishment/malnutrition and dehydration in a smart home environment targeting to extend independent living of older persons in the early stage of dementia. In this paper, we first describe the human centered interface specifications and implementations for such a system, which can be supported by ambient intelligence and robotic technologies. We, subsequently, describe a multi-view eating and drinking activity recognition database that has been created in order to facilitate research towards this direction. The database has been created by using four cameras in order to produce multi-view videos, each depicting one of twelve persons having a meal, resulting to a database size equal to 59.68 hours in total. Various types of meals have been recorded, i.e., breakfast, lunch and fast food. Moreover, the persons have different sizes, clothing and are of different sex. The database has been annotated in a frame base in terms of person ID and activity class. We hope that such a database will serve as a benchmark data set for computer vision researchers in order to devise methods targeting to this important application.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), School of Dentistry, Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Marami, E., Tefas, A., Pitas, I., Lyroudia, K.
Number of pages: 20
Pages: 254-273
Publication date: 1 Mar 2015
Peer-reviewed: Yes

Publication information

Journal: Journal of Information Hiding and Multimedia Signal Processing
Volume: 6
Issue number: 2
ISSN (Print): 2073-4212
Ratings: 
  • Scopus rating (2015): CiteScore 2.6 SJR 0.414 SNIP 1.483
Original language: English
ASJC Scopus subject areas: Computer Vision and Pattern Recognition, Software
Keywords: Activity recognition, Multiview video database, Nutrition assistance, Smart home environment
Source: Scopus
Source ID: 84911457722

Research output: Contribution to journalArticleScientificpeer-review

Kernel reference discriminant analysis

Linear Discriminant Analysis (LDA) and its nonlinear version Kernel Discriminant Analysis (KDA) are well-known and widely used techniques for supervised feature extraction and dimensionality reduction. They determine an optimal discriminant space for (non)linear data projection based on certain assumptions, e.g. on using normal distributions (either on the input or in the kernel space) for each class and employing class representation by the corresponding class mean vectors. However, there might be other vectors that can be used for classes representation, in order to increase class discrimination in the resulted feature space. In this paper, we propose an optimization scheme aiming at the optimal class representation, in terms of Fisher ratio maximization, for nonlinear data projection. Compared to the standard approach, the proposed optimization scheme increases class discrimination in the reduced-dimensionality feature space and achieves higher classification rates in publicly available data sets.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 7
Pages: 85-91
Publication date: 1 Nov 2014
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 49
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2014): CiteScore 4.3 SJR 0.73 SNIP 2.131
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Kernel Discriminant Analysis, Kernel Spectral Regression, Optimized class representation
Source: Scopus
Source ID: 84904957982

Research output: Contribution to journalArticleScientificpeer-review

Discriminant Bag of Words based representation for human action recognition

In this paper we propose a novel framework for human action recognition based on Bag of Words (BoWs) action representation, that unifies discriminative codebook generation and discriminant subspace learning. The proposed framework is able to, naturally, incorporate several (linear or non-linear) discrimination criteria for discriminant BoWs-based action representation. An iterative optimization scheme is proposed for sequential discriminant BoWs-based action representation and codebook adaptation based on action discrimination in a reduced dimensionality feature space where action classes are better discriminated. Experiments on five publicly available data sets aiming at different application scenarios demonstrate that the proposed unified approach increases the codebook discriminative ability providing enhanced action classification performance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 8
Pages: 185-192
Publication date: 1 Nov 2014
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 49
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2014): CiteScore 4.3 SJR 0.73 SNIP 2.131
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Bag of Words, Codebook learning, Discriminant learning
Source: Scopus
Source ID: 84907347636

Research output: Contribution to journalArticleScientificpeer-review

Minimum Variance Extreme Learning Machine for human action recognition

In this paper we propose an algorithm for Single-hidden Layer Feedforward Neural networks training. Based on the observation that the learning process of such networks can be considered to be a non-linear mapping of the training data to a high-dimensional feature space, followed by a data projection process to a low-dimensional space where classification is performed by a linear classifier, we extend the Extreme Learning Machine (ELM) algorithm in order to exploit the training data dispersion in its optimization process. The proposed Minimum Variance Extreme Learning Machine classifier is evaluated in human action recognition, where we compare its performance with that of other ELM-based classifiers, as well as the kernel Support Vector Machine classifier.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 5
Pages: 5427-5431
Publication date: 2014

Host publication information

Title of host publication: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
Article number: 6854640
ISBN (Print): 9781479928927
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: Classification, Extreme Learning Machine, Human Action Recognition, Single-hidden Layer Feedforward Neural networks
Source: Scopus
Source ID: 84905233232

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

Multi-view action recognition based on action volumes, fuzzy distances and cluster discriminant analysis

In this paper, we present a view-independent action recognition method exploiting a low computational-cost volumetric action representation. Binary images depicting the human body during action execution are accumulated in order to produce the so-called action volumes. A novel time-invariant action representation is obtained by exploiting the circular shift invariance property of the magnitudes of the Discrete Fourier Transform coefficients. The similarity of an action volume with representative action volumes is exploited in order to map it to a lower-dimensional feature space that preserves the action class properties. Discriminant learning is, subsequently, employed for further dimensionality reduction and action class discrimination. By using such an action representation, the proposed approach performs fast action recognition. By combining action recognition results coming from different view angles, high recognition rates are obtained. The proposed method is extended to interaction recognition, i.e., to human action recognition involving two persons. The proposed approach is evaluated on a publicly available action recognition database using experimental settings simulating situations that may appear in real-life applications, as well as on a new nutrition support action recognition database.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 13
Pages: 1445-1457
Publication date: Jun 2013
Peer-reviewed: Yes

Publication information

Journal: Signal Processing
Volume: 93
Issue number: 6
ISSN (Print): 0165-1684
Ratings: 
  • Scopus rating (2013): CiteScore 5.1 SJR 0.909 SNIP 2.244
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Software, Signal Processing, Computer Vision and Pattern Recognition
Keywords: Action recognition, Action volumes, Cluster discriminant analysis, Fuzzy vector quantization
Source: Scopus
Source ID: 84875267100

