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  • 251.
    Ahlqvist, Oscar
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Åkermark, Wilhelm
    KTH, School of Computer Science and Communication (CSC).
    Examining the Implications of Adding Sentiment Analysis when Clustering based on Party Affiliation through Twitter2017Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Political discussion is very common and a popular statistic for the politically interested are the surveys determining people’s party affiliation. Today they are done manually but it would be beneficial if there was an automated method which could produce the same or similar results. On the social network Twitter there are a lot of users discussing politics, all from political leaders and representatives to just regular people with an interest for the subject. Because of that and also for its convenience when it comes to collecting data, Twitter has been used before in previous work to cluster political users based on what they are discussing. What has not been done before which this thesis contributes is clustering with sentiment analysis. In other terms, trying to cluster people based on what they are discussing but also if their opinion is positive or negative. What was noted in this work was that the part of clustering without sentiment analysis, that had been done in previous studies, was successfully replicated. However adding the sentiment analysis did not give the desired effect and only worsened the results.

  • 252.
    Ahlstedt, Kristoffer
    et al.
    Linköping University, Department of Computer and Information Science.
    Annerwall, Lovisa
    Linköping University, Department of Computer and Information Science.
    Axelsson, Daniel
    Linköping University, Department of Computer and Information Science.
    Björklund, Samuel
    Linköping University, Department of Computer and Information Science.
    Cedenheim, Oliver
    Linköping University, Department of Computer and Information Science.
    Eriksson, Josefin
    Linköping University, Department of Computer and Information Science.
    Lehtonen, Jesper
    Linköping University, Department of Computer and Information Science.
    Lorentzon, Linn
    Linköping University, Department of Computer and Information Science.
    Olofsson, Gustaf
    Linköping University, Department of Computer and Information Science.
    BryggaHem – Development of an E-commerce Web Application with a Usability Focus2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    This thesis is part of a bachelor’s project conducted at Linköping University and addresses the development of an e-commerce web application with a usability focus. A market survey was conducted as part of the project to establish the orientation of the web application. Furthermore, the Scrum methodology is described and analyzed, and the team’s experiences of the project are documented. Research relevant to designing an application with high usability is detailed. Additionally the thesis addresses the tools and frameworks used during the development of the application, as well as ethical aspects of handling user information and selling products related to home-brewing of alcoholic beverages. The conclusion drawn from the project regarding the methodology is that Scrum is a viable methodology for this type of development work, although it requires small teams as well as previous experience of Scrum to yield high efficiency. The conclusion drawn from the project regarding usability is that it is achieved through a combination of variables that to a large extent is based on users’ distinct perceptions of the given application. 

  • 253.
    Ahlström, Catharina
    et al.
    Blekinge Institute of Technology, Department of Human Work Science and Media Technology.
    Fridensköld, Kristina
    Blekinge Institute of Technology, Department of Human Work Science and Media Technology.
    How to support and enhance communication: in a student software development project2002Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    This report, in which we have put an emphasis on the word communication, is based on a student software development project conducted during spring 2002. We describe how the use of design tools plays a key role in supporting communication in group activities and to what extent communication can be supported and enhanced by tools such as mock-ups and metaphors in a group project. We also describe a design progress from initial sketches to a final mock-up of a GUI for a postcard demo application.

  • 254.
    Ahlström, Eric
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Holmqvist, Lucas
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Goswami, Prashant
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Comparing Traditional Key Frame and Hybrid Animation2017In: SCA '17 Proceedings of the ACM SIGGRAPH / Eurographics Symposium on Computer Animation, ACM Digital Library, 2017, nr. a20Conference paper (Refereed)
    Abstract [en]

    In this research the authors explore a hybrid approach which usesthe basic concept of key frame animation together with proceduralanimation to reduce the number of key frames needed for an animationclip. The two approaches are compared by conducting anexperiment where the participating subjects were asked to ratethem based on their visual appeal.

  • 255.
    Ahlström, Martin
    Linköping University, Department of Computer and Information Science.
    User-centred redesign of a business systemusing the Star Life Cycle method2008Independent thesis Advanced level (degree of Master), 20 points / 30 hpStudent thesis
    Abstract [en]

    The purpose with this thesis was to study user activities in a business system, MediusFlow. The overall objective was to identify user related problems and to analyse which of the usability data gathering methods to use in the future development process of the company Medius.

    The outcome of this study indicated that a cognitive related user problem was the most important problem to solve. A Star Life Cycle method was preferred. Two low-fidelity prototypes were developed to exemplify an alternative design solution to the identified cognitive user problem. Furthermore, the two best methods to use when gathering user related requirements were heuristic evaluation and expert review.

    In addition a company specific Style Guide was created with generic guidelines as a foundation for development of future applications within Medius.

  • 256.
    Ahlström, Petter
    Linköping University, Department of Computer and Information Science, EISLAB - Economic Information Systems. Linköping University, The Institute of Technology.
    Affärsstrategier för seniorbostadsmarknaden2005Licentiate thesis, monograph (Other academic)
    Abstract [sv]

    Den demografiska utvecklingen i Sverige går mot en befolkningssammansättning med allt högre medelålder. Enligt svenska befolkningsprognoser kommer nästan var fjärde svensk år 2025 att vara över 65 år. Den äldre andelen av befolkningen utgör en välbeställd grupp med relativt stora realekonomiska tillgångar. Attitydundersökningar på morgondagens pensionärer talar för att denna grupp ställer högre krav på boendeutformning, kringservice, vård och omsorg än tidigare generationer. Flera studier visar på en ökad betalningsvilja och betalningsförmåga för alternativa service- och boendeformer. Samtidigt försöker olika marknadsaktörer att positionera ett produkt- och tjänsteutbud inom en bostadsmarknadens nischer, här definierad som seniorbostadsmarknaden. På seniorbostadsmarknaden har ett särskilt segment identifierats där utöver seniorboende även service-, vård- och omsorgsrelaterade kringtjänster bjuds ut. Mot den bakgrunden har avhandlingens problemställning formulerats enligt följande: vad skapar en stark marknadsposition för en aktör på seniorbostadsmarknaden med integrerad service, vård och omsorg?

    Utgångspunkten har varit ett sannolikt scenario där privata initiativ i allt större utsträckning kommer att bidra till framtida boendelösningar riktade till samhällets seniora och äldrebefolkningsgrupper. Syftet med avhandlingen har varit dels att identifiera de framgångsfaktorer som kan antas ligger till grund för en stark marknadsposition, dels att skapa en typologi över olika affärsstrategier. Genom en branschanalys har det i avhandlingen påvisats att seniorbostadsmarknaden är en nischmarknad med marginell omfattning. Avhandlingens empiriska undersökning har designats som en fältstudie. Fältstudien har i sin tur bl.a. genomförts i form av en förstudie och en intervjustudie. Intervjustudien ägde rum under hösten 2004 med platsbesök och intervjuer av verksamhetsföreträdare för elva utvalda fallstudieorganisationer. Utifrån ett antal i förhand uppställda kriterier har marknadsaktörernas framgångsfaktorer identifierats. Den bearbetnings- och analysmodell som konstruerats för detta syfte och som använts för att analysera fältstudiens empiri är baserad på studier inom strategiområdet. Modellen har bl.a. inspirerats av forskare som Miles & Snow (1978), Porter (1980) och Gupta & Govindarajan (1984). Vidare bygger den på antagandena om resursers och kompetensers betydelse för strategiformuleringen. Service management, och då särskilt tjänsters sammansättning, är ett annat område som beaktas. Analysmodellen har byggts upp kring fem dimensioner: omgivning, strategi, resurser, tjänstekoncept och konkurrens. De identifierade framgångsfaktorerna har baserats på intervjustudiens två mest framgångsrika aktörer. Resultatet har formulerats i ett antal strategiska vägval vilka kan sammanfattas i begreppen: differentiering, fokus, integration, samverkan, kontroll, verksamhetsutveckling, kärnkompetens och resurser. I avhandlingen påvisas att aktörer som bedriver framgångsrik verksamhet på seniorbostadsmarknaden till stora delar följer det Porter (1980) definierat som en differentieringsstrategi med fokus. Avhandlingen har också utmynnat i en affärsstrategisk typologi för seniorbostadsmarknaden. Dessa tentativa slutsatser har formulerats i fyra strategiska idealtyper: förvaltare, konceptbyggare, entreprenörer och idealister.

