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  • 151.
    Belova, Anna
    et al.
    Halmstad University, School of Information Technology.
    Shmidt, Tamara
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Ehrhardt, Matthias
    AMNA, Bergische Universität Wuppertal, Wuppertal, Germany.
    Meshfree methods in option pricing2012Conference paper (Refereed)
    Abstract [en]

    A meshfree approximation scheme based on the radial basis function (RBF) methods is presented for the numerical solution of the options pricing model. This work deals with the valuation of the European, Asian and American options. The option prices are modeled by the Black-Scholes equation. The θ-method is used to discretize the equation with respect to time. Next, the option price is approximated in space with RBF. In case of American options a penalty method is used, i.e. the free boundary is removed by adding a small and continuous penalty term to the Black-Scholes equation. Finally, we present a comparison of analytical and finite difference solutions and numerical results. © 2012 MANT.

  • 152.
    Benes, Zsofia
    Halmstad University, School of Business and Engineering (SET).
    Textilindustrins avloppsvatten och avloppsslam ur ett miljöperspektiv: Underlag för internationella riktlinjer inom projektet Sweden Textile Water Initiative2012Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The aim of my thesis is to obtain knowledge of textile wastewater and textile sludge from an environmental perspective, which can be used as a basis for the  ”Sweden Textile Water Initiative” guidelines for a sustainable sludge management. In my study I have mainly focused on textile dyes, salts and metals and their routes during wastewater treatment.This paper is partly a literature review, which I began by identifying the pollutants discharged from each textile process. Then I studied wastewater and sludge quality, environmental aspects, possible treatment and recycling methods. I have also tried to find existing type of guidelines in order to make comparisons. My thesis has a broad perspective and includes in addition to "end-of-pipe" solutions also alternative methods such as treatment of partial flow or substitution of harmful chemicals. Another important part of this study is a qualitative survey of more than 20 textile mills. The results show the extent of awareness and control on effluent and sludge issues. The survey has revealed that major improvements are needed in sludge management. Finally, I have proposed sludge guidelines at three levels, which will hopefully be helpful for STWI in evaluating their suppliers and showing a way towards a more sustainable sludge management. 

  • 153.
    Bengtsson, Conny
    Halmstad University, School of Business and Engineering (SET).
    Energianalys av luftbehandling2011Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Electricity consumption for ventilation has increased by 40% since 1990 in Sweden. Ventilation is an environmental villain since inquiries indicates that the electricity consumption for ventilation system fans can be much reduced. Reduction of electricity consumption for ventilation purposes can be achieved through e.g. the exchange of fan motors to EC motors or to fans with backward curved blades and direct drive. Such measures can provide reduced power consumption by up to 50 % in some applications.

    The ventilation fans in Sweden consume 12.3 TWh each year. Today Sweden has 175 000 ventilation systems with too high consumption of electricity and no heat recycling. According to the Swedish Energy Agency the ventilation sector has a large potential for savings and the energy consumption for ventilation could be lowered by 30 % (3,5 TWh), which roughly corresponds to the total annual wind power production in Sweden.

    The Analytical tool developed in this thesis work is designed to be user friendly and is thought to be an aid when evaluating functionality and efficiency in air treatment system. The tool analyzes data from measurements and produces key ratios which are then compared with given key ratios and standard guidelines. The Analysis tool was tested on one reference object and functioned as intended, but may at this stage be considered as a prototype that can be further developed. Specific training will be required before using the analysis tool with consideration to electrical safety and accuracy of measurement.

    This thesis work aims at evaluating the potential savings within air treatment systems in energy efficient buildings, and to develop a calculation tool to meet the demand that is likely to arise from property owners who want to save energy.

  • 154.
    Bengtsson, Jerker
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Efficient implementation of stream applications on processor arrays2006Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    This thesis concludes work conducted on exploring the usage of parallel and reconfigurable processor architectures in industrial high-performance embedded systems. This kind of systems has by tradition been built using a mix of digital signal processors and custom made hardware. Digital signal processors provide full functional felxibility, but at the cost of lower performance. Custom made hardware can be optimized for specific functions for high performance, but at the cost of inflexibility and high development costs. A desire is to combine flexibility and performance using commercial hardware, without trading too much of performance for flexibility.

    Parallel and reconfigurable architectures provide a flexible computing space constituting processing elements that are coupled through configurable communication structures. Architectures designed with less complex processing elements render a high degree of utilizable parallelism at the cost of having to use a portion of the pocessing elements for control functions. In the thesis it is shown that it is possible to utilize this kind of architecture to achieve high performance efficiency, despite the fact that a large fraction of PEs are required to implement control-oriented portions in a fairly complex algorithm.

    A major problem is that architectures of this kind expose a very complex programming abstraction for compilers and programmers. The approach taken in this work is a domain-specific stream processing model which provides means to express application-specific dataflows and computations in terms of streams. An extensive application study comprising the baseband processing in radio base stations has been used to define sufficient data types, operators and language construct. Furthermore, to support industrial requirements on portability to different architectures, it must be possible to express parallelism and characteristic computations without exposing of hardware details in the source code.

    To be able to prototype and set up experiments with stream processing languages an experimental programming framework has been developed. A first prototype language with specific primitive types, operators and stream constructs has been implemented in order to elaborate with baseband programming. It is demonstrated how these types and operators can be used to express machine-independent bit field and other fine-grained data parallel computations. Furthermore, the language has been designed with constructs for efficient and flexible programming of reconfiguration of distributed function parameters.

  • 155.
    Bengtsson, Jerker
    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).
    Intermediate representations for simulation and implementation2010In: Handbook of Signal processing systems / [ed] S.S Bhattacharyya, E.F. Deprettere, R. Leupers and J. Takala, New York: Springer-Verlag New York, 2010, 1, p. 739-767Chapter in book (Other academic)
  • 156.
    Bengtsson, Jerker
    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).
    Models and Methods for Development of DSP Applications on Manycore Processors2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Advanced digital signal processing systems require specialized high-performance embedded computer architectures. The term high-performance translates to large amounts of data and computations per time unit. The term embedded further implies requirements on physical size and power efficiency. Thus the requirements are of both functional and non-functional nature. This thesis addresses the development of high-performance digital signal processing systems relying on manycore technology. We propose building two-level hierarchical computer architectures for this domain of applications. Further, we outline a tool flow based on methods and analysis techniques for automated, multi-objective mapping of such applications on distributed memory manycore processors. In particular, the focus is put on how to provide a means for tunable strategies for mapping of task graphs on array structured distributed memory manycores, with respect to given application constraints. We argue for code mapping strategies based on predicted execution performance, which can be used in an auto-tuning feedback loop or to guide manual tuning directed by the programmer. Automated parallelization, optimisation and mapping to a manycore processor benefits from the use of a concurrent programming model as the starting point. Such a model allows the programmer to express different types and granularities of parallelism as well as computation characteristics of importance in the addressed class of applications. The programming model should also abstract away machine dependent hardware details. The analytical study of WCDMA baseband processing in radio base stations, presented in this thesis, suggests dataflow models as a good match to the characteristics of the application and as execution model abstracting computations on a manycore. Construction of portable tools further requires a manycore machine model and an intermediate representation. The models are needed in order to decouple algorithms, used to transform and map application software, from hardware. We propose a manycore machine model that captures common hardware resources, as well as resource dependent performance metrics for parallel computation and communication. Further, we have developed a multifunctional intermediate representation, which can be used as source for code generation and for dynamic execution analysis. Finally, we demonstrate how we can dynamically analyse execution using abstract interpretation on the intermediate representation. It is shown that the performance predictions can be used to accurately rank different mappings by best throughput or shortest end-to-end computation latency.