Research output: Contribution to journalArticleScientificpeer-review

On the optimal class representation in linear discriminant analysis

Linear discriminant analysis (LDA) is a widely used technique for supervised feature extraction and dimensionality reduction. LDA determines an optimal discriminant space for linear data projection based on certain assumptions, e.g., on using normal distributions for each class and employing class representation by the mean class vectors. However, there might be other vectors that can represent each class, to increase class discrimination. In this brief, we propose an optimization scheme aiming at the optimal class representation, in terms of Fisher ratio maximization, for LDA-based data projection. Compared with the standard LDA approach, the proposed optimization scheme increases class discrimination in the reduced dimensionality space and achieves higher classification rates in publicly available data sets.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 7
Pages: 1491-1497
Publication date: 2013
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Neural Networks and Learning Systems
Volume: 24
Issue number: 9
ISSN (Print): 2162-237X
Ratings: 
  • Scopus rating (2013): CiteScore 9.4 SJR 2.33 SNIP 3.576
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Computer Networks and Communications, Computer Science Applications, Software
Keywords: Class representation, data projection, linear discriminant analysis (LDA), subspace learning
Source: Scopus
Source ID: 84882899597

Research output: Contribution to journalArticleScientificpeer-review

Dynamic action recognition based on dynemes and Extreme Learning Machine

In this paper, we propose a novel method that performs dynamic action classification by exploiting the effectiveness of the Extreme Learning Machine (ELM) algorithm for single hidden layer feedforward neural networks training. It involves data grouping and ELM based data projection in multiple levels. Given a test action instance, a neural network is trained by using labeled action instances forming the groups that reside to the test sample's neighborhood. The action instances involved in this procedure are, subsequently, mapped to a new feature space, determined by the trained network outputs. This procedure is performed multiple times, which are determined by the test action instance at hand, until only a single class is retained. Experimental results denote the effectiveness of the dynamic classification approach, compared to the static one, as well as the effectiveness of the ELM in the proposed dynamic classification setting.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 9
Pages: 1890-1898
Publication date: 2013
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 34
Issue number: 15
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2013): CiteScore 4.8 SJR 0.768 SNIP 2.474
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Activity recognition, Dynamic classification, Extreme Learning Machine, Fuzzy vector quantization
Source: Scopus
Source ID: 84885069818

Research output: Contribution to journalArticleScientificpeer-review

Sparse extreme learning machine classifier exploiting intrinsic graphs

This paper presents an analysis of the recently proposed sparse extreme learning machine (S-ELM) classifier and describes an optimization scheme that can be used to calculate the network output weights. This optimization scheme exploits intrinsic graph structures in order to describe geometric data relationships in the so-called ELM space. Kernel formulations of the approach operating in ELM spaces of arbitrary dimensions are also provided. It is shown that the application of the optimization scheme exploiting geometric data relationships in the original ELM space is equivalent to the application of the original S-ELM to a transformed ELM space. The experimental results show that the incorporation of geometric data relationships in S-ELM can lead to enhanced performance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki, Department of Informatics, Aristotle University of Thessaloniki
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 5
Pages: 192-196
Publication date: 1 Nov 2015
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition Letters
Volume: 65
ISSN (Print): 0167-8655
Ratings: 
  • Scopus rating (2015): CiteScore 5.1 SJR 0.95 SNIP 2.002
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Intrinsic graphs, Single-hidden layer neural networks, Sparse extreme learning machine
Source: Scopus
Source ID: 84940388000

Research output: Contribution to journalArticleScientificpeer-review

Enhancing class discrimination in Kernel Discriminant Analysis

In this paper, we propose an optimization scheme aiming at optimal nonlinear data projection, in terms of Fisher ratio maximization. To this end, we formulate an iterative optimization scheme consisting of two processing steps: optimal data projection calculation and optimal class representation determination. Compared to the standard approach employing the class mean vectors for class representation, the proposed optimization scheme increases class discrimination in the reduced-dimensionality feature space. We evaluate the proposed method in standard classification problems, as well as on the classification of human actions and face, and show that it is able to achieve better generalization performance, when compared to the standard approach.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research Community on Data-to-Decision (D2D), Aristotle University of Thessaloniki
Contributors: Iosifidis, A., Tefas, A., Pitas, I.
Number of pages: 5
Pages: 1926-1930
Publication date: 4 Aug 2015

Host publication information

Title of host publication: ICASSP, IEEE International Conference on Acoustics, Speech and Signal Processing - Proceedings
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
Article number: 7178306
ISBN (Print): 9781467369978
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: Kernel Discriminant Analysis, Nonlinear data projection, Optimized Class Representation
Source: Scopus
Source ID: 84946088724

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

Nyström-based approximate kernel subspace learning

In this paper, we describe a method for the determination of a subspace of the feature space in kernel methods, which is suited to large-scale learning problems. Linear model learning in the obtained space corresponds to a nonlinear model learning process in the input space. Since the obtained feature space is determined only by exploiting properties of the training data, this approach can be used for generic nonlinear pattern recognition. That is, nonlinear data mapping can be considered to be a pre-processing step exploiting nonlinear relationships between the training data. Linear techniques can be subsequently applied in the new feature space and, thus, they can model nonlinear properties of the problem at hand. In order to appropriately address the inherent problem of kernel learning methods related to their time and memory complexities, we follow an approximate learning approach. We show that the method can lead to considerable operation speed gains and achieve very good performance. Experimental results verify our analysis.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Video, Research Community on Data-to-Decision (D2D)
Contributors: Iosifidis, A., Gabbouj, M.
Number of pages: 8
Pages: 190-197
Publication date: Sep 2016
Peer-reviewed: Yes

Publication information

Journal: Pattern Recognition
ISSN (Print): 0031-3203
Ratings: 
  • Scopus rating (2016): CiteScore 9 SJR 1.501 SNIP 3.005
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Vision and Pattern Recognition, Signal Processing
Keywords: Kernel methods, Nonlinear pattern recognition, Nonlinear projection trick, Nyström approximation
Source: Scopus
Source ID: 85013223573

Research output: Contribution to journalArticleScientificpeer-review

Supervised subspace learning based on deep randomized networks

In this paper, we propose a supervised subspace learning method that exploits the rich representation power of deep feedforward networks. In order to derive a fast, yet efficient, learning scheme we employ deep randomized neural networks that have been recently shown to provide good compromise between training speed and performance. For optimally determining the learnt subspace, we formulate a regression problem where we employ target vectors designed to encode both the labeling information available for the training data and geometric properties of the training data, when represented in the feature space determined by the network's last hidden layer outputs. We experimentally show that the proposed approach is able to outperform deep randomized neural networks trained by using the standard network target vectors.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Signal Processing, Research group: Video
Contributors: Iosifidis, A., Gabbouj, M.
Number of pages: 5
Pages: 2584-2588
Publication date: 18 May 2016

