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  • 301.
    Hagelbäck, Johan
    et al.
    Blekinge Institute of Technology, Sweden.
    Johansson, Stefan J.
    Blekinge Institute of Technology, Sweden.
    The Rise of Potential Fields in Real Time Strategy bots2008In: Artificial Intelligence and Interactive Digital Entertainment (AIIDE), Stanford, Stanford University , 2008Conference paper (Refereed)
    Abstract [en]

    Bots for Real Time Strategy (RTS) games are challenging to implement. A bot controls a number of units that may have to navigate in a partially unknown environment, while at the same time search for enemies and coordinate attacks to fight them down. Potential fields is a technique originating from the area of robotics where it is used in controlling the navigation of robots in dynamic environments. We show that the use of potential fields for implementing a bot for a real time strategy game gives us a very competitive, configurable, and non-conventional solution.

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  • 302.
    Hagelbäck, Johan
    et al.
    Blekinge Institute of Technology, Sweden.
    Johansson, Stefan J.
    Blekinge Institute of Technology, Sweden.
    Using Multi-Agent Potential Fields in Real-Time Strategy Games2008In: Seventh International Conference on Autonomous Agents and Multi-agent Systems (AAMAS), 12-16, 2008, Estoril, 2008, p. 631-638Conference paper (Refereed)
    Abstract [en]

    Bots for Real Time Strategy (RTS) games provide a rich challenge to implement. A bot controls a number of units that may have to navigate in a partially unknown environment, while at the same time search for enemies and coordinate attacks to fight them down. Potential fields is a technique originating from the area of robotics where it is used in controlling the navigation of robots in dynamic environments. Although attempts have been made to transfer thetechnology to the gaming sector, assumed problems with efficiency and high costs for implementation have made the industry reluctant to adopt it. We present a Multi-agent Potential Field based bot architecture that is evaluated in a real time strategy game setting and compare it, both in terms of performance, and in terms of softer attributes such as configurability with other state-of-the-art solutions. Although our solution did not reach the performance standards of traditional RTS bots in the test, we see great unexploited benefits inusing multi-agent potential field based solutions in RTS games.

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  • 303.
    Hagelbäck, Johan
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Liapota, Pavlo
    Softwerk, Sweden.
    Lincke, Alisa
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Löwe, Welf
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    The performance of some machine learning approaches in human movement assessment2019In: 13th Multi Conference on Computer Science and Information Systems (MCCSIS) / [ed] Mário Macedo, L. Rodrigues, Porto, Portugal: IADIS Press, 2019, p. 35-42Conference paper (Refereed)
    Abstract [en]

    The advent of commodity 3D sensor technology enabled, amongst other things, the efficient and effective assessment of human movements. Statistical and machine learning approaches map recorded movement instances to expert scores to train models for the automated assessment of new movements. However, there are many variations in selecting the approaches and setting the parameters for achieving high performance, i.e., high accuracy and low response time. The present paper researches the design space and the impact of approaches of statistical and machine learning on accuracy and response time in human movement assessment. Results show that a random forest regression approach outperforms linear regression, support vector regression and neuronal network approaches. Since the results do not rely on the movement specifics, they can help improving the performance of automated human movement assessment, in general.

  • 304.
    Hagelbäck, Johan
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Liapota, Pavlo
    Softwerk, Sweden.
    Lincke, Alisa
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Löwe, Welf
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Variants of Dynamic Time Warping and their Performance in Human Movement Assessment2019In: 21st International Conference on Artificial Intelligence (ICAI'19: July 29 - August 1, 2019, Las Vegas, USA), CSREA Press, 2019, p. 9-15Conference paper (Refereed)
    Abstract [en]

    The advent of commodity 3D sensor technology enabled, amongst other things, the efficient and effective assessment of human movements. Statistical and machine learning approaches map recorded movement instances to expert scores to train models for the automated assessment of new movements. However, there are many variations in selecting the approaches and setting the parameters for achieving good performance, i.e., high scoring accuracy and low response time. The present paper researches the design space and the impact of sequence alignment on accuracy and response time. More specifically, we introduce variants of Dynamic Time Warping (DTW) for aligning the phases of slow and fast movement instances and assess their effect on the scoring accuracy and response time. Results show that an automated stripping of leading and trailing frames not belonging to the movement (using one DTW variant) followed by an alignment of selected frames in the movements (based on another DTW variant) outperforms the original DTW and other suggested variants thereof. Since these results are independent of the selected learning approach and do not rely on the movement specifics, the results can help improving the performance of automated human movement assessment, in general.

  • 305.
    Hagelbäck, Johan
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Lincke, Alisa
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Löwe, Welf
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Rall, Eduard
    AIMO, Sweden.
    On the Agreement of Commodity 3D Cameras2019In: Proceedings of the 2019 International Conference on Image Processing, Computer Vision, & Pattern Recognition / [ed] Hamid R. Arabnia, Leonidas Deligiannidis, Fernando G. Tinetti, CSREA Press, 2019, p. 36-42Conference paper (Refereed)
    Abstract [en]

    The advent of commodity 3D sensor technol- ogy has, amongst other things, enabled the efficient and effective assessment of human movements. Machine learning approaches do not rely manual definitions of gold standards for each new movement. However, to train models for the automated assessments of a new movement they still need a lot of data that map recorded movements to expert judg- ments. As camera technology changes, this training needs to be repeated if a new camera does not agree with the old one. The present paper presents an inexpensive method to check the agreement of cameras, which, in turn, would allow for a safe reuse of trained models regardless of the cameras. We apply the method to the Kinect, Astra Mini, and Real Sense cameras. The results show that these cameras do not agree and that the models cannot be reused without an unacceptable decay in accuracy. However, the suggested method works independent of movements and cameras and could potentially save effort when integrating new cameras in an existing assessment environment.

  • 306. Hagen, Hans
    et al.
    Kerren, Andreas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Computer Science.
    Dannenmann, Peter
    Visualization of Large and Unstructured Data Sets2006Book (Other (popular science, discussion, etc.))
  • 307.
    Hall, Johan
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Transition-Based Natural Language Parsing with Dependency and Constituency Representations2008Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Hall, Johan, 2008. Transition-Based Natural Language Parsing with Dependency and Constituency Representations, Acta Wexionensia No 152/2008. ISSN: 1404-4307, ISBN: 978-91-7636-625-7. Written in English.

    This thesis investigates different aspects of transition-based syntactic parsing of natural language text, where we view syntactic parsing as the process of mapping sentences in unrestricted text to their syntactic representations. Our parsing approach is data-driven, which means that it relies on machine learning from annotated linguistic corpora. Our parsing approach is also dependency-based, which means that the parsing process builds a dependency graph for each sentence consisting of lexical nodes linked by binary relations called dependencies. However, the output of the parsing process is not restricted to dependency-based representations, and the thesis presents a new method for encoding phrase structure representations as dependency representations that enable an inverse transformation without loss of information. The thesis is based on five papers, where three papers explore different ways of using machine learning to guide a transition-based dependency parser and two papers investigate the method for dependency-based phrase structure parsing.

