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  • 251.
    Backlund, Per
    University of Skövde, School of Humanities and Informatics.
    ISD as Knowledge Work: An Analysis of How a Development Method is Used in Practice2005In: Information Systems Development: Advances in Theory, Practice,and Education / [ed] Olegas Vasilecas, Wita Wojtkowski, Jože Zupančič, Albertas Caplinskas, W. Gregory Wojtkowski, Stanisław Wrycza, New York: Springer Science+Business Media B.V., 2005, p. 125-136Conference paper (Refereed)
  • 252.
    Backlund, Per
    University of Skövde, Department of Computer Science.
    Systemutvecklingsmetoder ur ett inlärningsperspektiv1999Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [sv]

    Det går att se på en systemutvecklingsmetod på olika sätt. Dels kan man studera den utifrån dess beståndsdelar, och dels kan man studera de processer i utvecklingsarbetet som leder fram till slutresultatet. I detta examensarbete diskuteras en del av de kognitiva krav som ställs vid inlärning av en systemutvecklingsmetod.

    Inom ramen för en litteraturstudie diskuteras vad som är viktigt att lyfta fram när en systemutvecklingsmetod ska presenteras och vilka inlärningsproblem som finns i samband med detta.

    Rapporten innehåller även en fallstudie där en systemutvecklingsmetod (Enterprise Knowledge Development) presenteras i HTML-format i en så kallad Electronic Guide Book. Examensarbetets bidrag till EGB består i att ge exempel på hur valda delar av EKD kan presenteras i HTML-format.

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  • 253.
    Backlund, Per
    University of Skövde, Department of Computer Science.
    The Use of Patterns in Information System Engineering2001Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    The aims of this dissertation are to investigate the use and usefulness of patterns in Information Systems Engineering and to identify future areas of research. In order to do this there is a need to survey different types of patterns and find a common concept of patterns. A pattern is based on experience found in the real world. A text or a model or a combination of the both can describe the pattern. A pattern is typically described in terms of context, forces, problem, and solution. These can be explicitly expressed or implicitly found in the description of the pattern.

    The types of patterns dealt with are: object-oriented patterns; design patterns, analysis patterns; data model patterns; domain patterns; business patterns; workflow patterns and the deontic pattern. The different types of patterns are presented using the authors' own terminology.

    The patterns described in the survey are classified with respect to different aspects. The intention of this analysis is to form a taxonomy for patterns and to bring order into the vast amount of patterns. This is an important step in order to find out how patterns are used and can be used in Information Systems Engineering. The aspects used in the classification are: level of abstraction; text or model emphasis; product or process emphasis; life cycle stage usage and combinations of these aspects.

    Finally an outline for future areas of research is presented. The areas that have been considered of interest are: patterns and Information Systems Engineering methods; patterns and tools (tool support for patterns); patterns as a pedagogical aid; the extraction and documentation of patterns and patterns and novel applications of information technology. Each future area of research is sketched out.

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  • 254.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Alklind Taylor, Anna-Sofia
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Carlén, Urban
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Lebram, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Toftedahl, Marcus
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Tactical Incident Commander - an Online Training Game for Incident Commander Training2011In: Proceedings of the 5th European Conference on Game Based Learning (ECGBL 2011) / [ed] D. Gouscos, M. Meimaris, Academic Conferences Limited, 2011, p. 9-17Conference paper (Refereed)
    Abstract [en]

    This paper presents an online training game for incident commanders to enact and create incident scenarios. The incident commander is the person in command on site when a rescue team is dispatched to a fire emergency. The challenge we are addressing in this work is to design a game and a game-based training process which can be used to support the change of work practice of fire fighters to become incident commanders (i.e. taking on a new professional role). The incident commander training game consists of two integrated parts: the IT artifact and the usage process. The two are integrated to provide necessary support for incident commander training via distance learning. The game is online and comprises three modules: The scenario player; the scenario creator, and; the log tool. The game and its pedagogical usage procedure are based on the theories of communities of practice and experiential learning. The novelty of this application lies in the combination of pedagogical theory and a specifically designed game. In comparison to other games for accident management training, the possibility for domain experts lacking of game design skills to create scenarios is an essential feature. Furthermore, the underlying fire simulation renders better "replayability" than a strictly branched scenario as the scenario creation is actually more of a process of setting conditions for the scenario than predicting each action of the player.

  • 255.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Alklind Taylor, Anna-Sofia
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Lebram, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Slijper, Angelique
    Skaraborg Hospital, Department of Occupational Therapy and Physiotherapy, Skövde, Sweden.
    Svensson, Karin
    Skaraborg Hospital, Department of Occupational Therapy and Physiotherapy, Skövde, Sweden.
    Poucette, Jesper
    Skaraborg Primary Care, Ågårdsskogens Primary Care Centre, Lidköping, Sweden.
    Stibrant Sunnerhagen, Katharina
    The Sahlgrenska Academy, Institute of Neuroscience and Physiology, Section for Clinical Neuroscience and Rehabilitation, Göteborg, Sweden.
    Games on prescription!: Evaluation of the Elinor console for home-based stroke rehabilitation2013In: Transactions on Edutainment IX / [ed] Zhigeng Pan, Adrian David Cheok, Wolfgang Müller, Fotis Liarokapis, Springer Berlin/Heidelberg, 2013, p. 49-64Chapter in book (Refereed)
    Abstract [en]

    This paper reports the feasibility of Elinor, a game-based system for stroke rehabilitation in the home. The Elinor prototype has been positively evaluated with respect to its usability, user acceptance and motivational factors as well as its rehabilitation effect. This paper reports the findings from the whole project. To summarize the results, we find that game factors can be used to enhance motivation for rehabilitation. We had positive results with respect to many of the rehabilitation measurements employed. For example, the assessment of motor and process skills was positive as were also the self-reported improvements in daily activities. Furthermore, it seems that an increased self-efficacy with respect to the belief that the treatment can have an effect is positive and expected to increase motivation to undergo necessary rehabilitation. The usability and perceived usefulness of the system were also positively evaluated and the subjects expressed a positive attitude towards the system as well as a belief in its usefulness. © 2013 Springer-Verlag Berlin Heidelberg.

  • 256.
    Backlund, Per
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Engström, Henrik
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Berg Marklund, Björn
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Toftedahl, Marcus
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Developing games for non-leisure contexts: Identification of challenges and research gaps2017In: 2017 9th International Conference on Virtual Worlds and Games for Serious Applications (VS-Games): Proceedings / [ed] F. Liarokapis et al., IEEE Computer Society Digital Library, 2017, p. 15-22, article id 8055806Conference paper (Refereed)
    Abstract [en]

    The use of games in non-leisure contexts is referred to as serious games. The tradition of using games for purposes beyond entertainment goes back a long time before digital games. However, with the advent of digital games, serious games development has become an issue of both game design and technology development in various combinations. This paper presents a literature review of what types of topics are studied in the realm of serious games development, and contrasts the results with challenges and problems expressed by a panel of developers and researchers in serious games and gamification to identify research gaps. Our findings indicate a lack of research on the actual usage situations of serious games. It seems that the phase of organizational deployment and use is most often overseen. Furthermore, we identified a lack of client/customer perspective in most research on the development of gamified solutions.

