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  • 301.
    Anliot, Manne
    Linköpings universitet, Institutionen för systemteknik.
    Volume Estimation of Airbags: A Visual Hull Approach2005Independent thesis Basic level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    This thesis presents a complete and fully automatic method for estimating the volume of an airbag, through all stages of its inflation, with multiple synchronized high-speed cameras.

    Using recorded contours of the inflating airbag, its visual hull is reconstructed with a novel method: The intersections of all back-projected contours are first identified with an accelerated epipolar algorithm. These intersections, together with additional points sampled from concave surface regions of the visual hull, are then Delaunay triangulated to a connected set of tetrahedra. Finally, the visual hull is extracted by carving away the tetrahedra that are classified as inconsistent with the contours, according to a voting procedure.

    The volume of an airbag's visual hull is always larger than the airbag's real volume. By projecting a known synthetic model of the airbag into the cameras, this volume offset is computed, and an accurate estimate of the real airbag volume is extracted.

    Even though volume estimates can be computed for all camera setups, the cameras should be specially posed to achieve optimal results. Such poses are uniquely found for different airbag models with a separate, fully automatic, simulated annealing algorithm.

    Satisfying results are presented for both synthetic and real-world data.

  • 302.
    Annerhult, Adam
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Filosofiska fakulteten.
    Distribuerad kognition i cockpit Nu och Då2014Independent thesis Basic level (degree of Bachelor), 12 poäng / 18 hpOppgave
    Abstract [sv]

    Denna studie replikerar Hutchins studie 1995 ”How a cockpit remember its speed”, för att undersöka skillnader och likheter i dagens cockpits.

    Syftet med studien är att ta reda på ifall dagens cockpit distribuerar kognitionen på samma sätt som förr det vill säga används till exempel fartbuggar och andra artefakter på liknande sätt. Samt att ta reda på om det har ändrats mycket hur detta då påverkar cockpit kommer ihåg hastighet inför landning.

    För att få reda på detta så har observationer gjorts i cockpit under landning. Sammanlagt så observerades sex landningar. Under dessa observationer intervjuades också piloterna om hur de hade beskrivit cockpits minne av hastigheter.

    Resultatet i studien visar att det finns mycket som fortfarande fungerar på liknande sätt som tidigare. Mycket har digitaliserats och man kan spekulera i att det ha minskat piloternas kognitiva belastning då de inte behöver utföra lika många handlingar som förr, medan andra saker är nästintill identiska med hur det såg tidigare.

  • 303.
    Anstensen, Jan
    Linköpings universitet, Institutionen för systemteknik.
    An investigation of the possibility of defining a new conditional access application programming interface for digital television receivers2002Independent thesis Basic level (professional degree)Oppgave
    Abstract [en]

    Digital television broadcasters use conditional access (CA) systems to protect some of their services from being viewed by people not subscribing for these services. A manufacturer of digital television receivers develops applications to handle the CA systems that the receiver shall support. A problem for the application developer is that a CA application developed for one specific CA system is usually not reusable for other CA systems because of the differences between CA systems. The CA systems are different in both their application programming interfaces (API) as well as the types of functionality that they support.

    This master thesis presents a study of three APIs from different CA systems. The possibilities of defining a new CA API that supports all the functionality that is provided by existing CA APIs while still being as similar as possible to these existing APIs are investigated. The conclusion from the study is that it is not possible to define this new CA API because the studied CA systems are so different and only small parts of the provided functionality are shared between them.

  • 304.
    Ante, Wall
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska fakulteten.
    Google Maps som spelmotor för mobila plattformar2015Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [sv]

    Spel kan utvecklas på flera olika sätt med flera olika utmaningar. I detta arbete undersökts det hur lämpligt det ̈ar attutveckla och implementera ett spel tillsammans med Google Maps. Undersökningen testar hur det går att implementera vanliga element som förekommer i spel tillsammansmed Google Maps. Dessutom undersöks hur mycket dataanvändning som Google Maps använder för olika typer av kartor som den erbjuder. Detta har genomförts genom att implementera ett spel baserat på Google Maps som grundmoment i spelet och undersöker där ifrån resultatet av implementationen. ̈Aven förflyttning ̈over kartan undersökts och hur mer traditionella spelanspassade kontroller som joysticks anpassar sigtill Google Maps jämfört med dess normala interaktion undersöks. Undersökningen resulterar i att Google Maps erbjuder goda möjligheter att tillämpa vanliga spelelement. Dessutom visar undersökningen av datanvändingen att den normala kartypen ̈är mest effektivast medans terrängkartan användersig av mest nätversdata. Google Maps vanliga touchinteraktion visas lämpas sig mest för precisionförflyttningar och ger användare lättare att förstå interaktionen men andra typer av kartförflyttningar kan också tillämpas.

  • 305.
    Antelius, Daniel
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Link Extraction for Crawling Flash on the Web2015Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The set of web pages not reachable using conventional web search engines is usually called the hidden or deep web. One client-side hurdle for crawling the hidden web is Flash files.

    This thesis presents a tool for extracting links from Flash files up to version 8 to enable web crawling. The files are both parsed and selectively interpreted to extract links. The purpose of the interpretation is to simulate the normal execution of Flash in the Flash runtime of a web browser. The interpretation is a low level approach that allows the extraction to occur offline and without involving automation of web browsers. A virtual machine is implemented and a set of limitations is chosen to reduce development time and maximize the coverage of interpreted byte code.

    Out of a test set of about 3500 randomly sampled Flash files the link extractor found links in 34% of the files. The resulting estimated web search engine coverage improvement is almost 10%.

  • 306.
    Anton, Stevensson
    Linköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system.
    Distributed User Interfaces for the Web2017Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    New ways of interaction between users and their computing devices has revealed that users are not only interested in sharing their data, but their user interfaces as well. This calls for an extension of the traditional notion of user interfaces, to a notion where user interfaces span over multiple devices: Distributed User Interfaces (DUIs). The purpose of this thesis is to identify challenges in developing Web based DUIs, and the result is a JavaScript library that aids the development of these types of interfaces. The development has been driven in an explorative fashion, to discover techniques that is appropriate to use, when moving ideas from existing DUI frameworks for the desktop, to the Web. Soundness of the implementation has been evaluated by measuring properties of the library source code that indicates maintainability and extensibility. The conclusion is that the library has the potential of answering the needs for future DUI development targeting the Web.

  • 307.
    Antonsson, Andreas
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Kassander, Olivia
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Compelling interaction for large digital image archives2016Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Samhället idag sitter på ett stort kulturarv av bilder som nu digitaliserats i stora digitala bildarkiv. För att allmänheten ska få möjlighet att ta del av detta så har denna studie undersökt hur man kan skapa en interaktiv tjänst som ger åtkomst till ett stort antal bilder med en intresseväckande visuell upplevelse. För att besvara detta har en kvalitativ studie genomförts med en blandning av forskning genom design och fallstudie. Studiens har bestått av intervjuer med en intendent på Norrköpings stadsmuseum och fokusgrupper som besvarar målgruppens efterfrågan. Utifrån detta skapades designförslag som testades med hjälp av användbarhetstester och som därefter utvärderades genom en induktiv kvalitativ analys. Studiens resultat visar att skapandet av en interaktiv tjänst som ger åtkomst till ett stort antal bilder med en intresseväckande visuell upplevelse bör utgå från en tydlig och engagerande interaktion. Med bilder som får ta stor plats och med element som kan öka intresset i form av karta som visualliserar bildens position och tidslinje som ger möjlighet till filtrering.