  • 257.
    Ahlström, Petter
    et al.
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, EISLAB - Economic Information Systems.
    Nilsson, Fredrik
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, EISLAB - Economic Information Systems.
    Affärsstrategier och seniorbostadsmarknaden2005In: Fastighetsnytt, ISSN 1104-8913, Vol. 12 nr 5, 36-37 p.Article in journal (Other (popular science, discussion, etc.))
    Abstract [sv]

      Artikeln beskriver några av resultaten från licentiatavhandlingen "Affärsstrategier för seniorbostadsmarknaden" av Petter Ahlström.      

  • 258.
    Ahltorp, Magnus
    KTH, School of Computer Science and Communication (CSC).
    A Personalizable Reading Aid for Second Language Learners of Japanese.2012Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Magnus Ahltorp

    A Personalizable Reading Aid for Second Language Learners of Japanese

    Second language learners of Japanese today have access to vast amounts of authentic Japanese text, audio and video material. A challenge that the Japanese learner faces though, is that the process of looking up words in a dictionary is prohibitively slow. In this thesis, I describe a personalizable system that helps the user read Japanese text by providing pronunciation information and English explanations at the user's request. I also describe the user-centered development of the system and the results of each iteration of user testing. The resulting system and user testing show that it is feasible to provide an immersive reading experience that both beginners and more advanced language learners can use to take command of a crucial part of their own learning.

  • 259.
    Ahlén, Niclas
    University of Skövde, School of Humanities and Informatics.
    ARAVQ som datareducerare för en klassificeringsuppgift inom datautvinning2004Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [sv]

    Adaptive Resource Allocating Vector Quantizer (ARAVQ) är en teknik för datareducering för mobila robotar. Tekniken har visats framgångsrik i enkla miljöer och det har spekulerats i att den kan fungera som ett generellt datautvinningsverktyg för tidsserier. I rapporten presenteras experiment där ARAVQ används som datareducerare på en artificiell respektive en fysiologisk datamängd inom en datautvinningskontext. Dessa datamängder skiljer sig från tidigare robotikmiljöer i och med att de beskriver objekt med diffusa eller överlappande gränser i indatarymden. Varje datamängd klassificeras efter datareduceringen med hjälp av artificiella neuronnät. Resultatet från experimenten tyder på att klassificering med ARAVQ som datareducerare uppnår ett betydligt lägre resultat än om ARAVQ inte används som datareducerare. Detta antas delvis bero på den låga generaliserbarheten hos de lösningar som skapas av ARAVQ. I diskussionen föreslås att ARAVQ skall kompletteras med en funktion för grannskap, motsvarande den som finns i Self-Organizing Map. Med ett grannskap behålls relationerna mellan de kluster som ARAVQ skapar, vilket antas minska följderna av att en beskrivning hamnar i ett grannkluster

  • 260.
    Ahmad, Azeem
    et al.
    Blekinge Institute of Technology, School of Computing.
    Kolla, Sushma Joseph
    Blekinge Institute of Technology, School of Computing.
    Effective Distribution of Roles and Responsibilities in Global Software Development Teams2012Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Context. Industry is moving from co-located form of development to a distributed development in order to achieve different benefits such as cost reduction, access to skillful labor and around the clock working etc. This transfer requires industry to face different challenges such as communication, coordination and monitoring problems. Risk of project failure can be increased, if industry does not address these problems. This thesis is about providing the solutions of these problems in term of effective roles and responsibilities that may have positive impact on GSD team. Objectives. In this study we have developed framework for suggesting roles and responsibilities for GSD team. This framework consists of problems and casual dependencies between them which are related to team’s ineffectiveness, then suggestions in terms of roles and responsibilities have been presented in order to have an effective team in GSD. This framework, further, has been validated in industry through a survey that determines which are the effective roles and responsibilities in GSD. Methods. We have two research methods in this study 1) systematic literature review and 2) survey. Complete protocol for planning, conducting and reporting the review as well as survey has been described in their respective sections in this thesis. A systematic review is used to develop the framework whereas survey is used for framework validation. We have done static validation of framework. Results. Through SLR, we have identified 30 problems, 33 chains of problems. We have identified 4 different roles and 40 different responsibilities to address these chains of problems. During the validation of the framework, we have validated the links between suggested roles and responsibilities and chains of problems. Addition to this, through survey, we have identified 20 suggestions that represents strong positive impact on chains of problems in GSD in relation to team’s effectiveness. Conclusions. We conclude that implementation of effective roles and responsibilities in GSD team to avoid different problems require considerable attention from researchers and practitioners which can guarantee team’s effectiveness. Implementation of proper roles and responsibilities has been mentioned as one of the successful strategies for increasing team’s effectiveness in the literature, but which particular roles and responsibilities should be implemented still need to be addressed. We also conclude that there must be basic responsibilities associated with any particular role. Moreover, we conclude that there is a need for further development and empirical validation of different frameworks for suggesting roles and responsibilities in full scale industry trials.

  • 261.
    Ahmad, Farooq
    et al.
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Lindgren, Helena
    Umeå University, Faculty of Science and Technology, Department of Computing Science.
    Selection of foundational ontology for collaborative knowledge modeling in healthcare domain2010In: Artificial intelligence: methodology, systems, and applications / [ed] Dicheva, Darina; Dochev, Danail, Springer Berlin/Heidelberg, 2010, 261-262 p.Conference paper (Refereed)
    Abstract [en]

    Ontology design is an important process for structuring knowledge to be reused in different projects in the health domain. In this paper, we describe an ontology design for the collaborative knowledge building system ACKTUS to be used for developing personalized knowledge applications for different domains. Different foundational ontologies were compared with respect to selected criteria considered vital for the project, such as modularity and descriptiveness.

  • 262.
    Ahmad, Khurram
    et al.
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Azeem, Muhammad
    Växjö University, Faculty of Mathematics/Science/Technology, School of Mathematics and Systems Engineering.
    Gold Standard Website2009Independent thesis Advanced level (degree of Master (One Year)), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

     

    The aim of this thesis is to design a web base system which provides functionality of comparison between two java files on the basis of point-to information (P2I). User will upload Java files and analysis of Java files called point-to analysis (P2A). System will store the files in the file system for reference and download in later time. System will extract the information called P2I from P2A and it will store that information in the database.

    Database should be flexible to accommodate the changes in P2A file and system should be able to extract the P2I and store it in database with minimum support of system administrator.

     

  • 263.
    AHMAD, MUHAMMAD ZEESHAN
    Blekinge Institute of Technology, School of Engineering.
    Comparative Analysis of Iptables and Shorewall2012Student thesis
    Abstract [en]

    The use of internet has increased over the past years. Many users may not have good intentions. Some people use the internet to gain access to the unauthorized information. Although absolute security of information is not possible for any network connected to the Internet however, firewalls make an important contribution to the network security. A firewall is a barrier placed between the network and the outside world to prevent the unwanted and potentially damaging intrusion of the network. This thesis compares the performance of Linux packet filtering firewalls, i.e. iptables and shorewall. The firewall performance testing helps in selecting the right firewall as needed. In addition, it highlights the strength and weakness of each firewall. Both firewalls were tested by using the identical parameters. During the experiments, recommended benchmarking methodology for firewall performance testing is taken into account as described in RFC 3511. The comparison process includes experiments which are performed by using different tools. To validate the effectiveness of firewalls, several performance metrics such as throughput, latency, connection establishment and teardown rate, HTTP transfer rate and system resource consumption are used. The experimental results indicate that the performance of Iptables firewall decreases as compared to shorewall in all the aspects taken into account. All the selected metrics show that large numbers of filtering rules have a negative impact on the performance of both firewalls. However, UDP throughput is not affected by the number of filtering rules. The experimental results also indicate that traffic sent with different packet sizes do not affect the performance of firewalls.