  • 257.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Gustavsson, Martin
    University of Skövde.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Lebram, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Sjörs, Emmy
    University of Skövde.
    SIDH: A Game-Based Architecture for a Training Simulator2009In: International Journal of Computer Games Technology, ISSN 1687-7047, E-ISSN 1687-7055, article id 472672Article in journal (Refereed)
    Abstract [en]

    Game-based simulators, sometimes referred to as "lightweight" simulators, have benefits such as flexible technology and economic feasibility. In this article, we extend the notion of a game-based simulator by introducing multiple screen view and physical interaction. These features are expected to enhance immersion and fidelity. By utilizing these concepts we have constructed a training simulator for breathing apparatus entry. Game hardware and software have been used to produce the application. More important, the application itself is deliberately designed to be a game. Indeed, one important design goal is to create an entertaining and motivating experience combined with learning goals in order to create a serious game. The system has been evaluated in cooperation with the Swedish Rescue Services Agency to see which architectural features contribute to perceived fidelity. The modes of visualization and interaction as well as level design contribute to the usefulness of the system.

  • 258.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics.
    Hammar, Cecilia
    University of Skövde.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics.
    Lebram, Mikael
    University of Skövde, School of Humanities and Informatics.
    Sidh: a Game Based Firefighter Training Simulation2007In: Proceedings of the 11th International Conference Information Visualization (IV '07) / [ed] Ebad Banissi, Remo Aslak Burkhard, Georges Grinstein, Liz Stuart, Theodor G. Wyeld, Gennady Andrienko, Jason Dykes, Mikael Jern, Anthony Faiola, Dennis Groth, Anna Ursyn, Andrew J. Cowell, and Ming Hou, IEEE Computer Society, 2007, p. 899-907Conference paper (Refereed)
    Abstract [en]

    This paper presents Sidh - a game based firefighter training simulator developed in cooperation between the University of Sk¨ovde and the Swedish Rescue Services Agency. Sidh is based on computer game hardware and software solutions but adds a novel interaction model and gameplay specifically developed for the purpose of training firefighters. The simulator environment is a Cave where the player is interacting with the game through a set of sensors. Players move in the virtual world by movements in the physical world and a substantial physical effort is required to accomplish game tasks. Sidh has been used in a feasibility study where 31 firefighter students have been playing the game and the performance of these students as well as their reflections from using the game have been analyzed. Results from this study show that Sidh is a useful complement to traditional training methods and that the subjects give very high grades on the entertainment value of the game which indicate that this form of training may be self-motivating which is an important issue for voluntary, after-hours training.

  • 259.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics.
    Computer Gaming and Driving Education2006In: Proceedings of the 14th International Conference on Computers in Education, ICCE 2006: Pedagogical Design of Educational Games, 2006, p. 9-16Conference paper (Refereed)
    Abstract [en]

    This study investigates the learning effects of playing racing, action, and sports computer games. In particular we focus on traffic school students’ driving behavior. A survey conducted at three driving schools, questioned driving students about their gaming habits. The driving instructors evaluated their students’ driving skills and traffic safety attitudes. The results indicate that experience in computer games can have a positive effect on driving performance. Experienced gamers were ranked significantly higher by their instructors regarding their overall driving skills compared to students with low experience in computer games. However, no evidence was found to indicate that experienced gamers have a worse attitude towards fellow road-users or traffic safety. Experiments conducted in a driving simulator, using a game developed purposely to enhance certain traffic safety variables, reveals that it is possible to provide an entertaining game with serious content. Preliminary results, however, indicate that the version of the game where the explicit game goals are hidden was found to be the most entertaining one. The results of the investigation warrant further review into the development and utilization of computer games for traffic safety and education purposes.

  • 260.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics.
    Lebram, Mikael
    University of Skövde, School of Humanities and Informatics.
    Games and Traffic Safety: an Experimental Study in a Game-Based Simulation Environment2007In: 11th International Conference Information Visualization / [ed] Ebad Banissi, Remo Aslak Burkhard, Georges Grinstein, Liz Stuart, Theodor G Wyeld, Gennady Andrienko, Jason Dykes, Mikael Jern, Anthony Faiola, Dennis Groth, Anna Ursyn, Andrew J. Cowell & Ming Hou, IEEE Computer Society, 2007, p. 908-914, article id 4272086Conference paper (Refereed)
    Abstract [en]

    In this paper we report results from an experimental study of games and traffic safety performed in an advanced gaming environment. During car simulator-sessions we collected data over different traffic safety variables, such as speed, headway distance and lane change behavior, from 70 subjects. The data was analyzed in order to investigate possible individual learning effects and differences between groupings of subjects. The experiment shows clear positive individual learning effects for all traffic safety variables analyzed. Hence we conclude that game based simulations can be used to enhance learning in driving education.

  • 261.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Engström, Henrik
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Johannesson, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Lebram, Mikael
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Virtual Systems Research Centre.
    Games for traffic education: An experimental study of a game-based driving simulator2010In: Journal Simulation & Gaming, ISSN 1046-8781, E-ISSN 1552-826X, Vol. 41, no 2, p. 145-169Article in journal (Refereed)
    Abstract [en]

    In this article, the authors report on the construction and evaluation of a game-based driving simulator using a real car as a joystick. The simulator is constructed from off-the-shelf hardware and the simulation runs on open-source software. The feasibility of the simulator as a learning tool has been experimentally evaluated. Results are reported from an experimental study of games and traffic safety performed in an advanced gaming environment. During car simulator sessions, the authors collected data about different traffic safety variables, such as speed, headway distance, and lane change behavior, from 70 participants. The data were analyzed to investigate possible individual learning effects and differences between groupings of participants. The experiment shows clear, positive, individual learning effects for all traffic safety variables analyzed. The authors also made a qualitative analysis of the participants’ perception of the simulator as a learning tool. From the results, it is concluded that a game-based simulation can be used to enhance learning in driving education.

  • 262.
    Backlund, Per
    et al.
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Humanities and Informatics.
    Heldal, Ilona
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Humanities and Informatics.
    Engström, Henrik
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Humanities and Informatics.
    Johannesson, Mikael
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Humanities and Informatics.
    Lebram, Mikael
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Humanities and Informatics.
    Collaboration Patterns in Mixed Reality Environments for a New Emergency Training Center2013In: Proceedings UKSim-AMSS Seventh European Modelling Symposium on Computer Modelling and Simulation EMS2013, IEEE Computer Society, 2013, p. 483-488Conference paper (Refereed)
    Abstract [en]

    Training actors from public safety agencies (PSA), e.g. emergency medical services, fire departments, police departments involves different technologies and communication and collaboration activities. New technologies promise better support, not only for training, but also for logging relevant information for future analysis and learning. However, choosing the right technologies, defining proper set-ups for the training activities, and identifying premises for long-term use of technical facilities is both difficult and time consuming. Applying earlier lessons from evaluating work in Virtual Environments (VEs) [1], our aim is to develop a better understanding of the impact of new technologies by identifying collaboration patterns influencing training. Collaboration is examined via social, technical, and task related interaction, distinguishable in the different phases of training, from starting an alarm to ending the emergency activities. Our main results illustrate the benefits of (1) building scenarios, and training whole activity chains for certain rescue or other emergency activities, (2) using simulations for better understanding physical places, the task, and (3) distinguishing technical, social and task focused characteristics for factors influencing emergency focused collaboration. Moreover, the results also contribute to understanding the benefits of considering specific simulation technologies when training for emergency and rescue activities.