  • 308.
    Antonsson, Daniel
    Linköpings universitet, Institutionen för systemteknik.
    A server application for Traffic Information Service: Broadcast2003Independent thesis Basic level (professional degree)Oppgave
    Abstract [en]

    The need for increased safety and efficiency in civil aviation is pushing the introduction of Automatic Dependent Surveillance - Broadcast (ADS-B). The basic principle of ADS-B is that each aircraft is able to communicate its position and status over a radio data link to surrounding aircraft. In this way each aircraft obtains a detailed picture of the surrounding traffic. During a period of transition from today's radar surveillance to ADS-B many aircraft will not be equipped with the new data link technology and will therefore be invisible to the ADS-B equipped aircraft. The Traffic Information Service - Broadcast (TIS-B) has been conceived to be the solution to this problem. TIS-B is defined as a broadcast surveillance service in which data from the ordinary ground radar system is transmitted from a ground station to airborne systems, providing an air situation picture of the non-ADS-B stations.

    The topics of this thesis are the definition and implementation of a TIS-B server. The presented solution is an evaluation TIS-B server that will receive data from a data-fusing tracker and provide one or several TIS-B ground stations with data filtered according to the settings of the server.

  • 309.
    Anundi, Daniel
    Linköpings universitet, Institutionen för datavetenskap.
    Estetiska upplevelser av interaktiva system med olika tempo och hastighet: en explorativ användarstudie2009Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    På senare år har intresset för att föra in estetik i MDI-teorin ökat kraftigt. Insikten om att användares känslor inför interaktiva artefakter spelar stor roll för tillfredställelsen och användarupplevelsen har medfört ett fokusskifte inom området och flertalet teorier om användares estetiska upplevelser av interaktion har framkommit. Detta arbete har tagit som utgångspunkt de teorier som siktar på att stödja designers arbete med att utforma estetiska interaktioner genom att identifiera manipulerbara attribut i artefakters interaktionsestetiska gestalt. En explorativ användarstudie har genomförts med målet att belysa hur upplevelsen av hastighet och tempo förändras genom införandet av animationer i ett gränssnitt. Resultaten visar på att toningsanimationer i övergångar i ett interaktivt system kan leda till ett långsammare och mjukare intryck av systemet men även att långsamma animationer i vissa fall kan leda till att systemet upplevs som snabbare. Upplevelsen av väntan har identifierats som en viktig faktor i ett systems uttryck av tempo och hastighet. Studien visar också att ett systems estetiska gestalt är en komplex konstruktion där såväl attribut i interaktionen som användarnas erfarenheter och förväntningar spelar in.

  • 310.
    Anwer, Rao Muhammad
    et al.
    Aalto Univ, Finland.
    Khan, Fahad
    Linköpings universitet, Institutionen för systemteknik, Datorseende. Linköpings universitet, Tekniska fakulteten.
    Laaksonen, Jorma
    Aalto Univ, Finland.
    Two-Stream Part-based Deep Representation for Human Attribute Recognition2018Inngår i: 2018 INTERNATIONAL CONFERENCE ON BIOMETRICS (ICB), IEEE , 2018, s. 90-97Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Recognizing human attributes in unconstrained environments is a challenging computer vision problem. State-of-the-art approaches to human attribute recognition are based on convolutional neural networks (CNNs). The de facto practice when training these CNNs on a large labeled image dataset is to take RGB pixel values of an image as input to the network. In this work, we propose a two-stream part-based deep representation for human attribute classification. Besides the standard RGB stream, we train a deep network by using mapped coded images with explicit texture information, that complements the standard RGB deep model. To integrate human body parts knowledge, we employ the deformable part-based models together with our two-stream deep model. Experiments are performed on the challenging Human Attributes (HAT-27) Dataset consisting of 27 different human attributes. Our results clearly show that (a) the two-stream deep network provides consistent gain in performance over the standard RGB model and (b) that the attribute classification results are further improved with our two-stream part-based deep representations, leading to state-of-the-art results.

  • 311.
    Anwer, Rao Muhammad
    et al.
    Aalto Univ, Finland.
    Khan, Fahad
    Linköpings universitet, Institutionen för systemteknik, Datorseende. Linköpings universitet, Tekniska fakulteten.
    van de Weijer, Joost
    Univ Autonoma Barcelona, Spain.
    Molinier, Matthieu
    VTT Tech Res Ctr Finland Ltd, Finland.
    Laaksonen, Jorma
    Aalto Univ, Finland.
    Binary patterns encoded convolutional neural networks for texture recognition and remote sensing scene classification2018Inngår i: ISPRS journal of photogrammetry and remote sensing (Print), ISSN 0924-2716, E-ISSN 1872-8235, Vol. 138, s. 74-85Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Designing discriminative powerful texture features robust to realistic imaging conditions is a challenging computer vision problem with many applications, including material recognition and analysis of satellite or aerial imagery. In the past, most texture description approaches were based on dense orderless statistical distribution of local features. However, most recent approaches to texture recognition and remote sensing scene classification are based on Convolutional Neural Networks (CNNs). The de facto practice when learning these CNN models is to use RGB patches as input with training performed on large amounts of labeled data (ImageNet). In this paper, we show that Local Binary Patterns (LBP) encoded CNN models, codenamed TEX-Nets, trained using mapped coded images with explicit LBP based texture information provide complementary information to the standard RGB deep models. Additionally, two deep architectures, namely early and late fusion, are investigated to combine the texture and color information. To the best of our knowledge, we are the first to investigate Binary Patterns encoded CNNs and different deep network fusion architectures for texture recognition and remote sensing scene classification. We perform comprehensive experiments on four texture recognition datasets and four remote sensing scene classification benchmarks: UC-Merced with 21 scene categories, WHU-RS19 with 19 scene classes, RSSCN7 with 7 categories and the recently introduced large scale aerial image dataset (AID) with 30 aerial scene types. We demonstrate that TEX-Nets provide complementary information to standard RGB deep model of the same network architecture. Our late fusion TEX-Net architecture always improves the overall performance compared to the standard RGB network on both recognition problems. Furthermore, our final combination leads to consistent improvement over the state-of-the-art for remote sensing scene classification. (C) 2018 International Society for Photogrammetry and Remote Sensing, Inc. (ISPRS). Published by Elsevier B.V. All rights reserved.

  • 312.
    Anzaldi, Davide
    Linköpings universitet, Institutionen för datavetenskap, RTSLAB - Laboratoriet för realtidssystem.
    ORWAR: a delay-tolerant protocol implemented on the Android platform2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The Aim of this thesis is to implement the "Opportunistic DTN Routing with Window-aware Adaptive Replication" (ORWAR) protocol on the Android platform.Delay-Tolerant Networks (DTNs) are particular mobile ad-hoc network (MANET) architectures that try to solve the issues related to the lack of point to point connectivity between the nodes of the network or between its sub-networks (partitions). The general approach is based on techniques of store-carry-forward of the messages whereby delivery can be achieved even in partitioned networks, though with mobility-dependent delays. DTNs can be considered as a means of communication for scenarios where infrastructure-based networks cannot be deployed or get dysfunctional for some reasons, such as in the case of a natural disaster or highly overloaded infrastructure. ORWAR is a DTN protocol that tries to exploit knowledge about the context of mobile nodes (speed, direction of movement and radio range) to estimate the size of a contact window in order to avoid the energy waste deriving from partial transmissions. This report presents the design and the implementation of the protocol on the Android platform. It then describes some functional tests together with an analysis of the energy consumption and the performance reachable on our test device Android Development Phone 1.