  • 264.
    Ahmad, Nadeem
    et al.
    Blekinge Institute of Technology, School of Computing.
    Habib, M. Kashif
    Blekinge Institute of Technology, School of Computing.
    Analysis of Network Security Threats and Vulnerabilities by Development & Implementation of a Security Network Monitoring Solution2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Communication of confidential data over the internet is becoming more frequent every day. Individuals and organizations are sending their confidential data electronically. It is also common that hackers target these networks. In current times, protecting the data, software and hardware from viruses is, now more than ever, a need and not just a concern. What you need to know about networks these days? How security is implemented to ensure a network? How is security managed? In this paper we will try to address the above questions and give an idea of where we are now standing with the security of the network.

  • 265.
    Ahmad, Raheel
    Blekinge Institute of Technology, Department of Software Engineering and Computer Science.
    On the Scalability of Four Multi-Agent Architectures for Load Control Management in Intelligent Networks2003Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    Paralleling the rapid advancement in the network evolution is the need for advanced network traffic management surveillance. The increasing number and variety of services being offered by communication networks has fuelled the demand for optimized load management strategies. The problem of Load Control Management in Intelligent Networks has been studied previously and four Multi-Agent architectures have been proposed. The objective of this thesis is to investigate one of the quality attributes namely, scalability of the four Multi-Agent architectures. The focus of this research would be to resize the network and study the performance of the different architectures in terms of Load Control Management through different scalability attributes. The analysis has been based on experimentation through simulations. It has been revealed through the results that different architectures exhibit different performance behaviors for various scalability attributes at different network sizes. It has been observed that there exists a trade-off in different scalability attributes as the network grows. The factors affecting the network performance at different network settings have been observed. Based on the results from this study it would be easier to design similar networks for optimal performance by controlling the influencing factors and considering the trade-offs involved.

  • 266.
    Ahmad, Rezgar
    KTH, School of Computer Science and Communication (CSC).
    Con curdino – Utökning av tvärflöjtens tonförråd till kvartstoner genom perturbation av tonhålens geometri.2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The thesis describes the development and evaluation of a component ('kurdin') that provides flutists the opportunity to play quarter tones on the regular orchestra flute (Böhm flute). The flutist does not need a new instrument or learn a new playing technique.

    Quarter tones were obtained by reducing the diameter of some of the tone holes. The hole diameter is reduced by using the kurdin which is entered inside the flute. The kurdin consists of two parts which can reduce the diameter of two tone holes at the same time. Flutists can thereby extend the available set of scale notes with two quarter tones without changing the position of the kurdin.

    Systematic measurements of the fundamental frequency of four tones (E4, F^#4, A4 and B4) using an artificially blown flute and different versions of the kurdin showed that the pitch of these tones can be lowered a quarter tone (50 cents) with the same reduced hole diameter. The four quarter tones cover almost all scales called Maqamat in oriental music.

  • 267.
    Ahmad, Rezgar
    KTH, School of Computer Science and Communication (CSC), Speech, Music and Hearing, TMH.
    Con curdino – Utökning av tvärflöjtens tonförråd till kvartstoner genom perturbation av tonhålens geometri.2011Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The thesis describes the development and evaluation of a component ('kurdin') that provides flutists the opportunity to play quarter tones on the regular orchestra flute (Böhm flute). The flutist does not need a new instrument or learn a new playing technique.

    Quarter tones were obtained by reducing the diameter of some of the tone holes. The hole diameter is reduced by using the kurdin which is entered inside the flute. The kurdin consists of two parts which can reduce the diameter of two tone holes at the same time. Flutists can thereby extend the available set of scale notes with two quarter tones without changing the position of the kurdin.

    Systematic measurements of the fundamental frequency of four tones (E4, F^#4, A4 and B4) using an artificially blown flute and different versions of the kurdin showed that the pitch of these tones can be lowered a quarter tone (50 cents) with the same reduced hole diameter. The four quarter tones cover almost all scales called Maqamat in oriental music.

  • 268.
    Ahmad, Waqar
    et al.
    Blekinge Institute of Technology, School of Computing.
    Riaz, Asim
    Blekinge Institute of Technology, School of Computing.
    Predicting Friendship Levels in Online Social Networks2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Abstract Context: Online social networks such as Facebook, Twitter, and MySpace have become the preferred interaction, entertainment and socializing facility on the Internet. However, these social network services also bring privacy issues in more limelight than ever. Several privacy leakage problems are highlighted in the literature with a variety of suggested countermeasures. Most of these measures further add complexity and management overhead for the user. One ignored aspect with the architecture of online social networks is that they do not offer any mechanism to calculate the strength of relationship between individuals. This information is quite useful to identify possible privacy threats. Objectives: In this study, we identify users’ privacy concerns and their satisfaction regarding privacy control measures provided by online social networks. Furthermore, this study explores data mining techniques to predict the levels/intensity of friendship in online social networks. This study also proposes a technique to utilize predicted friendship levels for privacy preservation in a semi-automatic privacy framework. Methods: An online survey is conducted to analyze Facebook users’ concerns as well as their interaction behavior with their good friends. On the basis of survey results, an experiment is performed to justify practical demonstration of data mining phases. Results: We found that users are concerned to save their private data. As a precautionary measure, they restrain to show their private information on Facebook due to privacy leakage fears. Additionally, individuals also perform some actions which they also feel as privacy vulnerability. This study further identifies that the importance of interaction type varies while communication. This research also discovered, “mutual friends” and “profile visits”, the two non-interaction based estimation metrics. Finally, this study also found an excellent performance of J48 and Naïve Bayes algorithms to classify friendship levels. Conclusions: The users are not satisfied with the privacy measures provided by the online social networks. We establish that the online social networks should offer a privacy mechanism which does not require a lot of privacy control effort from the users. This study also concludes that factors such as current status, interaction type need to be considered with the interaction count method in order to improve its performance. Furthermore, data mining classification algorithms are tailor-made for the prediction of friendship levels.

  • 269.
    Ahmed, Adnan
    et al.
    Blekinge Institute of Technology, School of Engineering, Department of Interaction and System Design.
    Hussain, Syed Shahram
    Blekinge Institute of Technology, School of Engineering, Department of Interaction and System Design.
    Meta-Model of Resilient information System2007Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    The role of information systems has become very important in today’s world. It is not only the business organizations who use information systems but the governments also posses’ very critical information systems. The need is to make information systems available at all times under any situation. Information systems must have the capabilities to resist against the dangers to its services,performance & existence, and recover to its normal working state with the available resources in catastrophic situations. The information systems with such a capability can be called resilient information systems. This thesis is written to define resilient information systems, suggest its meta-model and to explain how existing technologies can be utilized for the development of resilient information system.

  • 270.
    Ahmed, Ali
    Linköping University, Department of Computer and Information Science, Human-Centered systems. Linköping University, The Institute of Technology.
    A Systematic Literature Review of "Usability Inspection Methods"2013Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Objective: Usability inspection methods are a class of usability evaluation methods, applied by usability evaluators to assess usability related aspects of different user interfaces. Different usability inspection methods are proposed so far to evaluate user interfaces in a better way. This systematic literature review summarized different usability evaluation methods, with more focus on two widely used inspection methods. The review also summarized the problems with these two methods and probable proposed solution to cope with these problems.

    Method: A systematic review method as described by Kitchenham [3] was followed to carry out this review. The identified problems in the review were structured in a form of questions. The search to find the relevant data that address the identified questions were conducted on the basis of planned search strategies. Papers were selected on the basis of inclusion and exclusion criteria in accordance with the quality checklist; followed by data extraction and synthesis strictly characterized by quality checklist, inclusion and exclusion criteria to attain better results.

    Results and discussion: Despite of its advantages there still exists many weaknesses in Heuristic evaluation (HE) and Cognitive walk-through (CW) methods. Different studies have highlighted different factors that may influence the results. Those factors include number of evaluators, evaluator’s perception and experience, time, environment, cost, indigenous design, the way method applied and acquired software.