  • 263.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Hendrix, Maurice
    Serious Games Institute, Coventry University, UK.
    Educational Games: Are They Worth the Effort?2013In: Proceedings of the 5th International Conference on Games and Virtual Worlds for Serious Applications (VS-Games 2013), IEEE conference proceedings, 2013, p. CFP1338G-ART-Conference paper (Refereed)
    Abstract [en]

    Over the last decade educational games have become more and more popular. There are many games specifically designed as educational games, as well as a number of entertainment games that have been successfully used for educational purposes. The EduGameLab project aims to stimulate the use of games in the classroom. This paper presents a meta-analysis of the effectiveness of game-based learning and focuses specifically on empirical evidence on the effectiveness of using games in education in the last decade. Moreover, the study focuses on usage in formalized school contexts, i.e. pre-school, elementary school, secondary school, high school and higher education. As secondary aims we also assess whether there are any clear methodological trends and whether a link could be found between the outcome of empirical studies and the evaluator being a stakeholder in the game development.

  • 264.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics.
    Jonasson, Ingi
    University of Skövde, School of Humanities and Informatics.
    Patterns as a means for managing knowledge in the information systems engineering process2002In: Proceedings of the Baltic Conference, BalticDB&IS 2002, Institute of Cybernetics at Tallin Technical University , 2002, p. 15-26Conference paper (Refereed)
  • 265.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics.
    Lundell, Björn
    University of Skövde, School of Humanities and Informatics.
    Lings, Brian
    University of Skövde, School of Humanities and Informatics.
    Emerging work Practices in a Systems Development Project: Observations On a Distributed Development Project2006In: Proceedings of AIS SIGSAND European Symposium on Systems Analysis and Design: Practice and Research / [ed] Michael Lang, Briony J. Oates, Keng Siau, Galway: Centre for Innovation and Structural Change (CISC), J. E. Cairnes Graduate School of Business & Public Policy, National University of Ireland , 2006, p. 15-27Conference paper (Refereed)
  • 266.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Lundell, Björn
    University of Skövde, School of Humanities and Informatics. University of Skövde, The Informatics Research Centre.
    Scacchi, Walt
    Workshop – Serious Games and Open Source: Practice and Futures2009In: Open Source Ecosystems: Diverse Communities Interacting, Springer, 2009, p. 361-362Conference paper (Refereed)
  • 267.
    Backlund, Per
    et al.
    University of Skövde, School of Humanities and Informatics.
    Wangler, Benkt
    University of Skövde, School of Humanities and Informatics.
    Söderström, Eva
    University of Skövde, School of Humanities and Informatics.
    Toms, Anders
    University of Skövde, School of Humanities and Informatics.
    Åhlfeldt, Rose-Mharie
    University of Skövde, School of Humanities and Informatics.
    Persson, Anne
    University of Skövde, School of Humanities and Informatics.
    Ontology driven business processes integration – a position paper2004In: Proceedings of the CAiSE*04 workshops: Enterprise Modelling and Ontologies for Interoperability, 2004, p. 280-283Conference paper (Other academic)
  • 268.
    Backlöf, Kalle
    University of Skövde, School of Life Sciences.
    GROWTH CONDITIONS AND EXPERIMENTAL SETUP FOR BACTERIAL GROWTH AND THE FADING OF PHENOLPHTHALEIN IN ALKALINE SOLUTION2011Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The whole project consisted of two different parts. The first subproject were running optical density measurements to assist in finding optimal growth conditions and experimental setup for use of E.coli BL21 (DE3) bacteria with the PYCARD gene transformed into them. The transformed bacteria will be used for generating data for modeling. Previous laboratory attempts had problems with timing of the exponential phase when several tests were performed simultaneously. The optimizations of a method for displaying growth include trying out using different medium but also different inoculation ratios between culture and medium to see the effects on growth rate. Results have shown that lysogeny broth together with an inoculation ratio of 1:25 results in rapid absorbance increase in the bacterial growth curves.The second part of the thesis project was to study the kinetics of fading of phenolphthalein in sodium hydroxide solution in order to provide a basis for experiments illustrating this in laboratory environment. Phenolphthalein is used in many different applications such as an active ingredient in some laxatives but the perhaps most common use is as an acid-base indicator of pH. The experiments were performed by mixing alkaline solutions of varying sodium hydroxide concentration together with sodium chloride, then after addition of phenolphthalein to study absorbance variations over time to illustrate the rate law which correlates the rate of color fade to sodium hydroxide concentration. The results have proven that they correspond directly so that increasing the concentration of sodium hydroxide raised the color fading rate just as much in percent.

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  • 269.
    Backman, Arvid
    University of Skövde, School of Informatics.
    Effektivitet hos navigering av autonoma agenter: En jämförelse mellan flödesfält och vägföljning2015Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    I detta arbete undersöks två styrbeteenden som kan användas för att navigera grupper av agenter genom olika spelmiljöer. Teknikerna som arbetet har som syfte att utvärdera är vägföljnings- och flödesfältsbeteende. Arbetets undersökning har som avsikt att jämföra dessa tekniker med avseende på tids- och minneseffektivitet och utvärdera hur dessa tekniker presterar på dessa aspekter i olika gruppstorlekar och miljötyper.

    Resultaten från arbetets utförda tester visade att vägföljningsbeteendet klart är den mest minneseffektiva tekniken medan flödesfältsbeteendet var något mer tidseffektiv. I en slutgiltig diskussion presenteras arbetet ur en samhällelig och etisk synpunkt och även en diskussion över hur framtida forskning inom området kan se ut.

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    Effektivitet hos navigering av autonoma agenter
  • 270.
    Backstrom, Tobias
    et al.
    Uppsala Univ, Dept Neurosci, Physiol Unit, Biomed Ctr BMC, SE-75123 Uppsala, Sweden / Uppsala Univ, Evolutionary Biol Ctr, SE-75236 Uppsala, Sweden .
    Pettersson, Andreas
    Swedish Univ Agr Sci, Dept Food Sci, SE-75007 Uppsala, Sweden.
    Johansson, Viktoria
    University of Skövde, School of Life Sciences.
    Winberg, Svante
    Uppsala Univ, Dept Neurosci, Physiol Unit, Biomed Ctr BMC, SE-75123 Uppsala, Sweden .
    CRF and urotensin I effects on aggression and anxiety-like behavior in rainbow trout2011In: Journal of Experimental Biology, ISSN 0022-0949, E-ISSN 1477-9145, Vol. 214, no 6, p. 907-914Article in journal (Refereed)
    Abstract [en]

    Corticotropin-releasing factor (CRF) is central in the stress response but also modulates several behaviors including anxiety-related behaviors and aggression. In this study, juvenile rainbow trout (Oncorhynchus mykiss) were tested for competitive ability, determined during dyadic fights for dominance, after intracerebroventricular (i.c.v.) administration of CRF, urotensin I (UI), the non-specific CRF antagonist alpha-helical RF(9-41) (ahCRF) or the CRF receptor subtype 1-specific antagonist antalarmin, when paired with a mass-matched con-specific injected with saline. In addition, isolated fish received the same substances. Plasma cortisol and brain monoamines were monitored in all fish. Most fish receiving CRF showed a conspicuous behavior consisting of flaring the opercula, opening the mouth and violent shaking of the head from side to side. When this occurred, the fish immediately forfeited the fight. Similar behavior was observed in most fish receiving UI but no effect on outcome of dyadic fights was noted. This behavior seems similar to non-ambulatory motor activity seen in rats and could be anxiety related. Furthermore, fish receiving CRF at a dose of 1000. ng became subordinate, whereas all other treatments had no effects on the outcome of dyadic fights. In addition, isolated fish receiving ahCRF had lower brain stem concentrations of 5-hydroxyindoleacetic acid, serotonin, 3,4-dihydroxyphenylacetic acid and dopamine. In conclusion, CRF seems to attenuate competitive ability, and both CRF and UI seem to induce anxiety-like behavior.

