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

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

General information

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

Publication information

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

Research output: Contribution to journalArticleScientificpeer-review

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

Characterizing Resource Allocation Trade-Offs in 5G NR Serving Multicast and Unicast Traffic

The use of highly directional antenna radiation patterns for both the access point (AP) and the user equipment (UE) in the emerging millimeter-wave (mmWave)-based New Radio (NR) systems is inherently beneficial for unicast transmissions by providing an extension of the coverage range and eventually resulting in lower required NR AP densities. On the other hand, efficient resource utilization for serving multicast sessions demands narrower antenna directivities, which yields a trade-off between these two types of traffic that eventually affects the system deployment choices. In this work, with the tools from queuing theory and stochastic geometry, we develop an analytical framework capturing both the distance- and traffic-related aspects of the NR AP serving a mixture of multicast and unicast traffic. Our numerical results indicate that the service process of unicast sessions is severely compromised when (i) the fraction of unicast sessions is significant, (ii) the spatial session arrival intensity is high, or (iii) the service time of the multicast sessions is longer than that of the unicast sessions. To balance the multicast and unicast session drop probabilities, an explicit prioritization is required. Furthermore, for a given fraction of multicast sessions, lower antenna directivity at the NR AP characterized by a smaller NR AP inter-site distance (ISD) leads to a better performance in terms of multicast and unicast session drop probabilities. Aiming to increase the ISD, while also maintaining the drop probability at the target level, the serving of multicast sessions is possible over the unicast mechanisms, but it results in worse performance for the practical NR AP antenna configurations. However, this approach may become feasible as arrays with higher numbers of antenna elements begin to be available. Our developed mathematical framework can be employed to estimate the parameters of the NR AP when handling a mixture of multicast and unicast sessions as well as drive a lower bound on the density of the NR APs, which is needed to serve a certain mixture of multicast and unicast traffic types with their target performance requirements.

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: Samuylov, A., Moltchanov, D., Kovalchukov, R., Pirmagomedov, R., Gaidamaka, Y., Andreev, S., Koucheryavy, Y., Samouylov, K.
Number of pages: 14
Pages: 3421-3434
Publication date: 1 May 2020
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Wireless Communications
Volume: 19
Issue number: 5
Article number: 9003488
ISSN (Print): 1536-1276
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering, Applied Mathematics
Keywords: 5G mobile communication, directional multicasting, millimeter wave communication, multicast communication, resource management
Source: Scopus
Source ID: 85084923005

Research output: Contribution to journalArticleScientificpeer-review

TinderMIX: Time-dose integrated modelling of toxicogenomics data

BACKGROUND: Omics technologies have been widely applied in toxicology studies to investigate the effects of different substances on exposed biological systems. A classical toxicogenomic study consists in testing the effects of a compound at different dose levels and different time points. The main challenge consists in identifying the gene alteration patterns that are correlated to doses and time points. The majority of existing methods for toxicogenomics data analysis allow the study of the molecular alteration after the exposure (or treatment) at each time point individually. However, this kind of analysis cannot identify dynamic (time-dependent) events of dose responsiveness. RESULTS: We propose TinderMIX, an approach that simultaneously models the effects of time and dose on the transcriptome to investigate the course of molecular alterations exerted in response to the exposure. Starting from gene log fold-change, TinderMIX fits different integrated time and dose models to each gene, selects the optimal one, and computes its time and dose effect map; then a user-selected threshold is applied to identify the responsive area on each map and verify whether the gene shows a dynamic (time-dependent) and dose-dependent response; eventually, responsive genes are labelled according to the integrated time and dose point of departure. CONCLUSIONS: To showcase the TinderMIX method, we analysed 2 drugs from the Open TG-GATEs dataset, namely, cyclosporin A and thioacetamide. We first identified the dynamic dose-dependent mechanism of action of each drug and compared them. Our analysis highlights that different time- and dose-integrated point of departure recapitulates the toxicity potential of the compounds as well as their dynamic dose-dependent mechanism of action.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, Tampere University, University of Helsinki
Contributors: Serra, A., Fratello, M., Del Giudice, G., Saarimäki, L. A., Paci, M., Federico, A., Greco, D.
Publication date: 1 May 2020
Peer-reviewed: Yes

Publication information

Journal: GigaScience
Volume: 9
Issue number: 5
ISSN (Print): 2047-217X
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Health Informatics
Keywords: BMD, dose-response, dynamic dose-dependent, gene expression, integrated modeling, mechanism of action, MOA, time course, toxicogenomics
Electronic versions: 
Source: Scopus
Source ID: 85085537918

Research output: Contribution to journalArticleScientificpeer-review

Utilizing Neurons for Digital Logic Circuits: A Molecular Communications Analysis

With the advancement of synthetic biology, several new tools have been conceptualized over the years as alternative treatments for current medical procedures. As part of this work, we investigate how synthetically engineered neurons can operate as digital logic gates that can be used towards bio-computing inside the brain and its impact on epileptic seizure-like behaviour. We quantify the accuracy of logic gates under high firing rates amid a network of neurons and by how much it can smooth out uncontrolled neuronal firings. To test the efficacy of our method, simulations composed of computational models of neurons connected in a structure that represents a logic gate are performed. Our simulations demonstrate the accuracy of performing the correct logic operation, and how specific properties such as the firing rate can play an important role in the accuracy. As part of the analysis, the mean squared error is used to quantify the quality of our proposed model and predict the accurate operation of a gate based on different sampling frequencies. As an application, the logic gates were used to smooth out epileptic seizure-like activity in a biological neuronal network, where the results demonstrated the effectiveness of reducing its mean firing rate. Our proposed system has the potential to be used in future approaches to treating neurological conditions in the brain.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Waterford Institute of Technology, Tampere University, Telecommunications Software and Systems Group (TSSG)
Contributors: Adonias, G. L., Yastrebova, A., Barros, M. T., Koucheryavy, Y., Cleary, F., Balasubramaniam, S.
Number of pages: 13
Pages: 224-236
Publication date: 1 Apr 2020
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Nanobioscience
Volume: 19
Issue number: 2
ISSN (Print): 1536-1241
Original language: English
ASJC Scopus subject areas: Biotechnology, Bioengineering, Medicine (miscellaneous), Biomedical Engineering, Pharmaceutical Science, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Boolean algebra, Logic gates, nano communications, nanonetworks, synthetic biology

Bibliographical note

EXT="Balasubramaniam, Sasitharan"

Source: Scopus
Source ID: 85083430394

Research output: Contribution to journalArticleScientificpeer-review

In-flightwind field identification and prediction of parafoil systems

The wind field is an essential factor that affects accurate homing and flare landing of parafoil systems. In order to obtain the ambient wind field during the descent of a parafoil system, a combination method of in-flight wind field identification and prediction is proposed. First, a wind identification method only using global position system information is derived based on the flight dynamics of parafoil systems. Then a wind field prediction model is constructed using the atmospheric dynamics, and the low-altitude wind field is predicted based on the identified wind field of high-altitude. Finally, simulations of wind field identification and prediction are conducted. The results demonstrate that the proposed method can identify the wind fields precisely and also predict the wind fields reasonably. This method can potentially be applied in practical parafoil systems to provide wind field information for homing tasks.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Anhui Science and Technology University, Aalto University, Peking University, University of Applied Sciences Upper Austria, School of Management, Nankai University, Deprtment of Electrical Engineering and Automation
Contributors: Gao, H., Tao, J., Dehmer, M., Emmert-Streib, F., Sun, Q., Chen, Z., Xie, G., Zhou, Q.
Publication date: 1 Mar 2020
Peer-reviewed: Yes

Publication information

Journal: Applied Sciences (Switzerland)
Volume: 10
Issue number: 6
Article number: 1958
ISSN (Print): 2076-3417
Original language: English
ASJC Scopus subject areas: Materials Science(all), Instrumentation, Engineering(all), Process Chemistry and Technology, Computer Science Applications, Fluid Flow and Transfer Processes
Keywords: Autonomous homing, Identification, Parafoil system, Prediction, Wind field
Source: Scopus
Source ID: 85082646563

Research output: Contribution to journalArticleScientificpeer-review

Anthropometric clothing measurements from 3D body scans

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

General information

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

Publication information

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

Research output: Contribution to journalArticleScientificpeer-review

Data augmentation approaches for improving animal audio classification

In this paper we present ensembles of classifiers for automated animal audio classification, exploiting different data augmentation techniques for training Convolutional Neural Networks (CNNs). The specific animal audio classification problems are i) birds and ii) cat sounds, whose datasets are freely available. We train five different CNNs on the original datasets and on their versions augmented by four augmentation protocols, working on the raw audio signals or their representations as spectrograms. We compared our best approaches with the state of the art, showing that we obtain the best recognition rate on the same datasets, without ad hoc parameter optimization. Our study shows that different CNNs can be trained for the purpose of animal audio classification and that their fusion works better than the stand-alone classifiers. To the best of our knowledge this is the largest study on data augmentation for CNNs in animal audio classification audio datasets using the same set of classifiers and parameters. Our MATLAB code is available at https://github.com/LorisNanni.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, Research group: Computational Biophysics and Imaging Group, Universita degli Studi di Padova, Italy
Contributors: Nanni, L., Maguolo, G., Paci, M.
Number of pages: 8
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Ecological Informatics
Volume: 57
Article number: 101084
ISSN (Print): 1574-9541
Original language: English
ASJC Scopus subject areas: Ecology, Evolution, Behavior and Systematics, Ecology, Modelling and Simulation, Ecological Modelling, Computer Science Applications, Computational Theory and Mathematics, Applied Mathematics
Keywords: Acoustic features, Animal audio, Audio classification, Data augmentation, Ensemble of classifiers, Pattern recognition
URLs: 
Source: Scopus
Source ID: 85082116223

Research output: Contribution to journalArticleScientificpeer-review

Correlates of social media fatigue and academic performance decrement: A large cross-sectional study

Purpose: The current study aims to investigate if different measures related to online psychosocial well-being and online behavior correlate with social media fatigue. Design/methodology/approach: To understand the antecedents and consequences of social media fatigue, the stressor-strain-outcome (SSO) framework is applied. The study consists of two cross-sectional surveys that were organized with young-adult students. Study A was conducted with 1,398 WhatsApp users (aged 19 to 27 years), while Study B was organized with 472 WhatsApp users (aged 18 to 23 years). Findings: Intensity of social media use was the strongest predictor of social media fatigue. Online social comparison and self-disclosure were also significant predictors of social media fatigue. The findings also suggest that social media fatigue further contributes to a decrease in academic performance. Originality/value: This study builds upon the limited yet growing body of literature on a theme highly relevant for scholars, practitioners as well as social media users. The current study focuses on examining different causes of social media fatigue induced through the use of a highly popular mobile instant messaging app, WhatsApp. The SSO framework is applied to explore and establish empirical links between stressors and social media fatigue.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Department of Computer Science, Aalto University, Department of Information Sciences and Technology, George Mason University, Turun Kauppakorkeakoulu, North-West University
Contributors: Malik, A., Dhir, A., Kaur, P., Johri, A.
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: INFORMATION TECHNOLOGY AND PEOPLE
ISSN (Print): 0959-3845
Original language: English
ASJC Scopus subject areas: Information Systems, Computer Science Applications, Library and Information Sciences
Keywords: Academic performance decrement, Fear of missing out (FoMO), Online privacy, Self-disclosure, Social comparison, Social media fatigue
Source: Scopus
Source ID: 85081375513

Research output: Contribution to journalArticleScientificpeer-review

Lage und Zukunft des wissenschaftlichen Nachwuchses: Eine Stellungnahme des Beirats des Wissenschaftlichen Nachwuchses (WiN) der Gesellschaft für Informatik (GI e. V.)

The Advisory Board for Junior Scientific Staff (WiN) of the German Informatics Society (GI) calls for and recommends measures to improve the situation of doctoral candidates and post-doctoral researchers in computer science and other technical sciences. Doctoral and postdoctoral scientists in the field of computer science are increasingly affected by the complex structural and financial problems of academia. The bottleneck on the way to a professorship leads to precarious employment conditions in academic careers. The difficulty in combining family and academic careers creates an additional disadvantage, especially for female scientists. A lack of quality assurance and reliable and transparent decision-making processes make it difficult to identify and deal with conflicts during the doctoral and postdoctoral period. Misguided incentives in the academic system impair the direct, intensive and regular supervision of early career researchers. Timely coping with the challenges outlined in this paper is of central importance for the future survival of university research institutions and for a successful continuation of the principle of best selection. In addition to measures already planned and implemented to empower early career researchers, this paper outlines concrete measures to improve supervision during the doctoral phase, and to structure and create further career paths in academia.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, Beirat des Wissenschaftlichen Nachwuchses der Gesellschaft für Informatik (GI WiN), University of York, Technische Hochschule Ingolstadt, Universitat Potsdam, bitGilde IT Solutions UG (haftungsbeschränkt), Brandenburgische Technische Universität Cottbus-Senftenberg, Universität Hamburg
Contributors: Lenk, K., Gleirscher, M., Nestler, S., Rödiger, S., Petersen, T., Loebel, J. M.
Number of pages: 9
Pages: 94–102
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Informatik-Spektrum
Volume: 43
Issue number: 2
ISSN (Print): 0170-6012
Original language: German
ASJC Scopus subject areas: Information Systems, Computer Science Applications
Source: Scopus
Source ID: 85080076017

Research output: Contribution to journalArticleScientificpeer-review

Game-theoretic semantics for ATL+ with applications to model checking

We develop a game-theoretic semantics (GTS) for the fragment ATL+ of the alternating-time temporal logic ATL, thereby extending the recently introduced GTS for ATL. We show that the game-theoretic semantics is equivalent to the standard compositional semantics of ATL+ with perfect-recall strategies. Based on the new semantics, we provide an analysis of the memory and time resources needed for model checking ATL+ and show that strategies of the verifier that use only a very limited amount of memory suffice. Furthermore, using the GTS, we provide a new algorithm for model checking ATL+ and identify a natural hierarchy of tractable fragments of ATL+ that substantially extend ATL.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Stockholm University, University of Johannesburg, Tampere University
Contributors: Goranko, V., Kuusisto, A., Rönnholm, R.
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: Information and Computation
Article number: 104554
ISSN (Print): 0890-5401
Original language: English
ASJC Scopus subject areas: Theoretical Computer Science, Information Systems, Computer Science Applications, Computational Theory and Mathematics
Keywords: Algorithmic model checking, Alternating-time temporal logic, Finite memory strategies, Game-theoretic semantics, Tractable fragments
Source: Scopus
Source ID: 85082775187

Research output: Contribution to journalArticleScientificpeer-review

Modified Wilkinson power divider with harmonics suppression and compact size for GSM applications

In this article, a modified microstrip Wilkinson power divider with harmonics suppression for GSM communications applications is presented. For low-pass filter designing, one open stub, one radial resonator, and two rectangular resonators are used. According to results related to insertion losses (|S21| and |S31|), stopband is wide and equal to 7.5 GHz (3.4-10.9 GHz), under the condition of 20 dB harmonic suppression level. The results show that at the designed frequency of 1.8 GHz, the input return loss (|S11|) and output return losses (|S22| and |S33|) are better than 22 dB, and the isolation between of output ports (|S32|) is better than 30 dB. The size of the proposed power divider is compact and equal to 10.6 × 14.6 mm2. Finally, the proposed power divider was fabricated and the measurement results illustrate a good agreement with simulation results.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, Islamic Azad University, Arak Branch
Contributors: Moloudian, G., Miri Rostami, S. R., Björninen, T.
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: International Journal of RF and Microwave Computer-Aided Engineering
ISSN (Print): 1096-4290
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Graphics and Computer-Aided Design, Electrical and Electronic Engineering
Keywords: harmonics suppression, low-pass filter, microstrip, Wilkinson power divider
Source: Scopus
Source ID: 85082326650

Research output: Contribution to journalArticleScientificpeer-review

Who contributes what? Scrutinizing the activity data of 4.2 million Zhihu users via immersion scores

Studies of knowledge communities have focused predominantly on contributors who ask questions and/or post replies, while little research has examined the contributions of those who neither pose questions nor suggest answers in knowledge communities. To illuminate member contributions of various sorts, this study evaluated user contribution to knowledge community from three dimensions (influence, content-contribution, and activeness) of immersion. Based on the user activity data of more than 4 million users from Zhihu, the largest online knowledge community in China, we calculated the immersion level for the four user groups (Lurkers, Questioners, Answerers, and Questioner-Answerers) in line with their question-asking and question-answering behaviors in Zhihu. The research findings revealed that Lurkers (members who posted nothing) showed higher community-immersion score than Questioners who asked questions only. The latter, Questioners, had the lowest community-immersion score, while Questioner-Answerers, who posted both questions and answers, exhibited the greatest contribution in the case knowledge community. We further made horizontal comparison of immersion score among the four different user groups, and found that when immersion scores of the four different user groups are above a certain threshold, the immersion scores of the four different user groups display a consistent distinguishing pattern. This result highlights the similarity of tendencies in behavioral orientation among different users in knowledge communities. Theoretical contributions and practical implications to be gleaned from this research are discussed.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Information and Knowledge Management, Wuhan University, Aalto University
Contributors: Deng, S., Jiang, Y., Li, H., Liu, Y.
Number of pages: 14
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: INFORMATION PROCESSING AND MANAGEMENT
Volume: 57
Issue number: 5
Article number: 102274
ISSN (Print): 0306-4573
Original language: English
ASJC Scopus subject areas: Information Systems, Media Technology, Computer Science Applications, Management Science and Operations Research, Library and Information Sciences
Keywords: Contribution, Immersion score, Knowledge community, SQA community, User engagement
Source: Scopus
Source ID: 85084937639

Research output: Contribution to journalArticleScientificpeer-review

Social media overload, exhaustion, and use discontinuance: Examining the effects of information overload, system feature overload, and social overload

While users’ discontinuance of use has posed a challenge for social media in recent years, there is a paucity of knowledge on the relationships between different dimensions of overload and how overload adversely affects users’ social media discontinuance behaviors. To address this knowledge gap, this study employed the stressor–strain–outcome (SSO) framework to explain social media discontinuance behaviors from an overload perspective. It also conceptualized social media overload as a multidimensional construct consisting of system feature overload, information overload, and social overload. The proposed research model was empirically validated via 412 valid questionnaire responses collected from Facebook users. Our results indicated that the three types of overload are interconnected through system feature overload. System feature overload, information overload, and social overload engender user exhaustion, which in turn leads to users’ discontinued usage of social media. This study extends current technostress research by demonstrating the value of the SSO perspective in explaining users’ social media discontinuance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Information and Knowledge Management, Wuhan University, Aalto University, University of Jyvaskyla
Contributors: Fu, S., Li, H., Liu, Y., Pirkkalainen, H., Salo, M.
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: INFORMATION PROCESSING AND MANAGEMENT
Volume: 57
Issue number: 6
Article number: 102307
ISSN (Print): 0306-4573
Original language: English
ASJC Scopus subject areas: Information Systems, Media Technology, Computer Science Applications, Management Science and Operations Research, Library and Information Sciences
Keywords: Exhaustion, Overload, Social media, Stressor–strain–outcome, Technology discontinuance
Source: Scopus
Source ID: 85086502714

Research output: Contribution to journalArticleScientificpeer-review

Microflow-Based Device for In Vitro and Ex Vivo Drug Permeability Studies

This paper presents a novel microflow-based concept for studying the permeability of in vitro cell models or ex vivo tissues. Using the proposed concept, we demonstrate how to maintain physiologically relevant test conditions and produce highly reproducible permeability values for a range (31) of drug compounds. The apparent permeability coefficients (Papp) showed excellent correlation (0.89) with the values from experiments performed with a conventional Ussing chamber. Additionally, the microflow-based concept produces notably more concentrated samples than the conventional Ussing chamber-based approach, despite the fact that more than 10 times smaller quantities of test compounds and biological membranes are needed in the microflow-based concept.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, School of Pharmacy, University of Eastern Finland, University of Helsinki, St. Petersburg State University
Contributors: Hemmilä, S., Ruponen, M., Toropainen, E., Tengvall-Unadike, U., Urtti, A., Kallio, P.
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: SLAS Technology
ISSN (Print): 2472-6303
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Medical Laboratory Technology
Keywords: ex vivo, in vitro, microfluidics, permeability

Bibliographical note

EXT="Ruponen, Marika"

Source: Scopus
Source ID: 85084825294

Research output: Contribution to journalArticleScientificpeer-review

Development of measurement instrument for visual qualities of graphical user interface elements (VISQUAL): a test in the context of mobile game icons

Graphical user interfaces are widely common and present in everyday human–computer interaction, dominantly in computers and smartphones. Today, various actions are performed via graphical user interface elements, e.g., windows, menus and icons. An attractive user interface that adapts to user needs and preferences is progressively important as it often allows personalized information processing that facilitates interaction. However, practitioners and scholars have lacked an instrument for measuring user perception of aesthetics within graphical user interface elements to aid in creating successful graphical assets. Therefore, we studied dimensionality of ratings of different perceived aesthetic qualities in GUI elements as the foundation for the measurement instrument. First, we devised a semantic differential scale of 22 adjective pairs by combining prior scattered measures. We then conducted a vignette experiment with random participant (n = 569) assignment to evaluate 4 icons from a total of pre-selected 68 game app icons across 4 categories (concrete, abstract, character and text) using the semantic scales. This resulted in a total of 2276 individual icon evaluations. Through exploratory factor analyses, the observations converged into 5 dimensions of perceived visual quality: Excellence/Inferiority, Graciousness/Harshness, Idleness/Liveliness, Normalness/Bizarreness and Complexity/Simplicity. We then proceeded to conduct confirmatory factor analyses to test the model fit of the 5-factor model with all 22 adjective pairs as well as with an adjusted version of 15 adjective pairs. Overall, this study developed, validated, and consequently presents a measurement instrument for perceptions of visual qualities of graphical user interfaces and/or singular interface elements (VISQUAL) that can be used in multiple ways in several contexts related to visual human-computer interaction, interfaces and their adaption.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Gamification Group
Contributors: Jylhä, H., Hamari, J.
Publication date: 2020
Peer-reviewed: Yes

Publication information

Journal: User Modeling and User-Adapted Interaction
ISSN (Print): 0924-1868
Original language: English
ASJC Scopus subject areas: Education, Human-Computer Interaction, Computer Science Applications
Keywords: Adaptive user interfaces, Aesthetics, Design guidelines, Graphical user interface, Measurement instrument, Questionnaire
Source: Scopus
Source ID: 85085161179

Research output: Contribution to journalArticleScientificpeer-review

Empowering Heterogeneous Communication Data Links in General Aviation through mmWave Signals

We study data transfer links that would enable development of low-cost technologies for increasing safety of general aviation (GA). The solution proposed here is to supplement the existing cmWave solutions with mmWave cellular signals in order to better handle interferences and to reach lower outage probabilities and higher throughputs. Moreover, cellular solutions have the advantage of re-using existing or planned infrastructure, and thus they are expected to require minor additional investments. Our article aims both at shedding some light on the terminology in the GA field and at proposing future viable data-link solutions in GA. We also survey the existing solutions, challenges, and opportunities related to the wireless communication links in GA, and we present several case studies related to the achievable outage probabilities and throughputs under rural and urban scenarios of low-altitude GA vehicles. We conclude that supplementing the existing cmWave wireless links with mmWave wireless connections is a workable solution for affordable communication links for low-altitude GA aircraft.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research group: Wireless Communications and Positioning, Honeywell Advanced Technology Europe, Joined Honeywell Advanced Technology Europe, Airbus
Contributors: Wang, W., Talvitie, J., Adamova, E. J., Fath, T., Korenciak, L., Valkama, M., Lohan, E. S.
Number of pages: 8
Pages: 164-171
Publication date: 6 Dec 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 26
Issue number: 6
Article number: 8926332
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2019): SJR 3.764 SNIP 4.105
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Additional files: 
Source: Scopus
Source ID: 85076292723

Research output: Contribution to journalArticleScientificpeer-review

Motivating scholars’ responses in academic social networking sites: An empirical study on ResearchGate Q&A behavior

The advent of academic social networking sites (ASNS) has offered an unprecedented opportunity for scholars to obtain peer support online. However, little is known about the characteristics that make questions and answers popular among scholars on ASNS. Focused on the statements embedded in questions and answers, this study strives to explore the precursors that motivate scholars to respond, such as reading, following, or recommending a question or an answer. We collected empirical data from ResearchGate and coded the data via the act4teams coding scheme. Our analysis revealed a threshold effect—when the length of question description is over circa 150 words, scholars would quickly lose interest and thus not read the description. In addition, we found that questions, including positive action-oriented statements, are more likely to entice subsequent reads from other scholars. Furthermore, scholars prefer to recommend an answer with positive procedural statements or negative action-oriented statements.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Information and Knowledge Management, Wuhan University, Aalto University
Contributors: Deng, S., Tong, J., Lin, Y., Li, H., Liu, Y.
Publication date: 1 Nov 2019
Peer-reviewed: Yes

Publication information

Journal: INFORMATION PROCESSING AND MANAGEMENT
Volume: 56
Issue number: 6
Article number: 102082
ISSN (Print): 0306-4573
Ratings: 
  • Scopus rating (2019): SJR 1.192 SNIP 3.199
Original language: English
ASJC Scopus subject areas: Information Systems, Media Technology, Computer Science Applications, Management Science and Operations Research, Library and Information Sciences
Keywords: Library and information science, ResearchGate, Social Q&A
Source: Scopus
Source ID: 85070729878

Research output: Contribution to journalArticleScientificpeer-review

Deliberate or Instinctive? Proactive and Reactive Coping for Technostress

Employees in organizations face technostress that is, stress from information technology (IT) use. Although technostress is a highly prevalent organizational phenomenon, there is a lack of theory-based understanding on how IT users can cope with it. We theorize and validate a model for deliberate proactive and instinctive reactive coping for technostress. Drawing from theories on coping, our model posits that the reactive coping behaviors of distress venting and distancing from IT can alleviate technostress by diminishing the negative effect of technostress creators on IT-enabled productivity. The proactive coping behaviors of positive reinterpretation and IT control can help IT users by influencing the extent to which reactive coping behaviors are effective and by positively influencing IT-enabled productivity. The findings of a cross-sectional survey study of 846 organizational IT users support the model. The paper provides a new theoretical contribution by identifying ways in which organizational IT users can cope with technostress.

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 Jyvaskyla, Information Systems and Co-Director of the Centre for Technological Futures at Lancaster University (Management School)
Contributors: Pirkkalainen, H., Salo, M., Tarafdar, M., Makkonen, M.
Number of pages: 34
Pages: 1179-1212
Publication date: 2 Oct 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Management Information Systems
Volume: 36
Issue number: 4
ISSN (Print): 0742-1222
Ratings: 
  • Scopus rating (2019): SJR 2.863 SNIP 2.585
Original language: English
ASJC Scopus subject areas: Management Information Systems, Computer Science Applications, Management Science and Operations Research, Information Systems and Management
Keywords: information systems use, proactive coping, reactive coping, technostress, technostress coping

Bibliographical note

EXT="Makkonen, Markus"

Source: Scopus
Source ID: 85073528603

Research output: Contribution to journalArticleScientificpeer-review

DevOps in practice: A multiple case study of five companies

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

General information

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

Publication information

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

Bibliographical note

EXT="Mikkonen, Tommi"

Source: Scopus
Source ID: 85068546035

Research output: Contribution to journalArticleScientificpeer-review

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

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

General information

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

Publication information

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

Research output: Contribution to journalArticleScientificpeer-review

Hermitian normalized Laplacian matrix for directed networks

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

General information

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

Publication information

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

Research output: Contribution to journalArticleScientificpeer-review

Internet of Autonomous Vehicles: Architecture, Features, and Socio-Technological Challenges

Mobility is the backbone of urban life and a vital economic factor in the development of the world. Rapid urbanization and the growth of mega-cities are bringing dramatic changes in the capabilities of vehicles. Innovative solutions like autonomy, electrification, and connectivity are on the horizon. How, then, we can provide ubiquitous connectivity to legacy and autonomous vehicles? This article seeks to answer this question by combining recent leaps of innovation in network virtualization with remarkable feats of wireless communications. To do so, this article proposes a novel paradigm called the Internet of Autonomous Vehicles (IoAV). We begin painting the picture of IoAV by discussing the salient features and applications of IoAV, followed by a detailed discussion on the key enabling technologies. Next, we describe the proposed layered architecture of IoAV and uncover some critical functions of each layer. This is followed by the performance evaluation of IoAV, which shows significant advantages of the proposed architecture in terms of transmission time and energy consumption. Finally, to best capture the benefits of IoAV, we enumerate some social and technological challenges, and explain how some unresolved issues can disrupt the widespread use of autonomous vehicles in the future.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences
Contributors: Jameel, F., Chang, Z., Huang, J., Ristaniemi, T.
Number of pages: 9
Pages: 21-29
Publication date: 1 Aug 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 26
Issue number: 4
Article number: 8809655
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2019): SJR 3.764 SNIP 4.105
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85071324963

Research output: Contribution to journalArticleScientificpeer-review

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

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

General information

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

Publication information

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

Research output: Contribution to journalArticleScientificpeer-review

Energy Efficiency of Multi-Radio Massive Machine-Type Communication (MR-MMTC): Applications, Challenges, and Solutions

While the IoT has made significant progress along the lines of supporting its individual applications, there are many MMTC scenarios in which the performance offered by any single RAT available today might be insufficient. To address these use cases, we introduce the concept of MR-MMTC, which implies the availability and utilization of several RATs within a single IoT device. We begin by offering insights into which use cases could be beneficial and what the key challenges for MR-MMTC implementation are. We continue by discussing the potential technical solutions and employing our own prototype of an MR-MMTC device capable of using LoRaWAN and NB-IoT RATs to characterize its energy-centric performance across the alternative feasible MR-MMTC implementation strategies. The obtained results reveal that an increased flexibility delivered by MR-MMTC permits the selection of more energy-efficient RAT options. The IoT devices capable of utilizing multiple radios simultaneously can thus improve their energy utilization by leveraging the synergy between RATs. The novel vision of MR-MMTC outlined in this work could be impactful across multiple fields, and calls for cross-community research efforts in order to adequately design, implement, and deploy future multi-RAT MMTC solutions.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, University of Oulu, Actility S.A., King’s College London
Contributors: Mikhaylov, K., Petrov, V., Gupta, R., Lema, M. A., Galinina, O., Andreev, S., Koucheryavy, Y., Valkama, M., Pouttu, A., Dohler, M.
Number of pages: 7
Pages: 100-106
Publication date: 1 Jun 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 57
Issue number: 6
Article number: 8694791
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2019): SJR 4.025 SNIP 4.403
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85065138396

Research output: Contribution to journalArticleScientificpeer-review

Socially inspired relaying and proactive mode selection in mmWave vehicular communications

As the Internet of Vehicles matures and acquires its social flavor, novel wireless connectivity enablers are being demanded for reliable data transfer in high-rate applications. The recently ratified New Radio communications technology operates in millimeter-wave (mmWave) spectrum bands and offers sufficient capacity for bandwidth-hungry services. However, seamless operation over mmWave is difficult to maintain on the move, since such extremely high frequency radio links are susceptible to unexpected blockage by various obstacles, including vehicle bodies. As a result, proactive mode selection, that is, migration from infrastructure- to vehicle-based connections and back, is becoming vital to avoid blockage situations. Fortunately, the very social structure of interactions between the neighboring smart cars and their passengers may be leveraged to improve session continuity by relaying data via proximate vehicles. This paper conceptualizes the socially inspired relaying scenarios, conducts underlying mathematical analysis, continues with a detailed 3-D modeling to facilitate proactive mode selection, and concludes by discussing a practical prototype of a vehicular mmWave platform.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, University of California, Los Angeles
Contributors: Moltchanov, D., Kovalchukov, R., Gerasimenko, M., Andreev, S., Koucheryavy, Y., Gerla, M.
Number of pages: 12
Pages: 5172-5183
Publication date: 1 Jun 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Internet of Things Journal
Volume: 6
Issue number: 3
ISSN (Print): 2327-4662
Ratings: 
  • Scopus rating (2019): SJR 2.607 SNIP 4.11
Original language: English
ASJC Scopus subject areas: Signal Processing, Information Systems, Hardware and Architecture, Computer Science Applications, Computer Networks and Communications
Keywords: Internet of Things, Millimeter wave (mmWave) communication, Social network services, Vehicular ad hoc networks
Electronic versions: 
Source: Scopus
Source ID: 85067875266

