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  • 51.
    Grünwald, Norbert
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    A Mixed-Reality Platform for Robotics and Intelligent Vehicles2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Mixed Reality is the combination of the real world with a virtual one. In robotics thisopens many opportunities to improve the existing ways of development and testing. Thetools that Mixed Reality gives us, can speed up the development process and increasesafety during the testing stages. They can make prototyping faster and cheaper, and canboost the development and debugging process thanks to visualization and new opportunitiesfor automated testing.In this thesis the steps to build a working prototype demonstrator of a Mixed Realitysystem are covered. From selecting the required components, over integrating them intofunctional subsystems, to building a fully working demonstration system.The demonstrator uses optical tracking to gather information about the real world environment.It incorporates this data into a virtual representation of the world. This allowsthe simulation to let virtual and physical objects interact with each other. The results ofthe simulation are then visualized back into the real world.The presented system has been implemented and successfully tested at the HalmstadUniversity.

  • 52.
    Hasan, Meqdad
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Kali, Rahul
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Method for Autonomous picking of paper reels2011Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Autonomous forklift handling systems is one of the most interesting research in the last decades. While research fields such as path planning and map building are taking the most significant work for other type of autonomous vehicles, detecting objects that need to move and picking it up becomes one of the most important research fields in autonomous forklifts field.

    We in this research had provided an algorithm for detecting paper reels accurate position in paper reels warehouses giving a map of the warehouse itself. Another algorithm is provided for giving the priority of papers that want to be picked up. Finally two algorithms for choosing the most appropriate direction for picking the target reel and for choosing the safest path to reach the target reel without damage it are provided.

    While working on the last two algorithms shows very nice results, building map for unknown stake of papers by accumulating maps over time still tricky. In the following pages we will go in detail by the steps that we followed to provide these algorithms started from giving an over view to the problem background and moving through the method that we used or we developed and ending by result and the conclusion that we got from this work.

  • 53.
    Kalsyte, Zivile
    et al.
    Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab). Kaunas University of Technology, Kaunas, Lithuania.
    Vasiliauskaite, Asta
    Kaunas University of Technology, Kaunas, Lithuania.
    Predicting trends of financial attributes by an adaptive committee of models2012In: Proceedings of the 7th International Conference on Electrical and Control Technologies ECT 2012 / [ed] A. Navickas (Editor-in-Chief), A. Sauhats, A. Virbalis, M. Ažubalis, V. Galvanauskas, K. Brazauskas & A. Jonaitis, Kaunas: Kaunas University of Technology , 2012, p. 48-53Conference paper (Refereed)
    Abstract [en]

    This paper presents an approach to designing an adaptive, data dependent, committee of multilayer perceptrons (MLP) for predicting trends (positive or negative change) of five financial attributes used for assessing future performance of a company. Total Asset Turnover [TAT], Current Ratio [CR], Gross Margin [GM], Operating Margin [OM], and Return on Equity [ROE] are the attributes used in this paper. A two- and three-years ahead prediction of change is considered. A Self-Organizing Map (SOM) used for data mapping and analysis enables building committees, which are specific (committee size and aggregation parameters) for each data point analyzed. When tested on data concerning 59 companies of the United States biotechnology sector, committees built according to the proposed technique outperformed both averaging and weighted averaging committees.

  • 54.
    Kamińska, Hanna
    et al.
    Institute of Biomedical Engineering and Instrumentation, Wroclaw University of Technology, Wroclaw, Poland.
    Rögnvaldsson, Thorsteinn
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Evaluation of a new probabilistic approach to scoring algorithms in protein identification by Peptide Mass Fingerprinting (PMF)2011In: Nutraceutics, biomedical remedies and physiotherapeutic methods for prevention of civilization-related diseases / [ed] Halina Podbielska, Tadeusz Trziszka, Wroclaw, Poland: Indygo Zahir Media , 2011, p. 171-180Chapter in book (Other academic)
    Abstract [en]

    The protein identification performs a crucial role in the contemporary medicine. Proteins may act as the potential biomarkers for investigating many diseases, e.g. the civilization-related ones.  Peptide mass fingerprinting (PMF) is a widely used protein identification method basing on mass spectrometry data. Economical reasons and time savings are of great importance in the identification experiments. Thereby, innovative ideas, which have the potential to improve the PMF identification, are still desired. A novel probability-based scoring scheme, which constitutes the last part of the PMF identification procedure, was developed. Presented scoring scheme incorporates an innovative idea, which assumes a different approach to modelling the distribution of proteins derived from the database, on the basis of which the score is computed. In the paper we assess a performance of the proposed scoring method against popular scoring scheme, i.e. Mascot (http://www.matrixscience.com/). The comparison of the methods includes scoring results obtained for the simulated data. Different levels of proteins samples contamination and different coverage of peptides sequences were considered in the empirical study.

  • 55.
    Karginova, Nadezda
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Identification of Driving Styles in Buses2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    It is important to detect faults in bus details at an early stage. Because the driving style affects the breakdown of different details in the bus, identification of the driving style is important to minimize the number of failures in buses.

    The identification of the driving style of the driver was based on the input data which contained examples of the driving runs of each class. K-nearest neighbor and neural networks algorithms were used. Different models were tested.

    It was shown that the results depend on the selected driving runs. A hypothesis was suggested that the examples from different driving runs have different parameters which affect the results of the classification.

    The best results were achieved by using a subset of variables chosen with help of the forward feature selection procedure. The percent of correct classifications is about 89-90 % for the k-nearest neighbor algorithm and 88-93 % for the neural networks.

    Feature selection allowed a significant improvement in the results of the k-nearest neighbor algorithm and in the results of the neural networks algorithm received for the case when the training and testing data sets were selected from the different driving runs. On the other hand, feature selection did not affect the results received with the neural networks for the case when the training and testing data sets were selected from the same driving runs.

    Another way to improve the results is to use smoothing. Computing the average class among a number of consequent examples allowed achieving a decrease in the error.

  • 56.
    Karginova, Nadezda
    et al.
    Petrozavodsk University, Petrozavodsk, Russia.
    Byttner, Stefan
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Svensson, Magnus
    Volvo Group Trucks Technology, Göteborg, Sweden.
    Data-driven methods for classification of driving styles in buses2012Conference paper (Refereed)
    Abstract [en]

    Fuel consumption and vehicle breakdown depend upon the driving style of the driver, for example, hard driving style leads to more wear and consequently more failures of vehicle components. Because of this, it is important to identify and classify the driver’s driving style in order to give the driver feedback through a driver assistance system. The driver would then be able to detect and learn to avoid a driving style that is not appropriate. The input data is provided by different sensors installed in the vehicle, where different drivers and driving routes have been measured. The data is subjectively classified into two different driving styles: normal and hard. Hard driving style can be characterized, for example, by rapid acceleration and braking. Since it is not trivial to build a model which is able to distinguish hard driving from normal, a data mining approach has been employed. In the paper, several classifiers are compared (including e.g. neural networks and decision trees) and a discussion is made on the advantages and disadvantages of the different methods. Copyright © 2012 SAE International.

  • 57.
    Kollreider, Klaus
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Fronthaler, Hartwig
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Bigun, Josef
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Non-intrusive liveness detection by face images2009In: Image and Vision Computing, ISSN 0262-8856, E-ISSN 1872-8138, Vol. 27, no 3, p. 233-244Article in journal (Refereed)
    Abstract [en]

    A technique evaluating liveness in face image sequences is presented. To ensure the actual presence of a live face in contrast to a photograph (playback attack), is a significant problem in face authentication to the extent that anti-spoofing measures are highly desirable. The purpose of the proposed system is to assist in a biometric authentication framework, by adding liveness awareness in a non-intrusive manner. Analyzing the trajectories of certain parts of a live face reveals valuable information to discriminate it against a spoofed one. The proposed system uses a lightweight novel optical flow, which is especially applicable in face motion estimation based on the structure tensor and inputs of a few frames. For reliable face part detection, the system utilizes a model-based local Gabor decomposition and SVM experts, where selected points from a retinotopic grid are used to form regional face models. Also the estimated optical flow is exploited to detect a face part. The whole procedure, starting with three images as input and finishing in a liveness score, is executed in near real-time without special purpose hardware. Experimental results on the proposed system are presented on both a public database and spoofing attack simulations.