    Conclusion: To get better evaluation results, it is best to use different techniques for usability evaluation of single software or optimize existing techniques.

  • 271.
    Ahmed, Iftikhar
    et al.
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Farooq, Muhammad
    Halmstad University, School of Information Science, Computer and Electrical Engineering (IDE).
    Switched Multi-hop Priority Queued Networks-Influence of priority levels on Soft Real-time Performance2010Independent thesis Advanced level (degree of Master (One Year)), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    In the last few years, the number of real-time applications has increased. These applications are sensitive and require the methods to utilize existing network capacity efficiently to meet performance requirements and achieve the maximum throughput to overcome delay, jitter and packet loss. In such cases, when the network needs to support highly interactive traffic like packet-switched voice, the network congestion is an issue that can lead to various problems. If the level of congestion is high enough, the users may not be able to complete their calls and have existing calls dropped or may experience a variety of delays that make it difficult to participate smooth conversation.

    In this paper, we investigate the effect of priority levels on soft real-time performance. We use the priority queues to help us manage the congestion, handle the interactive traffic and improve the over all performance of the system. We consider switched multi-hop network with priority queues. All the switches and end-nodes control the real-time traffic with “Earlier Deadline First” scheduling. The performance of the network is characterized in terms of the average delay, the deadline missing ratio and the throughput.

    We will analyze these parameters with both the bursty traffic and evenly distributed traffic. We will analyze different priority levels and will see how the increase in priority level increases the performance of the soft real-time system.

  • 272.
    Ahmed, Kachkach
    KTH, School of Computer Science and Communication (CSC).
    Analyzing user behavior and sentiment in music streaming services2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    These last years, streaming services (for music, podcasts, TV shows and movies) have been under the spotlight by disrupting traditional media consumption platforms. If the technical implications of streaming huge amounts of data are well researched, much remains to be done to analyze the wealth of data collected by these services and exploit it to its full potential in order to improve them. Using raw data about users’ interactions with the music streaming service Spotify, this thesis focuses on three main concepts: streaming context, user attention and the sequential analysis of user actions. We discuss the importance of each of these aspects and propose different statistical and machine learning techniques to model them. We show how these models can be used to improve streaming services by inferring user sentiment and improving recommender systems, characterizing user sessions, extracting behavioral patterns and providing useful business metrics.

  • 273.
    Ahmed, Laeeq
    et al.
    KTH, School of Computer Science and Communication (CSC), High Performance Computing and Visualization (HPCViz).
    Edlund, Åke
    KTH, School of Computer Science and Communication (CSC), High Performance Computing and Visualization (HPCViz).
    Laure, Erwin
    KTH, School of Computer Science and Communication (CSC), High Performance Computing and Visualization (HPCViz).
    Spjuth, O.
    Using iterative MapReduce for parallel virtual screening2013In: 2013 IEEE 5th International Conference on Cloud Computing Technology and Science (CloudCom), IEEE Computer Society, 2013, 27-32 p.Conference paper (Refereed)
    Abstract [en]

    Virtual Screening is a technique in chemo informatics used for Drug discovery by searching large libraries of molecule structures. Virtual Screening often uses SVM, a supervised machine learning technique used for regression and classification analysis. Virtual screening using SVM not only involves huge datasets, but it is also compute expensive with a complexity that can grow at least up to O(n2). SVM based applications most commonly use MPI, which becomes complex and impractical with large datasets. As an alternative to MPI, MapReduce, and its different implementations, have been successfully used on commodity clusters for analysis of data for problems with very large datasets. Due to the large libraries of molecule structures in virtual screening, it becomes a good candidate for MapReduce. In this paper we present a MapReduce implementation of SVM based virtual screening, using Spark, an iterative MapReduce programming model. We show that our implementation has a good scaling behaviour and opens up the possibility of using huge public cloud infrastructures efficiently for virtual screening.

  • 274.
    Ahmed, Mamun
    Blekinge Institute of Technology, School of Engineering.
    Adaptive Sub band GSC Beam forming using Linear Microphone-Array for Noise Reduction/Speech Enhancement.2012Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    This project presents the description, design and the implementation of a 4-channel microphone array that is an adaptive sub-band generalized side lobe canceller (GSC) beam former uses for video conferencing, hands-free telephony etc, in a noisy environment for speech enhancement as well as noise suppression. The side lobe canceller evaluated with both Least Mean Square (LMS) and Normalized Least Mean Square (NLMS) adaptation. A testing structure is presented; which involves a linear 4-microphone array connected to collect the data. Tests were done using one target signal source and one noise source. In each microphone’s, data were collected via fractional time delay filtering then it is divided into sub-bands and applied GSC to each of the subsequent sub-bands. The overall Signal to Noise Ratio (SNR) improvement is determined from the main signal and noise input and output powers, with signal-only and noise-only as the input to the GSC. The NLMS algorithm significantly improves the speech quality with noise suppression levels up to 13 dB while LMS algorithm is giving up to 10 dB. All of the processing for this thesis is implemented on a computer using MATLAB and validated by considering different SNR measure under various types of blocking matrix, different step sizes, different noise locations and variable SNR with noise.

  • 275.
    Ahmed, Mobyen Uddin
    Mälardalen University, School of Innovation, Design and Engineering.
    A case-based multi-modal clinical system for stress management2010Licentiate thesis, monograph (Other academic)
    Abstract [en]

    A difficult issue in stress management is to use biomedical sensor signal in the diagnosis and treatment of stress. Clinicians often make their diagnosis and decision based on manual inspection of physiological signals such as, ECG, heart rate, finger temperature etc. However, the complexity associated with manual analysis and interpretation of the signals makes it difficult even for experienced clinicians. Today the diagnosis and decision is largely dependent on how experienced the clinician is interpreting the measurements.  A computer-aided decision support system for diagnosis and treatment of stress would enable a more objective and consistent diagnosis and decisions.

    A challenge in the field of medicine is the accuracy of the system, it is essential that the clinician is able to judge the accuracy of the suggested solutions. Case-based reasoning systems for medical applications are increasingly multi-purpose and multi-modal, using a variety of different methods and techniques to meet the challenges of the medical domain. This research work covers the development of an intelligent clinical decision support system for diagnosis, classification and treatment in stress management. The system uses a finger temperature sensor and the variation in the finger temperature is one of the key features in the system. Several artificial intelligence techniques have been investigated to enable a more reliable and efficient diagnosis and treatment of stress such as case-based reasoning, textual information retrieval, rule-based reasoning, and fuzzy logic. Functionalities and the performance of the system have been validated by implementing a research prototype based on close collaboration with an expert in stress. The case base of the implemented system has been initiated with 53 reference cases classified by an experienced clinician. A case study also shows that the system provides results close to a human expert. The experimental results suggest that such a system is valuable both for less experienced clinicians and for experts where the system may function as a second option.

  • 276.
    Ahmed, Mobyen Uddin
    et al.
    Örebro University, School of Science and Technology.
    Banaee, Hadi
    Örebro University, School of Science and Technology.
    Rafael-Palou, Xavier
    Barcelona Digital Technology Centre, Barcelona, Spain.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Intelligent Healthcare Services to Support Health Monitoring of Elderly2015In: INTERNET OF THINGS: USER-CENTRIC IOT, PT I, Springer, 2015, Vol. 150, 178-186 p.Conference paper (Refereed)
    Abstract [en]

    This paper proposed an approach of intelligent healthcare services to support health monitoring of old people through the project named SAAPHO. Here, definition and architecture of the proposed healthcare services are presented considering six different health parameters such as: 1) physical activity, 2) blood pressure, 3) glucose, 4) medication compliance, 5) pulse monitoring and 6) weight monitoring. The outcome of the proposed services is evaluated in a case study where total 201 subjects from Spain and Slovenia are involved for user requirements analysis considering 1) end users, 2) clinicians, and 3) field study analysis perspectives. The result shows the potentiality and competence of the proposed healthcare services for the users.