Research output: Contribution to journalArticleScientificpeer-review

Future of Ultra-Dense Networks Beyond 5G: Harnessing Heterogeneous Moving Cells

For the past 40 years, the cellular industry has been relying on static radio access deployments with gross over-provisioning. However, to meet the exponentially growing volumes of irregular data, the very notion of a cell will have to be rethought to allow them be (re-)configured on-demand and in an automated manner. This work puts forward a vision of moving networks to match dynamic user demand with network access supply in beyond-5G cellular systems. The resulting adaptive and flexible network infrastructures will leverage intelligent capable devices (e.g., cars and drones) by employing appropriate user involvement schemes. This work is a recollection of our efforts in this space with the goal to contribute a comprehensive research agenda. Particular attention is paid to quantifying the network performance scaling and session continuity gains with ultra-dense moving cells. Our findings argue for non-incremental benefits of integrating moving access points on a par with conventional (static) cellular access infrastructure.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research group: Wireless Communications and Positioning, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, King’s College London, Carleton University
Contributors: Andreev, S., Petrov, V., Dohler, M., Yanikomeroglu, H.
Number of pages: 27
Pages: 66-92
Publication date: 1 Jun 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 57
Issue number: 6
Article number: 8722593
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2019): SJR 4.025 SNIP 4.403
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85067074122

Research output: Contribution to journalArticleScientificpeer-review

Approximate robust output regulation of boundary control systems

We extend the internal model principle for systems with boundary control and boundary observation, and construct a robust controller for this class of systems. However, as a consequence of the internal model principle, any robust controller for a plant with infinite-dimensional output space necessarily has infinite-dimensional state space. We proceed to formulate the approximate robust output regulation problem and present a finite-dimensional controller structure to solve it. Our main motivating example is a wave equation on a bounded multidimensional spatial domain with force control and velocity observation at the boundary. In order to illustrate the theoretical results, we construct an approximate robust controller for the wave equation on an annular domain and demonstrate its performance with numerical simulations.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Abo Akad Univ, Abo Akademi University, Dept Phys
Contributors: Humaloja, J. P., Kurula, M., Paunonen, L.
Pages: 2210-2223
Publication date: Jun 2019
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: IEEE Transactions on Automatic Control
Volume: 64
Issue number: 6
ISSN (Print): 0018-9286
Ratings: 
  • Scopus rating (2019): SJR 3.908 SNIP 2.582
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Controlled wave equation, Distributed parameter systems, Linear systems, Robust control
Electronic versions: 
Source: Scopus
Source ID: 85057826955

Research output: Contribution to journalArticleScientificpeer-review

On Unified Vehicular Communications and Radar Sensing in Millimeter-Wave and Low Terahertz Bands

Future smart vehicles will incorporate high-data-rate communications and high-resolution radar sensing capabilities operating in the millimeter-wave and higher frequencies. These two systems are preparing to share and reuse many common functionalities, such as steerable millimeter-wave antenna arrays. Motivated by this growing overlap, which is advanced further by space and cost constraints, the vehicular community is pursuing a vision of unified vehicular communications and radar sensing that represents a major paradigm shift for next-generation connected and self-driving cars. This article outlines a path to materialize this decisive transformation. We begin by reviewing the latest developments in hybrid vehicular communications and radar systems, and then propose a concept of unified channel access over millimeter-wave and higher frequencies. Our supporting system-level performance characterization relies upon real-life measurements and extensive ray-based modeling to confirm the significant improvements brought by our proposal to mitigating the interference and deafness effects. Since our results aim to open the door to unified vehicular communications and radar sensing, we conclude by outlining the potential research directions in this rapidly developing field.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Ericsson Research
Contributors: Petrov, V., Fodor, G., Kokkoniemi, J., Moltchanov, D., Lehtomäki, J., Andreev, S., Koucheryavy, Y., Juntti, M., Valkama, M.
Number of pages: 8
Pages: 146-153
Publication date: Jun 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 26
Issue number: 3
Article number: 8722599
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2019): SJR 3.764 SNIP 4.105
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85066981988

Research output: Contribution to journalArticleScientificpeer-review

Dense Moving Fog for Intelligent IoT: Key Challenges and Opportunities

As the ratification of 5G New Radio technology is being completed, enabling network architectures are expected to undertake a matching effort. Conventional cloud and edge computing paradigms may thus become insufficient in supporting the increasingly stringent operating requirements of intelligent IoT devices that can move unpredictably and at high speeds. Complementing these, the concept of fog emerges to deploy cooperative cloud-like functions in the immediate vicinity of various moving devices, such as connected and autonomous vehicles, on the road and in the air. Envisioning the gradual evolution of these infrastructures toward an increasingly denser geographical distribution of fog functionality, we in this work put forward the vision of dense moving fog for intelligent IoT applications. To this aim, we review the recent powerful enablers, outline the main challenges and opportunities, and corroborate the performance benefits of collaborative dense fog operation in a characteristic use case fe.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research group: Wireless Communications and Positioning, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, University of Hong Kong, King’s College London, King's College London
Contributors: Andreev, S., Petrov, V., Huang, K., Lema, M. A., Dohler, M.
Number of pages: 8
Pages: 34-41
Publication date: 1 May 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 57
Issue number: 5
Article number: 8648449
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2019): SJR 4.025 SNIP 4.403
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85062145622

Research output: Contribution to journalArticleScientificpeer-review

Effects of percutaneous transluminal angioplasty of superficial femoral artery on photoplethysmographic pulse transit times

We analyze the changes in upper and lower limb pulse transit times (PTT) caused by peripheral artery disease (PAD) and its treatment with percutaneous transluminal angioplasty (PTA) of the superficial femoral artery. PTTs were extracted from the photoplethysmograms (PPG) recorded from an index finger and 2nd toes. PTTs were defined between the R-peaks of the ECG and different reference points of the (PPG): foot and peak points, maxima of 1st and 2nd derivative, and by means of intersecting tangents method. Also the PTTs between the toe and finger pulses were analyzed. Our sample consists of 24 subjects examined before and after the PTA and in 1-month follow-up visit. Also 28 older than 65 years controls having normal ankle-to-brachial pressure index (ABI) and no history in cardiovascular diseases as well as 21 younger subjects were examined. The differences between the groups and pre- and post-treatment phases were analyzed by means of non-parametric statistical tests. The changes in the PTTs of upper limb and non-treated lower limb were negligible. The agreement with the reference values, ABI and toe pressures, was studied by kappa-analysis, resulting in kappa-values of 0.33<formula><tex>$\times$</tex></formula>0.91. Differences in PTTs were found between pre-treatment state of the treated limb, post-treatment state and the follow-up visit, as well as between the pre-treatment state and controls. If patients' age and systolic blood pressure were taken into consideration, the method of lower limb PTT calculation from the peak point turns out feasible in finding the markers of PAD and monitoring post- treatment vascular remodellation.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Sensor Technology and Biomeasurements (STB), Division of Vascular Surgery, Division of Interventional Radiology, Oulu University Hospital, Tampere University Hospital
Contributors: Peltokangas, M., Suominen, V., Vakhitov, D., Korhonen, J., Verho, J., Mattila, V. M., Romsi, P., Lekkala, J., Vehkaoja, A., Oksala, N.
Pages: 1058-1065
Publication date: May 2019
Peer-reviewed: Yes
Early online date: 27 Jun 2018

Publication information

Journal: IEEE Journal of Biomedical and Health Informatics
Volume: 23
Issue number: 3
ISSN (Print): 2168-2194
Ratings: 
  • Scopus rating (2019): SJR 1.306 SNIP 2.522
Original language: English
ASJC Scopus subject areas: Biotechnology, Computer Science Applications, Electrical and Electronic Engineering, Health Information Management
Keywords: Atherosclerosis, Peripheral artery disease, Photoplethysmography, Pulse wave measurements
Additional files: 
Source: Scopus
Source ID: 85049142393

Research output: Contribution to journalArticleScientificpeer-review

On the complexity of restoring corrupted colorings

In the r-Fix problem, we are given a graph G, a (non-proper) vertex-coloring c: V(G) → [r] , and a positive integer k. The goal is to decide whether a proper r-coloring c is obtainable from c by recoloring at most k vertices of G. Recently, Junosza-Szaniawski et al. (in: SOFSEM 2015: theory and practice of computer science, Springer, Berlin, 2015) asked whether the problem has a polynomial kernel parameterized by the number of recolorings k. In a full version of the manuscript, the authors together with Garnero and Montealegre, answered the question in the negative: for every r≥ 3 , the problem r-Fix does not admit a polynomial kernel unless [InlineEquation not available: see fulltext.]. Independently of their work, we give an alternative proof of the theorem. Furthermore, we study the complexity of r-Swap, where the only difference from r-Fix is that instead of k recolorings we have a budget of k color swaps. We show that for every r≥ 3 , the problem r-Swap is [InlineEquation not available: see fulltext.]-hard whereas r-Fix is known to be FPT. Moreover, when r is part of the input, we observe both Fix and Swap are [InlineEquation not available: see fulltext.]-hard parameterized by the treewidth of the input graph. We also study promise variants of the problems, where we are guaranteed that a proper r-coloring c is indeed obtainable from c by some finite number of swaps. For instance, we prove that for r= 3 , the problems r-Fix-Promise and r-Swap-Promise are [InlineEquation not available: see fulltext.]-hard for planar graphs. As a consequence of our reduction, the problems cannot be solved in 2o(n) time unless the Exponential Time Hypothesis fails.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Bell Labs
Contributors: De Biasi, M., Lauri, J.
Number of pages: 20
Pages: 1150-1169
Publication date: May 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Combinatorial Optimization
Volume: 37
Issue number: 4
ISSN (Print): 1382-6905
Ratings: 
  • Scopus rating (2019): SJR 0.516 SNIP 0.97
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Discrete Mathematics and Combinatorics, Control and Optimization, Computational Theory and Mathematics, Applied Mathematics
Keywords: Combinatorial reconfiguration, Computational complexity, Graph coloring, Local search, Parameterized complexity
Source: Scopus
Source ID: 85053264976

Research output: Contribution to journalArticleScientificpeer-review

Energy-efficient and high-precision control of hydraulic robots

In addition to high-precision closed-loop control performance, energy efficiency is another vital characteristic in field-robotic hydraulic systems as energy source(s) must be carried on board in limited space. This study proposes an energy-efficient and high-precision closed-loop controller for the highly nonlinear hydraulic robotic manipulators. The proposed method is twofold: 1) A possibility for energy consumption reduction is realized by using a separate meter-in separate meter-out (SMISMO) control set-up, enabling an independent metering (pressure control) of each chamber in hydraulic actuators. 2) A novel subsystem-dynamics-based and modular controller is designed for the system actuators, and it is integrated to the previously designed state-of-the-art controller for multiple degrees-of-freedom (n-DOF) manipulators. Stability of the overall controller is rigorously proven. The comparative experiments with a three-DOF redundant hydraulic robotic manipulator (with a payload of 475 kg) demonstrate that: 1) It is possible to design the triple objective of high-precision piston position, piston force and chamber pressure trackings for the hydraulic actuators. 2) In relation to the previous SMISMO-control methods, unprecedented motion and chamber pressure tracking performances are reported. 3) In comparison to the state-of-the-art motion tracking controller with a conventional energy-inefficient servovalve control, the actuators’ energy consumption is reduced by 45% without noticeable motion control (position-tracking) deterioration.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: Innovative Hydraulic Automation, Automation Technology and Mechanical Engineering, Canadian Space Agency
Contributors: Koivumäki, J., Zhu, W. H., Mattila, J.
Number of pages: 18
Pages: 176-193
Publication date: 1 Apr 2019
Peer-reviewed: Yes

Publication information

Journal: Control Engineering Practice
Volume: 85
ISSN (Print): 0967-0661
Ratings: 
  • Scopus rating (2019): SJR 1.148 SNIP 1.835
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Electrical and Electronic Engineering, Applied Mathematics
Keywords: Energy efficiency, Hydraulic robots, Independent metering, Nonlinear control, SMISMO control, Stability analysis
Electronic versions: 
Source: Scopus
Source ID: 85061341920

Research output: Contribution to journalArticleScientificpeer-review

Employing Knowledge on Causal Relationship to Assist Multidisciplinary Design Optimization

With the increasing design dimensionality, it is more difficult to solve multidisciplinary design optimization (MDO) problems. Many MDO decomposition strategies have been developed to reduce the dimensionality. Those strategies consider the design problem as a black-box function. However, practitioners usually have certain knowledge of their problem. In this paper, a method leveraging causal graph and qualitative analysis is developed to reduce the dimensionality of the MDO problem by systematically modeling and incorporating the knowledge about the design problem into optimization. Causal graph is created to show the input-output relationships between variables. A qualitative analysis algorithm using design structure matrix (DSM) is developed to automatically find the variables whose values can be determined without resorting to optimization. According to the impact of variables, an MDO problem is divided into two subproblems, the optimization problem with respect to the most important variables, and the other with variables of lower importance. The novel method is used to solve a power converter design problem and an aircraft concept design problem, and the results show that by incorporating knowledge in form of causal relationship, the optimization efficiency is significantly improved.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation Technology and Mechanical Engineering, Research area: Manufacturing and Automation, Simon Fraser University
Contributors: Wu, D., Coatanea, E., Wang, G. G.
Publication date: Apr 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Mechanical Design, Transactions of the ASME
Volume: 141
Issue number: 4
Article number: 041402
ISSN (Print): 1050-0472
Ratings: 
  • Scopus rating (2019): SJR 0.877 SNIP 1.437
Original language: English
ASJC Scopus subject areas: Mechanics of Materials, Mechanical Engineering, Computer Science Applications, Computer Graphics and Computer-Aided Design
Keywords: causal graph, dimension reduction, dimensional analysis, multidisciplinary design optimization
Source: Scopus
Source ID: 85059942742

Research output: Contribution to journalArticleScientificpeer-review

Layered approach for improving the quality of free-viewpoint depth-image-based rendering images

In free-viewpoint rendering systems, one of the most challenging goals is the creation of virtual views based on available color texture (RGB) and depth data. Conventional depth-image-based rendering (DIBR) approaches have assumed that the virtual camera can only be displaced horizontally, thus leading to fairly simple disocclusion artifacts. However, in free-viewpoint DIBR, the virtual camera can be positioned in an arbitrary way and the respective disocclusion artifacts can exhibit complicated anisotropic appearances. Consequently, conventional approaches for compensating disocclusion holes usually fail in such arbitrary camera motion. We present a disocclusion compensation technique based on texture inpainting. We propose a layered representation of both the color and depth images in local foreground, background, and undefined segments (a trimap). This representation allows for employing an efficient alpha-matting approach for reconstructing the underlying opacity layer followed by a background compensation and layered rendering. The performance of the proposed method is evaluated with respect to the state-of-the-art through objective and subjective tests. The achieved results, especially for large camera displacements, outperform the state-of-the-art. Those results assess the effectiveness of the proposed method and highlight the need for new quality metrics able to address the impairments of this type of content.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Research group: 3D MEDIA, University “Roma Tre”
Contributors: Smirnov, S., Battisti, F., Gotchev, A.
Publication date: 27 Feb 2019
Peer-reviewed: Yes

Publication information

Journal: Journal of Electronic Imaging
Volume: 28
Issue number: 1
Article number: 013049
ISSN (Print): 1017-9909
Ratings: 
  • Scopus rating (2019): SJR 0.264 SNIP 0.566
Original language: English
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics, Computer Science Applications, Electrical and Electronic Engineering
Keywords: depth-image-based rendering, inpainting, multiview, quality, RGB+D

Bibliographical note

EXT="Battisti, Federica"

Source: Scopus
Source ID: 85062623919

Research output: Contribution to journalArticleScientificpeer-review

Iterative unsupervised domain adaptation for generalized cell detection from brightfield z-stacks

Background: Cell counting from cell cultures is required in multiple biological and biomedical research applications. Especially, accurate brightfield-based cell counting methods are needed for cell growth analysis. With deep learning, cells can be detected with high accuracy, but manually annotated training data is required. We propose a method for cell detection that requires annotated training data for one cell line only, and generalizes to other, unseen cell lines. Results: Training a deep learning model with one cell line only can provide accurate detections for similar unseen cell lines (domains). However, if the new domain is very dissimilar from training domain, high precision but lower recall is achieved. Generalization capabilities of the model can be improved with training data transformations, but only to a certain degree. To further improve the detection accuracy of unseen domains, we propose iterative unsupervised domain adaptation method. Predictions of unseen cell lines with high precision enable automatic generation of training data, which is used to train the model together with parts of the previously used annotated training data. We used U-Net-based model, and three consecutive focal planes from brightfield image z-stacks. We trained the model initially with PC-3 cell line, and used LNCaP, BT-474 and 22Rv1 cell lines as target domains for domain adaptation. Highest improvement in accuracy was achieved for 22Rv1 cells. F 1 -score after supervised training was only 0.65, but after unsupervised domain adaptation we achieved a score of 0.84. Mean accuracy for target domains was 0.87, with mean improvement of 16 percent. Conclusions: With our method for generalized cell detection, we can train a model that accurately detects different cell lines from brightfield images. A new cell line can be introduced to the model without a single manual annotation, and after iterative domain adaptation the model is ready to detect these cells with high accuracy.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, Tampere University of Applied Sciences, University of Eastern Finland
Contributors: Liimatainen, K., Kananen, L., Latonen, L., Ruusuvuori, P.
Publication date: 15 Feb 2019
Peer-reviewed: Yes

Publication information

Journal: BMC Bioinformatics
Volume: 20
Issue number: 1
Article number: 80
ISSN (Print): 1471-2105
Ratings: 
  • Scopus rating (2019): SJR 1.626 SNIP 1.156
Original language: English
ASJC Scopus subject areas: Structural Biology, Biochemistry, Molecular Biology, Computer Science Applications, Applied Mathematics
Keywords: Brightfield, Cell detection, Deep learning, Semi-supervised learning, Unsupervised domain adaptation
Electronic versions: 

Bibliographical note

DUPL=47150514

Source: Scopus
Source ID: 85061610929

Research output: Contribution to journalArticleScientificpeer-review

Challenges and recommended practices for software architecting in global software development

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

General information

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

Publication information

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

Research output: Contribution to journalArticleScientificpeer-review

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): 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

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): 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

Uses and Gratifications of Pokémon Go: Why do People Play Mobile Location-Based Augmented Reality Games?

In recent years, augmented reality games (ARGs) such as Pokémon Go have become increasingly popular. These games not only afford a novel gaming experience but also have the potential to alter how players view their physical realities. In addition to the common experiences and gratifications people derive from games, (location-based) ARGs can afford, for example outdoor adventures, communal activities, and health benefits, but also create problems stemming from, for example privacy concerns and poor usability. This raises some important research questions as to what drives people to use these new applications, and why they may be willing to spend money on the content sold within them. In this study, we investigate the various gratifications people derive from ARGs (Pokémon Go) and the relationship of these gratifications with the players’ intentions to continue playing and spending money on them. We employ data drawn from players of Pokémon Go (N = 1190) gathered through an online survey. The results indicate that game enjoyment, outdoor activity, ease of use, challenge, and nostalgia are positively associated with intentions to reuse (ITR), meanwhile outdoor activity, challenge, competition, socializing, nostalgia and ITR are associated with in-app purchase intentions (IPI). In contrast with our expectations, privacy concerns or trendiness were not associated with reuse intentions or IPI.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Gamification Group, George Mason University, University of Turku School of Cultural Production and Landscape Studies
Contributors: Hamari, J., Malik, A., Koski, J., Johri, A.
Publication date: 2019
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: International Journal of Human-Computer Interaction
Volume: 35
Issue number: 9
ISSN (Print): 1044-7318
Ratings: 
  • Scopus rating (2019): SJR 0.52 SNIP 1.536
Original language: English
ASJC Scopus subject areas: Human Factors and Ergonomics, Human-Computer Interaction, Computer Science Applications
Keywords: Augmented reality, freemium, gamification, location-based games, Uses and Gratifications
Source: Scopus
Source ID: 85050562939

Research output: Contribution to journalArticleScientificpeer-review

Customized dimensional analysis conceptual modelling framework for design optimization—a case study on the cross-flow micro turbine model

Dimensional Analysis Conceptual Modelling (DACM) is a framework used for conceptual modelling and simulation in system and product designs. The framework is based on cause–effect analysis between variables and functions in a problem. This article presents an approach that mobilizes concepts from the DACM framework to assist solve high-dimensional expensive optimization problems with lower computational costs. The latter fundamentally utilizes theories and concepts from well-practised dimensional analysis, functional modelling and bond graphing. Statistical design-of-experiments theory is also utilized in the framework to measure impact levels of variables towards the objective. Simplifying as well as decomposing followed by optimization of expensive problems are the focuses of the article. To illustrate the approach, a case study on the performance optimization of a cross-flow micro hydro turbine is presented. The customized DACM framework assisted optimization approach converges faster and returns better results than the one without. A single-step simplification approach is employed in the case study and it returns a better average optimization result with about only one fifth of the function evaluations compared to optimization using the original model.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mechanical Engineering and Industrial Systems, Research area: Manufacturing and Automation, University of Stavanger, Simon Fraser University
Contributors: Woldemariam, E. T., Coatanéa, E., Wang, G. G., Lemu, H. G., Wu, D.
Pages: 1168-1184
Publication date: 2019
Peer-reviewed: Yes
Early online date: 2018

Publication information

Journal: Engineering Optimization
Volume: 51
Issue number: 7
ISSN (Print): 0305-215X
Ratings: 
  • Scopus rating (2019): SJR 0.636 SNIP 1.294
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Management Science and Operations Research, Control and Optimization, Industrial and Manufacturing Engineering, Applied Mathematics
Keywords: Causality analysis, conceptual modelling, DACM assisted optimization, high-dimensional optimization, micro cross-flow turbine
Source: Scopus
Source ID: 85054818014

Research output: Contribution to journalArticleScientificpeer-review

Measuring stem diameters with TLS in boreal forests by complementary fitting procedure

Point clouds generated by terrestrial laser scanners (TLS) have enabled new ways to measure stem diameters. A common method for diameter calculation is to fit cylindrical or circular shapes into the TLS point cloud, which can be based either on a single scan or a co-registered combination of several scans. However, as various defects in the point cloud may affect the final diameter results, we propose an automatized processing chain which takes advantage of complementing steps. Processing consists of two fitting phases and an additional taper curve calculation to define the final diameter measurements. First, stems are detected from co-registered data of several scans using surface normals and cylinder fitting. This provides a robust framework for localizing the stems and estimating diameters at various heights. Then, guided by the cylinders and their indicative diameters, another fitting round is performed by cutting the stems into thin horizontal slices and reassessing their diameters by circular shape. For each slice, the quality of the cylinder-modelled diameter is evaluated first with co-registered data and if it is found to be deficient, potentially due to modelling defects or co-registration errors, diameter is detected through single scans. Finally, slice diameters are applied to construct a spline-based taper curve model for each tree, which is used to calculate the final stem dimensions. This methodology was tested in southern Finland using a set of 505 trees. At the breast height level (1.3 m), the results indicate 5.2 mm mean difference (3.2%), −0.4 mm bias (-0.3%) and 7.3 mm root mean squared error (4.4%) to reference measurements, and at the height of 6.0 m, respective values are 6.5 mm (3.6%), +1.6 mm (0.9%) and 8.4 mm (4.8%). These values are smaller compared to most of the corresponding contemporary studies, and outperform the initial cylinder models. This indicates that the applied processing chain is capable of producing relatively accurate diameter measurements, which can, at the cost of computational heaviness, remove various defects and improve the modelling results.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Natural Resources Institute Finland (Luke)
Contributors: Pitkänen, T. P., Raumonen, P., Kangas, A.
Number of pages: 13
Pages: 294-306
Publication date: 2019
Peer-reviewed: Yes
Early online date: 8 Dec 2018

Publication information

Journal: ISPRS Journal of Photogrammetry and Remote Sensing
Volume: 147
ISSN (Print): 0924-2716
Ratings: 
  • Scopus rating (2019): SJR 3.122 SNIP 2.881
Original language: English
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics, Engineering (miscellaneous), Computer Science Applications, Computers in Earth Sciences
Keywords: Circle fitting, Cylinder fitting, Stem extraction, Taper curve, Terrestrial laser scanning
Electronic versions: 
Source: Scopus
Source ID: 85057752987

Research output: Contribution to journalArticleScientificpeer-review

Modeling mass transfer in fracture flows with the time domain-random walk method

The time domain-random walk method was developed further for simulating mass transfer in fracture flows together with matrix diffusion in surrounding porous media. Specifically, a time domain-random walk scheme was developed for numerically approximating solutions of the advection-diffusion equation when the diffusion coefficient exhibits significant spatial variation or even discontinuities. The proposed scheme relies on second-order accurate, central-difference approximations of the advective and diffusive fluxes. The scheme was verified by comparing simulated results against analytical solutions in flow configurations involving a rectangular channel connected on one side with a porous matrix. Simulations with several flow rates, diffusion coefficients, and matrix porosities indicate good agreement between the numerical approximations and analytical solutions.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Physics, Geological Survey of Finland, University of Helsinki, University of Jyvaskyla
Contributors: Kuva, J., Voutilainen, M., Mattila, K.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: COMPUTATIONAL GEOSCIENCES
ISSN (Print): 1420-0597
Ratings: 
  • Scopus rating (2019): SJR 0.823 SNIP 1.424
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computers in Earth Sciences, Computational Theory and Mathematics, Computational Mathematics
Keywords: Advection, Breakthrough curve, Matrix diffusion, Porous media, Simulation, Solute transport
Source: Scopus
Source ID: 85069698468

Research output: Contribution to journalArticleScientificpeer-review

Quality and Capacity Analysis of Molecular Communications in Bacterial Synthetic Logic Circuits

Synthetic logic circuits have been proposed as potential solutions for theranostics of biotechnological problems. One proposed model is the engineering of bacteria cells to create logic gates, and the communication between the bacteria populations will enable the circuit operation. In this paper, we analyse the quality of bacteria-based synthetic logic circuit through molecular communications that represent communication along a bus between three gates. In the bacteria-based synthetic logic circuit, the system receives environmental signals as molecular inputs and will process this information through a cascade of synthetic logic gates and free diffusion channels. We analyse the performance of this circuit by evaluating its quality and its relationship to the channel capacity of the molecular communications links that interconnect the bacteria populations. Our results show the effect of the molecular environmental delay and molecular amplitude differences over both the channel capacity and circuit quality. Furthermore, based on these metrics we also obtain an optimum region for the circuit operation resulting in an accuracy of 80&#x0025; for specific conditions. These results show that the performance of synthetic biology circuits can be evaluated through molecular communications, and lays the groundwork for combined systems that can contribute to future biomedical and biotechnology applications.

General information

Publication status: Accepted/In press
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Waterford Institute of Technology
Contributors: Martins, D. P., Barros, M. T., Balasubramaniam, S.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Nanobioscience
ISSN (Print): 1536-1241
Ratings: 
  • Scopus rating (2019): SJR 0.62 SNIP 1.01
Original language: English
ASJC Scopus subject areas: Biotechnology, Bioengineering, Medicine (miscellaneous), Biomedical Engineering, Pharmaceutical Science, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Engineered bacteria, Logic circuits, Logic gates, Microorganisms, Molecular communication (telecommunication), Molecular communications, Sensors, Sociology, Statistics, Synthetic logic circuits
Source: Scopus
Source ID: 85070392121

Research output: Contribution to journalArticleScientificpeer-review

DNA Molecular Storage System: Transferring Digitally Encoded Information through Bacterial Nanonetworks

Since the birth of computer and networks, fuelled by pervasive computing, Internet of Things and ubiquitous connectivity, the amount of data stored and transmitted has exponentially grown through the years. Due to this demand, new storage solutions are needed. One promising media is the DNA as it provides numerous advantages, which includes the ability to store dense information while achieving long-term reliability. However, the question as to how the data can be retrieved from a DNA-based archive, still remains. In this paper, we aim to address this question by proposing a new storage solution that relies on bacterial nanonetworks properties. Our solution allows digitally-encoded DNA to be stored into motility-restricted bacteria, which compose an archival architecture of clusters, and to be later retrieved by engineered motile bacteria, whenever reading operations are needed. We conducted extensive simulations, in order to determine the reliability of data retrieval from motility-restricted storage clusters, placed spatially at different locations. Aiming to assess the feasibility of our solution, we have also conducted wet lab experiments that show how bacteria nanonetworks can effectively retrieve a simple message, such as "Hello World", by conjugation with motility-restricted bacteria, and finally mobilize towards a target point for delivery.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Universita degli Studi di Padova, Italy, Örebro University, Waterford Institute of Technology
Contributors: Tavella, F., Giaretta, A., Dooley-Cullinane, T. M., Conti, M., Coffey, L., Balasubramaniam, S.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Emerging Topics in Computing
ISSN (Print): 2168-6750
Ratings: 
  • Scopus rating (2019): SJR 0.807 SNIP 1.764
Original language: English
ASJC Scopus subject areas: Computer Science (miscellaneous), Information Systems, Human-Computer Interaction, Computer Science Applications
Keywords: Bacterial Nanonetworks, Data Storage, DNA Encoding, Molecular Communications
Source: Scopus
Source ID: 85070665316

Research output: Contribution to journalArticleScientificpeer-review

Positioning and Location-Aware Communications for Modern Railways with 5G New Radio

Providing high-capacity radio connectivity for high-speed trains (HSTs) is one of the most important use cases of emerging fifth generation (5G) New Radio (NR) networks. In this article, we show that 5G NR technology can also facilitate high-accuracy continuous localization and tracking of HSTs. Furthermore, we describe and demonstrate how the NR network can utilize the continuous location information for efficient beam management and beamforming, as well as for downlink Doppler precompensation in the single-frequency network context. Additionally, with particular focus on millimeter-wave networks, novel concepts for low-latency inter-carrier interference (ICI) estimation and compensation, due to residual Doppler and oscillator phase noise, are described and demonstrated. The provided numerical results at 30 GHz operating band show that sub-meter positioning and sub-degree beam direction accuracies can be obtained with very high probabilities on the order of 95-99 percent. The results also show that the described Doppler precompensation and ICI estimation and cancellation methods substantially improve the throughput of the single-frequency HST network.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Nokia Bell Labs
Contributors: Talvitie, J., Levanen, T., Koivisto, M., Ihalainen, T., Pajukoski, K., Valkama, M.
Number of pages: 7
Pages: 24-30
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 57
Issue number: 9
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2019): SJR 4.025 SNIP 4.403
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering

Bibliographical note

EXT="Ihalainen, Tero"

Source: Scopus
Source ID: 85072768579

Research output: Contribution to journalArticleScientificpeer-review

Environmental and social sustainability–emergence of well-being in the built environment, assessment tools and real estate market implications

Well-being has emerged as the new ‘green’ for buildings thought to reward occupiers, property owners, developers and other concerned actors. The new assessment tools for well-being are seen as the next step of currently widely used ‘traditional’ sustainability tools. However, a lack of knowledge globally about these tools, their compatibility and general adoption in the market due to the newness of the topic inspired this study. In the research, we aim at developing a deeper understanding of the well-being and social sustainability perspective as an innovation in relation to the built environment. The study consists of a literature review, a desktop study of sustainability and well-being rating tools and a qualitative interview data-based research on stakeholders’ position regarding the WELL-certificate adoption in the market. Lastly, the conclusions are drawn based on the results of empirical and desktop study. The results of this research benefit the scientific community by providing a better understanding of the well-being approach in the market and points out the areas of interest for further research. Practitioners can benefit from a deeper understanding of market adoption of well-being assessment tools and the development of sustainability concept in the built environment.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Civil Engineering, Research group: Responsible Construction, Aalto University, University of Melbourne, Finnish University Properties, Ltd
Contributors: Danivska, V., Heywood, C., Christersson, M., Zhang, E., Nenonen, S.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Intelligent Buildings International
ISSN (Print): 1750-8975
Ratings: 
  • Scopus rating (2019): SJR 0.297 SNIP 0.723
Original language: English
ASJC Scopus subject areas: Building and Construction, Computer Science Applications
Keywords: assessment tools, building certification, Health and well-being, market acceptance, social sustainability

Bibliographical note

EXT="Danivska, Vitalija"

Source: Scopus
Source ID: 85074504857

Research output: Contribution to journalArticleScientificpeer-review

Characterization of the anisotropic deformation of the right ventricle during open heart surgery

Digital Image Correlation (DIC) was used for studying the anisotropic behavior of the thin walled right ventricle of the human heart. Strains measured with Speckle Tracking Echocardiography (STE) were compared with the DIC data. Both DIC and STE were used to measure longitudinal strains of the right ventricle in the beginning of an open-heart surgery as well as after the cardiopulmonary bypass. Based on the results, the maximum end-systolic strains obtained with the DIC and STE change similarly during the surgery with less than 10% difference. The difference is largely due to the errors in matching the longitudinal direction in the two methods, sensitivity of the measurement to the positioning of the virtual extensometer of in both STE and DIC, and physiological difference of the measurements as the DIC measures the top surface of the heart whereas the STE obtains the data from below. The anisotropy of the RV was measured using full field principal strains acquired from the DIC displacement fields. The full field principal strains cover the entire region of interest instead of just two points as the virtual extensometer approach used by the STE. The principal strains are not direction dependent measures, and therefore are more independent of the anatomy of the patient and the exact positioning of the virtual strain gage or the STE probe. The results show that the longitudinal strains alone are not enough to fully characterize the behavior of the heart, as the deformation of the heart can be very anisotropic, and the anisotropy changes during the surgery, and from patient to patient.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Materials Science and Environmental Engineering, Research group: Materials Characterization, Hospital Heart Center, Tampere University
Contributors: Soltani, A., Lahti, J., Järvelä, K., Laurikka, J., Kuokkala, V. T., Hokka, M.
Number of pages: 12
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: COMPUTER METHODS IN BIOMECHANICS AND BIOMEDICAL ENGINEERING
ISSN (Print): 1025-5842
Ratings: 
  • Scopus rating (2019): SJR 0.451 SNIP 0.695
Original language: English
ASJC Scopus subject areas: Bioengineering, Biomedical Engineering, Human-Computer Interaction, Computer Science Applications
Keywords: anisotropy, biomaterial characterization, deformation, digital image correlation, heart muscle, Human biomechanics, motion

Bibliographical note

dupl=51243005

Source: Scopus
Source ID: 85076903988

Research output: Contribution to journalArticleScientificpeer-review

Emptiness problems for distributed automata

We investigate the decidability of the emptiness problem for three classes of distributed automata. These devices operate on finite directed graphs, acting as networks of identical finite-state machines that communicate in an infinite sequence of synchronous rounds. The problem is shown to be decidable in LOGSPACE for a class of forgetful automata, where the nodes see the messages received from their neighbors but cannot remember their own state. When restricted to the appropriate families of graphs, these forgetful automata are equivalent to classical finite word automata, but strictly more expressive than finite tree automata. On the other hand, we also show that the emptiness problem is undecidable in general. This already holds for two heavily restricted classes of distributed automata: those that reject immediately if they receive more than one message per round, and those whose state diagram must be acyclic except for self-loops. Additionally, to demonstrate the flexibility of distributed automata in simulating different models of computation, we provide a characterization of constraint satisfaction problems by identifying a class of automata with exactly the same computational power.