  • 58.
    Kruusmaa, Maarja
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Global level path planning for mobile robots in dynamic environments2003In: Journal of Intelligent and Robotic Systems, ISSN 0921-0296, E-ISSN 1573-0409, Vol. 38, no 1, p. 55-83Article in journal (Refereed)
    Abstract [en]

    This paper presents a self- adapting approach to global level path planning in dynamic environments. The aim of this work is to minimize risk and delays in possible applications of mobile robots ( e. g., in industrial processes). We introduce a hybrid system that uses case-based reasoning as well as grid-based maps for decision-making. Maps are used to suggest several alternative paths between specific start and goal point. The casebase stores these solutions and remembers their characteristics. Environment representation and casebase design are discussed. To solve the problem of exploration vs. exploitation, a decision-making strategy is proposed that is based on the irreversibility of decisions. Forgetting strategies are discussed and evaluated in the context of case-based maintenance. The adaptability of the system is evaluated in a domain based on real sensor data with simulated occupancy probabilities. Forgetting strategies and decision-making strategies are evaluated in simulated environments. Experiments show that a robot is able to adapt in dynamic environments and can learn to use paths that are less risky to follow.

  • 59.
    Lundström, Jens
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Assessing print quality by machine in offset colour printing2013In: Knowledge-Based Systems, ISSN 0950-7051, E-ISSN 1872-7409, Vol. 37, p. 70-79Article in journal (Refereed)
    Abstract [en]

    Information processing steps in printing industry are highly automated, except the last one print quality assessment, which usually is a manual, tedious, and subjective procedure. This article presents a random forests-based technique for automatic print quality assessment based on objective values of several printquality attributes. Values of the attributes are obtained from soft sensors through data mining and colour image analysis. Experimental investigations have shown good correspondence between print quality evaluations obtained by the technique proposed and the average observer. (C) 2012 Elsevier B.V. All rights reserved.

  • 60.
    Lundström, Jens
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Detecting Halftone Dots for Offset Print Quality Assessment Using Soft Computing2010In: 2010 IEEE International Conference on Fuzzy Systems (FUZZ), Piscataway, NJ: IEEE Press, 2010, p. 1145-1151Conference paper (Refereed)
    Abstract [en]

    Nowadays in printing industry most of information processing steps are highly automated, except the last one–print quality assessment and control. We present a way to assess one important aspect of print quality, namely the distortion of halftone dots printed colour pictures are made of. The problem is formulated as assessing the distortion of circles detected in microscale images of halftone dot areas. In this paper several known circle detection techniques are explored in terms of accuracy and robustness. We also present a new circle detection technique based on the fuzzy Hough transform (FHT) extended with k-means clustering for detecting positions of accumulator peaks and with an optional fine-tuning step implemented through unsupervised learning. Prior knowledge about the approximate positions and radii of the circles is utilized in the algorithm. Compared to FHT the proposed technique is shown to increase the estimation accuracy of the position and size of detected circles. The techniques are investigated using synthetic and natural images.

  • 61.
    Lütkebohle, Ingo
    et al.
    Bielefeld University, Germany.
    Philippsen, Roland
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Pradeep, Vijay
    Willow Garage Inc., Menlo Park, CA, USA.
    Marder-Eppstein, Eitan
    Willow Garage Inc., Menlo Park, CA, USA.
    Wachsmuth, Sven
    Bielefeld University, Germany.
    Generic middleware support for coordinating robot software components: The Task-State-Pattern2011In: Journal of Software Engineering for Robotics, ISSN 2035-3928, Vol. 2, no 1, p. 20-39Article in journal (Refereed)
    Abstract [en]

    Robot software systems are (again) reaching levels of size and complexity that makes them difficult to construct, evolve, and maintain. One current issue is that systems are increasingly built to perform many different tasks in parallel, each of which must be coordinated and monitored to achieve a goal. If all components were to require different interfaces, system complexity would rapidly grow. General interfaces partially exist on the conceptual level, but their implementations are typically strongly linked to particular architectural proposals, thus reducing re-use and comparability. This paper presents an architecture-agnostic design pattern for the coordination-related component interaction. It results in a simple and clean component interface to invoke specific functionality, monitor task progress, and update the goals of running tasks. It provides an abstract coordination interface with high observability for the development of coordination and architecture. It thus provides value to all stakeholders in the design and implementation of robot software systems: component developers, coordination developers, and system architects. We trace the convergence of concepts and approaches from early coordination systems and through various abstraction proposals. Recently, two very similar realizations were developed independently by the authors. This paper presents the underlying insights and practical experience as a generic software engineering method which we named the Task-State-Pattern. We describe the functionality it provides to component developers and detail the technical steps necessary to implement it in a distributed event-based toolkit for specific application domains. We provide empirical evidence for the relevance and utility of our approach by presenting case studies and discussing how the proposed pattern leads to a flexible system structure with reduced integration effort.

  • 62.
    Mikaelyan, Anna
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bigun, Josef
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Ground truth and evaluation for latent fingerprint matching2012In: 2012 IEEE Computer Society Conference on Computer Vision and Pattern Recognition Workshops, CVPRW 2012, Piscataway, NJ: IEEE Computer Society, 2012, p. 83-88Conference paper (Refereed)
    Abstract [en]

    In forensic fingerprint studies annotated databases is important for evaluating the performance of matchers as well as for educating fingerprint experts. We have estab- lished ground truths of minutia level correspondences for the publicly available NIST SD27 data set, whose minutia have been extracted by forensic fingerprint experts. We per- formed verification tests with two publicly available minutia matchers, Bozorth3 and k-plet, yielding Equal Error Rates of 36% and 40% respectively, suggesting that they have sim- ilar (poor) ability to separate a client from an impostor in latent versus tenprint queries. However, in an identifica- tion scenario, we found performance advantage of k-plet over Bozorth3, suggesting that the former can rank the sim- ilarities of fingerprints better. Regardless of the matcher, the general poor performance is a confirmation of previous findings related to latent vs tenprint matching. A finding influencing future practice is that the minutia level match- ing errors in terms of FA and FR may not be balanced (not equally good) even if FA and FR have been chosen to be so at finger level.

  • 63.
    Minelga, Jonas
    et al.
    Kaunas University of Technology, Kaunas, Lithuania.
    Gelzinis, Adas
    Kaunas University of Technology, Kaunas, Lithuania.
    Vaiciukynas, Evaldas
    Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab). Kaunas University of Technology, Kaunas, Lithuania.
    Bacauskiene, Marija
    Kaunas University of Technology, Kaunas, Lithuania.
    Padervinskis, Evaldas
    Department of Otolaryngology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Uloza, Virgilijus
    Department of Otolaryngology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Comparing Throat and Acoustic Microphones for Laryngeal Pathology Detection from Human Voice2014In: Electrical and Control Technologies: Proceedings of the 9th International Conference on Electrical and Control Technologies ECT-2014 / [ed] A. Navickas (general editor), A. Sauhats, A. Virbalis, M. Ažubalis, V. Galvanauskas, K. Brazauskas & A. Jonaitis, Kaunas: Kaunas University of Technology , 2014, p. 50-53Conference paper (Refereed)
    Abstract [en]

    The aim of this study was to compare acoustic and throat microphones in the voice pathology detection task. Recordings of sustained phonation /a/ were used in the study. Each recording was characterized by a rather large set of diverse features, 1051 features in total. Classification into two classes, namely normal and pathological, was performed using random forest committees. Models trained using data obtained from the throat microphone provided lower classification accuracy. This is probably due to a narrower frequency range of the throat microphone leading to loss of important information. © Kaunas University of Technology, 2014.

  • 64.
    Mozaffari, Alireza
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE). Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS). Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Varaiya, Kunal
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE). Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS). Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Estimation of fiber size distribution in 3D X-ray µCT image datasets2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    The project is a thesis work in master program of Intelligent Systems that’s done by Alireza Mozaffari and Kunal Varaiya with supervising of Dr Kenneth Nilsson and Dr Cristofer Englund.