Host publication information

Title of host publication: 2016 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP)
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
ISBN (Print): 9781479999880
ASJC Scopus subject areas: Signal Processing, Software, Electrical and Electronic Engineering
Keywords: Deep Neural Networks, Network targets calculation, Supervised Subspace Learning
Source: Scopus
Source ID: 84973351642

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

One-Class Classification based on Extreme Learning and Geometric Class Information

In this paper, we propose an extreme learning machine (ELM)-based one-class classification method that exploits geometric class information. We formulate the proposed method to exploit data representations in the feature space determined by the network hidden layer outputs, as well as in ELM spaces of arbitrary dimensions. We show that the exploitation of geometric class information enhances performance. We evaluate the proposed approach in publicly available datasets and compare its performance with the recently proposed one-class extreme learning machine algorithm, as well as with standard and recently proposed one-class classifiers. Experimental results show that the proposed method consistently outperforms the remaining approaches.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Aristotle University of Thessaloniki, Aristotle University of Thessaloniki, Department of Informatics
Contributors: Iosifidis, A., Mygdalis, V., Tefas, A., Pitas, I.
Number of pages: 16
Pages: 1-16
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Neural Processing Letters
ISSN (Print): 1370-4621
Ratings: 
  • Scopus rating (2016): CiteScore 2.6 SJR 0.399 SNIP 0.777
Original language: English
ASJC Scopus subject areas: Software, Neuroscience(all), Computer Networks and Communications, Artificial Intelligence
Keywords: Big data, Extreme learning machine, Novelty detection, One-class classification

Bibliographical note

EXT="Tefas, Anastasios"

Source: Scopus
Source ID: 84982810055

Research output: Contribution to journalArticleScientificpeer-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

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

Gravity gradient routing for information delivery in fog Wireless Sensor Networks

Fog Computing is a new paradigm that has been proposed by CISCO to take full advantage of the ever growing computational capacity of the near-user or edge devices (e.g., wireless gateways and sensors). The paradigm proposes an architecture that enables the devices to host functionality of various user-centric services. While the prospects of Fog Computing promise numerous advantages, development of Fog Services remains under-investigated. This article considers an opportunity of Fog implementation for Alert Services on top of Wireless Sensor Network (WSN) technology. In particular, we focus on targeted WSN-alert delivery based on spontaneous interaction between a WSN and hand-held devices of its users. For the alert delivery, we propose a Gravity Routing concept that prioritizes the areas of high user-presence within the network. Based on the concept, we develop a routing protocol, namely the Gradient Gravity Routing (GGR) that combines targeted delivery and resilience to potential sensor-load heterogeneity within the network. The protocol has been compared against a set of state-of-the-art solutions via a series of simulations. The evaluation has shown the ability of GGR to match the performance of the compared solutions in terms of alert delivery ratio, while minimizing the overall energy consumption of the network.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno
Contributors: Ivanov, S., Balasubramaniam, S., Botvich, D., Akan, O. B.
Pages: 61-74
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Ad Hoc Networks
Volume: 46
ISSN (Print): 1570-8705
Ratings: 
  • Scopus rating (2016): CiteScore 6.1 SJR 0.648 SNIP 2.045
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Hardware and Architecture, Software
Keywords: Fog Computing, User-awareness, Wireless sensor networks
Source: Scopus
Source ID: 84964329276

Research output: Contribution to journalArticleScientificpeer-review

On delay distribution in IEEE 802.11 wireless networks

IEEE 802.11 wireless networks have received much attention over the past number of years. Still certain aspects of behavior of wireless networks have not been studied well enough. For example, understanding MAC layer packet delay distribution remains challenging yet. However, obtaining such distribution is highly beneficial for modeling QoS provided by wireless networks. This paper proposes a way of obtaining MAC delay distribution in case of single-hop networks. The proposed way is based on theory of terminating renewal processes and delivers approximation of good precision.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Wireless Communications and Positioning (WICO), Waterford Institute of Technology, Telecommunications Software and Systems Group (TSSG)
Contributors: Ivanov, S., Botvich, D., Balasubramaniam, S.
Number of pages: 3
Pages: 254-256
Publication date: 2011

Host publication information

Title of host publication: 16th IEEE Symposium on Computers and Communications, ISCC'11
Article number: 5983849
ISBN (Print): 9781457706783
ASJC Scopus subject areas: Software, Signal Processing, Mathematics(all), Computer Science Applications, Computer Networks and Communications
Keywords: delay distribution, IEEE 802.11, MAC layer, modeling
Source: Scopus
Source ID: 80052734083

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

Opportunities and Challenges of Mobile Applications as "Tickets-to-Talk": A Scenario-Based User Study

This paper presents a scenario-based user study of mobile application concepts that would encourage interaction between people within close proximity. The scenarios demonstrate three themes of digital tickets-to-talk: informing who and what are around, augmenting self-expression, and online interaction encouraging physical interaction. Our interview study explored the opportunities and challenges of such applications in developing into further face-to-face interactions between strangers. Tickets that are related to activities that convey a solid intention that would lead to practical collaboration, such as playing sports or studying together, have the best potential to advance to meaningful face-to-face interaction. Augmenting selfexpression and online interaction encouraging physical interaction were found to have potential to create curiosity but seen less credible by our 42 interview participants to motivate face-to-face interaction between strangers. We conclude by discussing the potential of each theme of ticket-to-talk based on our findings as well as related literature.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Augmented Human Activities (AHA)
Contributors: Jarusriboonchai, P., Olsson, T., Ojala, J., Väänänen-Vainio-Mattila, K.
Number of pages: 9
Pages: 89-97
Publication date: 2014

Host publication information

Title of host publication: Proceedings of the 13th International Conference on Mobile and Ubiquitous Multimedia, MUM2014, November 25-28, 2014, Melbourne, Australia
Place of publication: New York, NY
Publisher: ACM
ISBN (Print): 978-1-4503-3304-7

Publication series

Name: International conference on mobile and ubiquitous multimedia
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: Awareness system, Co-located interaction, Faceto-face interaction, Mobile technology, Scenarios, Storyboards, User experience, User study

Bibliographical note

Contribution: organisation=tie,FACT1=1<br/>Portfolio EDEND: 2014-12-31<br/>Publisher name: ACM

Source: researchoutputwizard
Source ID: 575

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

Increasing collocated people's awareness of the mobile user's activities: A field trial of social displays