General information

Publication status: E-pub ahead of print
MoE publication type: A1 Journal article-refereed
Organisations: Computing Sciences, Helsinki University, UPEM
Contributors: Kuusisto, A., Reiter, F.
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Information and Computation
Article number: 104503
ISSN (Print): 0890-5401
Ratings: 
  • Scopus rating (2019): SJR 0.573 SNIP 1.203
Original language: English
ASJC Scopus subject areas: Theoretical Computer Science, Information Systems, Computer Science Applications, Computational Theory and Mathematics
Keywords: Distributed computing, Emptiness problem, Finite automata
Source: Scopus
Source ID: 85076991997

Research output: Contribution to journalArticleScientificpeer-review

Experimental analysis on the turning of aluminum alloy 7075 based on Taguchi method and artificial neural network

This paper mainly aims to disclose the effects of cutting conditions on the turning of aluminum alloy 7075 (AA7075). First, the artificial neural network (ANN) was programmed to investigate how cutting parameters, namely cutting speed, feed rate and depth of cut, affect the surface roughness of AA7075. Then, the taguchi method was introduced to design an L27 orthogonal array, in which each cutting parameter is considered on three levels. The results of orthogonal analysis were used to train the ANN called backpropagation neural network (BPNN) on MATLAB. The trained network was applied to predict the surface roughness of AA7075 through MATLAB simulation. Meanwhile, an experiment was conducted under the same conditions. The experimental results were found consistent with the simulation data, indicating that the BPNN is suitable for simulation the turning of AA7075. It is also learned that the cutting speed has the greatest impact on surface roughness; the surface roughness is negeatively correlated with feed rate; the negative correlation is positively mediated by the cutting speed.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Materials Science and Environmental Engineering, Manipal Academy of Higher Education, Dubai Campus
Contributors: Joshy, A., Dsouza, R., Muthirulan, V., Sachidananda, K. H.
Number of pages: 9
Pages: 429-437
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: Journal Europeen des Systemes Automatises
Volume: 52
Issue number: 5
ISSN (Print): 1269-6935
Ratings: 
  • Scopus rating (2019): SJR 0.177 SNIP 0.501
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Industrial and Manufacturing Engineering, Electrical and Electronic Engineering
Keywords: Artificial neural network (ANN), Cutting speed, Depth of cut, Feed rate, Machining, Surface roughness, Taguchi method, Turning
Source: Scopus
Source ID: 85077879334

Research output: Contribution to journalArticleScientificpeer-review

5G-U: Conceptualizing Integrated Utilization of Licensed and Unlicensed Spectrum for Future IoT

IoT applications constitute one of the fastest developing areas in today's technology and at the same time pose the most demanding challenges for the respective radio access network design. While the initial studies in IoT were focused primarily on scaling the existing radio solutions for higher numbers of small-data and low-cost sensors, the current developments aim at supporting wearable augmented/virtual reality platforms, moving industrial robots, driving (semi-)autonomous vehicles, and flying drones, which produce large amounts of data. To satisfy these rapidly growing performance demands, the 5G-grade IoT is envisioned to increasingly employ millimeter-wave (mmWave) spectrum, where wider bandwidths promise to enable higher data rates and low-latency communication. While the mainstream trend in mmWave-based IoT is to rely on licensed bands around 28 GHz or leverage unlicensed bands at 60 GHz, in this work we introduce a conceptual vision for the integrated use of these frequencies within a single radio access system named 5G over unlicensed spectrum or 5G-U. We study the performance of 5G-U in supporting stringent IoT use cases, discuss and compare the alternative strategies for spectrum management in 5G-U, and demonstrate that a harmonized utilization of licensed and unlicensed bands provides notable performance improvements in both device-centric and network-centric metrics. Finally, we offer useful guidelines for future implementations of 5G-U and detail its potential applications in the area of advanced IoT services.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electrical Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Research group: Wireless Communications and Positioning, King’s College London
Contributors: Lu, X., Petrov, V., Moltchanov, D., Andreev, S., Mahmoodi, T., Dohler, M.
Number of pages: 7
Pages: 92-98
Publication date: 2019
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 57
Issue number: 7
Article number: 8722595
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2019): SJR 4.025 SNIP 4.403
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85067057054

Research output: Contribution to journalArticleScientificpeer-review

SCIP: a single-cell image processor toolbox

Summary: Each cell is a phenotypically unique individual that is influenced by internal and external processes, operating in parallel. To characterize the dynamics of cellular processes one needs to observe many individual cells from multiple points of view and over time, so as to identify commonalities and variability. With this aim, we engineered a software, 'SCIP', to analyze multi-modal, multi-process, time-lapse microscopy morphological and functional images. SCIP is capable of automatic and/or manually corrected segmentation of cells and lineages, automatic alignment of different microscopy channels, as well as detect, count and characterize fluorescent spots (such as RNA tagged by MS2-GFP), nucleoids, Z rings, Min system, inclusion bodies, undefined structures, etc. The results can be exported into *mat files and all results can be jointly analyzed, to allow studying not only each feature and process individually, but also find potential relationships. While we exemplify its use on Escherichia coli, many of its functionalities are expected to be of use in analyzing other prokaryotes and eukaryotic cells as well. We expect SCIP to facilitate the finding of relationships between cellular processes, from small-scale (e.g. gene expression) to large-scale (e.g. cell division), in single cells and cell lineages. Availability and implementation: http://www.ca3-uninova.org/project_scip. Supplementary information: Supplementary data are available at Bioinformatics online.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Campus FCT-UNL
Contributors: Martins, L., Neeli-Venkata, R., Oliveira, S. M., Häkkinen, A., Ribeiro, A. S., Fonseca, J. M.
Number of pages: 3
Pages: 4318-4320
Publication date: 15 Dec 2018
Peer-reviewed: Yes

Publication information

Journal: Bioinformatics
Volume: 34
Issue number: 24
ISSN (Print): 1367-4803
Ratings: 
  • Scopus rating (2018): CiteScore 5.94 SJR 4.549 SNIP 1.908
Original language: English
ASJC Scopus subject areas: Statistics and Probability, Biochemistry, Molecular Biology, Computer Science Applications, Computational Theory and Mathematics, Computational Mathematics

Research output: Contribution to journalArticleScientificpeer-review

A Portable Microscale Cell Culture System with Indirect Temperature Control

A physiologically relevant environment is essential for successful long-term cell culturing in vitro. Precise control of temperature, one of the most crucial environmental parameters in cell cultures, increases the fidelity and repeatability of the experiments. Unfortunately, direct temperature measurement can interfere with the cultures or prevent imaging of the cells. Furthermore, the assessment of dynamic temperature variations in the cell culture area is challenging with the methods traditionally used for measuring temperature in cell culture systems. To overcome these challenges, we integrated a microscale cell culture environment together with live-cell imaging and a precise local temperature control that is based on an indirect measurement. The control method uses a remote temperature measurement and a mathematical model for estimating temperature at the desired area. The system maintained the temperature at 37±0.3 °C for more than 4 days. We also showed that the system precisely controls the culture temperature during temperature transients and compensates for the disturbance when changing the cell cultivation medium, and presented the portability of the heating system. Finally, we demonstrated a successful long-term culturing of human induced stem cell–derived beating cardiomyocytes, and analyzed their beating rates at different temperatures.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Computational Biophysics and Imaging Group, Research group: Sensor Technology and Biomeasurements (STB), Research group: Micro and Nanosystems Research Group, Tampere University Hospital
Contributors: Mäki, A. J., Verho, J., Kreutzer, J., Ryynänen, T., Rajan, D., Pekkanen-Mattila, M., Ahola, A., Hyttinen, J., Aalto-Setälä, K., Lekkala, J., Kallio, P.
Pages: 566-579
Publication date: 1 Dec 2018
Peer-reviewed: Yes
Early online date: 1 Apr 2018

Publication information

Journal: SLAS Technology
Volume: 23
Issue number: 6
ISSN (Print): 2472-6303
Ratings: 
  • Scopus rating (2018): CiteScore 1.96 SJR 0.511 SNIP 0.523
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Medical Laboratory Technology
Keywords: cell culture, feedback control, microfluidics, modeling, temperature
Source: Scopus
Source ID: 85046801632

Research output: Contribution to journalArticleScientificpeer-review

Organizing for openness: six models for developer involvement in hybrid OSS projects

This article examines organization and governance of commercially influenced Open Source Software development communities by presenting a multiple-case study of six contemporary, hybrid OSS projects. The findings provide in-depth understanding on how to design the participatory nature of the software development process, while understanding the factors that influence the delicate balance of openness, motivations, and governance. The results lay ground for further research on how to organize and manage developer communities where needs of the stakeholders are competing, yet complementary.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, University of Helsinki, Lappeenranta University of Technology
Contributors: Mäenpää, H., Mäkinen, S., Kilamo, T., Mikkonen, T., Männistö, T., Ritala, P.
Publication date: 1 Dec 2018
Peer-reviewed: Yes

Publication information

Journal: Journal of Internet Services and Applications
Volume: 9
Issue number: 1
Article number: 17
ISSN (Print): 1867-4828
Ratings: 
  • Scopus rating (2018): CiteScore 3.24 SJR 0.397 SNIP 1.602
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications
Keywords: Community management, Governance, Hybrid open source, Open source, Software development process
Electronic versions: 
Source: Scopus
Source ID: 85051727092

Research output: Contribution to journalArticleScientificpeer-review

Active scanner control on paper machines

The cross-directional (CD) basis weight control on paper machines is improved by optimizing the path of the scanning measurement. The optimal path results from an LQG problem and depends on how the uncertainty of the present estimate of the basis weight and the intensity of process noise vary in CD. These factors are assessed by how accurately the CD basis weight estimate predicts the measured optical transmittance with a linear adaptive model on synchronized basis weight and transmittance data. Simulations on optimized scanner path in disturbance scenarios are presented, and the practical implementation of scanner control is discussed.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering
Contributors: Raunio, J., Ritala, R.
Number of pages: 17
Pages: 74-90
Publication date: 1 Dec 2018
Peer-reviewed: Yes

Publication information

Journal: Journal of Process Control
Volume: 72
ISSN (Print): 0959-1524
Ratings: 
  • Scopus rating (2018): CiteScore 4.05 SJR 0.967 SNIP 2.027
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Modelling and Simulation, Computer Science Applications, Industrial and Manufacturing Engineering
Keywords: basis weight, linear-quadratic-Gaussian, optimal measurement, paper machine, scanner, transmittance, variance estimation, web-wide measurement
Source: Scopus
Source ID: 85056176314

Research output: Contribution to journalArticleScientificpeer-review

Empirical Effects of Dynamic Human-Body Blockage in 60 GHz Communications

The millimeter-wave (mmWave) bands and other high frequencies above 6 GHz have emerged as a central component of fifth generation cellular standards to deliver high data rates and ultra-low latency. A key challenge in these bands is blockage from obstacles, including the human body. In addition to the reduced coverage, blockage can result in highly intermittent links where the signal quality varies significantly with motion of obstacles in the environment. The blockages have widespread consequences throughout the protocol stack including beam tracking, link adaptation, cell selection, handover, and congestion control. Accurately modeling these blockage dynamics is therefore critical for the development and evaluation of potential mmWave systems. In this work, we present a novel spatial dynamic channel sounding system based on phased array transmitters and receivers operating at 60 GHz. Importantly, the sounder can measure multiple directions rapidly at high speed to provide detailed spatial dynamic measurements of complex scenarios. The system is demonstrated in an indoor home entertainment type setting with multiple moving blockers. Preliminary results are presented on analyzing this data with a discussion of the open issues toward developing statistical dynamic models.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, NYU Tandon School of Engineering, Peoples’ Friendship University of Russia
Contributors: Slezak, C., Semkin, V., Andreev, S., Koucheryavy, Y., Rangan, S.
Number of pages: 7
Pages: 60-66
Publication date: 1 Dec 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 56
Issue number: 12
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2018): CiteScore 11.27 SJR 2.373 SNIP 4.903
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85058494833

Research output: Contribution to journalArticleScientificpeer-review

Benefits of Positioning-Aided Communication Technology in High-Frequency Industrial IoT

The future of industrial applications is shaped by intelligent moving IoT devices, such as flying drones, advanced factory robots, and connected vehicles, which may operate (semi-)autonomously. In these challenging scenarios, dynamic radio connectivity at high frequencies, augmented with timely positioning-related information, becomes instrumental to improve communication performance and facilitate efficient computation offloading. Our work reviews the main research challenges and reveals open implementation gaps in IIoT applications that rely on location awareness and multi-connectivity in super high and extremely high frequency bands. It further conducts a rigorous numerical investigation to confirm the potential of precise device localization in the emerging IIoT systems. We focus on positioning- aided benefits made available to multi-connectivity IIoT device operation at 28 GHz, which notably improve data transfer rates, communication latency, and the extent of control overhead.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Univ of Oulu, Huawei Technologies Oy (Finland). Co. Ltd.
Contributors: Lohan, E. S., Koivisto, M., Galinina, O., Andreev, S., Tölli, A., Destino, G., Costa, M., Leppänen, K., Koucheryavy, Y., Valkama, M.
Number of pages: 7
Pages: 142-148
Publication date: 14 Nov 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 56
Issue number: 12
Article number: 8535084
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2018): CiteScore 11.27 SJR 2.373 SNIP 4.903
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85056574017

Research output: Contribution to journalArticleScientificpeer-review

Chromatographic studies of n-Propyl Propionate: Adsorption equilibrium, modelling and uncertainties determination

The n-Propyl Propionate (ProPro) is a compound that has several possible industrial applications. However, the current production route of this component presents several problems, such as the downstream purification. In this way, chromatographic separation could be an alternative solution to the downstream purification. In this work experimental studies of the ProPro reaction system separation in a chromatographic fixed bed unit packed with Amberlyst 46 were performed. The adsorption equilibrium isotherms and the corresponding Langmuir model parameters were determined. A phenomenological model to represent the process was developed and validated through the experimental data. Meanwhile, it is proposed the characterization of the uncertainties of all steps and its extension to the model prediction, which allowed to estimate the model parameters with a reduced number of experiments, when compared with other reports in the literature; nevertheless, the final results lead to a statistically more reliable model.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering, Research group: Automation and Systems Theory, Universidade do Porto, Federal Univ. of Bahia
Contributors: Nogueira, I. B., Faria, R. P., Requião, R., Koivisto, H., Martins, M. A., Rodrigues, A. E., Loureiro, J. M., Ribeiro, A. M.
Number of pages: 12
Pages: 371-382
Publication date: 2 Nov 2018
Peer-reviewed: Yes

Publication information

Journal: Computers and Chemical Engineering
Volume: 119
ISSN (Print): 0098-1354
Ratings: 
  • Scopus rating (2018): CiteScore 3.98 SJR 0.932 SNIP 1.562
Original language: English
ASJC Scopus subject areas: Chemical Engineering(all), Computer Science Applications
Keywords: Adsorption equilibrium isotherms, Confidence region, Fixed bed adsorptive unit, n-Propyl Propionate, Particle swarm optimization
Source: Scopus
Source ID: 85054180293

Research output: Contribution to journalArticleScientificpeer-review

Computation of Dynamic Polarizabilities and van der Waals Coefficients from Path-Integral Monte Carlo

We demonstrate computation of total dynamic multipole polarizabilities using path-integral Monte Carlo method (PIMC). The PIMC approach enables accurate thermal and nonadiabatic mixing of electronic, rotational, and vibrational degrees of freedom. Therefore, we can study the thermal effects, or lack thereof, in the full multipole spectra of the chosen one- and two-electron systems: H, Ps, He, Ps2, H2, and HD+. We first compute multipole-multipole correlation functions up to octupole order in imaginary time. The real-domain spectral function is then obtained by analytical continuation with the maximum entropy method. In general, sharpness of the active spectra is limited, but the obtained off-resonant polarizabilities are in good agreement with the existing literature. Several weak and strong thermal effects are observed. Furthermore, the polarizabilities of Ps2 and some higher multipole and higher frequency data have not been published before. In addition, we compute isotropic dispersion coefficients C6, C8, and C10 between pairs of species using the simplified Casimir-Polder formulas.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Physics, Research group: Electronic Structure Theory, Research area: Computational Physics
Contributors: Tiihonen, J., Kylänpää, I., Rantala, T. T.
Number of pages: 14
Pages: 5750-5763
Publication date: 2 Oct 2018
Peer-reviewed: Yes

Publication information

Journal: Journal of Chemical Theory and Computation
Volume: 14
ISSN (Print): 1549-9618
Ratings: 
  • Scopus rating (2018): CiteScore 5.7 SJR 2.236 SNIP 1.585
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Physical and Theoretical Chemistry
Electronic versions: 
URLs: 
Source: Scopus
Source ID: 85055154322

Research output: Contribution to journalArticleScientificpeer-review

Focus model for metric depth estimation in standard plenoptic cameras

In recent years, a lot of efforts have been devoted to the problem of depth estimation from lightfield images captured by standard plenoptic cameras. However, most of the metric depth estimation methods in the state-of-the-art leverage pixel disparity only. In this paper, we tackle the problem of focus-based metric depth estimation in standard plenoptic cameras. For this purpose we propose a closed-form model that relates the refocusing parameter with the focus distance of a plenoptic camera in order to allow for metric depth estimation. Based on the proposed model, we develop a calibration procedure that allows finding the parameters of the model. Using measurements of a time-of-flight sensor as ground-truth, experimental validation in a distance range of 0.2–1.6 m shows that focus-based depth estimation is feasible with a root-mean-squared error of less than 5 cm.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Universidad Industrial de Santander, Universidad Antonio Nariño
Contributors: Pertuz, S., Pulido-Herrera, E., Kämäräinen, J.
Number of pages: 10
Pages: 38-47
Publication date: 1 Oct 2018
Peer-reviewed: Yes

Publication information

Journal: ISPRS Journal of Photogrammetry and Remote Sensing
Volume: 144
ISSN (Print): 0924-2716
Ratings: 
  • Scopus rating (2018): CiteScore 8.64 SJR 2.979 SNIP 3.205
Original language: English
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics, Engineering (miscellaneous), Computer Science Applications, Computers in Earth Sciences
Keywords: Calibration, Depth estimation, Focus, Lightfield, Plenoptic camera
Source: Scopus
Source ID: 85049523458

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 6.9 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

Breaking the limits in urban video monitoring: Massive crowd sourced surveillance over vehicles

Contemporary urban environments are in prompt need of the means for intelligent decision- making, where a crucial role belongs to smart video surveillance systems. While existing deployments of stationary monitoring cameras already deliver notable societal benefits, the proposed concept of massive video surveillance over connected vehicles that we contribute in this article may further augment these important capabilities. We therefore introduce the envisioned system concept, discuss its implementation, outline the high-level architecture, and identify major data flows, while also offering insights into the corresponding design and deployment aspects. Our conducted case study confirms the potential of the described crowd sourced vehicular system to effectively complement and eventually surpass even the best of today's static video surveillance setups. We expect that our proposal will become of value and integrate seamlessly into the future Internetof- Things landscape, thus enabling a plethora of advanced urban applications.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Electrical Engineering Department, University of California, Los Angeles (UCLA), National Research University Higher School of Economics
Contributors: Petrov, V., Andreev, S., Gerla, M., Koucheryavy, Y.
Number of pages: 9
Pages: 104-112
Publication date: 1 Oct 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 25
Issue number: 5
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2018): CiteScore 11.8 SJR 2.352 SNIP 4.212
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85054226112

Research output: Contribution to journalArticleScientificpeer-review

Molecular Communications Pulse-based Jamming Model for Bacterial Biofilm Suppression

Studies have recently shown that the bacteria survivability within biofilms is responsible for the emergence of superbugs. The combat of bacterial infections, without enhancing its resistance to antibiotics, includes the use of nanoparticles to quench the quorum sensing of these biofilm-forming bacteria. Several sequential and parallel multi-stage communication processes are involved in the formation of biofilms. In this paper, we use proteomic data from a wet lab experiment to identify the communication channels that are vital to these processes.We also identified the main proteins from each channel and propose the use of jamming signals from synthetically engineered bacteria to suppress the production of those proteins. This biocompatible technique is based on synthetic biology and enables the inhibition of biofilm formation. We analyse the communications performance of the jamming process, by evaluating the path loss for a number of conditions that include different engineered bacterial population sizes, distances between the populations and molecular signal power. Our results show that sufficient molecular pulsebased jamming signals are able to prevent the biofilm formation by creating lossy communications channels (almost -3 dB for certain scenarios). From these results, we define the main design parameters to develop a fully operational bacteria-based jamming system.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Waterford Institute of Technology, Kasetsart University
Contributors: Martins, D. P., Leetanasaksakul, K., Barros, M. T., Thamchaipenet, A., Donnelly, W., Balasubramaniam, S.
Number of pages: 12
Pages: 533-542
Publication date: Oct 2018
Peer-reviewed: Yes
Early online date: 19 Sep 2018

Publication information

Journal: IEEE Transactions on Nanobioscience
Volume: 17
Issue number: 4
ISSN (Print): 1536-1241
Ratings: 
  • Scopus rating (2018): CiteScore 2.23 SJR 0.541 SNIP 0.792
Original language: English
ASJC Scopus subject areas: Biotechnology, Bioengineering, Medicine (miscellaneous), Biomedical Engineering, Pharmaceutical Science, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Biofilm suppression, Communications systems, Jamming, Synthetic logic circuits
Source: Scopus
Source ID: 85053611196

Research output: Contribution to journalArticleScientificpeer-review

Comparative analysis of tissue reconstruction algorithms for 3D histology

Motivation: Digital pathology enables new approaches that expand beyond storage, visualization or analysis of histological samples in digital format. One novel opportunity is 3D histology, where a three-dimensional reconstruction of the sample is formed computationally based on serial tissue sections. This allows examining tissue architecture in 3D, for example, for diagnostic purposes. Importantly, 3D histology enables joint mapping of cellular morphology with spatially resolved omics data in the true 3D context of the tissue at microscopic resolution. Several algorithms have been proposed for the reconstruction task, but a quantitative comparison of their accuracy is lacking. Results: We developed a benchmarking framework to evaluate the accuracy of several free and commercial 3D reconstruction methods using two whole slide image datasets. The results provide a solid basis for further development and application of 3D histology algorithms and indicate that methods capable of compensating for local tissue deformation are superior to simpler approaches.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Mechanical Engineering and Industrial Systems, Signal Processing, Research group: Data-analytics and Optimization, Tampere University Hospital, Faculty of Medicine and Life Sciences, BioMediTech, Fimlab Laboratories Ltd, BioMediTech Institute
Contributors: Kartasalo, K., Latonen, L., Vihinen, J., Visakorpi, T., Nykter, M., Ruusuvuori, P.
Number of pages: 9
Pages: 3013-3021
Publication date: 1 Sep 2018
Peer-reviewed: Yes

Publication information

Journal: Bioinformatics
Volume: 34
Issue number: 17
ISSN (Print): 1367-4803
Ratings: 
  • Scopus rating (2018): CiteScore 5.94 SJR 4.549 SNIP 1.908
Original language: English
ASJC Scopus subject areas: Statistics and Probability, Biochemistry, Molecular Biology, Computer Science Applications, Computational Theory and Mathematics, Computational Mathematics
Electronic versions: 
Source: Scopus
Source ID: 85055091427

Research output: Contribution to journalArticleScientificpeer-review

Intellectual capital and bi-tools in private healthcare value creation

The demand for data-driven decision making in the healthcare sector has increased, not only on the clinical side, but also from the managerial perspective; this is especially true in the private healthcare sector. Utilisation of internal and external data requires certain capabilities, such as intellectual capital (IC), as different data sources (structural capital) and organisational competences (human capital) can become organisational value. We study the utilisation of business intelligence (BI) tools and IC dimensions in creating value in the Finnish private healthcare sector. IC components and a modified value creation capabilities model are used as a framework for considering data utilisation and BI tools' role in value creation. Our study includes private healthcare organisations in Finland and management and BI technology consulting representatives. Thematic interviews of key personnel responsible for BI were conducted to elucidate the value creation capabilities, IC components and BI tool utilisation in the Finnish private healthcare industry. Data-driven decision making is currently one of the most discussed topics in private healthcare sector organisations. By analysing the current data source utilisation and organisational competences in data utilisation, we gain a better understanding of IC and BI tool-enabled value creation in private healthcare organisations. The study's outcomes will provide valuable information and a deep understanding concerning the influence of BI tools and IC dimensions on value creation in private health care in Finland. In addition, it will provide insight into future-oriented value creation factors that can enable new business concepts for private healthcare companies. Advanced capability of data utilisation will increase the value creation ability in private healthcare sector companies. However, in addition to the technology and data, human capital or capability of BI tool utilisation and data-driven decision making are crucial.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Industrial and Information Management
Contributors: Ratia, M.
Number of pages: 12
Pages: 143-154
Publication date: 1 Sep 2018
Peer-reviewed: Yes

Publication information

Journal: Electronic Journal of Knowledge Management
Volume: 16
Issue number: 2
ISSN (Print): 1479-4411
Original language: English
ASJC Scopus subject areas: Management Information Systems, Management of Technology and Innovation, Computer Networks and Communications, Computer Science Applications
Keywords: business intelligence, external data sources, intellectual capital, Private healthcare, value creation
Electronic versions: 
Source: Scopus
Source ID: 85056996165

Research output: Contribution to journalArticleScientificpeer-review

Nocturnal Heart Rate Variability Spectrum Characterization in Preschool Children with Asthmatic Symptoms

Asthma is a chronic lung disease that usually develops during chilhood. Despite that symptoms can almost be controlled with medication, early diagnosis is desirable in order to reduce permanent airway obstruction risk. It has been suggested that abnormal parasympathetic nervous system (PSNS) activity might be closely related with the pathogenesis of asthma, and that this PSNS activity could be reflected in cardiac vagal control. In this work, an index to measure the spectral regularity of the high frequency (HF) component of heart rate variability (HRV) spectrum, named peakness (P), is proposed. Three different implementations of P, based on electrocardiogram (ECG) recordings, impedance pneumography (IP) recordings and a combination of both, were employed in the characterization of a group of pre-school children classified attending to their risk of developing asthma. Peakier componentswere observed in the HF band of those children classified as high-risk (p &lt; 0.005), who also presented reduced sympathvoagal balance. Results suggest that high-risk of developing asthma might be related with a lack of adaptability of PSNS.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Physiological Measurement Systems and Methods Group, University of Zaragoza, KU Leuven, University of Helsinki
Contributors: Milagro, J., Gil, E., Lazaro, J., Seppae, V. P., Malmberg, L. P., Pelkonen, A. S., Kotaniemi-Syrjanen, A., Makela, M., Viik, J., Bailon, R.
Pages: 1332-1340
Publication date: Sep 2018
Peer-reviewed: Yes
Early online date: 16 Nov 2017

Publication information

Journal: IEEE Journal of Biomedical and Health Informatics
Volume: 22
Issue number: 5
ISSN (Print): 2168-2194
Ratings: 
  • Scopus rating (2018): CiteScore 5.67 SJR 1.122 SNIP 2.524
Original language: English
ASJC Scopus subject areas: Biotechnology, Computer Science Applications, Electrical and Electronic Engineering, Health Information Management
Keywords: asthma, children, Electrocardiography, Heart rate variability, heart rate variability, Informatics, parasympathetic nervous system, peakness, Pediatrics, Pregnancy, Respiratory system, Signal to noise ratio
Source: Scopus
Source ID: 85035749268

Research output: Contribution to journalArticleScientificpeer-review

High surface quality welding of aluminum using adjustable ring-mode fiber laser

A method to improve penetration and stabilize the welding phenomenon at a high welding speed has been described through experimental and numerical investigations. Using a high power laser beam consisting of a center and a ring part, influences of shielding gas direction and flow rate, laser power density, and welding mode defined by variable intensity distribution have been clarified. The weld bead was evaluated in terms of width, height, shape and roughness. Dual-mode laser irradiation of center and ring power made it possible to stabilize the welding process. The center power helps to achieve sufficient deep penetration, while ring power ensures good temperature distribution. Good surface quality and deep penetration welding could be achieved with dual-mode welding, using low flow rate of shielding gas supplied from the backside direction.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mechanical Engineering and Industrial Systems, Okayama University, Corelase Oy
Contributors: Maina, M. R., Okamoto, Y., Okada, A., Närhi, M., Kangastupa, J., Vihinen, J.
Number of pages: 9
Pages: 180-188
Publication date: 1 Aug 2018
Peer-reviewed: Yes