  • 313.
    Anzén, Philip
    Linköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system.
    Design av infotainment-system styrt av ögonrörelser i bilar: En explorativ studie för att ta fram ett förslag på hur man kan designa ett infotainment-system som har ögonrörelser som huvudsakliga interaktionsmetod med fokus på den funktionella designen.2014Independent thesis Basic level (degree of Bachelor), 12 poäng / 18 hpOppgave
    Abstract [sv]

    Denna studie har som syfte att ta fram ett designförslag på ett ögonrörelsestyrt infotainment-system samt utvärdera detta. Fokusen ligger på den funktionella design och dess för- och nackdelar. Studien tar upp tre olika designförslag varav ett valdes att göra en prototyp av. Prototypen skapades med hjälp av HTML5, Javascript och Python. Detta kopplades sedan samman med ett ögonrörelsesystem tillhörande Smart Eye AB. Prototypen användartestades och utvärderades med hjälp av en bilsimulator. Utvärderingen gjordes med hjälp av en enkät samt SUS-formulär. Enkäten resulterade i en kvalitativ utvärdering av prototypen medan SUS-värdet (69,88) pekar på att förbättringar bör göras för att öka den upplevda användbarheten. Studien innehåller även framtida förbättringsförslag för vidare utveckling. 

  • 314.
    Anzén, William
    et al.
    Linköpings universitet, Institutionen för datavetenskap.
    Borggren, Lukas
    Linköpings universitet, Institutionen för datavetenskap.
    Eveborn, Lukas
    Linköpings universitet, Institutionen för datavetenskap.
    Gustafsson, Viktor
    Linköpings universitet, Institutionen för datavetenskap.
    Holm, Greta
    Linköpings universitet, Institutionen för datavetenskap.
    Lindblom, Rasmus
    Linköpings universitet, Institutionen för datavetenskap.
    Ovik Karlsson, Fabian
    Linköpings universitet, Institutionen för datavetenskap.
    Sträng, Hanna
    Linköpings universitet, Institutionen för datavetenskap.
    von Koch, Christian
    Linköpings universitet, Institutionen för datavetenskap.
    Utformning av användbara webbapplikationer med fokus på navigerbarhet: En explorativ fallstudie av webapplikationen iBokhyllan2019Independent thesis Basic level (degree of Bachelor), 12 poäng / 18 hpOppgave
    Abstract [sv]

    Det har aldrig varit lika viktigt som idag att ta hänsyn till internetanvändarens flyktiga uppmärksamhet. Konsten att bevara denna uppmärksamhet är lika komplex som den är ung, och varje dag formuleras nya verktyg för just detta ändamål. Denna rapport ämnar undersöka hur man som webbdesigner kan utforma en webbapplikation som uppnår bra navigerbarhet och därmed god användbarhet, i syfte att inte förlora användares uppmärksamhet. Författarna av denna text utvecklade en webbapplikation i syfte att skaffa sig ett verktyg att kunna nyttja i experiment som ämnar svara på frågan. Efter en serie experiment med användare som testar webbapplikationen har författarna lyckats påvisa och mäta värdet hos webbapplikationselement såsom navigeringsfält, tilläggslänkar och sökfunktioner och deras effekt på webbapplikationen.

  • 315.
    Appelgren, Caroline
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Olsson, Lisa
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Ett branschperspektiv: normbrytning och stereotyper i reklam2014Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [en]

    På grund av stor konkurrens är det svårt att skapa reklam som fångar uppmärksamhet. Det finns olika verktyg för nå igenom mediaflödet. I den här studien undersöks orsaker och konsekvenser till användning av normbrytande- och stereotypisk kommunikation. Konsekvenser har tidigare studerats ur ett beteendevetarperspektiv. Studierna visar att reklam påverkar samhällets normer. Marknadskommunikativa orsaker tas inte upp och därför behövs en analys som lyfter fram för- och nackdelar ur reklambranschens perspektiv. Det förklarar varför stereotyper används och ger branschens intryck av konsekvenserna i att bryta eller förstärka normer. Den här studien har gjorts för att öka medvetenheten hos yrkesverksamma kommunikatörer. Datainsamling har gjorts genom kvalitativa intervjuer med sju yrkesverksamma kommunikatörer. Två reklamfilmer användes som diskussionsunderlag vid intervjuerna. Intervjuerna övergick sedan i mer allmänna frågor kring stereotyper, normer och normbrytande, informanterna fick reflektera över upplevda orsaker och konsekvenser. Slutsatser som kunnat dras från studien är att både normbrytning och stereotyper kan vara ett sätt att synas i dagens mediaflöde. Reklam är väldigt kundstyrt eftersom det är beställaren som tar störst risker med sitt varumärke och sin investering. Kommunikatörerna anser att deras största ansvar är gentemot beställaren. Stereotyper anses vara den säkra vägen. De identifieras snabbt och mycket slipper förklaras. I snabb kommunikation tar de inte onödig uppmärksamhet från budskapet. En nackdel med stereotyper är att de är opersonliga. De sticker inte ut ur mängden och reklamen glöms snabbt bort. En ytterligare nackdel med stereotyper anses vara att de påverkar samhället genom att förstärka fördomar och könsroller. Normbrytande reklam sticker ut och blir ihågkommen, vilket är en stor konkurrensfördel. Det kan också vara ett verktyg för ett långsiktigt identitetsskapande som skapar en målgruppsgemenskap och ett starkt varumärke. Normbrytning kan även påverka samhället genom att öka acceptans. En oro kring konsekvenserna av normbrytning leder till en försiktighet, både hos byråer och beställare. Risken är att få dålig publicitet och skada varumärket om det görs på del sätt. Det kan också göra kommunikationen otydlig och överskugga företagets produkt. Majoriteten av informanterna finner normbrytande reklam sällan förekommande. De upplever att de yngre generationerna har en större öppenhet och att normbrytning därför är vanligare i reklam riktad till ungdomar.

  • 316.
    Appelgren, Leif
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, EISLAB - Economic Information Systems.
    Audit Strategies for the Taxation of Investment2004Inngår i: Bournemouth Tax Research Network Conference 2004 September 16-17,2004, 2004Konferansepaper (Annet vitenskapelig)
  • 317.
    Aragon, Elena
    et al.
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Jimenez, Juan M.
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Maghazeh, Arian
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    Rasmusson, Jim
    Sony Mobile Communications, Sweden.
    Bordoloi, Unmesh D.
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    Pattern matching in OpenCL: GPU vs CPU energy consumption on two mobile chipsets2014Inngår i: Proceedings of the International Workshop / OpenCL 2013 & 2014 (IWOCL '14), ACM Digital Library, 2014, s. Article No. 5-Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    Adaptations of the Aho-Corasick (AC) algorithm on high performance graphics processors (also called GPUs) have garnered increasing attention in recent years. However, no results have been reported regarding their implementations on mobile GPUs. In this paper, we show that implementing a state-of-the-art Aho-Corasick parallel algorithm on a mobile GPU delivers significant speedups. We study a few implementation optimizations some of which may seem counter-intuitive to standard optimizations for high-end GPUs. More importantly, we focus on measuring the energy consumed by different components of the OpenCL application rather than reporting the aggregate. We show that there are considerable energy savings compared to the CPU implementation of the AC algorithm.