  • 157.
    Bengtsson, Jerker
    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).
    Svensson, Bertil
    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).
    A domain-specic approach for software development on manycore platforms2008Conference paper (Refereed)
    Abstract [en]

    The programming complexity of increasingly parallel processors calls for new tools that assist programmers in utilising the parallel hardware resources. In this paper we present a set of models that we have developed as part of a tool for mapping dataflow graphs onto manycores. One of the models captures the essentials of manycores identified as suitable for signal processing, and which we use as tar- get for our algorithms. As an intermediate representation we introduce timed configuration graphs, which describe the mapping of a model of an application onto a machine model. Moreover, we show how a timed configuration graph by very simple means can be evaluated using an abstract interpretation to obtain performance feedback. This infor- mation can be used by our tool and by the programmer in order to discover improved mappings.

  • 158.
    Bengtsson, Jerker
    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).
    Svensson, Bertil
    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).
    A Domain-specific Approach for Software Development on Manycore Platforms2008In: SIGARCH Computer Architecture News, ISSN 0163-5964, E-ISSN 1943-5851, Vol. 36, no 5, p. 2-10Article in journal (Refereed)
    Abstract [en]

    The programming complexity of increasingly parallel processors calls for new tools that assist programmers in utilising the parallel hardware resources. In this paper we present a set of models that we have developed as part of a tool for mapping dataflow graphs onto manycores. One of the models captures the essentials of manycores identified as suitable for signal processing, and which we use as target for our algorithms. As an intermediate representation we introduce timed configuration graphs, which describe the mapping of a model of an application onto a machine model. Moreover, we show how a timed configuration graph by very simple means can be evaluated using an abstract interpretation to obtain performance feedback. This information can be used by our tool and by the programmer in order to discover improved mappings.

  • 159.
    Bengtsson, Jerker
    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).
    Svensson, Bertil
    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).
    Manycore performance analysis using timed configuration graphs2009In: International Symposium on Systems, Architectures, Modeling, and Simulation, 2009. SAMOS '09 / [ed] Michael Joseph Schulte and Walid Najjar, Piscataway, N.J.: IEEE Press, 2009, p. 108-117Conference paper (Refereed)
    Abstract [en]

    The programming complexity of increasingly parallel processors calls for new tools to assist programmers in utilising the parallel hardware resources. In this paper we present a set of models that we have developed to form part of a tool which is intended for iteratively tuning the mapping of dataflow graphs onto manycores. One of the models is used for capturing the essentials of manycores that are identified as suitable for signal processing and which we use as target architectures. Another model is the intermediate representation in the form of a timed configuration graph, describing the mapping of a dataflow graph onto a machine model. Moreover, this IR can be used for performance evaluation using abstract interpretation. We demonstrate how the models can be configured and applied in order to map applications on the Raw processor. Furthermore, we report promising results on the accuracy of performance predictions produced by our tool. It is also demonstrated that the tool can be used to rank different mappings with respect to optimisation on throughput and end-to-end latency.

  • 160.
    Bengtsson, Jerker
    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).
    Svensson, Bertil
    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).
    Methodologies and tools for development of signal processing software on multicore platforms2008In: 2008 proceedings of the 41st Annual IEEE/ACM International Symposium on Microarchitecture: MICRO-41, November 8-12, 2008, Lake Como, Italy, Piscataway, N.J.: IEEE Computer Society, 2008, p. 2-Conference paper (Refereed)
  • 161.
    Bengtsson, Johan
    et al.
    Halmstad University, School of Education, Humanities and Social Science.
    Månsson, Erica
    Halmstad University, School of Education, Humanities and Social Science.
    Nu blir det bråk!: En litteraturstudie inom matematik med inriktning på tal i bråkform.2019Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Vissa elever anser matematik är svårt och tråkigt. Elever både i yngre och högre åldrar visar otillräckliga kunskaper vid inlärningen av tal i bråkform, vilket är ett mönster som fortsätter i skolorna. Syftet med studien var att ta reda på vad forskning säger om elevers svårigheter med och missuppfattningar av tal i bråkform, användningen av del av helhet och antal och hur tal i bråkform representeras. Resultaten visar att elever har svårigheter med vissa delar inom tal i bråk och uppfattningen av del av helhet. Den visar också att det finns olika representationer som gynnar eleverna. För vidare studier inom detta område föreslås djupare inriktning på vad det är som påverkar elevernas brister, vad som kan göras i tidig ålder samt hitta nya metoder, modeller och representationer som gynnar elever lärande inom matematik.

  • 162.
    Bengtsson, Julia
    et al.
    Halmstad University, School of Education, Humanities and Social Science.
    Gullvén, Isabell
    Halmstad University, School of Education, Humanities and Social Science.
    Multiplikation, division och dess samband2018Independent thesis Basic level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Litteraturstudien grundar sig i det faktum att vägen till förståelse för innebörden och funktionen av operationer med multiplikation och division är besvärligt för en del elever och lärare. De svenska elevernas låga resultat inom matematik från undersökningarna PISA och TIMSS är även oroande och därför är det av yttersta vikt att forska inom vilka strategier och metoder som faktiskt används i undervisningen om multiplikation, division och dess samband. Syftet med denna studie är att undersöka vad forskning beskriver om multiplikation, division och dess samband, och mer specifikt, att besvara frågeställningarna: vilka strategier och metoder beskriver forskning används i undervisning om multiplikation och division? Samt vilka strategier och metoder beskriver forskning används i undervisning om sambandet mellan multiplikation och division? För att besvara frågeställningarna och uppnå studiens syfte har vi systematiskt tagit fram, analyserat och sammanställt vetenskapliga studier som berör det valda området. Resultatet visar att den strategi som används och upphöjs mest är arrays, dock visar de olika studierna att det finns många olika metoder som lärare kan använda när de arbetar med strategin. Inom vilka strategier och metoder som används för att förklara sambandet mellan räknesätten nämns även arrays som en effektiv metod. Resultatet visar även att forskarna helst ser att man undervisar multiplikation och division tillsammans istället för isär och på så sätt visar sambandet mellan dem. Problematiseringen av resultatet i denna studie är att majoriteten av studier som använts är internationella och därför kan inte resultaten representera hur lärare i Sverige arbetar med det valda området. Vidare forskning inom området kan vara att titta på hur ett fåtal svenska lärare undervisar om sambandet. Slutsatsen för studien är att lärare är i behov av djupare kunskap inom sambandet mellan multiplikation och division och för att få det måste fler strategier och metoder inom ämnet synliggöras.