Publication information

Journal: Journal of Materials Processing Technology
Volume: 258
ISSN (Print): 0924-0136
Ratings: 
  • Scopus rating (2018): CiteScore 5.08 SJR 1.719 SNIP 2.888
Original language: English
ASJC Scopus subject areas: Ceramics and Composites, Computer Science Applications, Metals and Alloys, Industrial and Manufacturing Engineering
Keywords: Adjustable ring-mode fiber laser, Aluminum, Laser welding, Shielding gas, Surface quality
Source: Scopus
Source ID: 85044959061

Research output: Contribution to journalArticleScientificpeer-review

Summarization of User-Generated Sports Video by Using Deep Action Recognition Features

Automatically generating a summary of sports video poses the challenge of detecting interesting moments, or highlights, of a game. Traditional sports video summarization methods leverage editing conventions of broadcast sports video that facilitate the extraction of high-level semantics. However, user-generated videos are not edited, and thus traditional methods are not suitable to generate a summary. In order to solve this problem, this work proposes a novel video summarization method that uses players' actions as a cue to determine the highlights of the original video. A deep neural network-based approach is used to extract two types of action-related features and to classify video segments into interesting or uninteresting parts. The proposed method can be applied to any sports in which games consist of a succession of actions. Especially, this work considers the case of Kendo (Japanese fencing) as an example of a sport to evaluate the proposed method. The method is trained using Kendo videos with ground truth labels that indicate the video highlights. The labels are provided by annotators possessing different experience with respect to Kendo to demonstrate how the proposed method adapts to different needs. The performance of the proposed method is compared with several combinations of different features, and the results show that it outperforms previous summarization methods.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, University of Tokyo, Osaka University, Graduate School of Information Science, Univ of Oulu
Contributors: Tejero-de-Pablos, A., Nakashima, Y., Sato, T., Yokoya, N., Linna, M., Rahtu, E.
Pages: 2000-2011
Publication date: Aug 2018
Peer-reviewed: Yes
Early online date: 15 Jan 2018

Publication information

Journal: IEEE Transactions on Multimedia
Volume: 20
Issue number: 8
ISSN (Print): 1520-9210
Ratings: 
  • Scopus rating (2018): CiteScore 7.41 SJR 1.222 SNIP 3.016
Original language: English
ASJC Scopus subject areas: Signal Processing, Media Technology, Computer Science Applications, Electrical and Electronic Engineering
Keywords: 3D convolutional neural networks, action recognition, Cameras, deep learning, Feature extraction, Games, Hidden Markov models, long short-term memory, Semantics, Sports video summarization, Three-dimensional displays, user-generated video
Source: Scopus
Source ID: 85041689127

Research output: Contribution to journalArticleScientificpeer-review

Wireless Communications for Optogenetics-Based Brain Stimulation: Present Technology and Future Challenges

The ability to decipher brain functions and understand the neuronal communication networking properties to develop innovative solutions to treat neurodegenerative diseases remains one of the biggest challenges in biomedicine. Since the early days, numerous solutions have been proposed for BMI, largely concentrating on the use of tethered electrodes that are inserted into the brain to either stimulate or suppress neural activities. In recent years, the field of optogenetics has provided a new alternative of utilizing light to stimulate genetically engineered neurons. While the original approach proposed the use of tethered optical cables inserted into the skull to transfer light into the brain for stimulation, numerous advances have been made to incorporate wireless technologies that will allow these devices to be attached to the skull or implanted in the brain. This article presents a review on the current technologies that have been proposed for different wireless optogenetics solutions, ranging from devices that are head mounted to miniature devices that can be embedded deep in the brain. We focus on a comparative analysis of the architecture and structure of the devices, the wireless technology used for signaling to the unit, as well as the energy consumption profile for each of the devices. Finally, the article presents future challenges to further miniaturize wireless optogenetic devices, concentrating specifically on the communication properties.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Waterford Institue of Technology, State University of New York
Contributors: Balasubramaniam, S., Wirdatmadja, S. A., Barros, M. T., Koucheryavy, Y., Stachowiak, M., Jornet, J. M.
Number of pages: 7
Pages: 218-224
Publication date: 1 Jul 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 56
Issue number: 7
Article number: 8419204
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2018): CiteScore 11.27 SJR 2.373 SNIP 4.903
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85051078230

Research output: Contribution to journalArticleScientificpeer-review

Effect of surfactant type and sonication energy on the electrical conductivity properties of nanocellulose-CNT nanocomposite films

We present a detailed study on the influence of sonication energy and surfactant type on the electrical conductivity of nanocellulose-carbon nanotube (NFC-CNT) nanocomposite films. The study was made using a minimum amount of processing steps, chemicals and materials, to optimize the conductivity properties of free-standing flexible nanocomposite films. In general, the NFC-CNT film preparation process is sensitive concerning the dispersing phase of CNTs into a solution with NFC. In our study, we used sonication to carry out the dispersing phase of processing in the presence of surfactant. In the final phase, the films were prepared from the dispersion using centrifugal cast molding. The solid films were analyzed regarding their electrical conductivity using a four-probe measuring technique. We also characterized how conductivity properties were enhanced when surfactant was removed from nanocomposite films; to our knowledge this has not been reported previously. The results of our study indicated that the optimization of the surfactant type clearly affected the formation of freestanding films. The effect of sonication energy was significant in terms of conductivity. Using a relatively low 16 wt. % concentration of multiwall carbon nanotubes we achieved the highest conductivity value of 8.4 S/cm for nanocellulose-CNT films ever published in the current literature. This was achieved by optimizing the surfactant type and sonication energy per dry mass. Additionally, to further increase the conductivity, we defined a preparation step to remove the used surfactant from the final nanocomposite structure.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Materials Science, Faculty of Biomedical Sciences and Engineering, VTT Technical Research Centre of Finland
Contributors: Siljander, S., Keinänen, P., Räty, A., Ramakrishnan, K. R., Tuukkanen, S., Kunnari, V., Harlin, A., Vuorinen, J., Kanerva, M.
Publication date: 20 Jun 2018
Peer-reviewed: Yes

Publication information

Journal: International Journal of Molecular Sciences
Volume: 19
Issue number: 6
Article number: 1819
ISSN (Print): 1661-6596
Ratings: 
  • Scopus rating (2018): CiteScore 4.32 SJR 1.312 SNIP 1.274
Original language: English
ASJC Scopus subject areas: Catalysis, Molecular Biology, Spectroscopy, Computer Science Applications, Physical and Theoretical Chemistry, Organic Chemistry, Inorganic Chemistry
Keywords: Carbon nanotubes, Conductivity, Nanocellulose, Nanocomposite, Surfactant
Electronic versions: 

Bibliographical note

INT=mol,"Räty, Anna"
EXT="Harlin, Ali"

Source: Scopus
Source ID: 85048936349

Research output: Contribution to journalArticleScientificpeer-review

Last Meter Indoor Terahertz Wireless Access: Performance Insights and Implementation Roadmap

The terahertz band, 0.1-10 THz, has sufficient resources not only to satisfy the 5G requirements of 10 Gb/s peak data rate but to enable a number of tempting rate-greedy applications. However, the terahertz band brings novel challenges, never addressed at lower frequencies. Among others, the scattering of terahertz waves from any object, including walls and furniture, and ultra-wideband highly directional links lead to fundamentally new propagation and interference structures. In this article, we review the recent progress in terahertz propagation modeling, and antenna and testbed designs, and propose a step-by-step roadmap for wireless terahertz Ethernet extension for indoor environments. As a side effect, the described concept provides a second life to the currently underutilized Ethernet infrastructure by using it as a universally available backbone. By applying real terahertz band propagation, reflection, and scattering measurements as well as ray-tracing simulations of a typical office, we analyze two representative scenarios at 300 GHz and 1.25 THz frequencies, illustrating that extremely high rates can be achieved with realistic system parameters at room scales.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, University of Oulu
Contributors: Petrov, V., Kokkoniemi, J., Moltchanov, D., Lehtomäki, J., Koucheryavy, Y., Juntti, M.
Number of pages: 8
Pages: 158-165
Publication date: 1 Jun 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 56
Issue number: 6
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2018): CiteScore 11.27 SJR 2.373 SNIP 4.903
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85048785161

Research output: Contribution to journalArticleScientificpeer-review

Caching-Aided Collaborative D2D Operation for Predictive Data Dissemination in Industrial IoT

Industrial automation deployments constitute challenging environments where moving IoT machines may produce high-definition video and other heavy sensor data during surveying and inspection operations. Transporting massive contents to the edge network infrastructure and then eventually to the remote human operator requires reliable and high-rate radio links supported by intelligent data caching and delivery mechanisms. In this work, we address the challenges of contents dissemination in characteristic factory automation scenarios by proposing to engage moving industrial machines as D2D caching helpers. With the goal of improving the reliability of high-rate mmWave data connections, we introduce alternative contents dissemination modes and then construct a novel mobility-aware methodology that helps develop predictive mode selection strategies based on the anticipated radio link conditions. We also conduct a thorough system-level evaluation of representative data dissemination strategies to confirm the benefits of predictive solutions that employ D2D-enabled collaborative caching at the wireless edge to lower contents delivery latency and improve data acquisition reliability.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering
Contributors: Orsino, A., Kovalchukov, R., Samuylov, A., Moltchanov, D., Andreev, S., Koucheryavy, Y., Valkama, M.
Number of pages: 8
Pages: 50-57
Publication date: 1 Jun 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 25
Issue number: 3
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2018): CiteScore 11.8 SJR 2.352 SNIP 4.212
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85049615601

Research output: Contribution to journalArticleScientificpeer-review

The effect of percutaneous transluminal angioplasty of superficial femoral artery on pulse wave features

We aimed to analyze the effects of percutaneous transluminal angioplasty (PTA) of the superficial femoral artery (SFA) on arterial pulse waves (PWs). Altogether 24 subjects i.e. 48 lower limbs were examined including 26 treated lower limbs having abnormal ankle-to-brachial pressure index (ABI) (ABI<0.9 or ABI>1.3) and 22 non-treated lower limbs. The measurements were conducted in pre-, peri- and post-treatment phases as well as in follow-up visit after 1 month. Both ABI and toe pressures measured by standard equipment were used as reference values. PW-derived parameters include ratios of different peaks of the PW and time differences between them as well as aging index. Both treated and non-treated limbs were compared in pre- and post-treatment as well as follow-up visit conditions. The results were evaluated in terms of statistical tests, Bland-Altman-plots, free-marginal multirater κ-analysis and multiple linear regression analysis. PTA was found to cause small changes to the studied PW-derived parameters of the treated limb which were observed immediately after the treatment, but the changes were more pronounced in the follow-up visit. In addition, we observed that the endovascular instrumentation itself does not cause significant changes to the PW-derived parameters. The results show that PW-analysis could be a useful tool for monitoring the treatment-effect of the PTA. However, because the pre-treatment differences of the treated and non-treated limb were small, further studies with subjects having no arterial diseases are required. The study demonstrates the potential of the PW analysis in monitoring vascular abnormalities.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Sensor Technology and Biomeasurements (STB), Tampere University Hospital
Contributors: Peltokangas, M., Suominen, V., Vakhitov, D., Verho, J., Korhonen, J., Lekkala, J., Vehkaoja, A., Oksala, N.
Number of pages: 9
Pages: 274-282
Publication date: 1 May 2018
Peer-reviewed: Yes

Publication information

Journal: Computers in Biology and Medicine
Volume: 96
ISSN (Print): 0010-4825
Ratings: 
  • Scopus rating (2018): CiteScore 2.79 SJR 0.57 SNIP 1.169
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Health Informatics
Keywords: Atherosclerosis, Electromechanical sensors, Peripheral arterial disease, Photoplethysmography, Pulse wave measurements
Electronic versions: 
URLs: 
Source: Scopus
Source ID: 85045471212

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 3.92 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

Wirelessly powered urban crowd sensing over wearables: Trading energy for data

In this article, we put forward the paradigm of mobile crowd sensing based on ubiquitous wearable devices carried by human users. The key challenge for mass user involvement in prospective urban crowd sensing applications, such as monitoring of large-scale phenomena (e.g., traffic congestion and air pollution levels), is the appropriate sources of motivation. We thus advocate for the use of wireless power transfer provided in exchange for sensed data to incentivize the owners of wearables to participate in collaborative data collection. Based on this construction, we develop a novel concept of wirelessly powered crowd sensing and offer the corresponding network architecture considerations together with a systematic review of wireless charging techniques to support implementation. Further, we contribute a detailed system-level feasibility study that reports on the achievable performance levels for the envisioned setup. Finally, the underlying energy- data trading mechanisms are discussed, and the work concludes with outlining open research opportunities.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Peoples' Friendship University of Russia, Univ of Oulu, University of Hong Kong
Contributors: Galinina, O., Mikhaylov, K., Huang, K., Andreev, S., Koucheryavy, Y.
Number of pages: 10
Pages: 140-149
Publication date: 1 Apr 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 25
Issue number: 2
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2018): CiteScore 11.8 SJR 2.352 SNIP 4.212
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85046828147

Research output: Contribution to journalArticleScientificpeer-review

Generic platform for manufacturing execution system functions in knowledge-driven manufacturing systems

Information technologies grow rapidly nowadays with the advance and extension of computing capabilities. This growth affects several fields, which consume these technologies. Industrial Automation is not an exception. This publication describes a general and flexible architecture for implementing Manufacturing Execution System (MES) function, which can be deployed in multiple industrial cases. These features are achieved by combining the flexibility of knowledge-driven systems with the vendor-independent property of RESTful web services. With deployment of this solution, MES functions may gain more versatility and independency. This research work is a continuation of the development of the OKD-MES (Open Knowledge-Driven Manufacturing Execution System) framework during the execution of the eScop project. The OKD-MES framework consists on a semantic-based solution for controlling and enhancing the flexibility and re-configurability of MES. In such scope, this research presents MES functions architecture that might be implemented in the OKD-MES framework in order to increase the flexibility of event-driven manufacturing systems.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering, Research group: Factory automation systems technology, Politecnico di Milano
Contributors: Mohammed, W. M., Ramis Ferrer, B., Iarovyi, S., Negri, E., Fumagalli, L., Lobov, A., Martinez Lastra, J. L.
Number of pages: 13
Pages: 1-13
Publication date: 4 Mar 2018
Peer-reviewed: Yes

Publication information

Journal: International Journal of Computer Integrated Manufacturing
ISSN (Print): 0951-192X
Ratings: 
  • Scopus rating (2018): CiteScore 3.08 SJR 0.878 SNIP 1.447
Original language: English
ASJC Scopus subject areas: Aerospace Engineering, Mechanical Engineering, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Knowledge-driven manufacturing systems, manufacturing execution system functions, semantics
Source: Scopus
Source ID: 85034843058

Research output: Contribution to journalArticleScientificpeer-review

Noise minimized high resolution digital holographic microscopy applied to surface topography

The topography of surface relief gratings was studied by digital holographic microscopy. The applicability of the method for quantitative measurements of surface microstructure at nanoscale was demonstrated. The method for wavefront reconstruction of surface relief from a digital hologram recorded in off-axis configuration was also applied. The main feature is noise filtration due to the presence of noise in the recorded intensity distribution and the use of all orders of the hologram. Reconstruction results proved a better effectiveness of our approach for topography studying of relief grating patterned on a ChG As2S3 - Se nanomultilayers in comparison with standard Fourier Transform and Atom Force Microscope methods.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Computational Imaging-CI, Institute of Applied Physics Academy of Sciences of Moldava, University of Stuttgart, St. Petersburg State University, Department of Signal Processing
Contributors: Achimova, E., Abaskin, V., Claus, D., Pedrini, G., Shevkunov, I., Katkovnik, V.
Number of pages: 6
Pages: 267-272
Publication date: 1 Mar 2018
Peer-reviewed: Yes

Publication information

Journal: Computer Optics
Volume: 42
Issue number: 2
ISSN (Print): 0134-2452
Ratings: 
  • Scopus rating (2018): CiteScore 2.37 SJR 0.535 SNIP 2.365
Original language: English
ASJC Scopus subject areas: Atomic and Molecular Physics, and Optics, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Diffraction gratings, Digital holography, Digital image processing
Source: Scopus
Source ID: 85046122008

Research output: Contribution to journalArticleScientificpeer-review

Technologies for Efficient Amateur Drone Detection in 5G Millimeter-Wave Cellular Infrastructure

Unmanned aerial vehicles, also called drones, are recently gaining increased research attention across various fields due to their flexibility and application potential. The steady increase in the number of amateur drones demands more stringent regulations on their allowed route, mass, and load. However, these regulations may be violated accidentally or deliberately. In these cases, spying with drones, transfer of dangerous payloads, or losing reliable drone control can represent a new hazard for people, governments, and business sector. The technologies to detect, track, and disarm possible aerial threats are therefore in prompt demand. To this end, ubiquitous cellular networks, and especially 5G infrastructures based on the use of millimeter-wave radio modules, may be efficiently leveraged to offer the much needed drone detection capabilities. In this work, we propose to exploit 5G millimeter-wave deployments to detect violating amateur drones. We argue that the prospective 5G infrastructure may provide all the necessary technology elements to support efficient detection of small-sized drones. We therefore outline a novel technology and system design perspective, including such considerations as the density of base stations, their directional antennas, and the available bandwidth, among others, as well as characterize their impact with our ray-based modeling methods.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Aalto University
Contributors: Solomitckii, D., Gapeyenko, M., Semkin, V., Andreev, S., Koucheryavy, Y.
Number of pages: 8
Pages: 43-50
Publication date: 1 Jan 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 56
Issue number: 1
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2018): CiteScore 11.27 SJR 2.373 SNIP 4.903
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85040720734

Research output: Contribution to journalArticleScientificpeer-review

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

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

General information

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

Publication information

Journal: Structural and Multidisciplinary Optimization
Volume: 57
Issue number: 2
ISSN (Print): 1615-147X
Ratings: 
  • Scopus rating (2018): CiteScore 4.28 SJR 1.835 SNIP 1.887
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Software, Computer Science Applications, Computer Graphics and Computer-Aided Design, Control and Optimization
Keywords: Discrete optimization, Frame structures, Global optimization, Mixed-integer linear programming, Sizing optimization
Source: Scopus
Source ID: 85026724545

Research output: Contribution to journalArticleScientificpeer-review

Effect of paint baking treatment on the properties of press hardened boron steels

This study comprehends the effect of a typical paint baking process on the properties of press hardened boron steels. Bake hardening response of four 22MnB5 steels with different production histories and two other boron steels of 30MnB5 and 34MnB5 type were analyzed. In particular, the effect of steel carbon content and prior austenite grain size on the strength of the bake hardening treated steels was investigated. Press hardened steels showed a relatively strong bake hardening effect, 80–160 MPa, in terms of yield strength. In addition, a clear decrease in ultimate tensile strength, 30–150 MPa, was observed due to baking. The changes in tensile strength showed a dependency on the carbon content of the steel: higher carbon content led to a larger decrease in tensile strength in general. Smaller prior austenite grain size resulted in a higher increase in yield strength despite the micro-alloyed 34MnB5. Transmission electron microscopy analysis carried out for the 34MnB5 revealed niobium rich mixture carbides of (Nb, Ti)C, which have most likely influenced the different bake hardening response. The present results indicate that the bake hardening response of press hardened steels depends on both prior austenite grain size and carbon content, but is also affected by other alloying elements. The observed correlation between prior austenite grain size and bake hardening response can be used to optimize the production of the standard grades of 22MnB5 and 30MnB5. In addition, our study suggests that baking process improves the post-uniform elongation and ductile fracture behavior of 34MnB5, but do not significantly influence the ductile fracture mechanisms of 22MnB5 and 30MnB5 representing lower strength levels.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Materials Science, Research group: Metals Technology, SSAB
Contributors: Järvinen, H., Honkanen, M., Järvenpää, M., Peura, P.
Number of pages: 15
Pages: 90-104
Publication date: 2018
Peer-reviewed: Yes
Early online date: 11 Sep 2017

Publication information

Journal: Journal of Materials Processing Technology
Volume: 252
ISSN (Print): 0924-0136
Ratings: 
  • Scopus rating (2018): CiteScore 5.08 SJR 1.719 SNIP 2.888
Original language: English
ASJC Scopus subject areas: Ceramics and Composites, Modelling and Simulation, Computer Science Applications, Metals and Alloys, Industrial and Manufacturing Engineering
Keywords: Bake hardening, EBSD, Martensite, Paint baking, Press hardening, Prior austenite grain size
Electronic versions: 
URLs: 
Source: Scopus
Source ID: 85029389667

Research output: Contribution to journalArticleScientificpeer-review

Robust Regulation of Infinite-Dimensional Port-Hamiltonian Systems

We will give general sufficient conditions under which a controller achieves robust regulation for a boundary control and observation system. Utilizing these conditions we construct a minimal order robust controller for an arbitrary order impedance passive linear port-Hamiltonian system. The theoretical results are illustrated with a numerical example where we implement a controller for a one-dimensional Euler-Bernoulli beam with boundary controls and boundary observations.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Research group: Computer Science and Applied Logics
Contributors: Humaloja, J., Paunonen, L.
Publication date: 2018
Peer-reviewed: Yes
Early online date: 31 Aug 2017

Publication information

Journal: IEEE Transactions on Automatic Control
Volume: 63
Issue number: 5
ISSN (Print): 0018-9286
Ratings: 
  • Scopus rating (2018): CiteScore 6.72 SJR 3.233 SNIP 2.641
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Aerospace electronics, Closed loop systems, distributed parameter systems, Generators, Impedance, linear systems, port-Hamiltonian systems, robust control, Robustness, Transfer functions
Electronic versions: 
Source: Scopus
Source ID: 85029173308

Research output: Contribution to journalArticleScientificpeer-review

Reduced Order Internal Models in the Frequency Domain

The internal model principle states that all robustly regulating controllers must contain a suitably reduplicated internal model of the signal to be regulated. Using frequency domain methods, we show that the number of the copies may be reduced if the class of perturbations in the problem is restricted. We present a two stage design procedure for a simple controller containing a reduced order internal model achieving robust regulation. The results are illustrated with an example of a five tank laboratory process where a restricted class of perturbations arises naturally.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Research group: Computer Science and Applied Logics
Contributors: Laakkonen, P., Paunonen, L.
Pages: 1806-1812
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Automatic Control
Volume: 63
Issue number: 6
ISSN (Print): 0018-9286
Ratings: 
  • Scopus rating (2018): CiteScore 6.72 SJR 3.233 SNIP 2.641
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Adaptive control, Aerospace electronics, Frequency control, Frequency-domain analysis, Linear systems, Mathematical model, model/controller reduction, output tracking, robust control, Robustness, Uncertainty
Electronic versions: 
Source: Scopus
Source ID: 85030308353

Research output: Contribution to journalArticleScientificpeer-review

A Primal Neural Network for Online Equality-Constrained Quadratic Programming

This paper aims at solving online equality-constrained quadratic programming problem, which is widely encountered in science and engineering, e.g., computer vision and pattern recognition, digital signal processing, and robotics. Recurrent neural networks such as conventional GradientNet and ZhangNet are considered as powerful solvers for such a problem in light of its high computational efficiency and capability of circuit realisation. In this paper, an improved primal recurrent neural network and its electronic implementation are proposed and analysed. Compared to the existing recurrent networks, i.e. GradientNet and ZhangNet, our network can theoretically guarantee superior global exponential convergence. Robustness performance of our such neural model is also analysed under a large model implementation error, with the upper bound of stead-state solution error estimated. Simulation results demonstrate theoretical analysis on the proposed model, which also verify the effectiveness of the proposed model for online equality-constrained quadratic programming.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Vision, Shanghai Institute of Ceramics Chinese Academy of Sciences, Institute of Automation Chinese Academy of Sciences
Contributors: Chen, K., Zhang, Z.
Number of pages: 8
Pages: 381–388
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: Cognitive Computation
Volume: 10
Issue number: 2
ISSN (Print): 1866-9956
Ratings: 
  • Scopus rating (2018): CiteScore 5.05 SJR 1.06 SNIP 1.965
Original language: English
ASJC Scopus subject areas: Computer Vision and Pattern Recognition, Computer Science Applications, Cognitive Neuroscience
Keywords: Global exponential convergence, Online equality-constrained quadratic programming, Recurrent neural networks, Robustness analysis
Source: Scopus
Source ID: 85030320446

Research output: Contribution to journalArticleScientificpeer-review

How to design gamification? A method for engineering gamified software

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

General information

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

Publication information

Journal: Information and Software Technology
Volume: 95
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2018): CiteScore 5.07 SJR 0.615 SNIP 3.085
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Design science research, Game design, Gameful design, Gamification, Persuasive technology, Playfulness, Software engineering
Source: Scopus
Source ID: 85035150495

Research output: Contribution to journalArticleScientificpeer-review

Gamification, quantified-self or social networking? Matching users’ goals with motivational technology

Systems and services we employ in our daily life have increasingly been augmented with motivational designs which fall under the classes of (1) gamification, (2) quantified-self and (3) social networking features that aim to help users reach their goals via motivational enforcement. However, users differ in terms of their orientation and focus toward goals and in terms of the attributes of their goals. Therefore, different classes of motivational design may have a differential fit for users. Being able to distinguish the goal profiles of users, motivational design could be better tailored. Therefore, in this study we investigate how different goal foci (outcome and focus), goals orientation (mastery, proving, and avoiding), and goal attributes (specificity and difficulty) are associated with perceived importance of gamification, social networking and quantified-self features. We employ survey data ((Formula presented.)) from users of HeiaHeia; a popular exercise encouragement app. Results indicate that goal-setting related factors of users and attributes of goals are connected with users’ preference over motivational design classes. In particular, the results reveal that being outcome-focused is associated with positive evaluations of gamification and quantified-self design classes. Users with higher proving-orientation perceived gamification and social networking design classes as more important, users with lower goal avoidance-orientation perceived social networking design as more important, whereas users with higher mastery-orientation perceived quantified-self design more important. Users with difficult goals were less likely to perceive gamification and social networking design important, whereas for users with high goal specificity quantified-self features were important. The findings provide insights for the automatic adaptation of motivational designs to users’ goals. However, more research is naturally needed to further investigate generalizability of the results.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing, Swedish School of Economics and Business Administration, Aalto University
Contributors: Hamari, J., Hassan, L., Dias, A.
Number of pages: 40
Pages: 35–74
Publication date: 2018
Peer-reviewed: Yes
Early online date: 24 Jan 2018

Publication information

Journal: User Modeling and User-Adapted Interaction
Volume: 28
Issue number: 1
ISSN (Print): 0924-1868
Ratings: 
  • Scopus rating (2018): CiteScore 5.45 SJR 0.907 SNIP 3.544
Original language: English
ASJC Scopus subject areas: Education, Human-Computer Interaction, Computer Science Applications
Keywords: Gamification, Goal orientation, Goal-setting, Motivational information system, Quantified-self, Social networking
Source: Scopus
Source ID: 85040920827

Research output: Contribution to journalArticleScientificpeer-review

System-level analysis of IEEE 802.11ah technology for unsaturated MTC traffic

Enabling the Internet of Things, machine-type communications (MTC) is a next big thing in wireless innovation. In this work, we concentrate on the attractive benefits offered by the emerging IEEE 802.11ah technology to support a large number of MTC devices with extended communication ranges. We begin with a comprehensive overview of the novel features introduced by the latest IEEE 802.11ah specifications followed by the development of a powerful mathematical framework capturing the essential properties of a massive MTC deployment with unsaturated traffic patterns. Further, we compare our analytical findings for a characteristic MTC scenario against respective system-level simulations across a number of important performance indicators. Our analytical results provide adequate performance predictions even when simulations are challenged by the excessive computational complexity. In addition, we study the novel IEEE 802.11ah mechanisms offering improved support for massive device populations and conclude on their expected performance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Ericsson Research
Contributors: Ometov, A., Daneshfar, N., Hazmi, A., Andreev, S., Del Carpio, L. F., Amin, P., Torsner, J., Koucheryavy, Y., Valkama, M.
Number of pages: 14
Pages: 269-282
Publication date: 2018
Peer-reviewed: Yes

Publication information

Journal: International Journal of Sensor Networks
Volume: 26
Issue number: 4
ISSN (Print): 1748-1279
Ratings: 
  • Scopus rating (2018): CiteScore 1.26 SJR 0.269 SNIP 0.545
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Keywords: Analytical modelling, Delay, IEEE 802.11ah, MTC/M2M, Power consumption, Simulations, Throughput, Unsaturated traffic

Bibliographical note

INT=elt"Daneshfar, Nader"

Source: Scopus
Source ID: 85044277791

Research output: Contribution to journalArticleScientificpeer-review

Transmit Power Optimization and Feasibility Analysis of Self-backhauling Full-Duplex Radio Access Systems

We analyze an inband full-duplex access node that is serving mobile users while simultaneously connecting to a core network over a wireless backhaul link, utilizing the same frequency band for all communication tasks. Such wireless self-backhauling is an intriguing option for the next generation wireless systems since a wired backhaul connection might not be economically viable if the access nodes are deployed densely. In particular, we derive the optimal transmit power allocation for such a system in closed form under Quality-of-Service (QoS) requirements, which are defined in terms of the minimum data rates for each mobile user. For comparison, the optimal transmit power allocation is solved also for two reference scenarios: a purely half-duplex access node, and a relay-type full-duplex access node. Based on the obtained expressions for the optimal transmit powers, we then show that the systems utilizing a full-duplex capable access node have a fundamental feasibility boundary, meaning that there are circumstances under which the QoS requirements cannot be fulfilled using finite transmit powers. This fundamental feasibility boundary is also derived in closed form. The feasibility boundaries and optimal transmit powers are then numerically evaluated in order to compare the different communication schemes. In general, utilizing the purely full-duplex access node results in the lowest transmit powers for all the communicating parties, although there are some network geometries under which such a system is not capable of reaching the required minimum data rates. In addition, the numerical results indicate that a full-duplex capable access node is best suited for relatively small cells.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Rice University
Contributors: Korpi, D., Riihonen, T., Sabharwal, A., Valkama, M.
Pages: 4219-4236
Publication date: 2018
Peer-reviewed: Yes
Early online date: 7 Apr 2018

Publication information

Journal: IEEE Transactions on Wireless Communications
Volume: 17
Issue number: 6
ISSN (Print): 1536-1276
Ratings: 
  • Scopus rating (2018): CiteScore 7.79 SJR 1.692 SNIP 2.592
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering, Applied Mathematics
Keywords: full-duplex wireless, massive MIMO, Self-backhauling, transmit power optimization
Electronic versions: 
Source: Scopus
Source ID: 85045199222

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 6.9 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

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 11.56 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

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 5.25 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

How developers perceive smells in source code: A replicated study

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

General information

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

Publication information

Journal: Information and Software Technology
Volume: 92
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2017): CiteScore 4.04 SJR 0.581 SNIP 2.913
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Antipatterns, Bad smells, Code smells, Refactoring, Software maintenance
Source: Scopus
Source ID: 85028762206

Research output: Contribution to journalArticleScientificpeer-review

Fast Water Simulation Methods for Games

Easy-To-use physics engines have created a whole new source of emergence and fun for digital games.Water simulation could add another similar emergent interaction element in 3D games. Several barriers that prevent this step for games with large playing areas are analysed. One of the most important problems is howto couple the water and physics simulations. Our implementation of the extremely fast virtual pipe method is compared with more sophisticated solvers. Also, two different implementations of physics coupling are compared.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pervasive Computing
Contributors: Kellomäki, T.
Publication date: 1 Dec 2017
Peer-reviewed: Yes

Publication information

Journal: Computers in Entertainment
Volume: 16
Issue number: 1
Article number: 2
ISSN (Print): 1544-3574
Ratings: 
  • Scopus rating (2017): CiteScore 0.5 SJR 0.133 SNIP 0.786
Original language: English
ASJC Scopus subject areas: Computer Science Applications
Keywords: Fluid simulation, Games, Pipe method, Realtime, Rigid body coupling, Water simulation
Source: Scopus
Source ID: 85040027871

Research output: Contribution to journalArticleScientificpeer-review

DoGlycans-Tools for Preparing Carbohydrate Structures for Atomistic Simulations of Glycoproteins, Glycolipids, and Carbohydrate Polymers for GROMACS

