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  • 151.
    Alfredsson, Marcus
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Lundmark, Eric
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Workflow graph editing and visualization in HTML5 and Javascript2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Being able to run applications written in a single language on multiple platforms is a strong incentive for migrating applications to the web. This along with the possibility to avoid the sometimes problematic procedure of installing software, makes the case even stronger. This thesis investigates how to migrate a workflow graph editing system into a web technology in order to publish it on the web. We will evaluate a number of different technologies such as WebGL, HTML5 canvas and SVG. SVG is deemed as the preferred technology due to its advantages when it comes to interaction. As it can leverage JavaScripts event system we get a potent way of handling events without writing a single line of code. When combining this with the framework D3JS we achieve a great tool for writing workflow management systems.

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  • 152.
    Algergawy, Alsayed
    et al.
    Friedrich Schiller University Jena, Germany.
    Cheatham, Michelle
    Wright State University, USA.
    Faria, Daniel
    Instituto Gulbenkian de Ciencia, Lisbon, Portugal.
    Ferrara, Alfio
    Universita degli studi di Milano, Italy.
    Fundulaki, Irina
    FORTH, Greece.
    Harrow, Ian
    Pistoia Alliance Inc., USA.
    Hertling, Sven
    University of Mannheim, Germany.
    Jimenez-Ruiz, Ernesto
    Alan Turing Institute, London, UK; University of Oslo, Norway.
    Karam, Naouel
    Fraunhofer FOKUS, Berlin, Germany.
    Khiat, Abderrahman
    Freie Universität Berlin, Germany.
    Lambrix, Patrick
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    Li, Huanyu
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Montanelli, Stefano
    Universita degli studi di Milano, Italy.
    Paulheim, Heiko
    University of Mannheim, Germany.
    Pesquita, Catia
    Universidade de Lisboa, Portugal.
    Saveta, Tzanina
    FORTH, Greece.
    Schmidt, Daniela
    Pontifical Catholic University of Rio Grande do Sul, Brazil.
    Shvaiko, Pavel
    Trentino Digitale SpA, Trento, Italy.
    Splendiani, Andrea
    Pistoia Alliance Inc., USA.
    Thiéblin, Elodie
    IRIT & Université Toulouse II, Toulouse, France.
    Trojahn, Cassia
    IRIT & Université Toulouse II, Toulouse, France.
    Vatascinova, Jana
    University of Economics, Prague, Czech Republic.
    Zamazal, Ondrej
    University of Economics, Prague, Czech Republic.
    Zhou, Lu
    Wright State University, USA.
    Results of the Ontology Alignment Evaluation Initiative 20182018In: Proceedings of the 13th International Workshop on Ontology Matching: co-located with the 17th International Semantic Web Conference (ISWC 2018) / [ed] Pavel Shvaiko, Jérôme Euzenat, Ernesto Jiménez-Ruiz, Michelle Cheatham, Oktie Hassanzadeh, Aachen, Germany: CEUR Workshop Proceedings , 2018, Vol. 2288, p. 76-116Conference paper (Refereed)
    Abstract [en]

    The Ontology Alignment Evaluation Initiative (OAEI) aims at comparing ontology matching systems on precisely defined test cases. These test cases can be based on ontologies of different levels of complexity (from simple thesauri to expressive OWL ontologies) and use different evaluation modalities (e.g., blind evaluation, open evaluation, or consensus). The OAEI 2018 campaign offered 12 tracks with 23 test cases, and was attended by 19 participants. This paper is an overall presentation of that campaign.

  • 153.
    Algergawy, Alsayed
    et al.
    Friedrich Schiller University Jena, Germany .
    Faria, Daniel
    BioData.pt, INESC-ID, Lisbon, Portugal .
    Ferrara, Alfio
    Universita degli studi di Milano, Italy .
    Fundulaki, Irini
    Institute of Computer Science-FORTH, Heraklion, Greece .
    Harrow, Ian
    Pistoia Alliance Inc., USA .
    Hertling, Sven
    University of Mannheim, Germany .
    Jimenez-Ruiz, Ernesto
    City University of London, UK and University of Oslo, Norway .
    Karam, Naouel
    Fraunhofer FOKUS, Berlin, Germany .
    Khiat, Abderrahmane
    Fraunhofer IAIS, Sankt Augustin, Bonn, Germany.
    Lambrix, Patrick
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, The Institute of Technology.
    Li, Huanyu
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Montanelli, Stefano
    Universita degli studi di Milano, Italy .
    Paulheim, Heiko
    University of Mannheim, Germany.
    Pesquita, Catia
    LASIGE, Faculdade de Ciencias, Universidade de Lisboa, Portugal .
    Saveta, Tzanina
    Institute of Computer Science-FORTH, Heraklion, Greece .
    Shvaiko, Pavel
    TasLab, Trentino Digitale SpA, Trento, Italy .
    Splendiani, Andrea
    Pistoia Alliance Inc., USA.
    Thieblin, Elodie
    IRIT & Universite Toulouse II, Toulouse, France .
    Trojahn, Cassia
    IRIT & Universite Toulouse II, Toulouse, France .
    Vatascinova, Jana
    University of Economics, Prague, Czech Republic .
    Zamazal, Ondrej
    University of Economics, Prague, Czech Republic .
    Zhou, Lu
    Kansas State University, USA .
    Results of the Ontology Alignment Evaluation Initiative 20192019In: Proceedings of the 14th International Workshop on Ontology Matchingco-located with the 18th International Semantic Web Conference (ISWC 2019) / [ed] Pavel Shvaiko, Jérôme Euzenat, Ernesto Jiménez-Ruiz, Oktie Hassanzadeh, Cássia Trojahn,, Aachen: CEUR Workshop Proceedings , 2019, p. 46-85Conference paper (Refereed)
    Abstract [en]

    The Ontology Alignment Evaluation Initiative (OAEI) aims at comparing ontology matching systems on precisely defined test cases. These test cases can be based on ontologies of different levels of complexity (from simple thesauri to expressive OWL ontologies) and use different evaluation modalities (e.g., blind evaluation,open evaluation, or consensus). The OAEI2019 campaign offered 11 tracks with 29 test cases, and was attended by 20 participants. This paper is an overall presentation of that campaign.

  • 154.
    Algotsson, Daniel
    Linköping University, Department of Computer and Information Science.
    Konstruktion av en databas till stöd för kassaflödesvärdering: Construction of a database to support information management for discounted cash flow valuation of corporations2005Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    When a discounted cash flow valuation is performed, the value of the asset is determined by summarising the predicted cash flows and discounting them with the cost of capital. Due to the fact that the future cash flows are predictions, a valuation is always affected by uncertainty. In order to improve the accuracy of the predictions, an extensive amount of information is used. To be successful, it is important to collect reliable and relevant information and manage the information in an efficient way. At present it is difficult to gather and manage information and sufficient computer aid is missing. The purpose of this master thesis is to construct a proposal for a database to support information management for discounted cash flow valuation of corporations. The thesis is conducted with a qualitative research method. An extensive frame of reference is presented in order to give the reader the possibility to get to know both databases and cash flow valuations.

    The result of the study is a conceptual model as well as a logical and physical database model. The proposed database consists of 20 tables where the database relationships connect the value creating factors of the corporation. Possible positive effects of the database are simplified deriving of the corporate value and capacity to store and manage greater amounts of information in a logical manner. The database can also improve the flexibility and adjust the valuation to the dynamic nature of the corporation. Furthermore, the identification of risks and risk factors can be improved. A potential problem with the database is the risk of storing irrelevant information. It can also be difficult to prove a sufficient validity for the database since no user valuation has been carried out.

    In the thesis, the author also argues that the database can be utilised for discounted cash flow valuation of any corporation. However, some tables, attributes and relationships need to be changed and adjusted to the specific nature of the corporation.