    In this project we are estimating the depth distribution of different sizes of fibers in a press felt sample. Press felt is a product that is being used in paper industry. In order to evaluate the production process when press felts are made, it is necessary to be able to estimate the fiber sizes in product.

    For this goal, we developed a program in Matlab to process X-ray images of a press felt, scanned by micro-CT scanner that is able to find the fibers of two different known sizes of fibers and estimates the depth distribution of the different fibers.

  • 65.
    Mühlfellner, Peter
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Selection, Analysis and Implementationof Image-based Feature Extraction Approaches for a Heterogenous, Modular and FPGA-based Architecture for Camera-based Driver Assistance Systems2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    We propose a scalable and fexible hardware architecture for the extraction of image features, used in conjunction with an attentional cascade classifier for appearance-based object detection. Individual feature processors calculate feature-values in parallel, using parameter-sets and image data that is distributed via BRAM buffers. This approach can provide high utilization- and throughput-rates for a cascade classifier. Unlike previous hardware implementations, we are able to flexibly assign feature processors to either work on a single- or multiple image windows in parallel, depending on the complexity of the current cascade stage.

    The core of the architecture was implemented in the form of a streaming based FPGA design, and validated in simulation, synthesis, as well as via the use of a Logic Analyser for the verification of the on-chip functionality. For the given implementation, we focused on the design of Haar-like feature processors, but feature processors for a variety of heterogenous feature types, such as Gabor-like features, can also be accomodated by the proposed hardware architecture.

  • 66.
    Mühlfellner, Peter
    et al.
    Volkswagen AG, Group Research, Germany .
    Furgale, Paul Timothy
    Autonomous Systems Lab, ETH Zürich, Switzerland.
    Derendarz, Wojciech
    Volkswagen AG, Group Research, Germany .
    Philippsen, Roland
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Evaluation of Fisheye-Camera Based Visual Multi-Session Localization in a Real-World Scenario2013In: Intelligent Vehicles Symposium (IV), 2013 IEEE Workshop on Environment Perception and Navigation for Intelligent Vehicles, Piscataway, NJ: IEEE Operations Center , 2013, p. 57-62Conference paper (Refereed)
    Abstract [en]

    The European V-Charge project seeks to develop fully automated valet parking and charging of electric vehicles using only low-cost sensors. One of the challenges is to implement robust visual localization using only cameras and stock vehicle sensors. We integrated four monocular, wide-angle, fisheye cameras on a consumer car and implemented a mapping and localization pipeline. Visual features and odometry are combined to build and localize against a keyframe-based three dimensional map. We report results for the first stage of the project, based on two months worth of data acquired under varying conditions, with the objective of localizing against a map created offline. © 2013 IEEE.

  • 67.
    Nilsson, Carl Magnus
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Carlsson, Jörgen
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Malmqvist, Lennart
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Persson, Willy
    Semtech Metallurgy AB, Lund, Sweden.
    Application of optical spectroscopy to paper production1999In: Optical measurement systems for industrial inspection / [ed] Malgorzata Kujawinska, Bellingham, Washington: SPIE - International Society for Optical Engineering, 1999, p. 318-325Conference paper (Refereed)
    Abstract [en]

    Fluorescence from paper following excitation by either ultraviolet or visible light gives information on the chemical composition of the paper. This can be used for on-line monitoring of the paper during production. Such measurements can be performed non-intrusively at sampling rates high enough to give a sub-millimetre resolution at paper webs moving at velocities higher than 20 metres per second. Two types of fluorescence meters, operating at different wavelengths, have been constructed. Together with an optical speedometer they have been tested at newsprint producing paper mills. A fluorescence based method for scanning cross-directional newsprint profiles in the laboratory has been developed. From these measurements the relative shrinkage of the paper during drying can be calculated using time-frequency analysis.

  • 68.
    Petersson, Daniel
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Johansson, Jonas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Holmberg, Ulf
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Åstrand, Björn
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Torque Sensor Free Power Assisted Wheelchair2007In: ICORR '07: 2007 IEEE 10th International Conference on Rehabilitation Robotics : June 12-15, Noordwijk, The Netherlands, Piscataway, N.J.: IEEE Press, 2007, p. 151-157Conference paper (Refereed)
    Abstract [en]

    A power assisted wheelchair combines human power, which is delivered by the arms through the pushrims, with electrical motors, which are powered by a battery. Todays electric power assisted wheelchairs use force sensors to measure the torque exerted on the pushrims by the user. This leads to rather expensive and clumsy constructions. A new design, which only relies on velocity feedback, thus avoiding the use of expensive force sensors in the pushrims, is proposed in this paper. The control design is based on a simple PD-structure with only two design parameters easily tuned to fit a certain user; one parameter is used to adjust the amplification of the user’s force and the other one is used to change the lasting time of the propulsion influence. Since the new assisting control system only relies on the velocity, the torque sensor free power assisted wheelchair will besides giving the user assisting power also give an assistant, which pushes the wheelchair, additional power. This is a big advantage compared to the pushrim activated one, where this benefit for the assistant is not possible.

  • 69.
    Prytz, Rune
    et al.
    Volvo Technology, Göteborg, Sweden.
    Nowaczyk, Sławomir
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Byttner, Stefan
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), CAISR - Center for Applied Intelligent Systems Research.
    Towards relation discovery for diagnostics2011In: Proceedings of the First International Workshop on Data Mining for Service and Maintenance, New York, NY: Association for Computing Machinery (ACM), 2011, p. 23-27Conference paper (Refereed)
    Abstract [en]

    It is difficult to implement predictive maintenance in the automotive industry as it looks today, since the sensor capabilities and engineering effort available for diagnostic purposes is limited. It is, in practice, impossible to develop diagnostic algorithms capable of detecting many different kinds of faults that would be applicable to a wide range of vehicle configurations and usage patterns. However, it is now becoming feasible to obtain and analyse on-board data on vehicles as they are being used. It makes automatic data-mining methods an attractive alternative, since they are capable of adapting themselves to specific vehicle configurations and usage. In order to be useful, though, such methods need to be able to detect interesting relations between a large number of available signals. This paper presents an unsupervised method for discovering useful relations between measured signals in a Volvo truck, both during normal operations and when a fault has occurred. The interesting relationships are found in a two-step procedure. In the first step, we identify a set of “good” models, by establishing an MSE threshold over the complete data set. In the second step, we estimate model parameters over time, in order to capture the dynamic behaviour of the system. We use two different approaches here, the LASSO method and the Recursive Least Squares filter. The usefulness of obtained relations is then evaluated using supervised learning to separate different classes of faults.

  • 70.
    Rögnvaldsson, Thorsteinn
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Etchells, Terence A
    School of Computing and Mathematical Sciences, Liverpool John Moores University.
    You, Liwen
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Garwicz, Daniel
    Department of Molecular Medicine and Surgery, Karolinska Institutet.
    Jarman, Ian
    School of Computing and Mathematical Sciences, Liverpool John Moores University.
    Lisboa, Paulo J G
    School of Computing and Mathematical Sciences, Liverpool John Moores University.
    How to find simple and accurate rules for viral protease cleavage specificities2009In: BMC Bioinformatics, ISSN 1471-2105, E-ISSN 1471-2105, Vol. 10, p. 149-156Article in journal (Refereed)
    Abstract [en]

    BACKGROUND:

    Proteases of human pathogens are becoming increasingly important drug targets, hence it is necessary to understand their substrate specificity and to interpret this knowledge in practically useful ways. New methods are being developed that produce large amounts of cleavage information for individual proteases and some have been applied to extract cleavage rules from data. However, the hitherto proposed methods for extracting rules have been neither easy to understand nor very accurate. To be practically useful, cleavage rules should be accurate, compact, and expressed in an easily understandable way.