  • 318.
    Arbring, Joel
    et al.
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    Hedström, Patrik
    Linköpings universitet, Institutionen för systemteknik, Informationskodning.
    On Data Compression for TDOA Localization2010Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    This master thesis investigates different approaches to data compression on common types of signals in the context of localization by estimating time difference of arrival (TDOA). The thesis includes evaluation of the compression schemes using recorded data, collected as part of the thesis work. This evaluation shows that compression is possible while preserving localization accuracy.

    The recorded data is backed up with more extensive simulations using a free space propagation model without attenuation. The signals investigated are flat spectrum signals, signals using phase-shift keying and single side band speech signals. Signals with low bandwidth are given precedence over high bandwidth signals, since they require more data in order to get an accurate localization estimate.

    The compression methods used are transform based schemes. The transforms utilized are the Karhunen-Loéve transform and the discrete Fourier transform. Different approaches for quantization of the transform components are examined, one of them being zonal sampling.

    Localization is performed in the Fourier domain by calculating the steered response power from the cross-spectral density matrix. The simulations are performed in Matlab using three recording nodes in a symmetrical geometry.

    The performance of localization accuracy is compared with the Cramér-Rao bound for flat spectrum signals using the standard deviation of the localization error from the compressed signals.

  • 319.
    Ardi, Shanai
    Linköpings universitet, Institutionen för datavetenskap, IISLAB - Laboratoriet för intelligenta informationssystem. Linköpings universitet, Tekniska högskolan.
    A Model and Implementation of a Security plug-in for the Software Life Cycle2008Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Currently, security is frequently considered late in software life cycle. It is often bolted on late in development, or even during deployment or maintenance, through activities such as add-on security software and penetration-and-patch maintenance. Even if software developers aim to incorporate security into their products from the beginning of the software life cycle, they face an exhaustive amount of ad hoc unstructured information without any practical guidance on how and why this information should be used and what the costs and benefits of using it are. This is due to a lack of structured methods.

    In this thesis we present a model for secure software development and implementation of a security plug-in that deploys this model in software life cycle. The model is a structured unified process, named S3P (Sustainable Software Security Process) and is designed to be easily adaptable to any software development process. S3P provides the formalism required to identify the causes of vulnerabilities and the mitigation techniques that address these causes to prevent vulnerabilities. We present a prototype of the security plug-in implemented for the OpenUP/Basic development process in Eclipse Process Framework. We also present the results of the evaluation of this plug-in. The work in this thesis is a first step towards a general framework for introducing security into the software life cycle and to support software process improvements to prevent recurrence of software vulnerabilities.

  • 320.
    Ardi, Shanai
    Linköpings universitet, Institutionen för datavetenskap.
    A Nonlinear Programming Approach for Dynamic Voltage Scaling2005Independent thesis Basic level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [en]

    Embedded computing systems in portable devices need to be energy efficient, yet they have to deliver adequate performance to the often computationally expensive applications. Dynamic voltage scaling is a technique that offers a speed versus power trade-off, allowing the application to achieve considerable energy savings and, at the same time, to meet the imposed time constraints.

    In this thesis, we explore the possibility of using optimal voltage scaling algorithms based on nonlinear programming at the system level, for a complex multiprocessor scheduling problem. We present an optimization approach to the modeled nonlinear programming formulation of the continuous voltage selection problem excluding the consideration of transition overheads. Our approach achieves the same optimal results as the previous work using the same model, but due to its speed, can be efficiently used for design space exploration. We validate our results using numerous automatically generated benchmarks.

  • 321.
    Ardi, Shanai
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Byers, David
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Meland, Per Håkon
    SINTEF ICT, Trondheim, Norway.
    Tøndel, Inger Anne
    SINTEF ICT, Trondheim, Norway.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    How can the developer benefit from security modeling?2007Inngår i: Second International Conference on Availability, Reliability and Security, 2007, IEEE Computer Society, 2007, s. 1017-1025Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Security has become a necessary part of nearly every software development project, as the overall risk from malicious users is constantly increasing, due to increased consequences of failure, security threats and exposure to threats. There are few projects today where software security can be ignored. Despite this, security is still rarely taken into account throughout the entire software lifecycle; security is often an afterthought, bolted on late in development, with little thought to what threats and exposures exist. Little thought is given to maintaining security in the face of evolving threats and exposures. Software developers are usually not security experts. However, there are methods and tools available today that can help developers build more secure software. Security modeling, modeling of e.g., threats and vulnerabilities, is one such method that, when integrated in the software development process, can help developers prevent security problems in software. We discuss these issues, and present how modeling tools, vulnerability repositories and development tools can be connected to provide support for secure software development

  • 322.
    Ardi, Shanai
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Byers, David
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Towards a Structured Unified Process for Software Security2006Inngår i: ICSE Workshop on Software Engineering for Secure Systems,2006, ACM , 2006, s. 3-10Konferansepaper (Fagfellevurdert)
  • 323.
    Ardi, Shanai
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    A post-mortem incident modeling method2009Inngår i: 2009 International Conference on Availability, Reliability and Security (ARES),  Vol. 1-2, IEEE , 2009, s. 1018-1023Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Incident post-mortem analysis after recovery from incidents is recommended by most incident response experts. An analysis of why and how an incident happened is crucial for determining appropriate countermeasures to prevent the recurrence of the incident. Currently, there is a lack of structured methods for such an analysis, which would identify the causes of a security incident. In this paper, we present a structured method to perform the post-mortem analysis and to model the causes of an incident visually in a graph structure. This method is an extension of our earlier work on modeling software vulnerabilities. The goal of modeling incidents is to develop an understanding of what could have caused the security incident and how its recurrence can be prevented in the future. The method presented in this paper is intended to be used during the post-mortem analysis of incidents by incident response teams.

  • 324.
    Ardi, Shanai
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Integrating a security plug-in with the OpenUP/Basic development process2008Inngår i: Third International Conference on Availability, Reliability and Security, 2008, IEEE Computer Society, 2008, s. 284-291Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we present a security plug-in for the OpenUP/Basic development process. Our security plug-in is based on a structured unified process for secure software development, named S3P (sustainable software security process). This process provides the formalism required to identify the causes of vulnerabilities and the mitigation techniques that prevent these vulnerabilities. We also present the results of an expert evaluation of the security plug-in. The lessons learned from development of the plug-in and the results of the evaluation will be used when adapting S3P to other software development processes.

  • 325.
    Ardi, Shanai
    et al.
    Linköpings universitet, Tekniska högskolan. Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.
    Shahmehri, Nahid
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Introducing Vulnerability Awareness to Common Criteria's Security Targets2009Inngår i: The Fourth International Conference on Software Engineering Advances, Portugal, IEEE Computer Society , 2009, s. 419-424Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Security of software systems has become one of the biggest concerns in our everyday life, since software systems are increasingly used by individuals, companies and governments. One way to help software system consumers gain assurance about the security measures of software products is to evaluate and certify these products with standard evaluation processes. The Common Criteria (ISO/IEC 15408) evaluation scheme is a standard that is widely used by software vendors. This process does not include information about already known vulnerabilities, their attack data and lessons learned from them. This has resulted in criticisms concerning the accuracy of this evaluation scheme since it might not address the areas in which actual vulnerabilities might occur.