  • 163.
    Bengtsson, Lars
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS). Chalmers University of Technology, Gothenburg, Sweden.
    Linde, Arne
    Chalmers University of Technology, Gothenburg, Sweden.
    Nordström, Tomas
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS). Telecommunications Research Center Vienna (FTW), Vienna, Austria.
    Svensson, Bertil
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Taveniku, Mikael
    XCube Communication, Inc., Westford, MA, United States.
    The REMAP Reconfigurable Architecture: a Retrospective2006In: FPGA Implementations of Neural Networks, New York: Springer-Verlag New York, 2006, p. 325-360Chapter in book (Refereed)
    Abstract [en]

    The goal of the REMAP project was to gain new knowledge about the design and use of massively parallel computer architectures in embedded real-time systems. In order to support adaptive and learning behavior in such systems, the efficient execution of Artificial Neural Network (ANN) algorithms on regular processor arrays was in focus. The REMAP-β parallel computer built in the project was designed with ANN computations as the main target application area. This chapter gives an overview of the computational requirements found in ANN algorithms in general and motivates the use of regular processor arrays for the efficient execution of such algorithms. REMAP-β was implemented using the FPGA circuits that were available around 1990. The architecture, following the SIMD principle (Single Instruction stream, Multiple Data streams), is described, as well as the mapping of some important and representative ANN algorithms. Implemented in FPGA, the system served as an architecture laboratory. Variations of the architecture are discussed, as well as scalability of fully synchronous SIMD architectures. The design principles of a VLSI-implemented successor of REMAP-β are described, and the paper is concluded with a discussion of how the more powerful FPGA circuits of today could be used in a similar architecture. © 2006 Springer.

  • 164.
    Bengtsson, Magnus
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Brandt, Carl-Henrik
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Strävan mot en hållbar kommun: En fallstudie av strategisk grön IS i Varbergs kommun2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    I takt med de alltmer påtagliga miljöproblemen såsom klimatförändringar och minskning av biologisk mångfald har behovet av att agera ekologiskt hållbart blivit allt viktigare. Majoriteten av organisationer är idag eniga om att de har ett ansvar till bidragande av ett mer ekologiskt hållbart ageranade. Sveriges kommuner har ett ansvar att agera utifrån miljömål på en lokal nivå. Grön IS är ett begrepp som syftar till hur informationssystem kan stödja organisationer till att upprätta mer ekologiskt hållbara verksamhetsprocesser. Studiens syfte är att påvisa vilka strategiska orsaker som kan ligga till grund för tillämpning av grön IS för en svensk kommun. Det finns flera strategiska orsaker för organisationer att agera hållbart, i studien kartläggs ekologiska hållbarhetsstrategier och IS/IT-strategier vilka ligger till grund för grön IS-strategi. Den svenska kommunen representeras i en fallstudie av Varbergs kommun som eftersträvar att agera hållbart i sina verksamhetsprocesser. I studien har samband identifierats mellan Varberg kommuns ekologiska hållbarhetsmål och IS/IT-strategier där strategiska orsaker som effektivitet, attraktion, innovation och samverkan är anledningar att tillämpa grön IS.

  • 165.
    Bengtsson, Ola
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Baerveldt, Albert-Jan
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS).
    Localization in changing environments - Estimation of a covariance matrix for the IDC algorithm2001In: Proceedings 2001 IEEE/RSJ International Conference on Intelligent Robots and Systems. Expanding the Societal Role of Robotics in the the Next Millennium (Cat. No.01CH37180): Volume 4 of 4, Piscataway, N.J.: IEEE, 2001, p. 1931-1937Conference paper (Refereed)
    Abstract [en]

    Previously we have presented a new scan-matching algorithm, based on the IDC - Iterative Dual Correspondence- algorithm, which showed a good localization performance even in the case of severe changes in the environment. The Problem of the IDC-algorithm is that there is no good way to estimate the covariance matrix of the position estimate, which prohibits an effective fusion with other position estimates from other sensors, e.g by means of the Kalman filter. In this paper we present a new way to estimate the covariance matrix, by estimating the Hessian matrix of the error function that is minimized by the IDC scan-matching algorithm. Simulation results show that the estimated covariance matrix correspond well to the real one.

  • 166.
    Bengtsson, Ola
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Baerveldt, Albert-Jan
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS).
    Robot localization based on scan-matching - estimating the covariance matrix for the IDC algorithm2003In: Robotics and Autonomous Systems, ISSN 0921-8890, E-ISSN 1872-793X, Vol. 44, no 1, p. 29-40Article in journal (Refereed)
    Abstract [en]

    We have previously presented a new scan-matching algorithm based on the IDC (iterative dual correspondence) algorithm, which showed a good localization performance even in environments with severe changes. The problem of the IDC algorithm is that there is no good way to estimate a covariance matrix of the position estimate, which prohibits an effective fusion with other position estimates of other sensors. This paper presents two new ways to estimate the covariance matrix. The first estimates the covariance matrix from the Hessian matrix of the error function minimized by the scan-matching algorithm. The second one, which is an off-line method, estimates the covariance matrix of a specific scan, from a specific position by simulating and matching scans around the position. Simulation results show that the covariance matrix provided by the off-line method fully corresponds with the real one. Some preliminary tests on real data indicate that the off-line method gives a good quality value of a specific scan position, which is of great value in map building.

  • 167.
    Benjaminsson, Stephanie
    Halmstad University.
    THE MORPHOLOGY OF ICHNEUMONIDAE: ORTHOPLEMATINAE COLLECTED DURING SWEDISH MALAISE TREAP PROJECT: USING MRBAYERS AND TNT2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 168.
    Beohar, Harsh
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Cuijpers, Pieter
    Department of Mathematics and Computer Science, Eindhoven University of Technology, Eindhoven, The Netherlands.
    Avoiding Diamonds in Desynchronisation2014In: Science of Computer Programming, ISSN 0167-6423, E-ISSN 1872-7964, Vol. 91, no PART A, p. 45-69Article in journal (Refereed)
    Abstract [en]

    The design of concurrent systems often assumes synchronous communication between different parts of a system. When system components are physically apart, this assumption becomes inappropriate. Desynchronisation is a technique that aims to implement a synchronous design in an asynchronous manner by placing buffers between the components of the synchronous design. When queues are used as buffers, the so-called 'diamond property' (among others) ensures correct operation of the desynchronised design. However, this property is difficult to establish in practice. In this paper, we give sufficient and necessary conditions under which a concrete synchronous design (i.e., without the unobservable action) is equivalent to an asynchronous design and formally prove that the diamond property is no longer needed for desynchronisation when half-duplex queues are used as a communication buffer. Furthermore, we discuss how the half-duplex condition can be further relaxed when the diamond property can be partially guaranteed. To illustrate how this theory may be applied, we desynchronise the synchronous systems that are synthesised using supervisory control theory. © 2013 Elsevier B.V.