    The first paper presents our first large-scale empirical study of parsing a natural language (in this case Swedish) with labeled dependency representations using a transition-based deterministic parsing algorithm, where the dependency graph for each sentence is constructed by a sequence of transitions and memory-based learning (MBL) is used to predict the transition sequence. The second paper further investigates how machine learning can be used for guiding a transition-based dependency parser. The empirical study compares two machine learning methods with five feature models for three languages (Chinese, English and Swedish), and the study shows that support vector machines (SVM) with lexicalized feature models are better suited than MBL for guiding a transition-based dependency parser. The third paper summarizes our experience of optimizing and tuning MaltParser, our implementation of transition-based parsing, for a wide range of languages. MaltParser has been applied to over twenty languages and was one of the top-performing systems in the CoNLL shared tasks of 2006 and 2007.

    The fourth paper is our first investigation of dependency-based phrase structure parsing with competitive results for parsing German. The fifth paper presents an improved encoding method for transforming phrase structure representations into dependency graphs and back. With this method it is possible to parse continuous and discontinuous phrase structure extended with grammatical functions.

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  • 308.
    Hall, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datavetenskap.
    Nilsson, Jens
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datavetenskap.
    Nivre, Joakim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datavetenskap.
    Eryigit, Gülsen
    Megyesi, Béata
    Nilsson, Mattias
    Saers, Markus
    Single Malt or Blended? A Study in Multilingual Parser Optimization2007In: Proceedings of the CoNLL Shared Task Session of EMNLP-CoNLL 2007, Association for Computational Linguistics , 2007, p. 933–939-Conference paper (Refereed)
    Abstract [en]

    We describe a two-stage optimization of the MaltParser system for the ten languages in the multilingual track of the CoNLL 2007 shared task on dependency parsing. The first stage consists in tuning a single-parser system for each language by optimizing parameters of the parsing algorithm, the feature model, and the learning algorithm. The second stage consists in building an ensemble system that combines six different parsing strategies, extrapolating from the optimal parameters settings for each language. When evaluated on the official test sets, the ensemble system significantly outperforms the single-parser system and achieves the highest average labeled attachment score.

  • 309.
    Hall, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datalogi.
    Nivre, Joakim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datalogi.
    A Dependency-Driven Parser for German Dependency and Constituency Representations2008In: Proceedings of the ACL-08: HLT Workshop on Parsing German (PaGe-08), Association for Computational Linguistics (ACL),Stroudsburg , 2008, p. 47-54Conference paper (Refereed)
    Abstract [en]

    We present a dependency-driven parser that parses both dependency structures and constituent structures. Constituency representations are automatically transformed into dependency representations with complex arc labels, which makes it possible to recover the constituent structure with both constituent labels and grammatical functions. We report a labeled attachment score close to 90% for dependency versions of the TIGER and TüBa-D/Z treebanks. Moreover, the parser is able to recover both constituent labels and grammatical functions with an F-Score over 75% for TüBa-D/Z and over 65% for TIGER.

  • 310.
    Hall, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Nivre, Joakim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    A generic architecture for data-driven dependency parsing2005In: Proceedings of the 15th Nordic Conference of Computational Linguistics (NODALIDA), University of Joensuu electronic publications in linguistics and language technology, Joensuu , 2005, p. 47-56Conference paper (Refereed)
    Abstract [en]

    We present a software architecture for data-driven dependency parsing of unrestricted natural language text, which achieves a strict modularization of parsing algorithm, feature model and learning method such that these parameters can be varied independently. The design has been realized in MaltParser, which supports several parsing algorithms and learning methods, for which complex feature models can be defined in a special description language.

  • 311.
    Hall, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Nivre, Joakim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Parsing Discontinuous Phrase Structure with Grammatical Functions2008In: Advances in Natural Language Processing, Springer Berlin / Heidelberg , 2008, p. 169-180Conference paper (Refereed)
    Abstract [en]

    This paper presents a novel technique for parsing discontinuous phrase structure representations, labeled with both phrase labels and grammatical functions. Phrase structure representations are transformed into dependency representations with complex edge labels, which makes it possible to induce a dependency parser model that recovers the phrase structure with both phrase labels and grammatical functions. We perform an evaluation on the German TIGER treebank and the Swedish Talbanken05 treebank and report competitive results for both data sets.

  • 312.
    Hall, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datavetenskap.
    Nivre, Joakim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datavetenskap.
    Nilsson, Jens
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datavetenskap.
    A Hybrid Constituency-Dependency Parser for Swedish2007In: Proceedings of the 16th Nordic Conference of Computational Linguistics (NODALIDA), 2007, p. 284–287-Conference paper (Refereed)
    Abstract [en]

    We present a data-driven parser that derives both constituent structures and dependency structures, alone or in combination, in one

    and the same process. When trained and tested on data from the Swedish treebank Talbanken05, the parser achieves a labeled dependency accuracy of 82% and a labeled bracketing F-score of 75%.

  • 313.
    Hall, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datalogi.
    Nivre, Joakim
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datalogi.
    Nilsson, Jens
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Datalogi.
    Discriminative Classifiers for Deterministic Dependency Parsing2006In: Proceedings of the 44rd Annual Meeting of the Association for Computational Linguistics and 21th International Conference on Computational Linguistics (COLING-ACL 2006), July 17-21, 2006, Sydney, Australia, Association for Computational Linguistics, Stroudsburg , 2006, p. 316-323Conference paper (Refereed)
    Abstract [en]

    Deterministic parsing guided by treebankinduced classifiers has emerged as a simple and efficient alternative to more complex models for data-driven parsing. We present a systematic comparison of memory-based learning (MBL) and support vector machines (SVM) for inducing classifiers for deterministic dependency parsing, using data from Chinese, English and Swedish, together with a variety of different feature models. The comparison shows that SVM gives higher accuracy for richly articulated feature models across all languages, albeit with considerably longer training times. The results also confirm that classifier-based deterministic parsing can achieve parsing accuracy very close to the best results reported for more complex parsing models.

  • 314.
    Hallqvist, Carina
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering. Informatik.
    Designing Democracy: Mobilen i demokratins tjänst – ur ett designperspektiv2006Licentiate thesis, monograph (Other academic)
    Abstract [sv]

    Avhandlingen tar sin utgångspunkt i det av Vinnova finansierade projektet »Mobilen i demokratins tjänst» även kallat [demos], vilket drevs av Interactive Institutes Studio[12-21] under perioden 2002 – 2004. De nya mediernas växande betydelse för ungdomars vardagsliv var en viktig faktor bakom [demos]-projektet. Persondatorer, mobiltelefoner, digitala kameror, MP3-spelare och andra digitala verktyg är idag självklara för de flesta ungdomar i västvärlden. Dessa verktyg, liksom Internets mångfald, har snabbt blivit en given del av såväl deras skolarbete som deras fritid. Detta har fått effekt på ungdomars sätt att leka, kommunicera, arbeta och skapa sociala gemenskaper. Ungdomars självklara förhållningssätt till digitala media gör att de ofta utvecklar oväntade och innovativa användningsområden för tjänster och verktyg, genom vad som skulle kunna kallas ett kreativt »missbruk».

    I [demos]-projektet var ambitionen att i arbetet med morgondagens vuxna relatera frågor kring teknik- och konceptutveckling till frågor som har med vårt samhälle och nya former för demokrati att göra. Den övergripande målsättningen i projektet var att undersöka vad som händer om man använder mobila tjänster som ett hjälpmedel och en utmaning i skoldemokratin.

    En prototyp baserad på sms-tekniken utvecklades och testades inom projektets ram. Prototypen utvecklades utifrån två huvudspår, dels representantens behov att undersöka mandat i medlemsgruppen och dels de enskilda medlemmarnas behov att påkalla ledarna och övriga medlemmars uppmärksamhet och skapa opinion kring en viss fråga.