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  • 155.
    Algvere, Ebba
    Linköping University, Department of Computer and Information Science.
    Att designa effektivt lärande med blandade lärmiljöer: Hur lärmiljöer och dess aktiviteter inom blandade lärmiljöer påverkar kunskapsutveckling och förtroende för organisationen2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Denna studie har undersökt hur olika lärmiljöer inom ett utbildningsupplägg med blandade lärmiljöer skiljer sig i upplevelse, kunskapsutveckling samt förtroende. Vidare har studien undersökt om det finns någon skillnad mellan grupper, med prefererad ordning på lärmiljöer inom ett utbildningsupplägg med blandade lärmiljöer, och prefererad inläringsstil. Fyra olika inläringsstilar, av Honey och Mumford (2000), har använts i studien. Frågeställningarna har undersökts och besvarats genom en triangulering, en kombination av kvalitativa och kvantitativa metoder. Kvalitativ data har samlats in genom semistrukturerade intervjuer och har sedan följt en tematisk analysprocess. Kvantitativ data har erhållits genom ett frågeformulär som sedan har analyserats med statistiska tester. Resultaten från den kvalitativa intervjudelen har visat på att olika lärmiljöer, e-lärande och föreläsning, skiljer sig samt kompletterar varandra med avseende på upplevelse, kunskapsutveckling och förtroende för arbetsgivare. Kvantitativa resultat från frågeformulär har visat på att det inte finns någon signifikant skillnad mellan grupper, som föredrar att börja ett utbildningsupplägg med blandade lärmiljöer med olik första lärmiljö, och styrka i prefererad inläringsstil. Detta innebär att det inte finns någon direkt koppling mellan föredragen ordning på lärmiljöer inom blandade lärmiljöer och prefererad inläringsstil. Denna studie har studerat ett kunskapsgap för hur blandade lärmiljöer bör struktureras. Studiens fynd kan därmed bidra till en bättre förståelse för hur framtida utbildningsupplägg med blandade lärmiljöer bör designas för effektivt lärande och maximal kunskapsutveckling.

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  • 156.
    Alhola, Sini
    Linköping University, Department of Computer and Information Science.
    Unraveling interaction between tinnitus symptoms, cognitive abilities, and mental disorders2019Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    Based on the former studies, there is evidence of tinnitus being associated with performance on cognitive ability tests (for example Andersson et al. 2009, Hallam et al. 2004). The topic of my bachelor thesis was to unravel how depression, stress and anxiety connected with tinnitus symptoms are related to cognitive abilities such as verbal fluency, inhibition ability and working memory capacity. In order to fill an existing gap of knowledge, the relationship of different severity of stress caused by tinnitus symptoms as measured with Tinnitus Handicap Inventory (THI) and cognitive abilities and depression and anxiety symptoms was emphasized.

    The experiment group was divided into two subgroups, those with lower and higher level of perceived tinnitus severity and the differences in test scores between groups were investigated with one-way analysis of variance. As a result, significant differences between the two tinnitus patient groups were found in the level of performance in inhibition task where participants were asked to give the font color of congruent color - word pair as an answer. It was also studied whether there were correlations between perceived severity of tinnitus symptoms, depression and anxiety symptoms, working memory capacity and inhibition ability. As a result of correlation analysis, this study confirmed the connection between tinnitus symptoms and anxiety and depression symptoms found in previous studies, and a significant correlation was found between THI scores and anxiety symptoms, and THI scores and C inhibition test scores where the participant was asked to name the font color from incongruent color-word pairs. The results of this study suggest that there is a connection between the level of perceived tinnitus severity and the ability to name font color of incongruent color - word pair. The current study found no evidence about the connection between THI scores and other cognitive abilities as well as anxiety and depression symptoms, even though the THI scores correlated with both anxiety symptom scores and with the reaction times of an inhibition task where the participants were asked to point out the font color from incongruent color - word pairs.

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  • 157.
    Alhowaidi, Mohammad
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, The Institute of Technology.
    Real-Time Systems with Radiation-Hardened Processors: A GPU-based Framework to Explore Tradeoffs2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Radiation-hardened processors are designed to be resilient against soft errorsbut such processors are slower than Commercial Off-The-Shelf (COTS)processors as well significantly costlier. In order to mitigate the high costs,software techniques such as task re-executions must be deployed together withadequately hardened processors to provide reliability. This leads to a huge designspace comprising of the hardening level of the processors and the numberof re-executions of each task in the system. Each configuration in this designspace represents a tradeoff between processor load, reliability and costs.

    The reliability comes at the price of higher costs due to higher levels of hardeningand performance degradation due to hardening or due to re-executions.Thus, the tradeoffs between performance, reliability and costs must be carefullystudied. Pertinent questions that arise in such a design scenario are — (i)how many times a task must be re-executed and (ii) what should be hardeninglevel? — such that the system reliability is satisfied.

    In order to evaluate such tradeoffs efficiently, in this thesis, we proposenovel framework that harnesses the computational power of Graphics ProcessingUnits (GPUs). Our framework is based on a system failure probabilityanalysis that connects the probability of failure of tasks to the overall systemreliability. Based on characteristics of this probabilistic analysis as well asreal-time deadlines, we derive bounds on the design space to prune infeasiblesolutions. Finally, we illustrate the benefits of our proposed framework withseveral experiments

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  • 158.
    Ali, Akhtar
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Comparative study of parallel programming models for multicore computing2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Shared memory multi-core processor technology has seen a drastic developmentwith faster and increasing number of processors per chip. This newarchitecture challenges computer programmers to write code that scales overthese many cores to exploit full computational power of these machines.Shared-memory parallel programming paradigms such as OpenMP and IntelThreading Building Blocks (TBB) are two recognized models that offerhigher level of abstraction, shields programmers from low level detailsof thread management and scales computation over all available resources.At the same time, need for high performance power-ecient computing iscompelling developers to exploit GPGPU computing due to GPU's massivecomputational power and comparatively faster multi-core growth. Thistrend leads to systems with heterogeneous architectures containing multicoreCPUs and one or more programmable accelerators such as programmableGPUs. There exist dierent programming models to program these architecturesand code written for one architecture is often not portable to anotherarchitecture. OpenCL is a relatively new industry standard framework, de-ned by Khronos group, which addresses the portability issue. It oers aportable interface to exploit the computational power of a heterogeneous setof processors such as CPUs, GPUs, DSP processors and other accelerators.

    In this work, we evaluate the eectiveness of OpenCL for programmingmulti-core CPUs in a comparative case study with two CPU specic stableframeworks, OpenMP and Intel TBB, for ve benchmark applicationsnamely matrix multiply, LU decomposition, image convolution, Pi value approximationand image histogram generation. The evaluation includes aperformance comparison of the three frameworks and a study of the relativeeects of applying compiler optimizations on performance numbers.OpenCL performance on two vendor-dependent platforms Intel and AMD,is also evaluated. Then the same OpenCL code is ported to a modern GPUand its code correctness and performance portability is investigated. Finally,usability experience of coding using the three multi-core frameworksis presented.

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  • 159.
    Ali, Akhtar
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Dastgeer, Usman
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Kessler, Christoph
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    OpenCL for programming shared memory multicore CPUs2011In: Fourth Swedish Workshop on Multi-Core Computing MCC-2011: November 23-25, 2011, Linköping University, Linköping, Sweden / [ed] Christoph Kessler, Linköping: Linköping University , 2011, Vol. S. 65-70, p. 65-70Conference paper (Other academic)
    Abstract [en]

    In this work, we evaluate the effectiveness of OpenCL for programming multicore CPUs in a comparative case study with OpenMP and Intel TBB for five benchmark applications: matrix multiply, LU decomposition, 2D image convolution, Pi value approximation and image histogram generation.

  • 160.
    Ali, Akhtar
    et al.
    Linköping University, The Institute of Technology.
    Dastgeer, Usman
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Kessler, Christoph
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    OpenCL for programming shared memory multicore CPUs2012In: Proceedings of the 5th Workshop on MULTIPROG2012 / [ed] E. Ayguade, B. Gaster, L. Howes, P. Stenström, O. Unsal, HiPEAC Network of Excellence , 2012Conference paper (Refereed)
    Abstract [en]

    Shared memory multicore processor technology is pervasive in mainstream computing. This new architecture challenges programmers to write code that scales over these many cores to exploit the full computational power of these machines. OpenMP and Intel Threading Building Blocks (TBB) are two of the popular frameworks used to program these architectures. Recently, OpenCL has been defined as a standard by Khronos group which focuses on programming a possibly heterogeneous set of processors with many cores such as CPU cores, GPUs, DSP processors. In this work, we evaluate the effectiveness of OpenCL for programming multicore CPUs in a comparative case study with OpenMP and Intel TBB for five benchmark applications: matrix multiply, LU decomposition,2D image convolution, Pi value approximation and image histogram generation. The evaluation includes the effect of compiler optimizations for different frameworks, OpenCL performance on different vendors’ platformsand the performance gap between CPU-specific and GPU-specific OpenCL algorithms for execution on a modern GPU. Furthermore, a brief usability evaluation of the three frameworks is also presented.

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  • 161.
    Ali, Asif
    et al.
    Linköping University, Department of Computer and Information Science.
    Ramzan, Faheem
    Linköping University, Department of Computer and Information Science.
    Analysis and Monitoring of Team Collaboration in Emergency Response Training supported by a Web Based Information Management System2009Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    Our objective in this thesis work is to analyze and manage the log files which are generated after a number of experiments series on different groups using C3Fire simulation environment. It includes analyzing and extracting information from log files, and then maintaining this information in a database. This should be presented with a web interface through ICEfaces Ajax framework for Java. Log Files are generated after a number of experiments series on the different groups. All sequences and information related to task performed by team in group is organized in session log files. The work is divided into different steps; first step is to analyze and extract data from log files, and properly arrange it in several different tables in a database, for this MySQL database is used to store the information. The web interface of log file management system is implemented using ICEfaces Ajax framework, and is based on the statistics of log files generated from the C3Fire environment.  User would be able to add/remove the log files, also can view or edit the details of each session log file in database through web interface. Different events can be generated, and logged for the session information.