  • 169.
    Beohar, Harsh
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    A Pre-congruence Format for XY-simulation2015In: Fundamentals of Software Engineering: 6th International Conference, FSEN 2015 Tehran, Iran, April 22–24, 2015, Revised Selected Papers / [ed] Mehdi Dastani & Marjan Sirjani, Cham: Springer, 2015, Vol. 9392, p. 215-229Conference paper (Refereed)
    Abstract [en]

    XY-simulation is a generalization of bisimulation that is parameterized with two subsets of actions. XY-simulation is known in the literature under different names such as modal refinement, partial bisimulation, and alternating simulation. In this paper, we propose a precongruence rule format for XY-simulation. The format allows for checking compositionality of XY-simulation for an arbitrary language with structural operational semantics, by performing very simple checks on the syntactic shape of the rules. We apply our format to derive concrete compositionality results for different notions of behavioral pre-order with respect to different process calculi in the literature. © IFIP International Federation for Information Processing 2015

  • 170.
    Beohar, Harsh
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Input-output conformance testing based on featured transition systems2014In: Proceedings of the 29th Annual ACM Symposium on Applied Computing, Association for Computing Machinery (ACM), 2014, p. 1272-1278Conference paper (Refereed)
    Abstract [en]

    We extend the theory of input-output conformance testing to the setting of software product lines. In particular, we allow for input-output featured transition systems to be used as the basis for generating test suites and test cases. We introduce refinement operators both at the level of models and at the level of test suites that allow for projecting them into a specific product configuration (or a product sub-line). We show that the two sorts of refinement are consistent and lead to the same set of test-cases. © Copyright 2014 ACM

  • 171.
    Beohar, Harsh
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Input–output conformance testing for software product lines2016In: The Journal of logical and algebraic methods in programming, ISSN 2352-2208, E-ISSN 2352-2216, Vol. 85, no 6, p. 1131-1153Article in journal (Refereed)
    Abstract [en]

    We extend the theory of input-output conformance (IOCO) testing to accommodate behavioral models of software product lines (SPLs). We present the notions of residual and spinal testing. These notions allow for structuring the test process for SPLs by taking variability into account and extracting separate test suites for common and specific features of an SPL. The introduced notions of residual and spinal test suites allow for focusing on the newly introduced behavior and avoiding unnecessary re-test of the old one. Residual test suites are very conservative in that they require retesting the old behavior that can reach to new behavior. However, spinal test suites more aggressively prune the old tests and only focus on those test sequences that are necessary in reaching the new behavior. We show that residual testing is complete but does not usually lead to much reduction in the test-suite. In contrast, spinal testing is not necessarily complete but does reduce the test-suite. We give sufficient conditions on the implementation to guarantee completeness of spinal testing. Finally, we specify and analyze an example regarding the Ceiling Speed Monitoring Function from the European Train Control System. (C) 2016 The Author(s). Published by Elsevier Inc.

  • 172.
    Beohar, Harsh
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Spinal test suites for software product lines2014In: Proceedings: Ninth Workshop on Model-Based Testing (MBT 2014) / [ed] Alexander K. Petrenko, Holger Schlingloff, Sydney: Open Publishing Association , 2014, Vol. 141, p. 44-55Conference paper (Refereed)
    Abstract [en]

    A major challenge in testing software product lines is efficiency. In particular, testing a product line should take less effort than testing each and every product individually. We address this issue in the context of input-output conformance testing, which is a formal theory of model-based testing. We extend the notion of conformance testing on input-output featured transition systems with the novel concept of spinal test suites. We show how this concept dispenses with retesting the common behavior among different, but similar, products of a software product line. © H. Beohar & M.R. Mousavi.

  • 173.
    Beohar, Harsh
    et al.
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Varshosaz, Mahsa
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Mousavi, Mohammad Reza
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Basic behavioral models for software product lines: Expressiveness and testing pre-orders2016In: Science of Computer Programming, ISSN 0167-6423, E-ISSN 1872-7964, Vol. 123, p. 42-60Article in journal (Refereed)
    Abstract [en]

    In order to provide a rigorous foundation for Software Product Lines (SPLs), several fundamental approaches have been proposed to their formal behavioral modeling. In this paper, we provide a structured overview of those formalisms based on labeled transition systems and compare their expressiveness in terms of the set of products they can specify. Moreover, we define the notion of tests for each of these formalisms and show that our notions of testing precisely capture product derivation, i.e., all valid products will pass the set of test cases of the product line and each invalid product fails at least one test case of the product line. © 2015 The Authors.

  • 174.
    Bepari, Nuruzzaman
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Alam, Mohammad Zabedul
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Rahman, Md. Syadur
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Architecture of a Distributed LDAP Directory2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
  • 175.
    Beremark, Mikael
    et al.
    Halmstad University, School of Information Technology.
    Fryland, John
    Halmstad University, School of Information Technology.
    A Comparison of Intrusion Detection Systems in Home Networks2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The security in home networks is a growing concern, not in the least due to the increase in connected devices with the Internet of Things (IoT). Different types of Intrusion Detection Systems (IDS’s) exists with various system requirements. This thesis will research and compare two of these, Bro and Snort IDS in order to determine their functionality in a low resource environment such as a Raspberry Pi. In order to measure functionality and performance, several experiments have been conducted such as penetration testing and thorough installation and configuration experiments.

  • 176.
    Berg, Alexander
    et al.
    Lund University, Lund, Sweden.
    Yazdi, Sadegh
    Technical University of Denmark, Lyngby, Denmark.
    Nowzari, Ali
    Lund University, Lund, Sweden.
    Storm, Kristian
    Lund University, Lund, Sweden.
    Jain, Vishal
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), MPE-lab. Lund University, Lund, Sweden.
    Vainorius, Neimantas
    Lund University, Lund, Sweden.
    Samuelson, Lars
    Lund University, Lund, Sweden.
    Wagner, Jakob B.
    Technical University of Denmark, Lyngby, Denmark.
    Borgström, Magnus T.
    Lund University, Lund, Sweden.
    Radial Nanowire Light-Emitting Diodes in the (AlxGa1-x)yIn1-yP Material System2016In: Nano letters (Print), ISSN 1530-6984, E-ISSN 1530-6992, Vol. 16, no 1, p. 656-662Article in journal (Refereed)
    Abstract [en]

    Nanowires have the potential to play an important role for next-generation light-emitting diodes. In this work, we present a growth scheme for radial nanowire quantum-well structures in the AlGaInP material system using a GaInP nanowire core as a template for radial growth with GaInP as the active layer for emission and AlGaInP as charge carrier barriers. The different layers were analyzed by X-ray diffraction to ensure lattice-matched radial structures. Furthermore, we evaluated the material composition and heterojunction interface sharpness by scanning transmission electron microscopy energy dispersive X-ray spectroscopy. The electro-optical properties were investigated by injection luminescence measurements. The presented results can be a valuable track toward radial nanowire light-emitting diodes in the AlGaInP material system in the red/orange/yellow color spectrum. © 2015 American Chemical Society.