  • 277.
    Ahmed, Mobyen Uddin
    et al.
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Physical Activity Classification for Elderly based on Pulse Rate2013Conference paper (Refereed)
    Abstract [en]

    Physical activity is one of the key components for elderly in order to be actively ageing. However, it is difficult to differentiate and identify the body movement and actual physical activity using only accelerometer measurement. Therefore, this paper presents an application of case-based retrieval classification scheme to classify the physical activity of elderly based on pulse rate measurements. Here, case-based retrieval approach used the features extracted from both time and frequency domain. The evaluation result shows the best accuracy performance while considering the combination of time and frequency domain features. According to the evaluation result while considering the control measurements, the sensitivity, specificity and overall accuracy are achieved as 95%, 96% and 96% respectively. Considering the test dataset, the system was succeeded to identify 13 physical activities out of 16 i.e. the percentage of the correctness was 81%.

  • 278.
    Ahmed, Mobyen Uddin
    et al.
    Örebro University, School of Science and Technology.
    Loutfi, Amy
    Örebro University, School of Science and Technology.
    Physical activity identification using supervised machine learning and based on pulse rate2013In: International Journal of Advanced Computer Sciences and Applications, ISSN 2158-107X, E-ISSN 2156-5570, Vol. 4, no 7, 210-217 p.Article in journal (Refereed)
    Abstract [en]

    Physical activity is one of the key components for elderly in order to be actively ageing. Pulse rate is a convenient physiological parameter to identify elderly’s physical activity since it increases with activity and decreases with rest. However, analysis and classification of pulse rate is often difficult due to personal variation during activity. This paper proposed a Case-Based Reasoning (CBR) approach to identify physical activity of elderly based on pulse rate. The proposed CBR approach has been compared with the two popular classification techniques, i.e. Support Vector Machine (SVM) and Neural Network (NN). The comparison has been conducted through an empirical experimental study where three experiments with 192 pulse rate measurement data are used. The experiment result shows that the proposed CBR approach outperforms the other two methods. Finally, the CBR approach identifies physical activity of elderly 84% accurately based on pulse rate

  • 279.
    Ahmed, Nisar
    et al.
    Blekinge Institute of Technology, School of Computing.
    Yousaf, Shahid
    Blekinge Institute of Technology, School of Computing.
    For Improved Energy Economy – How Can Extended Smart Metering Be Displayed?2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Context: A District Heating System (DHS) uses a central heating plant to produce and distribute hot water in a community. Such a plant is connected with consumers’ premises to provide them with hot water and space heating facilities. Variations in the consumption of heat energy depend upon different factors like difference in energy prices, living standards, environmental effects and economical conditions etc. These factors can manage intelligently by advanced tools of Information and Communication Technology (ICT) such as smart metering. That is a new and emerging technology; used normally for metering of District Heating (DH), district cooling, electricity and gas. Traditional meters measures overall consumption of energy, in contrast smart meters have the ability to frequently record and transmit energy consumption statistics to both energy providers and consumers by using their communication networks and network management systems. Objectives: First objective of conducted study was providing energy consumption/saving suggestions on smart metering display for accepted consumer behavior, proposed by the energy providers. Our second objective was analysis of financial benefits for the energy provides, which could be expected through better consumer behavior. Third objective was analysis of energy consumption behavior of the residential consumes that how we can support it. Moreover, forth objective of the study was to use extracted suggestions of consumer behaviors to propose Extended Smart Metering Display for improving energy economy. Methods: In this study a background study was conducted to develop basic understanding about District Heat Energy (DHE), smart meters and their existing display, consumer behaviors and its effects on energy consumption. Moreover, interviews were conducted with representatives of smart heat meters’ manufacturer, energy providers and residential consumers. Interviews’ findings enabled us to propose an Extended Smart Metering Display, that satisfies recommendations received from all the interviewees and background study. Further in this study, a workshop was conducted for the evaluation of the proposed Extended Smart Metering Display which involved representatives of smart heat meters’ manufacture and residential energy consumers. DHE providers also contributed in this workshop through their comments in online conversation, for which an evaluation request was sent to member companies of Swedish District Heating Association. Results: Informants in this research have different levels of experiences. Through a systematic procedure we have obtained and analyzed findings from all the informants. To fulfill the energy demands during peak hours, the informants emphasized on providing efficient energy consumption behavior to be displayed on smart heat meters. According to the informants, efficient energy consumption behavior can be presented through energy consumption/saving suggestions on display of smart meters. These suggestions are related to daily life activities like taking bath and shower, cleaning, washing and heating usage. We analyzed that efficient energy consumption behavior recommended by the energy providers can provide financial improvements both for the energy providers and the residential consumers. On the basis of these findings, we proposed Extended Smart Metering Display to present information in simple and interactive way. Furthermore, the proposed Extended Smart Metering Display can also be helpful in measuring consumers’ energy consumption behavior effectively. Conclusions: After obtaining answers of the research questions, we concluded that extension of existing smart heat meters’ display can effectively help the energy providers and the residential consumers to utilize the resources efficiently. That is, it will not only reduce energy bills for the residential consumers, but it will also help the energy provider to save scarce energy and enable them to serve the consumers better in peak hours. After deployment of the proposed Extended Smart Metering Display the energy providers will able to support the consumers’ behavior in a reliable way and the consumers will find/follow the energy consumption/saving guidelines easily.

  • 280.
    Ahmed, Qutub Uddin
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Mujib, Saifullah Bin
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Context Aware Reminder System: Activity Recognition Using Smartphone Accelerometer and Gyroscope Sensors Supporting Context-Based Reminder Systems2014Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Context. Reminder system offers flexibility in daily life activities and assists to be independent. The reminder system not only helps reminding daily life activities, but also serves to a great extent for the people who deal with health care issues. For example, a health supervisor who monitors people with different health related problems like people with disabilities or mild dementia. Traditional reminders which are based on a set of defined activities are not enough to address the necessity in a wider context. To make the reminder more flexible, the user’s current activities or contexts are needed to be considered. To recognize user’s current activity, different types of sensors can be used. These sensors are available in Smartphone which can assist in building a more contextual reminder system. Objectives. To make a reminder context based, it is important to identify the context and also user’s activities are needed to be recognized in a particular moment. Keeping this notion in mind, this research aims to understand the relevant context and activities, identify an effective way to recognize user’s three different activities (drinking, walking and jogging) using Smartphone sensors (accelerometer and gyroscope) and propose a model to use the properties of the identification of the activity recognition. Methods. This research combined a survey and interview with an exploratory Smartphone sensor experiment to recognize user’s activity. An online survey was conducted with 29 participants and interviews were held in cooperation with the Karlskrona Municipality. Four elderly people participated in the interview. For the experiment, three different user activity data were collected using Smartphone sensors and analyzed to identify the pattern for different activities. Moreover, a model is proposed to exploit the properties of the activity pattern. The performance of the proposed model was evaluated using machine learning tool, WEKA. Results. Survey and interviews helped to understand the important activities of daily living which can be considered to design the reminder system, how and when it should be used. For instance, most of the participants in the survey are used to using some sort of reminder system, most of them use a Smartphone, and one of the most important tasks they forget is to take their medicine. These findings helped in experiment. However, from the experiment, different patterns have been observed for three different activities. For walking and jogging, the pattern is discrete. On the other hand, for drinking activity, the pattern is complex and sometimes can overlap with other activities or can get noisy. Conclusions. Survey, interviews and the background study provided a set of evidences fostering reminder system based on users’ activity is essential in daily life. A large number of Smartphone users promoted this research to select a Smartphone based on sensors to identify users’ activity which aims to develop an activity based reminder system. The study was to identify the data pattern by applying some simple mathematical calculations in recorded Smartphone sensors (accelerometer and gyroscope) data. The approach evaluated with 99% accuracy in the experimental data. However, the study concluded by proposing a model to use the properties of the identification of the activities and developing a prototype of a reminder system. This study performed preliminary tests on the model, but there is a need for further empirical validation and verification of the model.