    In this paper, we present a methodology that introduces information about threats from vulnerabilities to Common Criteria documents. Our methodology improves the accuracy of the Common Criteria by providing information about known vulnerabilities in Common Criteria’s security target. Our methodology also provides documentation about how to fulfill certain security requirements, which can reduce the time for evaluation of the products.

     

  • 326.
    Arding, Petter
    et al.
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Hedelin, Hugo
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Computer virus: design and detection2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    Computer viruses uses a few different techniques, with various intentions, toinfect files. However, what most of them have in common is that they wantto avoid detection by anti-malware software. To not get detected and stay unnoticed,virus creators have developed several methods for this. Anti-malwaresoftware is constantly trying to counter these methods of virus infections withtheir own detection-techniques. In this paper we have analyzed the differenttypes of viruses and their infection techniques, and tried to determined whichworks the best to avoid detection. In the experiments we have done we havesimulated executing the viruses at the same time as an anti-malware softwarewas running. Our conclusion is that metamorphic viruses uses the best methodsto stay unnoticed by anti-malware software’s detection techniques.

  • 327.
    Arenius, Marcus
    Linköpings universitet, Institutionen för datavetenskap.
    Getting the Feeling: “Human Error” in an educational ship-handling simulator2010Independent thesis Advanced level (degree of Master (One Year)), 30 poäng / 45 hpOppgave
    Abstract [en]

    In high-risk environments of seafaring, simulators constitute a widely used tool in preparing nauticalstudents for the challenges to be met in real-life working situations. While the technical developmentof ship bridge simulators continues at a breathtaking pace, little is known on how developments fulfiltheir intended safety critical purpose during actual simulator training exercises.In order to investigate this, a mixed-methods quasi-experimental field study (N =6) was conductedaiming at discerning the systemic causes behind committed human errors and to what extent thesecauses can be related to the technical layout of the simulator in general and a decision supportingdisplay in particular. The nautical students’ performance in terms of committed errors was analysedwhen the decision supporting display was either inactive or active during two different exercisebatches. Drawing upon eye tracking evaluation, interviews and simulator video recordings, systemiccauses leading to human errors were identified. Results indicate that all errors occur under the samekind of (stressful) interaction. Based on this design requirements aiming at promoting resilient crewbehaviour were proposed

  • 328.
    Areström, Erik
    Linköpings universitet, Institutionen för datavetenskap.
    Flow Classification of Encrypted Traffic Streams using Multi-fractal Features2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    The increased usage of encrypted application layer traffic is making it harder for traditional traffic categorization methods like deep packet inspection to function. Without ways of categorizing traffic, network service providers have a hard time optimizing traffic flows, resulting in worse quality of experience for the end user. Recent solutions to this problem typically apply some statistical measurements on network flows and use the resulting values as features in a machine learning model. However, by utilizing recent advances in multi-fractal analysis, multi-fractal features can be extracted from time-series via wavelet leaders, which can be used as features instead. In this thesis, these features are used exclusively, together with support vector machines, to build a model that categorizes encrypted network traffic into six categories that, according to a report, accounts for over 80% of the mobile traffic composition. The resulting model achieved a F1-score of 0.958 on synthetic traffic while only using multi-fractal features, leading to the conclusion that incorporating multi-fractal features in a traffic categorization framework, implemented at a base station, would be beneficial for the categorization score for such a framework.

  • 329.
    Arkin, Esther M
    et al.
    Stony Brook University, USA,.
    Efrat, Alon
    Computer Science, the University of Arizona, USA,.
    Knauer, Christian
    Institute of Computer Science, Universitat Bayreuth, Germany,.
    Mitchell, Joseph SB
    Stony Brook University, USA,.
    Polishchuk, Valentin
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Kommunikations- och transportsystem. Linköpings universitet, Tekniska fakulteten.
    Rote, Günter
    Institute of Computer Science, Freie Universitat Berlin, Germany,.
    Schlipf, Lena
    Institute of Computer Science, Freie Universitat Berlin, Germany,.
    Talvitie, Topi
    Department of Computer Science, University of Finland.
    Shortest path to a segment and quickest visibility queries2016Inngår i: LIPIcs-Leibniz International Proceedings in Informatics, 2016, Vol. 7, s. 77-100Konferansepaper (Fagfellevurdert)
    Abstract [en]

    We show how to preprocess a polygonal domain with a xed starting point s in order to answer eciently the following queries: Given a point q, how should one move from s in order to see q as soon as possible? This query resembles the well-known shortestpath- to-a-point query, except that the latter asks for the fastest way to reach q, instead of seeing it. Our solution methods include a data structure for a di erent generalization of shortest-path-to-a-point queries, which may be of independent interest: to report eciently a shortest path from s to a query segment in the domain.

  • 330.
    Arkstål, Axel
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Lidström, Kristofer
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska högskolan.
    Enkel vägvisning i en komplex miljö - Att hitta rätt på Linköpings Universitetssjukhus2014Independent thesis Basic level (degree of Bachelor), 20 poäng / 30 hpOppgave
    Abstract [en]

    Att hitta rätt i den stora, komplexa miljön på Linköpings Universitetssjukhus är en utmaning. I nuläget finns skyltning och information i miljön men denna fungerar inte på ett tillräckligt bra sätt. Det är så pass bristande att man har guider vid entrén för att vägleda besökare rätt, något som är både opraktiskt och oekonomiskt. Syftet med denna designfallstudie var att utveckla ett wayshowingsystem för besökare på Linköpings Universitetssjukhus kring dess södra entré och i huvudbyggnaden. För att uppfylla syftet genomfördes ett antal kvalitativa intervjuer och observationer i miljön samt insamling av data från tidigare studier som gjorts i ämnet. Det slutliga resultatet är en kravlista för viktiga parametrar att ha i åtanke vid wayshowing på sjukhuset samt en skyltmanual baserad på kravlistan, med en detaljerad grund kring hur ett skyltsystem på sjukhuset ska se ut. Kravlistan ska kunna ligga till grund för all framtida skyltning på sjukhuset och samtliga krav är tänkta att alltid vara uppfyllda vid ny skyltning. Kraven innefattar framför allt att wayshowingen bör baseras på fysiska skyltar, det ska vara enkelt och tydligt att tolka samt att mängden information ska begränsas så mycket det går för att bli enklare att tyda. För att kunna implementera det nya skyltsystemet på hela sjukhuset behöver skyltmanualen kompletteras med detaljplanering för samtliga plan och byggnader, i nuläget är endast plan 9 och 10 i huvudbyggnaden färdiga för direkt implementation.

  • 331.
    Arkstål, Emil
    Linköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system.
    Interactive Analytics and Visualization for Data Driven Calculation of Individualized COPD Risk2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Chronic obstructive pulmonary disease (COPD) is a high mortality disease, second to stroke and ischemic heart disease. This non-curable disease progressively exacerbates, leading to high personal and societal economic impact, reduced quality of life and often death. General treatment plans for COPD risk mistreating the individuals’ condition. To be effective, the treatment should be individualized following the practices of precision medicine. The aim of this thesis was to develop a data driven algorithm and system with visualization to assess individual COPD risk. With MRI body composition profile measurements, it is possible to accurately assess propensity of a multitude of metabolic conditions, such as coronary heart disease and type 2 diabetes.  The algorithm and system has been developed using Wolfram Language and R within the Wolfram Mathematica framework. The algorithm calculates individualized virtual control groups metabolically similar to the patient’s body composition and spirometric profile. Using UK Biobank data, our tool was used to assess patient COPD propensity using an individual-specific virtual control group with AUROC 0.778 (female) and 0.758 (men). Additionally, the tool was used to identify new body composition profiles related to COPD and associated comorbid conditions.