  • 177.
    Berg, Martin
    Halmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Man and Information technology laboratory (MI-lab).
    Smart jewellery: measuring the unknown2016Conference paper (Refereed)
    Abstract [en]

    Self-tracking devices and apps often measure and provide interpretations of personal data in a rather straightforward way, for instance by visualising the speed and distance of a run or the quality of sleep during a night. There is however a growing number of devices that take the data analysis further by providing insights and algorithmic advices about domains of our lives that are otherwise thought of as difficult to grasp. This paper explores two devices of this kind, namely the Moodmetric and the ŌURA which are two recently released smart rings with associated mobile apps that claim to measure emotions and rest, promote happiness and help users to perform better. Whereas several studies have shed light over how users engage with self-tracking apps and devices, little attention has been paid to how these technologies stem from dreams, hopes and imaginaries of designers and developers. This paper approaches self-tracking from a producer perspective in order to frame how users and their everyday lives are imagined by designers and how these assumptions are built into the technologies. Empirically, the paper is based on a content analysis of blog posts, marketing materials and user guides from the ŌURA and Moodmetric companies along with video interviews with company representatives as well as recordings of their public appearances. Engaging with the field of software studies as well as the emerging field of self-tracking studies, this paper aims at providing a basis for further design oriented studies of self-tracking.

  • 178.
    Berg, Stina
    et al.
    Halmstad University, School of Information Technology.
    Lilja Sjökrans, Elisabet
    Halmstad University, School of Information Technology.
    Load Imbalance Detection for an Induction Motor: - A Comparative Study of Machine Learning Algorithms2019Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In 2016 the average industry downtime cost was estimated to $260.000 every hour, and with Swedish industries being an important part of the national economy it would be desirable to reduce the amount of unplanned downtime to a minimum. There are currently many different solutions for system supervision for monitoring system health but none which analyse data with machine learning in an industrial gateway.

     

    The aim for this thesis is to test, compare and evaluate three different algorithms to find a classifier suitable for a gateway environment. The evaluated algorithms were Random Forest, K-Nearest Neighbour and Linear Discriminant Analysis. Load imbalance detection was used as a case study for evaluating these algorithms. The gateway received data from a Modbus ATV32 frequency converter, which measured specific features from an induction motor. The imbalance was created with loads that were attached on a fly-wheel at different angles to simulate different imbalances. The classifiers were compared on their accuracy, memory usage, CPU usage and execution time. The result was evaluated with tables, confusion matrices and AUC- ROC curves.  Although all algorithms performed well LDA was best based on the criteria set.

  • 179.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    A Pipelined Ring Network - Heterogeneous Real-time in Radar Signal Processing2003In: Applied Informatics: AI 2003, ACTA Press , 2003, p. 825-832Conference paper (Refereed)
    Abstract [en]

    The paper presents results of simulations done with the CCR-EDF (Control Channel based Ring network with EDF scheduling) pipelined ring network together with a case study of system area networks for radar signal processing. The topology of the network is a pipelined unidirectional fibre-ribbon ring that supports several simultaneous transmissions in non-overlapping segments. Access to the network is divided into slots. In each slot the node that has the highest priority message is permitted to transmit. This feature of the medium access protocol gives the network the functionality for earliest deadline first scheduling. Different classes of traffic are supported for the user. These are guaranteed logical real-time channels (LRTC), best effort (BE) channels and non real-time (NRT) traffic. The case study used is from an airborne radar signal processing (RSP) application. Results of the simulations indicate that the CCR-EDF network works well with the RSP application studied.

  • 180.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Analysis problems in a spatial reuse ring network with a simple clocking strategy2002Report (Other academic)
    Abstract [en]

    This technical report describes the problems associated with analysis of a spatial reuse ring network with a clock strategy also used in previously studied ring networks. The aim for the analysis was to find the worst case deterministic throughput. Some results are achieved and are presented. A worst case bound is found and this can be used for analysing feasibility of message connection sets. However, the bound is pessimistic and does not utilise the bandwidth reuse features of the network. This result does not meet the expectations that where foreseen because the medium access method inherently supports distributed global deadline scheduling. It is concluded that the current clock strategy of the network is the cause of the problems. It is also concluded that the analysis is complicated by the clocking strategy and that by introducing small changes in the network (will be presented in a separate paper), the analysis of the real-time performance will be much simpler. This will lead to a network with less pessimistic assumptions and hence better support for real-time traffic.

  • 181.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Fibre-ribbon ring network with inherent support for earliest deadline first message scheduling2002In: Proceedings: International Parallel and Distributed Processing Symposium : April 15-19, 2002, Ft. Lauderdale, Florida, USA, Los Alamitos, Calif.: IEEE , 2002, p. 157-163, article id 1016235Conference paper (Refereed)
    Abstract [en]

    This paper presents a network with earliest deadline first (EDF) scheduling on a per slot basis. The network is called CCR-EDF (Control Channel based Ring network with EDF scheduling). The topology is a pipelined unidirectional fibre-ribbon ring that supports several simultaneous transmissions in non-overlapping segments and with dedicated fibres for clock and arbitration. In each slot the node that has highest priority generates the clock. The clock hand over strategy together with the scheduling feature gives the network the functionality for earliest deadline scheduling of periodic messages belonging to logical real-time connections. Logical realtime connections may be added and removed during runtime, through admission control. Guaranteed realtime communication service is supported to the user. Other services include best effort traffic and special services for parallel and distributed processing such as barrier synchronisation and global reduction.

  • 182.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Gördén, Bengt
    SUNET/KTH-NOC.
    Åhlander, Anders
    Ericsson Microwave Systems.
    Heterogeneous real-time services in high-performance system area networks - application demands and case study definitions2002Report (Other academic)
    Abstract [en]

    To be able to verify the feasibility of high-performance networks, it is essential to evaluate them according to specific application requirements. At the same time, specifications of quite general, or understandable, application requirements are needed for the ability to make repeated analyses on different networks. Especially, heterogeneous real-time requirements must be defined to be able to analyze networks to be used in future applications. In this report, we introduce two application fields where system area networks (SANs) supporting heterogeneous real-time services are highly desirable if not required: radar signal processing and large IP routers. For each application field, a case study with heterogeneous real-time communication requirements is defined. No case studies are presented in this report. Instead, they are defined for later evaluations to determine how suitable networks are for applications with heterogeneous real-time communication requirements.