    C3Fire is an environment that supports training and research in team collaboration. The environment is mainly used in command, control and communication research, and in training of team decision making. Many humanitarian relief operations are doing their work without having any practice. When some disaster events occur, they cannot perform their jobs effectively. Effective and efficient relief operation is the need of humanity; even that’s not enough to move teams to the disaster place at right time; communication and co-ordination among the team members is the big factor to make effective and well-organized work. C3Fire is a simulation system which provides the training for team members to handle such type of disaster events, and makes the work more proficient at that time by doing effective coordination.

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  • 162.
    Alirezaie, Marjan
    Linköping University, Department of Computer and Information Science.
    Semantic Analysis Of Multi Meaning Words Using Machine Learning And Knowledge Representation2011Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    The present thesis addresses machine learning in a domain of naturallanguage phrases that are names of universities. It describes two approaches to this problem and a software implementation that has made it possible to evaluate them and to compare them.

    In general terms, the system's task is to learn to 'understand' the significance of the various components of a university name, such as the city or region where the university is located, the scienti c disciplines that are studied there, or the name of a famous person which may be part of the university name. A concrete test for whether the system has acquired this understanding is when it is able to compose a plausible university name given some components that should occur in the name.

    In order to achieve this capability, our system learns the structure of available names of some universities in a given data set, i.e. it acquires a grammar for the microlanguage of university names. One of the challenges is that the system may encounter ambiguities due to multi meaning words. This problem is addressed using a small ontology that is created during the training phase.

    Both domain knowledge and grammatical knowledge is represented using decision trees, which is an ecient method for concept learning. Besides for inductive inference, their role is to partition the data set into a hierarchical structure which is used for resolving ambiguities.

    The present report also de nes some modi cations in the de nitions of parameters, for example a parameter for entropy, which enable the system to deal with cognitive uncertainties. Our method for automatic syntax acquisition, ADIOS, is an unsupervised learning method. This method is described and discussed here, including a report on the outcome of the tests using our data set.

    The software that has been implemented and used in this project has been implemented in C.

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  • 163.
    Alirezaie, Marjan
    et al.
    Institutionen för naturvetenskap och teknik , Örebro Universitet.
    Hammar, Karl
    Högskolan i Jönköping, JTH, Datateknik och informatik.
    Blomqvist, Eva
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Nyström, Mikael
    Linköping University, Department of Biomedical Engineering, Division of Biomedical Engineering. Linköping University, Faculty of Science & Engineering.
    Ivanova, Valentina
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    SmartEnv Ontology in E-care@home2018In: SSN 2018 - Semantic Sensor Networks Workshop: Proceedings of the 9th International Semantic Sensor Networks Workshopco-located with 17th International Semantic Web Conference (ISWC 2018) / [ed] Maxime Lefrançois, Raúl Garcia Castro, Amélie Gyrard, Kerry Taylor, CEUR-WS , 2018, Vol. 2213, p. 72-79Conference paper (Refereed)
    Abstract [en]

    In this position paper we briefly introduce SmartEnv ontology which relies on SEmantic Sensor Network (SSN) ontology and is used to represent different aspects of smart and sensorized environments. We will also talk about E-carehome project aiming at providing an IoT-based health-care system for elderly people at their homes. Furthermore, we refer to the role of SmartEnv in Ecarehome and how it needs to be further extended to achieve semantic interoperability as one of the challenges in development of autonomous health care systems at home.

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    SmartEnv Ontology in E-care@home
  • 164.
    Al-kfairy, Mousa
    Linköping University, Department of Computer and Information Science.
    Toward Agile development methods & Non-functional requirements2009Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    In this thesis, we tried to solve those problems by adapting agile development methods with Non-functional requirements-framework (NFR-Framework).

    In this thesis, we have inspected many research papers, and we have met industrial experts for feedback regarding our theoretical results.

    As a result of the inspection, we have been able to adapt agile development methods (extreme programming (XP)) with NFR-framework. We use XP since it is more practically oriented process than other agile development methods.

    In the first try for this process model, we got three alternatives for applying it. The first one is based on collecting all NFRs from the beginning of the development process. The second one is based on updating the SIG (software interdependency graph) every time we have new functional requirements (FR) and the third one is based on the incremental nature of agile development methods.

    Each one of these alternatives has it is own advantages and disadvantages. We tried to extract those advantages and disadvantages by brainstorming and reading research papers. The most important issue in all of the three alternatives is the applicability. Finally we got industrial feedback regarding all of them.

    As a result of the industrial feedback, we were able to find another alternative of how to apply the process model which is presented in 7.2.

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  • 165.
    Allard, Olof
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Arts and Sciences.
    Katastrofisk design: Ett designförslag för en digital scenarioeditor2014Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Målet med det här arbetet var att skapa en konceptuell designprototyp för en scenarioeditor åt en digital version av utbildningsverktyget Emergo Train System. Rapporten ämnar ta upp och presentera den arbetsprocess som lett fram till designprototypen och dess utvärdering. I rapporten tillkommer även en diskussion kring hur en scenarioeditor bör utformas för att stödja skapandet av ETS-scenarion samt hur ett flexibelt arbetssätt stöds i form av skapandet av scenariorepresentationer.

    Intervjuer genomfördes med instruktörer och systemansvarige för ETS, samt observationer av iordningställande av ett ETS-scenario. Datainsamlingen analyserades och resulterade i en kravspecifikation för den digitala scenarioeditorn. Den prototyp som utformades gjordes så i pappersformat och utvärderades tillsammans med personal från Katastrofmedicinskt centrum i Linköping. 

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  • 166.
    Allmér, Caroline
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Arts and Sciences.
    Utvärdering av en interaktiv brand- och räddningsinstruktion genom tematisk analys baserad på användarintervjuer och heuristisk utvärdering2013Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Syftet med rapporten är att utvärdera en interaktiv brand- och räddningsinstruktion som framförallt används inom försvarsmakten. Utvärderingen gick ut på att ta reda på hur användarna använder instruktionen och hur de vill att den ska utvecklas i framtiden för att möta deras behov. Utvärderingen genomfördes genom intervjuer med sju användare från olika delar av landet samt en heuristisk utvärdering utifrån Nielsens tio användbarhetsprinciper och med hänsyn till Sweller och Chandlers ”cognitive load theory”. Resultatet visade att instruktionen framförallt används som uppslagsbok och att användarna vill se en utveckling av instruktionen där den blir större och omfattar mer information, till exempel om haverier och utländska luftfartyg och att text och illustrationer i instruktionen är uppdaterad och korrekt. Utifrån analysen togs flertalet utvecklingsförslag fram och presenteras i slutet av rapporten.

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    utvardering av en interaktiv brand och raddningsinstruktion
  • 167.
    Alm, Helen
    Linköping University, Department of Computer and Information Science.
    Duk i buk: Functional Resonance Accident Model i en vårdrelaterad kontext2008Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Ett stort antal människor dör på grund av skador som de fått inom vården och som hade kunnat förebyggas. Det finns siffror som pekar på att dessa vårdskador överskrider antalet döda i trafiken. Vid Östergötlands landsting finns sedan år 2005 en fast enhet som arbetar med patientsäkerhet. En av deras uppgifter är att, tillsammans med berörd verksamhet, utföra händelseanalyser inför anmälningar av Lex Maria-fall. Den analysmetod som används av patientsäkerhetsenheten är uppbyggd på en epidemiologisk olycksmodell.

    Syftet med denna studie har varit att använda analysmetoden FRAM (Functional Resonance Accident Model), som är en systemisk analysmetod utarbetad av Erik Hollnagel, i en vårdrelaterad kontext, någonting som inte har gjorts tidigare. FRAM har applicerats på en händelse under en operation då material glömdes kvar i patientens buk. Samtidigt har patientsäkerhetsenheten analyserat samma händelse med sin metod. En jämförelse mellan de två olika analysmetodernas slutsatser har gjorts.

    För insamling av information om arbetet i operationssal har en triangulering av observation, intervjuer med sakkunniga och genomgång av viss dokumentation genomförts. De personer som varit inblandade i den aktuella händelsen har intervjuats av patientsäkerhetsenhetens analysteam. När de båda analyserna var genomförda ordnades en fokusgrupp med diskussion kring analysmetoder.