  • 332.
    Arlitt, Martin
    et al.
    HP Labs.
    Carlsson, NiklasLinköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik.Hedge, NidhiTechnicolor.Wierman, AdamCalifornia Institute of Technology.
    ACM SIGMETRICS Performance Evaluation ReviewVolume 40 Issue 3, December 2012.: Special issue on the 2012 GreenMetrics workshop2013Konferanseproceedings (Fagfellevurdert)
  • 333. Arlitt, Martin
    et al.
    Carlsson, NiklasRolia, Jerry
    Proceedings of the Third GreenMetrics '11 Workshop, in conjunction with (and sponsored by) ACM SIGMETRICS.: ACM Performance Evaluation Review (PER), Special Issue on the 2011 GreenMetrics Workshop.  Volume 39, Issue 3, December 2011.2011Konferanseproceedings (Fagfellevurdert)
  • 334.
    Arlitt, Martin
    et al.
    HP Labs; University of Calgary, Canada.
    Carlsson, Niklas
    Linköpings universitet, Institutionen för datavetenskap, Databas och informationsteknik. Linköpings universitet, Tekniska högskolan.
    Williamson, Carey
    University of Calgary, Canada.
    Rolia, Jerry
    HP Labs.
    Passive Crowd-based Monitoring of World Wide Web Infrastructure and its Performance2012Inngår i: Proc. IEEE International Conference on Communications (ICC 2012), IEEE , 2012, s. 2689-2694Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The World Wide Web and the services it provides are continually evolving. Even for a single time instant, it is a complex task to methodologically determine the infrastructure over which these services are provided and the corresponding effect on user perceived performance. For such tasks, researchers typically rely on active measurements or large numbers of volunteer users. In this paper, we consider an alternative approach, which we refer to as passive crowd-based monitoring. More specifically, we use passively collected proxy logs from a global enterprise to observe differences in the quality of service (QoS) experienced by users on different continents. We also show how this technique can measure properties of the underlying infrastructures of different Web content providers. While some of these properties have been observed using active measurements, we are the first to show that many of these properties (such as location of servers) can be obtained using passive measurements of actual user activity. Passive crowd-based monitoring has the advantages that it does not add any overhead on Web infrastructure, it does not require any specific software on the clients, but still captures the performance and infrastructure observed by actual Web usage.

  • 335.
    Arman, Sheikh Ali
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system. Linköpings universitet, Tekniska högskolan.
    RESTful Mobile Application for Android: Mobile Version of Inspectera Online2014Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Web service-based mobile applications have become emergent in the recent years. Representational State Transfer (REST) architecture style introduced the concept of Resource Oriented Architecture (ROA), which has been widely used for building applications for all platforms. This master’s thesis designs and develops a Web service-based mobile application for Android platform following the constraints of REST architectural style. It also proposes an authentication model for RESTful applications. The master’s thesis is completed at the company Inspectera HK AB in Norrköping, Sweden. The developed application is called the “Mobile version of Inspectera Online.” 

  • 336.
    Armengol Llobet, J.
    et al.
    n/a.
    Bregon, A.
    n/a.
    Escobet, E
    n/a.
    Gelso, R.
    n/a.
    Krysander, Mattias
    n/a.
    Nyberg, Mattias
    Linköpings universitet, Institutionen för systemteknik, Fordonssystem. Linköpings universitet, Tekniska högskolan.
    Olive, X.
    n/a.
    Pulido, B.
    n/a.
    Trave-Massuyes, L.
    n/a.
    Minimal Structurally Overdetermined Sets for Residual Generation: A Comparison of Alternative Approaches2009Inngår i: Proceedings of IFAC Safeprocess'09, Barcelona, Spain, 2009, s. 1480-1485Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The issue of residual generation using structural analysis has been studied by several authors. Structural analysis does not permit to generate the analytical expressions of residuals since the model of the system is abstracted by its structure. However, it determines the set of constraints from which residuals can be generated and it provides the computation sequence to be used. This paper presents and compares four recently proposed algorithms that solve this problem.

  • 337.
    Arnell, Mari
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Filosofiska fakulteten.
    Kassa system?: En användarcentrerad designstudie av kassagränssnitt för The Body Shop2013Independent thesis Advanced level (degree of Master (One Year)), 20 poäng / 30 hpOppgave
    Abstract [sv]

    I denna magisteruppsats har kassagränssnittet som används på kosmetikkedjan The Body shop utvärderats med avseende på hur det stödjer säljarna i sitt arbete. Syftet har varit att se vad säljares kognitiva belastning är under deras arbete och att ta fram ett kassagränssnitt som minskar denna. Studien har genomgått tre faser där den första, ”Undersökningen”, syftade till att undersöka vilken typ av kognitiv belastning säljarna utsätts för. Detta studerades genom att säljare intervjuades och observerades under användning av det befintliga kassasystemet. Den kognitiva belastningen bestod främst av information som säljarna skulle komma ihåg och delge till kunder. I butikerna använde säljarna sig av många olika typer av minnestöd vid och runt kassan. Detta ledde till slutsatsen att ett kassasystem som stödjer det här skulle underlätta för dem. Den andra fasen, ”Design”, syftade till att ta fram ett kassasystem som stödjer säljarnas arbete, hur det skulle kunna se ut och vad det borde innehålla. Som grund gjordes en kravställning och designmålsframställning utifrån resultatet från Undersökningen. Fokus låg på att kassasystemet skulle underlätta så mycket som möjligt för säljarna genom att ta bort eller förenkla moment. Två prototyper togs fram och testades av användare under den tredje fasen, ”Utvärdering”. Användartesterna syftade till att se hur väl designförslagen uppfyllde designmålen och särskild vikt lades vid de funktioner som hjälpte säljarna att distribuera minnet. Det kvalitativa resultatet från testerna visade att användarna tyckte mycket om designförslagen och den nya funktionaliteten. Särskild uppskattning visades för de funktioner som hjälpte dem att distribuera minnet, vilket ledde till slutsatsen att sådana funktioner skulle minska den kognitiva belastningen för säljare på The Body Shop.

  • 338.
    Arntén, Linnea
    et al.
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    de Klerk, Paulina
    Linköpings universitet, Institutionen för teknik och naturvetenskap, Medie- och Informationsteknik. Linköpings universitet, Tekniska fakulteten.
    Att döma hunden efter håren: En designstudie i bokomslagets utformning och dess betydelse för högstadiekillars läslust2018Independent thesis Basic level (degree of Bachelor), 10,5 poäng / 16 hpOppgave
    Abstract [en]

    Statistik visar på att unga, framför allt killar, läser allt mindre. Detta kan antas bero på en rad olika faktorer, bland annat de senaste årens teknologiska framsteg. Denna studie ämnar undersöka hur ett omslag inom genren ungdomslitteratur kan utformas för att tilltala högstadiekillar samt hur stor betydelse omslaget har för målgruppens läslust. Utifrån insamlad data från målgruppen och yrkesverksamma inom bokbranschen samt relevanta teorier, har sex olika designförslag tagits fram. Designförslagen baserades på befintliga titlar från 2017. För att kunna uppfylla studiens syfte lät vi målgruppen och personer i närliggande grupper rent demografiskt värdera dessa, såväl som en formgivare på Bonnier Carlsen. Värderingen påvisade att målgruppen anser att det viktigaste med ett bokomslag är att det förmedlar en känsla. Avbildande illustrationer eller fotografier och tilltalande färger verkar spela en central roll för ett bokomslags attraktionskraft hos målgruppen. Typografi har visat sig vara mindre viktigt än motivet, medan helheten är det som verkar vara viktigast. Studien visar även att bokomslag har en stor betydelse för högstadiekillars läslust.