Carbohydrates constitute a structurally and functionally diverse group of biological molecules and macromolecules. In cells they are involved in, e.g., energy storage, signaling, and cell-cell recognition. All of these phenomena take place in atomistic scales, thus atomistic simulation would be the method of choice to explore how carbohydrates function. However, the progress in the field is limited by the lack of appropriate tools for preparing carbohydrate structures and related topology files for the simulation models. Here we present tools that fill this gap. Applications where the tools discussed in this paper are particularly useful include, among others, the preparation of structures for glycolipids, nanocellulose, and glycans linked to glycoproteins. The molecular structures and simulation files generated by the tools are compatible with GROMACS.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Physics, Research group: Biological Physics and Soft Matter, University of Helsinki, Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, MEMPHYS - Centre for Biomembrane Physics, University of Southern Denmark, Laboratory of Physics
Contributors: Danne, R., Poojari, C., Martinez-Seara, H., Rissanen, S., Lolicato, F., Róg, T., Vattulainen, I.
Number of pages: 6
Pages: 2401-2406
Publication date: 23 Oct 2017
Peer-reviewed: Yes

Publication information

Journal: Journal of Chemical Information and Modeling
Volume: 57
Issue number: 10
ISSN (Print): 1549-9596
Ratings: 
  • Scopus rating (2017): CiteScore 3.9 SJR 1.349 SNIP 1.213
Original language: English
ASJC Scopus subject areas: Chemistry(all), Chemical Engineering(all), Computer Science Applications, Library and Information Sciences
Source: Scopus
Source ID: 85031999962

Research output: Contribution to journalArticleScientificpeer-review

An ensemble of visual features for Gaussians of local descriptors and non-binary coding for texture descriptors

This paper presents an improved version of a recent state-of-the-art texture descriptor called Gaussians of Local Descriptors (GOLD), which is based on a multivariate Gaussian that models the local feature distribution that describes the original image. The full rank covariance matrix, which lies on a Riemannian manifold, is projected on the tangent Euclidean space and concatenated to the mean vector for representing a given image. In this paper, we test the following features for describing the original image: scale-invariant feature transform (SIFT), histogram of gradients (HOG), and weber's law descriptor (WLD). To improve the baseline version of GOLD, we describe the covariance matrix using a set of visual features that are fed into a set of Support Vector Machines (SVMs). The SVMs are combined by sum rule. The scores obtained by an SVM trained using the original GOLD approach and the SVMs trained with visual features are then combined by sum rule. Experiments show that our proposed variant outperforms the original GOLD approach. The superior performance of the proposed system is validated across a large set of datasets. Particularly interesting is the performance obtained in two widely used person re-identification datasets, CAVIAR4REID and IAS, where the proposed GOLD variant is coupled with a state-of-the-art ensemble to obtain an improvement of performance on these two datasets. Moreover, we performed further tests that combine GOLD with non-binary features (local ternary/quinary patterns) and deep transfer learning. The fusion among SVMs trained with deep features and the SVMs trained using the ternary/quinary coding ensemble is demonstrated to obtain a very high performance across datasets. The MATLAB code for the ensemble of classifiers and for the extraction of the features will be publicly available1 to other researchers for future comparisons.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Computational Biophysics and Imaging Group, BioMediTech, Universita degli Studi di Padova, Italy, BioMediTech Institute and Faculty of Biomedical Sciences and Engineering, Missouri State University
Contributors: Nanni, L., Paci, M., Brahnam, S., Ghidoni, S.
Number of pages: 13
Pages: 27-39
Publication date: 1 Oct 2017
Peer-reviewed: Yes

Publication information

Journal: Expert Systems with Applications
Volume: 82
ISSN (Print): 0957-4174
Ratings: 
  • Scopus rating (2017): CiteScore 5.22 SJR 1.271 SNIP 2.538
Original language: English
ASJC Scopus subject areas: Engineering(all), Computer Science Applications, Artificial Intelligence
Keywords: Ensemble of descriptors, Image classification, Image processing, Person re-identification, Texture
Source: Scopus
Source ID: 85017166137

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 5.25 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

Adaptive and nonlinear control of discharge pressure for variable displacement axial piston pumps

This paper proposes, for the first time without using any linearization or order reduction, an adaptive and model-based discharge pressure control design for the variable displacement axial piston pumps (VDAPPs), whose dynamical behaviors are highly nonlinear and can be described by a fourth-order differential equation. The rigorous stability proof, with an asymptotic convergence, is given for the entire system. In the proposed novel controller design method, the specifically designed stabilizing terms constitute an essential core to cancel out all the stability-preventing terms. The experimental results reveal that rapid parameter adaptation significantly improves the feedback signal tracking precision compared to a known-parameter controller design. In the comparative experiments, the adaptive controller design demonstrates the state-of-the-art discharge pressure control performance, enabling a possibility for energy consumption reductions in hydraulic systems driven with VDAPP.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering, Research group: Mobile manipulation
Contributors: Koivumäki, J., Mattila, J.
Publication date: 1 Oct 2017
Peer-reviewed: Yes

Publication information

Journal: Journal of Dynamic Systems, Measurement and Control: Transactions of the ASME
Volume: 139
Issue number: 10
Article number: 101008
ISSN (Print): 0022-0434
Ratings: 
  • Scopus rating (2017): CiteScore 1.74 SJR 0.618 SNIP 1.024
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Information Systems, Instrumentation, Mechanical Engineering, Computer Science Applications
Source: Scopus
Source ID: 85021623538

Research output: Contribution to journalArticleScientificpeer-review

On the Performance of Visible Light Communication Systems with Non-Orthogonal Multiple Access

Visible light communication (VLC) has been proposed as a promising and efficient solution to indoor ubiquitous broadband connectivity. In this paper, non-orthogonal multiple access, which has been recently introduced as an effective scheme for fifth generation (5G) wireless networks, is considered in the context of VLC systems under different channel uncertainty models. To this end, we first derive a novel closed-form expression for the bit-error-rate (BER) under perfect channel state information (CSI). Capitalizing on this, we then quantify the effect of noisy and outdated CSI by deriving a simple and accurate approximation for the former and a tight upper bound for the latter. The offered results are corroborated by respective results from extensive Monte Carlo simulations and assist in developing useful insights on the effect of imperfect CSI knowledge on the overall system performance. Furthermore, it was shown that while noisy CSI leads to slight degradation in the BER performance, outdated CSI can cause considerable performance degradation, if the order of the users' channel gains change due to the involved mobility.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Khalifa University, Department of Electrical and Computer Engineering, University of Surrey, Aristotle University of Thessaloniki
Contributors: Marshoud, H., Sofotasios, P. C., Muhaidat, S., Karagiannidis, G. K., Sharif, B. S.
Number of pages: 15
Pages: 6350-6364
Publication date: 1 Oct 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Wireless Communications
Volume: 16
Issue number: 10
ISSN (Print): 1536-1276
Ratings: 
  • Scopus rating (2017): CiteScore 6.43 SJR 1.246 SNIP 2.405
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering, Applied Mathematics
Keywords: bit-error-rate, dimming control, imperfect channel state information, non-orthogonal multiple access, Visible light communications
Source: Scopus
Source ID: 85023196523

Research output: Contribution to journalArticleScientificpeer-review

The Effect of Ultrasonic Dispersion on the Surface Chemistry of Carbon Nanotubes in the Jeffamine D-230 Polyetheramine Medium

This paper studies changes in the surface chemistry of carbon nanotubes (CNTs) where they are under ultrasonication process in Jeffamine D-230 polyetheramine medium. Jeffamine is used as a curing agent in the nanocomposite manufacturing process. In the nanocomposite technology, ultrasonication process is employed as a method for dispersion of CNTs in a suspension. This research tries to investigate the effect of ultrasonic dispersion with different time and energy on the surface chemistry of CNTs by Fourier transform infrared spectroscopy. The results show ultrasonication of CNTs in the Jeffamine medium leads to significant oxidation and hydration along creating new chemical bonds on the CNTs surface.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Materials Science, Research group: Plastics and Elastomer Technology
Contributors: Shahshahan, M., Keinänen, P., Vuorinen, J.
Number of pages: 4
Pages: 741-744
Publication date: 1 Sep 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Nanotechnology
Volume: 16
Issue number: 5
ISSN (Print): 1536-125X
Ratings: 
  • Scopus rating (2017): CiteScore 2.86 SJR 0.572 SNIP 1.146
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Keywords: Carbon nanotubes, characterization of functional groups, dispersion of carbon nanotubes, Fourier transform infrared (FTIR) spectroscopy, functionalization, optical spectroscopy, sonicated carbon nanotubes, sonochemistry, surface chemistry of carbon nanotubes, ultrasonication

Bibliographical note

EXT="Shahshahan, Mohsen"

Source: Scopus
Source ID: 85029628879

Research output: Contribution to journalArticleScientificpeer-review

Robust Output Regulation for Continuous-Time Periodic Systems

We consider controller design for robust output tracking and disturbance rejection for continuous-time periodic linear systems with periodic reference and disturbance signals. As our main results, we present four different controllers: a feedforward control law and a discrete-time dynamic error feedback controller for output tracking and disturbance rejection, a robust discrete-time feedback controller, and finally a discrete-time feedback controller that achieves approximate robust output tracking and disturbance rejection. The presented constructions are also new for time-invariant finite and infinite-dimensional systems. The results are illustrated with two examples: a periodically time-dependent system of harmonic oscillators and a nonautonomous two-dimensional heat equation with boundary disturbance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Research group: Computer Science and Applied Logics
Contributors: Paunonen, L.
Number of pages: 13
Pages: 4363-4375
Publication date: 1 Sep 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Automatic Control
Volume: 62
Issue number: 9
ISSN (Print): 0018-9286
Ratings: 
  • Scopus rating (2017): CiteScore 5.9 SJR 3.433 SNIP 3.068
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Controller design, feedback, periodic system, robust output regulation
Electronic versions: 
Source: Scopus
Source ID: 85029869750

Research output: Contribution to journalArticleScientificpeer-review

Energy Efficiency Maximization of Full-Duplex Two-Way Relay with Non-Ideal Power Amplifiers and Non-Negligible Circuit Power

In this paper, we maximize the energy efficiency (EE) of full-duplex (FD) two-way relay (TWR) systems under non-ideal power amplifiers (PAs) and non-negligible transmission-dependent circuit power. We start with the case where only the relay operates full duplex and two timeslots are required for TWR. Then, we extend to the advanced case, where the relay and the two nodes all operate full duplex, and accomplish TWR in a single timeslot. In both cases, we establish the intrinsic connections between the optimal transmit powers and durations, based on which the original non-convex EE maximization can be convexified and optimally solved. Simulations show the superiority of FD-TWR in terms of EE, especially when traffic demand is high. The simulations also reveal that the maximum EE of FD-TWR is more sensitive to the PA efficiency, than it is to self-cancellation. The full FD design of FD-TWR is susceptible to traffic imbalance, while the design with only the relay operating in the FD mode exhibits strong tolerance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Beijing University of Posts and Telecommunications, CSIRO Energy Centre, Aalto University
Contributors: Cui, Q., Zhang, Y., Ni, W., Valkama, M., Jantti, R.
Number of pages: 15
Pages: 6264-6278
Publication date: 1 Sep 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Wireless Communications
Volume: 16
Issue number: 9
ISSN (Print): 1536-1276
Ratings: 
  • Scopus rating (2017): CiteScore 6.43 SJR 1.246 SNIP 2.405
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Keywords: Energy efficiency, full-duplex, non-ideal power amplifier, non-negligible circuit power, two-way relay
Source: Scopus
Source ID: 85023192668

Research output: Contribution to journalArticleScientificpeer-review

Indirect NOx emission monitoring in natural gas fired boilers

New emission regulations will increase the need for inexpensive NOx emission monitoring solutions also in smaller power plants. The objective in this study is to find easily maintainable and transparent but still valid models to predict NOx emissions in natural gas fired hot water boilers utilizing existing process instrumentation. With a focus on long-term applicability in practical installations, the performance of linear regression is compared in two municipal 43 MW boilers with three widely used nonlinear methods: multilayer perceptron, support vector regression, and fuzzy inference system. The linear models were the most applicable providing the best estimation results (relative error of 1 applications in practise. However, each boiler model should be identified individually.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Automation and Hydraulic Engineering, Research area: Measurement Technology and Process Control, Helen Ltd.
Contributors: Korpela, T., Kumpulainen, P., Majanne, Y., Häyrinen, A., Lautala, P.
Number of pages: 15
Pages: 11-25
Publication date: 1 Aug 2017
Peer-reviewed: Yes

Publication information

Journal: Control Engineering Practice
Volume: 65
ISSN (Print): 0967-0661
Ratings: 
  • Scopus rating (2017): CiteScore 3.42 SJR 1.069 SNIP 1.905
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Keywords: Combustion, Estimation, Modelling, Monitoring, Natural gas, NO, Soft sensor
Electronic versions: 
URLs: 
Source: Scopus
Source ID: 85019718306

Research output: Contribution to journalArticleScientificpeer-review

sgnesR: An R package for simulating gene expression data from an underlying real gene network structure considering delay parameters

Background: sgnesR (Stochastic Gene Network Expression Simulator in R) is an R package that provides an interface to simulate gene expression data from a given gene network using the stochastic simulation algorithm (SSA). The package allows various options for delay parameters and can easily included in reactions for promoter delay, RNA delay and Protein delay. A user can tune these parameters to model various types of reactions within a cell. As examples, we present two network models to generate expression profiles. We also demonstrated the inference of networks and the evaluation of association measure of edge and non-edge components from the generated expression profiles. Results: The purpose of sgnesR is to enable an easy to use and a quick implementation for generating realistic gene expression data from biologically relevant networks that can be user selected. Conclusions: sgnesR is freely available for academic use. The R package has been tested for R 3.2.0 under Linux, Windows and Mac OS X.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: BioMediTech, Faculty of Biomedical Sciences and Engineering, Signal Processing, Research group: Laboratory of Biosystem Dynamics-LBD, Research group: Computational Systems Biology, Research group: Computational Medicine and Statistical Learning Laboratory (CMSL), Research group: Predictive Society and Data Analytics (PSDA), Harvard T.H. Chan School of Public Health, Harvard School of Public Health, Mathematics and Operations Research
Contributors: Tripathi, S., Lloyd-Price, J., Ribeiro, A., Yli-Harja, O., Dehmer, M., Emmert-Streib, F.
Publication date: 4 Jul 2017
Peer-reviewed: Yes

Publication information

Journal: BMC Bioinformatics
Volume: 18
Issue number: 1
Article number: 325
ISSN (Print): 1471-2105
Ratings: 
  • Scopus rating (2017): CiteScore 2.49 SJR 1.479 SNIP 0.907
Original language: English
ASJC Scopus subject areas: Structural Biology, Biochemistry, Molecular Biology, Computer Science Applications, Applied Mathematics
Keywords: Gene expression data, Gene network, Simulation
Electronic versions: 
Source: Scopus
Source ID: 85021637056

Research output: Contribution to journalArticleScientificpeer-review

A Proxy-Based Solution for Asynchronous Telemedical Systems

Asynchronous telemedicine systems face many challenges related to information security as the patient's sensitive information and data on medicine dosage is transmitted over a network when monitoring patients and controlling asynchronous telemedical IoT devices. This information may be modified or spied on by a malicious adversary. To make asynchronous telemedicine systems more secure, the authors present a proxy-based solution against data modification and spying attacks in web-based telemedical applications. By obfuscating the executable code of a web application and by continuously dynamically changing obfuscation, the authors' solution makes it more difficult for a piece of malware to attack its target. They use a constructive research approach. They characterize the threat and present an outline of a proposed solution. The benefits and limitations of the proposed solution are discussed. Cyber-Attacks targeted at the information related to patient's care are a serious threat in today's telemedicine. If disregarded, these attacks have negative implications on patient safety and quality of care.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: Software Engineering and Intelligent Systems, Pervasive Computing
Contributors: Rauti, S., Lahtiranta, J., Parisod, H., Hyrynsalmi, S., Salanterä, S., Aromaa, M. E., Smed, J., Leppänen, V.
Number of pages: 14
Pages: 70-83
Publication date: 1 Jul 2017
Peer-reviewed: Yes

Publication information

Journal: International Journal of E-health and Medical Communication
Volume: 8
Issue number: 3
Article number: 5
ISSN (Print): 1947-315X
Ratings: 
  • Scopus rating (2017): CiteScore 0.62 SJR 0.129 SNIP 0.403
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Health Informatics
Keywords: Asynchronous Telemedicine, Man-in-The-Middle Attacks, Obfuscation, Telemedical IoT Devices, Web Application Security
Source: Scopus
Source ID: 85020175149

Research output: Contribution to journalArticleScientificpeer-review

The Fisher-Snedecor F Distribution: A Simple and Accurate Composite Fading Model

We consider the use of the Fisher-Snedecor F distribution, which is defined as the ratio of two chi-squared variates, to model composite fading channels. In this context, the root-mean-square power of a Nakagami- m signal is assumed to be subject to variations induced by an inverse Nakagami- m random variable. Comparisons with physical channel data demonstrate that the proposed composite fading model provides as good, and in most cases better, fit to the data compared to the generalized- K composite fading model. Motivated by this result, simple novel expressions are derived for the key statistical metrics and performance measures of interest.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Queen's University, Belfast, Northern Ireland, Aristotle University of Thessaloniki
Contributors: Yoo, S. K., Cotton, S. L., Sofotasios, P. C., Matthaiou, M., Valkama, M., Karagiannidis, G. K.
Number of pages: 4
Pages: 1661-1664
Publication date: 1 Jul 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Letters
Volume: 21
Issue number: 7
ISSN (Print): 1089-7798
Ratings: 
  • Scopus rating (2017): CiteScore 3.01 SJR 0.589 SNIP 1.38
Original language: English
ASJC Scopus subject areas: Modelling and Simulation, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Composite fading, inverse Nakagami-m distribution, Nakagami-m fading, shadowing.
Source: Scopus
Source ID: 85029841155

Research output: Contribution to journalArticleScientificpeer-review

CNN-based edge filtering for object proposals

Recent advances in image-based object recognition have exploited object proposals to speed up the detection process by reducing the search space. In this paper, we present a novel idea that utilizes true objectness and semantic image filtering (retrieved within the convolutional layers of a Convolutional Neural Network) to propose effective region proposals. Information learned in fully convolutional layers is used to reduce the number of proposals and enhance their localization by producing highly accurate bounding boxes. The greatest benefit of our method is that it can be integrated into any existing approach exploiting edge-based objectness to achieve consistently high recall across various intersection over union thresholds. Experiments on PASCAL VOC 2007 and ImageNet datasets demonstrate that our approach improves two existing state-of-the-art models with significantly high margins and pushes the boundaries of object proposal generation.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: Multimedia Research Group - MRG, Aarhus Universitet
Contributors: Waris, M. A., Iosifidis, A., Gabbouj, M.
Pages: 631-640
Publication date: 2 Jun 2017
Peer-reviewed: Yes

Publication information

Journal: Neurocomputing
Volume: 266
ISSN (Print): 0925-2312
Ratings: 
  • Scopus rating (2017): CiteScore 3.74 SJR 1.073 SNIP 1.56
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Cognitive Neuroscience, Artificial Intelligence
Keywords: Deep learning, Neural networks, Object detection, Object proposals, Region of interest
Source: Scopus
Source ID: 85020766935

Research output: Contribution to journalArticleScientificpeer-review

A Mixed Finite Element Method to Solve the EEG Forward Problem

Finite element methods have been shown to achieve high accuracies in numerically solving the EEG forward problem and they enable the realistic modeling of complex geometries and important conductive features such as anisotropic conductivities. To date, most of the presented approaches rely on the same underlying formulation, the continuous Galerkin (CG)-FEM. In this article, a novel approach to solve the EEG forward problem based on a mixed finite element method (Mixed-FEM) is introduced. To obtain the Mixed-FEM formulation, the electric current is introduced as an additional unknown besides the electric potential. As a consequence of this derivation, the Mixed-FEM is, by construction, current preserving, in contrast to the CG-FEM. Consequently, a higher simulation accuracy can be achieved in certain scenarios, e.g., when the diameter of thin insulating structures, such as the skull, is in the range of the mesh resolution. A theoretical derivation of the Mixed-FEM approach for EEG forward simulations is presented, and the algorithms implemented for solving the resulting equation systems are described. Subsequently, first evaluations in both sphere and realistic head models are presented, and the results are compared to previously introduced CG-FEM approaches. Additional visualizations are shown to illustrate the current preserving property of the Mixed-FEM. Based on these results, it is concluded that the newly presented Mixed-FEM can at least complement and in some scenarios even outperform the established CG-FEM approaches, which motivates a further evaluation of the Mixed-FEM for applications in bioelectromagnetism.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Research group: Inverse Problems, University of Utah, Cluster of Excellence EXC, University of Münster
Contributors: Vorwerk, J., Engwer, C., Pursiainen, S., Wolters, C. H.
Number of pages: 12
Pages: 930-941
Publication date: 1 Apr 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Medical Imaging
Volume: 36
Issue number: 4
Article number: 7731161
ISSN (Print): 0278-0062
Ratings: 
  • Scopus rating (2017): CiteScore 6.6 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: EEG, forward problem, mixed finite element method, realistic head modeling, source analysis
Source: Scopus
Source ID: 85017598893

Research output: Contribution to journalArticleScientificpeer-review

Neighborhood Matching for Image Retrieval

In the last few years, large-scale image retrieval has attracted a lot of attention from the multimedia community. Usual approaches addressing this task first generate an initial ranking of the reference images using fast approximations that do not take into consideration the spatial arrangement of local features in the image (e.g., the bag-of-words paradigm). The top positions of the rankings are then re-estimated with verification methods that deal with more complex information, such as the geometric layout of the image. This verification step allows pruning of many false positives at the expense of an increase in the computational complexity, which may prevent its application to large-scale retrieval problems. This paper describes a geometric method known as neighborhood matching (NM), which revisits the keypoint matching process by considering a neighborhood around each keypoint and improves the efficiency of a geometric verification step in the image search system. Multiple strategies are proposed and compared to incorporate NM into a large-scale image retrieval framework. A detailed analysis and comparison of these strategies and baseline methods have been investigated. The experiments show that the proposed method not only improves the computational efficiency, but also increases the retrieval performance and outperforms state-of-the-art methods in standard datasets, such as the Oxford 5 k and 105 k datasets, for which the spatial verification step has a significant impact on the system performance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Universidad Carlos III de Madrid, Purdue University
Contributors: González-Díaz, I., Birinci, M., Díaz-De-María, F., Delp, E. J.
Number of pages: 15
Pages: 544-558
Publication date: 1 Mar 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Multimedia
Volume: 19
Issue number: 3
ISSN (Print): 1520-9210
Ratings: 
  • Scopus rating (2017): CiteScore 5.24 SJR 0.954 SNIP 2.302
Original language: English
ASJC Scopus subject areas: Signal Processing, Media Technology, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Geometric verification, image retrieval, neighborhood matching (NM), robust estimation
Source: Scopus
Source ID: 85013466531

Research output: Contribution to journalArticleScientificpeer-review

Interference and SINR in Millimeter Wave and Terahertz Communication Systems With Blocking and Directional Antennas

The fifth generation wireless systems are expected to rely on a large number of small cells to massively offload traffic from the cellular and even from the wireless local area networks. To enable this functionality, mm-wave (EHF) and Terahertz (THF) bands are being actively explored. These bands are characterized by unique propagation properties compared with microwave systems. As a result, the interference structure in these systems could be principally different to what we observed so far at lower frequencies. In this paper, using the tools of stochastic geometry, we study the systems operating in the EHF/THF bands by explicitly capturing three phenomena inherent for these frequencies: 1) high directivity of the transmit and receive antennas; 2) molecular absorption; and 3) blocking of high-frequency radiation. We also define and compare two different antenna radiation pattern models. The metrics of interest are the mean interference and the signal-to-interference-plus-noise (SINR) ratio at the receiver. Our results reveal that: 1) for the same total emitted energy by a Poisson field of interferers, both the interference and SINR significantly increase when simultaneously both transmit and receive antennas are directive and 2) blocking has a profound impact on the interference and SINR creating much more favorable conditions for communications compared with no blocking case.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, State University of New York
Contributors: Petrov, V., Komarov, M., Moltchanov, D., Jornet, J. M., Koucheryavy, Y.
Number of pages: 18
Pages: 1791-1808
Publication date: 1 Mar 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Wireless Communications
Volume: 16
Issue number: 3
ISSN (Print): 1536-1276
Ratings: 
  • Scopus rating (2017): CiteScore 6.43 SJR 1.246 SNIP 2.405
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Applied Mathematics, Electrical and Electronic Engineering
Keywords: 5G systems, blocking, directional antennas, Interference, millimeter waves, terahertz band
Source: Scopus
Source ID: 85015301037

Research output: Contribution to journalArticleScientificpeer-review

Effects of Heterogeneous Mobility on D2D-and Drone-Assisted Mission-Critical MTC in 5G

mcMTC is starting to play a central role in the industrial Internet of Things ecosystem and have the potential to create high-revenue businesses, including intelligent transportation systems, energy/ smart grid control, public safety services, and high-end wearable applications. Consequently, in the 5G of wireless networks, mcMTC have imposed a wide range of requirements on the enabling technology, such as low power, high reliability, and low latency connectivity. Recognizing these challenges, the recent and ongoing releases of LTE systems incorporate support for lowcost and enhanced coverage, reduced latency, and high reliability for devices at varying levels of mobility. In this article, we examine the effects of heterogeneous user and device mobility-produced by a mixture of various mobility patterns-on the performance of mcMTC across three representative scenarios within a multi-connectivity 5G network. We establish that the availability of alternative connectivity options, such as D2D links and drone-Assisted access, helps meet the requirements of mcMTC applications in a wide range of scenarios, including industrial automation, vehicular connectivity, and urban communications. In particular, we confirm improvements of up to 40 percent in link availability and reliability with the use of proximate connections on top of the cellular-only baseline.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Department of Chemistry and Bioengineering, Ericsson Research and Wireless KTH, Ericsson Research, King's College London, Antonio Iera Are with University Mediterranea of Reggio Calabria
Contributors: Orsino, A., Ometov, A., Fodor, G., Moltchanov, D., Militano, L., Andreev, S., Yilmaz, O. N. C., Tirronen, T., Torsner, J., Araniti, G., Iera, A., Dohler, M., Koucheryavy, Y.
Number of pages: 9
Pages: 79-87
Publication date: 1 Feb 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 55
Issue number: 2
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2017): CiteScore 11.06 SJR 2.297 SNIP 5.717
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85012979681

Research output: Contribution to journalArticleScientificpeer-review

Benchmarking DFT methods with small basis sets for the calculation of halogen-bond strengths

In recent years, halogen bonding has become an important design tool in crystal engineering, supramolecular chemistry and biosciences. The fundamentals of halogen bonding have been studied extensively with high-accuracy computational methods. Due to its non-covalency, the use of triple-zeta (or larger) basis sets is often recommended when studying halogen bonding. However, in the large systems often encountered in supramolecular chemistry and biosciences, large basis sets can make the calculations far too slow. Therefore, small basis sets, which would combine high computational speed and high accuracy, are in great demand. This study focuses on comparing how well density functional theory (DFT) methods employing small, double-zeta basis sets can estimate halogen-bond strengths. Several methods with triple-zeta basis sets are included for comparison. Altogether, 46 DFT methods were tested using two data sets of 18 and 33 halogen-bonded complexes for which the complexation energies have been previously calculated with the high-accuracy CCSD(T)/CBS method. The DGDZVP basis set performed far better than other double-zeta basis sets, and it even outperformed the triple-zeta basis sets. Due to its small size, it is well-suited to studying halogen bonding in large systems.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Chemistry and Bioengineering, Research group: Supramolecular photochemistry
Contributors: Siiskonen, A., Priimägi, A.
Publication date: 1 Feb 2017
Peer-reviewed: Yes

Publication information

Journal: Journal of Molecular Modeling
Volume: 23
Issue number: 2
Article number: 50
ISSN (Print): 1610-2940
Ratings: 
  • Scopus rating (2017): CiteScore 1.17 SJR 0.36 SNIP 0.534
Original language: English
ASJC Scopus subject areas: Catalysis, Computer Science Applications, Physical and Theoretical Chemistry, Organic Chemistry, Computational Theory and Mathematics, Inorganic Chemistry
Keywords: Basis set, Benchmarking, Density functional theory, Halogen bonding
Source: Scopus
Source ID: 85011684872

Research output: Contribution to journalArticleScientificpeer-review

GSAR: Bioconductor package for Gene Set analysis in R

Background: Gene set analysis (in a form of functionally related genes or pathways) has become the method of choice for analyzing omics data in general and gene expression data in particular. There are many statistical methods that either summarize gene-level statistics for a gene set or apply a multivariate statistic that accounts for intergene correlations. Most available methods detect complex departures from the null hypothesis but lack the ability to identify the specific alternative hypothesis that rejects the null. Results: GSAR (Gene Set Analysis in R) is an open-source R/Bioconductor software package for gene set analysis (GSA). It implements self-contained multivariate non-parametric statistical methods testing a complex null hypothesis against specific alternatives, such as differences in mean (shift), variance (scale), or net correlation structure. The package also provides a graphical visualization tool, based on the union of two minimum spanning trees, for correlation networks to examine the change in the correlation structures of a gene set between two conditions and highlight influential genes (hubs). Conclusions: Package GSAR provides a set of multivariate non-parametric statistical methods that test a complex null hypothesis against specific alternatives. The methods in package GSAR are applicable to any type of omics data that can be represented in a matrix format. The package, with detailed instructions and examples, is freely available under the GPL (> = 2) license from the Bioconductor web site.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Faculty of Biomedical Sciences and Engineering, Research group: Predictive Society and Data Analytics (PSDA), University of Arkansas for Medical Sciences, Computational Medicine and Statistical Learning Laboratory
Contributors: Rahmatallah, Y., Zybailov, B., Emmert-Streib, F., Glazko, G.
Publication date: 24 Jan 2017
Peer-reviewed: Yes

Publication information

Journal: BMC Bioinformatics
Volume: 18
Issue number: 1
Article number: 61
ISSN (Print): 1471-2105
Ratings: 
  • Scopus rating (2017): CiteScore 2.49 SJR 1.479 SNIP 0.907
Original language: English
ASJC Scopus subject areas: Structural Biology, Biochemistry, Molecular Biology, Computer Science Applications, Applied Mathematics
Keywords: Gene set analysis, Kolmogorov-Smirnov, Minimum spanning tree, Non-parametric, Pathways, Wald Wolfowitz
Source: Scopus
Source ID: 85010460642

Research output: Contribution to journalArticleScientificpeer-review

Architectures and codecs for real-time light field streaming

Light field 3D displays represent a major step forward in visual realism, providing glasses-free spatial vision of real or virtual scenes. Applications that capture and process live imagery have to process data captured by potentially tens to hundreds of cameras and control tens to hundreds of projection engines making up the human perceivable 3D light field using a distributed processing system. The associated massive data processing is difficult to scale beyond a specific number and resolution of images, limited by the capabilities of the individual computing nodes. The authors therefore analyze the bottlenecks and data flow of the light field conversion process and identify possibilities to introduce better scalability. Based on this analysis they propose two different architectures for distributed light field processing. To avoid using uncompressed video data all along the processing chain, the authors also analyze how the operation of the proposed architectures can be supported by existing image/video codecs.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Signal Processing, Research group: 3D MEDIA, Holografika, Nokia
Contributors: Kovács, P. T., Zare, A., Balogh, T., Bregovic, R., Gotchev, A.
Publication date: 1 Jan 2017
Peer-reviewed: Yes

Publication information

Journal: Journal of Imaging Science and Technology
Volume: 61
Issue number: 1
Article number: 010403
ISSN (Print): 1062-3701
Ratings: 
  • Scopus rating (2017): CiteScore 0.59 SJR 0.237 SNIP 0.718
Original language: English
ASJC Scopus subject areas: Electronic, Optical and Magnetic Materials, Chemistry(all), Atomic and Molecular Physics, and Optics, Computer Science Applications
Source: Scopus
Source ID: 85016298177