  • 281.
    Ahmed, Rakiv
    et al.
    KTH, School of Computer Science and Communication (CSC).
    Aule, Jonas
    KTH, School of Computer Science and Communication (CSC).
    An Evaluation of the Framework Libgdx when Developing a Game Prototype for Android Devices.2011Independent thesis Advanced level (professional degree), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    An evaluation of the framework Libgdx

    when developing a game prototype for Android devices

    By: Rakiv Ahmed & Jonas Aule

    ABSTRACT

    This paper is about evaluation of the framework Libgdx, regarding 2D game development for the Android platform. Other frameworks are also investigated briefly. The game under development is an original game called Magnificent Marbles and is multi-modal as other games for smartphones. The Background section talks about the Android platform and its related tools along with game examples, also frameworks are introduced here. The main focus of this paper will be on the Implementation section and the actual usage of Libgdx. Methods and results for different development versions of the game will be displayed.

    The Discussion section concludes that Libgdx is a good framework due to its desktop support. Libgdx may not suitable for smaller game projects or when wanting to get started quickly without too much knowledge in other areas, such as OpenGL. Another issue is that one should not solely rely on Libgdx desktop support, but knowledge in other areas is required as well to utilize Libgdx to the fullest. The Appendix section includes different documents for more information about Magnificent Marbles.

  • 282.
    Ahmed, Rehan M.
    et al.
    Örebro University, School of Science and Technology.
    Ananiev, Anani V.
    Örebro University, School of Science and Technology.
    Kalaykov, Ivan
    Örebro University, School of Science and Technology.
    Compliant motion control for safe human robot interaction2009In: Robot motion and control 2009 / [ed] Krzysztof R. Kozłowski, Berlin: Springer , 2009, 265-274 p.Conference paper (Refereed)
    Abstract [en]

    Robots have recently been foreseen to work side by side and share workspace with humans in assisting them in tasks that include physical human-robot (HR) interaction. The physical contact with human tasks under uncertainty has to be performed in a stable and safe manner [6]. However, current industrial robot manipulators are still very far from HR coexisting environments, because of their unreliable safety, rigidity and heavy structure. Besides this, the industrial norms separate the two spaces occupied by a human and a robot by means of physical fence or wall [9]. Therefore, the success of such physical HR interaction is possible if the robot is enabled to handle this interaction in a smart way to prevent injuries and damages.

  • 283.
    Ahmed, Rehan M.
    et al.
    Örebro University, School of Science and Technology.
    Kalaykov, Ivan
    Örebro University, School of Science and Technology.
    Ananiev, Anani
    Örebro University, School of Science and Technology.
    Modeling of magneto rheological fluid actuator enabling safe human-robot interaction2008In: IEEE International Conference on Emerging Technologies and Factory Automation, 2008. ETFA 2008, 2008, 974-979 p.Conference paper (Refereed)
    Abstract [en]

    Impedance control and compliant behavior for safe human-robot physical interaction of industrial robots normally can be achieved by using active compliance control of actuators based on various sensor data. Alternatively, passive devices allow controllable compliance motion but usually are mechanically complex. We present another approach using a novel actuation mechanism based on magneto-rheological fluid (MRF) that incorporates variable stiffness directly into the joints. In this paper, we have investigated and analyzed principle characteristics of MRF actuation mechanism and presented the analytical-model. Then we have developed the static and dynamic model based on experimental test results and have discussed three essential modes of motion needed for human-robot manipulation interactive tasks.

  • 284.
    Ahmed, Sabbir
    Blekinge Institute of Technology, School of Engineering, Department of Signal Processing.
    Performance of Multi-Channel Medium Access Control Protocol incorporating Opportunistic Cooperative Diversity over Rayleigh Fading Channel2006Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    This thesis paper proposes a Medium Access Control (MAC) protocol for wireless networks, termed as CD-MMAC that utilizes multiple channels and incorporates opportunistic cooperative diversity dynamically to improve its performance. The IEEE 802.11b standard protocol allows the use of multiple channels available at the physical layer but its MAC protocol is designed only for a single channel. The proposed protocol utilizes multiple channels by using single interface and incorporates opportunistic cooperative diversity by using cross-layer MAC. The new protocol leverages the multi-rate capability of IEEE 802.11b and allows wireless nodes far away from destination node to transmit at a higher rate by using intermediate nodes as a relays. The protocol improves network throughput and packet delivery ratio significantly and reduces packet delay. The performance improvement is further evaluated by simulation and analysis.

  • 285.
    ahmed, Tanveer
    et al.
    Blekinge Institute of Technology, School of Computing.
    Raju, Madhu Sudhana
    Blekinge Institute of Technology, School of Computing.
    Integrating Exploratory Testing In Software Testing Life Cycle, A Controlled Experiment2012Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Context. Software testing is one of the crucial phases in software development life cycle (SDLC). Among the different manual testing methods in software testing, Exploratory testing (ET) uses no predefined test cases to detect defects. Objectives. The main objective of this study is to test the effectiveness of ET in detecting defects at different software test levels. The objective is achieved by formulating hypotheses, which are later tested for acceptance or rejection. Methods. Methods used in this thesis are literature review and experiment. Literature review is conducted to get in-depth knowledge on the topic of ET and to collect data relevant to ET. Experiment was performed to test hypotheses specific to the three different testing levels : unit , integration and system. Results. The experimental results showed that using ET did not find all the seeded defects at the three levels of unit, integration and system testing. The results were analyzed using statistical tests and interpreted with the help of bar graphs. Conclusions. We conclude that more research is required in generalizing the benefits of ET at different test levels. Particularly, a qualitative study to highlight factors responsible for the success and failure of ET is desirable. Also we encourage a replication of this experiment with subjects having a sound technical and domain knowledge.

  • 286.
    Ahmed, Zaheer
    et al.
    Blekinge Institute of Technology, School of Computing.
    Shahzad, Aamir
    Blekinge Institute of Technology, School of Computing.
    Mobile Robot Navigation using Gaze Contingent Dynamic Interface2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Using eyes as an input modality for different control environments is a great area of interest for enhancing the bandwidth of human machine interaction and providing interaction functions when the use of hands is not possible. Interface design requirements in such implementations are quite different from conventional application areas. Both command-execution and feedback observation tasks may be performed by human eyes simultaneously. In order to control the motion of a mobile robot by operator gaze interaction, gaze contingent regions in the operator interface are used to execute robot movement commands, with different screen areas controlling specific directions. Dwell time is one of the most established techniques to perform an eye-click analogous to a mouse click. But repeated dwell time while switching between gaze-contingent regions and feedback-regions decreases the performance of the application. We have developed a dynamic gaze-contingent interface in which we merge gaze-contingent regions with feedback-regions dynamically. This technique has two advantages: Firstly it improves the overall performance of the system by eliminating repeated dwell time. Secondly it reduces fatigue of the operator by providing a bigger area to fixate in. The operator can monitor feedback with more ease while sending commands at the same time.

  • 287. Ahmed, Zara
    et al.
    Benque, David
    Berezin, Sergey
    Dahl, Anna Caroline E.
    KTH, School of Technology and Health (STH), Centres, Centre for Technology in Medicine and Health, CTMH.
    Fisher, Jasmin
    Hall, Benjamin A.
    Ishtiaq, Samin
    Nanavati, Jay
    Piterman, Nir
    Riechert, Maik
    Skoblov, Nikita
    Bringing LTL Model Checking to Biologists2017In: VMCAI 2017: Verification, Model Checking, and Abstract Interpretation / [ed] Bouajjani, A Monniaux, D, Springer, 2017, Vol. 10145, 1-13 p.Conference paper (Refereed)
    Abstract [en]

    The BioModelAnalyzer (BMA) is a web based tool for the development of discrete models of biological systems. Through a graphical user interface, it allows rapid development of complex models of gene and protein interaction networks and stability analysis without requiring users to be proficient computer programmers. Whilst stability is a useful specification for testing many systems, testing temporal specifications in BMA presently requires the user to perform simulations. Here we describe the LTL module, which includes a graphical and natural language interfaces to testing LTL queries. The graphical interface allows for graphical construction of the queries and presents results visually in keeping with the current style of BMA. The Natural language interface complements the graphical interface by allowing a gentler introduction to formal logic and exposing educational resources.