  • 339.
    Aronsson, Peter
    Linköpings universitet, Institutionen för datavetenskap, PELAB. Linköpings universitet, Tekniska högskolan.
    Automatic Parallelization of Equation-Based Simulation Programs2006Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Modern equation-based object-oriented modeling languages which have emerged during the past decades make it easier to build models of large and complex systems. The increasing size and complexity of modeled systems requires high performance execution of the simulation code derived from such models. More efficient compilation and code optimization techniques can help to some extent. However, a number of heavy-duty simulation applications require the use of high performance parallel computers in order to obtain acceptable execution times. Unfortunately, the possible additional performance offered by parallel computer architectures requires the simulation program to be expressed in a way that makes the potential parallelism accessible to the parallel computer. Manual parallelization of computer programs is generally a tedious and error prone process. Therefore, it would be very attractive to achieve automatic parallelization of simulation programs.

    This thesis presents solutions to the research problem of finding practically usable methods for automatic parallelization of simulation codes produced from models in typical equationbased object-oriented languages. The methods have been implemented in a tool to automatically translate models in the Modelica modeling language to parallel codes which can be efficiently executed on parallel computers. The tool has been evaluated on several application models. The research problem includes the problem of how to extract a sufficient amount of parallelism from equations represented in the form of a data dependency graph (task graph), requiring analysis of the code at a level as detailed as individual expressions. Moreover, efficient clustering algorithms for building clusters of tasks from the task graph are also required. One of the major contributions of this thesis work is a new approach for merging fine-grained tasks by using a graph rewrite system. Results from using this method show that it is efficient in merging task graphs, thereby decreasing their size, while still retaining a reasonable amount of parallelism. Moreover, the new task-merging approach is generally applicable to programs which can be represented as static (or almost static) task graphs, not only to code from equation-based models.

    An early prototype called DSBPart was developed to perform parallelization of codes produced by the Dymola tool. The final research prototype is the ModPar tool which is part of the OpenModelica framework. Results from using the DSBpart and ModPar tools show that the amount of parallelism of complex models varies substantially between different application models, and in some cases can produce reasonable speedups. Also, different optimization techniques used on the system of equations from a model affect the amount of parallelism of the model and thus influence how much is gained by parallelization.

  • 340.
    Aronsson, Peter
    Linköpings universitet, Institutionen för datavetenskap, PELAB - Laboratoriet för programmeringsomgivningar. Linköpings universitet, Tekniska högskolan.
    Automatic Parallelization of Simulation Code from Equation Based Simulation Languages2002Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    Modern state-of-the-art equation based object oriented modeling languages such as Modelica have enabled easy modeling of large and complex physical systems. When such complex models are to be simulated, simulation tools typically perform a number of optimizations on the underlying set of equations in the modeled system, with the goal of gaining better simulation performance by decreasing the equation system size and complexity. The tools then typically generate efficient code to obtain fast execution of the simulations. However, with increasing complexity of modeled systems the number of equations and variables are increasing. Therefore, to be able to simulate these large complex systems in an efficient way parallel computing can be exploited.

    This thesis presents the work of building an automatic parallelization tool that produces an efficient parallel version of the simulation code by building a data dependency graph (task graph) from the simulation code and applying efficient scheduling and clustering algorithms on the task graph. Various scheduling and clustering algorithms, adapted for the requirements from this type of simulation code, have been implemented and evaluated. The scheduling and clustering algorithms presented and evaluated can also be used for functional dataflow languages in general, since the algorithms work on a task graph with dataflow edges between nodes.

    Results are given in form of speedup measurements and task graph statistics produced by the tool. The conclusion drawn is that some of the algorithms investigated and adapted in this work give reasonable measured speedup results for some specific Modelica models, e.g. a model of a thermofluid pipe gave a speedup of about 2.5 on 8 processors in a PC-cluster. However, future work lies in finding a good algorithm that works well in general.

  • 341.
    Aronsson, Peter
    et al.
    MathCore Engineering AB, Linköping, Sweden.
    Broman, David
    Linköpings universitet, Institutionen för datavetenskap, PELAB - Laboratoriet för programmeringsomgivningar. Linköpings universitet, Tekniska högskolan.
    Extendable Physical Unit Checking with Understandable Error Reporting2009Inngår i: Proceedings of the 7th International Modelica Conference, Como, Italy, 20-22 September 2009, Linköping: Linköping University Electronic Press, Linköpings universitet , 2009, s. 890-897Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Dimensional analysis and physical unit checking are important tools for helping users to detect and correct mistakes in dynamic mathematical models. To make tools useful in a broad range of domains, it is important to also support other units than the SI standard. For instance, such units are common in biochemical or financial modeling. Furthermore, if two or more units turn out be in conflict after checking, it is vital that the reported unit information is given in an understandable format for the user, e.g., “N.m” should preferably be shown instead of “m2.kg.s-2”, even if they represent the same unit. Presently, there is no standardized solution to handle these problems for Modelica models. The contribution presented in this paper is twofold. Firstly, we propose an extension to the Modelica language that makes it possible for a library designer to define both new base units and derived units within Modelica models and packets. Today this information is implicitly defined in the specification. Secondly, we describe and analyze a solution to the problem of presenting units to users in a more convenient way, based on an algorithm using Mixed Integer Programming (MIP). Both solutions are implemented, tested, and illustrated with several examples.

  • 342.
    Aronsson, Peter
    et al.
    Linköpings universitet, Institutionen för datavetenskap.
    Fritzson, Peter
    Linköpings universitet, Institutionen för datavetenskap.
    Multiprocessor Scheduling of Simulation Code from Modelica Models2002Konferansepaper (Fagfellevurdert)
  • 343.
    Aronsson, Peter
    et al.
    Linköpings universitet, Institutionen för datavetenskap.
    Fritzson, Peter
    Linköpings universitet, Institutionen för datavetenskap.
    Saldamli, Levon
    Linköpings universitet, Institutionen för datavetenskap.
    Bunus, Peter
    Linköpings universitet, Institutionen för datavetenskap.
    Nyström, Kaj
    Linköpings universitet, Institutionen för datavetenskap.
    Meta Programming and Function Overloading in OpenModelica2003Konferansepaper (Fagfellevurdert)
  • 344. Aroyo, Lora
    et al.
    Welty, ChrisAlani, HarithTaylor, JamieBernstein, AbrahamKagal, LalanaNoy, Natasha FridmanBlomqvist, EvaLinköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system. Linköpings universitet, Tekniska högskolan.
    The Semantic Web - ISWC 2011 - 10th International Semantic Web Conference, Bonn, Germany, October 23-27, 2011, Proceedings, Part I2011Konferanseproceedings (Annet vitenskapelig)
  • 345. Aroyo, Lora
    et al.
    Welty, ChrisAlani, HarithTaylor, JamieBernstein, AbrahamKagal, LalanaNoy, Natasha FridmanBlomqvist, EvaLinköpings universitet, Institutionen för datavetenskap, Interaktiva och kognitiva system. Linköpings universitet, Tekniska högskolan.
    The Semantic Web - ISWC 2011 - 10th International Semantic Web Conference, Bonn, Germany, October 23-27, 2011, Proceedings, Part II2011Konferanseproceedings (Annet vitenskapelig)
  • 346.
    Arpteg, Anders
    Linköpings universitet, Institutionen för datavetenskap, KPLAB - Laboratoriet för kunskapsbearbetning. Linköpings universitet, Tekniska högskolan.
    Adaptive Semi-structured Information Extraction2003Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The number of domains and tasks where information extraction tools can be used needs to be increased. One way to reach this goal is to construct user-driven information extraction systems where novice users are able to adapt them to new domains and tasks. To accomplish this goal, the systems need to become more intelligent and able to learn to extract information without need of expert skills or time-consuming work from the user.

    The type of information extraction system that is in focus for this thesis is semistructural information extraction. The term semi-structural refers to documents that not only contain natural language text but also additional structural information. The typical application is information extraction from World Wide Web hypertext documents. By making effective use of not only the link structure but also the structural information within each such document, user-driven extraction systems with high performance can be built.

    The extraction process contains several steps where different types of techniques are used. Examples of such types of techniques are those that take advantage of structural, pure syntactic, linguistic, and semantic information. The first step that is in focus for this thesis is the navigation step that takes advantage of the structural information. It is only one part of a complete extraction system, but it is an important part. The use of reinforcement learning algorithms for the navigation step can make the adaptation of the system to new tasks and domains more user-driven. The advantage of using reinforcement learning techniques is that the extraction agent can efficiently learn from its own experience without need for intensive user interactions.

    An agent-oriented system was designed to evaluate the approach suggested in this thesis. Initial experiments showed that the training of the navigation step and the approach of the system was promising. However, additional components need to be included in the system before it becomes a fully-fledged user-driven system.

  • 347.
    Arpteg, Anders
    Linköpings universitet, Institutionen för datavetenskap. Linköpings universitet, Tekniska högskolan.
    Intelligent semi-structured information extraction: a user-driven approach to information extraction2005Doktoravhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    The number of domains and tasks where information extraction tools can be used needs to be increased. One way to reach this goal is to design user-driven information extraction systems where non-expert users are able to adapt them to new domains and tasks. It is difficult to design general extraction systems that do not require expert skills or a large amount of work from the user. Therefore, it is difficult to increase the number of domains and tasks. A possible alternative is to design user-driven systems, which solve that problem by letting a large number of non-expert users adapt the systems themselves. To accomplish this goal, the systems need to become more intelligent and able to learn to extract with as little given information as possible.

    The type of information extraction system that is in focus for this thesis is semi-structured information extraction. The term semi-structured refers to documents that not only contain natural language text but also additional structural information. The typical application is information extraction from World Wide Web hypertext documents. By making effective use of not only the link structure but also the structural information within each such document, user-driven extraction systems with high performance can be built.

    There are two different approaches presented in this thesis to solve the user-driven extraction problem. The first takes a machine learning approach and tries to solve the problem using a modified $Q(\lambda)$ reinforcement learning algorithm. A problem with the first approach was that it was difficult to handle extraction from the hidden Web. Since the hidden Web is about 500 times larger than the visible Web, it would be very useful to be able to extract information from that part of the Web as well. The second approach is called the hidden observation approach and tries to also solve the problem of extracting from the hidden Web. The goal is to have a user-driven information extraction system that is also able to handle the hidden Web. The second approach uses a large part of the system developed for the first approach, but the additional information that is silently obtained from the user presents other problems and possibilities.

    An agent-oriented system was designed to evaluate the approaches presented in this thesis. A set of experiments was conducted and the results indicate that a user-driven information extraction system is possible and no longer just a concept. However, additional work and research is necessary before a fully-fledged user-driven system can be designed.

  • 348.
    Artchounin, Daniel
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Tuning of machine learning algorithms for automatic bug assignment2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In software development projects, bug triage consists mainly of assigning bug reports to software developers or teams (depending on the project). The partial or total automation of this task would have a positive economic impact on many software projects. This thesis introduces a systematic four-step method to find some of the best configurations of several machine learning algorithms intending to solve the automatic bug assignment problem. These four steps are respectively used to select a combination of pre-processing techniques, a bug report representation, a potential feature selection technique and to tune several classifiers. The aforementioned method has been applied on three software projects: 66 066 bug reports of a proprietary project, 24 450 bug reports of Eclipse JDT and 30 358 bug reports of Mozilla Firefox. 619 configurations have been applied and compared on each of these three projects. In production, using the approach introduced in this work on the bug reports of the proprietary project would have increased the accuracy by up to 16.64 percentage points.

  • 349.
    Artman, Henrik
    et al.
    CSC, KTH.
    Holmlid, Stefan
    Linköpings universitet, Institutionen för datavetenskap, MDI - Interaction and Service Design Research Group. Linköpings universitet, Tekniska högskolan.
    Lantz, Ann
    CSC, KTH.
    Lindquist, Sinna
    CSC, KTH.
    Swartling, Anna
    CSC, KTH.
    Dovhammar, Ulrika
    CSC, KTH.
    Acquisition of usable IT: Acquisition projects to reflect on2009Rapport (Annet vitenskapelig)
    Abstract [en]

    By examining how several organizations have gone through the process of procuring IT systems, we have seen that there is a great need for procurer organizations themselves to understand their role in systems development. What is their responsibility for the outcome of the acquisition process? What is their responsibility for the outcome of the system-in-use? Can they actually take responsibility for the usability of systems? This collection of papers is meant to be a starting point for procurer organizations to reflect on that responsibility, as well as on how they manage the acquisition process. The papers are informed by academic research and grounded in scientific studies, but they are also to be taken as practical efforts to describe the process. We hope they will nurture reflection, and encourage those who are taking a stand to make IT systems usable. Our assumption is that the sooner an organization comes to terms with how the future system will actually be used, the sooner it will be profitable or beneficial.

  • 350.
    Arvid, Johnsson
    Linköpings universitet, Institutionen för datavetenskap, Programvara och system.
    Analysis of GPU accelerated OpenCL applications on the Intel HD 4600 GPU2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    GPU acceleration is the concept of accelerating the execution speed of an application by running it on the GPU. Researchers and developers have always wanted to achieve greater speed for their applications and GPU acceleration is a very common way of doing so. This has been done a long time for highly graphical applications using powerful dedicated GPUs. However, researchers have become more and more interested in using GPU acceleration on everyday applications. Moreover now a days more or less every computer has some sort of integrated GPU which often is underutilized. The integrated GPUs are not as powerful as dedicated ones but they have other benefits such as a lower power consumption and faster data transfer. Therefore this thesis’ purpose was to examine whether the integrated GPU Intel HD 4600 can be used to accelerate the two applications Image Convolution and sparse matrix vector multiplication (SpMV). This was done by analysing the code from a previous thesis which produced some unexpected results as well as a benchmark from the OpenDwarf’s benchmark suite. The Intel HD 4600 was able to speedup both Image Convolution and SpMV by about two times compared to running them on the Intel i7-4790. However, the SpMV implementation was not well suited for the GPU meaning that the speedup was only observed on ideal input configurations.

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