Many activities that have traditionally been performed with different dedicated physical artifacts are now done with personal mobile devices. Consequently, the privacy of mobile interfaces has hampered social observability and chances for serendipitous interactions. For example, reading an electronic newspaper with a mobile device does not allow the surrounding people to be similarly aware of the reader's activity as traditional newspapers. Social displays are additional displays on mobile devices providing the surrounding people with light-weight cues about the activities of the device user. We implemented a prototype that reveals the user's current active application and presents its name on an e-ink display on the backside of a mobile device. We conducted a ten-day field trial with 13 participants using the prototype. The results show that the prototype was able to increase awareness of users' mobile activities and occasionally triggered interactions with others, without significantly violating the sense of privacy.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience
Contributors: Jarusriboonchai, P., Malapaschas, A., Olsson, T., Väänänen, K.
Number of pages: 12
Pages: 1691-1702
Publication date: 27 Feb 2016

Host publication information

Title of host publication: CSCW '16 - Proceedings of the 19th ACM Conference on Computer-Supported Cooperative Work & Social Computing
Publisher: ACM
ISBN (Print): 9781450335928
ASJC Scopus subject areas: Software, Computer Networks and Communications, Human-Computer Interaction
Keywords: Activity awareness, Backside display, Collocated interaction, Face-to-face interaction, Field study, Personal interface, Social display, Social interaction, User trial

Bibliographical note

Kysytty rt-versiosta 8.9.2020 EJ

Source: Scopus
Source ID: 84963542098

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

Social display...We can see what you are doing on your mobile device

Mobile devices have become powerful in terms of computing and supporting various human activities. People have moved some of their activities that earlier have been done with dedicated artifacts to mobile devices. However, due to the rather private and personal interfaces of mobile devices, activities that earlier were easily observable by surrounding others have become private, decreasing the surroundings people's awareness of a mobile user's activity and thus the possibilities for serendipitous interactions. We developed a prototype called social display; it provides light-weight visual cues about mobile user's current activity with the device. The cues are displayed on a display attached to the backside of the user's mobile device. We present the concept, explain the design decisions and briefly report key findings from, first, a focus group study and, second, a field trial study.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience
Contributors: Jarusriboonchai, P., Malapaschas, A., Olsson, T., Väänänen, K.
Number of pages: 4
Pages: 53-56
Publication date: 27 Feb 2016

Host publication information

Title of host publication: CSCW '16 Proceedings of the 19th ACM Conference on Computer-Supported Cooperative Work & Social Computing
Publisher: ACM
ISBN (Print): 9781450339506
ASJC Scopus subject areas: Software, Computer Networks and Communications, Human-Computer Interaction
Keywords: Activity awareness, Backside display, Collocated interaction, Face-to-face interaction, Field study, Personal interface, Social display, Social interaction, User trial
Source: Scopus
Source ID: 84963574828

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

Mobile Journalist Toolkit: A field study on producing news articles with a mobile device

Today's handheld mobile devices with advanced multimedia capabilities and wireless broadband connectivity have emerged as potential new tools for journalists to produce news articles. It is envisioned that they could enable faster, more authentic, and more efficient news production, and many large news producing organizations, including Reuters and BBC, have recently been experimenting with them. In this paper, we present a field study on using mobile devices to produce news articles. During the study, a group of 19 M.A.-level journalism students used the Mobile Journalist Toolkit, a lightweight set of tools for mobile journalist work built around the Nokia N82 camera phone, to produce an online news blog. Our results indicate that while the mobile device cannot completely replace the traditional tools, for some types of journalist tasks they provide major benefits over the traditional tools, and are thus a useful addition to the journalist's toolbox.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Software Systems, Nokia
Contributors: Jokela, T., Väätäjä, H., Koponen, T.
Number of pages: 8
Pages: 45-52
Publication date: 2009

Host publication information

Title of host publication: MindTrek 2009 - 13th International Academic MindTrek Conference: Everyday Life in the Ubiquitous Era
ISBN (Print): 9781605586335
ASJC Scopus subject areas: Computer Science Applications, Human-Computer Interaction, Software
Keywords: Camera phones, Field study, Journalism, Mobile devices, Multimedia publishing
Source: Scopus
Source ID: 76749139559

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

Using elicitation studies to generate collocated interaction methods

Elicitation studies allow collecting interaction methods directly from end-users by presenting the users with the end effect of an operation and then asking them to perform the action that caused it. Applying elicitation studies in the domain of collocated interaction might enable designing more intuitive and natural group interaction methods. However, in the past elicitation studies have primarily been conducted with individual users - they have rarely been applied to groups. In this paper, we report our initial experiences in using the elicitation study methodology to generate interaction methods for groups of collocated users with wearable devices.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience, Nokia, Unit of Human-Centered Technology (IHTE)
Contributors: Jokela, T., Rezaei, P. P., Väänänen, K.
Number of pages: 5
Pages: 1129-1133
Publication date: 6 Sep 2016

Host publication information

Title of host publication: Proceedings of the 18th International Conference on Human-Computer Interaction with Mobile Devices and Services Adjunct, MobileHCI 2016
Publisher: ACM
ISBN (Electronic): 9781450344135
ASJC Scopus subject areas: Information Systems, Computer Networks and Communications, Human-Computer Interaction, Software
Keywords: Collocated interaction, Elicitation study, Guessability study, Multi-device user interfaces, Wearable devices
Source: Scopus
Source ID: 84991110295

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

Classification of iPSC colony images using hierarchical strategies with support vector machines

In this preliminary research we examine the suitability of hierarchical strategies of multi-class support vector machines for classification of induced pluripotent stem cell (iPSC) colony images. The iPSC technology gives incredible possibilities for safe and patient specific drug therapy without any ethical problems. However, growing of iPSCs is a sensitive process and abnormalities may occur during the growing process. These abnormalities need to be recognized and the problem returns to image classification. We have a collection of 80 iPSC colony images where each one of the images is prelabeled by an expert to class bad, good or semigood. We use intensity histograms as features for classification and we evaluate histograms from the whole image and the colony area only having two datasets. We perform two feature reduction procedures for both datasets. In classification we examine how different hierarchical constructions effect the classification. We perform thorough evaluation and the best accuracy was around 54% obtained with the linear kernel function. Between different hierarchical structures, in many cases there are no significant changes in results. As a result, intensity histograms are a good baseline for the classification of iPSC colony images but more sophisticated feature extraction and reduction methods together with other classification methods need to be researched in future.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Electronics and Communications Engineering, Research group: Computational Biophysics and Imaging Group, BioMediTech, Augmented Human Activities (AHA), Integrated Technologies for Tissue Engineering Research (ITTE), University of Tampere, Univ Tampere, University of Tampere, BioMediTech, BMT FM5
Contributors: Joutsijoki, H., Rasku, J., Haponen, M., Baldin, I., Gizatdinova, Y., Paci, M., Saarikoski, J., Varpa, K., Siirtola, H., Ávalos-Salguero, J., Iltanen, K., Laurikkala, J., Penttinen, K., Hyttinen, J., Aalto-Setälä, K., Juhola, M.
Number of pages: 7
Pages: 86-92
Publication date: 13 Jan 2015