    RESULTS:

    A new method is presented for producing cleavage rules for viral proteases with seemingly complex cleavage profiles. The method is based on orthogonal search-based rule extraction (OSRE) combined with spectral clustering. It is demonstrated on substrate data sets for human immunodeficiency virus type 1 (HIV-1) protease and hepatitis C (HCV) NS3/4A protease, showing excellent prediction performance for both HIV-1 cleavage and HCV NS3/4A cleavage, agreeing with observed HCV genotype differences. New cleavage rules (consensus sequences) are suggested for HIV-1 and HCV NS3/4A cleavages. The practical usability of the method is also demonstrated by using it to predict the location of an internal cleavage site in the HCV NS3 protease and to correct the location of a previously reported internal cleavage site in the HCV NS3 protease. The method is fast to converge and yields accurate rules, on par with previous results for HIV-1 protease and better than previous state-of-the-art for HCV NS3/4A protease. Moreover, the rules are fewer and simpler than previously obtained with rule extraction methods.

    CONCLUSION:

    A rule extraction methodology by searching for multivariate low-order predicates yields results that significantly outperform existing rule bases on out-of-sample data, but are more transparent to expert users. The approach yields rules that are easy to use and useful for interpreting experimental data.

  • 71.
    Rögnvaldsson, Thorsteinn
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Panholzer, Georg
    Salzburg Research Advanced Networking Center Jakob-Haringer-Str. 51111 5020, Salzburg, Austria.
    Byttner, Stefan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Svensson, Magnus
    Volvo Technology, 405 08 Goteborg, Sweden.
    A self-organized approach for unsupervised fault detection in multiple systems2008In: 19th International Conference on Pattern Recognition: (ICPR 2008) ; Tampa, Florida, USA 8-11 December 2008, Piscataway, N.J.: IEEE Press, 2008, p. 1-4Conference paper (Refereed)
    Abstract [en]

    An approach is proposed for automatic fault detection in a population of mechatronic systems. The idea is to employ self-organizing algorithms that produce low-dimensional representations of sensor and actuator values on the vehicles, and compare these low-dimensional representations among the systems. If a representation in one vehicle is found to deviate from, or to be not so similar to, the representations for the majority of the vehicles, then the vehicle is labeled for diagnostics. The presented approach makes use of principal component coding and a measure of distance between linear sub-spaces. The method is successfully demonstrated using simulated data for a commercial vehiclepsilas engine coolant system, and using real data for computer hard drives.

  • 72.
    Rögnvaldsson, Thorsteinn
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    You, Liwen
    Lund University, Department of Theoretical Physics, Lund, Sweden.
    Why neural networks should not be used for HIV-1 protease cleavage site prediction2004In: Bioinformatics, ISSN 1367-4803, E-ISSN 1367-4811, Vol. 20, no 11, p. 1702-1709Article in journal (Refereed)
    Abstract [en]

    Several papers have been published where non-linear machine learning algorithms, e.g. artificial neural networks, support vector machines and decision trees, have been used to model the specificity of the HIV-1 protease and extract specificity rules. We show that the dataset used in these studies is linearly separable and that it is a misuse of nonlinear classifiers to apply them to this problem. The best solution on this dataset is achieved using a linear classifier like the simple perceptron or the linear support vector machine, and it is straightforward to extract rules from these linear models. We identify key residues in peptides that are efficiently cleaved by the HIV-1 protease and list the most prominent rules, relating them to experimental results for the HIV-1 protease. Motivation: Understanding HIV-1 protease specificity is important when designing HIV inhibitors and several different machine learning algorithms have been applied to the problem. However, little progress has been made in understanding the specificity because nonlinear and overly complex models have been used. Results: We show that the problem is much easier than what has previously been reported and that linear classifiers like the simple perceptron or linear support vector machines are at least as good predictors as nonlinear algorithms. We also show how sets of specificity rules can be generated from the resulting linear classifiers.

  • 73.
    Samuelsson, Jim
    et al.
    Genedata GmbH, Lena-Christ-Strasse 50, 82152 Martinsried, Germany.
    Dalevi, Daniel
    Computing Science, Chalmers University of Technology, SE-412 96 Göteborg.
    Levander, Fredrik
    Department of Protein Technology, Lund University, Sölvegatan 33A.
    Rögnvaldsson, Thorsteinn
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Modular, scriptable and automated analysis tools for high-throughput peptide mass fingerprinting2004In: Bioinformatics, ISSN 1367-4803, E-ISSN 1367-4811, Vol. 20, no 18, p. 3628-3635Article in journal (Refereed)
    Abstract [en]

    A set of new algorithms and software tools for automatic protein identification using peptide mass fingerprinting is presented. The software is automatic, fast and modular to suit different laboratory needs, and it can be operated either via a Java user interface or called from within scripts. The software modules do peak extraction, peak filtering and protein database matching, and communicate via XML. Individual modules can therefore easily be replaced with other software if desired, and all intermediate results are available to the user. The algorithms are designed to operate without human intervention and contain several novel approaches. The performance and capabilities of the software is illustrated on spectra from different mass spectrometer manufacturers, and the factors influencing successful identification are discussed and quantified.

  • 74.
    Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Activity monitoring as a tool for person-centered care: preliminary report2014In: 2014 IEEE International Conference on Bioinformatics and Biomedicine (BIBM) / [ed] Huiru (Jane) Zheng, Werner Dubitzky, Xiaohua Hu, Jin-Kao Hao, Daniel Berrar, Kwang-Hyun Cho, Yadong Wang & David Gilbert, Piscataway, NJ: IEEE Press, 2014, p. 48-51Conference paper (Refereed)
    Abstract [en]

    The Person-Centered Care (PCC) paradigm advocates that instead of being the passive target of a medical intervention, patients should play an active part in their care and in the decision-making process, together with clinicians. Although new mobile and wearable technologies have created a new wave of personalized health-related applications, it is still unclear how these technologies can be used in health care institutions in order to support person-centered care. In order to investigate this matter, we undertook a pilot study aimed at determining if and how activity monitoring can support person-centered care routines for patients undergoing total hip replacement surgery. This is a preliminary report describing the methodology, preliminary results, and some practical challenges. We present here an orientation-invariant, accelerometer-based activity monitoring method, especially designed to address the requirements of monitoring in-patients in a real clinical setting. We also present and discuss some practical issues related to complying with hospital requirements and collaborating with hospital staff. © 2014 IEEE.

  • 75.
    Sant'Anna, Anita
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Wickström, Nicholas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    A Symbol-Based Approach to Gait Analysis From Acceleration Signals: Identification and Detection of Gait Events and a New Measure of Gait Symmetry2010In: IEEE transactions on information technology in biomedicine, ISSN 1089-7771, E-ISSN 1558-0032, Vol. 14, no 5, p. 1180-1187Article in journal (Refereed)
    Abstract [en]

    Gait analysis can convey important information about one’s physical and cognitive condition. Wearable inertial sensor systems can be used to continuously and unobtrusively assess gait during everyday activities in uncontrolled environments. An important step in the development of such systems is the processing and  analysis of the sensor data. This paper presents a symbol-based method used to detect the phases of gait and convey important dynamic information from accelerometer signals. The addition of expert knowledge substitutes the need for supervised learning techniques, rendering the system easy to interpret and easy to improve incrementally. The proposed method is compared to an approach based on peak-detection. A new symbol-based symmetry index is created and compared to a traditional temporal symmetry index and a symmetry measure based on cross-correlation. The symbol-based symmetry index exemplifies how the proposed method can extract more information from the acceleration signal than previous approaches

  • 76.
    Sentis, Luis
    et al.
    The University of Texas at Austin, Austin, TX, USA.
    Petersen, Josh
    The University of Texas at Austin, Austin, TX, USA.
    Philippsen, Roland
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Implementation and stability analysis of prioritized whole-body compliant controllers on a wheeled humanoid robot in uneven terrains2013In: Autonomous Robots, ISSN 0929-5593, E-ISSN 1573-7527, Vol. 35, no 4, p. 301-319Article in journal (Refereed)
    Abstract [en]

    In this work, we implement the floating base prioritized whole-body compliant control framework described in Sentis et al. (IEEE Transactions on Robotics 26(3):483–501, 2010) on a wheeled humanoid robot maneuvering in sloped terrains. We then test it for a variety of compliant whole-body behaviors including balance and kinesthetic mobility on irregular terrain, and Cartesian hand position tracking using the co-actuated (i.e. two joints are simultaneously actuated with one motor) robot’s upper body. The implementation serves as a hardware proof for a variety of whole-body control concepts that had previously been developed and tested in simulation. First, behaviors of two and three priority tasks are implemented and successfully executed on the humanoid hardware. In particular, first and second priority tasks are linearized in the task space through model feedback and then controlled through task accelerations. Postures, on the other hand, are shown to be asymptotically stable when using prioritized whole-body control structures and then successfully tested in the real hardware. To cope with irregular terrains, the base is modeled as a six degree of freedom floating system and the wheels are characterized through contact and rolling constraints. Finally, center of mass balance capabilities using whole-body compliant control and kinesthetic mobility are implemented and tested in the humanoid hardware to climb terrains with various slopes.