  • 271.
    Badidi, Elarbi
    et al.
    United Arab Emirates University, Al-Ain, United Arab Emirates.
    Atif, Yacine
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Sheng, Michael Z.
    Macquarie University, New South Wales, Australia .
    Maheswaran, Muthucumaru
    McGill University, Montreal, Canada.
    On Personalized Cloud Service Provisioning for Mobile Users Using Adaptive and Context-Aware Service Composition2018In: Computing, ISSN 0010-485X, E-ISSN 1436-5057, Vol. 101, no 4, p. 291-318Article in journal (Refereed)
    Abstract [en]

    Cloud service providers typically compose their services from a number of elementary services, which are developed in- house or built by third-party providers. Personalization of composite services in mobile environments is an interesting and challenging issue to address, given the opportunity to factor-in diverse user preferences and the plethora of mobile devices at use in multiple contexts. This work proposes a framework to address personalization in mobile cloud-service provisioning. Service personalization and adaptation may be considered at different levels, including the user profile, the mobile device in use, the context of the user and the composition specification. The user’s mobile device and external services are typical sources of context information, used in our proposed algorithm to elicit context-aware services. The selection process is guided by quality-of-context (QoC) criteria that combine cloud-service provider requirements and user preferences. Hence, the paper proposes an integrated framework for enhancing personalized mobile cloud-services, based on a composition approach that adapts context information using a common model of service metadata specification.

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  • 272.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Falkman, Göran
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Helldin, Tove
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Visual Data Analysis2019In: Data science in Practice / [ed] Alan Said, Vicenç Torra, Springer, 2019, p. 133-155Chapter in book (Refereed)
    Abstract [en]

    Data Science offers a set of powerful approaches for making new discoveries from large and complex data sets. It combines aspects of mathematics, statistics, machine learning, etc. to turn vast amounts of data into new insights and knowledge. However, the sole use of automatic data science techniques for large amounts of complex data limits the human user’s possibilities in the discovery process, since the user is estranged from the process of data exploration. This chapter describes the importance of Information Visualization (InfoVis) and visual analytics (VA) within data science and how interactive visualization can be used to support analysis and decision-making, empowering and complementing data science methods. Moreover, we review perceptual and cognitive aspects, together with design and evaluation methodologies for InfoVis and VA.

  • 273.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Havsol, Jesper
    AstraZeneca, Gothenburg, Sweden.
    Karpefors, Martin
    AstraZeneca, Gothenburg, Sweden.
    Karlsson, Alexander
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Mathiason, Gunnar
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Short Text Topic Modeling to Identify Trends on Wearable Bio-sensors in Different Media Types2019In: Proceedings - 6th International Symposium on Computational and Business Intelligence, ISCBI 2018, IEEE Computer Society, 2019, p. 89-93Conference paper (Refereed)
    Abstract [en]

    The technology and techniques for bio-sensors are rapidly evolving. Accordingly, there is significant business interest to identify upcoming technologies and new targets for the near future. Text information from internet reflects much of the recent information and public interests that help to understand the trend of a certain field. Thus, we utilize Dirichlet process topic modeling on different media sources containing short text (e.g., blogs, news) which is able to self-adapt the learned topic space to the data. We share the observations from the domain experts on the results derived from topic modeling on wearable biosensors from multiple media sources over more than eight years. We analyze the topics on wearable devices, forecast and market analysis, and bio-sensing techniques found from our method. 

  • 274.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. University of Skövde .
    Helldin, Tove
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. University of Skövde.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre. University of Skövde.
    Identifying Root Cause and Derived Effects in Causal Relationships2017In: Human Interface and the Management of Information: Information, Knowledge and Interaction Design: 19th International Conference, HCI International 2017, Vancouver, BC, Canada, July 9–14, 2017, Proceedings, Part I / [ed] Sakae Yamamoto, Springer, 2017, p. 22-34Conference paper (Refereed)
    Abstract [en]

    This paper focuses on identifying factors that influence the process of finding a root cause and a derived effect in causal node-link graphs with associated strength and significance depictions. We discuss in detail the factors that seem to be involved in identifying a global cause and effect based on the analysis of the results of an online user study with 44 participants, who used both sequential and non-sequential graph layouts. In summary, the results show that participants show geodesic-path tendencies when selecting causes and derived effects, and that context matters, i.e., participant’s own beliefs, experiences and knowledge might influence graph interpretation.

  • 275.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Helldin, Tove
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Understanding Indirect Causal Relationships in Node-Link Graphs2017In: Computer graphics forum (Print), ISSN 0167-7055, E-ISSN 1467-8659, Vol. 36, no 3, p. 411-421Article in journal (Refereed)
    Abstract [en]

    To find correlations and cause and effect relationships in multivariate data sets is central in many data analysis problems. A common way of representing causal relations among variables is to use node-link diagrams, where nodes depict variables and edges show relationships between them. When performing a causal analysis, analysts may be biased by the position of collected evidences, especially when they are at the top of a list. This is of crucial importance since finding a root cause or a derived effect, and searching for causal chains of inferences are essential analytic tasks when investigating causal relationships. In this paper, we examine whether sequential ordering influences understanding of indirect causal relationships and whether it improves readability of multi-attribute causal diagrams. Moreover, we see how people reason to identify a root cause or a derived effect. The results of our design study show that sequential ordering does not play a crucial role when analyzing causal relationships, but many connections from/to a variable and higher strength/certainty values may influence the process of finding a root cause and a derived effect.

  • 276.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, Informatics Research Environment.
    Helldin, Tove
    University of Skövde, School of Informatics. University of Skövde, Informatics Research Environment.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, Informatics Research Environment. Jönköping University, Department of Computer Science and Informatics, School of Engineering, Jönköping, Sweden.
    Nowaczyk, Slawomir
    University of Halmstad, School of Information Technology, Halmstad, Sweden.
    Bouguelia, Mohamed-Rafik
    University of Halmstad, School of Information Technology, Halmstad, Sweden.
    Falkman, Göran
    University of Skövde, School of Informatics. University of Skövde, Informatics Research Environment.
    Interactive clustering: A comprehensive review2020In: ACM Computing Surveys, ISSN 0360-0300, E-ISSN 1557-7341, Vol. 53, no 1, article id 1Article in journal (Refereed)
    Abstract [en]

    In this survey, 105 papers related to interactive clustering were reviewed according to seven perspectives: (1) on what level is the interaction happening, (2) which interactive operations are involved, (3) how user feedback is incorporated, (4) how interactive clustering is evaluated, (5) which data and (6) which clustering methods have been used, and (7) what outlined challenges there are. This article serves as a comprehensive overview of the field and outlines the state of the art within the area as well as identifies challenges and future research needs.