  • 183.
    Bergenhem, Carl
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Jonsson, Magnus
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Olsson, Jörgen
    VoIvo Technological Development Corporation, Göteborg, Sweden .
    Fibre-ribbon pipeline ring network with distributed global deadline scheduling and deterministic user services2001In: International Conference on Parallel Processing Workshops, 2001, Los Alamitos: IEEE Computer Society , 2001, p. 311-318, article id 951967Conference paper (Refereed)
    Abstract [en]

    This paper introduces a novel, fair medium access protocol for a pipelined optical ring network. The protocol provides global deadline scheduling of packets. Requests for sending packets are sent by the nodes in the network to a master node. The master uses the deadline information in the requests to determine which packet is most urgent. Arbitration is done in two steps, the collection and distribution phases. The protocol is therefore called two-cycle medium access (TCMA). The network is best suited for LANs and SANs (system area networks) such as a high speed network in a cluster of computers or in an embedded parallel computer. Offered services in this network include best effort messages, guarantee seeking messages, real-time virtual channels, functions used in parallel processing. These are possible without additional higher level protocols. A simulation analysis of the network with the protocol is presented. Further analysis shows minimum slot length and fairness of the protocol.

  • 184.
    Berger, Christian
    et al.
    University of Gothenburg, Gothenburg, Sweden.
    Mousavi, Mohammad RezaHalmstad University, School of Information Technology, Halmstad Embedded and Intelligent Systems Research (EIS), Centre for Research on Embedded Systems (CERES).
    Cyber Physical Systems. Design, Modeling, and Evaluation: 5th International Workshop, CyPhy 2015, Amsterdam, The Netherlands, October 8, 2015, Proceedings2015Collection (editor) (Refereed)
  • 185.
    Berggren, Thomas
    Halmstad University, School of Business, Engineering and Science, Biological and Environmental Systems (BLESS), Bioscience.
    Does type of habitat affect tick-burden in roe deer (Capreolus capreolus) neonates?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This study was investigating the relationships between: 1) habitat type and tick abundance, 2) habitat type and tick load on fawns, and 3) tick load and fawn survival. During two years and in two study areas, 105 fawns (57 fawns in Bogesund and 48 fawns in Grimsö) have been captured by hand and equipped with a radio-transmitter. The fawns’ positions have then been triangulated almost every day until they died or had at least 30 positions. The surviving fawns were recaptured when they were estimated to have a weight of 3.6 kg. Ticks were collected from the fawns during both the capture and the recapture. By using the flagging-method, in which a white sheet is dragged along the ground, ticks were also collected from the vegetation. A vegetation map was used to determine the habitat on transects and the home range of the fawns. The study areas showed different results regarding in which habitat the ticks were found. At Grimsö ticks seems to favor deciduous forest and mixed forest not on mires. At Bogesund the favored tick habitat was instead coniferous forest with trees between five to fifteen meters. In Bogesund there was a positive correlation between tick-burden and percent of coniferous forest on lichen-dominated areas that covered fawn home ranges. No relationship could be found between ticks and the survival of the fawns. A positive correlation between surviving days and tick load during first capture could instead be found on fawns that died within 30 days.

  • 186.
    Berglund, Björn
    et al.
    Linköping University, Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping, Sweden.
    Khan, Ghazanfar Ali
    Department of Chemistry, Umeå University, Umeå, Sweden.
    Weisner, Stefan
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Ehde, Per Magnus
    Halmstad University, School of Business and Engineering (SET), Biological and Environmental Systems (BLESS), Wetland Research Centre.
    Fick, Jerker
    Department of Chemistry, Umeå University, Umeå, Sweden.
    Lindgren, Per-Eric
    Linköping University, Division of Medical Microbiology, Department of Clinical and Experimental Medicine, Linköping, Sweden.
    Efficient removal of antibiotics in surface-flow constructed wetlands, with no observed impact on antibiotic resistance genes2014In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 476-477, p. 29-37Article in journal (Refereed)
    Abstract [en]

    Recently, there have been growing concerns about pharmaceuticals including antibiotics as environmental contaminants. Antibiotics of concentrations commonly encountered in wastewater have been suggested to affect bacterial population dynamics and to promote dissemination of antibiotic resistance. Conventional wastewater treatment processes do not always adequately remove pharmaceuticals causing environmental dissemination of low levels of these compounds. Using constructed wetlands as an additional treatment step after sewage treatment plants have been proposed as a cheap alternative to increase reduction of wastewater contaminants, however this means that the natural microbial community of the wetlands becomes exposed to elevated levels of antibiotics. In this study, experimental surface-flow wetlands in Sweden were continuously exposed to antibiotics of concentrations commonly encountered in wastewater. The aim was to assess the antibiotic removal efficiency of constructed wetlands and to evaluate the impact of low levels of antibiotics on bacterial diversity, resistance development and expression in the wetland bacterial community. Antibiotic concentrations were measured using liquid chromatography-mass spectrometry and the effect on the bacterial diversity was assessed with 16S rRNA-based denaturing gradient gel electrophoresis. Real-time PCR was used to detect and quantify antibiotic resistance genes and integrons in the wetlands, during and after the exposure period. The results indicated that the antibiotic removal efficiency of constructed wetlands was comparable to conventional wastewater treatment schemes. Furthermore, short-term treatment of the constructed wetlands with environmentally relevant concentrations (i.e. 100-2000 ng x 1(-1)) of antibiotics did not significantly affect resistance gene concentrations, suggesting that surface-flow constructed wetlands are well-suited for wastewater treatment purposes. (c) 2014 Elsevier B.V. All rights reserved.

  • 187.
    Bergman, Lars
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Intelligent systems (IS-lab).
    Using multicoloured halftone screens for offset print quality monitoring2005Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    In the newspaper printing industry, offset is the dominating printing method and the use of multicolour printing has increased rapidly in newspapers during the last decade. The offset printing process relies on the assumption that an uniform film of ink of right thickness is transferred onto the printing areas. The quality of reproduction of colour images in offset printing is dependent on a number of parameters in a chain of steps and in the end it is the amount and the distribution of ink deposited on the substrate that create the sensation and thus the perceived colours. We identify three control points in the offset printing process and present methods for assessing the printing process quality in two of these points:

    • Methods for determining if the printing plates carry the correct image

    • Methods for determining the amount of ink deposited onto the newsprint

    A new concept of colour impression is introduced as a measure of the amount of ink deposited on the newsprint. Two factors contribute to values of the colour impression, the halftone dot-size and ink density. Colour impression values are determined on gray-bars using a CCD-camera based system. Colour impression values can also be determined in an area containing an arbitrary combination of cyan magenta and yellow inks. The correct amount of ink is known either from a reference print or from prepress information. Thus, the deviation of the amount of ink can be determined that can be used as control value by a press operator or as input to a control system.

    How a closed loop controller can be designed based on the colour impression values is also shown.

    It is demonstrated that the methods developed can be used for off-line print quality monitoring and ink feed control, or preferably in an online system in a newspaper printing press.

  • 188.
    Bergman, Lars
    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).
    Intelligent Monitoring of the Offset Printing Process2004In: Proceedings of the IASTED International Conference on Neural Networks and Computational Intelligence, ACTA Press, 2004, p. 173-178Conference paper (Refereed)
    Abstract [en]

    In this paper, we present a neural networks and image analysis based approach to assessing colour deviations in an offset printing process from direct measurements on halftone multicoloured pictures--there are no measuring areas printed solely to assess the deviations. A committee of neural networks is trained to assess the ink proportions in a small image area. From only one measurement the trained committee is capable of estimating the actual amount of printing inks dispersed on paper in the measuring area. To match the measured image area of the printed picture with the corresponding area of the original image, when comparing the actual ink proportions with the targeted ones, properties of the 2-D Fourier transform are exploited.