    Studien har visat att FRAM kan vara lämplig för tillämpning på vårdskador. Det finns fördelar med en systemisk analysmetod som FRAM då den i större utsträckning speglar den omfattande komplexitet som, i detta fall, en operationssal och dess omgivning består av. Detta medför dock att analysprocessen blir mer omfattande och krävande. I dagsläget används landstingets analysmetod av ett stort antal människor efter en relativt kort utbildning, vilket skulle vara svårt att genomföra med FRAM. Det är även tydligt att mer forskning behövs då FRAM är en relativt ny analysmetod under utveckling.

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  • 168.
    Alm, Johan
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Utveckling av 2D matematikpusselspel med Phaser.io2015Independent thesis Basic level (degree of Bachelor), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    Det finns idag många verktyg och ramverk för att utveckla spelapplikationer. I den här rapporten kommer jag utvärdera Phaser.io som är ett öppen källkodsramverk för att utveckla webspelsapplikationer.

    Resultatet av det här examensarbetet är en prototyp av spelet Equamem som jag har utvecklat utifrån min handledare Erik Berglunds spelkoncept och design. Equamem är en HTML5 webspelsprototyp utvecklat med ramverket Phaser.io med HTML5 och JavaScript.

    I rapporten kommer jag gå igenom olika designval som gjorts och itererats under spelprototypens versioner av utveckling. Jag kommer även utforska hur man utvecklar ett intressant och lättlärt matematikpusselspel.

    Rapporten kommer innehålla information om Phaser.io, vad det är och vad det erbjuder för funktionalitet och hur jag har använt det i utvecklingen av Equamem. Jag kommer gå igenom fördelar och nackdelar med att använda ramverkets funktioner och utvärdera hur väl lämpat det har för att utveckla spel som Equamem.

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  • 169.
    Alm, Therese
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, Faculty of Science & Engineering.
    Design av en användarvänlig Androidapplikation för trådlös kommunikation med Electronic Control Unit för bil eller testmiljö2015Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    This thesis has been carried out within the program Bachelor of Computer Science and Engineering at Linköping University in the spring of 2015 performed at the request of ArcCore in Linköping. The aim is to create and design a user friendly Android application which wirelessly can communicate with the electronic control units in a car or test environment.

    The Android application consists of five main screens, four whose task is to print the information travelling on the CAN bus. The five screens are start, fault codes, sensors, ECU Extract and overview. Start will take you to the other screens. Fault codes, print all the fault codes, sensors prints all sensors, the ECU extract prints all information and overview displays a virtual dashboard. User Evaluations have been conducted to develop both the design and layout of the application. The development process is executed by using extreme programming and the evaluations have been carried out with the help of traditional usability tests and binary success. The evaluations feedback has been used to develop both the design and the user friendliness of the application.

    The application has been developed in the Android Studio and communicates with the ECUs using a PEAK PCAN Wireless Gateway which is connected to the Hercules Development Kit TMS570 MCU.

    The result is that we can clearly see that the ease of use has increased during the development process and that we now by using evaluations have a nice and easy user-friendly Android application that can be used by all who wants to get the information available on the CAN bus.

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  • 170.
    Alm, Torbjörn
    et al.
    Linköping University, Department of Management and Engineering, Industrial ergonomics. Linköping University, The Institute of Technology.
    Kovordányi, Rita
    Linköping University, Department of Computer and Information Science, CSELAB - Cognitive Systems Engineering Laboratory. Linköping University, The Institute of Technology.
    Ohlsson, Kjell
    Linköping University, Department of Management and Engineering, Industrial ergonomics. Linköping University, The Institute of Technology.
    Continuous versus Situation-dependent Night Vision Presentation in Automotive Applications2006Conference paper (Refereed)
    Abstract [en]

    As the number of advanced driver assistance systems in modern cars increases the question of possible negative behavioral adaptation is raised. We have investigated this phenomenon for night vision systems in a driving simulator. One common opinion is that there is a risk for using the enhanced visual conditions that come with these systems to increase speed during nighttime driving and thereby eliminate the safety margins the system was designed to provide. In our study two system approaches were compared, one with continuous presentation and one with presentation only when dangerous objects were detected by the system. The latter approach was meant to minimize the risk of negative adaptation, which was partly confirmed in the study. Moreover, the results showed better and more consistent driver performance with the situation-dependent system and all subjects preferred this approach from a workload perspective.

  • 171.
    Alm, Torbjörn
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Industrial Ergonomics.
    Ohlsson, Kjell
    Linköping University, The Institute of Technology. Linköping University, Department of Mechanical Engineering, Industrial Ergonomics.
    Kovordanyi, Rita
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, CSELAB - Cognitive Systems Engineering Laboratory.
    Glass Cockpit Simulators - Tools for IT-based Car Systems Design and Evaluation2005Conference paper (Refereed)
  • 172.
    Almgren, Kristian
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Arts and Sciences.
    Dubbeldokumentation i patientjournalen: varför sker det?2013Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [sv]

    Landstinget i Östergötland har problem med ständigt växande informationsmängder i patienters journaler. Anledningen till att detta är ett problem är att journalen blir svår att överblicka vilket gör det svårt för exempelvis läkare och sjuksköterskor att snabbt hitta relevant information och skaffa sig en uppfattning om patientens sjukdomshistoria vid exempelvis patientmottagning. Informationsöverflödet gör patientjournalen ostrukturerad och därmed svår att söka i. Det tar lång tid att hitta specifika data som eftersöks vilket kan leda till frustration och irritation i den redan tidsmässigt pressade arbetsdagen. Enligt tidigare studie är dubbeldokumentation i patientjournalen en stor bidragande faktor till detta problem. Syftet med denna studie är att undersöka varför problemet uppstår, dvs. orsaken till dubbeldokumentation.

    Både observation och intervju har använts som datainsamlingsmetod. Data har sedan analyserats med tematisk analys.

    Studien resulterade i sex olika teman; The Efficiency-Thoroughness Trade-Off Principle (ETTO), Strategier, Uppdatering och Bekräftelse, Dubbeldokumentation, Störningar, Artefakter.

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  • 173.
    Almgren, Magnus
    et al.
    Department of computer science and engineering, Chalmers university of technology, Gothenburg.
    Andersson, Peter
    FOI, Swedish Defence Research Agency, Linköping, Sweden.
    Björkman, Gunnar
    Stockholms stad / Kungliga Tekniska Högskolan, KTH, Stockholm.
    Ekstedt, Mathias
    Industrial Information and Control Systems, Royal Institute of Technology, KTH, Stockholm.
    Hallberg, Jonas
    FOI, Swedish Defence Research Agency, Linköping, Sweden.
    Nadjm-Tehrani, Simin
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Westring, Eric
    FOI, Swedish Defence Research Agency, Linköping, Sweden.
    RICS-el: Building a National Testbed for Research and Training on SCADA Security2019In: Critical Information Infrastructures Security: 13th International Conference, CRITIS 2018, Kaunas, Lithuania, September 24-26, 2018, Revised Selected Papers / [ed] Eric Luiijf, Inga Žutautaitė and Bernhard Hämmerli, Springer, 2019, p. 219-225Chapter in book (Refereed)
    Abstract [en]

    Trends show that cyber attacks targeting critical infrastructures are increasing, but security research for protecting such systems are challenging. There is a gap between the somewhat simplified models researchers at universities can sustain contra the complex systems at infrastructure owners that seldom can be used for direct research. There is also a lack of common datasets for research benchmarking. This paper presents a national experimental testbed for security research within supervisory control and data acquisition systems (SCADA), accessible for both research training and experiments. The virtualized testbed has been designed and implemented with both vendor experts and security researchers to balance the goals of realism with specific research needs. It includes a real SCADA product for energy management, a number of network zones, substation nodes, and a simulated power system. This environment enables creation of scenarios similar to real world utility scenarios, attack generation, development of defence mechanisms, and perhaps just as important: generating open datasets for comparative research evaluation.

  • 174.
    Almquist, Mathias
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Almquist, Viktor
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    A study on Android games: 3G energy consumption, CPU-utilization and system calls2015Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [en]

    The popularity of mobile games has increased drastically during the recent years andmany people use them as their main source of entertainment. Mobile gamescommunicate with other devices over the network which consumes a lot of energy,especially when connected to cellular networks (e.g., 3G). This high energy expensecan feel unjustified to the player since always-on network connectivity is not requiredin order to play most games.Furthermore, the number of malware-infected applications in offical applicationstores has increased significantly in the recent years. These malware-infectedapplications can gain unrestricted access and control of users phones which can be athreat to security. Information about the behaviour characteristics of games can beused to develop or improve systems for detecting malware applications.In this thesis, 20 popular Android games are analysed with a focus on the datacommunication, CPU utilization and system call behaviour. The main subject of thedata communication study is the 3G communication energy consumed by games. Thesystem call study aims at quantifying the number and type of calls used by games.This may be useful in a further study of harmful behaviour by apps.The profiling results presented in this report show that the communication energyvaries drastically among games. Games with a very similar gameplay can consumevery different amounts of energy which indicates that there is room for improvementsin many of the games. Ad-free games consume significantly less energy than gamesthat use in-app advertisements. The results show that improving the advertisementfetching policy could reduce the energy consumption of these games. The majority ofthe games can be played without network connectivity and therefore thecommunication energy consumed could be completely avoided. The thesis alsoshows that games use a wide variety of system calls and that many of the system callsare common among the games.