  • 77.
    Stasiunas, Antanas
    et al.
    Kaunas University of Technology, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bacauskiene, Marija
    Kaunas University of Technology, Lithuania.
    Miliauskas, Rimvydas
    Lithuanian University of Health Sciences, Lithuania.
    A Serial-Parallel Panoramic Filter Bank as a Model of Frequency Decomposition of Complex Sounds in the Human Inner Ear2011In: Informatica (Vilnius), ISSN 0868-4952, E-ISSN 1822-8844, Vol. 22, no 2, p. 259-278Article in journal (Refereed)
    Abstract [en]

    We consider that the outer hair cells of the inner ear together with the local structuresof the basilar membrane, reticular lamina and tectorial membrane form the primary filters (PF) ofthe second order. Taking into account a delay in transmission of the excitation signal in the cochleaand the influence of the Reissner membrane, we design a signal filtering system consisting of thePF with the common PF of the neighboring channels. We assess the distribution of the centralfrequencies of the channels along the cochlea, optimal number of the PF constituting a channel,natural frequencies of the channels, damping factors and summation weights of the outputs of thePF. As an example, we present a filter bank comprising 20 Gaussian-type channels each consistingof five PF. The proposed filtering system can be useful for designing cochlear implants based onbiological principles of signal processing in the cochlea.

  • 78.
    Stasiunas, Antanas
    et al.
    Department of Electrical and Control Equipment, Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bacauskiene, Marija
    Department of Electrical and Control Equipment, Kaunas University of Technology, Kaunas, Lithuania.
    Miliauskas, Rimvydas
    Department of Physiology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
    An adaptive panoramic filter bank as a qualitative model of the filtering system of the cochlea: The peculiarities in linear and nonlinear mode2012In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 34, no 2, p. 187-194Article in journal (Refereed)
    Abstract [en]

    Outer hair cells in the cochlea of the ear, together with the local structures of the basilar membrane, reticular lamina and tectorial membrane constitute the adaptive primary filters (PF) of the second order. We used them for designing a serial-parallel signal filtering system. We determined a rational number of the PF included in Gaussian channels of the system, summation weights of the output signals, and distribution of the PF along the basilar membrane. A Gaussian panoramic filter bank each channel of which consists of five PF is presented as an example. The properties of the PF, the channel and the filter bank operating in the linear and nonlinear modes are determined during adaptation and under efferent control. The results suggest that application of biological filtering principles can be useful for designing cochlear implants with new speech encoding strategies. © 2011 IPEM.

  • 79.
    Stasiunas, Antanas
    et al.
    Department of Applied Electronics, Kaunas University of Technology, LT-3031 Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Bacauskiene, Marija
    Department of Applied Electronics, Kaunas University of Technology, LT-3031 Kaunas, Lithuania.
    Miliauskas, Rimvydas
    Department of Physiology, Kaunas University of Medicine, LT-3000 Kaunas, Lithuania.
    Stasiuniene, Natalija
    Department of Biochemistry, Kaunas University of Medicine, LT-3000 Kaunas, Lithuania.
    Malmqvist, Kerstin
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Compression, adaptation and efferent control in a revised outer hair cell functional model2005In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 27, no 9, p. 780-789Article in journal (Refereed)
    Abstract [en]

    In the cochlea of the inner ear, outer hair cells (OHC) together with the local passive structures of the tectorial and basilar membranes comprise non-linear resonance circuits with the local and central (afferent–efferent) feedback. The characteristics of these circuits and their control possibilities depend on the mechanomotility of the OHC. The main element of our functional model of the OHC is the mechanomotility circuit with the general transfer characteristic y = k tanh(x − a). The parameter k of this characteristic reflects the axial stiffness of the OHC, and the parameter a working position of the hair bundle. The efferent synaptic signals act on the parameter k directly and on the parameter a indirectly through changes in the membrane potential. The dependences of the sensitivity and selectivity on changes in the parameters a and k are obtained by the computer simulation. Functioning of the model at low-level input signals is linear. Due to the non-linearity of the transfer characteristic of the mechanomotility circuit the high-level signals are compressed. For the adaptation and efferent control, however, the transfer characteristic with respect to the initial operating point should be asymmetrical (a > 0). The asymmetry relies on the deflection of the hair bundle from the axis of the OHC.

  • 80.
    Stasiunas, Antanas
    et al.
    Department of Applied Electronics, Kaunas University of Technology, LT-3031, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Kemesis, Povilas
    Department of Applied Electronics, Kaunas University of Technology, LT-3031, Kaunas, Lithuania.
    Bacauskiene, Marija
    Department of Applied Electronics, Kaunas University of Technology, LT-3031, Kaunas, Lithuania.
    Miliauskas, Rimvydas
    Laboratory of Neurophysiology, Kaunas University of Medicine, LT-3000, Kaunas, Lithuania.
    Stasiuniene, Natalija
    Department of Biochemistry, Kaunas University of Medicine, LT-3000, Kaunas, Lithuania.
    Malmqvist, Kerstin
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    A non-linear circuit for simulating OHC of the cochlea2003In: Medical Engineering and Physics, ISSN 1350-4533, E-ISSN 1873-4030, Vol. 25, no 7, p. 591-601Article in journal (Refereed)
    Abstract [en]

    In the present paper, referring to known characteristics of the outer hair cells functioning in the cochlea of the inner ear, a functional model of the outer hair cells is constructed. It consists of a linear feed-forward circuit and a non-linear positive feedback circuit. The feed-forward circuit reflects the contribution of local basilar and tectorial membrane areas and passive outer hair cells’ physical parameters to the forming of low-selectivity resonance characteristics. The non-linear positive feedback circuit reflects the non-linear outer hair cell signal transduction processes and the active role of efferents from the medial superior olive in altering circuit sensitivity and selectivity.

    Referring to an analytical description of the circuit model and computer simulation results, an explanation is given over the biological meaning of the outer hair cells’ non-linearities in signal transduction processes and the role of the non-linearities in achieving the following: signal compression, the dependency of circuit sensitivity and frequency selectivity upon the input signal amplitude, the compatibility of high-frequency selectivity and short transient response of the biological filtering circuits.

  • 81.
    Stasiunas, tanas
    et al.
    Kaunas University of Technology.
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Kemesis, povilas
    Kaunas University of Technology.
    Bacauskiene, Marija
    Kaunas University of Technology.
    Miliauskas, Rimvydas
    Kaunas University of Medicine.
    Stasiuniene, Natalija
    Kaunas University of Medicine.
    Malmqvist, Kerstin
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    A multi-channel adaptive nonlinear filtering structure realizingsome properties of the hearing system2005In: Computers in Biology and Medicine, ISSN 0010-4825, E-ISSN 1879-0534, Vol. 35, no 6, p. 495-510Article in journal (Refereed)
    Abstract [en]

    An adaptive nonlinear signal-filtering model of the cochlea is proposed based on the functional properties of the inner ear. The model consists of the cochlear filtering segments taking into account the longitudinal, transverse and radial pressure wave propagation. On the basis of an analytical description of different parts of the model and the results of computer modeling, the biological significance of the nonlinearity of signal transduction processes in the outer hair cells, their role in signal compression and adaptation, the efferent control over the characteristics of the filtering structures (frequency selectivity and sensitivity) are explained. © 2004 Elsevier Ltd. All rights reserved.