  • 288.
    Ahmetspahic, Emir
    Linköping University, Department of Computer and Information Science.
    Distributed Computing in Peer-to-peer Networks2004Independent thesis Basic level (professional degree)Student thesis
    Abstract [en]

    Concepts like peer-to-peer networks and distributed computing are not new. They have been available in different forms for a long time. This thesis examines the possibility of merging these concepts. The assumption is that non-centralized peer-to-peer networks can be used for effective sharing of computing resources. While most peer-to-peer systems today concentrate on sharing of data in various forms, this thesis concentrates on sharing of clock cycles instead of files.

  • 289.
    Ahnlund, Josefin
    KTH, School of Computer Science and Communication (CSC), Computer Vision and Active Perception, CVAP.
    Statistical Analysis of Conductor-Musician Interaction: With a Focus on Musical Expression2016Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The kind of interaction occurring between a conductor and musicians while performing a musical piece together is an unique instance of human non-verbal communication. This Musical Production Process (MPP) thus provides an interesting area of research, both from a communication perspective and by its own right. The long term goal of this project is to model the MPP with machine learning methods, for which large amounts of data are required. Since the amount of data available to this master thesis stems from a single recording session (collected at KTH May 2014) a direct modeling of the MPP is unfeasible. As such the thesis can instead be considered as a pilot project which examines pre-requisites for modeling of the MPP. The main aim of the thesis is to investigate how musical expression can be captured in the modeling of the MPP. Two experiments, as well as a theoretical investigation of the MPP, are performed to this end. The first experiment consists of a HMM classification of sound represented by expressive tone parameters extracted by the CUEX algorithm, and labeled by four emotions. This experiment complements the previous classification of conducting gesture in GP-LVM representation performed by Kelly Karipidou on the same data set. The result of the classification implicitly proves that expression has been transferred from conductor to musicians. As the first experiment considers expression over the musical piece as a whole, the second experiment investigates the transfer of expression from conductor to musician on a local level. To this end local representations of the sound and conducting gesture are extracted, the separability of the four emotions are calculated for both representations by use of the Bhattacharyya distance and the results are compared in search for correlation. Some indications of correlation between the representations of sound and gesture are found. The conclusion is nevertheless that the utilized representations of conducting gesture do not capture musical expression to a sufficient extent.

  • 290.
    Ahnstedt, Linda
    et al.
    Blekinge Institute of Technology, Department of Software Engineering and Computer Science.
    Johansson, Susanna
    Blekinge Institute of Technology, Department of Software Engineering and Computer Science.
    Basmobilen2003Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    Dagens mobiltelefoner får fler och fler funktioner, det är inte längre ovanligt om det går att koppla upp sig mot Internet eller ta kort med mobiltelefonen. Men frågan som ställs i detta arbete är om mobiltelefonanvändarna är intresserade av dessa nya funktioner. Finns det de som är intresserade av vad som i detta arbete kallas basmobilen, vars funktioner är följande: telefonsamtal, SMS, telefonbok, samtalslista, alarm och möjligheten att kunna byta ringsignal. Efter en historisk inblick i mobiltelefonens utveckling ges en beskrivning av vad basmobilen motsvarar. Med hjälp av en enkätundersökning, intervjuer och insamlade dagböcker besvaras frågan vad mobiltelefonanvändarna är intresserade av. Resultatet visar att basmobilen inte är ointressant för enkätbesvararna, men det finns även en del som saknar funktioner. Detta tas sedan upp i diskussionsavsnittet, där det även finns ett förslag på hur mobiltelefoner ska byggas upp för att passa en så bred användargrupp som möjligt.

  • 291.
    Ahonen-Jonnarth, Ulla
    et al.
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Odelstad, Jan
    University of Gävle, Faculty of Engineering and Sustainable Development, Department of Industrial Development, IT and Land Management.
    Simulation as a tool for the evaluation of forest management treatments2010In: ESM'2010 - The 2010 European Simulation and Modelling Conference / [ed] Gerrit K. Janssens, Katrien Ramaekers and An Caris, Ghent: EUROSIS-ETI , 2010, 426-433 p.Conference paper (Refereed)
    Abstract [en]

    Cleaning of young forest stands is a multicriteria problem with conflicting goals. This kind of forest management treatment is performed by human beings but it is possible that this work may be performed by artificial agents in the future. The artificial agents need detailed information about how to clean a forest stand and/or what are the goals for cleaning. One problem in development of cleaning rules for artificial cleaning agents is that explicit knowledge about good cleaning results is not detailed. In this paper we present a tool for developing and testing rules and judging evaluation functions for cleaning. We illustrate this tool by presenting examples of some ways to clean forest stands in a computer environment and we present how the cleaning results can be evaluated. In order to obtain material for experiments it is also possible to simulate forest stands using this tool.

  • 292.
    Ahrenberg, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, NLPLAB - Natural Language Processing Laboratory.
    Codified Close Translation as a Standard for MT2005In: Conference of the European Association for Machine Translation,2005, Budapest: EAMT , 2005, 13- p.Conference paper (Refereed)
  • 293.
    Ahrenberg, Lars
    Linköping University, Department of Computer and Information Science, NLPLAB - Natural Language Processing Laboratory. Linköping University, The Institute of Technology.
    LinES: An English-Swedish Parallel Treebank2007In: Proceedings of 16th Nordic Conference of Computational Linguistics Nodalida,2007 / [ed] Joakim Nivre, Heiki-Jaan Kaalep, Kadri Muischnek, Mare Koit, Tartu, Estonia: University of Tartu , 2007, 270-273 p.Conference paper (Refereed)
    Abstract [en]

    This paper presents an English-Swedish Parallel Treebank, LinES, that is currently under development. LinES is intended as a resource for the study of variation in translation of common syntactic constructions from English to Swedish. For this reason, annotation in LinES is syntactically oriented, multi-level, complete and manually reviewed according to guidelines. Another aim of LinES is to support queries made in terms of types of translation shifts.

  • 294.
    Ahrenberg, Lars
    Linköping University, The Institute of Technology. Linköping University, Department of Computer and Information Science, NLPLAB - Natural Language Processing Laboratory.
    Searching Parallel Treebanks for Translation Relations2008In: Resourceful Language Technology: Festschrift in Honor of Anna Sågvall Hein, Uppsala: Acta Universitatis Upsaliensis , 2008, 1, 11-20 p.Chapter in book (Other academic)
    Abstract [en]

    As the first holder of the first chair in computational linguistics in Sweden, Anna Sågvall Hein has played a central role in the development of computational linguistics and language technology both in Sweden and on the international scene. Besides her valuable contributions to research, which include work on machine translation, syntactic parsing, grammar checking, word prediction, and corpus linguistics, she has been instrumental in establishing a national graduate school in language technology as well as an undergraduate program in language technology at Uppsala University. It is with great pleasure that we present her with this Festschrift to honor her lasting contributions to the field and to commemorate her retirement from the chair in computational linguistics at Uppsala University. The contributions to the Festschrift come from Anna’s friends and colleagues around the world and deal with many of the topics that are dear to her heart. A common theme in many of the articles, as well as in Anna’s own scientific work, is the design, development and use of adequate language technology resources, epitomized in the title Resourceful Language Technology.

  • 295.
    Ahrenberg, Lars
    et al.
    Linköping University, Department of Computer and Information Science, NLPLAB - Natural Language Processing Laboratory. Linköping University, The Institute of Technology.
    Andersson, Mikael
    Merkel, Magnus
    Linköping University, Department of Computer and Information Science, NLPLAB - Natural Language Processing Laboratory. Linköping University, The Institute of Technology.
    A System for Incremental and Interactive Word Linking2002In: In Third International Conference on Language Resources and Evaluation (LREC 2002), Las Palmas, 29-31 May 2002., European Language Resources Association (ELRA) , 2002, 485-490 p.Conference paper (Refereed)
    Abstract [en]

    Aligned parallel corpora constitute a critical information resource for a great number of linguistic and technological endeavors. Automatic sentence alignment has reached a level whereby large parallel documents can be fully aligned with the aid of interactive post-editing tools. Word alignment systems have not yet reached the same level of performance, but are good enough to support full word alignment if embedded in an interactive system. In this paper we describe a system for fast and accurate word alignment currently under development at our department, where the user can review and improve the output from an automatic system in an incremental fashion.