  • 277.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Karlsson, Alexander
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Mellin, Jonas
    University of Skövde, The Informatics Research Centre. University of Skövde, School of Informatics.
    Ståhl, Niclas
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Torra, Vicenç
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Complex Data Analysis2019In: Data science in Practice / [ed] Alan Said, Vicenç Torra, Springer, 2019, p. 157-169Chapter in book (Refereed)
    Abstract [en]

    Data science applications often need to deal with data that does not fit into the standard entity-attribute-value model. In this chapter we discuss three of these other types of data. We discuss texts, images and graphs. The importance of social media is one of the reason for the interest on graphs as they are a way to represent social networks and, in general, any type of interaction between people. In this chapter we present examples of tools that can be used to extract information and, thus, analyze these three types of data. In particular, we discuss topic modeling using a hierarchical statistical model as a way to extract relevant topics from texts, image analysis using convolutional neural networks, and measures and visual methods to summarize information from graphs.

  • 278.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Ventocilla, Elio
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Helldin, Tove
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Falkman, Göran
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Evaluating Multi-Attributes on Cause and Effect Relationship Visualization2017In: Proceedings of the 12th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP 2017): Volumne 3: IVAPP / [ed] Alexandru Telea, Jose Braz, Lars Linsen, SciTePress, 2017, p. 64-74Conference paper (Refereed)
    Abstract [en]

    This paper presents findings about visual representations of cause and effect relationship's direction, strength, and uncertainty based on an online user study. While previous researches focus on accuracy and few attributes, our empirical user study examines accuracy and the subjective ratings on three different attributes of a cause and effect relationship edge. The cause and effect direction was depicted by arrows and tapered lines; causal strength by hue, width, and a numeric value; and certainty by granularity, brightness, fuzziness, and a numeric value. Our findings point out that both arrows and tapered cues work well to represent causal direction. Depictions with width showed higher conjunct accuracy and were more preferred than that with hue. Depictions with brightness and fuzziness showed higher accuracy and were marked more understandable than granularity. In general, depictions with hue and granularity performed less accurately and were not preferred compared to the ones with numbers or with width and brightness.

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  • 279.
    Bae, Juhee
    et al.
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Ventocilla, Elio
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Riveiro, Maria
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    Torra, Vicenç
    University of Skövde, School of Informatics. University of Skövde, The Informatics Research Centre.
    On the Visualization of Discrete Non-additive Measures2018In: Aggregation Functions in Theory and in Practice AGOP 2017 / [ed] Torra V, Mesiar R, Baets B, Springer, 2018, p. 200-210Conference paper (Refereed)
    Abstract [en]

    Non-additive measures generalize additive measures, and have been utilized in several applications. They are used to represent different types of uncertainty and also to represent importance in data aggregation. As non-additive measures are set functions, the number of values to be considered grows exponentially. This makes difficult their definition but also their interpretation and understanding. In order to support understability, this paper explores the topic of visualizing discrete non-additive measures using node-link diagram representations.

  • 280.
    Bagland, Véronique
    et al.
    Laboratoire de Mathématiques, Université Blaise Pascal, Campus Universitaire des Cézeaux, 63177 Aubière Cedex, France.
    Wennberg, Bengt
    Department of Mathematical Sciences, Chalmers Tekniska Högskola, 412 96 Göteborg, Sweden / Department of Mathematical Sciences, Göteborg University, 412 96 Göteborg, Sweden.
    Wondmagegne, Yosief
    University of Skövde, School of Life Sciences.
    Stationary states for the noncutoff Kac equation with a Gaussian thermostat2007In: Nonlinearity, ISSN 0951-7715, E-ISSN 1361-6544, Vol. 20, no 3, p. 583-604Article in journal (Refereed)
    Abstract [en]

    We study the stationary states of a Kac equation with a Gaussian thermostat in the case of a noncutoff cross section. We investigate the existence, smoothness and uniqueness of the stationary states. The theoretical results are illustrated by some numerical simulations.

  • 281.
    Baker, Erik
    University of Skövde, School of Informatics.
    Evaluating the Necessity of Third-Party Antivirus Software2018Independent thesis Basic level (degree of Bachelor), 15 credits / 22,5 HE creditsStudent thesis
    Abstract [en]

    Some may assume that it is essential to purchase and install antivirus software to protect the underlying layers of an IT infrastructure. However, nowadays the Windows 10 operating system is shipped with a built-in antivirus feature by default. With Microsoft being a large contender in the antivirus market it raises the question if it is necessary to use third-party antivirus software in a Windows 10 environment.

     

    The aim of this research is to determine the necessity of third-party antivirus software by examining the detection capabilities and measuring the performance impact caused by third-party antivirus software, in comparison with the antivirus service that is integrated with the Windows 10 operating system. This was done by measuring the response time of certain user activities to determine how the user-experience is affected differently by using third-party antivirus software. In addition to the effect on performance, the documentation of the tested products was studied to determine if there is value in using non-integrated antivirus software.

     

    The results of the performance benchmarks showed that overall there was a significant performance increase when using third-party antivirus. Additionally, the study showed that some third-party antivirus software offers more ways to detect malicious activities than Windows Defender Antivirus. These two facts put together suggests that using third-party antivirus software in a Windows 10 environment is necessary if there is a desire to increase the efficiency of performing certain user activities and if there is a desire to have more detection capabilities available.

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    EvaluatingTheNecessityOfThird-PartyAntivirusSoftware_ErikBaker
  • 282.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Andersson, Martin
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Metamodel-based prediction of performance metrics for bilevel parameter tuning in MOEAs2016In: 2016 IEEE Congress on Evolutionary Computation (CEC), New York: IEEE, 2016, p. 1909-1916Conference paper (Refereed)
    Abstract [en]

    We consider a bilevel parameter tuning problem where the goal is to maximize the performance of a given multi-objective evolutionary optimizer on a given problem. The search for optimal algorithmic parameters requires the assessment of several sets of parameters, through multiple optimization runs, in order to mitigate the effect of noise that is inherent to evolutionary algorithms. This task is computationally expensive and therefore, in this paper, we propose to use sampling and metamodeling to approximate the performance of the optimizer as a function of its parameters. While such an approach is not unheard of, the choice of the metamodel to be used still remains unclear. The aim of this paper is to empirically compare 11 different metamodeling techniques with respect to their accuracy and training times in predicting two popular multi-objective performance metrics, namely, the hypervolume and the inverted generational distance. For the experiments in this pilot study, NSGA-II is used as the multi-objective optimizer for solving ZDT problems, 1 through 4.

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  • 283.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Aslam, Tehseen
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, East Lansing, USA.
    Generalized higher-level automated innovization with application to inventory management2015In: European Journal of Operational Research, ISSN 0377-2217, E-ISSN 1872-6860, Vol. 243, no 2, p. 480-496Article in journal (Refereed)
    Abstract [en]

    This paper generalizes the automated innovization framework using genetic programming in the context of higher-level innovization. Automated innovization is an unsupervised machine learning technique that can automatically extract significant mathematical relationships from Pareto-optimal solution sets. These resulting relationships describe the conditions for Pareto-optimality for the multi-objective problem under consideration and can be used by scientists and practitioners as thumb rules to understand the problem better and to innovate new problem solving techniques; hence the name innovization (innovation through optimization). Higher-level innovization involves performing automated innovization on multiple Pareto-optimal solution sets obtained by varying one or more problem parameters. The automated innovization framework was recently updated using genetic programming. We extend this generalization to perform higher-level automated innovization and demonstrate the methodology on a standard two-bar bi-objective truss design problem. The procedure is then applied to a classic case of inventory management with multi-objective optimization performed at both system and process levels. The applicability of automated innovization to this area should motivate its use in other avenues of operational research.