  • 189.
    Bergman, Lars
    et al.
    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).
    Bacauskiene, M.
    Department of Applied Electronics, Kaunas University of Technology.
    Unsupervised colour image segmentation applied to printing quality assessment2005In: Image and Vision Computing, ISSN 0262-8856, E-ISSN 1872-8138, Vol. 23, no 4, p. 417-425Article in journal (Refereed)
    Abstract [en]

    We present an option for colour image segmentation applied to printing quality assessment in offset lithographic printing by measuring an average ink dot size in halftone pictures. The segmentation is accomplished in two stages through classification of image pixels. In the first stage, rough image segmentation is performed. The results of the first segmentation stage are then utilized to collect a balanced training data set for learning refined parameters of the decision rules. The developed software is successfully used in a printing shop to assess the ink dot size on paper and printing plates.

  • 190.
    Bergman, Lina
    Halmstad University, School of Business and Engineering (SET).
    Gullrisbock (Phytoecia nigricornis) i grus- och sandtäkter i Halland.2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This dissertation is done as a preparatory step for the action plan of environmental protection shall issue to preserve the Phytoecia nigricornis in the country when it is red-listed and classified as vulnerable (VU). My task was to investigate the prevalence of the Phytoecia nigricornis in Halland County. They wanted to see if it existed in Halland (Ehnström, 1999). If it did not exist they wanted to know how to improve its habitat.

    the Phytoecia nigricornis is difficult to inventory because when it is larvae it lives in the roots and lower parts of the trunk of the Solidago Virgaurea plant and the adult beetles only keeps to Solidago Virgaurea by mating and egg laying and larval caterpillars when they hatch (Bily, 1989; Molander, 1999). Often it is overlooked or missed, and one question was whether it existed  in the whole country or only in those parts where it was previously found in, Skåne, Blekinge and Östergötland (Ehnström, 1999).

    One problem for the Phytoecia nigricornis is that their habitats is declining. Because the gravel and sand is an ending resource which means that today more and more go on to find materials that will replace the gravel and sand. Gravel and sand pits are closed and then gets overgrown which means that the Solidago Virgaurea is outcompeted by other stronger plants.

    In early May, the beginning of the plan of the thesis and inventory were made. Premises suitable for the inventory was investigated and eventually was 16 of them elected. 9 of these facilities would, in the County Administrative Board's previous inventories have Solidago Virgaurea. Once the premises had been selected an inventory protocol were formed (Appendix 5) where information of the premises would be noted such as the weather and so on. The first inventory were outcarried on June 13th. The premises that contained Solidago Virgaurea were inventoried twice each and the other only once. The last inventory  was conducted on July 6th. The inventories were carried out during this period because it is during this time Phytoecia nigricornis lay their eggs on Solidago Virgaurea and that's when you can find them in one place at the same time. None of the inventories was carried out when it rained or blew over small breezes because  under these conditions Phytoecia nigricornis is  hiding. After the inventories were compiled information was collected and then the report was written. No Phytoecia nigricornis were found during the inventories.

  • 191.
    Bergquist, Magnus
    Institut för tillämpad informationsteknologi, Göteborgs universitet, Göteborg, Sverige.
    Hoax - sociala virus på Internet2010In: Kulturelle processer i Europa: indlaeg fra den 29. Nordiske etnolog- og folkloristkongres, København: Museum Tusculanums Forlag, 2010, p. 151-160Chapter in book (Refereed)
  • 192.
    Bergquist, Magnus
    IT-universitetet, Göteborgs universitet, Göteborg, Sverige.
    iDentity: Identitetsskapande i Macvärlden2006In: Vardagslivets fronter / [ed] Kerstin Gunnemark & Magnus Mörck, Göteborg: Arkipelag, 2006, p. 125-143Chapter in book (Refereed)
  • 193.
    Bergquist, Magnus
    et al.
    Göteborg University.
    Hafström, Carolina
    Hofbauer, Jessica
    Global Discourse and Local Practice: A study of the Role of Open Source Software in SchoolNet Namibia2005Conference paper (Refereed)
  • 194.
    Bergquist, Magnus
    et al.
    Gothenburg University, Sweden.
    Ihlström Eriksson, Carina
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Man and Information technology laboratory (MI-lab).
    Ljungberg, Jan
    Gothenburg University, Sweden.
    Åkesson, Maria
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE), Halmstad Embedded and Intelligent Systems Research (EIS), Man and Information technology laboratory (MI-lab).
    Combining Actor Network Theory and Genre Theory to Understand the Evolution of Digital Genres2008In: Proceedings of JAIS Theory Development Workshop, Amsterdam: Sprouts Alliance , 2008, p. 36-Conference paper (Refereed)
    Abstract [en]

    In this paper we argue that a combination of Actor-Network Theory (ANT) and Genre Theory can constitute a theoretical framework for understanding how digital genres evolve. Genre theory states that genres evolve over time through reciprocal interaction between institutionalized practices and individual action; that they develop from actors’ responses to recurrent situations, and are shaped around characteristics as content, form, functionality and purpose. Genres emerge out of practice and at the same time they shape that practice. While genre theory can describe the characteristics of a genre, it cannot handle the process of how a genre is formed and what powers and forces are involved in this shaping process. In order to address this problem, several authors have incorporated structuration theory into genre analysis. However, structuration theory can only catch these constitutional processes of genre in a very broad manner. As a genre is evolving and stabilizing over time in interplay with different actors, it goes beyond what is possible to explain only by means of structuration theory. Instead, ANT could work as a tool to capture the process of how a genre takes form in negotiations with different stakeholders. In this paper we discuss how genre theory and ANT can be combined in a framework for analyzing emerging genres. We apply this theoretical framework on an e-newspaper project that embodies a new genre in the making. We will here show how evolving genre characteristics are developed, formed and stabilized in a negotiation and struggle between the involved actors when they translate their interests in ways that finally are resulting in a new genre.

  • 195.
    Bergquist, Magnus
    et al.
    University of Gothenburg, Gothenburg, Sweden.
    Ljungberg, Jan
    University of Gothenburg, Gothenburg, Sweden.
    Tales from the Crypt – Organizing IT-Business in the Dotcom era2005In: Proceedings of the IRIS28 / [ed] Eli Hustad, Björn E. Munkvold, Knut Rolland & Leif S. Flak, Kristiansand: IRIS Association , 2005Conference paper (Refereed)
    Abstract [en]

    In this paper we report on a narrative study aimed at capturing consultants’ experiences of mergers – from an organizational and cultural perspective – during the so-called dotcom era. In the paper we focus on the problems that resulted from mergers between firms with totally different views on what it means to organize IT-business. The mergers studied led to cultural clashes in how to organize IT-projects, like different ways of managing, organizing, working, collaborating and experiencing the organization, but also implicit practices like dress-code, attitudes, lifestyle, norms and values. The empirical data is collected with the help of storytelling session where consultants tell stories about own experiences or stories that they have heard from colleagues. Stories are presented and discussed related to different themes, such as values, practices, culture/identity, and business models. We propose that these experiences of failed acquisitions and mergers embed important knowledge of the practices and problems of the organizing of IT-businesses.