  • 82.
    Svensson, Magnus
    et al.
    Volvo Technology, 405 08 Göteborg, Sweden.
    Byttner, Stefan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Rögnvaldsson, Thorsteinn
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Self-organizing maps for automatic fault detection in a vehicle cooling system2008In: 4th International IEEE Conference Intelligent Systems, 2008. IS '08, Piscataway, N.J.: IEEE Press, 2008, p. 24-8-24-12Conference paper (Refereed)
    Abstract [en]

    A telematic based system for enabling automatic fault detection of a population of vehicles is proposed. To avoid sending huge amounts of data over the telematics gateway, the idea is to use low-dimensional representations of sensor values in sub-systems in a vehicle. These low-dimensional representations are then compared between similar systems in a fleet. If a representation in a vehicle is found to deviate from the group of systems in the fleet, then the vehicle is labeled for diagnostics for that subsystem. The idea is demonstrated on the engine coolant system and it is shown how this self-organizing approach can detect varying levels of clogged radiator.

  • 83.
    Svensson, Magnus
    et al.
    Volvo Technology, Sweden.
    Byttner, Stefan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Rögnvaldsson, Thorsteinn
    AASS Örebro University, Sweden.
    Vehicle Diagnostics Method by Anomaly Detection and Fault Identification Software2009In: SAE international journal of passenger cars : electronic and electrical systems, ISSN 1946-4614, Vol. 2, no 1, p. 352-358Article in journal (Refereed)
    Abstract [en]

    A new approach is proposed for fault detection. It builds on using the relationships between sensor values on vehicles to detect deviating sensor readings and trends in the system performance. However, in contrast to previous approaches based on such sensor relations, our approach uses a fleet of vehicles to define the normal conditions and relations. The relationships between the sensors are also determined automatically in a self-organized way on each vehicle, i.e. no off-line modeling is required. The proposed method is the first step in a remote diagnostics and maintenance service where error detection is done automatically, followed by a download of special purpose diagnostics software for the particular subsystem where the possible fault was detected.

  • 84.
    Svensson, Magnus
    et al.
    Volvo Technology.
    Rögnvaldsson, Thorsteinn
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Byttner, Stefan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    West, Martin
    Volvo Technology.
    Andersson, Björn
    Volvo Technology.
    Unsupervised deviation detection by GMM - A simulation study2011In: SDEMPED 2011: 8th IEEE Symposium on Diagnostics for Electrical Machines, Power Electronics & Drives : September 5-8, 2011, Bologna, Italy, Piscataway, N.J.: IEEE Press, 2011Conference paper (Refereed)
    Abstract [en]

    A new approach to improve fault detection of electrical machines is proposed. The increased usage of electrical machines and the higher demands on their availability requires new approaches to fault detection. In this paper we demonstrate that it is possible to detect a certain fault on a PMSM (Permanent Magnet Synchronous Machine) by using multiple similar motors, or a single motor, to build a norm of expected behavior by monitoring signal relations. This means that the machine is monitored in an unsupervised way. Four levels of an increased temperature in the rotor magnets have been investigated. The results are based on simulations and the signals used (for relation measurements) are available in a real motor installation. The method shows promising results in detecting two of the temperature faults. © 2011 IEEE.

  • 85.
    Svensson, Wolfgang
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Holmberg, Ulf
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Ankle-Foot-Orthosis Control in Inclinations and Stairs2008In: 2008 IEEE Conference on Robotics, Automation and Mechatronics, Piscataway, N.J.: IEEE Press, 2008, p. 301-306Conference paper (Refereed)
    Abstract [en]

    A control procedure is proposed for an ankle-footorthosis (AFO) for different gait situations, such as inclinations and stairs. This paper presents a novel AFO control of the ankle angle. A magneto-rheological damper was used to achieve ankle damping during foot down and locking at swing, thereby avoiding foot slap as well as foot drop.

    The controller used feedback from the ankle angle only. Still it was capable of not only adjusting damping within a gait step but also changing control behavior depending on level walking, ascending and descending stairs. As a consequence, toe strike was possible in stair gait as opposed to heel strike in level walking.

    Tests verified the expected behavior in stair gait and in level walking where gait speed and ground inclinations varied. The self-adjusted AFO is believed to improve gait comfort in slopes and stairs.

  • 86.
    Svensson, Wolfgang
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Holmberg, Ulf
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Estimating Ground Inclination Using Strain Sensors with Fourier Series Representation2010In: Journal of Robotics, ISSN 1687-9600, Vol. 2010, p. 1-8Article in journal (Refereed)
    Abstract [en]

    An embedded measurement system for foot orthosis during gait is proposed. Strain gauge sensors were mounted on a foot orthosis to give information about strain in the sagittal plane. The ankle angle of the orthosis was fixed and strain characteristics were therefore changed when walking on slopes. With a Fourier series representation of the strain during a gait cycle, ground angle at different walking speeds and inclinations could be estimated with similar accuracy as previous studies using kinematically based estimators. Furthermore, if the angle of the mechanical foot ankle was changed, the sensing technique still could estimate ground angle without need for recalibration as opposed to kinematical sensors. This indicates that embedded strain sensors can be used for online control of future orthoses with inclination adaptation. Also, there would be no need to recalibrate the sensing system when changing shoes with different heel heights.

  • 87.
    Svensson, Wolfgang
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Holmberg, Ulf
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Ground angle estimator from an ankle foot orthosis based on strain sensing and Fourier series2008In: IEEE International Conference on Mechatronics and Automation, 2008. ICMA 2008, Piscataway, N.J.: IEEE Press, 2008, p. 203-206Conference paper (Refereed)
    Abstract [en]

    A ground angle estimation technique for use on ankle-foot-orthosis AFO, during gait is proposed. Strain gauge sensors were mounted on a foot orthosis in order to give information about strain in the sagittal plane. The ankle angle of the orthosis was fixed. Strain characteristics were therefore changed when walking on slopes. It was investigated if strain information could be used for detection of inclination and estimation of inclination angle. With a Fourier series representation of the strain during a gait cycle, ground angle at different walking speeds and inclinations could be estimated with similar accuracy as previous studies using kinematically based estimators. This indicates that embedded strain sensors can be used for online control of future orthoses with inclination adaptation.

  • 88.
    Svensson, Wolfgang
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Salomonsson, Tommy
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Holmberg, Ulf
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Foot orthosis strain sensing in hill walking2007In: ICORR '07: 2007 IEEE 10th International Conference on Rehabilitation Robotics : June 12-15, Noordwijk, The Netherlands, Piscataway, N.J.: IEEE Press, 2007, p. 700-703Conference paper (Refereed)
    Abstract [en]

    An embedded measurement system for foot orthosis during gait is proposed. In this paper strain gauge sensors are mounted on a foot orthosis in order to give information about strain in the sagital plane. The ankle angle of the orthosis is fixed. Strain characteristics are therefore changed when walking on slopes. It is investigated if strain information can be used for detection of inclination and estimation of inclination angle. Also walking speed influence is studied. It is shown that strain sensing only gives significant information about up hill walking. At a known walking speed ground angle can be estimated for up hill walking.

  • 89.
    Taha, Walid
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Philippsen, Roland
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Modeling Basic Aspects of Cyber-Physical Systems2012In: 3rd International Workshop on Domain-Specific Languages and models for ROBotic systems (DSLRob-12), 2012Conference paper (Refereed)
    Abstract [en]

    Designing novel cyber-physical systems entails significant, costly physical experimentation. Simulation tools can enable the virtualization of experiments. Unfortunately, current tools have shortcomings that limit their utility for virtual experimentation. Language research can be especially helpful in addressing many of these problems. As a first step in this direction, we consider the question of determining what language features are needed to model cyber-physical systems. Using a series of elementary examples of cyber-physical systems, we reflect on the extent to which a small, experimental domain-specific formalism called Acumen suffices for this purpose.