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  • 284.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Deb, Kalyanmoy
    BEACON Center for the Study of Evolution in Action, Department of Electrical and Computer Engineering, Michigan State University, USA.
    Metaheuristic Techniques2017In: Decision Sciences: Theory and Practice / [ed] Raghu Nandan Sengupta, Aparna Gupta, Joydeep Dutta, Boca Raton: CRC Press, 2017, p. 693-750Chapter in book (Refereed)
  • 285.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Deb, Kalyanmoy
    Michigan State University, USA.
    Temporal Innovization: Evolution of Design Principles Using Multi-objective Optimization2015In: Proceedings of the 8th International Conference on Evolutionary Multi-Criterion Optimization (EMO 2015), Springer, 2015, Vol. 9018, p. 79-93Conference paper (Refereed)
    Abstract [en]

    Multi-objective optimization yields multiple solutions each of which is no better or worse than the others when the objectives are conflicting. These solutions lie on the Pareto-optimal front which is a lower-dimensional slice of the objective space. Together, the solutions may possess special properties that make them optimal over other feasible solutions. Innovization is the process of extracting such special properties (or design principles) from a trade-off dataset in the form of mathematical relationships between the variables and objective functions. In this paper, we deal with a closely related concept called temporal innovization. While innovization concerns the design principles obtained from the trade-off front, temporal innovization refers to the evolution of these design principles during the optimization process. Our study indicates that not only do different design principles evolve at different rates, but that they start evolving at different times. We illustrate temporal innovization using several examples.

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  • 286.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Gaur, Abhinav
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Khare, Vineet
    Amazon Development Centre (India) Pvt. Ltd., Bengaluru, India.
    Chougule, Rahul
    Department of Mechanical Engineering, Walchand College of Engineering, Sangli, India.
    Bandyopadhyay, Pulak
    General Motors R&D Center, Warren, USA.
    Development, analysis and applications of a quantitative methodology for assessing customer satisfaction using evolutionary optimization2015In: Applied Soft Computing, ISSN 1568-4946, E-ISSN 1872-9681, Vol. 30, p. 265-278Article in journal (Refereed)
    Abstract [en]

    Consumer-oriented companies are getting increasingly more sensitive about customer's perception of their products, not only to get a feedback on their popularity, but also to improve the quality and service through a better understanding of design issues for further development. However, a consumer's perception is often qualitative and is achieved through third party surveys or the company's recording of after-sale feedback through explicit surveys or warranty based commitments. In this paper, we consider an automobile company's warranty records for different vehicle models and suggest a data mining procedure to assign a customer satisfaction index (CSI) to each vehicle model based on the perceived notion of the level of satisfaction of customers. Based on the developed CSI function, customers are then divided into satisfied and dissatisfied customer groups. The warranty data are then clustered separately for each group and analyzed to find possible causes (field failures) and their relative effects on customer's satisfaction (or dissatisfaction) for a vehicle model. Finally, speculative introspection has been made to identify the amount of improvement in CSI that can be achieved by the reduction of some critical field failures through better design practices. Thus, this paper shows how warranty data from customers can be utilized to have a better perception of ranking of a product compared to its competitors in the market and also to identify possible causes for making some customers dissatisfied and eventually to help percolate these issues at the design level. This closes the design cycle loop in which after a design is converted into a product, its perceived level of satisfaction by customers can also provide valuable information to help make the design better in an iterative manner. The proposed methodology is generic and novel, and can be applied to other consumer products as well.

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  • 287.
    Bandaru, Sunith
    et al.
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Ng, Amos
    University of Skövde, The Virtual Systems Research Centre. University of Skövde, School of Engineering Science.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, East Lansing, USA.
    On the Performance of Classification Algorithms for Learning Pareto-Dominance Relations2014In: Proceedings of the 2014 IEEE Congress on Evolutionary Computation (CEC), IEEE Press, 2014, p. 1139-1146Conference paper (Refereed)
    Abstract [en]

    Multi-objective evolutionary algorithms (MOEAs)are often criticized for their high-computational costs. Thisbecomes especially relevant in simulation-based optimizationwhere the objectives lack a closed form and are expensive toevaluate. Over the years, meta-modeling or surrogate modelingtechniques have been used to build inexpensive approximationsof the objective functions which reduce the overall number offunction evaluations (simulations). Some recent studies however,have pointed out that accurate models of the objective functionsmay not be required at all since evolutionary algorithms onlyrely on the relative ranking of candidate solutions. Extendingthis notion to MOEAs, algorithms which can ‘learn’ Paretodominancerelations can be used to compare candidate solutionsunder multiple objectives. With this goal in mind, in thispaper, we study the performance of ten different off-the-shelfclassification algorithms for learning Pareto-dominance relationsin the ZDT test suite of benchmark problems. We considerprediction accuracy and training time as performance measureswith respect to dimensionality and skewness of the training data.Being a preliminary study, this paper does not include results ofintegrating the classifiers into the search process of MOEAs.

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    bandaru2014performance
  • 288.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    An empirical comparison of metamodeling strategies in noisy environments2018In: Proceedings of the Genetic and Evolutionary Computation Conference (GECCO-2018) / [ed] Hernan Aguirre, New York, NY, USA: ACM Digital Library, 2018, p. 817-824, article id 3205509Conference paper (Refereed)
    Abstract [en]

    Metamodeling plays an important role in simulation-based optimization by providing computationally inexpensive approximations for the objective and constraint functions. Additionally metamodeling can also serve to filter noise, which is inherent in many simulation problems causing optimization algorithms to be mislead. In this paper, we conduct a thorough statistical comparison of four popular metamodeling methods with respect to their approximation accuracy at various levels of noise. We use six scalable benchmark problems from the optimization literature as our test suite. The problems have been chosen to represent different types of fitness landscapes, namely, bowl-shaped, valley-shaped, steep ridges and multi-modal, all of which can significantly influence the impact of noise. Each metamodeling technique is used in combination with four different noise handling techniques that are commonly employed by practitioners in the field of simulation-based optimization. The goal is to identify the metamodeling strategy, i.e. a combination of metamodeling and noise handling, that performs significantly better than others on the fitness landscapes under consideration. We also demonstrate how these results carry over to a simulation-based optimization problem concerning a scalable discrete event model of a simple but realistic production line.

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    fulltext
  • 289.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Trend Mining: A Visualization Technique to Discover Variable Trends in the Objective Space2019In: Evolutionary Multi-Criterion Optimization: 10th International Conference, EMO 2019, East Lansing, MI, USA, March 10-13, 2019, Proceedings / [ed] Kalyanmoy Deb, Erik Goodman, Carlos A. Coello Coello, Kathrin Klamroth, Kaisa Miettinen, Sanaz Mostaghim, Patrick Reed, Cham, Switzerland: Springer, 2019, Vol. 11411, p. 605-617Conference paper (Refereed)
    Abstract [en]

    Practical multi-objective optimization problems often involve several decision variables that influence the objective space in different ways. All variables may not be equally important in determining the trade-offs of the problem. Decision makers, who are usually only concerned with the objective space, have a hard time identifying such important variables and understanding how the variables impact their decisions and vice versa. Several graphical methods exist in the MCDM literature that can aid decision makers in visualizing and navigating high-dimensional objective spaces. However, visualization methods that can specifically reveal the relationship between decision and objective space have not been developed so far. We address this issue through a novel visualization technique called trend mining that enables a decision maker to quickly comprehend the effect of variables on the structure of the objective space and easily discover interesting variable trends. The method uses moving averages with different windows to calculate an interestingness score for each variable along predefined reference directions. These scores are presented to the user in the form of an interactive heatmap. We demonstrate the working of the method and its usefulness through a benchmark and two engineering problems.