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  • 175.
    Almquist, Mathias
    et al.
    Linköping University, Department of Computer and Information Science.
    Almquist, Viktor
    Linköping University, Department of Computer and Information Science.
    Analysis of 360° Video Viewing Behaviours2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In this thesis we study users' viewing motions when watching 360° videos in order to provide information that can be used to optimize future view-dependent streaming protocols. More specifically, we develop an application that plays a sequence of 360° videos on an Oculus Rift Head Mounted Display and records the orientation and rotation velocity of the headset during playback. The application is used during an extensive user study in order to collect more than 21 hours of viewing data which is then analysed to expose viewing patterns, useful for optimizing 360° streaming protocols. 

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  • 176.
    Almquist, Mathias
    et al.
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Almquist, Viktor
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Krishnamoorthi, Vengatanathan
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Carlsson, Niklas
    Linköping University, Department of Computer and Information Science, Database and information techniques. Linköping University, Faculty of Science & Engineering.
    Eager, Derek
    Univ Saskatchewan, Canada.
    The Prefetch Aggressiveness Tradeof in 360 degrees Video Streaming2018In: PROCEEDINGS OF THE 9TH ACM MULTIMEDIA SYSTEMS CONFERENCE (MMSYS18), ASSOC COMPUTING MACHINERY , 2018, p. 258-269Conference paper (Refereed)
    Abstract [en]

    With 360 degrees video, only a limited fraction of the full view is displayed at each point in time. This has prompted the design of streaming delivery techniques that allow alternative playback qualities to be delivered for each candidate viewing direction. However, while prefetching based on the users expected viewing direction is best done close to playback deadlines, large buffers are needed to protect against shortfalls in future available bandwidth. This results in conflicting goals and an important prefetch aggressiveness tradeoff problem regarding how far ahead in time from the current playpoint prefetching should be done. This paper presents the first characterization of this tradeoff. The main contributions include an empirical characterization of head movement behavior based on data from viewing sessions of four different categories of 360 degrees video, an optimization-based comparison of the prefetch aggressiveness tradeoffs seen for these video categories, and a data-driven discussion of further optimizations, which include a novel system design that allows both tradeoff objectives to be targeted simultaneously. By qualitatively and quantitatively analyzing the above tradeoffs, we provide insights into how to best design tomorrows delivery systems for 360 degrees videos, allowing content providers to reduce bandwidth costs and improve users playback experiences.

  • 177.
    Almquist, Mathias
    et al.
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Almquist, Viktor
    Linköping University, Department of Computer and Information Science. Linköping University, Faculty of Science & Engineering.
    Vergara Alonso, Ekhiotz Jon
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Nadjm-Tehrani, Simin
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Communication Energy Overhead of Mobiles Games2015In: MobiGames '15: Proceedings of the 2nd Workshop on Mobile Gaming, Association for Computing Machinery (ACM), 2015, p. 1-6Conference paper (Other academic)
    Abstract [en]

    Although a significant proportion of the mobile apps are games there has been little attention paid to their specific characteristics with respect to communication energy. In this paper we select 20 mobile games among the top 100 free Android games, and study their data patterns and communication energy use over a total of 25 hours of playing. The analysis of the energy for communication over 3G networks indicates that there is a wide variation among the games, the largest footprint being 8 times higher than the lowest one. The results also indicates both app-specific and category-specific relations between data pattern and energy use, as well as variations in CPU utilisation.

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  • 178.
    Almqvist, Joel
    et al.
    Linköping University, Department of Computer and Information Science.
    Detterfelt, Björn
    Linköping University, Department of Computer and Information Science.
    Håkansson, Tim
    Linköping University, Department of Computer and Information Science.
    Kjellström, David
    Linköping University, Department of Computer and Information Science.
    Löjdquist, Axel
    Linköping University, Department of Computer and Information Science.
    Oskarsson, Joel
    Linköping University, Department of Computer and Information Science.
    Wahid, Lieth
    Linköping University, Department of Computer and Information Science.
    Wilkens, Alexander
    Linköping University, Department of Computer and Information Science.
    Realtidsmultiplayerspel på IoT-backend2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This report presents a project carried out for the company Cybercom by eight students from Linköping University. The aim of the project has been to develop a real-time multiplayer game using an existing system for communication between different devices. The game has been developed as a web app that contains multiple game modes. The specific development methodology that has been used throughout the project is presented in this report. This methodology has been iterative, agile and followed a simplified version of the Scrum framework. The end result of the project is a well functioning product that directly creates value for the customer, but also allows for further development.

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  • 179.
    Almqvist, Tom
    Linköping University, Department of Computer and Information Science, Software and Systems.
    Utvärdering av metoder för temporär lagring av data i en webbapplikation2018Independent thesis Basic level (university diploma), 10,5 credits / 16 HE creditsStudent thesis
    Abstract [sv]

    I databasapplikationer är det viktigt att kunna minska belastningen på en databas i syfte att minska responstiden. Detta kan exempelvis åstadkommas med hjälp av olika metoder för temporär lagring av data, något som studerats i detta arbete. De metoder som utvärderats och jämförts i detta arbete är Redis och memcached. Utvärderingen jämförde Redis och memcached med avseende på minnesanvändning, CPU-användning och tidsåtgång för hämtning av data i respektive cache. Dessa egenskaper beräknades med hjälp av verktygen SYSSTAT och valgrind. Det visade sig i slutändan att den interna fragmenteringen i memcached är dess största nackdel, medan Redis är något långsammare än memcached när det gäller att hämta stora mängder data. Utifrån de resultat som anskaffats var det tänkt att använda den metod som är mest lämpad för SysPartners ändamål, vilket ansågs vara Redis.

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  • 180.
    Al-mufti, Summia
    et al.
    Linköping University, Department of Computer and Information Science.
    Jönsson, Rasmus
    Linköping University, Department of Computer and Information Science.
    HTTP/2, Server Push and Branched Video: Evaluation of using HTTP/2 Server Push in Dynamic Adaptive Streaming over HTTP with linear and non-linear prefetching algorithms2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to investigate and test the usage of HTTP/2 in dynamic adaptive video streaming as well as to take a look into how it can be used to benefit prefetching algorithms used with branched video. With a series of experiments the performance gains of using HTTP/2 rather than the older standard HTTP/1.1 has been investigated. The results has shown no significant change to player quality and buffer occupancy when using HTTP/2, though our tests has shown in a slight decrease in overall playback quality when using HTTP/2. When using a linear prefetch of two fragments an average quality improvement of 4.59% has been shown, however, the result is inconclusive due to variations in average quality between different values for how many fragments to prefetch. Average buffer occupancy has shown promise with a maximum increase of 12.58%, when using linear prefetch with three fragments. The values for buffer occupancy gains are conclusive. Two implementations for non-linear prefetching has been made. The first one uses HTTP/2 server push to deliver fragments for prefetching and the second one uses client-side invoked HTTP requests to pull fragments from the server. Using HTTP/2 server push has shown in a decrease of 2.5% in average total load time while using client-side pulling has shown in a decrease of 34% in average total load time.

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    HTTP/2, Server Push and Branched Video
  • 181.
    Alnervik, Erik
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Evaluation of the Configurable Architecture REPLICA with Emulated Shared Memory2014Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    REPLICA is a family of novel scalable chip multiprocessors with configurable emulated shared memory architecture, whose computation model is based on the PRAM (Parallel Random Access Machine) model.

    The purpose of this thesis is to, by benchmarking different types of computation problems on REPLICA, similar parallel architectures (SB-PRAM and XMT) and more diverse ones (Xeon X5660 and Tesla M2050), evaluate how REPLICA is positioned among other existing architectures, both in performance and programming effort. But it should also examine if REPLICA is more suited for any special kinds of computational problems.

    By using some of the well known Berkeley dwarfs, and input from unbiased sources, such as The University of Florida Sparse Matrix Collection and Rodinia benchmark suite, we have made sure that the benchmarks measure relevant computation problems.