  • 90.
    Taheri, Tayebeh
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Sant'Anna, Anita
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Non-Invasive Breathing Rate Detection Using a Very Low Power Ultra-wide-band Radar2014In: 2014 IEEE International Conference on Bioinformatics and Biomedicine (BIBM) / [ed] Huiru (Jane) Zheng, Werner Dubitzky, Xiaohua Hu, Jin-Kao Hao, Daniel Berrar, Kwang-Hyun Cho, Yadong Wang & David Gilbert, Piscataway, NJ: IEEE Press, 2014, p. 78-83Conference paper (Refereed)
    Abstract [en]

    In this paper we present a novel method for remote breathing detection based on ultra-wide-band (UWB) radar. This is a method that does not require any wearable sensors, making it more comfortable and convenient for users. Furthermore, because of the wall penetrating characteristics of the transmitted signal, our system is useful in emergency situations such as monitoring people who may be trapped under earthquake rubble. For our investigation we used a Novelda UWB radar that provides high processing speed and low power consumption. In this paper we present two new convolution-based methods to extract breathing rate information from the received radar signal. This method was tested on several people who were monitored while laying down on a bed. The subject's position and breathing rate were calculated. Experimental results including 20 different subjects are provided, showing that this is a viable method for monitoring breathing rate using a low-power UWB radar.

  • 91.
    Tegegne, Mekuria
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Etbaeitabari, Amir
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Analysis and Synthesis of object overlap in Microscopy Images2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    We propose a test-bed application for synthesis and analysis of multi-layeredmicroscopy data with variation in depth of focus(DOF), where we considerthe problem of detecting object overlap.For the synthesis part, the objects are elliptical in appearance with the possibilityof setting dierent parameters like noise, resolution, illumination,circularity, area and orientation.For the analysis part, the approach allows the user to set several parameters,including sensitivity for error calculation and classier type for analysis.We provide a novel algorithm that exploits the multi-layered nature of theobject overlap problem in order to improve recognition. The variation of grayvalue for each pixel in dierent depth is used as feature source for classication.The classier divides the pixels in three dierent groups: backgroundpixels, pixels in single cells and pixels in overlapping parts.We provide experimental results on the synthesized data, where we add noiseof dierent density. In non-noisy environments the performance for accuracyof overlapping positions is 93% and the performance of the missed overlapsis around 99.98% for density of 150 cells.iv

  • 92.
    Tistarelli, Massimo
    et al.
    University of Sassari, Computer Vision Laboratory, Piazza Duomo 6, 07041 Alghero, Italy.
    Bigun, Josef
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Image and vision computing journal special issue on multimodal biometrics2009In: Image and Vision Computing, ISSN 0262-8856, E-ISSN 1872-8138, Vol. 27, no 3, p. 221-221Article, review/survey (Refereed)
    Abstract [en]

    Since its beginning in 2003, the International Summer School on Biometrics proved to be a unique forum, where advanced research students and lecturers in biometrics gathered together for a full week of study in several aspects of the science and technology of biometric recognition. This special issue includes some contributions of the school lecturers and the school students.

    The papers included represent the diversity of the current issues of biometric technologies.

    Three papers are related to the use of face images in recognition, but investigate different problems. One is on the mechanisms of human face perception to define some guidelines for automatic recognition systems. The second paper proposes a novel technique for liveness detection from the face motion. The third paper addresses the face spoofing problem, proposing a methodology to improve the recognition performances despite impostor attacks.

    One paper addresses fingerprint matching, which is a classical biometric modality, but from a new perspective. In particular the modeling of fingerprint skin elasticity and distortions is discussed in detail with a view to enhance practical applications.

    Handwriting verification is addressed from a multi-modal and multi-algorithmic perspective. Two papers address the system security. The first uses multiple modalities and watermarking techniques applied to biometric templates. The last paper discusses the introduction of biometric data in e-passports, which is one of the most recent applications of biometrics.

    The school meetings have been a rare opportunity to evaluate different technological challenges and the current advances while sharing existing know-how in tutorials. The latter is important as the amount of studies have been massive in the field. However, the hope has been to give not only new insights, but also to promote the application of a research which is already mature in many respects to offer an answer to a variety of problems, ranging from security enforcement to advanced man machine interfaces.

  • 93.
    Uloza, Virgilijus
    et al.
    Department of Otolaryngology, Kaunas University of Medicine, Eiveniu 2, LT-50009 Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bacauskiene, Marija
    Department of Electrical and Control Instrumentation, Kaunas University of Technology, Kaunas, Lithuania.
    Gelzinis, Adas
    Department of Electrical and Control Instrumentation, Kaunas University of Technology, Kaunas, Lithuania.
    Pribuisiene, Ruta
    Department of Otolaryngology, Kaunas University of Medicine, Eiveniu 2, LT-50009 Kaunas, Lithuania.
    Kaseta, Marius
    Department of Otolaryngology, Kaunas University of Medicine, Eiveniu 2, LT-50009 Kaunas, Lithuania.
    Saferis, Viktoras
    Department of Physics, Mathematics and Biophysics, Kaunas University of Medicine, Kaunas, Lithuania.
    Categorizing Normal and Pathological Voices: Automated and Perceptual Categorization2011In: Journal of Voice, ISSN 0892-1997, E-ISSN 1873-4588, Vol. 25, no 6, p. 700-708Article in journal (Refereed)
    Abstract [en]

    Objectives: The aims of the present study were to evaluate the accuracy of an elaborated automated voice categorization system that classified voice signal samples into healthy and pathological classes and to compare it with classification accuracy that was attained by human experts. Material and Methods: We investigated the effectiveness of 10 different feature sets in the classification of voice recordings of the sustained phonation of the vowel sound /a/ into the healthy and two pathological voice classes, and proposed a new approach to building a sequential committee of support vector machines (SVMs) for the classification. By applying “genetic search” (a search technique used to find solutions to optimization problems), we determined the optimal values of hyper-parameters of the committee and the feature sets that provided the best performance. Four experienced clinical voice specialists who evaluated the same voice recordings served as experts. The “gold standard” for classification was clinically and histologically proven diagnosis. Results: A considerable improvement in the classification accuracy was obtained from the committee when compared with the single feature type-based classifiers. In the experimental investigations that were performed using 444 voice recordings coming from 148 subjects, three recordings from each subject, we obtained the correct classification rate (CCR) of over 92% when classifying into the healthy-pathological voice classes, and over 90% when classifying into three classes (healthy voice and two nodular or diffuse lesion voice classes). The CCR obtained from human experts was about 74% and 60%, respectively. Conclusion: When operating under the same experimental conditions, the automated voice discrimination technique based on sequential committee of SVM was considerably more effective than the human experts.

  • 94.
    Ungh, Jörgen
    et al.
    StoraEnso, Falun Research Centre, Sweden.
    Nilsson, Carl Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Analysis of paper, print and press interaction from online measurements in a press room2007In: Nordic Pulp & Paper Research Journal, ISSN 0283-2631, E-ISSN 2000-0669, Vol. 22, no 3, p. 383-387Article in journal (Refereed)
    Abstract [en]

    A measurement platform for online studies of print runnability in a full-scale four-high web offset printing press is described. Results from two trial runs showed no effect of reel tightness on print runnability. Differences were, however, found for so called edge reels.

  • 95.
    Vachkov, Gancho
    et al.
    Yamaguchi University, Yamaguchi, Japan.
    Byttner, Stefan
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Svensson, Magnus
    Volvo Group Trucks Technology, Göteborg, Sweden.
    Battery Aging Detection Based on Sequential Clustering and Similarity Analysis2012In: IS'2012: 2012 6th IEEE International Conference Intelligent Systems, Proceedings, Piscataway, N.J.: IEEE Press, 2012, p. 42-47, article id 6335112Conference paper (Refereed)
    Abstract [en]

    The battery cells are an important part of electric and hybrid vehicles and their deterioration due to aging directly affects the life cycle and performance of the whole battery system. Therefore an early aging detection of the battery cell is an important task and its correct solution could significantly improve the whole vehicle performance. This paper presents a computational strategy for battery aging detection, based on available data chunks from real operation of the vehicle. The first step is to aggregate (reduce) the original large amount of data by much smaller number of cluster centers. This is done by a newly proposed sequential clustering algorithm that arranges the clusters in decreasing order of their volumes. The next step is the proposed fuzzy inference procedure for weighed approximation of the cluster centers that creates comparable one dimensional fuzzy model for each available data set. Finally, the detection of the aged battery is treated as a similarity analysis problem, in which the pair distances between all battery cells are estimated by analyzing the predicted values from the respective fuzzy models. All these three steps of the computational procedure are explained in the paper and applied to real experimental data for battery aging detection. The results are positive and suggestions for further improvements are made in the conclusions. © 2012 IEEE.