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  • 290.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Data mining methods for knowledge discovery in multi-objective optimization: Part A - Survey2017In: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 70, p. 139-159Article, review/survey (Refereed)
    Abstract [en]

    Real-world optimization problems typically involve multiple objectives to be optimized simultaneously under multiple constraints and with respect to several variables. While multi-objective optimization itself can be a challenging task, equally difficult is the ability to make sense of the obtained solutions. In this two-part paper, we deal with data mining methods that can be applied to extract knowledge about multi-objective optimization problems from the solutions generated during optimization. This knowledge is expected to provide deeper insights about the problem to the decision maker, in addition to assisting the optimization process in future design iterations through an expert system. The current paper surveys several existing data mining methods and classifies them by methodology and type of knowledge discovered. Most of these methods come from the domain of exploratory data analysis and can be applied to any multivariate data. We specifically look at methods that can generate explicit knowledge in a machine-usable form. A framework for knowledge-driven optimization is proposed, which involves both online and offline elements of knowledge discovery. One of the conclusions of this survey is that while there are a number of data mining methods that can deal with data involving continuous variables, only a few ad hoc methods exist that can provide explicit knowledge when the variables involved are of a discrete nature. Part B of this paper proposes new techniques that can be used with such datasets and applies them to discrete variable multi-objective problems related to production systems. 

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  • 291.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Ng, Amos H. C.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Deb, Kalyanmoy
    Department of Electrical and Computer Engineering, Michigan State University, USA.
    Data mining methods for knowledge discovery in multi-objective optimization: Part B - New developments and applications2017In: Expert systems with applications, ISSN 0957-4174, E-ISSN 1873-6793, Vol. 70, p. 119-138Article in journal (Refereed)
    Abstract [en]

    The first part of this paper served as a comprehensive survey of data mining methods that have been used to extract knowledge from solutions generated during multi-objective optimization. The current paper addresses three major shortcomings of existing methods, namely, lack of interactiveness in the objective space, inability to handle discrete variables and inability to generate explicit knowledge. Four data mining methods are developed that can discover knowledge in the decision space and visualize it in the objective space. These methods are (i) sequential pattern mining, (ii) clustering-based classification trees, (iii) hybrid learning, and (iv) flexible pattern mining. Each method uses a unique learning strategy to generate explicit knowledge in the form of patterns, decision rules and unsupervised rules. The methods are also capable of taking the decision maker's preferences into account to generate knowledge unique to preferred regions of the objective space. Three realistic production systems involving different types of discrete variables are chosen as application studies. A multi-objective optimization problem is formulated for each system and solved using NSGA-II to generate the optimization datasets. Next, all four methods are applied to each dataset. In each application, the methods discover similar knowledge for specified regions of the objective space. Overall, the unsupervised rules generated by flexible pattern mining are found to be the most consistent, whereas the supervised rules from classification trees are the most sensitive to user-preferences. 

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  • 292.
    Bandaru, Sunith
    et al.
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    Smedberg, Henrik
    University of Skövde, School of Engineering Science. University of Skövde, The Virtual Systems Research Centre.
    A parameterless performance metric for reference-point based multi-objective evolutionary algorithms2019In: GECCO '19: Proceedings of the Genetic and Evolutionary Computation Conference / [ed] Manuel López-Ibáñez, New York, NY, USA: ACM Digital Library, 2019, p. 499-506Conference paper (Refereed)
    Abstract [en]

    Most preference-based multi-objective evolutionary algorithms use reference points to articulate the decision maker's preferences. Since these algorithms typically converge to a sub-region of the Pareto-optimal front, the use of conventional performance measures (such as hypervolume and inverted generational distance) may lead to misleading results. Therefore, experimental studies in preference-based optimization often resort to using graphical methods to compare various algorithms. Though a few ad-hoc measures have been proposed in the literature, they either fail to generalize or involve parameters that are non-intuitive for a decision maker. In this paper, we propose a performance metric that is simple to implement, inexpensive to compute, and most importantly, does not involve any parameters. The so called expanding hypercube metric has been designed to extend the concepts of convergence and diversity to preference optimization. We demonstrate its effectiveness through constructed preference solution sets in two and three objectives. The proposed metric is then used to compare two popular reference-point based evolutionary algorithms on benchmark optimization problems up to 20 objectives.

    The full text will be freely available from 2020-08-01 00:00
  • 293.
    Banik, Kallol
    University of Skövde, School of Informatics.
    Investigation of Methods for Testing Aspect Oriented Software2014Independent thesis Advanced level (degree of Master (One Year)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Aspect-oriented programming is a comparatively new programming paradigm which intends to overcome some limitations that approaches such as procedural programming and object-oriented programming have. Traditional approaches are unable to properly capture some design decisions. Aspect-oriented programming introduces some new properties that we don’t find in the structural programming or object-oriented programming. New design patterns of aspect-oriented software introduce new fault types and new challenges for testing. Testing is an important part in the software development to produce quality software. Research on testing aspect-oriented software has been going on for several years but it still remains to invent testing approaches that cover all features of aspect-oriented software. This dissertation surveys test methods for aspect-oriented software and presents a comparison among the testing methods which reveals the strengths and weaknesses of current methods for testing of aspect-oriented software. This comparative overview of proposed test methods can be helpful for testers who intend to test aspect-oriented software. The conclusion presents the research contribution of this dissertation and proposes future work.

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  • 294.
    Banila, Beatrice
    University of Skövde, School of Humanities and Informatics.
    Attention-deficit hyperactivity disorder, medication and substance abuse2008Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Attention-Deficit Hyperactivity Disorder, (ADHD), is an established childhood psychiatric disorder, and it is the present diagnosis for children with major difficulties in the core symptoms; impulsiveness, attention and hyperactivity. The disorder is known to persist into adulthood and create major problems in coping with everyday life. With ADHD follows a vast variety of other conditions, which burdens the ADHD individuals even more. The major cause for the disorder is in heritage but also other possible explanations will be discussed. The main treatment for ADHD is psycho stimulants, such as methylphenidate and amphetamine. ADHD is associated with substance abuse and several articles in this essay will provide support for that. Is substance abuse in ADHD individuals a form of self-medication in order to ameliorate the symptoms or is the increased risk for substance abuse due to the stimulant medications? In this essay, I will describe what ADHD is, present what are its known causes, summarize the treatments available for ADHD, and discuss the relationships between ADHD and substance abuse.

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  • 295.
    Bankler, Jon Victor
    University of Skövde, School of Informatics.
    A chinese view on indie: How is ‘indie’ defined by professionals within the Chinese indie game industry?2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study aimed to explore which philosophies and opinions professionals within the Chinese indie game industry hold in relation to the indie concept. Indie is a short form of the word "independence”, and is used to describe certain products and creative practices within media such as video games. The term’s exact definition is however subject to discussion. This study aims to include Chinese game professionals in this discussion.

    The study was carried out in China through Game Hub Scandinavia (Game Hub Scandinavia, 2018) and in cooperation with Indienova. The participants that were interviewed in this study were all professionals within the Chinese game industry. The research tools developed for these interviews were two playable demos and a survey. The answers provided constituted as basis for the study’s concluding analysis.

    The data indicated that the Chinese indie developers define indie as a creative endeavour which products and underlying ambitions contrasts the commercially motivated game industry in China.

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    A Chinese view on indie
  • 296.
    Banks, H. T.
    et al.
    Center for Research in Scientific Computation North Carolina State University Raleigh, NC, USA.
    Banks, J. E.
    Undergraduate Research Opportunities Center (UROC) California State University, Monterey Bay Seaside, CA, USA.
    Bommarco, Riccardo
    Department of Ecology Swedish University of Agricultural Sciences Uppsala, Sweden.
    Curtsdotter, Alva
    Department of Ecology Swedish University of Agricultural Sciences Uppsala, Sweden.
    Jonsson, Tomas
    University of Skövde, School of Bioscience. University of Skövde, The Systems Biology Research Centre. Department of Ecology Swedish University of Agricultural Sciences Uppsala, Sweden.
    Laubmeier, A. N.
    Center for Research in Scientific Computation North Carolina State University Raleigh, NC, USA.
    Parameter estimation for an allometric food web model2017In: International journal of pure and applied mathematics, ISSN 1311-8080, E-ISSN 1314-3395, Vol. 114, no 1, p. 143-160Article in journal (Refereed)
    Abstract [en]

    The application of mechanistic models to natural systems is of interest to ecological researchers. We use the mechanistic Allometric Trophic Network (ATN) model, whichis well-studied for controlled and theoretical systems, to describe the dynamics of the aphidRhopalosiphum padi in an agricultural field. We diagnose problems that arise in a first attemptat a least squares parameter estimation on this system, including formulation of the modelfor the inverse problem and information content present in the data. We seek to establishwhether the field data, as it is currently collected, can support parameter estimation for theATN model.

  • 297.
    Bari, M. A.
    et al.
    University of Rajshahi.
    Islam, W.
    University of Rajshahi.
    Khan, A. R.
    University of Rajshahi.
    Mandal, Abul
    University of Skövde, The Systems Biology Research Centre. University of Skövde, School of Life Sciences.
    Antibacterial and Antifungal Activity of Solanum torvum (Solanaceae)2010In: International Journal of Agriculture & Biology, ISSN 1560-8530, Vol. 12, no 3, p. 386-390Article in journal (Refereed)
    Abstract [en]

    Leaves, stem, roots and inflorescence of Solanum torvum Sw. were extracted in two different organic solvents (chloroform & methanol). Antibacterial and antifungal effects of the extracts were tested on fifteen (six Gram positive & nine Gram negative) human  pathogenic  bacteria  and  on  eight  pathogenic  fungi.  Methanolic  extracts  of  roots  of  S.  torvum  exhibited  promising antibacterial  and  antifungal  effects  on  all  organisms  tested  in  comparison  with  that  observed  in  the  leaves,  stems  and inflorescence extracts. The toxicity of the extracts was in the following order; root>stem>inflorescence>leaf. The minimum inhibitory concentration (MIC) values of methanolic extract of roots of S. torvum were in the range between 64-128 µg mL -1 . Chloroform  extracts  of  roots  were  more  toxic  (LC 50  35.4629  ppm)  than  other  extracts  analyzed  in  Brine  shrimp  test.  In conclusion, S. torvum appears to be an attractive material for the development of antimicrobial drugs and environment friendly biopesticides.

  • 298.
    Barka, Ezedin
    et al.
    UAE University, United Arab Emirates.
    Mathew, Sujith
    UAE University, United Arab Emirates.
    Atif, Yacine
    UAE University, United Arab Emirates.
    Securing the Web of Things With Role-Based Access Control2015In: Codes, Cryptology, and Information Security: First International Conference, C2SI 2015, Rabat, Morocco, May 26-28, 2015, Proceedings - In Honor of Thierry Berger / [ed] Said El Hajji, Abderrahmane Nitaj, Claude Carlet, El Mamoun Souidi, Springer, 2015, p. 14-26Chapter in book (Refereed)
    Abstract [en]

    Real-world things are increasingly becoming fully qualified members of the Web. From, pacemakers and medical records to children’s toys and sneakers, things are connected over the Web and publish information that is available for the whole world to see. It is crucial that there is secure access to this Web of Things (WoT) and to the related information published by things on the Web. In this paper, we introduce an architecture that encompasses Web-enabled things in a secure and scalable manner. Our architecture utilizes the features of the well-known role-based access control (RBAC) to specify the access control policies to the WoT, and we use cryptographic keys to enforce such policies. This approach enables prescribers to WoT services to control who can access what things and how access can continue or should terminate, thereby enabling privacy and security of large amount of data that these things are poised to flood the future Web with.

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  • 299.
    Barkestedt, Filip
    University of Skövde, School of Informatics.
    Jämförelse av WebGL-teknologier vid rendering av heatmaps utifrån marin miljödata: Jämförelse mellan Three.js och X3DOM2018Independent thesis Basic level (degree of Bachelor), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    En stor kvantitet av miljödata samlas hela tiden in och för att dra nytta av all data behöver den förstås av de användarna som kan applicera kunskapen inom deras område. Visualiseringar tillåter användare att förstå datan och det är därför en viktig del av hur en användare kan ta del av den datan som samlas in. I detta arbete evalueras de WebGLbaserade teknologierna Three.js och X3DOM om vilken som är mest lämplig för att visualisera geospatial data på webben utifrån hur effektiva de är vid rendering av heatmaps. Två applikationer utvecklas, en baserat på Three.js och en på X3DOM. Mätningar utförs på varje applikation för att jämföra renderingstiden mellan teknologierna och en kvalitativ studie används för att evaluera deras användbarhet. Resultatet blev att Three.js är mer lämpligt för att visualisera geospatial data på webben.

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  • 300.
    Barrow, Devon K.
    et al.
    School of Strategy and Leadership, Faculty of Business and Law, Coventry University, Coventry, West Midlands, United Kingdom.
    Kourentzes, Nikolaos
    Lancaster University Management School, Department of Management Science, Lancaster, United Kingdom.
    Distributions of forecasting errors of forecast combinations: Implications for inventory management2016In: International Journal of Production Economics, ISSN 0925-5273, E-ISSN 1873-7579, Vol. 177, p. 24-33Article in journal (Refereed)
    Abstract [en]

    Inventory control systems rely on accurate and robust forecasts of future demand to support decisions such as setting of safety stocks. The combination of multiple forecasts is shown to be effective not only in reducing forecast errors, but also in being less sensitive to limitations of a single model. Research on forecast combination has primarily focused on improving accuracy, largely ignoring the overall shape and distribution of forecast errors. Nonetheless, these are essential for managing the level of aversion to risk and uncertainty for companies. This study examines the forecast error distributions of base and combination forecasts and their implications for inventory performance. It explores whether forecast combinations transform the forecast error distribution towards desired properties for safety stock calculations, typically based on the assumption of normally distributed errors and unbiased forecasts. In addition, it considers the similarity between in- and out-of-sample characteristics of such errors and the impact of different lead times. The effects of established combination methods are explored empirically using a representative set of forecasting methods and a dataset of 229 weekly demand series from a leading household and personal care UK manufacturer. Findings suggest that forecast combinations make the in- and out-of-sample behaviour more consistent, requiring less safety stock on average than base forecasts. Furthermore we find that using in-sample empirical error distributions of combined forecasts approximates well the out-of-sample ones, in contrast to base forecasts. 

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