    We show that today’s parallel architectures have some performance issues for applications with irregular memory access patterns, which the REPLICA architecture can solve. For example, REPLICA only need to be clocked with a few MHz to match both Xeon X5660 and Tesla M2050 for the irregular memory access benchmark breadth first search. By comparing the efficiency of REPLICA to a CPU (Xeon X5660), we show that it is easier to program REPLICA efficiently than today’s multiprocessors.

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  • 182.
    Alnervik, Jonna
    et al.
    Linköping University, Department of Computer and Information Science, Statistics.
    Nord Andersson, Peter
    Linköping University, Department of Computer and Information Science, Statistics.
    En retrospektiv studie av vilka patientgrupper som erhåller insulinpump2010Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Målsättning

    Att utreda skillnader i tillgänglighet till insulinpump mellan olika patientgrupper samt vad som orsakar ett byte till insulinpump.

    Metod

    Data från 7224 individer med typ 1 diabetes vid tio olika vårdenheter analyserades för att utreda effekterna av njurfunktion, kön, långtidsblodsocker, insulindos, diabetesduration samt ålder. Jämförelsen mellan patientgrupper utfördes med logistisk regression som en tvärsnittsstudie och Cox-regression för att utreda vad som föregått ett byte till pump.

    Resultat

    Genom logistisk regression erhölls en bild av hur skillnader mellan patienter som använder insulinpump och patienter som inte gör det ser ut i dagsläget. Cox-regressionen tar med ett tidsperspektiv och ger på så sätt svar på vad som föregått ett byte till insulinpump. Dessa analyser gav liknande resultat gällande variabler konstanta över tiden. Kvinnor använder pump i större utsträckning än män och andelen pumpanvändare skiljer sig åt vid olika vårdenheter. I dagsläget visar sig hög ålder sänka sannolikheten att använda insulinpump, vilket bekräftas vid den tidsberoende studien som visade hur sannolikheten att byta till pump är avsevärt lägre vid hög ålder. Långtidsblodsockret har också tydlig effekt på sannolikheten att gå över till pump där ett högt långtidsblodsocker medför hög sannolikhet att byta till insulinpump.

    Slutsatser

    I dagsläget finns det skillnader i andelen insulinpumpanvändare mellan olika patientgrupper och skillnader finns även i de olika gruppernas benägenhet att byta från andra insulinbehandlingar till insulinpump. Beroende av patienters njurfunktion, kön, långtidsblodsocker, insulindos, diabetesduration och ålder har dessa olika sannolikheter att byta till insulinpump.

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  • 183.
    Al-Omaishe, Allaa
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering. 860418-9061.
    The impacts of adopting large touch screens and tablets with access  to electronic healthcare records2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the last decade modern information technology systems have been introduced to healthcare in order to improve it. The aim of this study is to present the impact of such information system’s adoption on patient safety and efficiency within healthcare.

    Interviews, observations along with literature study were conducted in order to study the impact of the adoption on patient safety and efficiency at hospital’s wards where a new information system is implemented.

    The conclusion of this study is that such information technology systems can improve patient safety. However it is believed that the information technology system can improve efficiency in some aspects such as the communication among medical care personnel while other aspects within efficiency can be achieved if some improvements are made. Moreover the ability to access Electronic Healthcare Records is considered to be important to improve the medical care, which can increase patient safety. 

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  • 184.
    Alsaadi, Sarah
    et al.
    Linköping University, Department of Computer and Information Science, The Division of Statistics and Machine Learning.
    Wänström, Linda
    Linköping University, Department of Computer and Information Science, The Division of Statistics and Machine Learning.
    Sjögren, Björn
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning.
    Bjärehed, Marlene
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning.
    Thornberg, Robert
    Linköping University, Department of Behavioural Sciences and Learning, Education, Teaching and Learning. Linköping University, Faculty of Educational Sciences.
    Collective moral disengagement and school bullying: An initial validation study of the Swedish scale version2016Conference paper (Refereed)
  • 185.
    Al-Trad, Anas
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Optimized Composition of Parallel Components on a Linux Cluster2012Independent thesis Advanced level (degree of Master (Two Years)), 30 credits / 45 HE creditsStudent thesis
    Abstract [en]

    We develop a novel framework for optimized composition of explicitly parallel software components with different implementation variants given the problem size, data distribution scheme and processor group size on a Linux cluster. We consider two approaches (or two cases of the framework). 

    In the first approach, dispatch tables are built using measurement data obtained offline by executions for some (sample) points in the ranges of the context properties. Inter-/extrapolation is then used to do actual variant-selection for a given execution context at run-time.

    In the second approach, a cost function of each component variant is provided by the component writer for variant-selection. These cost functions can internally lookup measurements' tables built, either offline or at deployment time, for computation- and communication-specific primitives.

    In both approaches, the call to an explicitly parallel software component (with different implementation variants) is made via a dispatcher instead of calling a variant directly.

    As a case study, we apply both approaches on a parallel component for matrix multiplication with multiple implementation variants. We implemented our variants using Message Passing Interface (MPI). The results show the reduction in execution time for the optimally composed applications compared to applications with hard-coded composition. In addition, the results show the comparison of estimated and measured times for each variant using different data distributions, processor group and problem sizes.

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  • 186.
    Alvarsson, Andreas
    Linköping University, Department of Computer and Information Science.
    The development of a sports statistics web application: Sports Analytics and Data Models for a sports data web application2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Sports and technology have always co-operated to bring better and more specific sports statistics. The collection of sports game data as well as the ability to generate valuable sports statistics of it is growing. This thesis investigates the development of a sports statistics application that should be able to collect sports game data, structure the data according to suitable data models and show statistics in a proper way.

    The application was set to be a web application that was developed using modern web technologies. This purpose led to a comparison of different software stack solutions and web frameworks. A theoretical study of sports analytics was also conducted, which gave a foundation for how sports data could be stored and how valuable sports statistics could be generated.

    The resulting design of the prototype for the sports statistics application was evaluated. Interviews with persons working in sports contexts evaluated the prototype to be both user-friendly, functional and fulfilling the purpose to generate valuable statistics during sport games.

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  • 187.
    Alvehus, Johan
    Linköping University, Department of Computer and Information Science. Linköping University, The Institute of Technology.
    Mötets metaforer: en studie av berättelser om möten1999Licentiate thesis, monograph (Other academic)
    Abstract [en]

    Although meetings are, for most, an important part of the daily routine, they are easily disregarded. When viewed as a form of interaction, meetings become more problematic. While the form of interaction is important for the interpretation of content, it also opens up possibilities for manipulation.

    The purpose of this study is to contribute to an increased understanding of the possibilities for constructing the form of interaction in meetings. This has been achieved through a study of narratives on meetings, here in terms of normative management literature.

    The literature on meeting management offers distinct views on how meetings supposedly function. These views can be expressed in terms of two metaphors: meetings as organisms and meetings as machines. Metaphors serve to both highlight and conceal certain aspects of a phenomenon. The organism metaphor highlights the homogeneity and dynamics of meetings. In contrast, the machine metaphor helps explain how meetings work, as well as how they can be measured and evaluated.

    Different metaphors are often portrayed as either totally distinct from, or directly related to each other. However, the literature on managing meetings reveals that the organism and machine metaphors are both related and discrete. Accordingly, the dialectics of highlighting and concealing aspects of a phenomenon must be complemented by the dialectics between the metaphors. The latter can be expressed in terms of links that integrate the metaphors, as well as links that separate the metaphors and define differences between them. In the literature these links emerge as options for action, i.e., alternatives for enacting a particular metaphor using specific techniques. Accordingly, certain techniques provide options for choosing the form of interaction. However, meetings in themselves can also be viewed as a kind of information technology in the same way as e-mail or videoconferencing technology. Normative statements, e.g. the literature on managing meetings, are important clues for the analysis of how different forms of social action can be designed.

    In studying interaction and communication, an analysis of conscious attempts to design or influence situations should be considered. Such analysis is facilitated by working with a refined concept of form-the double dialectics of form/content and form/form-along with the concept of techniques.

  • 188.
    Alvila, Markus
    et al.
    Linköping University, Department of Computer and Information Science.
    Johansson, Jonathan
    Linköping University, Department of Computer and Information Science.
    Johansson, Philip
    Linköping University, Department of Computer and Information Science.
    Lenz, Silas
    Linköping University, Department of Computer and Information Science.
    Lindmark, Sebastian
    Linköping University, Department of Computer and Information Science.
    Norberg, Emil
    Linköping University, Department of Computer and Information Science.
    Regard, Viktor
    Linköping University, Department of Computer and Information Science.
    Övervakning och bedömning av flygledares prestanda2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Möjligheten att fjärrstyra flygledartorn kommer att ställa högre krav på flygledares koncentrations- och simultanförmåga runt om i Sverige. Det är viktigt att åtgärder tas för att förhindra att en trött flygledare begår ett misstag och det är just detta som det framtagna systemet försöker att förhindra.

    Med hjälp av sensorer och modeller kan systemet bestämma flygledarens trötthet, stressnivå, uppmärksamhet och nuvarande arbetsuppgift. Alla värden presenteras i ett enkelt grafiskt gränssnitt. Tillsammans med resultaten för flygledarens hälsa presenteras även all sensordata i gränssnittet.

    Systemet är främst uppbyggt av två olika ramverk: Apache NiFi och Apache Spark. Vad de båda ramverken har gemensamt är att de har funktionalitet för att bygga kluster, vilket betyder att endast antalet noder sätter gränsen för hur många flygledare som kan vara uppkopplade samtidigt.

    Denna prototyp har inte all funktionalitet på plats för att behandla flera flygledare. Grunden är däremot lagd för att enkelt kunna implementera ytterligare funktionalitet och i slutändan ha flera flygledare uppkopplade samtidigt. Systemet öppnar upp möjligheter till att fördela arbetet på de flygledare som är mest fokuserade och kan därför bidra till att öka flygsäkerheten.

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  • 189.
    Alvinge, Björn
    Linköping University, Department of Computer and Information Science.
    Is Speed a Magnitude?: Neurocognitive Estimations of Speed and its’ Connection to Time, Space and Numeric/Quantity Estimations2018Independent thesis Basic level (degree of Bachelor), 12 credits / 18 HE creditsStudent thesis
    Abstract [en]

    Associations between space, time, numbers and quantities have suggested that there must be a shared representational format which underlies them. One of the more prominent theories of an underlying system of representation is that of ATOM, which suggests that the there exists a generalized system of magnitude which processes these dimensions. However, there has been no study that examines whether speed is also processed within such a system. This study investigates this by seeing if a SNARC or Problem-Size effect arise in two speed estimation tests. The fundamental task for the participants in both tests was to judge which of two stimuli was the fastest, with the stimuli moving towards a wall located in the center of a computer screen. Their correct discrimination and response time was recorded. The results found that there were no significant results for either effect. This might be due to low sample size, methodological difficulties, and low robustness. Future research might amend these difficulties by having a more consistent setup with more trials reflecting the effect being tested and fix some potential problems with the test environment.

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  • 190.
    Amanda, Jaber
    Linköping University, Department of Computer and Information Science.
    Evaluating the Team Resilience Assessment Method for Simulation (TRAMS)2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The Team Resilience Assessment Method for Simulation (TRAMS) is an instrument that consist of several measurements, such as team-member exchange, workload, the TRAMS observation protocol etc. This thesis researches the observation protocol. The TRAMS protocol is an assessment method for resilience in simulation games. The aim of this protocol is to support the identification of resilience strategies used and developed by the participants in a simulation game. It is a challenge to assess resilience in teams and that is why the TRAMS protocol has been developed. The scenario of the simulation games is a disruption for 10 days in the card payment system. During the simulation games, the participants work in teams and have to try to cope with the disruption in the card payment system. During the course of this study, 14 simulation games have been conducted with seven different teams. Each of the simulation games has been executed during one whole day, and the participating teams have in total played two games each. During every simulation game there were three observers equipped with the TRAMS protocol. To interpret the data collected with the TRAMS protocol, two methods have been used: transcription and thematic analysis. As a result, guidelines and design changes was formed. In addition, results showed that the distribution and frequency of observations of resilience strategies made were similar, that the observations noted by the observers were similar, and lastly eight themes from the data collection could be extracted: Coordinate and collaborate, Payment options, Cash circulation, Safety, Fuel and transportation, Inform, communicate and the media, Hoarding and rationing, Vulnerable groups. In conclusion, the TRAMS protocol is still under development and 15 more simulation games are planned to be conducted within the ongoing CCRAAAFFTING project. However, the protocol has been applied in this study´s 14 simulation games so far, and the similarities in how the observers filled in the protocol and how similar the observations were, indicate that it hopefully can develop into a recognized research tool in the future. 

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  • 191.
    Amaral, Vasco
    et al.
    Univ Nova Lisboa, Portugal.
    Norberto, Beatriz
    Univ Nova Lisboa, Portugal.
    Goulao, Miguel
    Univ Nova Lisboa, Portugal.
    Aldinucci, Marco
    Univ Torino, Italy.
    Benkner, Siegfried
    Univ Vienna, Austria.
    Bracciali, Andrea
    Univ Stirling, Scotland.
    Carreira, Paulo
    Univ Lisbon, Portugal.
    Celms, Edgars
    Univ Latvia, Latvia.
    Correia, Luis
    Univ Lisbon, Portugal.
    Grelck, Clemens
    Univ Amsterdam, Netherlands.
    Karatza, Helen
    Aristotle Univ Thessaloniki, Greece.
    Kessler, Christoph
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Kilpatrick, Peter
    Queens Univ Belfast, North Ireland.
    Martiniano, Hugo
    Univ Lisbon, Portugal.
    Mavridis, Ilias
    Aristotle Univ Thessaloniki, Greece.
    Pllana, Sabri
    Linnaeus Univ, Sweden.
    Respicio, Ana
    Univ Lisbon, Portugal.
    Simao, Jose
    Inst Politecn Lisboa, Portugal.
    Veiga, Luis
    Univ Lisbon, Portugal.
    Visa, Ari
    Tampere Univ, Finland.
    Programming languages for data-Intensive HPC applications: A systematic mapping study2020In: Parallel Computing, ISSN 0167-8191, E-ISSN 1872-7336, Vol. 91, article id UNSP 102584Article in journal (Refereed)
    Abstract [en]

    A major challenge in modelling and simulation is the need to combine expertise in both software technologies and a given scientific domain. When High-Performance Computing (HPC) is required to solve a scientific problem, software development becomes a problematic issue. Considering the complexity of the software for HPC, it is useful to identify programming languages that can be used to alleviate this issue. Because the existing literature on the topic of HPC is very dispersed, we performed a Systematic Mapping Study (SMS) in the context of the European COST Action cHiPSet. This literature study maps characteristics of various programming languages for data-intensive HPC applications, including category, typical user profiles, effectiveness, and type of articles. We organised the SMS in two phases. In the first phase, relevant articles are identified employing an automated keyword-based search in eight digital libraries. This lead to an initial sample of 420 papers, which was then narrowed down in a second phase by human inspection of article abstracts, titles and keywords to 152 relevant articles published in the period 2006-2018. The analysis of these articles enabled us to identify 26 programming languages referred to in 33 of relevant articles. We compared the outcome of the mapping study with results of our questionnaire-based survey that involved 57 HPC experts. The mapping study and the survey revealed that the desired features of programming languages for data-intensive HPC applications are portability, performance and usability. Furthermore, we observed that the majority of the programming languages used in the context of data-intensive HPC applications are text-based general-purpose programming languages. Typically these have a steep learning curve, which makes them difficult to adopt. We believe that the outcome of this study will inspire future research and development in programming languages for data-intensive HPC applications. (C) 2019 Elsevier B.V. All rights reserved.

  • 192.
    Amdahl, Per
    et al.
    Linköping University, Department of Computer and Information Science.
    Chaikiat, Per
    Linköping University, Department of Computer and Information Science.
    Personas as Drivers: - an alternative approach for creating scenarios for ADAS evaluation2007Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

    Research and development on vehicle safety has lately started to direct its focus towards how to actively support the driver and make it easier for her to drive safely through letting Advanced Driver Assistance Systems (ADAS) have effect on how the driver interacts with the vehicle and the surrounding traffic. This requires research on both how the driver and vehicle perform in different situations, in terms of psychology, cognition and individual differences. In addition, physical limitations and requirements of the driver and the vehicle must be taken into account. Therefore scenarios for evaluation of these systems are required. In the area of user-centered design a rather new method, Personas, is being adopted. This thesis tries to explore if the Persona method is a viable tool for creating scenarios for such evaluations. Experiences after completing this work imply that personas indeed is a viable way to include aspects and raise issues concerning individual variability and situational context in ADAS scenarios.

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    FULLTEXT01
  • 193.
    Ameur, Safia
    Linköping University, Department of Computer and Information Science.
    Picturing Words and Spelling out Pictures Semantic, phonological and spatial aspects of working memory capacity and processing and their implication for information layout2004Independent thesis Advanced level (degree of Magister)Student thesis
    Abstract [en]

    This study investigates verbal and visuospatial memory strategies used by individuals with perceptual or cognitive disabilities. The groups concentrated on in this study are deaf individuals who are native sign language users and individuals with dyslexia.

    The study comprises an experiment and an in-depth study in which a pre-test and a questionnaire were used. Nine deaf signers, two persons with dyslexia and 12 persons without any perceptual or cognitive constraints participated. Of these 23 persons, seven were selected to take part in the in-depth study.

    The results indicate individual differences in working memory capacity among the subjects and differences in performance and processing between native sign language users and hearing individuals. Further, all of the participants were using a number of different strategies and shifting between strategies in the experiment. The results demonstrate that the amount of information individuals are able to hold activated in working memory is dependent on a range of factors, both internal factors specific to the individual and external factors relating to how information is presented. Guidelines for information presentation to limit working memory demands based on the findings are suggested.

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  • 194. Order onlineBuy this publication >>
    Aminifar, Amir
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Analysis, Design, and Optimization of Embedded Control Systems2016Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Today, many embedded or cyber-physical systems, e.g., in the automotive domain, comprise several control applications, sharing the same platform. It is well known that such resource sharing leads to complex temporal behaviors that degrades the quality of control, and more importantly, may even jeopardize stability in the worst case, if not properly taken into account.

    In this thesis, we consider embedded control or cyber-physical systems, where several control applications share the same processing unit. The focus is on the control-scheduling co-design problem, where the controller and scheduling parameters are jointly optimized. The fundamental difference between control applications and traditional embedded applications motivates the need for novel methodologies for the design and optimization of embedded control systems. This thesis is one more step towards correct design and optimization of embedded control systems.

    Offline and online methodologies for embedded control systems are covered in this thesis. The importance of considering both the expected control performance and stability is discussed and a control-scheduling co-design methodology is proposed to optimize control performance while guaranteeing stability. Orthogonal to this, bandwidth-efficient stabilizing control servers are proposed, which support compositionality, isolation, and resource-efficiency in design and co-design. Finally, we extend the scope of the proposed approach to non-periodic control schemes and address the challenges in sharing the platform with self-triggered controllers. In addition to offline methodologies, a novel online scheduling policy to stabilize control applications is proposed.

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  • 195.
    Aminifar, Amir
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Self-Triggered Controllers, Resource Sharing, and Hard Guarantees2016In: 2016 2ND INTERNATIONAL CONFERENCE ON EVENT-BASED CONTROL, COMMUNICATION, AND SIGNAL PROCESSING (EBCCSP), IEEE , 2016Conference paper (Refereed)
    Abstract [en]

    Today, many control applications in embedded and cyber-physical systems are implemented on shared platforms, alongside other hard real-time or safety-critical applications. Having the resource shared among several applications, to provide hard guarantees, it is required to identify the amount of resource needed for each application. This is rather straightforward when the platform is shared among periodic control and periodic real-time applications. In the case of event-triggered and self-triggered controllers, however, the execution patterns and, in turn, the resource usage are not clear. Therefore, a major implementation challenge, when the platform is shared with self-triggered controllers, is to provide hard and efficient stability and schedulability guarantees for other applications. In this paper, we identify certain execution patterns for self-triggered controllers, using which we are able to provide hard and efficient stability guarantees for periodic control applications.

  • 196.
    Aminifar, Amir
    et al.
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Bini, Enrico
    Scuola Super Sant Anna, Italy.
    Eles, Petru lon
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Peng, Zebo
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Analysis and Design of Real-Time Servers for Control Applications2016In: I.E.E.E. transactions on computers (Print), ISSN 0018-9340, E-ISSN 1557-9956, Vol. 65, no 3, p. 834-846Article in journal (Refereed)
    Abstract [en]

    Today, a considerable portion of embedded systems, e.g., automotive and avionic, comprise several control applications. Guaranteeing the stability of these control applications in embedded systems, or cyber-physical systems, is perhaps the most fundamental requirement while implementing such applications. This is different from the classical hard real-time systems where often the acceptance criterion is meeting the deadline. In other words, in the case of control applications, guaranteeing stability is considered to be a main design goal, which is linked to the amount of delay and jitter a control application can tolerate before instability. This advocates the need for new design and analysis techniques for embedded real-time systems running control applications. In this paper, the analysis and design of such systems considering a server-based resource reservation mechanism are addressed. The benefits of employing servers are manifold: providing a compositional and scalable framework, protection against other tasks misbehaviors, and systematic bandwidth assignment and co-design. We propose a methodology for designing bandwidth-optimal servers to stabilize control tasks. The pessimism involved in the proposed methodology is both discussed theoretically and evaluated experimentally.

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  • 197.
    Aminifar, Amir
    et al.
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Bini, Enrico
    Lund University, Sweden.
    Eles, Petru
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Peng, Zebo
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Bandwidth-Efficient Controller-Server Co-Design with Stability Guarantees2014In: Design, Automation & Test in Europe, DATE 2014, IEEE Computer Society, 2014Conference paper (Refereed)
    Abstract [en]

    Many cyber-physical systems comprise several control applications implemented on a shared platform, for which stability is a fundamental requirement. This is as opposed to the classical hard real-time systems where often the criterion is meeting the deadline. However, the stability of control applications depends on not only the delay experienced, but also the jitter. Therefore, the notion of deadline is considered to be artificial for control applications that promotes the need for new techniques for designing cyber-physical systems. The approach in this paper is built on a server-based resource reservation mechanism, which provides compositionality, isolation, and the opportunity of systematic controller--server co-design. We address the controller--server co-design of such systems to obtain design solutions with the minimal bandwidth to guarantee stability.

  • 198.
    Aminifar, Amir
    et al.
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Bini, Enrico
    Lund University, Sweden.
    Eles, Petru
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Peng, Zebo
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Designing Bandwidth-Efficient Stabilizing Control Servers2013In: IEEE Real-Time Systems Symposium, RTSS 2013, IEEE , 2013, p. 298-307Conference paper (Refereed)
    Abstract [en]

    Guaranteeing stability of control applications in embedded systems, or cyber-physical systems, is perhaps the alpha and omega of implementing such applications. However, as opposed to the classical real-time systems where often the acceptance criterion is meeting the deadline, control applications do not primarily enforce hard deadlines. In the case of control applications, stability is considered to be the main design criterion and can be expressed in terms of the amount of delay and jitter a control application can tolerate before instability. Therefore, new design and analysis techniques are required for embedded control systems. In this paper, the analysis and design of such systems considering server-based resource reservation mechanism are addressed. The benefits of employing servers are manifold: (1) providing a compositional framework, (2) protection against other tasks misbehaviors, and (3) systematic bandwidth assignment. We propose a methodology for designing bandwidth-efficient servers to stabilize control tasks.

  • 199.
    Aminifar, Amir
    et al.
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Eles, Petru
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory.
    Peng, Zebo
    Linköping University, Department of Computer and Information Science, ESLAB - Embedded Systems Laboratory. Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, The Institute of Technology.
    Jfair: A Scheduling Algorithm to Stabilize Control Applications2015In: 21st IEEE Real-Time and Embedded Technology and Applications Symposium, Cyber-Physical Systems Week, Seattle, WA, April 2015, IEEE Computer Society, 2015, p. 63-72Conference paper (Refereed)
    Abstract [en]

    Control applications are considered to be among the core applications in cyber-physical and embedded realtime systems, for which jitter is typically an important factor. This paper investigates whether it is possible to guarantee certain amount of jitter for a given set of applications on a shared platform. The effect of jitter on the stability of control applications and its relation with the latency will be discussed. The importance arises from the fact that it is considerably easier to manage the constant part of the delay (known as latency), while the process of coping with the varying part of the delay (known as jitter) is more involved. The proposed solution guarantees certain jitter limits, and at the same time does not lead to overly pessimistic latency values. The results are later used in a design optimization problem to minimize the resource utilized.

  • 200.
    Aminifar, Amir
    et al.
    Embedded Systems Laboratory, École Polytechnique Fédérale de Lausanne (EPFL), Switzerland.
    Eles, Petru
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Peng, Zebo
    Linköping University, Department of Computer and Information Science, Software and Systems. Linköping University, Faculty of Science & Engineering.
    Optimization of Message Encryption for Real-Time Applications in Embedded Systems2018In: IEEE Transactions on Computers, ISSN 0018-9340, Vol. 67, no 5, p. 748-754Article in journal (Refereed)
    Abstract [en]

    Today, security can no longer be treated as a secondary issue in embedded and cyber-physical systems. Therefore, one of the main challenges in these domains is the design of secure embedded systems under stringent resource constraints and real-time requirements. However, there exists an inherent trade-off between the security protection provided and the amount of resources allocated for this purpose. That is, the more the amount of resources used for security, the higher the security, but the fewer the number of applications which can be run on the platform and meet their timing requirements. This trade-off is of high importance since embedded systems are often highly resource constrained. In this paper, we propose an efficient solution to maximize confidentiality, while also guaranteeing the timing requirements of real-time applications on shared platforms.

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