  • 296.
    Ahsan, Naveed
    et al.
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Ouacha, Aziz
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Dabrowski, Jerzy
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Samuelsson, Carl
    Swedish Defence Research Agency (FOI), P.O. Box 1165, SE-581 11 Linköping, Sweden.
    Dual Band Tunable LNA for Flexible RF Front End2007In: Proceedings of the IEEE International Bhurban Conference on Applied Sciences & Technology (IBCAST 2007), January 8-11, 2007, Islamabad, Pakistan, IEEE Explore , 2007, 19-22 p.Conference paper (Refereed)
    Abstract [en]

    This paper presents a dual band LNA that can be switched between two bands (2.4 GHz & 5.2 GHz) for IEEE 802.1 la/b/g WLAN applications. The LNA is also tunable within each band and the tuning is incorporated by on-chip varactors. The test chip consists of two fully integrated narrow-band tunable LNAs along with SPDT switch. For power saving one LNA can be switched off. The technology process is 0.2 mum GaAs offered by OMMIC. The LNA can achieve a relatively good performance over the two bands as demonstrated by simulation. With a 3V supply, the LNA has a gain of 26.2 dB at 2.4 GHz and 21.8 dB at 5.2 GHz and the corresponding NF varies between 2.07 dB and 1.84 dB, respectively. The LNA has an IIP3 of -7 dBm at 2.4 GHz and -1.6 dBm at 5.2 GHz.

  • 297.
    Ahsan, Naveed
    et al.
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Ouacha, Aziz
    Linköping University, Department of Electrical Engineering, Electronic Devices. Linköping University, The Institute of Technology.
    Samuelsson, Carl
    Swedish Defence Research Agency (FOI), P.O. Box 1165, SE-581 11 Linköping, Sweden.
    Boman, Tomas
    Swedish Defence Research Agency (FOI), P.O. Box 1165, SE-581 11 Linköping, Sweden.
    Applications of Programmable Microwave Function Array (PROMFA)2007In: Proceedings of the IEEE European Conference on Circuit Theory and Design (ECCTD 2007), August 26-30, 2007, Seville, Spain, IEEE , 2007, 164 -167 p.Conference paper (Refereed)
    Abstract [en]

    This paper describes the use of programmable microwave function array (PROMFA) for different microwave application. The PROMFA concept is based on an array of generic cells, in which a number of different functions can be realized. Each PROMFA cell is a four-port circuit, that can either be programmed independently or collectively according to a specific need. Specifically, the phase shift capability in a single PROMFA cell, useful for a new type of phase shifter design is discussed. The paper also presents the functionality of this new architecture as a beamforming network. As an example case an active corporate feed network and a tunable recursive filter is demonstrated. Simulated and measured results are presented.

  • 298.
    Ahsant, Mehran
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for High Performance Computing, PDC.
    On-demand Restricted Delegation: A Framework for Dynamic, Context-Aware, Least-Privilege Delegation in Grids2009Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    In grids, delegation is a key facility that can be used to authenticate and authorize requests on behalf of disconnected users. In current grid systems,delegation is either performed dynamically, in an unrestricted manner, or by a secure but static method. Unfortunately, the former compromises security and the latter cannot satisfy the requirements of dynamic grid application execution. Therefore, development of a delegation framework that enables a restricted and flexible delegation mechanism becomes increasingly urgent as grids are adopted by new communities and grow in size. The main barriers in development of such a mechanism are the requirements for dynamic execution of grid applications, which make it difficult to anticipate required access rights for completing tasks in advance.

    Another significant architectural requirement in grids is federated security and trust. A considerable barrier to achieving this is cross-organizational authentication and identification. Organizations participating in Virtual Organizations (VOs) may use different security infrastructures that implement different protocols for authentication and identification; thus, there exists a need to provide an architectural mechanism for lightweight, rapid and interoperable translation of security credentials from an original format to a format understandable by recipients.

    This thesis contributes the development of a delegation framework that utilizes a mechanism for determining and acquiring only required rights and credentials for completing a task, when they are needed. This is what we call an on-demand delegation framework that realizes a bottom-up delegation model and provides a just-in-time acquisition of rights for restricted and dynamic delegation.

    In this thesis, we further contribute the development of a credential mapping mechanism using off-the-shelf standards and technologies. This mechanism provides support for an on-the-fly exchange of different types of security credentials used by the security mechanisms of existing grids.

  • 299.
    Ahsant, Mehran
    et al.
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for High Performance Computing, PDC.
    Basney, Jim
    Workflows in Dynamic and Restricted Delegation2009In: 2009 INTERNATIONAL CONFERENCE ON AVAILABILITY, RELIABILITY, AND SECURITY (ARES), New York: IEEE , 2009, 17-24 p.Conference paper (Refereed)
    Abstract [en]

    Delegation is a key facility in dynamic, distributed and collaborative environments like e rids and enables an effective use of a wide range of dynamic applications. Traditional delegation frameworks approach a top-down model of delegation for delegating rights from a superior to a subordinate in advance before a delegate starts off a delegated task. However, a top-down model of delegation cannot meet all the requirements of dynamic execution of distributed applications, as in such environments. required access rights for completing a task cannot easily be anticipated in advance. Delegating fewer rights than required for completing a task may cause the task execution to fail while delegating more rights than needed may threaten abuse by malicious parties. It is therefore reasonable and more robust to utilize a mechanism that allows determining and acquiring only required rights and credentials for completing a task, when they are needed. This is what we call an on-demand delegation framework, which realizes a bottom-up delegation model and provides a just-in-time acquisition of rights for a restricted and dynamic delegation. In this paper we elaborate the concept of bottom-up delegation and describe how an on-demand delegation framework can leverage workflows to meet the requirements of the least privileges principle. We also discuss the vital need for dynamic and adaptive scientific workflows to support an on-demand delegation framework. We present three different models or bottom-up delegation, which cover a wide range or usage scenarios in Grids and dynamic collaborative environments. Using a standard RBAC authorization model and a graph-based workflow model (DAG), we define and analyze a formal model of our proposed bottom-up delegation approach.

  • 300.
    Ahsant, Mehran
    et al.
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for High Performance Computing, PDC.
    Basney, Jim
    Johnsson, Lennart
    KTH, School of Computer Science and Communication (CSC), Centres, Centre for High Performance Computing, PDC.
    Dynamic, Context-Aware, Least-Privilege Grid Delegation2007In: 8th IEEE/ACM International Conference on Grid Computing, New York: IEEE , 2007, 209-216 p.Conference paper (Refereed)
    Abstract [en]

    Performing delegation in large scale, dynamic and distributed environments with large numbers of shared resources is more challenging than inside local administrative domains. In dynamic environments like Grids, on one hand, delegating a restricted set of rights reduces exposure to attack but also limits the flexibility and dynamism of the application; on the other hand, delegating all rights provides maximum flexibility but increases exposure. This issue has not yet been adequately addressed by current Grid security mechanisms and is becoming a very challenging and crucial issue for future Grid development. Therefore, providing an effective delegation mechanism which meets the requirements of the least privilege principle is becoming an essential need. Furthermore, we are witnessing a phenomenal increase in the automation of organizational tasks and decision making, as well as the computerization of information related services, requiring automated delegation mechanisms. In order to meet these requirements we introduce an Active Delegation Framework which extends our previous work on on-demand delegation, making it context-aware. The framework provides a just-in-time, restricted and dynamic delegation mechanism for Grids. In this paper we describe the development of this framework and its implementation and integration with the Globus Toolkit.

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