Research output: Contribution to journalArticleScientificpeer-review

Using enterprise architecture artefacts in an organisation

As a tool for management and planning, Enterprise Architecture (EA) can potentially align organisations’ business processes, information, information systems and technology towards a common goal, and supply the information required within this journey. However, an explicit view on why, how, when and by whom EA artefacts are used in order to realise its full potential is not defined. Utilising the features of information systems use studies and data from a case study with 14 EA stakeholder interviews, we identify and describe 15 EA artefact use situations that are then reflected in the related literature. Their analysis enriches understanding of what are EA artefacts, how and why they are used and when are they used, and results in a theoretical framework for understanding their use in general.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Information Management and Logistics, Research group: Novi, Managing digital industrial transformation (mDIT)
Contributors: Niemi, E., Pekkola, S.
Pages: 313-338
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: Enterprise Information Systems
Volume: 11
Issue number: 3
ISSN (Print): 1751-7575
Ratings: 
  • Scopus rating (2017): CiteScore 2.87 SJR 0.717 SNIP 1.783
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Information Systems and Management
Keywords: artefact, case study, enterprise architecture, use situation, utilisation

Bibliographical note

EXT="Niemi, Eetu"

Source: Scopus
Source ID: 84929593903

Research output: Contribution to journalArticleScientificpeer-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 2.62 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

Nanodevice Arrays for Peripheral Nerve Fascicle Activation Using Ultrasound Energy-harvesting

We propose the use of wireless, energy-harvesting, implanted nanodevice arrays with electrodes for selective stimulation of peripheral nerves in the human body. We calculate the input ultrasound energy and harvested power for single fixed-size nanowire-based nanodevices at different tissue depths and compare these with the current and voltage levels required for peripheral neural stimulation. We model the dimensioning of arrays of nanodevices, embedded in biocompatible tissue patches, to meet these neural stimulation requirements. Selectivity of activation of particular nerve bundles requires that the output voltage and current of the array can be varied to increase or decrease penetration into the neural tissue. This variation can be achieved by changing the energised area of the array and/or by decreasing the incident ultrasound power. However, the array must be implanted horizontally relative to the incident ultrasound as any tilting of the nanodevices will reduce the harvested energy. The proposed approach provides a long-term implant solution for nerve stimulation that allows the patient greater freedom of movement than with embedded tethered electrodes.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, Research group: Emerging Technologies for Nano-Bio-Info-Cogno
Contributors: Donohoe, M., Jennings, B., Jornet, J. M., Balasubramaniam, S.
Pages: 919-930
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Nanotechnology
Volume: 16
Issue number: 6
ISSN (Print): 1536-125X
Ratings: 
  • Scopus rating (2017): CiteScore 2.86 SJR 0.572 SNIP 1.146
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Keywords: Crystals, Electrodes, Energy harvesting, Energy Harvesting, Nanoscale devices, Nanowires, Nerve stimulation, Resonant frequency, Substrates, Ultrasonic imaging, Ultrasound
Electronic versions: 
Source: Scopus
Source ID: 85023197296

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&#x0025; for every projection angle. The relative error of the SNR was less than 1.5&#x0025;, and the NNPS of the simulated images had errors less than 2.5&#x0025;. The 2-AFC human observer experiment yielded no statistically significant difference (p&#x0003D;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&#x0025; 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 6.6 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

Time-Dependent Energy and Resource Management in Mobility-Aware D2D-Empowered 5G Systems

The 5G mobile networks are expected to offer higher degrees of radio access heterogeneity across a wide range of technologies (LTE, WiFi, mmWave, etc.), which operate in both licensed and unlicensed spectrum providing dissimilar data rates and coverage. In light of the stringent requirements in terms of resource and energy efficiency, the performance optimization of such heterogeneous 5G systems becomes an involved task that demands abundant information on the states of users to solve a complex, large-scale optimization problem. However, the unpredictable mobility of communicating entities, including dual mobility of D2D partners, may lead to a rapid deviation from the initial, optimized system state and thus requires frequent re-optimizations of the entire network. In this article, we aim to deliver a comprehensive tutorial on the implications of system-wide energy and resource management with the emphasis on its time-dependent behavior. Proposing a novel network-centric 5G optimization framework, we employ insights from the random walk and Markov chain theories, and also confirm our findings with an extensive system-level simulation campaign. These results reveal an exponential performance degradation rate that primarily depends on the average user speeds. Together with reporting the divergence exponents for different 5G system configurations, we also provide practical insights into how to exploit them in order to non-incrementally improve the throughput and energy performance of the network.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Electronics and Communications Engineering, University of Russia, University Mediterranea of Reggio, RUDN University
Contributors: Orsino, A., Samuylov, A., Moltchanov, D., Andreev, S., Militano, L., Araniti, G., Koucheryavy, Y.
Number of pages: 9
Pages: 14-22
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 24
Issue number: 4
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2017): CiteScore 9.3 SJR 1.878 SNIP 3.627
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 85028851100

Research output: Contribution to journalArticleScientificpeer-review

Advanced boundary electrode modeling for tES and parallel tES/EEG

This paper explores advanced electrode modeling in the context of separate and parallel transcranial electrical stimulation (tES) and electroencephalography (EEG) measurements.We focus on boundary condition based approaches that do not necessitate adding auxiliary elements, e.g. sponges, to the computational domain. In particular, we investigate the complete electrode model (CEM) which incorporates a detailed description of the skin-electrode interface including its contact surface, impedance and normal current distribution. The CEM can be applied for both tES and EEG electrodes which is advantageous when a parallel system is used. In comparison to the CEM, we test two important reduced approaches: the gap model (GAP) and the point electrode model (PEM). We aim to find out the differences of these approaches for a realistic numerical setting based on the stimulation of the auditory cortex. The results obtained suggest, among other things, that GAP and GAP/PEM are sufficiently accurate for the practical application of tES and parallel tES/EEG, respectively. Differences between CEM and GAP were observed mainly in the skin compartment, where only CEM explains the heating effects characteristic to tES.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Research group: Inverse Problems, University of Münster
Contributors: Pursiainen, S., Agsten, B., Wagner, S., Wolters, C. H.
Pages: 37-44
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Neural Systems and Rehabilitation Engineering
Volume: 26
Issue number: 1
ISSN (Print): 1534-4320
Ratings: 
  • Scopus rating (2017): CiteScore 5.14 SJR 1.152 SNIP 2.165
Original language: English
ASJC Scopus subject areas: Neuroscience(all), Biomedical Engineering, Computer Science Applications
Keywords: Boundary conditions, Brain modeling, Complete electrode model (CEM), Computational modeling, Electric potential, Electrodes, Electroencephalography, Electroencephalography (EEG) electrode modeling, Finite element method (FEM)., Skin, Transcranial electrical stimulation (tES)
Source: Scopus
Source ID: 85030762392

Research output: Contribution to journalArticleScientificpeer-review

Bayes Forest: A data-intensive generator of morphological tree clones

Detailed and realistic tree form generators have numerous applications in ecology and forestry. For example, the varying morphology of trees contributes differently to formation of landscapes, natural habitats of species, and eco-physiological characteristics of the biosphere. Here, we present an algorithm for generating morphological tree "clones" based on the detailed reconstruction of the laser scanning data, statistical measure of similarity, and a plant growth model with simple stochastic rules. The algorithm is designed to produce tree forms, i.e., morphological clones, similar (and not identical) in respect to tree-level structure, but varying in fine-scale structural detail. Although we opted for certain choices in our algorithm, individual parts may vary depending on the application, making it a general adaptable pipeline. Namely, we showed that a specific multipurpose procedural stochastic growth model can be algorithmically adjusted to produce the morphological clones replicated from the target experimentally measured tree. For this, we developed a statistical measure of similarity (structural distance) between any given pair of trees, which allows for the comprehensive comparing of the tree morphologies by means of empirical distributions describing the geometrical and topological features of a tree. Finally, we developed a programmable interface to manipulate data required by the algorithm. Our algorithm can be used in a variety of applications for exploration of the morphological potential of the growth models (both theoretical and experimental), arising in all sectors of plant science research.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Mathematics, Research group: Inverse Problems, Department of Computer Science, Aalto University
Contributors: Potapov, I., Järvenpää, M., Åkerblom, M., Raumonen, P., Kaasalainen, M.
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: GigaScience
Volume: 6
Issue number: 10
Article number: gix079
ISSN (Print): 2047-217X
Ratings: 
  • Scopus rating (2017): CiteScore 6.81 SJR 5.022 SNIP 1.857
Original language: English
ASJC Scopus subject areas: Health Informatics, Computer Science Applications
Keywords: Empirical distributions, Large scale data, Morphological clone, Quantitative structure tree model, Stochastic data driven model, Terrestrial laser scanning
Electronic versions: 

Bibliographical note

EXT="Järvenpää, Marko"

Source: Scopus
Source ID: 85032857287

Research output: Contribution to journalArticleScientificpeer-review

Dynamic response to process disturbances—A comparison between TMB/SMB models in transient regime

The modelling and design of Simulated moving bed (SMB) processes is normally done using the True moving bed (TMB) approximation. Several studies show that average values obtained at cyclic steady state for SMB units approach the TMB unit at steady state and that this approach is better as the number of columns in the SMB increases. However, studies that evaluate this equivalence under dynamic conditions are scarce. The objective of this work is to perform an analysis of the transient behaviour of two SMB units, with four and eight columns, and compare the results with the ones obtained for a TMB unit. An analysis of the impact of operating variables on the processes performance parameters is performed. The results show that TMB/SMB equivalence is valid only for conditions that do not violate the regeneration/separation regions and that the transient behaviour of the four columns SMB can resemble more the TMB.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Univ Porto, Universidade do Porto, Fac Med, Dept Med Imaging
Contributors: Nogueira, I. B., Ribeiro, A. M., Rodrigues, A. E., Loureiro, J. M.
Number of pages: 15
Pages: 230-244
Publication date: 2017
Peer-reviewed: Yes

Publication information

Journal: Computers and Chemical Engineering
Volume: 99
ISSN (Print): 0098-1354
Ratings: 
  • Scopus rating (2017): CiteScore 3.65 SJR 1.024 SNIP 1.639
Original language: English
ASJC Scopus subject areas: Chemical Engineering(all), Computer Science Applications
Keywords: Dynamic behaviour, Enantiomers separation, Simulated moving bed, True moving bed
Source: Scopus
Source ID: 85012284107

Research output: Contribution to journalArticleScientificpeer-review

Visual decision support for business ecosystem analysis

This study comparatively evaluates the effectiveness of three visualization methods (list, matrix, network) and the influence of data complexity, task type, and user characteristics on decision performance in the context of business ecosystem analysis. We pursue this objective using an exploratory study with 14 prototypical users (e.g. executives, analysts, investors, and policy makers). The results show that in low complexity contexts, decision performance between visual representations differ but not substantially. In high complexity contexts, however, decision performance suffers significantly if visual representations are not appropriately matched to task types. Our study makes several theoretical and practical contributions. Theoretically, we extend cognitive fit theory by investigating the impact of business ecosystem task type and complexity. Managerially, our study contributes to the relatively underexplored, but emerging area of the design of business ecosystem intelligence tools and presentation of business ecosystem data for the purpose of decision making. We conclude with future research opportunities.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Mathematics, Research group: MAT Intelligent Information Systems Laboratory, Tennenbaum Institute & School of Interactive Computing Georgia Institute of Technology 85 Fifth Street NW Atlanta, VTT Technical Research Centre of Finland, mediaX and H*STAR Stanford University Stanford
Contributors: Basole, R. C., Huhtamäki, J., Still, K., Russell, M. G.
Number of pages: 12
Pages: 271-282
Publication date: 15 Dec 2016
Peer-reviewed: Yes

Publication information

Journal: Expert Systems with Applications
Volume: 65
ISSN (Print): 0957-4174
Ratings: 
  • Scopus rating (2016): CiteScore 4.7 SJR 1.343 SNIP 2.514
Original language: English
ASJC Scopus subject areas: Engineering(all), Computer Science Applications, Artificial Intelligence
Keywords: Business ecosystem, Cognitive fit theory, Data complexity, Decision support, Information visualization
Source: Scopus
Source ID: 84984633268

Research output: Contribution to journalArticleScientificpeer-review

Improving the delivery cycle: A multiple-case study of the toolchains in Finnish software intensive enterprises

Context: Software companies seek to gain benefit from agile development approaches in order to meet evolving market needs without losing their innovative edge. Agile practices emphasize frequent releases with the help of an automated toolchain from code to delivery. Objective: We investigate, which tools are used in software delivery, what are the reasons omitting certain parts of the toolchain and what implications toolchains have on how rapidly software gets delivered to customers. Method: We present a multiple-case study of the toolchains currently in use in Finnish software-intensive organizations interested in improving their delivery frequency. We conducted qualitative semi-structured interviews in 18 case organizations from various software domains. The interviewees were key representatives of their organization, considering delivery activities. Results: Commodity tools, such as version control and continuous integration, were used in almost every organization. Modestly used tools, such as UI testing and performance testing, were more distinctly missing from some organizations. Uncommon tools, such as artifact repository and acceptance testing, were used only in a minority of the organizations. Tool usage is affected by the state of current workflows, manual work and relevancy of tools. Organizations whose toolchains were more automated and contained fewer manual steps were able to deploy software more rapidly. Conclusions: There is variety in the need for tool support in different development steps as there are domain-specific differences in the goals of the case organizations. Still, a well-founded toolchain supports speedy delivery of new software.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Pervasive Computing, Research area: Software engineering, University of Helsinki, Aalto University
Contributors: Mäkinen, S., Leppänen, M., Kilamo, T., Mattila, A., Laukkanen, E., Pagels, M., Männistö, T.
Number of pages: 13
Pages: 1339-1351
Publication date: 1 Dec 2016
Peer-reviewed: Yes

Publication information

Journal: Information and Software Technology
Volume: 80
ISSN (Print): 0950-5849
Ratings: 
  • Scopus rating (2016): CiteScore 3.61 SJR 0.801 SNIP 2.568
Original language: English
ASJC Scopus subject areas: Software, Information Systems, Computer Science Applications
Keywords: Agile software development, Continuous delivery, Continuous deployment, Deployment pipeline, Software development tools
Source: Scopus
Source ID: 84988001567

Research output: Contribution to journalArticleScientificpeer-review

SamExploreR: Exploring reproducibility and robustness of RNA-seq results based on SAM files

Motivation: Data from RNA-seq experiments provide us with many new possibilities to gain insights into biological and disease mechanisms of cellular functioning. However, the reproducibility and robustness of RNA-seq data analysis results is often unclear. This is in part attributed to the two counter acting goals of (i) a cost efficient and (ii) an optimal experimental design leading to a compromise, e.g. in the sequencing depth of experiments. Results: We introduce an R package called samExploreR that allows the subsampling (m out of n bootstraping) of short-reads based on SAM files facilitating the investigation of sequencing depth related questions for the experimental design. Overall, this provides a systematic way for exploring the reproducibility and robustness of general RNA-seq studies. We exemplify the usage of samExploreR by studying the influence of the sequencing depth and the annotation on the identification of differentially expressed genes.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, BioMediTech, Queen's University, Belfast, Northern Ireland, University of Arkansas for Medical Sciences, Nankai University
Contributors: Stupnikov, A., Tripathi, S., De Matos Simoes, R., McArt, D., Salto-Tellez, M., Glazko, G., Dehmer, M., Emmert-Streib, F.
Number of pages: 3
Pages: 3345-3347
Publication date: 1 Nov 2016
Peer-reviewed: Yes

Publication information

Journal: Bioinformatics
Volume: 32
Issue number: 21
ISSN (Print): 1367-4803
Ratings: 
  • Scopus rating (2016): CiteScore 6.42 SJR 5.21 SNIP 2.336
Original language: English
ASJC Scopus subject areas: Statistics and Probability, Medicine(all), Biochemistry, Molecular Biology, Computer Science Applications, Computational Theory and Mathematics, Computational Mathematics
Source: Scopus
Source ID: 84994666672

Research output: Contribution to journalArticleScientificpeer-review

Development of an England-wide indoor overheating and air pollution model using artificial neural networks

With the UK climate projected to warm in future decades, there is an increased research focus on the risks of indoor overheating. Energy-efficient building adaptations may modify a buildings risk of overheating and the infiltration of air pollution from outdoor sources. This paper presents the development of a national model of indoor overheating and air pollution, capable of modelling the existing and future building stocks, along with changes to the climate, outdoor air pollution levels, and occupant behaviour. The model presented is based on a large number of EnergyPlus simulations run in parallel. A metamodelling approach is used to create a model that estimates the indoor overheating and air pollution risks for the English housing stock. The performance of neural networks (NNs) is compared to a support vector regression (SVR) algorithm when forming the metamodel. NNs are shown to give almost a 50% better overall performance than SVR.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: University College London, London School of Hygiene and Tropical Medicine, Public Health England
Contributors: Symonds, P., Taylor, J., Chalabi, Z., Mavrogianni, A., Davies, M., Hamilton, I., Vardoulakis, S., Heaviside, C., Macintyre, H.
Number of pages: 14
Pages: 606-619
Publication date: 1 Nov 2016
Peer-reviewed: Yes

Publication information

Journal: JOURNAL OF BUILDING PERFORMANCE SIMULATION
Volume: 9
Issue number: 6
ISSN (Print): 1940-1493
Ratings: 
  • Scopus rating (2016): CiteScore 1.96 SJR 0.877 SNIP 1.399
Original language: English
ASJC Scopus subject areas: Architecture , Building and Construction, Modelling and Simulation, Computer Science Applications
Keywords: indoor air pollution, machine learning, metamodelling, neural networks, overheating, stock modelling
Source: Scopus
Source ID: 84963632445

Research output: Contribution to journalArticleScientificpeer-review

Image interpolation based on non-local geometric similarities and directional gradients

Image interpolation offers an efficient way to compose a high-resolution (HR) image from the observed low-resolution (LR) image. Advanced interpolation techniques design the interpolation weighting coefficients by solving a minimum mean-square-error (MMSE) problem in which the local geometric similarity is often considered. However, using local geometric similarities cannot usually make the MMSE-based interpolation as reliable as expected. To solve this problem, we propose a robust interpolation scheme by using the nonlocal geometric similarities to construct the HR image. In our proposed method, the MMSE-based interpolation weighting coefficients are generated by solving a regularized least squares problem that is built upon a number of dual-reference patches drawn from the given LR image and regularized by the directional gradients of these patches. Experimental results demonstrate that our proposed method offers a remarkable quality improvement as compared to some state-of-the-art methods, both objectively and subjectively.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Video, University of Electronic Science and Technology of China
Contributors: Zhu, S., Zeng, B., Zeng, L., Gabbouj, M.
Number of pages: 13
Pages: 1707-1719
Publication date: 1 Sep 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Multimedia
Volume: 18
Issue number: 9
ISSN (Print): 1520-9210
Ratings: 
  • Scopus rating (2016): CiteScore 5.4 SJR 1.298 SNIP 2.536
Original language: English
ASJC Scopus subject areas: Signal Processing, Media Technology, Computer Science Applications, Electrical and Electronic Engineering
Keywords: Directional gradient, geometric similarity, image interpolation, minimum mean square error (MMSE)
Source: Scopus
Source ID: 84983409176

Research output: Contribution to journalArticleScientificpeer-review

Full-duplex mobile device: Pushing the limits

In this article, we address the challenges of transmitter-receiver isolation in mobile full-duplex devices, building on shared-antenna-based transceiver architecture. First, self-adaptive analog RF cancellation circuitry is required, since the ability to track time-varying self-interference coupling characteristics is of utmost importance in mobile devices. In addition, novel adaptive nonlinear DSP methods are also required for final self-interference suppression at digital baseband, since mobile-scale devices typically operate under highly nonlinear low-cost RF components. In addition to describing the above kind of advanced circuit and signal processing solutions, comprehensive RF measurement results from a complete demonstrator implementation are also provided, evidencing beyond 40 dB of active RF cancellation over an 80 MHz waveform bandwidth with a highly nonlinear transmitter power amplifier. Measured examples also demonstrate the good self-healing characteristics of the developed control loop against fast changes in the coupling channel. Furthermore, when complemented by nonlinear digital cancellation processing, the residual self-interference level is pushed down to the noise floor of the demonstration system, despite the harsh nonlinear nature of the self-interference. These findings indicate that deploying the full-duplex principle can indeed also be feasible in mobile devices, and thus be one potential technology in, for example, 5G and beyond radio systems.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Intel Corporation
Contributors: Korpi, D., Tamminen, J., Turunen, M., Huusari, T., Choi, Y. S., Anttila, L., Talwar, S., Valkama, M.
Number of pages: 8
Pages: 80-87
Publication date: 1 Sep 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 54
Issue number: 9
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2016): CiteScore 10.66 SJR 2.298 SNIP 5.041
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 84991056293

Research output: Contribution to journalArticleScientificpeer-review

Toward trusted, social-aware D2D connectivity: Bridging across the technology and sociality realms

Driven by the unprecedented increase of mobile data traffic, D2D communications technology is rapidly moving into the mainstream of the 5G networking landscape. While D2D connectivity originally emerged as a technology enabler for public safety services, it is likely to remain at the heart of the 5G ecosystem by spawning a wide diversity of proximate applications and services. In this work, we argue that the widespread adoption of the direct communications paradigm is unlikely without embracing the concepts of trust and social-aware cooperation between end users and network operators. However, such adoption remains conditional on identifying adequate incentives that engage humans and their connected devices in a plethora of collective activities. To this end, the mission of our research is to advance the vision of social-aware and trusted D2D connectivity, as well as to facilitate its further adoption. We begin by reviewing the various types of underlying incentives with the emphasis on sociality and trust, discuss these factors specifically for humans and for networked devices (machines), and also propose a novel framework allowing construction of much needed incentive-aware D2D applications. Our supportive system-level performance evaluations suggest that trusted and social-aware direct connectivity has the potential to decisively augment network performance. We conclude by outlining the future perspectives of its development across the research and standardization sectors.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Department of Pervasive Computing, Research group: Emerging Technologies for Nano-Bio-Info-Cogno, Universita degli Studi di Reggio Calabria, Ericsson Research and Wireless
Contributors: Ometov, A., Orsino, A., Militano, L., Moltchanov, D., Araniti, G., Olshannikova, E., Fodor, G., Andreev, S., Olsson, T., Iera, A., Torsner, J., Koucheryavy, Y., Mikkonen, T.
Number of pages: 9
Pages: 103-111
Publication date: 1 Aug 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 23
Issue number: 4
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2016): CiteScore 9.15 SJR 2.082 SNIP 3.875
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 84986197866

Research output: Contribution to journalArticleScientificpeer-review

Exploring synergy between communications, caching, and computing in 5G-grade deployments

Decisive progress in 5G mobile technology, fueled by a rapid proliferation of computation- hungry and delay-sensitive services, puts economic pressure on the research community to rethink the fundamentals of underlying networking architectures. Along these lines, the first half of this article offers a first-hand tutorial on the most recent advances in content-centric networking, emerging user applications, as well as enabling system architectures. We establish that while significant progress has been made along the individual vectors of communications, caching, and computing, together with some promising steps in proposing hybrid functionalities, the ultimate synergy behind a fully integrated solution is not nearly well understood. Against this background, the second half of this work carefully brings into perspective additional important factors, such as user mobility patterns, aggressive application requirements, and associated operator deployment capabilities, to conduct comprehensive system-level analysis. Furthermore, supported by a full-fledged practical trial on a live cellular network, our systematic findings reveal the most dominant factors in converged 5G-grade communications, caching, and computing layouts, as well as indicate the natural optimization points for system operators to leverage the maximum available benefits.

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, Brno University of Technology, Carleton University
Contributors: Andreev, S., Galinina, O., Pyattaev, A., Hosek, J., Masek, P., Yanikomeroglu, H., Koucheryavy, Y.
Number of pages: 10
Pages: 60-69
Publication date: 1 Aug 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 54
Issue number: 8
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2016): CiteScore 10.66 SJR 2.298 SNIP 5.041
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Computer Networks and Communications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 84982290651

Research output: Contribution to journalArticleScientificpeer-review

Robust data reconciliation of combustion variables in multi-fuel fired industrial boilers

This paper introduces an application of simultaneous nonlinear data reconciliation and gross error detection for power plants utilizing a complex but computationally light first principle combustion model. Element and energy balances and robust techniques introduce nonlinearity and the consequent optimization problem is solved using nonlinear optimization. Data reconciliation improves estimation of process variables and enables improved sensor quality control and identification of process anomalies. The approach was applied to an industrial 200 MWth fluidized bed boiler combusting wood, peat, bark, and slurry. The results indicate that the approach is valid and is able to perform in various process conditions. As the combustion model is generic, the method is applicable in any boiler environment.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Automation Science and Engineering, Research area: Dynamic Systems, Research area: Measurement Technology and Process Control, Indmeas Ltd.
Contributors: Korpela, T., Suominen, O., Majanne, Y., Laukkanen, V., Lautala, P.
Number of pages: 15
Pages: 101-115
Publication date: 21 Jul 2016
Peer-reviewed: Yes

Publication information

Journal: Control Engineering Practice
Volume: 55
ISSN (Print): 0967-0661
Ratings: 
  • Scopus rating (2016): CiteScore 3.42 SJR 1.076 SNIP 2.087
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Electrical and Electronic Engineering, Applied Mathematics, Computer Science Applications
Keywords: Data reconciliation, Diagnostics, Estimation, Gross error detection, Monitoring, Power plant
Source: Scopus
Source ID: 84978710819

Research output: Contribution to journalArticleScientificpeer-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 5.37 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

Visual Voice Activity Detection in the Wild

The visual voice activity detection (V-VAD) problem in unconstrained environments is investigated in this paper. A novel method for V-VAD in the wild, exploiting local shape and motion information appearing at spatiotemporal locations of interest for facial video segment description and the bag of words model for facial video segment representation, is proposed. Facial video segment classification is subsequently performed using the state-of-The-Art classification algorithms. Experimental results on one publicly available V-VAD dataset denote the effectiveness of the proposed method, since it achieves better generalization performance in unseen users, when compared to the recently proposed state-of-The-Art methods. Additional results on a new unconstrained dataset provide evidence that the proposed method can be effective even in such cases in which any other existing method fails.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Aristotle University of Thessaloniki
Contributors: Patrona, F., Iosifidis, A., Tefas, A., Nikolaidis, N., Pitas, I.
Number of pages: 11
Pages: 967-977
Publication date: 1 Jun 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Multimedia
Volume: 18
Issue number: 6
ISSN (Print): 1520-9210
Ratings: 
  • Scopus rating (2016): CiteScore 5.4 SJR 1.298 SNIP 2.536
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Signal Processing, Media Technology, Computer Science Applications
Keywords: Action Recognition, Bag of Words model, Voice Activity Detection in the wild
Source: Scopus
Source ID: 84971281783

Research output: Contribution to journalArticleScientificpeer-review

Linear accelerometers and rate gyros for rotary joint angle estimation of heavy-duty mobile manipulators using forward kinematic modeling

A gravity-referenced joint angle estimation approach is proposed for multiple-degree-of-freedom hydraulic manipulators. The approach is built solely upon easy-to-install linear accelerometers and angular rate gyroscopes to avoid physical contact to rotary joint mechanisms and the use of in-axis sensors. As a significant novelty, a comprehensive kinematics model for linear accelerations acting on the accelerometers during motion is associated with the well-known principles of complementary sensor fusion for the first time, which provides a practical solution for using the force of gravity as an angular reference while in fast motion. In experiments with a serial-link manipulator of a multiton off-road forestry vehicle, gyro-aided sensor fusion employing the kinematics model achieved a joint angle sensing error of less than ±1°, which translated to a centimeter end-effector positioning accuracy. This can be considered a significant result in view of the vibrations oscillating through the manipulator structure, coupled linear accelerations of linkage motion, and nonstatic interaction between the vehicle base and the terrain.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: MMDM, Department of Intelligent Hydraulics and Automation, Research group: Mobile manipulation, Research area: Information Technology for Biology and Health, Research area: Intelligence in Machines, Research area: Signal and Information Processing
Contributors: Vihonen, J., Honkakorpi, J., Tuominen, J., Mattila, J., Visa, A.
Number of pages: 10
Pages: 1765-1774
Publication date: 1 Jun 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE - ASME Transactions on Mechatronics
Volume: 21
Issue number: 3
ISSN (Print): 1083-4435
Ratings: 
  • Scopus rating (2016): CiteScore 5.22 SJR 1.511 SNIP 2.548
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Computer Science Applications
Keywords: Kinematics, Manipulators, Microelectromechanical devices
Source: Scopus
Source ID: 84970024956

Research output: Contribution to journalArticleScientificpeer-review

Characterizing rate limiting steps in transcription from RNA production times in live cells

Motivation: Single-molecule measurements of live Escherichia coli transcription dynamics suggest that this process ranges from sub- to super-Poissonian, depending on the conditions and on the promoter. For its accurate quantification, we propose a model that accommodates all these settings, and statistical methods to estimate the model parameters and to select the relevant components. Results: The new methodology has improved accuracy and avoids overestimating the transcription rate due to finite measurement time, by exploiting unobserved data and by accounting for the effects of discrete sampling. First, we use Monte Carlo simulations of models based on measurements to show that the methods are reliable and offer substantial improvements over previous methods. Next, we apply the methods on measurements of transcription intervals of different promoters in live E. coli, and show that they produce significantly different results, both in low- and high-noise settings, and that, in the latter case, they even lead to qualitatively different results. Finally, we demonstrate that the methods can be generalized for other similar purposes, such as for estimating gene activation kinetics. In this case, the new methods allow quantifying the inducer uptake dynamics as opposed to just comparing them between cases, which was not previously possible. We expect this new methodology to be a valuable tool for functional analysis of cellular processes using single-molecule or single-event microscopy measurements in live cells.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research group: Laboratory of Biosystem Dynamics-LBD, Department of Signal Processing
Contributors: Häkkinen, A., Ribeiro, A. S.
Number of pages: 7
Pages: 1346-1352
Publication date: 1 May 2016
Peer-reviewed: Yes

Publication information

Journal: Bioinformatics
Volume: 32
Issue number: 9
ISSN (Print): 1367-4803
Ratings: 
  • Scopus rating (2016): CiteScore 6.42 SJR 5.21 SNIP 2.336
Original language: English
ASJC Scopus subject areas: Biochemistry, Molecular Biology, Computational Theory and Mathematics, Computer Science Applications, Computational Mathematics, Statistics and Probability
Source: Scopus
Source ID: 84966359423

Research output: Contribution to journalArticleScientificpeer-review

A unifying perspective on proximity-based cellular-assisted mobile social networking

Today, the rapid adoption of mobile social networking is changing how and where humans communicate. As a result, in recent years we have been increasingly moving from physical (e.g., face-to-face) to virtual interaction. However, there is also a new emerging category of social applications that take advantage of both worlds, that is, using virtual interaction to enhance physical interaction. This novel form of networking is enabled by D2D communication between/among the laptops, smartphones, and wearables of persons in proximity of each other. Unfortunately, it has remained limited by the fact that most people are simply not aware of the many potential virtual opportunities in their proximity at any given time. This is a result of the very real digital privacy and security concerns surrounding direct communication between stranger devices. Fortunately, these concerns can be mitigated with the help of a centralized trusted entity, such as a cellular service provider, which can not only authenticate and protect the privacy of devices involved into D2D communication, but also facilitate the discovery of device capabilities and their available content. This article offers an extensive research summary behind this type of cellular-assisted D2D communication, detailing the enabling technology and its implementation, relevant usage scenarios, security challenges, and user experience observations from large-scale deployments.