  • 96.
    Vaiciukynas, Evaldas
    et al.
    Department of Electrical & Control Equipment, Kaunas University of Technology, Kaunas, Lithuania.
    Verikas, Antanas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Gelzinis, Adas
    Department of Electrical & Control Equipment, Kaunas University of Technology, Kaunas, Lithuania.
    Bacauskiene, Marija
    Department of Electrical & Control Equipment, Kaunas University of Technology, Kaunas, Lithuania.
    Uloza, Virgilijus
    Department of Otolaryngology, Lithuanian University of Health Sciences, Kaunas, Lithuania.
    Exploring similarity-based classification of larynx disorders from human voice2012In: Speech Communication, ISSN 0167-6393, E-ISSN 1872-7182, Vol. 54, no 5, p. 601-610Article in journal (Refereed)
    Abstract [en]

    In this paper identification of laryngeal disorders using cepstral parameters of human voice is researched. Mel-frequency cepstral coefficients (MFCCs), extracted from audio recordings of patient's voice, are further approximated, using various strategies (sampling, averaging, and clustering by Gaussian mixture model). The effectiveness of similarity-based classification techniques in categorizing such pre-processed data into normal voice, nodular, and diffuse vocal fold lesion classes is explored and schemes to combine binary decisions of support vector machines (SVMs) are evaluated. Most practiced RBF kernel was compared to several constructed custom kernels: (i) a sequence kernel, defined over a pair of matrices, rather than over a pair of vectors and calculating the kernelized principal angle (KPA) between subspaces; (ii) a simple supervector kernel using only means of patient's GMM; (iii) two distance kernels, specifically tailored to exploit covariance matrices of GMM and using the approximation of the Kullback-Leibler divergence from the Monte-Carlo sampling (KL-MCS), and the Kullback-Leibler divergence combined with the Earth mover's distance (KL-EMD) as similarity metrics. The sequence kernel and the distance kernels both outperformed the popular RBF kernel, but the difference is statistically significant only in the distance kernels case. When tested on voice recordings, collected from 410 subjects (130 normal voice, 140 diffuse, and 140 nodular vocal fold lesions), the KL-MCS kernel, using GMM with full covariance matrices, and the KL-EMD kernel, using GMM with diagonal covariance matrices, provided the best overall performance. In most cases, SVM reached higher accuracy than least squares SVM, except for common binary classification using distance kernels. The results indicate that features, modeled with GMM, and kernel methods, exploiting this information, is an interesting fusion of generative (probabilistic) and discriminative (hyperplane) models for similarity-based classification. (C) 2011 Elsevier B.V. All rights reserved.

  • 97.
    Valincius, Donatas
    et al.
    Kaunas University of Technology.
    Verikas, Antanas
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Gelzinis, Adas
    Kaunas University of Technology.
    Bacauskiene, Marija
    Kaunas University of Technology.
    Image analysis based categorization of laryngeal diseases2006In: Proceedings of the 1st International Conference on Electrical and Control Technologies, 2006, 2006, p. 300-305Conference paper (Refereed)
    Abstract [en]

    This paper concentrates on an automated analysis of laryngeal images aiming to categorize the images into three decision classes, namely healthy, nodular and diffuse. The problem is treated as an amage analysis and classification task. To obtain a comprehensive description of laryngeal images, multiple feature sets exploiting information on image colour, texture, geometry, image intensity gradient direction, and frequency content are extracted. A separate support vector machine (SVM) is used to categorize features of each type into decision classes. The final image categorization is then obtained which is based on the decisions provided by a committee of support vector machines. Bearing in mind a high similarity of the decision classes, the correct classification rate of over 94 % is obtained while testing the system on 785 laryngeal images that are recorded by the Department of Otolaryngology, Kaunas University of Medicine is rather promising.

  • 98.
    Verikas, Antanas
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bacauskiene, M.
    Department of Applied Electronics, Kaunas University of Technology, Kaunas, Lithuania.
    Dosinas, A.
    Department of Applied Electronics, Kaunas University of Technology, Kaunas, Lithuania.
    Bartkevicius, V.
    Department of Applied Electronics, Kaunas University of Technology, Kaunas, Lithuania.
    Gelzinis, A.
    Department of Applied Electronics, Kaunas University of Technology, Kaunas, Lithuania.
    Vaitkunas, M.
    Department of Applied Electronics, Kaunas University of Technology, Kaunas, Lithuania.
    Lipnickas, A.
    Department of Applied Electronics, Kaunas University of Technology, Kaunas, Lithuania.
    An intelligent system for tuning magnetic field of a cathode ray tube deflection yoke2003In: Knowledge-Based Systems, ISSN 0950-7051, E-ISSN 1872-7409, Vol. 16, no 3, p. 161-164Article in journal (Refereed)
    Abstract [en]

    This short communication concerns identification of the number of magnetic correction shunts and their positions for deflection yoke tuning to correct the misconvergence of colours of a cathode ray tube. The misconvergence of colours is characterised by the distances measured between the traces of red and blue beams. The method proposed consists of two phases, namely, learning and optimisation. In the learning phase, the radial basis function neural network is trained to learn a mapping: correction shunt position→changes in misconvergence. In the optimisation phase, the trained neural network is used to predict changes in misconvergence depending on a correction shunt position. An optimisation procedure based on the predictions returned by the neural net is then executed in order to find the minimal number of correction shunts needed and their positions. During the experimental investigations, 98% of the deflection yokes analysed have been tuned successfully using the technique proposed.

  • 99.
    Verikas, Antanas
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bacauskiene, M.
    Department of Applied Electronics, Kaunas University of Technology Kaunas, Lithuania.
    Malmqvist, Kerstin
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Learning an Adaptive Dissimilarity Measure for Nearest Neighbour Classification2003In: Neural computing & applications (Print), ISSN 0941-0643, E-ISSN 1433-3058, Vol. 11, no 3-4, p. 203-209Article in journal (Refereed)
    Abstract [en]

    In this paper, an approach to weighting features for classification based on the nearest-neighbour rules is proposed. The weights are adaptive in the sense that the weight values are different in various regions of the feature space. The values of the weights are found by performing a random search in the weight space. A correct classification rate is the criterion maximised during the search. Experimentally, we have shown that the proposed approach is useful for classification. The weight values obtained during the experiments show that the importance of features may be different in different regions of the feature space

  • 100.
    Verikas, Antanas
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Bacauskiene, Marija
    Kaunas University of Technology.
    Gelzinis, Adas
    Kaunas University of Technology.
    Uloza, Virgilijus
    Kaunas University of Medicine.
    Monitoring Human Larynx by Random Forests Using Questionnaire Data2011In: Proceedings of the 11th International Conference on Intelligent Systems Design and Applications, ISDA, Cordoba, 22-24 november, 2011, IEEE Computer Society, 2011, p. 914-919Conference paper (Refereed)
    Abstract [en]

    This paper is concerned with noninvasive monitoring of human larynx using subject’s questionnaire data. By applying random forests (RF), questionnaire data arecategorized into a healthy class and several classes of disorders including: cancerous, noncancerous, diffuse, nodular, paralysis, and an overall pathological class. The most important questionnaire statements are determined using RF variable importance evaluations. To explore multidimensional data, t-Distributed Stochastic Neighbor Embedding (t-SNE) and multidimensionalscaling (MDS) are applied to the RF data proximity matrix.When testing the developed tools on a set of data collectedfrom 109 subjects, 100% classification accuracy was obtainedon unseen data coming from two—healthy and pathological—classes. The accuracy of 80.7% was achieved when classifyingthe data into the healthy, cancerous, and noncancerous classes.The t-SNE and MDS mapping techniques facilitate data explorationaimed at identifying subjects belonging to a ”riskgroup”. It is expected that the developed tools will be of greathelp in preventive health care in laryngology.

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