  • 196.
    Bergquist, Magnus
    et al.
    University of Gothenburg.
    Ljungberg, Jan
    University of Gothenburg.
    Rolandsson, Bertil
    University of Gothenburg.
    Justifying the Value of Open Source2012In: ECIS 2012 Proceedings: Paper 122, Association for Information Systems, 2012Conference paper (Refereed)
    Abstract [en]

    Over the last decade, free and open source software (FOSS) has gradually become recognized by different actors in society outside FOSS communities and increasingly integrated in corporate software development, challenging proprietary software practices and establishing new open source companies. Literature describing this transition is focusing a narrow view on the value of using FOSS, mainly understanding it as an efficient alternative to established models for software development. This is not sufficient to fully understand the uptake of FOSS into companies. In order to gain a deeper understanding of this, there is a need to articulate a wider range of different values associated with FOSS and how they interplay in the intersection of corporations and movements. To do this we propose the order of worth framework developed by French sociologist Luc Boltanski and colleagues, which focus on the arrangements of value logics as an analytical strategy to understand how values form strong or weak arrangements in processes of institutionalization. By applying the framework on key texts from the free and open source software movement as well as on a an interview study with professional software developers employed by firms, we set out to identify how values associated with FOSS become justificatory arrangements that give legitimacy to FOSS and how these arrangements change over time, from the early free software movement to the emergent uptake of FOSS in contemporary professional software development. By understanding how justificatory logics come to play and interplay, corporations that want to adopt FOSS can better manage their engagement in FOSS activities. Keywords: Free and Open Source Software, Orders of Worth, Justification logics, Value of Open Source.

  • 197.
    Bergquist, Magnus
    et al.
    University of Gothenburg.
    Ljungberg, Jan
    University of Gothenburg.
    Rolandsson, Bertil
    University of Gothenburg.
    Spaces of Accountability: Understanding Worth in Distributed Innovation Work2012Conference paper (Refereed)
    Abstract [en]

    As a result of various driving forces, R&D and innovation processes are increasingly opened up for external influences and resources. This has lead to a changing nature of innovation work to become more distributed, networked and fragmented. In companies, a consequence of this is that hierarchically defined directives are transformed to lateral agreements. For the employee, a consequence of this is that they are increasingly expected to justify the value of distributed innovation practices in relation to both their firm and external contributors of innovation, and by doing so they involve themselves in a process were accountability is horizontally redistributed. In order to analyze this process, we use a case of open source software development, were developers from eleven firms, using open source in their professional practice, are interviewed. We show how distributed innovation processes leave the professional developer with the responsibility to select and assure that external resources becomes advantageous to their work, and how they use different types of justification to account for the value of this appropriation. We identify how different spaces of accountability are formed, potentially leading to tensions between different logic of worth. Keywords: distributed innovation, developers, logic of justification, tensions, accountability

  • 198.
    Bergquist, Magnus
    et al.
    University of Gothenburg.
    Ljungberg, Jan
    University of Gothenburg.
    Rolandsson, Bertil
    University of Gothenburg.
    The Worth of Opening up Developmental Work: Justifying a New Business Driven Spirit of Open Source Software Development2011Conference paper (Refereed)
    Abstract [en]

    Free and open source software development (FOSS) used to be associated with an ideologically driven movement built around communities of voluntary members, organizing resistance against proprietary software development. Today, however, software firms perceive FOSS as a source of innovation. Previous research has investigated what this change has meant to movement driven FOSS, but we still need more knowledge about the professional programmers and their way of organize business driven open source software development in their daily practice. This article investigates the interpretative guidelines or justifying arrangement that guide their use of FOSS. The analysis is based on 30 interviews that were done during 2008-2009 with programmers who were employed either by software firms that had come to a point where they started to adopt open source, or by firms that always based their business on open source software development. Theoretical concepts that were used in the analysis mainly derive from the economic sociology of Luc Boltanski and Laurent Thevénot, and the results indicate the emergence of a new spirit of business driven open source, consisting of a combination of different justificatory logics. This new spirit is described as an arrangement guiding how professional programmers in today’s software industry perceive the worth of using open source code in their developmental work.

  • 199.
    Bergquist, Magnus
    et al.
    Institutionen för tillämpad informationsteknologi, Göteborgs universitet, Göteborg, Sverige.
    Remneland Wikhamn, Björn
    Företagsekonomiska institutionen, Management & Organisation, Göteborgs universitet, Göteborg, Sverige.
    Ljungberg, Jan
    Institutionen för tillämpad informationsteknologi, Göteborgs universitet, Göteborg, Sverige.
    Kuschel, Jonas
    Institutionen för tillämpad informationsteknologi, Göteborgs universitet, Göteborg, Sverige.
    Generativity in open innovation ecosystem: the case of iPhone and Android2012In: Perspectives on Supplier Innovation: Theories, Concepts and Empirical Insights on Open Innovation and the Integration of Suppliers / [ed] Alexander Brem & Joe Tidd, Singapore: World Scientific, 2012, p. 617-650Chapter in book (Refereed)
  • 200.
    Bergquist, Magnus
    et al.
    University of Gothenburg.
    Rolandsson, Bertil
    University of Gothenburg.
    Restricting or releasing passion for innovation: The case of professional open source software development2012Conference paper (Refereed)
    Abstract [en]

    Companies are seeking methods to become more innovative. One strategy is to introduce disruption to promote innovation. An example of this is the uptake of Open Source Software (OSS) technologies, methods and mindsets by commercially driven actors. Contrary to the firm, open source is associated with hackers driven by a passion emerging out of a community or peer based innovation model. The fact that these hackers are highly engaged in collaboration outside the limits of the organisation, have meant that companies start to perceive them as potential resources enabling them to extend their innovative capacity. The passionate hacker is seen as an autonomous and positive disruptive force that can promote innovation for the company. This paper is based on an interview study with 30 software developers from ten companies that have chosen to introduce OSS as a vehicle for innovation. Theoretically, passion is understood as an urge to develop high quality software beyond the demarcations of the firm; it is a matter of craft or art, and the paper focuses on how this perception of the passionate hacker guides these professional developers at work. Thus, it is analysed how the discourse on the passionate hacker is transformed when it is adopted by developers working in a firm that expects organisational commitment. By studying the reshaping of these software developers’ practices, we show how OSS passion for disruptive innovation is transformed in a professional work environment, but also how disruption creates new demarcations when open source ‘culture of passion’ is introduced in firms.

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