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, Department of Pervasive Computing, Research area: Software engineering
Contributors: Andreev, S., Hosek, J., Olsson, T., Johnsson, K., Pyattaev, A., Ometov, A., Olshannikova, E., Gerasimenko, M., Masek, P., Koucheryavy, Y., Mikkonen, T.
Number of pages: 9
Pages: 108-116
Publication date: 1 Apr 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 54
Issue number: 4
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2016): CiteScore 10.66 SJR 2.298 SNIP 5.041
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computer Networks and Communications
Source: Scopus
Source ID: 84964277259

Research output: Contribution to journalArticleScientificpeer-review

On feasibility of 5G-grade dedicated RF charging technology for wireless-powered wearables

For decades, wireless energy transfer and harvesting received focused attention in the research community, but with limited practical applications. Recently, with the development of fifth-generation (5G) mobile technology, the concept of dedicated radio-frequency (RF) charging promises to support the growing market of wearable devices. In this work we shed light on the potential of wireless RF power transfer by elaborating upon feasible system parameters and architecture, emphasizing the basic tradeoffs behind omni-directional and directional out-of-band energy transmission, providing system- level performance evaluation, and discussing open challenges on the way to sustainable wireless- powered wearables. The key aspects highlighted in this article include system operation choices, user mobility effects, impact of network and user densities, and regulatory issues. Ultimately, our research aims to facilitate the integration of wireless RF charging technology into the emerging 5G ecosystem.

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 Manitoba, Univ of Oulu
Contributors: Galinina, O., Tabassum, H., Mikhaylov, K., Andreev, S., Hossain, E., Koucheryavy, Y.
Number of pages: 10
Pages: 28-37
Publication date: 1 Apr 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 23
Issue number: 2
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2016): CiteScore 9.15 SJR 2.082 SNIP 3.875
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Electrical and Electronic Engineering
Source: Scopus
Source ID: 84968750633

Research output: Contribution to journalArticleScientificpeer-review

Detection of bubbles as concentric circular arrangements

The paper proposes a method for the detection of bubble-like transparent objects in a liquid. The detection problem is non-trivial since bubble appearance varies considerably due to different lighting conditions causing contrast reversal and multiple interreflections. We formulate the problem as the detection of concentric circular arrangements (CCA). The CCAs are recovered in a hypothesize-optimize-verify framework. The hypothesis generation is based on sampling from the partially linked components of the non-maximum suppressed responses of oriented ridge filters, and is followed by the CCA parameter estimation. Parameter optimization is carried out by minimizing a novel cost-function. The performance was tested on gas dispersion images of pulp suspension and oil dispersion images. The mean error of gas/oil volume estimation was used as a performance criterion due to the fact that the main goal of the applications driving the research was the bubble volume estimation. The method achieved 28 and 13 % of gas and oil volume estimation errors correspondingly outperforming the OpenCV Circular Hough Transform in both cases and the WaldBoost detector in gas volume estimation.

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), Machine Vision and Pattern Recognition Laboratory, Lappeenranta University of Technology, Computer Vision Group, Czech Technical University in Prague, Monash University Malaysia
Contributors: Strokina, N., Matas, J., Eerola, T., Lensu, L., Kälviäinen, H.
Number of pages: 10
Pages: 387-396
Publication date: Apr 2016
Peer-reviewed: Yes
Early online date: 10 Feb 2016

Publication information

Journal: Machine Vision and Applications
Volume: 27
Issue number: 3
ISSN (Print): 0932-8092
Ratings: 
  • Scopus rating (2016): CiteScore 2.46 SJR 0.741 SNIP 1.433
Original language: English
ASJC Scopus subject areas: Hardware and Architecture, Computer Vision and Pattern Recognition, Software, Computer Science Applications
Keywords: Bubble detection, Circular arrangements, Image processing, Machine vision, Object segmentation
Source: Scopus
Source ID: 84957656160

Research output: Contribution to journalArticleScientificpeer-review

Digital predistortion for mitigating spurious emissions in spectrally agile radios

Spectrally non-contiguous transmissions pose serious transceiver design challenges due to the nonlinear PA. When two or more non-contiguous carriers with close proximity are amplified by the same PA, spurious emissions inside or in the vicinity of the transmitter RF band are created. These spurious emissions may violate emission limits or otherwise compromise network coverage and reliability. Lowering the transmit power is a straightforward remedy, but it will reduce throughput, coverage, and power efficiency of the device. To improve linearity without sacrificing performance, several DPD techniques have recently been proposed to target the spurious emissions explicitly. These techniques are designed to minimize the computational and hardware complexity of DPD, thus making them better suited for mobile terminals and other lowcost devices. In this article, these recent advances in DPD for non-contiguous transmission scenarios are discussed, with a focus on mitigating the spurious emissions in the concrete example case of non-contiguous dual-carrier transmission. The techniques are compared to more traditional DPD approaches in terms of their computational and hardware complexities, as well as linearization performance.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Qualcomm Inc., Wireless Innovation Laboratory at Worcester Polytechnic Institute
Contributors: Abdelaziz, M., Fu, Z., Anttila, L., Wyglinski, A. M., Valkama, M.
Number of pages: 10
Pages: 60-69
Publication date: 1 Mar 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 54
Issue number: 3
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2016): CiteScore 10.66 SJR 2.298 SNIP 5.041
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computer Networks and Communications
Source: Scopus
Source ID: 84963776001

Research output: Contribution to journalArticleScientificpeer-review

Highly dynamic spectrum management within licensed shared access regulatory framework

Historical fragmentation in spectrum access models accentuates the need for novel concepts that allow for efficient sharing of already available but underutilized spectrum. The emerging LSA regulatory framework is expected to enable more advanced spectrum sharing between a limited number of users while guaranteeing their much needed interference protection. However, the ultimate benefits of LSA may in practice be constrained by space-time availability of the LSA bands. Hence, more dynamic LSA spectrum management is required to leverage such realtime variability and sustain reliability when, for example, the original spectrum user suddenly revokes the previously granted frequency bands as they are required again. In this article, we maintain the vision of highly dynamic LSA architecture and rigorously study its future potential, from reviewing market opportunities and discussing available technology implementations to conducting performance evaluation of LSA dynamics and outlining the standardization landscape. Our investigations are based on a comprehensive system-level evaluation framework, which has been specifically designed to assess highly dynamic LSA deployments.

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: Ponomarenko-Timofeev, A., Pyattaev, A., Andreev, S., Koucheryavy, Y., Mueck, M., Karls, I.
Number of pages: 10
Pages: 100-109
Publication date: 1 Mar 2016
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 54
Issue number: 3
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2016): CiteScore 10.66 SJR 2.298 SNIP 5.041
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computer Networks and Communications

Bibliographical note

INT=elt,"Ponomarenko-Timofeev, Aleksei"

Source: Scopus
Source ID: 84963721319

Research output: Contribution to journalArticleScientificpeer-review

First-principles data set of 45,892 isolated and cation-coordinated conformers of 20 proteinogenic amino acids

We present a structural data set of the 20 proteinogenic amino acids and their amino-methylated and acetylated (capped) dipeptides. Different protonation states of the backbone (uncharged and zwitterionic) were considered for the amino acids as well as varied side chain protonation states. Furthermore, we studied amino acids and dipeptides in complex with divalent cations (Ca2+, Ba2+, Sr2+, Cd2+, Pb2+, and Hg2+). The database covers the conformational hierarchies of 280 systems in a wide relative energy range of up to 4 eV (390 kJ/mol), summing up to a total of 45,892 stationary points on the respective potential-energy surfaces. All systems were calculated on equal first-principles footing, applying density-functional theory in the generalized gradient approximation corrected for long-range van der Waals interactions. We show good agreement to available experimental data for gas-phase ion affinities. Our curated data can be utilized, for example, for a wide comparison across chemical space of the building blocks of life, for the parametrization of protein force fields, and for the calculation of reference spectra for biophysical applications.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Physics, Fritz Haber Institute of the Max Planck Society, COMP Centre of Excellence, Department of Applied Physics, Aalto University, Aalto University, Duke University
Contributors: Ropo, M., Schneider, M., Baldauf, C., Blum, V.
Publication date: 16 Feb 2016
Peer-reviewed: Yes

Publication information

Journal: Scientific Data
Volume: 3
Article number: 160009
ISSN (Print): 2052-4463
Ratings: 
  • Scopus rating (2016): CiteScore 4.8 SJR 3.261 SNIP 2.208
Original language: English
ASJC Scopus subject areas: Education, Library and Information Sciences, Computer Science Applications, Information Systems, Statistics, Probability and Uncertainty, Statistics and Probability
Source: Scopus
Source ID: 84961184519

Research output: Contribution to journalArticleScientificpeer-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 7.14 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

Still image/video frame lossy compression providing a desired visual quality

The problem of how to automatically provide a desired (required) visual quality in lossy compression of still images and video frames is considered in this paper. The quality can be measured based on different conventional and visual quality metrics. In this paper, we mainly employ human visual system (HVS) based metrics PSNR-HVS-M and MSSIM since both of them take into account several important peculiarities of HVS. To provide a desired visual quality with high accuracy, iterative image compression procedures are proposed and analyzed. An experimental study is performed for a large number of grayscale test images. We demonstrate that there exist several coders for which the number of iterations can be essentially decreased using a reasonable selection of the starting value and the variation interval for the parameter controlling compression (PCC). PCC values attained at the end of the iterative procedure may heavily depend upon the coder used and the complexity of the image. Similarly, the compression ratio also considerably depends on the above factors. We show that for some modern coders that take HVS into consideration it is possible to give practical recommendations on setting a fixed PCC to provide a desired visual quality in a non-iterative manner. The case when original images are corrupted by visible noise is also briefly studied.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Computational Imaging-CI, National Aerospace University
Contributors: Zemliachenko, A., Lukin, V., Ponomarenko, N., Egiazarian, K., Astola, J.
Pages: 697-718
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Multidimensional Systems and Signal Processing
Volume: 27
Issue number: 3
ISSN (Print): 0923-6082
Ratings: 
  • Scopus rating (2016): CiteScore 1.47 SJR 0.424 SNIP 1.109
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Information Systems, Signal Processing, Software, Artificial Intelligence, Hardware and Architecture, Applied Mathematics
Keywords: Compression ratio, Lossy compression, Required quality, Visual quality metrics
Source: Scopus
Source ID: 84930357751

Research output: Contribution to journalArticleScientificpeer-review

Digital storytelling promoting twenty-first century skills and student engagement

This article presents results on how students became engaged and motivated when using digital storytelling in knowledge creation in Finland, Greece and California. The theoretical framework is based on sociocultural theories. Learning is seen as a result of dialogical interactions between people, substances and artefacts. This approach has been used in the creation of the Global Sharing Pedagogy (GSP) model for the empirical study of student levels of engagement in learning twenty-first century skills. This model presents a set of conceptual mediators for student-driven knowledge creation, collaboration, networking and digital literacy. Data from 319 students were collected using follow-up questionnaires after the digital storytelling project. Descriptive statistical methods, correlations, analysis of variance and regression analysis were used. The mediators of the GSP model strongly predicted student motivation and enthusiasm as well as their learning outcomes. The digital storytelling project, using the technological platform Mobile Video Experience (MoViE), was very successful in teaching twenty-first century skills.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Pori Department, University of Helsinki
Contributors: Niemi, H., Multisilta, J.
Pages: 451-468
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Technology, Pedagogy and Education
Volume: 25
Issue number: 4
ISSN (Print): 1475-939X
Ratings: 
  • Scopus rating (2016): CiteScore 1.4 SJR 0.906 SNIP 1.557
Original language: English
ASJC Scopus subject areas: Education, Communication, Computer Science Applications, Information Systems
Keywords: engagement, learning, motivation, twenty-first century skills
Source: Scopus
Source ID: 84939476760

Research output: Contribution to journalArticleScientificpeer-review

HTML5-based mobile agents for Web-of-Things

Systems and services utilizing Internet-of-Things can benefit from dynamically updated software in a significant way. In this paper we show how the most advanced variant of moving code, mobile agents, can be used for operating and managing Internet-connected systems composed of gadgets, sensors and actuators. We believe that the use of mobile agents brings several benefits, for example, mobile agents help to reduce the network load, overcome network latency, and encapsulate protocols. In addition, they can perform autonomous tasks that would otherwise require extensive configuration. The need for moving agents is even more significant if the applications and other factors of the over experience should follow the user to new contexts. When multiple agents are used to provide the user with services, some mechanisms to manage the agents are needed. In the context of Internet-of-Things such management should reflect the physical spaces and other relevant contexts. In this paper we describe the technical solutions used in implementation of the mobile agents, describe two proof concepts and we also compare our solution to related work. We also describe our visions of the future work.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Pervasive Computing, Research area: Software engineering
Contributors: Voutilainen, J. P., Mattila, A. L., Systä, K., Mikkonen, T.
Number of pages: 9
Pages: 43-51
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Informatica
Volume: 40
Issue number: 1
ISSN (Print): 0350-5596
Ratings: 
  • Scopus rating (2016): CiteScore 0.54 SJR 0.136 SNIP 0.461
Original language: English
ASJC Scopus subject areas: Computer Science Applications, Software, Artificial Intelligence, Theoretical Computer Science
Keywords: Html5, Internet-of-things, Javascript, Mobile agents, Web applications, Web-of-things
Source: Scopus
Source ID: 84963719558

Research output: Contribution to journalArticleScientificpeer-review

Brownfield Process: A method for modular product family development aiming for product configuration

Modularisation, product platforms, product families and product configuration are efficient product structuring tactics in mass customisation. Industry needs descriptions of how the engineering should be done in this context. We suggest that key engineering concepts in this field are partitioning logic, set of modules, interfaces, architecture and configuration knowledge. A literature review reveals that methods consider these concepts partly or with different combinations, but considering all of them is rare. Therefore, a design method known as the Brownfield Process is presented. The method is applied to an industrial case in which the aim was rationalisation of existing product variety towards a modular product family that enables product configuration. We suggest that the method is valuable in cases with similar goals.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research area: Design, Development and LCM, Department of Mechanical Engineering and Industrial Systems
Contributors: Pakkanen, J., Juuti, T., Lehtonen, T.
Number of pages: 32
Pages: 210-241
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: DESIGN STUDIES
Volume: 45B
ISSN (Print): 0142-694X
Ratings: 
  • Scopus rating (2016): CiteScore 3.3 SJR 1.32 SNIP 2.622
Original language: English
ASJC Scopus subject areas: Engineering(all), Architecture , Computer Science Applications, Artificial Intelligence, Social Sciences(all), Arts and Humanities (miscellaneous)
Keywords: Design method, Design process, Engineering design, Product design, Product development
Electronic versions: 
Source: Scopus
Source ID: 84967235654

Research output: Contribution to journalArticleScientificpeer-review

Metrics for polyphonic sound event detection

This paper presents and discusses various metrics proposed for evaluation of polyphonic sound event detection systems used in realistic situations where there are typically multiple sound sources active simultaneously. The system output in this case contains overlapping events, marked as multiple sounds detected as being active at the same time. The polyphonic system output requires a suitable procedure for evaluation against a reference. Metrics from neighboring fields such as speech recognition and speaker diarization can be used, but they need to be partially redefined to deal with the overlapping events. We present a review of the most common metrics in the field and the way they are adapted and interpreted in the polyphonic case. We discuss segment-based and event-based definitions of each metric and explain the consequences of instance-based and class-based averaging using a case study. In parallel, we provide a toolbox containing implementations of presented metrics.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Audio research group
Contributors: Mesaros, A., Heittola, T., Virtanen, T.
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Applied Sciences
Volume: 6
Issue number: 6
Article number: 162
ISSN (Print): 2076-3417
Original language: English
ASJC Scopus subject areas: Fluid Flow and Transfer Processes, Process Chemistry and Technology, Computer Science Applications, Engineering(all), Materials Science(all), Instrumentation
Keywords: Audio content analysis, Audio signal processing, Computational auditory scene analysis, Evaluation of sound event detection, Everyday sounds, Pattern recognition, Polyphonic sound event detection, Sound events
Source: Scopus
Source ID: 84973574836

Research output: Contribution to journalArticleScientificpeer-review

Technoeconomical Analysis of Macrocell and Femtocell Based HetNet under Different Deployment Constraints

Ultradense deployment of small cells is being considered as one of the key flavors of the emerging 5G cellular networks to address the future data capacity challenges. A large share of these deployments will be indoor, as this is the arena where the majority of the data traffic is believed to originate from in the future. Indoor small cell solutions (e.g., femtocell or WiFi) are well positioned for delivering superior indoor coverage and capacity. However, due to relatively smaller coverage footprint compared to traditional macrocells, a very dense deployment of small cells will be needed in order to have a ubiquitous indoor coverage. Such dense deployment triggers cost and energy efficiency concerns for mobile operators. In this paper, we analyze and compare the technoeconomic performance of two deployment strategies: homogeneous macrocellular densification and heterogeneous macro-femto deployment strategy, from an indoor service provisioning perspective. Particularly, we analyze and contrast the performance of macro-femto based deployment, with varying femtocell market penetration rate and under different femtocell backhaul connectivity constraints, with that of homogeneous macrocellular densification. The results indicate superior performance of indoor femtocell based deployment as compared to macrocellular-only densification, due to better indoor coverage, radio channel conditions, and high degree of spatial reuse.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Wireless Communications and Positioning
Contributors: Yunas, S. F., Ansari, W. H., Valkama, M.
Publication date: 2016
Peer-reviewed: Yes

Publication information

Journal: Mobile Information Systems
Volume: 2016
Article number: 6927678
ISSN (Print): 1574-017X
Ratings: 
  • Scopus rating (2016): CiteScore 1.03 SJR 0.208 SNIP 0.635
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Computer Science Applications

Bibliographical note

INT=elt,"Ansari, Waqas H."

Source: Scopus
Source ID: 84985945396

Research output: Contribution to journalArticleScientificpeer-review

Energy cooperation for throughput optimization based on save-then-transmit protocol in wireless communication system

Green communication and energy saving have been a critical issue in modern wireless communication systems. The concepts of energy harvesting and energy transfer are recently receiving much attention in academic research field. In this paper, we study energy cooperation problems based on save-then-transmit protocol and propose two energy cooperation schemes for different system models: two-node communication model and three-node relay communication model. In both models, all of the nodes transmitting information have no fixed energy supplies and gain energy only via wireless energy harvesting from nature. Besides, these nodes also follow a save-then-transmit protocol. Namely, for each timeslot, a fraction (referred to as save-ratio) of time is devoted exclusively to energy harvesting while the remaining fraction is used for data transmission. In order to maximize the system throughput, energy transfer mechanism is introduced in our schemes, i.e., some nodes are permitted to share their harvested energy with other nodes by means of wireless energy transfer. Simulation results demonstrate that our proposed schemes can outperform both the schemes with half-allocate save-ratio and the schemes without energy transfer in terms of throughput performance, and also characterize the dependencies of system throughput, transferred energy, and save-ratio on energy harvesting rate.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Wireless Communications and Positioning (WICO), Chongqing Key Lab of Mobile Communication Technology, Chongqing University of Posts and Telecommunications
Contributors: Dai, C., Li, F., Renfors, M.
Publication date: 26 Dec 2015
Peer-reviewed: Yes

Publication information

Journal: Eurasip Journal on Wireless Communications and Networking
Volume: 2015
Issue number: 1
Article number: 119
ISSN (Print): 1687-1472
Ratings: 
  • Scopus rating (2015): CiteScore 0.96 SJR 0.362 SNIP 1.138
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Signal Processing, Computer Science Applications
Keywords: Energy harvesting, Energy transfer, Save-then-transmit protocol, Throughput optimization
Source: Scopus
Source ID: 84930207810

Research output: Contribution to journalArticleScientificpeer-review

Polynomial Input-Output Stability for Linear Systems

We introduce the concept of polynomial input-output stability for infinite-dimensional linear systems. We show that this stability type corresponds exactly to the recent notion of P-stability in the frequency domain. In addition, we show that on a Hilbert space a regular linear system whose system operator generates a polynomially stable semigroup is always polynomially input-output stable, and present additional conditions under which the system is input-output stable. The results are illustrated with an example of a polynomially input-output stable one-dimensional wave system.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Mathematics, Research group: MAT Mathematical and semantic modelling
Contributors: Paunonen, L., Laakkonen, P.
Number of pages: 6
Pages: 2797-2802
Publication date: 1 Oct 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Automatic Control
Volume: 60
Issue number: 10
ISSN (Print): 0018-9286
Ratings: 
  • Scopus rating (2015): CiteScore 5.08 SJR 4.285 SNIP 3.213
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Computer Science Applications
Keywords: Distributed parameter system, Stability
Source: Scopus
Source ID: 84942853446

Research output: Contribution to journalArticleScientificpeer-review

Analytical model for magnetic anisotropy of non-oriented steel sheets

Purpose - Recent investigations on magnetic properties of non-oriented (NO) steel sheets enhance the comprehension of the magnetic anisotropy behaviour of widely employed electrical sheets. The concept of energy/coenergy density can be employed to model these magnetic properties. However, it usually presents an implicit form which requires an iterative process. The purpose of this paper is to develop an analytical model to consider these magnetic properties with an explicit formulation in order to ease the computations. Design/methodology/approach - From rotational measurements, the anhysteretic curves are interpolated in order to extract the magnetic energy density for different directions and amplitudes of the magnetic flux density. Furthermore, the analytical representation of this energy is suggested based on statistical distribution which aims to minimize the intrinsic energy of the material. The model is finally validated by comparing measured and computed values of the magnetic field strength. Findings - The proposed model is based on an analytical formulation of the energy depending on the components of the magnetic flux density. This formulation is composed of three Gumbel distributions. Every functional parameters of energy density is formulated with only four parameters which are calculated by fitting the energy extracted from measurements. Finally, the proposed model is validated by comparing the computation and the measurements of 9 H loci for NO steel sheets at 10 Hz. The proposed analytical model shows good agreements with an average relative error of 27 per cent. Originality/value - The paper presents an original analytical method to model magnetic anisotropy for NO electrical sheets. With this analytical formulation, the determination of H does not require any iterative process as it is usually the case with this energy method coupled with implicit function. This method can be easily incorporated in finite element method since it does not require any extra iterative process.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Smart Energy Systems (SES), Aalto University
Contributors: Martin, F., Singh, D., Belahcen, A., Rasilo, P., Haavisto, A., Arkkio, A.
Number of pages: 14
Pages: 1475-1488
Publication date: 7 Sep 2015
Peer-reviewed: Yes

Publication information

Journal: COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering
Volume: 34
Issue number: 5
ISSN (Print): 0332-1649
Ratings: 
  • Scopus rating (2015): CiteScore 0.68 SJR 0.231 SNIP 0.554
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computational Theory and Mathematics, Applied Mathematics
Keywords: FEM, Ferromagnetic materials, Magnetic anisotropy, Soft magnetic materials
Source: Scopus
Source ID: 84941117731

Research output: Contribution to journalArticleScientificpeer-review

Estimation of additional losses due to random contacts at the edges of stator of an electrical machine

Purpose - Punching of the electrical sheets impair the insulation and make random galvanic contacts between the edges of the sheets. The purpose of this paper is to model the random galvanic contacts at the stator edges of 37 kW induction machine and estimate the additional losses due to these contacts. Design/methodology/approach - The presence of the surface current at the edges of sheets causes the discontinuity in the tangential component of the magnetic field. The surface boundary layer model which is based on this concept is implemented to model the galvanic contacts at the edges of the sheets. Finite element analysis based on magnetic vector potential was done and theoretical statistical study of the random conductivity at the stator edge was performed using brute force method. Findings - Finite element analysis validates the interlaminar current when galvanic contacts are present at the edges of electrical sheets. The case studies show that the rotor and stator losses increases with the thickness of the contacts. Statistical studies show that the mean value of total electromagnetic loss was increased by 7.7 percent due to random contacts at the edges of sheets. Originality/value - The novel approach for modeling the galvanic contacts at the stator edges of induction machine is discussed in this paper. The hypothesis of interlaminar current due to galvanic contacts is also validated using finite element simulation.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Smart Energy Systems (SES), Aalto University
Contributors: Shah, S. B., Rasilo, P., Belahcen, A., Arkkio, A.
Number of pages: 10
Pages: 1501-1510
Publication date: 7 Sep 2015
Peer-reviewed: Yes

Publication information

Journal: COMPEL: The International Journal for Computation and Mathematics in Electrical and Electronic Engineering
Volume: 34
Issue number: 5
ISSN (Print): 0332-1649
Ratings: 
  • Scopus rating (2015): CiteScore 0.68 SJR 0.231 SNIP 0.554
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computational Theory and Mathematics, Applied Mathematics
Keywords: Boundary conditions, Eddy current, Electrical conductivity, FEM, Magnetic vector potential
Source: Scopus
Source ID: 84941111680

Research output: Contribution to journalArticleScientificpeer-review

DropELM: Fast neural network regularization with Dropout and DropConnect

In this paper, we propose an extension of the Extreme Learning Machine algorithm for Single-hidden Layer Feedforward Neural network training that incorporates Dropout and DropConnect regularization in its optimization process. We show that both types of regularization lead to the same solution for the network output weights calculation, which is adopted by the proposed DropELM network. The proposed algorithm is able to exploit Dropout and DropConnect regularization, without computationally intensive iterative weight tuning. We show that the adoption of such a regularization approach can lead to better solutions for the network output weights. We incorporate the proposed regularization approach in several recently proposed ELM algorithms and show that their performance can be enhanced without requiring much additional computational cost.

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: 10
Pages: 57-66
Publication date: 25 Aug 2015
Peer-reviewed: Yes

Publication information

Journal: Neurocomputing
Volume: 162
ISSN (Print): 0925-2312
Ratings: 
  • Scopus rating (2015): CiteScore 3.18 SJR 0.981 SNIP 1.698
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Computer Science Applications, Cognitive Neuroscience
Keywords: DropConnect, Dropout, Extreme Learning Machine, Regularization, Single Hidden Layer Feedforward Networks
Source: Scopus
Source ID: 84929271496

Research output: Contribution to journalArticleScientificpeer-review

Distance-based human action recognition using optimized class representations

We study distance-based classification of human actions and introduce a new metric learning approach based on logistic discrimination for the determination of a low-dimensional feature space of increased discrimination power. We argue that for effective distance-based classification, both the optimal projection space and the optimal class representation should be determined. We qualitatively and quantitatively illustrate the superiority of the proposed approach to metric learning approaches employing the class mean for class representation. We also introduce extensions of the proposed metric learning approach to allow for richer class representations and to operate in arbitrary-dimensional Hilbert spaces for non-linear feature extraction and classification. Experimental results denote that the performance of the proposed distance-based classification schemes is comparable (or even better) to that of Support Vector Machine classifier (in both the linear and kernel cases) which is currently the standard choice for human action recognition.

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: 47-55
Publication date: 5 Aug 2015
Peer-reviewed: Yes

Publication information

Journal: Neurocomputing
Volume: 161
ISSN (Print): 0925-2312
Ratings: 
  • Scopus rating (2015): CiteScore 3.18 SJR 0.981 SNIP 1.698
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Computer Science Applications, Cognitive Neuroscience
Keywords: Distance-based classification, Optimized class representations
Source: Scopus
Source ID: 84929045315

Research output: Contribution to journalArticleScientificpeer-review

Stability-Guaranteed Force-Sensorless Contact Force/Motion Control of Heavy-Duty Hydraulic Manipulators

In this paper, a force-sensorless high-performance contact force/motion control approach is proposed for multiple-degree-of-freedom hydraulic manipulators. A rigorous stability proof for an entire hydraulic manipulator performing contact tasks is provided for the first time. The controller design for the manipulator is based on the recently introduced virtual decomposition control approach. As a significant novelty, the end-effector contact force is directly estimated from the manipulator's cylinder pressure data, which provides a practical solution for heavy-duty contact force control without engaging fragile force/torque sensors. In the experiments, the proposed controller achieved a force control accuracy of 4.1% at a desired contact force of 8000 N while in motion. This can be considered a significant result due to the hydraulic actuators' highly nonlinear behaviors, the coupled mechanical linkage dynamics, and the complex interaction dynamics between the manipulator and the environment.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Intelligent Hydraulics and Automation, Research group: Mobile manipulation, Field robotics for efficient work sites (FIRE)
Contributors: Koivumäki, J., Mattila, J.
Number of pages: 18
Pages: 918-935
Publication date: 1 Aug 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Robotics
Volume: 31
Issue number: 4
ISSN (Print): 1552-3098
Ratings: 
  • Scopus rating (2015): CiteScore 4.86 SJR 2.271 SNIP 2.772
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Computer Science Applications
Keywords: Contact force estimation, contact force/motion control, hydraulic manipulators, nonlinear model-based control, stability analysis, virtual decomposition control (VDC)

Research output: Contribution to journalArticleScientificpeer-review

Effective variable switching point predictive current control for ac low-voltage drives

This paper presents an effective model predictive current control scheme for induction machines driven by a three-level neutral point clamped inverter, called variable switching point predictive current control. Despite the fact that direct, enumeration-based model predictive control (MPC) strategies are very popular in the field of power electronics due to their numerous advantages such as design simplicity and straightforward implementation procedure, they carry two major drawbacks. These are the increased computational effort and the high ripples on the controlled variables, resulting in a limited applicability of such methods. The high ripples occur because in direct MPC algorithms the actuating variable can only be changed at the beginning of a sampling interval. A possible remedy for this would be to change the applied control input within the sampling interval, and thus to apply it for a shorter time than one sample. However, since such a solution would lead to an additional overhead which is crucial especially for multilevel inverters, a heuristic preselection of the optimal control action is adopted to keep the computational complexity at bay. Experimental results are provided to verify the potential advantages of the proposed strategy.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Smart Energy Systems (SES), Technische Universitat Munchen, National Technical University of Athens, Technische Hochschule Ingolstadt
Contributors: Stolze, P., Karamanakos, P., Kennel, R., Manias, S., Endisch, C.
Number of pages: 13
Pages: 1366-1378
Publication date: 3 Jul 2015
Peer-reviewed: Yes

Publication information

Journal: International Journal of Control
Volume: 88
Issue number: 7
ISSN (Print): 0020-7179
Ratings: 
  • Scopus rating (2015): CiteScore 2.56 SJR 1.397 SNIP 1.361
Original language: English
ASJC Scopus subject areas: Control and Systems Engineering, Computer Science Applications
Keywords: ac low-voltage drives, model predictive control (MPC), optimal control, three-level inverter, variable switching point
Source: Scopus
Source ID: 84930755978

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 3.3 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

A robust AMMI model for the analysis of genotype-by-environment data

Motivation: One of the most widely used models to analyse genotype-by-environment data is the additive main effects and multiplicative interaction (AMMI) model. Genotype-by-environment data resulting from multi-location trials are usually organized in two-way tables with genotypes in the rows and environments (location-year combinations) in the columns. The AMMI model applies singular value decomposition (SVD) to the residuals of a specific linear model, to decompose the genotype-by-environment interaction (GEI) into a sum of multiplicative terms. However, SVD, being a least squares method, is highly sensitive to contamination and the presence of even a single outlier, if extreme, may draw the leading principal component towards itself resulting in possible misinterpretations and in turn lead to bad practical decisions. Since, as in many other real-life studies the distribution of these data is usually not normal due to the presence of outlying observations, either resulting from measurement errors or sometimes from individual intrinsic characteristics, robust SVD methods have been suggested to help overcome this handicap. Results: We propose a robust generalization of the AMMI model (the R-AMMI model) that overcomes the fragility of its classical version when the data are contaminated. Here, robust statistical methods replace the classic ones to model, structure and analyse GEI. The performance of the robust extensions of the AMMI model is assessed through a Monte Carlo simulation study where several contamination schemes are considered. Applications to two real plant datasets are also presented to illustrate the benefits of the proposed methodology, which can be broadened to both animal and human genetics studies. Availability and implementation: Source code implemented in R is available in the supplementary material under the function r-AMMI.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Research Community on Data-to-Decision (D2D), Centro de Matemática e Aplicações (CMA, NOVA University of Lisbon
Contributors: Rodrigues, P. C., Monteiro, A., Lourenço, V. M.
Number of pages: 9
Pages: 58-66
Publication date: 1 Jul 2015
Peer-reviewed: Yes

Publication information

Journal: Bioinformatics
Volume: 32
Issue number: 1
ISSN (Print): 1367-4803
Ratings: 
  • Scopus rating (2015): CiteScore 6.06 SJR 4.97 SNIP 2.16
Original language: English
ASJC Scopus subject areas: Biochemistry, Molecular Biology, Computational Theory and Mathematics, Computer Science Applications, Computational Mathematics, Statistics and Probability, Medicine(all)
Source: Scopus
Source ID: 84959872026