Host publication information

Title of host publication: IEEE SSCI 2014 - 2014 IEEE Symposium Series on Computational Intelligence - CIDM 2014: 2014 IEEE Symposium on Computational Intelligence and Data Mining, Proceedings
Publisher: The Institute of Electrical and Electronics Engineers, Inc.
Article number: 7008152
ISBN (Print): 9781479945191
ASJC Scopus subject areas: Artificial Intelligence, Information Systems, Signal Processing, Software

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

Who is moving - User or device? Experienced quality of mobile 3D video in vehicles

'Viewing while commuting' is a typical use case for mobile video. However, experimental and behavioral influences of watching three-dimensional (3D) video in vibrating vehicles have not been widely researched. The goal of this study is 1) to explore the influence of video presentation modes (two-dimensional and stereoscopic 3D) on the quality of experience and 2) to understand the nature of the movement patterns that users perform to maintain an optimal viewing position while viewing videos on a mobile device in three commuting contexts and in a controlled laboratory environment. A hybrid method for quality evaluation was used for combining quantitative preference ratings, qualitative descriptions of quality, situational audio/video data-collection, and sensors. The high-quality and heterogeneous audiovisual stimuli were viewed on a mobile device equipped with a parallax barrier display. The results showed that the stereoscopic 3D (S3D) video presentation mode provided more satisfying quality of experience than the two-dimensional presentation mode in all studied contexts. To maintain an optimal viewing position in the vehicles, the users moved the device in their hands to the directions around the vertical and the horizontal axes in a leaned sitting position. This movement behavior was guided by the contexts but not by the quality, indicating the general importance of these results for mobile video viewing in vibrating vehicles.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience, Eindhoven University of Technology, Nokia
Contributors: Jumisko-Pyykkö, S., Markopoulos, P., Hannuksela, M. M.
Publication date: 16 Nov 2015

Host publication information

Title of host publication: ACE 2015 - 12th Advances in Computer Entertainment Technology Conference, Proceedings
Publisher: ACM
Article number: 13
ISBN (Electronic): 9781450338523
ASJC Scopus subject areas: Human-Computer Interaction, Computer Networks and Communications, Computer Vision and Pattern Recognition, Software
Keywords: 3D, Experienced quality, Mobile video, Movement, Perception, Quasi-experiments
Source: Scopus
Source ID: 84979759186

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

Temporal dimensions of affect in user experience of digital news in the field

This paper examines temporal dimensions of affective experiences as part of user experience of digital news reading in field conditions in two case studies. The first study focused on user experience of novel browser optimized versions of news for tablet computers. The second study examined the experience of digital replicas. The participants were active readers of newspapers studied. The daily reporting of affect was done over the usage period of one week. The results of both studies showed that there are differences between positive and negative affect, in their dynamism over time and individual differences they captured. The amount of negative emotions was very low with small individual differences and it reduced over time. In contrast, positive affect indicated slightly positive user experience with larger amount of individual differences. Its main dynamism was expressed at the beginning of study.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience, Eindhoven University of Technology
Contributors: Jumisko-Pyykkö, S., Pesonen, E., Väätäjä, H.
Pages: 192-197
Publication date: 17 Oct 2016

Host publication information

Title of host publication: AcademicMindtrek 2016 - Proceedings of the 20th International Academic Mindtrek Conference
Publisher: ACM
ISBN (Electronic): 9781450343671
ASJC Scopus subject areas: Human-Computer Interaction, Software, Computer Science Applications
Keywords: Authentication, Browser, Digital news, Digital replica, Emotion, Reading, Tablet, User experience
Source: Scopus
Source ID: 84994817765

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

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

The fuzzy front end of experience design

The basic idea behind Experience Design approach is that before ideating the solution, you define what experience to design for. This is a critical point in a design process, because the experience goal needs to be appropriate for the target context of use, in line with the brand experience, and meaningful to truly engage users. In the early phases of the experience design process, in the fuzzy front end, there are several sources that can guide experience goal setting. One important way is empathic understanding of the users' world and stepping into the users' shoes, but there are also other sources of insight and inspiration for setting the experiential goals such as brand promise, technology and societal trends as well as mere vision of renewal. In this workshop, we aim to collect examples of the fuzzy front end of the experience design process and analyze how the different sources of insight and inspiration influence experience goal setting. Copyright is held by the owner/author(s).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Department of Pervasive Computing, Research area: User experience, Augmented Human Activities (AHA), Aalto University, VTT Technical Research Centre of Finland, School of Arts, Design and Architecture
Contributors: Kaasinen, E., Väätäjä, H., Karvonen, H., Lu, Y.
Number of pages: 4
Pages: 797-800
Publication date: 26 Oct 2014

Host publication information

Title of host publication: Proceedings of the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational
Place of publication: New York, NY
Publisher: ACM
ISBN (Print): 978-1-4503-2542-4

Publication series

Name: Nordic conference on human-computer interaction
ASJC Scopus subject areas: Human-Computer Interaction, Software
Keywords: Experience design, User experience, UX goals

Bibliographical note

Contribution: organisation=tie,FACT1=1<br/>Portfolio EDEND: 2014-12-31<br/>Publisher name: ACM

Source: researchoutputwizard
Source ID: 632

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

Effects of haptic feedback on gaze based auto scrolling

Eye tracking enables automatic scrolling based on natural viewing behavior. We were interested in the effects of haptic feedback on gaze behavior and user experience. We conducted an experiment where haptic feedback was used to forewarn the reader that their gaze had entered an active scrolling area. Results show no statistical differences between conditions with or without haptic feedback on task time or gaze behavior. However, user experience varied a lot. Some participants were not able to associate the haptics and the scrolling. Those who understood the connection found the haptic feedback useful. Further research is required to find out a delay between the forewarning and the start of scrolling that is short enough to make the association but yet long enough to support the feeling of control and enjoyable user experience. Copyright is held by the owner/author(s).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), School of Management (JKK)
Contributors: Käki, K., Špakov, O., Majaranta, P., Kangas, J.
Number of pages: 4
Pages: 947-950
Publication date: 26 Oct 2014

Host publication information

Title of host publication: Proceedings of the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational
Publisher: Association for Computing Machinery, Inc
ISBN (Electronic): 1595930361, 9781450325424
ASJC Scopus subject areas: Human-Computer Interaction, Software
Keywords: Eye tracking, Gaze input, Haptics, Vibrotactile feedback
Source: Scopus
Source ID: 84911380351

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

Collaborative navigation in virtual worlds: How gender and game experience influence user behavior

There exists a large base of evidence for gender differences in human navigation. However, there is not much research on gender differences in collaborative aspects of navigation, including the interaction of individuals during collaborative wayfinding tasks in virtual environments. In light of this, we present a study of a collaborative virtual environment, Berlin Kompass. The goal of this study was to find out the main differences between genders in collaborative wayfinding. The application was evaluated in the context of foreign language learning in schools with over 200 students, where the users navigated through cityscapes while interacting verbally with each other. We collected and analyzed interaction logs, questionnaire data and audio and video recordings to gain insights into gender-related differences in wayfinding in virtual worlds. Our findings suggest that several differences that are evident in single user systems are not present when the collaborative aspect is added. Male users were more immersed during the task than females. One of the explaining factors for this might be video game experience. Genders also communicated differently - males spoke in longer utterances whereas females had more, shorter utterances. Males referred more to relative directions and dynamic landmarks such as cars and pedestrians while navigating. Males with more video game experience also provided more positive subjective user experience feedback on the application.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), University of Tampere
Contributors: Kallioniemi, P., Heimonen, T., Turunen, M., Hakulinen, J., Keskinen, T., Pihkala-Posti, L., Okkonen, J., Raisamo, R.
Number of pages: 10
Pages: 173-182
Publication date: 13 Nov 2015

Host publication information

Title of host publication: Proceedings - VRST 2015: 21st ACM Symposium on Virtual Reality Software and Technology
Volume: 13-15-November-2015
Publisher: Association for Computing Machinery
ISBN (Electronic): 9781450339902
ASJC Scopus subject areas: Software
Keywords: Gender differences, Virtual environments, Wayfinding
Source: Scopus
Source ID: 84980038945

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

Gaze gestures and haptic feedback in mobile devices

Anticipating the emergence of gaze tracking capable mobile devices, we are investigating the use of gaze as an input modality in handheld mobile devices. We conducted a study of combining gaze gestures with vibrotactile feedback. Gaze gestures were used as an input method in a mobile device and vibrotactile feedback as a new alternative way to give confirmation of interaction events. Our results show that vibrotactile feedback significantly improved the use of gaze gestures. The tasks were completed faster and rated easier and more comfortable when vibrotactile feedback was provided.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), School of Management (JKK)
Contributors: Kangas, J., Akkil, D., Rantala, J., Isokoski, P., Majaranta, P., Raisamo, R.
Number of pages: 4
Pages: 435-438
Publication date: 2014

Host publication information

Title of host publication: CHI 2014: One of a CHInd - Conference Proceedings, 32nd Annual ACM Conference on Human Factors in Computing Systems
Publisher: Association for Computing Machinery
ISBN (Print): 9781450324731
ASJC Scopus subject areas: Software, Human-Computer Interaction, Computer Graphics and Computer-Aided Design
Keywords: Gaze interaction, Gaze tracking, Haptic feedback
Source: Scopus
Source ID: 84900413921

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

Using gaze gestures with haptic feedback on glasses

Wearable computing devices are gradually becoming common, and head-mounted devices such as Google Glass are already available. These devices present new interaction challenges as the devices are usually small in size, and also the usage environment sets limitations on the available interaction modalities. One potential interaction method could be to use gaze for input and haptics for output with a head-worn device. We built a demonstration system to show how gaze gestures could be used to control a simple information application together with head area haptic feedback for gesture confirmation. The demonstration and experiences of early user studies have shown that users perceive such an input-output combination useful. Copyright is held by the owner/author(s).

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Augmented Human Activities (AHA), School of Management (JKK)
Contributors: Kangas, J., Akkil, D., Rantala, J., Isokoski, P., Majaranta, P., Raisamo, R.
Number of pages: 4
Pages: 1047-1050
Publication date: 26 Oct 2014

Host publication information

Title of host publication: Proceedings of the NordiCHI 2014: The 8th Nordic Conference on Human-Computer Interaction: Fun, Fast, Foundational
Publisher: Association for Computing Machinery, Inc
ISBN (Electronic): 1595930361, 9781450325424
ASJC Scopus subject areas: Human-Computer Interaction, Software
Keywords: Gaze gestures, Gaze input, Haptics, Vibrotactile feedback, Wearable computing
Source: Scopus
Source ID: 84911444165

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

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

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

Power harvesting from microwave oven electromagnetic leakage

In this paper, we considered the possibility of using electricity harvested from the microwave field leaked from commercial microwave ovens. Our experimental results showed that the leakage received by a dipole antenna was about 0 dBm (1 mW) at a point 5 cm in front of the door. A rectenna consisting of a dipole antenna and charge pump can convert the leaked microwave energy into a DC current. When a microwave oven is operated for 2 min, 9.98 mJ of energy was harvested. We demonstrated that this energy is sufficient for powering a digital cooking timer to count down for 3 min and beep for 2.5 s. The operation of other kitchen devices was also demonstrated.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Sensing Systems for Wireless Medicine (MediSense), Georgia Institute of Technology, University of Tokyo
Contributors: Kawahara, Y., Bian, X., Shigeta, R., Vyas, R., Tentzeris, M. M., Asami, T.
Number of pages: 9
Pages: 373-381
Publication date: 2013

Host publication information

Title of host publication: UbiComp 2013 - Proceedings of the 2013 ACM International Joint Conference on Pervasive and Ubiquitous Computing
ISBN (Print): 9781450317702
ASJC Scopus subject areas: Software
Keywords: Energy harvesting, Microwave oven, Wireless sensing
Source: Scopus
Source ID: 84885220237

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

SenSprout: Inkjet-printed soil moisture and leaf wetness sensor

In this paper we show a low cost and environmentally friendly fabrication for an agricultural sensing application. An antenna, a soil moisture sensor, and a leaf wetness sensor are inkjet-printed on paper substrate. A microprocessor attached to the paper substrate is capable of detecting the capacitance change on the surface of the sensor, and report the data over the wireless communication interface. This sensing system is useful to optimize irrigation systems.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Sensing Systems for Wireless Medicine (MediSense), University of Tokyo, Georgia Institute of Technology
Contributors: Kawahara, Y., Lee, H., Tentzeris, M. M.
Number of pages: 1
Pages: 545
Publication date: 2012

Host publication information

Title of host publication: UbiComp'12 - Proceedings of the 2012 ACM Conference on Ubiquitous Computing
ISBN (Print): 9781450312240
ASJC Scopus subject areas: Software
Keywords: Energy harvesting, Inkjet-printing
Source: Scopus
Source ID: 84879479986

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

Schoolchildren's user experiences on a physical exercise game utilizing lighting and audio

Motivated by the troubling news on decreased exercise amount and increased obesity among children and adolescents, we investigated the possibilities of interactive lighting technology in encouraging children to participate in physical exercise in schools. We have created a story-driven physical exercise game based on light and sound utilizing a reasonably priced technological setup. The game has been evaluated with several groups of schoolchildren during physical education classes. The results show that a physical exercise game enhanced with lighting and audio keeps schoolchildren motivated both mentally and physically even after several playtimes. In subjective evaluations, participants still found the story of the game interesting after three playtimes, and were eager to exercise this way again.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Augmented Human Activities (AHA), Mathematical modelling with wide societal impact (MathImpact), University of Tampere
Contributors: Keskinen, T., Hakulinen, J., Turunen, M., Heimonen, T., Sand, A., Paavilainen, J., Parviainen, J., Yrjänäinen, S., Mäyrä, F., Okkonen, J., Raisamo, R.
Number of pages: 10
Pages: 475-484
Publication date: 1 Dec 2014
Peer-reviewed: Yes

Publication information

Journal: Entertainment Computing
Volume: 5
Issue number: 4
ISSN (Print): 1875-9521
Ratings: 
  • Scopus rating (2014): CiteScore 2.2 SJR 0.404 SNIP 1.424
Original language: English
ASJC Scopus subject areas: Software, Human-Computer Interaction
Keywords: Exergaming, Interactive lighting, Physical education, Schoolchildren, Storytelling, User experience
Source: Scopus
Source ID: 84912526011

Research output: Contribution to journalArticleScientificpeer-review

SymbolChat: A flexible picture-based communication platform for users with intellectual disabilities

Persons with intellectual disabilities benefit from participating in the modern information society, especially the World Wide Web, social media and Internet-mediated communication services. Although several computer-based prototypes and commercial systems have been introduced for accessible in-person communication, currently few applications and services exist to support synchronous remote communication for this user group. We introduce SymbolChat, a software platform that supports the creation of multimodal communication applications utilizing picture-based instant messaging. End users and their support personnel can customize the input and output features of the application based on their individual needs and abilities. The interaction is based on touchscreen input and speech output using speech synthesis technology. The SymbolChat platform was developed together with the prospective end users and practitioners in the field of special needs care. We evaluated the prototype application in a field study with nine users with varying degrees of intellectual and other disabilities. The results clearly indicate that the participants were able to express themselves in spontaneous communication using a large-scale picture-based vocabulary (around 2000 symbols) even without prior training in the use of symbols. This finding was supported in the constructive feedback gathered from professionals working in the area. We also successfully applied methodology from other settings, such as child-computer interaction to evaluate interaction in this challenging context. Overall, the results show that social inclusion for people with intellectual disabilities can be improved with customizable communication tools. The implemented communication platform forms a solid basis for further improvements and new communication services. In addition, we found that users with motor impairments would greatly benefit from alternative input and output methods for symbol browsing and selection.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Augmented Human Activities (AHA), Laurea University of Applied Sciences
Contributors: Keskinen, T., Heimonen, T., Turunen, M., Rajaniemi, J. P., Kauppinen, S.
Number of pages: 13
Pages: 374-386
Publication date: Sep 2012
Peer-reviewed: Yes

Publication information

Journal: Interacting with Computers
Volume: 24
Issue number: 5
ISSN (Print): 0953-5438
Ratings: 
  • Scopus rating (2012): CiteScore 4.9 SJR 0.669 SNIP 1.982
Original language: English
ASJC Scopus subject areas: Human-Computer Interaction, Software
Keywords: Augmentative and alternative communication, Instant messaging, Picture-based communication, User-centered design
Source: Scopus
Source ID: 84866739334

Research output: Contribution to journalArticleScientificpeer-review

System level performance simulation of distributed GENESYS applications on multi-core platforms

Modern high end mobile devices employ multi-core platforms and support diverse distributed applications due to increased computational power. A brisk performance evaluation phase is required after the application modelling to evaluate feasibility of new distributed applications on the multi-core mobile platforms. GENESYS modelling methodology which employs service-oriented and component based distributed application design has been extended for this purpose such that application level services are refined to platform-level services allowing mapping of GENESYS application architecture to workload models used in performance evaluation. This results in easy extraction of application workload models, reducing the time and effort in the performance evaluation phase needed for architectural exploration. This article presents the way brisk performance evaluation of distributed GENESYS applications is achieved by employing extended GENESYS distributed application architecture. The approach is experimented with a case study. UML2.0 MARTE profile, Papyrus UML2.0 modelling tool and SystemC were used for modelling and simulation.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Research group: System-on-Chip for GNSS, Wireless Communications and Cyber-Physical Embedded Computing, Department of Computer Systems, Wireless Communications and Positioning (WICO), VTT Technical Research Centre of Finland
Contributors: Khan, S. A., Saastamoinen, J., Tiensyrjä, K., Nurmi, J.
Number of pages: 8
Pages: 313-320
Publication date: 2011

Host publication information

Title of host publication: Proceedings - IEEE 9th International Conference on Dependable, Autonomic and Secure Computing, DASC 2011
ISBN (Print): 9780769546124
ASJC Scopus subject areas: Computational Theory and Mathematics, Software
Keywords: ABSOLUT, GENESYS, MARTE profile, UML2.0
Source: Scopus
Source ID: 84856116007

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

From theories to game mechanics: Developing a game for training rational numbers

The paper reports the results from an ongoing project that aims to develop an engaging and effective digital game for training conceptual rational number knowledge. The overall research approach is design science. In the paper we report the results of an iteration in which we studied how students used a Semideus School game prototype and how they experienced the core mechanics of the game. 20 fourth graders and 32 sixth graders played Semideus School game for approximately 2.5 hours. Students were allowed to freely play the game with their iPads. Playing experience was studied with a digital questionnaire that included items about flow experience (Flow Short Scale), perceived playability, and acceptance of game-based math training. Additionally, a researcher observed the playing sessions and discussed with the students about the implementation of the game. Students experienced reasonable high flow experience while playing the game. The results revealed that 4th graders would be more willing to study rational numbers with a game and they also appreciated the playability of the game more than sixth graders. Moreover, sixth graders demanded more complex game mechanics, but 4th graders were happy with the core mechanics. We redesigned the game mechanics based on the findings. The paper describes the new mechanics and the theoretical basis of the new design.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Pervasive Computing
Contributors: Kiili, K.
Number of pages: 7
Pages: 328-334
Publication date: 2017

Host publication information

Title of host publication: Proceedings of the 11th European Conference on Games Based Learning, ECGBL 2017
Publisher: Academic Conferences and Publishing International Limited
ISBN (Electronic): 9781911218562
ASJC Scopus subject areas: Software, Computer Graphics and Computer-Aided Design, Computer Networks and Communications, Artificial Intelligence, Human-Computer Interaction, Control and Systems Engineering, Education
Keywords: Game design, Game mechanic, Game-based learning, Mathematics, Playing experience, Rational numbers
Source: Scopus
Source ID: 85036471818

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

Inkjet-printed monopole antennas for enhanced-range WBAN and wearable biomonitoring application

In this paper, a monopole antenna backed by an inkjet-printed electromagnetic band gap ground (EBG) plane on paper substrate is proposed for wearable applications with drastically enhanced communication range. This novel design approach for WBAN and wearable biomonitoring applications alleviates the on-body antenna's performance degradation, which may cause a significant degradation of the wireless system's performance as well. The communication range improvement compared to conventional antenna is demonstrated by using a benchmarking commercial wireless temperature sensor module. In addition, the advantages and the integrability of the proposed wearable antenna topology into mobile wireless on-body health care systems is discussed in detail.

General information

Publication status: Published
MoE publication type: A4 Article in a conference publication
Organisations: Sensing Systems for Wireless Medicine (MediSense), Georgia Institute of Technology, University of Tokyo
Contributors: Kim, S., Kawahara, Y., Tentzeris, M. M.
Number of pages: 6
Pages: 33-38
Publication date: 2012

Host publication information

Title of host publication: MobileHealth'12 - Proceedings of the 2nd ACM International Workshop on Pervasive Wireless Healthcare
ISBN (Print): 9781450312929
ASJC Scopus subject areas: Software, Hardware and Architecture, Computer Networks and Communications
Keywords: electromagnetic band gap (ebg) structure, inkjet printing, personal area networks (pans), system level antenna integration, wearable antenna, wireless body area networks (wbans)
Source: Scopus
Source ID: 84863544257

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

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

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

Data Rate Assessment on L2–L3 CPU Bus and Bus between CPU and RAM in Modern CPUs

In this paper, modern CPU architecture with several different cache levels is described and current CPU performance limitations such as frequency increase bounds are discussed. As changes to the currently existing architecture are usually proposed as a way of increasing CPU performance, data rates of the internal and external CPU interfaces must be known. This information would help to assess the applicability of proposed solutions and to optimize them. This paper is aimed at obtaining real values of traffic on an L2–L3 cache interface inside a CPU and a CPU–RAM bus load, as well as showing the dependences of the total traffic on the studied interfaces on the number of active cores, CPU frequency, and test type. A measurement methodology using an Intel Performance Counter Monitor is provided and the equations used to obtain data rates from the internal CPU counters are explained. Both real-life and synthetic tests are described. The dependence of total traffic on the number of active cores and the dependence of total traffic on CPU frequency are provided as plots. The dependence of total traffic on test type is provided as a bar plot for multiple CPU frequencies.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Yaroslavl State University
Contributors: Komar, M. S.
Number of pages: 8
Pages: 701-708
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: Automatic Control and Computer Sciences
Volume: 51
Issue number: 7
ISSN (Print): 0146-4116
Ratings: 
  • Scopus rating (2017): CiteScore 0.6 SJR 0.218 SNIP 0.613
Original language: English
ASJC Scopus subject areas: Software, Control and Systems Engineering, Signal Processing
Keywords: data rate assessment, multicore CPUs, Network-on-Chip, NoC, System-on-Chip, Wireless Network- on-Chip, WNoC

Bibliographical note

INT=elt,"Komar, M. S."

Source: Scopus
Source ID: 85042229432

Research output: Contribution to journalArticleScientificpeer-review

A simulation case study of production planning and control in printed wiring board manufacturing

Production planning and control in printed wiring board (PWB) manufacturing is becoming more difficult as PWB's technology is developing and the production routings become more complex. Simultaneously, the strategic importance of delivery accuracy, short delivery times, and production flexibility is increasing with the highly fluctuating demand and short product life cycles of end products. New principles, that minimize throughput time while guaranteering excellent customer service and adequate capacity utilization, are needed for production planning and control. Simulation is needed in order to develop the new principles and test their superiority. This paper presents an ongoing simulation product that aims at developing the production planning and control of a PWB manufacturer. In the project, a discrete event simulation model is built of a pilot case factory. The model is used for comparing the effect of scheduling, queuing rules, buffer policies, and lot sizes on customer service and cost efficiency.

General information

Publication status: Published
MoE publication type: Not Eligible
Organisations: Industrial Engineering and Management, Aalto University, TAI Research Centre
Contributors: Korhonen, H. M. E., Heikkilä, J., Törnwall, J. M.
Number of pages: 4
Pages: 844-847
Publication date: 1 Dec 2001
Peer-reviewed: Yes

Publication information

Journal: Winter Simulation Conference Proceedings
Volume: 2
ISSN (Print): 0275-0708
Ratings: 
  • Scopus rating (2001): SJR 0.377
Original language: English
ASJC Scopus subject areas: Chemical Health and Safety, Software, Safety, Risk, Reliability and Quality, Applied Mathematics, Modelling and Simulation
Source: Scopus
Source ID: 0035708229

Research output: Contribution to journalConference articleScientificpeer-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

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

Pure e-learning course in information security

We describe key elements and contents of an e-learning course on practical information security that deals with awareness and skills required in daily life. We have had good results in reaching the learning goals and in low resource consuming nature from a teacher's point of view. From a student's point of view the course has been laborious but very instructive and meaningful. We outline also the opportunities of using such a course to contribute to work for information security awareness and usability studies.

General informati