    I avhandlingen presenteras en fallstudiebeskrivning av [demos]-projektet. Avsikten med denna är att tillföra området en beskrivning av och reflektioner kring ett praktiskt exempel på en implementation där man haft avsikten att använda sig av vardagsteknik i form av sms för att stödja demokratiska processer. Avhandlingen belyser och diskuterar former för användarmedverkan i spontan design. I fokus är området digitala media och viljan till medskapande som understöds av den interaktiva potentialen i digitala verktyg och medier. Dessa ger möjligheter att själv eller tillsammans med andra skapa nya sociala sammanhang, filmer, bilder, musik.

    Ytterligare ett viktigt led i beskrivningen och analysen av projektet har varit att undersöka de tekniska och organisatoriska dimensioner vilka ligger till grund för projektets resultat. Särskilt studerades hur man genom att utgå från nyttjandet av sms som en »vardaglig teknik» kan utforma ett system som ett stöd för demokratiska processer. Den fråga som behandlas här är vad som händer då vi tillför de efterfrågade tekniska möjligheterna. Ökar engagemanget att delta i demokratiska processer då deltagarna själva fått välja redskap/teknik? Blir designprocessen mera demokratisk?

    Slutligen diskuteras den övergripande problematik som ligger i att bedriva forskning och praktik parallellt.

  • 315.
    Hamberg, Christer
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    GUI driven End to End Regression testing with Selenium2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Digitalization has changed our world and how we interact with different systems. Desktop applications have more and more been integrated with internet, and the web browser has become the Graphical User Interface (GUI) in today’s system solutions. A change that needs to be considered in the automated regression testing process. Using the actual GUI has over time shown to be a complicated task and is therefore often broken out as its own standalone test object. This study looked into time and quality constrains of using the GUI as driver of the regression testing of business requirements in a web based solution. By evaluating the differences in execution times of test cases between Application Programming Interface (API) calls and GUI driven testing, flakiness of test results and required modifications over time for a specific test suite. These constraints were analyzed by looking into how reliability of the test results could be achieved. With a GUI driven full end to end scope the quality in software solutions could be improved with a reduction in the number of interface issues and detected errors in deployed systems. It would also reduce the volume of test cases that needs to be executed and maintained as there are no longer standalone parts to verify separately with partially overlapping test cases. The implementation utilized Selenium WebDriver to drive the GUI and the results showed that by utilizing Selenium the test execution times were increased from approximately 2 seconds (API) to 20-75 seconds (Selenium). The flaky test results could be eliminated by applying the appropriate pattern to detect, locate, and scroll into visibility prior to interacting with the elements. In the end of the study the test execution results were 100% reliable. The navigation required 15 modifications over time to keep them running. By applying the appropriate pattern a reliable test result can be achieved in end to end regression testing where the test case is driven from the GUI, however with an increase in execution time.

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  • 316.
    Hamidi, Ali
    et al.
    Linnaeus University, Faculty of Technology, Department of Informatics.
    Milrad, Marcelo
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Increasing STEM engagement through the mediation of textile materials combined with physical computing2019In: Transforming lLearning with meaningful technologies: 14th European Conference on Technology Enhanced Learning, EC-TEL 2019, Delft, The Netherlands, September 16–19, 2019, Proceedings / [ed] Maren Scheffel, Julien Broisin, Viktoria Pammer-Schindler, Andri Ioannou & Jan Schneider, Springer, 2019, Vol. 11722, p. 617-621Conference paper (Refereed)
    Abstract [en]

    Recent trends indicate an increasing global demand for skilled IT and Engineering professionals. At the same, it has been acknowledged that there is a decline in the number of graduates in the disciplines of Science, Technology, Engineering and Mathematics (STEM). The lack of interest in these subjects, which has been addressed by many scholars, has triggered recent efforts in order to investigate novel ways to attract and engage more young students in STEM related subjects. In this paper, we describe an exploratory qualitative research study that has been carried out by combining the subjects of technology and programming in a series of workshops hosting sixty pupils 12–13 years old. Children have used the Makey-Makey kit and the Scratch programming language together with textiles to explore how the combination of these different forms of expression can influence their engagement and interest with STEM related topics. The theoretical ideas used for the design and implementation of this study were guided by flow theory. Data was collected through observations, video recordings, and semi-structured interviews. The initial results of this study indicate that the attributes of attention, motivation, and empowerment shape the levels of engagement to retain and reinforce the flow state by using all these materials.

  • 317.
    Hansson, Rickard
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Lindau, Emil
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Parallell utveckling av en- och flerspelarläge i spel: En strävan efter separation2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This paper addresses the question formulation “How does one aid a parallel development of singleplayer and multiplayer in game development?” The reasoning behind is that we believe a separation between the two achieves a greater agility in software development minded towards games. Something that the industry and developers alike historically have struggled and had problems with. At the same time a separation of functionality divides the different areas of expertise (game logic and network) so that the right person can focus on the right thing in a development cycle. The contribution to the scarce research in the general area computer science more narrowly and specific, game development research is mainly to pave the way for further research. The problem has been tackled through Action Research, meaning the use of practical development iterated towards a potential solution, and on a weekly basis considered the solution and made improvements and adjustments on it. This paper describes a solution in form of a software design and a couple of rules to relate to as well as the experience we obtained throughout this project.

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  • 318.
    Harnell, Jonas
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Alemayehn, Yonatan
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    En jämförande studie av IPv4 och IPv62005Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The Internet protocol of today has been used for over 20 years. A new version of the protocol has been developed to replace the old one. This is a direct result due to the explosive growth of the usage of the Internet. This follows by new demands which needs new solutions. This report brings up the old protocol IPv4, the new protocol IPv6 and shows what kind of changes that has been developed to meet the users demand.

    The report brings up two important aspects; internet security and mobility. To show the important changes within these areas, the report compares the old protocol with the new one. Furthermore, the report also studies the world’s greatest test environment to this date. The aim of this is to show how the protocol behaves in reality and thereby get an insight to the specific areas that needs to be illustrated. To conclude the report, there is a broad discussion regarding the future of the two protocols and how this may effect the Internet in a future perspective.

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  • 319.
    Hedbrant, Joel
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Gustavsson, Marcus
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Automatiserad mjukvarusandlåda: En prototyp för automatisk installation och testning av öppna programvarors anslutningar i en dedikerad miljö2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna uppsats behandlar skapandet av en mjukvarusandlåda, en metod med syfte att automatiskt kunna installera programvara och avlyssna trafiken som skickas på nätverket i händelse av att programvaran gör anslutningar under eller efter installationen som inte begärts av användaren och som kan vara oönskade. När beteenden som kan klassas som olämpliga uppdagas i proprietär programvara finns det ofta ett företag som står bakom programvaran, men i många fall av programvara med öppen källkod finns det ingen att lägga skulden på. Därför är det viktigt att själv kunna utvärdera programvara och av denna anledning skapas denna metod för att en användare ska kunna testa programvara innan den driftsätts. För att uppfylla denna funktionalitet skrevs ett skript som sedan används för att testa en grupp olika programvaror.

    Resultaten av testerna visar på att vissa programvaror inte gjorde några anslutningar, vissa gjorde anslutningar som var nödvändiga och vissa gjorde anslutningar som kan ifrågasättas beroende på vilka krav som finns.

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  • 320.
    Hedenborg, Mathias
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Lundberg, Jonas
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Löwe, Welf
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Trapp, Martin
    Senacor Technologies AG, Germany.
    Approximating Context-Sensitive Program Information2015In: Proceedings Kolloquium Programmiersprachen (KPS 2015) / [ed] Jens Knoop, 2015Conference paper (Other academic)
    Abstract [en]

    Static program analysis is in general more precise if it is sensitive to execution contexts (execution paths). In this paper we propose χ-terms as a mean to capture and manipulate context-sensitive program information in a data-flow analysis. We introduce finite k-approximation and loop approximation that limit the size of the context-sensitive information. These approximated χ-terms form a lattice with a finite depth, thus guaranteeing every data-flow analysis to reach a fixed point. 

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  • 321.
    Hedenström, Kerstin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Programmering på gymnasiet: En studie av viktiga faktorer i programmeringsundervisningen på gymnasiet2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Denna rapport har sammanställts i syfte att beskriva vilka faktorer i undervisningen som kan vara viktiga när det gäller elevers måluppfyllelse på gymnasiets programmeringskurser. Med utgångspunkt från gjord textanalys har frågeställningar om vad programmering innebär, elevers syn och förväntningar på en programmeringskurs, hur kursen kan utformas för att bättre möta elevernas individuella sätt att lära sig samt hur elevers kunskapsutveckling kan påverkas på ovannämnda kurs behandlats. En enkätstudie bland gymnasielärare i programmering gjordes även för att få deras syn på frågeställningar kring val av programmeringsspråk och dess eventuella påverkan. Studien visar att en framgångsfaktor är motiverade elever. Motivationen kan ibland påverkas av vilket programmeringsspråk som används i undervisningen. Då det ofta finns stor spridning bland eleverna när det gäller deras tidigare kunskaper och inställning till programmering samt deras varierande förväntningar på kursen är även lärarens förmåga att anpassa undervisningen efter olika omständigheter en viktig framgångsfaktor i undervisningen.

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  • 322.
    Hedin, Andreas
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    CRAMO: Continuously Rendered Aerial Maps with Open Data2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    One issue with a lot of the free aerial satellite maps that exists is the actuality of the acquired images in terms of the acquisition date. A lot of times the images are a few years old and will not represent the current reality. This project will try and mitigate this by using free open data from the Copernicus directive supplied by the European Space Agency ESA and use that to create maps. By doing this the ability to have daily updated aerial satellite maps occurs and that could be really interesting for scientific and commercial purposes. To make this work an automated process was created that downloaded the images from Copernicus and processed them with GDAL to create the maps. The process deals with the issues of mosaicing, reprojection and unattended downloads amongst other things. In the results, there is a comparison between three different maps to give a comparison and an idea of how big of a map the process can handle in a reasonable time. 

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  • 323.
    Helleboogh, Alexander
    et al.
    Katholieke University Leuven.
    Holvoet, Tom
    Katholieke University Leuven.
    Weyns, Danny
    Katholieke University Leuven.
    Berbers, Y.
    Katholieke University Leuven.
    Extending time management support for multi-agent systems2005In: Lecture Notes in Computer Science, ISSN 0302-9743, E-ISSN 1611-3349, Vol. 3415, p. 37-48Article in journal (Refereed)
    Abstract [en]

    Time management is essential when simulating multi-agent systems (MASs) as it allows consistent and repeatable simulation runs. So far, time management lacks support to express the timing requirements of a simulation explicitly and at an abstraction level appropriate for MAS developers. Moreover, integrating time management into a MAS requires the developer to alter the design of the MAS. In this paper, we first propose semantic duration models to capture timing requirements that reflect the semantics of MAS activities in an explicit model. Second, we present a time management infrastructure that starts from a semantic duration model description to integrate all time management functionality into a MAS transparently, i.e. without requiring the developer to alter the design of the MAS. We use aspect-oriented programming technology as it allows separation of concerns, a crucial software engineering requirement. As a case, we apply our approach to the Packet-World.

  • 324.
    Hellström, Martin
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Företagsportal i WordPress2010Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Today there are several Webb Content Management Systems that helps Web developers to quickly get started with a Web application. Wordpress is primarily a blog application, but can easily be used as an cms-system. With a little knowledge of the scripting lanugage PHP you can use "plugins", "functions" and "widgets" to modify a WordPress application. This report will use WordPress for creating a portal for companies. In this portal you will be able to search for companies and categories by tags, categorynames or companynames. The visitor get search-help with ajax.

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  • 325.
    Herault, Romain Christian
    Linnaeus University, Faculty of Technology, Department of Media Technology.
    Application for Customisable Interaction with Physical Objects: A Tool for Speech and Language Therapists2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Physical objects with digital properties are being used more and more by the public. One such term for these artefacts include "the Internet of Things''. Most of these objects are often impossible to further modify or customise, and thus serve just the single purpose intended by their creators. This thesis explores the possibility of customising physical objects in order to provide an affordable and flexible way of interacting with them.

    A prototype, involving a mobile phone application (Android) and wireless sensor technology (NFC tags), was developed for the medical domain of speech and language therapy. The system, developed in close association with two therapists, allows the customisation of current speech and language exercise and associated material. It is designed to also assist with logging the patient interactions during the conduction of such exercises. The proposed solution has been tested and validated by medical experts, and its user interface evaluated by non-patient users.

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  • 326.
    Hermansson, Christopher
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Johansson, Sebastian
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    IPv6 - Gatewayredundans: Snabbt nog?2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Unlike earlier versions of the Internet Protocol, IPv6 have native support for gateway redundancy. By using more than one gateway, Neighbor Unreachability Detection supports automatic switching to a new gateway in the case the active one fails. Before IPv6 you had to rely on external solutions to achieve this kind of redundancy. The main question that is set in the report is if the built-in support for gateway redundancy in IPv6 is fast enough to be used independently, without the use of external solutions. In order to obtain a value about what was “fast enough” we have, by reading previous research about how users experience delay, concluded that a delay must not exceed ten seconds. The report also examines if there are external solutions for gateway redundancy that operates quick enough, and if there are other situations where you might prefer an external solution over Neighbor Unreachability Detection. After a number of experiments we’ve been able to conclude that, according to users, the native support for gateway redundancy in IPv6 is not working fast enough to independently solve the task. Experiments described in the report also shows that an external First Hop Redundancy Protocol has good potential to restore communication fast enough for a user to find the delay acceptable. Furthermore the work confirms that there are situations where you might prefer a First Hop Redundancy Protocol over Neighbor Unreachability Detection.

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  • 327.
    Hermansson, Christopher
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Johansson, Sebastian
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Segmentering av lokala nätverk - För mikro- och småorganisationer2010Independent thesis Basic level (university diploma), 5 credits / 7,5 HE creditsStudent thesis
    Abstract [en]

    The purpose of this report is to describe a number of approaches that can be used when you are in need of dividing a local area network in a number of segments, and with that also be able to control how data traffic is allowed to traverse between the different segments. The solutions that are presented are focused towards micro and small companies.The reason that we have chosen to work with this matter is that we believe it is important for organizations to have a structured and segmented design of its internal computer network.We have been working by in advance collecting information about various techniques that might solve our problem, and then testing different scenarios using these techniques. Data have been collected after each tested scenario and compiled in statistical form in order to determine which method that was preferable.We have been testing solutions were you segment the network in a layer 2 switch while you allow or deny communication between the segments in a router, and also solutions were you use a layer 3 switch. In that way you can let the routing be performed in the switch, which leads to significantly lower load on the router. The result was that if you are about to segment a local area network it is recommended that you use VLAN and ACL:s, and possibly in combination with a firewall.The final result of this report is that a solution using the “router on a stick”-technique is the cheapest one, and probably the one that most small companies would get along with. However, the solution that you choose depends completely on how much money you want to spend on your network, and also what the needs are.

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    Segmentering av lokala nätverk - För mikro- och småorganisationer
  • 328.
    Hertel, Andreas
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Preconditions, Potentials and Benefits of ITIL and the ISO 20000 Certification for Small Sized Companies2007Student thesis
    Abstract [en]

    The Information Technology (IT) becomes more and more a crucial factor for enterprises to enable their business. Moreover, the business model for a noticeable part of nowadays companies fully depends on a capable IT infrastructure. Therefore, the management of the IT infrastructure and the services provided by the IT organisation are essential for the business success of enterprises.

    This IT Infrastructure Library (ITIL) is based on best practices and describes all relevant IT service management processes. Additionally, the ISO 20000 standard provides approaches for the continuous improvement of IT service management and offers also the possibility of the certification of IT organisations. However, especially small and mid-sized enterprises (SME) need help to gather the knowledge of the general application, a further implementation and the related advantages of ITIL.

    The thesis is concentrated on whether and how the ITIL best practices are applicable in order to improve the IT service provision of SME's. Additionally, the content of the ISO 20000 standard and its certification process is considered. By answering research questions in the areas of implementation and evaluation the results are reflected to the specifics of SME's. Consequently, the ITIL best practice approaches are generally applicable independently from the size of an organisation. Furthermore, SME's are able to benefit from ITIL and apply for an ISO 20000 certification. The necessary preconditions and proceedings for the introduction of ITIL and ISO 20000 are also considered.

  • 329.
    Hjelm, Sofia
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Evaluation of JavaScript frameworks: Why should you use them?2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    JavaScript is today’s most common client-side programming language for the web. Choosing the most adapted framework for each and every project can optimize the development process and increase profits. Developers often lack knowledge about what to prioritize when choosing a framework and very little previous research regarding this subject area is available. This thesis investigates two JavaScript client-side frameworks and answers the questions of why you should use a framework when developing applications. This thesis also investigates why a company should develop a new framework, when equivalent open-source alternatives are available. To be able to answer the questions interviews with developers were conducted. The results are that using a framework can optimize the development process regarding time and complexity, but learning a new framework can be difficult. In rare cases it is a great idea to develop a new framework for a certain project, but it is often not worth it. Developers also seem to choose experience of using a framework over performance.

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  • 330.
    Hmidi, Mehdi
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Formation Control and UAV Path Finding Under Uncertainty: A contingent and cooperative swarm intelligence approach2020Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Several of our technological breakthroughs are influenced by types of behavior and structures developed in the natural world, including the emulation of swarm in- telligence and the engineering of artificial synapses that function like the human mind. Much like these breakthroughs, this report examines emerging behaviors across swarms of non-communicating, adaptive units that evade obstacles while find- ing a path, to present a swarming algorithm premised on a class of local rule sets re- sulting in a Unmanned Aerial Vehicle (UAV) group navigating together as a unified swarm. Primarily, this method’s important quality is that its rules are local in nature. Thus, the exponential calculations which can be supposed with growing number of drones, their states, and potential tasks are remedied. To this extent, the study tests the algorithmic rules in experiments to replicate the desired behavior in a bounded virtual space filled with simulated units. Simultaneously, in the adaptation of natural flocking rules the study also introduces the rule sets for goal seeking and uncertainty evasion. In effect, the study succeeds in reaching and displaying the desired goals even as the units avoid unknown before flight obstacles and inter-unit collisions with- out the need for a global centralized command nor a leader based hierarchical system.

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  • 331.
    Holmgren, Johan
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Stewén, Mikael
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Serious games med rökdykningssimulering2007Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [sv]

    Utbildning och träning av rökdykning inom räddningtjänsten är idag både dyrt och

    tidskrävande. Vid praktisk träning måste räddningstjänsten bege sig ut till befintliga

    övningsområden och ta med sig en stor mängd utrustning: luftpaket, skyddskläder, radio etc. Detta gör det till ett omfattande och kostsamt moment. Detta öppnar tankebanor för alternativ och komplement till befintlig utbildning och träning.

    Serious games finns idag i många former och är ett utbildnings och rekryteringsredskap som bygger på datorstödd inlärning. Med detta menas att ett Serious game är ett spel som har som huvudsyfte att lära ut och om möjlighet vara underhållande under tiden. Man kan genom denna teknik simulera verkliga situationer i realistiska miljöer med hjälp av verklighetsliknande kommunikationsprotokoll. Denna studie handlar om vilka huvudsakliga faktorer som är viktiga för ett Serious game. Vidare undersöks på vilket sätt ett Serious game

    ska anpassas för svensk Räddningstjänst med inriktning på sökning och kommunikation vid rökdykningsträning och utbildning.

    Vi har kommit fram till att följande huvudsakliga faktorer är viktiga för ett Serious game som är inriktat på förstapersonsimulering: Utvärdering, administration, grafik, underhållning, tutorials och dynamik. Vi har även kommit fram till att vid utveckling av en träningssimulator för rökdykning bör man använda befintliga inlärningsteorier, SDK som utvecklingsverktyg.

    Denna studie öppnar även möjligheter för andra att fortsätta och genomföra utveckling av en riktig prototyp till Räddningstjänsten, utifrån våra resultat. Studien kan också ses som enklare underlag vid skapandet av ett Serious game av typen förstapersonsimulator.

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  • 332.
    Holst, Andy
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Automatic Transcript Generator for Podcast Files2010Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In the modern world, Internet has become a popular place, people with speech hearing disabilities and search engines can't take part of speech content in podcast les. In order to solve the problem partially, the Sphinx decoders such as Sphinx-3, Sphinx-4 can be used to implement a Auto Transcript Generator application, by coupling already existing large acoustic model, language model and a existing dictionary, or by training your own large acoustic model, language model and creating your own dictionary to support continuous speaker independent speech recognition system.

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  • 333.
    Honar, Elnaz
    et al.
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Mortazavi Jahromi, Seyed AmirHossein
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    A Framework for Call Graph Construction2010Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In object oriented programming, a Call Graph represents the calling relationships between the program’s methods. To be more precise, a Call Graph is a rooted directed graph where each node of the graph represents a method and each edge (u, v) represents a method call from method u to method v.

    Focus of this thesis is on building a framework for Call Graph construction algorithms which can be used in program analysis. Our framework is able to be initialized by different front-ends and constructs various Call Graph algorithms. Here, we instantiate framework with two bytecode readers (ASM and Soot) as front-ends and implement three Call Graph construction algorithms (CHA, RTA and CTA).

    At first, we used two above mentioned bytecode readers to read the bytecode of a specific Java program, then we found reachable methods for each invoked method; meanwhile we kept obtained details on our own data structures.  Creating data structures for storing required information about Classes, Methods, Fields and Statements, gives us a great opportunity to implement an independent framework for applying well known Call Graph algorithms. As a result of these data structures, Call Graph construction will not depend on bytecode readers; since, whenever we read the bytecode of a program, we accumulate all necessary points in pre-defined data structures and implement our Call Graphs based on this accumulated data.

    Finally, the result is a framework for different Call Graph construction algorithms which is the goal of this thesis. We tested and evaluated the algorithms with a variety of programs as the benchmark and compared the bytecode readers besides the three Call Graph algorithms in different aspects.

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  • 334.
    Hoppe, H. Ulrich
    et al.
    Rhine-Ruhr Institute for Applied System Innovation (RIAS), Germany.
    Müller, Maximilian
    Linnaeus University, Faculty of Technology, Department of Media Technology.
    Alissandrakis, Aris
    Linnaeus University, Faculty of Technology, Department of Media Technology.
    Milrad, Marcelo
    Linnaeus University, Faculty of Technology, Department of Media Technology.
    Schneegass, Christina
    Rhine-Ruhr Institute for Applied System Innovation (RIAS), Germany.
    Malzahn, Nils
    Rhine-Ruhr Institute for Applied System Innovation (RIAS), Germany.
    "VC/DC" - Video versus Domain Concepts in Comments to Learner-generated Science Videos2016In: Proceedings of the 24th International Conference on Computers in Education. India: Asia-Pacific Society for Computers in Education / [ed] Weiqin Chen et al., India: Asia-Pacific Society for Computers in Education, 2016, p. 172-181Conference paper (Refereed)
    Abstract [en]

    The recently finished EU project JuxtaLearn aimed at supporting students' learning of STEM subjects through the creation, exchange and discussion of learner-made videos. The approach is based on an eight-stage activity cycle in the beginning of which teachers identify specific "stumbling blocks" for a given theme (or "tricky topic"). In JuxtaLearn, video comments were analyzed to extract information on the learners' acquisition and understanding of domain concepts, especially to detect problems and misconceptions. These analyses were based on mapping texts to networks of concepts ("network-text analysis") as a basis for further processing. In this article we use data collected from recent field trials to shed light on what is actually discussed when students share their own videos in science domains. Would the aspect of video-making dominate over activities related to a deepening of domain understanding? Our findings indicate that there are different ways of balancing both aspects and interventions will be needed to bring forth the desired blend.

  • 335.
    Houssein, Hatem
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Are ORMs the end of stored procedures?2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Stored procedures are used as the current database logic for SAAB’s data model of the fighter aircraft JAS-39 Gripen electrical schemas. Since the database model was developed in 2000, a research and tests needed to be carried out to decide on whether updating the database to today's technology is applicable. Therefore, Object-Relational Mapping (ORM) is to be researched, tested and compared to stored procedures using test-driven development (TDD)concerning an important factor, that Stored procedures are well-known for, which is querying performance of the database. Moreover, how maintainability and flexibility [1] can affect decision between Stored procedures or migrating to ORM based on our subjective experience. NHibernate and Entity Framework are the two ORM solutions considered sinceSAAB uses C# in this project. The process of this project is run using scrum of the agile software development to maintain an iterative progress throughout the project timeline. In this paper, the process and methodology are covered in details and also the comparison with the test results. These results eventually lead us to the answer that ORM is not a suitable technology, and stored procedures still dominate the querying performance for SAAB’scurrent database.

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  • 336.
    Hui, Wu
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Visualization of Bags2013Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The purpose of this thesis is to develop a toolkit to visualize bag calculations for teaching. We take full advantage of interaction techniques in Computer Science to achieve it, which could lead to a modern and impressive way for teaching.

      In this thesis, the developed toolkit is going to show the bag calculations and corresponding animations interactively and aesthetically which make new learners easier to acquire the concept of multiset.

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  • 337.
    Huss, Niklas
    Linnaeus University, Faculty of Science and Engineering, School of Computer Science, Physics and Mathematics.
    Real Time Ray Tracing2004Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Ray tracing has for a long time been used to create photo realistic images, but due to complex calculations done per pixel and slow hardware, the time to render a frame has been counted in hours or even days and this can be drawback if a change of a scene cannot be seen instantly. When ray tracing a frame takes less than a second to render we call it “real time ray tracing” or “interactive ray tracing” and many solutions have been developed and some involves distributing the computation to different computers interconnected in a very fast network (100 Mbit or higher). There are some drawbacks with this approach because most people do not have more than one computer and if they have, the computers are most likely not connected to each other.

    Since the hardware of today is fast enough to render a pretty complex image within minutes it should be possible to achieve real time ray tracing by combining many different methods that has been developed and reduce the render time.

    This work will examine what has to be sacrificed in image quality and complexity of static scenes, in order to achieve real time frame rate with ray tracing on a single computer. Some of the methods that will be covered in this work are frame optimizations, secondary rays optimization, hierarchies, culling, shadow caching, and sub sampling.

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  • 338.
    Hytter, Mats
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Egonsson, Anna-Carin
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Reservrutiner vid arbete med elektronisk journal: - nödvändigt ont eller förutseende arbetssätt?2007Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Since information technology has become the main carrier of information in healthcare service, we can see how these organizations now face a number of new threats. The treaths against information support can be either internal or external. An internal threat can for example be lack of security thinkning, whereas external threats can be power failures.

    The essay is a survey over and an inventory of backup procedures and routines in the county council of Kronoberg, Sweden.

    Data was obtained by sending out a questionnaire via county council intranet. 200 users of the EHR in the county council were selected; 50 physicians, 50 nurses, 50 assistant nurses and 50 medical secretaries. A total of 100 persons answered the questionnaire (i.e. a response rate of 50 %).

    To sum up our result of the survey, we can make the following statements:

    • all of the respondents think that backup procedures and routines are important for the organization

    • relatively many are ignorant about the existence of backup routines and procedures

    • a serious conclusion of the survey, is that many respondents regards that documentation is done incorrectly from the backup procedures in to EHR after an incident or system failure (EHR)

    • the majority of the units management staff/management teams at the micro system level has not revised the backup routines on a regular basis.

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  • 339.
    Håkansson, Jesper
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Badran, Sherief
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Evaluating cyclomatic complexity on functional JavaScript2016Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Bugs in software is a very common problem, code reviews can help to catch

    bugs early on and detect which code is the most complex and may introduce

    bugs but when the code base is very large it can be costly to review all the

    code. Cyclomatic complexity can be used to give an indication of how complex

    the system source code is and help the developers to select which code they

    should review. But when measuring cyclomatic complexity on code written

    according to the functional paradigm, McCabe’s formula will not be sufficient

    since it is a formula most suitable for imperative code. Therefore we are

    making adaptations to a formula suited for pure functional languages in order

    to fit functional JavaScript. We are using an inductive empirical quantitative

    measurement method to calculate cyclomatic complexity on a directed graph

    implementation in order to define adaptations for functional JavaScript. Our

    results show a working adapted version of the formula. We have measured on

    a graph implemented in Haskell and on a corresponding functional JavaScript

    version which results in a cyclomatic complexity difference at only 0.375.

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  • 340.
    Hönel, Sebastian
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Temporal data analysis facilitating recognition of enhanced patterns2015Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Assessing the source code quality of software objectively requires a well-defined model. Due to the distinct nature of each and every project, the definition of such a model is specific to the underlying type of paradigms used. A definer can pick metrics from standard norms to define measurements for qualitative assessment. Software projects develop over time and a wide variety of re-factorings is applied tothe code which makes the process temporal. In this thesis the temporal model was enhanced using methods known from financial markets and further evaluated using artificial neural networks with the goal of improving the prediction precision by learning from more detailed patterns. Subject to research was also if the combination of technical analysis and machine learning is viable and how to blend them. An in-depth selection of applicable instruments and algorithms and extensive experiments were run to approximate answers. It was found that enhanced patterns are of value for further processing by neural networks. Technical analysis however was not able to improve the results, although it is assumed that it can for an appropriately sizedproblem set.

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  • 341.
    Hönel, Sebastian
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Ericsson, Morgan
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Löwe, Welf
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Wingkvist, Anna
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Bayesian Regression on segmented data using Kernel Density Estimation2019In: 5th annual Big Data Conference: Linnaeus University, Växjö, Sweden, 5-6 December 2019, Zenodo , 2019Conference paper (Other academic)
    Abstract [en]

    The challenge of having to deal with dependent variables in classification and regression using techniques based on Bayes' theorem is often avoided by assuming a strong independence between them, hence such techniques are said to be naive. While analytical solutions supporting classification on arbitrary amounts of discrete and continuous random variables exist, practical solutions are scarce. We are evaluating a few Bayesian models empirically and consider their computational complexity. To overcome the often assumed independence, those models attempt to resolve the dependencies using empirical joint conditional probabilities and joint conditional probability densities. These are obtained by posterior probabilities of the dependent variable after segmenting the dataset for each random variable's value. We demonstrate the advantages of these models, such as their nature being deterministic (no randomization or weights required), that no training is required, that each random variable may have any kind of probability distribution, how robustness is upheld without having to impute missing data, and that online learning is effortlessly possible. We compare such Bayesian models against well-established classifiers and regression models, using some well-known datasets. We conclude that our evaluated models can outperform other models in certain settings, using classification. The regression models deliver respectable performance, without leading the field.

  • 342.
    Hönel, Sebastian
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Ericsson, Morgan
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Löwe, Welf
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Wingkvist, Anna
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Importance and Aptitude of Source code Density for Commit Classification into Maintenance Activities2019In: 2019 IEEE 19th International Conference on Software Quality, Reliability and Security (QRS) / [ed] Dr. David Shepherd, IEEE, 2019, p. 109-120Conference paper (Refereed)
    Abstract [en]

    Commit classification, the automatic classification of the purpose of changes to software, can support the understanding and quality improvement of software and its development process. We introduce code density of a commit, a measure of the net size of a commit, as a novel feature and study how well it is suited to determine the purpose of a change. We also compare the accuracy of code-density-based classifications with existing size-based classifications. By applying standard classification models, we demonstrate the significance of code density for the accuracy of commit classification. We achieve up to 89% accuracy and a Kappa of 0.82 for the cross-project commit classification where the model is trained on one project and applied to other projects. Such highly accurate classification of the purpose of software changes helps to improve the confidence in software (process) quality analyses exploiting this classification information.

  • 343.
    Idrizi, Florim
    et al.
    Tetovo State University, Macedonia.
    Rustemi, Avni
    Tetovo State University, Macedonia.
    Dalipi, Fisnik
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM), Department of Computer Science. Tetovo State University, Macedonia.
    A new modified sorting algorithm: A comparison with state of the art2017In: 2017 6th Mediterranean Conference on Embedded Computing (MECO), IEEE, 2017, p. 419-424Conference paper (Refereed)
    Abstract [en]

    Choosing the right method to sort numbers has a huge effect on how quickly a computer can process a task. The most used sorting algorithms today have been discovered years ago, and to this day, they have been the best for the job as there was no other competitive algorithm. Through this paper, we make an analysis and comparison between the state of the art algorithms in sorting and based on their analogy of functionality, we propose a new modified sorting algorithm. We then present a brief description of the new modified algorithm, conduct comparisons with the state of the art, and finally we give conclusions about the performance of the proposed algorithm versus the most popular sorting algorithms. Moreover, we highlight the benefits of using this algorithm in different fields by various business companies or software developers, in cases when they need faster and easier sorting for their data management.

  • 344.
    Iftikhar, Muhammad Usman
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM), Department of Computer Science. Faculty of Engineering Science, Department of Computer Science, KU Leuven, Belgium.
    A Model-Based Approach to Engineer Self-Adaptive Systems with Guarantees2017Doctoral thesis, monograph (Other academic)
    Abstract [en]

    Modern software systems are increasingly characterized by uncertainties in the operating context and user requirements. These uncertainties are difficult to predict at design time. Achieving the quality goals of such systems depends on the ability of the software to deal with these uncertainties at runtime. A self-adaptive system employs a feedback loop to continuously monitor and adapt itself to achieve particular quality goals (i.e., adaptation goals) regardless of uncertainties. Current research applies formal techniques to provide guarantees for adaptation goals, typically using exhaustive verification techniques. Although these techniques offer strong guarantees for the goals, they suffer from well-known state explosion problem. In this thesis, we take a broader perspective and focus on two types of guarantees: (1) functional correctness of the feedback loop, and (2) guaranteeing the adaptation goals in an efficient manner. To that end, we present ActivFORMS (Active FORmal Models for Self-adaptation), a formally founded model-driven approach for engineering self-adaptive systems with guarantees. ActivFORMS achieves functional correctness by direct execution of formally verified models of the feedback loop using a reusable virtual machine. To efficiently provide guarantees for the adaptation goals with a required level of confidence, ActivFORMS applies statistical model checking at runtime. ActivFORMS supports on the fly changes of adaptation goals and updates of the verified feedback loop models that meet the changed goals. To demonstrate the applicability and effectiveness of the approach, we applied ActivFORMS in several domains: warehouse transportation, oceanic surveillance, tele assistance, and IoT building security monitoring.

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  • 345.
    Iftikhar, Muhammad Usman
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Lundberg, Jonas
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Weyns, Danny
    Linnaeus University, Faculty of Technology, Department of Computer Science. Katholieke Univ Leuven, Leuven, Belgium.
    A Model Interpreter for Timed Automata2016In: Leveraging Applications of Formal Methods, Verification and Validation: Foundational Techniques, PT I, Springer, 2016, p. 243-258Conference paper (Refereed)
    Abstract [en]

    In the model-centric approach to model-driven development, the models used are sufficiently detailed to be executed. Being able to execute the model directly, without any intermediate model-to-code translation, has a number of advantages. The model is always up-to-date and runtime updates of the model are possible. This paper presents a model interpreter for timed automata, a formalism often used for modeling and verification of real-time systems. The model interpreter supports real-time system features like simultaneous execution, system wide signals, a ticking clock, and time constraints. Many existing formal representations can be verified, and many existing DSMLs can be executed. It is the combination of being both verifiable and executable that makes our approach rather unique.

  • 346.
    Iftikhar, Muhammad Usman
    et al.
    Linnaeus University, Faculty of Technology, Department of Computer Science. Linnaeus University.
    Weyns, Danny
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    ActivFORMS: Active Formal Models for Self-adaptation2014In: Proceedings of the 9th International Symposium on Software Engineering for Adaptive and Self-Managing Systems, ACM Press, 2014, p. 125-134Conference paper (Refereed)
    Abstract [en]

    Self-adaptation enables a software system to deal autonomously with uncertainties, such as dynamic operating conditions that are difficult to predict or changing goals. A common approach to realize self-adaptation is with a MAPE-K feedback loop that consists of four adaptation components: Monitor, Analyze, Plan, and Execute. These components share Knowledge models of the managed system, its goals and environment. To provide guarantees of the adaptation goals, state of the art approaches propose using formal models of the knowledge. However, less attention is given to the formalization of the adaptation components themselves, which is important to provide guarantees of correctness of the adaptation behavior (e.g., does the execute component execute the plan correctly?). We propose Active FORmal Models for Self-adaptation (ActivFORMS) that uses an integrated formal model of the adaptation components and knowledge models. The formal model is directly executed by a virtual machine to realize adaptation, hence active model. The contributions of ActivFORMS are: (1) the approach assures that the adaptation goals that are verified offline are guaranteed at runtime, and (2) it supports dynamic adaptation of the active model to support changing goals. We show how we have applied ActivFORMS for a small-scale robotic system

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  • 347.
    Iftikhar, Muhammad Usman
    et al.
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM), Department of Computer Science. Linnaeus University.
    Weyns, Danny
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM), Department of Computer Science.
    Assuring System Goals Under Uncertainty with Active Formal Models of Self-adaptation2014In: Companion Proceedings of the 36th International Conference on Software Engineering, ACM Publications, 2014, p. 604-605Conference paper (Refereed)
    Abstract [en]

    Designing software systems with uncertainties, such as incomplete knowledge about changing system goals, is challenging. One approach to handle uncertainties is self-adaptation, where a system consists of a managed system and a managing system that realizes a feedback loop. The promise of self-adaptation is to enable a system to adapt itself realizing the system goals, regarding uncertainties. To realize this promise it is critical to provide assurances for the self-adaptive behaviours. Several approaches have been proposed that exploit formal methods to provide these assurances. However, an integrated approach that combines: (1) seamless integration of offline and online verification (to deal with inherent limitations of verification), with (2) support for runtime evolution of the system (to deal with new or changing goals) is lacking. In this paper, we outline a new approach named Active FORmal Models of Self-adaptation (ActivFORMS) that aims to deal with these challenges. In ActivFORMS, the formal models of the managing system are directly deployed and executed to realize self-adaptation, guaranteeing the verified properties. Having the formal models readily available at runtime paves the way for: (1) incremental verification during system execution, and (2) runtime evolution of the self-adaptive system. Experiences with a robotic system show promising results.

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  • 348.
    Ihantola, Petri
    et al.
    Tampere University of Technology, Finland.
    Vihavainen, Arto
    University of Helsinki, Finland.
    Ahadi, Alireza
    University of Technology, Australia.
    Butler, Matthew
    Monash University, Australia.
    Börstler, Jürgen
    Blekinge Institute of Technology.
    Edwards, Stephen H.
    Virginia Tech, USA.
    Isohanni, Essi
    Tampere University of Technology, Finland.
    Korhonen, Ari
    Aalto University, Finland.
    Petersen, Andrew
    University of Toronto, Canada.
    Rivers, Kelly
    Carnegie Mellon University, USA.
    Rubio, Miguel Ángel
    University of Granada, Spain.
    Sheard, Judy
    Monash University, Australia.
    Skupas, Bronius
    Vilnius University, Lithuania.
    Spacco, Jaime
    Knox College, USA.
    Szabo, Claudia
    The University of Adelaide, Australia.
    Toll, Daniel
    Linnaeus University, Faculty of Technology, Department of Computer Science.
    Educational Data Mining and Learning Analytics in Programming: Literature Review and Case Studies2015In: Proceedings of the 2015 ITiCSE on Working Group Reports / [ed] Program ChairsNoa Ragonis Beit Berl College and Technion-ITT, Israel Päivi Kinnunen Aalto University, Finland, New York: ACM Press, 2015, p. 41-63Conference paper (Refereed)
    Abstract [en]

    Educational data mining and learning analytics promise better understanding of student behavior and knowledge, as well as new information on the tacit factors that contribute to student actions. This knowledge can be used to inform decisions related to course and tool design and pedagogy, and to further engage students and guide those at risk of failure. This working group report provides an overview of the body of knowledge regarding the use of educational data mining and learning analytics focused on the teaching and learning of programming. In a literature survey on mining students’ programming processes for 2005–2015, we observe a significant increase in work related to the field. However, the majority of the studies focus on simplistic metric analysis and are conducted within a single institution and a single course. This indicates the existence of further avenues of research and a critical need for validation and replication to better understand the various contributing factors and the reasons why certain results occur. We introduce a novel taxonomy to analyse replicating studies and discuss the importance of replicating and reproducing previous work. We describe what is the state of the art in collecting and sharing programming data. To better understand the challenges involved in replicating or reproducing existing studies, we report our experiences from three case studies using programming data. Finally, we present a discussion of future directions for the education and research community.

  • 349.
    Imran, Ali Shariq
    et al.
    Norwegian University of Science and Technology (NTNU), Norway.
    Kastrati, Zenun
    Norwegian University of Science and Technology (NTNU), Norway.
    Pedagogical document classification and organization using domain ontology2016In: Learning and Collaboration Technologies: Third International Conference, LCT 2016, Held as Part of HCI International 2016, Toronto, ON, Canada, July 17-22, 2016, Proceedings / [ed] Panayiotis Zaphiris & Andri Ioannou, Springer, 2016, p. 499-509Conference paper (Refereed)
    Abstract [en]

    One of the challenges faced by today’s web is the abundance of unstructured and unorganized information available on the Internet in form of educational documents, lecture notes, presentation slides, and multimedia recordings. Accessing and retrieving the massive amount of such resources are not an easy task, especially educational resources of pedagogical nature. Much of the pedagogical content available on Internet comes from blogs, wikis, posts with little or no metadata, that suffer from the same dilemma. The content is out there but way out of the reach of the intended audience. For content to be readily available, it has to be properly organized into different categories and structured into an appropriate format using metadata. This paper addresses this issue by proposing an automated approach using ontology-based document classification. The paper presents a case study and describes how our proposed ontology model can be used to classify educational documents into predefined categories.

  • 350.
    Imran, Ali Shariq
    et al.
    Norwegian University of Science and Technology, Norway.
    Kastrati, Zenun
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Svendsen, Torbjorn Karl
    Norwegian University of Science and Technology, Norway.
    Kurti, Arianit
    Linnaeus University, Faculty of Technology, Department of computer science and media technology (CM).
    Text-Independent Speaker ID Employing 2D-CNN for Automatic Video Lecture Categorization in a MOOC Setting2019In: 2019 IEEE 31st International Conference on Tools with Artificial Intelligence (ICTAI), IEEE Press, 2019, p. 273-277Conference paper (Refereed)
    Abstract [en]

    A new form of distance and blended education has hit the market in recent years with the advent of massive open online courses (MOOCs) which have brought many opportunities to the educational sector. Consequently, the availability of learning content to vast demographics of people and across locations has opened up a plethora of possibilities for everyone to gain new knowledge through MOOCs. This poses an immense issue to the content providers as the amount of manual effort required to structure properly and to organize the content automatically for millions of video lectures daily become incredibly challenging. This paper, therefore, addresses this issue as a small part of our proposed personalized content management system by exploiting the voice pattern of the lecturer for identification and for classifying video lectures to the right speaker category. The use of Mel frequency Cepstral coefficients (MFCC) as 2D input features maps to 2D-CNN has shown promising results in contrast to machine learning and deep learning classifiers - making text-independent speaker identification plausible in MOOC setting for automatic video lecture categorization. It will not only help categorize educational videos efficiently for easy search and retrieval but will also promote effective utilization of micro-lectures and multimedia video learning objects (MLO).

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