Research output: Contribution to journalArticleScientificpeer-review

Planar monopole antennas on substrates fabricated through an additive manufacturing process

This paper introduces a new method for creating a flexible antenna using additive manufacturing for the construction of the substrate. Two substrates were created using a 3D multi-material polymer printer. These substrates were composed using different ratios of the two materials supported by the printer. Planar monopole antennas with a bevel were placed on top of these substrates to form flexible antennas. This paper demonstrates a quick way to create antennas that can be used on non-rigid structures.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Sensing Systems for Wireless Medicine (MediSense), Georgia Institute of Technology, School of Electrical and Computer Engineering, George Woodruff School of Mechanical Engineering, Georgia Institute of Technology
Contributors: Saintsing, C. D., Yu, K., Qi, H. J., Tentzeris, M.
Number of pages: 3
Pages: 159-161
Publication date: 19 Jun 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Radio and Wireless Symposium, RWS
Volume: 2015-June
Issue number: June
Article number: 7129744
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Computer Science Applications, Electrical and Electronic Engineering, Communication
Keywords: 3D Printing, Additive Manufacturing, Broadband Antennas, Flexible Antennas
Source: Scopus
Source ID: 84937963448

Research output: Contribution to journalArticleScientificpeer-review

Long-term epileptic EEG classification via 2D mapping and textural features

Interpretation of long-term Electroencephalography (EEG) records is a tiresome task for clinicians. This paper presents an efficient, low cost and novel approach for patient-specific classification of long-term epileptic EEG records. We aim to achieve this with the minimum supervision from the neurologist. To accomplish this objective, first a novel feature extraction method is proposed based on the mapping of EEG signals into two dimensional space, resulting into a texture image. The texture image is constructed by mapping and scaling EEG signals and their associated frequency sub-bands into the gray-level image domain. Image texture analysis using gray level co-occurrence matrix (GLCM) is then applied in order to extract multivariate features which are able to differentiate between seizure and seizure-free events. To evaluate the discriminative power of the proposed feature extraction method, a comparative study is performed, against other dedicated feature extraction methods. The comparative performance evaluations show that the proposed feature extraction method can outperform other state-of-art feature extraction methods with a low computational cost. With a training rate of 25%, the overall sensitivity of 70.19% and specificity of 97.74% are achieved in the classification of over 163 h of EEG records using support vector machine (SVM) classifiers with linear kernels and trained by the stochastic gradient descent (SGD) algorithm.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Video, Research group: Filterbanks, Research Community on Data-to-Decision (D2D), Qatar University
Contributors: Samiee, K., Kiranyaz, S., Gabbouj, M., Saramäki, T.
Number of pages: 11
Pages: 7175-7185
Publication date: 8 Jun 2015
Peer-reviewed: Yes

Publication information

Journal: Expert Systems with Applications
Volume: 42
Issue number: 20
ISSN (Print): 0957-4174
Ratings: 
  • Scopus rating (2015): CiteScore 4.11 SJR 1.473 SNIP 2.509
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Computer Science Applications, Engineering(all)
Keywords: CHB-MIT dataset, Electroencephalography, Epileptic seizure classification, Haralick, Stochastic gradient descent, Textural features
Source: Scopus
Source ID: 84930636361

Research output: Contribution to journalArticleScientificpeer-review

Urothelial cancer gene regulatory networks inferred from large-scale RNAseq, Bead and Oligo gene expression data

Background: Urothelial pathogenesis is a complex process driven by an underlying network of interconnected genes. The identification of novel genomic target regions and gene targets that drive urothelial carcinogenesis is crucial in order to improve our current limited understanding of urothelial cancer (UC) on the molecular level. The inference of genome-wide gene regulatory networks (GRN) from large-scale gene expression data provides a promising approach for a detailed investigation of the underlying network structure associated to urothelial carcinogenesis. Methods: In our study we inferred and compared three GRNs by the application of the BC3Net inference algorithm to large-scale transitional cell carcinoma gene expression data sets from Illumina RNAseq (179 samples), Illumina Bead arrays (165 samples) and Affymetrix Oligo microarrays (188 samples). We investigated the structural and functional properties of GRNs for the identification of molecular targets associated to urothelial cancer. Results: We found that the urothelial cancer (UC) GRNs show a significant enrichment of subnetworks that are associated with known cancer hallmarks including cell cycle, immune response, signaling, differentiation and translation. Interestingly, the most prominent subnetworks of co-located genes were found on chromosome regions 5q31.3 (RNAseq), 8q24.3 (Oligo) and 1q23.3 (Bead), which all represent known genomic regions frequently deregulated or aberated in urothelial cancer and other cancer types. Furthermore, the identified hub genes of the individual GRNs, e.g., HID1/DMC1 (tumor development), RNF17/TDRD4 (cancer antigen) and CYP4A11 (angiogenesis/ metastasis) are known cancer associated markers. The GRNs were highly dataset specific on the interaction level between individual genes, but showed large similarities on the biological function level represented by subnetworks. Remarkably, the RNAseq UC GRN showed twice the proportion of significant functional subnetworks. Based on our analysis of inferential and experimental networks the Bead UC GRN showed the lowest performance compared to the RNAseq and Oligo UC GRNs. Conclusion: To our knowledge, this is the first study investigating genome-scale UC GRNs. RNAseq based gene expression data is the data platform of choice for a GRN inference. Our study offers new avenues for the identification of novel putative diagnostic targets for subsequent studies in bladder tumors.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, BioMediTech, Research Community on Data-to-Decision (D2D), BioMediTech - Institute of Biosciences and Medical Technology, Queen's University, Belfast, Northern Ireland
Contributors: Matos Simoes, R. D., Dalleau, S., Williamson, K. E., Emmert-Streib, F.
Publication date: 14 May 2015
Peer-reviewed: Yes

Publication information

Journal: BMC Systems Biology
Volume: 9
Article number: 21
ISSN (Print): 1752-0509
Ratings: 
  • Scopus rating (2015): CiteScore 2.54 SJR 1.549 SNIP 0.89
Original language: English
ASJC Scopus subject areas: Molecular Biology, Structural Biology, Applied Mathematics, Modelling and Simulation, Computer Science Applications
Keywords: BC3Net, Computational genomics, Gene regulatory network, Urothelial cancer
Source: Scopus
Source ID: 84931068065

Research output: Contribution to journalArticleScientificpeer-review

Recent advances in antenna design and interference cancellation algorithms for in-band full duplex relays

In-band full-duplex relays transmit and receive simultaneously at the same center frequency, hence offering enhanced spectral efficiency for relay deployment. In order to deploy such full-duplex relays, it is necessary to efficiently mitigate the inherent self-interference stemming from the strong transmit signal coupling to the sensitive receive chain. In this article, we present novel state-of-the-art antenna solutions as well as digital self-interference cancellation algorithms for compact MIMO fullduplex relays, specifically targeted for reduced-cost deployments in local area networks. The presented antenna design builds on resonant wavetraps and is shown to provide passive isolations on the order of 60-70 dB. We also discuss and present advanced digital cancellation solutions, beyond classical linear processing, specifically tailored against nonlinear distortion of the power amplifier when operating close to saturation. Measured results from a complete demonstrator system, integrating antennas, RF cancellation, and nonlinear digital cancellation, are also presented, evidencing close to 100 dB of overall self-interference suppression. The reported results indicate that building and deploying compact full-duplex MIMO relays is already technologically feasible.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Tampere University of Technology, Wireless Communications and Positioning (WICO), Aalto University
Contributors: Heino, M., Korpi, D., Huusari, T., Antonio-Rodríguez, E., Venkatasubramanian, S., Riihonen, T., Anttila, L., Icheln, C., Haneda, K., Wichman, R., Valkama, M.
Number of pages: 11
Pages: 91-101
Publication date: 1 May 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 53
Issue number: 5
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2015): CiteScore 8.15 SJR 2.225 SNIP 5.246
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computer Networks and Communications

Bibliographical note

AUX=elt,"Huusari, Timo"

Source: Scopus
Source ID: 84929335830

Research output: Contribution to journalArticleScientificpeer-review

Multistep reactions of water with small Pdn clusters: A first principles study

Multistep dissociative chemisorption reactions of water with Pd4 and Pd7 clusters were studied using density functional theory. The adsorption energies and referred adsorption sites from water molecule (H2O) to partially dissociative (H2+O and OH+H), then to fully dissociative (O+H+H) configurations are carefully determined. It is found that the adsorption energies of three dissociative reactions are 5-6 times larger than that of water molecule. Atop sites of Pd4 and Pd7 clusters are found to be the most stable sites for the adsorbed H2O molecule. For the coadsorption cases of partially and fully dissociated products, H2 and OH molecules preferably tend to bind at the low coordination (atop or bridge) sites, and O and H atoms prefer to adsorb on the high coordination (hollow) sites. It is also found that the most favorable adsorption sites for the molecular adsorbates (H2O, H2 and OH) are adjacent to the Pd atoms with the largest site-specific polarizabilities. Therefore, site-specific polarizability is a good predictor of the favorable adsorption sites for the weakly bound molecules. The different directions of charge transfer between the Pd clusters and the adsorbate(s) is observed. Furthermore, the processes of the adsorption, dissociation, and the dissociative products diffusion of H2O are analyzed.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Computational Science X (CompX), Northwest University China, Nanjing University
Contributors: Liang, Y., Ma, L., Wang, J., Wang, G.
Publication date: 1 May 2015
Peer-reviewed: Yes

Publication information

Journal: Journal of Theoretical and Computational Chemistry
Volume: 14
Issue number: 3
Article number: 1550017
ISSN (Print): 0219-6336
Ratings: 
  • Scopus rating (2015): CiteScore 0.57 SJR 0.249 SNIP 0.321
Original language: English
ASJC Scopus subject areas: Physical and Theoretical Chemistry, Computational Theory and Mathematics, Computer Science Applications
Keywords: Chemisorption, cluster, density functional theory, transition state

Research output: Contribution to journalArticleScientificpeer-review

The internet of Bio-Nano things

The Internet of Things (IoT) has become an important research topic in the last decade, where things refer to interconnected machines and objects with embedded computing capabilities employed to extend the Internet to many application domains. While research and development continue for general IoT devices, there are many application domains where very tiny, concealable, and non-intrusive Things are needed. The properties of recently studied nanomaterials, such as graphene, have inspired the concept of Internet of NanoThings (IoNT), based on the interconnection of nanoscale devices. Despite being an enabler for many applications, the artificial nature of IoNT devices can be detrimental where the deployment of NanoThings could result in unwanted effects on health or pollution. The novel paradigm of the Internet of Bio-Nano Things (IoBNT) is introduced in this paper by stemming from synthetic biology and nanotechnology tools that allow the engineering of biological embedded computing devices. Based on biological cells, and their functionalities in the biochemical domain, Bio-NanoThings promise to enable applications such as intra-body sensing and actuation networks, and environmental control of toxic agents and pollution. The IoBNT stands as a paradigm-shifting concept for communication and network engineering, where novel challenges are faced to develop efficient and safe techniques for the exchange of information, interaction, and networking within the biochemical domain, while enabling an interface to the electrical domain of the Internet.

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 Nebraska, Georgia Institute of Technology
Contributors: Akyildiz, I. F., Pierobon, M., Balasubramaniam, S., Koucheryavy, Y.
Number of pages: 9
Pages: 32-40
Publication date: 1 Mar 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 53
Issue number: 3
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2015): CiteScore 8.15 SJR 2.225 SNIP 5.246
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computer Networks and Communications
Source: Scopus
Source ID: 84925851587

Research output: Contribution to journalArticleScientificpeer-review

Designing controllers with reduced order internal models

In this technical note we study robust output tracking for autonomous linear systems. We introduce a new approach to designing robust controllers using a recent observation that a full internal model is not always necessary for robustness. Especially this may be the case if the control law is only required to be robust with respect to a specific predetermined class of uncertainties in the parameters of the plant. The results are illustrated with an example on robust output tracking for coupled harmonic oscillators.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Mathematics, Research group: MAT Mathematical and semantic modelling
Contributors: Paunonen, L.
Number of pages: 6
Pages: 775-780
Publication date: 1 Mar 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Transactions on Automatic Control
Volume: 60
Issue number: 3
Article number: 6826480
ISSN (Print): 0018-9286
Ratings: 
  • Scopus rating (2015): CiteScore 5.08 SJR 4.285 SNIP 3.213
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Control and Systems Engineering, Computer Science Applications
Source: Scopus
Source ID: 84923355671

Research output: Contribution to journalArticleScientificpeer-review

Task-based information interaction evaluation: The viewpoint of program theory

Evaluation is central in research and development of information retrieval (IR). In addition to designing and implementing new retrieval mechanisms, one must also show through rigorous evaluation that they are effective. A major focus in IR is IR mechanisms' capability of ranking relevant documents optimally for the users, given a query. Searching for information in practice involves searchers, however, and is highly interactive. When human searchers have been incorporated in evaluation studies, the results have of ten suggested that better ranking does not necessarily lead to better search task, or work task, performance. Therefore, it is not clear which system or interface features should be developed to improve the effectiveness of human task performance. In the present article, we focus on the evaluation of task-based information interaction (TBII). We give special emphasis to learning tasks to discuss TBII in more concrete terms. Information interaction is here understood as behavioral and cognitive activities related to task planning, searching information items, selecting between them, working with them, and synthesizing and reporting. These five generic activities contribute to task performance and outcome and can be supported by information systems. In an attempt toward task-based evaluation, we introduce program theory as the evaluation framework. Such evaluation can investigate whether a program consisting of TBII activities and tools works and how it works and, further, provides a causal description of program (in)effectiveness. Our goal in the present article is to structure TBII on the basis of the five generic activities and consider the evaluation of each activity using the program theory framework. Finally, we combine these activity-based program theories in an overall evaluation framework for TBII. Such an evaluation is complex due to the large number of factors affecting information interaction. Instead of presenting tested program theories, we illustrate how the evaluation of TBII should be accomplished using the program theory framework in the evaluation of systems and behaviors, and their interactions, comprehensively in context.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: University of Tampere
Contributors: Järvelin, K., Vakkari, P., Arvola, P., Baskaya, F., Järvelin, A., Kekäläinen, J., Keskustalo, H., Kumpulainen, S., Saastamoinen, M., Savolainen, R., Sormunen, E.
Publication date: 1 Mar 2015
Peer-reviewed: Yes

Publication information

Journal: ACM Transactions on Information Systems
Volume: 33
Issue number: 1
Article number: 3
ISSN (Print): 1046-8188
Ratings: 
  • Scopus rating (2015): CiteScore 2.71 SJR 0.655 SNIP 2.007
Original language: English
ASJC Scopus subject areas: Information Systems, Business, Management and Accounting(all), Computer Science Applications
Keywords: Experimentation, Human factors, Theory
Source: Scopus
Source ID: 84926320780

Research output: Contribution to journalArticleScientificpeer-review

Communication challenges in high-density deployments of wearable wireless devices

Wearable wireless devices are very likely to soon move into the mainstream of our society, led by the rapidly expanding multibillion dollar health and fitness markets. Should wearable technology sales follow the same pattern as those of smartphones and tablets, these new devices (a.k.a. wearables) will see explosive growth and high adoption rates over the next five years. It also means that wearables will need to become more sophisticated, capturing what the user sees, hears, or even feels. However, with an avalanche of new wearables, we will need to find ways to supply them with low-latency highspeed data connections to enable truly demanding use cases such as augmented reality. This is particularly true for high-density wearable computing scenarios, such as public transportation, where existing wireless technology may have difficulty supporting stringent application requirements. In this article, we summarize our recent progress in this area with a comprehensive review of current and emerging connectivity solutions for high-density wearable deployments, their relative performance, and open communication challenges.

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, Intelligent dexterity for secure networked infrastructure and applications (IDSNIA), Intel Corporation
Contributors: Pyattaev, A., Johnsson, K., Andreev, S., Koucheryavy, Y.
Number of pages: 7
Pages: 12-18
Publication date: 1 Feb 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Wireless Communications
Volume: 22
Issue number: 1
ISSN (Print): 1536-1284
Ratings: 
  • Scopus rating (2015): CiteScore 6.69 SJR 1.913 SNIP 3.885
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications
Source: Scopus
Source ID: 84924943737

Research output: Contribution to journalArticleScientificpeer-review

Fault tolerant control architecture design for mobile manipulation in scientific facilities

This paper describes one of the challenging issues implied by scientific infrastructures on a mobile robot cognition architecture. For a generally applicable cognition architecture, we study the dependencies and logical relations between several tasks and subsystems. The overall view of the software modules is described, including their relationship with a fault management module that monitors the consistency of the data flow among the modules. The fault management module is the solution of the deliberative architecture for the single point failures, and the safety anchor is the reactive solution for the faults by redundant equipment. In addition, a hardware architecture is proposed to ensure safe robot movement as a redundancy for the cognition of the robot. The method is designed for a four-wheel steerable (4WS) mobile manipulator (iMoro) as a case study.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Intelligent Hydraulics and Automation, Research group: Mobile manipulation, Research group: Field robotics and control, Field robotics for efficient work sites (FIRE)
Contributors: M. Aref, M., Oftadeh, R., Ghabcheloo, R., Mattila, J.
Publication date: 29 Jan 2015
Peer-reviewed: Yes

Publication information

Journal: international Journal of Advanced Robotic Systems
Volume: 12
Issue number: 4
ISSN (Print): 1729-8806
Ratings: 
  • Scopus rating (2015): CiteScore 1.02 SJR 0.346 SNIP 0.932
Original language: English
ASJC Scopus subject areas: Software, Artificial Intelligence, Computer Science Applications
Keywords: Architecture design, Autonomous vehicle drive, Cognition, Mobile robot, Remote handling
Source: Scopus
Source ID: 84923377541

Research output: Contribution to journalArticleScientificpeer-review

Estimation of GFP-tagged RNA numbers from temporal fluorescence intensity data

Motivation: MS2-GFP-tagging of RNA is currently the only method to measure intervals between consecutive transcription events in live cells. For this, new transcripts must be accurately detected from intensity time traces. Results: We present a novel method for automatically estimating RNA numbers and production intervals from temporal data of cell fluorescence intensities that reduces uncertainty by exploiting temporal information. We also derive a robust variant, more resistant to outliers caused e.g. by RNAs moving out of focus. Using Monte Carlo simulations, we show that the quantification of RNA numbers and production intervals is generally improved compared with previous methods. Finally, we analyze data from live Escherichia coli and show statistically significant differences to previous methods. The new methods can be used to quantify numbers and production intervals of any fluorescent probes, which are present in low copy numbers, are brighter than the cell background and degrade slowly. Availability: Source code is available under Mozilla Public License at http://www.cs.tut.fi/%7ehakkin22/jumpdet/. Contact:

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Laboratory of Biosystem Dynamics-LBD, Multi-scaled biodata analysis and modelling (MultiBAM)
Contributors: Häkkinen, A., Ribeiro, A. S.
Number of pages: 7
Pages: 69-75
Publication date: 1 Jan 2015
Peer-reviewed: Yes

Publication information

Journal: Bioinformatics
Volume: 31
Issue number: 1
ISSN (Print): 1367-4803
Ratings: 
  • Scopus rating (2015): CiteScore 6.06 SJR 4.97 SNIP 2.16
Original language: English
ASJC Scopus subject areas: Biochemistry, Molecular Biology, Computational Theory and Mathematics, Computer Science Applications, Computational Mathematics, Statistics and Probability, Medicine(all)

Bibliographical note

Contribution: organisation=sgn,FACT1=1<br/>Portfolio EDEND: 2014-09-15<br/>Publisher name: Oxford University Press

Source: researchoutputwizard
Source ID: 396

Research output: Contribution to journalArticleScientificpeer-review

Spectral and energy efficiency of ultra-dense networks under different deployment strategies

To tackle the 1000× mobile data challenge, the research towards the 5th generation of mobile cellular networks is currently ongoing. One clear enabler toward substantially improved network area capacities is the increasing level of network densification at different layers of the overall heterogeneous radio access system. Ultra-dense deployments, or DenseNets, seek to take network densification to a whole new level, where extreme spatial reuse is deployed. This article looks into DenseNets from the perspectives of different deployment strategies, covering the densification of the classical macro layer, extremely dense indoor femto layer, as well as outdoor distributed antenna system (DAS), which can be dynamically configured as a single microcell or multiple independent microcells. Also, the potential of a new indoor-to-outdoor service provisioning paradigm is examined. The different deployment solutions are analyzed from the network area spectral and network energy efficiency perspectives, with extreme densification levels, including both indoor and outdoor use scenarios. The obtained results indicate that dedicated indoor solutions with densely deployed femtocells are much more spectrumand energy-efficient approaches to address the enormous indoor capacity demands compared to densifying the outdoor macro layer, when the systems are pushed to their capacity limits. Furthermore, the dynamic outdoor DAS concept offers an efficient and capacity-adaptive solution to provide outdoor capacity, on demand, in urban areas.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Electronics and Communications Engineering, Research group: Wireless Communications and Positioning, Wireless Communications and Positioning (WICO)
Contributors: Yunas, S., Valkama, M., Niemelä, J.
Number of pages: 11
Pages: 90-100
Publication date: 1 Jan 2015
Peer-reviewed: Yes

Publication information

Journal: IEEE Communications Magazine
Volume: 53
Issue number: 1
ISSN (Print): 0163-6804
Ratings: 
  • Scopus rating (2015): CiteScore 8.15 SJR 2.225 SNIP 5.246
Original language: English
ASJC Scopus subject areas: Electrical and Electronic Engineering, Computer Science Applications, Computer Networks and Communications
Source: Scopus
Source ID: 84921459532

Research output: Contribution to journalArticleScientificpeer-review

The assessment of constructability: BIM cases

The constructability appraisal methods developed so far are based on evaluating and analysing the major design components and systems of an entire building, such as structural systems, materials and production techniques. At first, this paper discusses the current practice of constructability assessment used in Finland and next it introduces an experimental constructability assessment method (ECAM) using building information models (BIM) as a source of constructability information. Interviews of design and construction professionals were used to explore the current practice of constructability assessment. An experimental assessment methodology was developed and tested in case projects. According to the interviews, the main assessment method used was the inspection of drawings, and constructability was assessed occasionally during the design development stage and more systematically at the very end of the detailed design stage with varying professional participants in meetings. Using ECAM in the project level a constructability score of a building and building type can be analysed. When using ECAM on the level of structural elements a constructability score of elements can be measured. These scores incorporate information for the development of constructability. In Finland, the development of a systematic review process of constructability will be needed. The constructability assessment methodology suggested in the article is experimental and is to be developed and tested further before using it reliably in building projects. The assessment combining visual and analytical approach will change present methods for assessing constructability.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Life Cycle Effectiveness of the Built Environment (LCE@BE), Aalto University
Contributors: Tauriainen, M. K., Puttonen, J. A., Saari, A. J.
Number of pages: 17
Pages: 51-67
Publication date: 1 Jan 2015
Peer-reviewed: Yes

Publication information

Journal: Journal of Information Technology in Construction
Volume: 20
ISSN (Print): 1403-6835
Ratings: 
  • Scopus rating (2015): CiteScore 1.18 SJR 0.398 SNIP 1.129
Original language: English
ASJC Scopus subject areas: Civil and Structural Engineering, Building and Construction, Computer Science Applications
Keywords: Analyses, Assessment, BIM, Buildability, Constructability, Modelling, Quantitative
Source: Scopus
Source ID: 84921652278

Research output: Contribution to journalArticleScientificpeer-review

Distant speech separation using predicted time-frequency masks from spatial features

Speech separation algorithms are faced with a difficult task of producing high degree of separation without containing unwanted artifacts. The time-frequency (T-F) masking technique applies a real-valued (or binary) mask on top of the signal's spectrum to filter out unwanted components. The practical difficulty lies in the mask estimation. Often, using efficient masks engineered for separation performance leads to presence of unwanted musical noise artifacts in the separated signal. This lowers the perceptual quality and intelligibility of the output. Microphone arrays have been long studied for processing of distant speech. This work uses a feed-forward neural network for mapping microphone array's spatial features into a T-F mask. Wiener filter is used as a desired mask for training the neural network using speech examples in simulated setting. The T-F masks predicted by the neural network are combined to obtain an enhanced separation mask that exploits the information regarding interference between all sources. The final mask is applied to the delay-and-sum beamformer (DSB) output. The algorithm's objective separation capability in conjunction with the separated speech intelligibility is tested with recorded speech from distant talkers in two rooms from two distances. The results show improvement in instrumental measure for intelligibility and frequency-weighted SNR over complex-valued non-negative matrix factorization (CNMF) source separation approach, spatial sound source separation, and conventional beamforming methods such as the DSB and minimum variance distortionless response (MVDR).

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research group: Audio research group
Contributors: Pertilä, P., Nikunen, J.
Number of pages: 10
Pages: 97-106
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: Speech Communication
Volume: 68
ISSN (Print): 0167-6393
Ratings: 
  • Scopus rating (2015): CiteScore 2.21 SJR 0.49 SNIP 1.612
Original language: English
ASJC Scopus subject areas: Modelling and Simulation, Computer Science Applications, Computer Vision and Pattern Recognition, Software, Communication, Linguistics and Language, Language and Linguistics
Keywords: Beamforming, Microphone arrays, Neural networks, Speech separation, Time-frequency masking
Source: Scopus
Source ID: 84923277715

Research output: Contribution to journalArticleScientificpeer-review

Extreme learning machine based supervised subspace learning

This paper proposes a novel method for supervised subspace learning based on Single-hidden Layer Feedforward Neural networks. The proposed method calculates appropriate network target vectors by formulating a Bayesian model exploiting 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 hidden layer outputs. After the calculation of the network target vectors, Extreme Learning Machine-based neural network training is applied and classification is performed using a Nearest Neighbor classifier. Experimental results on publicly available data sets show that the proposed approach consistently outperforms the standard ELM approach, as well as other standard methods.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Department of Signal Processing, Research Community on Data-to-Decision (D2D)
Contributors: Iosifidis, A.
Number of pages: 7
Pages: 158–164
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: Neurocomputing
Volume: 167
ISSN (Print): 0925-2312
Ratings: 
  • Scopus rating (2015): CiteScore 3.18 SJR 0.981 SNIP 1.698
Original language: English
ASJC Scopus subject areas: Artificial Intelligence, Computer Science Applications, Cognitive Neuroscience
Keywords: Extreme Learning Machine, Network targets calculation, Supervised subspace learning

Research output: Contribution to journalArticleScientificpeer-review

Busting myths of electronic word of mouth: The relationship between customer ratings and the sales of mobile applications

Business and academic research frequently highlights the power of electronic word of mouth, relying on the knowledge that online customer ratings and reviews influence consumer decision making. Numerous studies in different disciplines have been conducted to examine the effectiveness of electronic word of mouth communication. Previously, typically small sample studies suggest that positive electronic word of mouth increases sales and that the effects depend on the volume and valence of reviews and ratings. This study’s contribution lies in testing the relationship between electronic word of mouth and the sales of applications in a mobile application ecosystem (Google Play) with an extensive dataset (over 260 million customer ratings; 18 months). The results show that higher values of valence of customer ratings correlate statistically significantly with higher sales. The volume of ratings correlates positively with sales in the long term but negatively in the short term. Furthermore, the relationship between electronic word of mouth and sales seems to be more important when the price of the application increases. The findings also underline the importance of the choice of a measurement period in studies.

General information

Publication status: Published
MoE publication type: A1 Journal article-refereed
Organisations: Managing digital industrial transformation (mDIT), Pori Department, Research group: Business Ecosystems, Networks and Innovations, Turun Yliopisto/Turun Biomateriaalikeskus, University of Turku, Turku School of Economics, VTT Technical Research Centre of Finland, University of Turku
Contributors: Hyrynsalmi, S., Seppänen, M., Aarikka-Stenroos, L., Suominen, A., Järveläinen, J., Harkke, V.
Number of pages: 18
Pages: 1-18
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: Journal of Theoretical and Applied Electronic Commerce Research
Volume: 10
Issue number: 2
ISSN (Print): 0718-1876
Ratings: 
  • Scopus rating (2015): CiteScore 1.84 SJR 0.749 SNIP 1.394
Original language: English
ASJC Scopus subject areas: Business, Management and Accounting(all), Computer Science Applications
Keywords: App stores, Big data, Consumer ratings, Consumer reviews, Electronic word of mouth, Micro-pricing, Products ratings, Sales

Bibliographical note

EXT="Aarikka-Stenroos, Leena"
EXT="Hyrynsalmi, Sami"

Versio ja lupa ok 12.1.2016, lupa annettu lomakkeella KK

Source: Scopus
Source ID: 84930678533

Research output: Contribution to journalArticleScientificpeer-review

Smart home gateway system over Bluetooth low energy with wireless energy transfer capability

As billions of sensors and smart meters connect to the Internet of Things (IoT), current wireless technologies are taking decisive steps to ensure their sustainable operation. One popular IoT scenario features a smart home service gateway, which becomes the central point of user’s home environment facilitating a multitude of tasks. Given that most IoT devices connected to residential gateway are small-scale and battery-powered, the key challenge is to extend their lifetime without recharging/replacing batteries. To this end, a novel radio technology named Bluetooth low energy (BLE) has recently been completed to enable energy-efficient data transfer. Another inspiring innovation is the capability of sensors to harvest wireless energy in their local environment. In this work, we envision a scenario where many in-home sensors are communicating with a smart gateway over the BLE protocol, while at the same time harvesting RF energy transmitted from the gateway wirelessly via a dedicated radio interface. We thoroughly investigate performance limitations of such wireless energy transfer interface (WETI) with dynamic analytical model and with important practical considerations. Our methodology delivers the upper bound on WETI operation coupled with BLE-based communication, which characterizes ultimate system performance over the class of practical radio and energy resource management algorithms.

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), International Insitute for Advanced Aerospace Technologies of St. Petersburg State University of Aerospace Instrumentation
Contributors: Galinina, O., Mikhaylov, K., Andreev, S., Turlikov, A., Koucheryavy, Y.
Publication date: 2015
Peer-reviewed: Yes

Publication information

Journal: Eurasip Journal on Wireless Communications and Networking
Volume: 2015
Issue number: 1
Article number: 178
ISSN (Print): 1687-1472
Ratings: 
  • Scopus rating (2015): CiteScore 0.96 SJR 0.362 SNIP 1.138
Original language: English
ASJC Scopus subject areas: Computer Networks and Communications, Signal Processing, Computer Science Applications
Keywords: Bluetooth low energy, Internet of Things, Sensors, Smart home gateway, Wireless energy transfer
Source: Scopus
Source ID: 84938840129

Research output: Contribution to journalArticleScientificpeer-review

Uncertainty propagation of iron loss from characterization measurements to computation of electrical machines

Purpose - The purpose of this paper is to find out how uncertainties in the characterization of magnetic materials propagate through identification and numerical simulation to the computation of iron losses in electrical machines. Design/methodology/approach - The probabilistic uncertainties in the iron losses are modelled with the spectral approach using chaos polynomials. The Sobol indices are used for the global sensitivity analysis. The machine is modelled with a 2D finite element method and the iron losses are computed with a previously developed accurate method. Findings - The uncertainties propagate in different ways to the different components of losses, i.e. eddy current, hysteresis, and excess losses. The propagation is also different depending on the investigated region of the machine, i.e. Stator or rotor teeth, yokes, tooth tips. Research limitations/implications - The method does not account for uncertainties related to the manufacturing process, which might result in even larger variability. Practical implications - A major implication of the findings is that the identification of iron loss parameters at low frequencies does not affect the loss variability. The identification with high-frequency measurement is very important for the rotor tooth tips. The variability in the excess loss parameters is of low impact. Originality/value - The presented results are of importance for the magnetic material manufacturers and the electrical machine designers. The manufacturers can plan the measurement and identification procedures as to minimize the output variability of the parameters. The designers of the machine can use the result and the presented procedures to estimate the variability of their design.

General information

Publication status: Published
MoE publication type: