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  • 201. Bulling, Andreas
    et al.
    Dachselt, Raimund
    Duchowski, Andrew T.
    Jacob, Robert J.
    Stellmach, Sophie
    Sundstedt, Veronica
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Gaze Interaction in the Post-WIMP World2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    With continuous progression away from desktop to post-WIMP applications, including multi-touch, gestural, or tangible interaction, there is high potential for eye gaze as a more natural human-computer interface in numerous contexts. Examples include attention-aware adaptations or the combination of gaze and hand gestures for interaction with distant displays. This SIG meeting provides a discussion venue for researchers and practitioners interested in gaze interaction in the post-WIMP era. We wish to draw attention to this emerging field and eventually formulate fundamental research questions. We will discuss the potential of gaze interaction for diverse application areas, interaction tasks, and multimodal user interface combinations. Our aims are to promote this research field, foster a larger research community, and establish the basis for a workshop at CHI 2013.

  • 202.
    Bulusu, Santosh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Sudia, Kalyan
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A Study on Cloud Computing Security Challenges2013Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Context: Scientific computing in the 21st century has evolved from fixed to distributed work environment. The current trend of Cloud Computing (CC) allows accessing business applications from anywhere just by connecting to the Internet. Evidence shows that, switching to CC organizations' annual expenditure and maintenance are being reduced to a greater extent. However, there are several challenges that come along with various benefits of CC. Among these include security aspects. Objectives: This thesis aims to identify security challenges for adapting cloud computing and their solutions from real world for the challenge that do not have any proper mitigation strategies identified through literature review. For this the objective is to identify existing cloud computing security challenges and their solutions. Identify the challenges that have no mitigation strategies and gather solutions/guidelines/practices from practitioners, for a challenge with more references but no mitigation strategies identified (in literature). Methods: This study presents a literature review and a snowball sampling to identify CC security challenges and their solutions/mitigation strategies. The literature review is based on search in electronic databases and snowball sample is based on the primary studies searched and selected from electronic databases. Using the challenges and their solutions identified form literature review, challenges with no mitigation strategies are identified. From these identified challenges with no mitigation strategies, a challenge with more references is identified. The surveys are employed in the later stages to identify the mitigation strategies for this challenge. Finally the results from the survey are discussed in a narrative fashion. Results: 43 challenges and 89 solutions are identified from literature review using snowball sampling. In addition to these mitigation strategies few guidelines are also identified. The challenge with more (i.e., more articles mentioning the challenge) and no mitigation identified is incompatibility. The responses identified for the three insecure areas of incompatibility (i.e., interoperability, migration and IDM integration with CC) in cloud computing security are mostly guidelines/practices opined by experienced practitioners. Conclusions: This study identifies cloud computing security challenges and their solutions. Where these (challenges and solutions) are common to cloud computing applications and cannot be generalized to either service or deployment models (viz. SaaS, PaaS, IaaS, etc.). The study also identifies that there are methods guidelines/practices identified from practitioners) to provide secure interoperability, migration and integration of on-premise authentication systems with cloud applications, but these methods are developed by individuals (practitioners/organization) specific to their context. The study also identifies the non-existence of global standards for any of these operations (providing interoperability/migration/IDM integration with cloud). This identified non-existence of global standards and guidelines could be help academics to know the state of practice and formulate better methods/standards to provide secure interoperability. The identified cloud computing security challenges (43) and solutions (89), can be referred by practitioners to understand which areas of security need to be concentrated while adapting/migrating to a cloud computing environment.

  • 203.
    Butt, Amar Majeed
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Sattar, Rana Asif
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    On Image Compression using Curve Fitting2010Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Context: Uncompressed Images contain redundancy of image data which can be reduced by image compression in order to store or transmit image data in an economic way. There are many techniques being used for this purpose but the rapid growth in digital media requires more research to make more efficient use of resources. Objectives: In this study we implement Polynomial curve fitting using 1st and 2nd curve orders with non-overlapping 4x4 and 8x8 block sizes. We investigate a selective quantization where each parameter is assigned a priority. The 1st parameter is assigned high priority compared to the other parameters. At the end Huffman coding is applied. Three standard grayscale images of LENA, PEPPER and BOAT are used in our experiment. Methods: We did a literature review, where we selected articles from known libraries i.e. IEEE, ACM Digital Library, ScienceDirect and SpringerLink etc. We have also performed two experiments, one experiment with 1st curve order using 4x4 and 8x8 block sizes and second experiment with 2nd curve order using same block sizes. Results: A comparison using 4x4 and 8x8 block sizes at 1st and 2nd curve orders shows that there is a large difference in compression ratio for the same value of Mean Square Error. Using 4x4 block size gives better quality of an image as compare to 8x8 block size at same curve order but less compression. JPEG gives higher value of PSNR at low and high compression. Conclusions: A selective quantization is good idea to use to get better subjective quality of an image. A comparison shows that to get good compression ratio, 8x8 block size at 1st curve order should be used but for good objective and subjective quality of an image 4x4 block size at 2nd order should be used. JPEG involves a lot of research and it outperforms in PSNR and CR as compare to our proposed scheme at low and high compression ratio. Our proposed scheme gives comparable objective quality (PSNR) of an image at high compression ratio as compare to the previous curve fitting techniques implemented by Salah and Ameer but we are unable to achieve subjective quality of an image.

  • 204. Butt, Rehman
    et al.
    Johansson, Stefan J.
    Where do we go now? Anytime algorithms for path planning2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    Commercial computer games has become one of the largest industries in the area of entertainment. Real Time Strategy (Rts) based games is one of the most important among different types of computer games and is also considered to be a good research platform within Artificial Intelligence (Ai). There exists a number of algorithms that can deal with the Ai related problems of this domain, e.g. the ones of getting as cheap or fast as possible from one point to another (i.e. path planning). However most of the algorithms used in academia are better suited for problems that do not need to be solved within tight time frames. Anytime algorithms (Aa) are algorithms that can be stopped at any point in time and yet come up with a preliminary solution. We believe that by making algorithms anytime, we can optimize their behaviors to better suit the Rts domain. This study will introduce a tool for evaluating path planning algorithms and compare the performances of A*, Recursive Best First Search (Rbfs), Potential Fields (Pf) and their anytime versions for the path planning problem.

  • 205.
    Börstler, Jürgen
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Kuzniarz, Ludwik
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Alphonse, Carl
    Sanders, Bill
    Smialek, Michal
    Teaching Software Modeling in Computing Curricula2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    Modeling is a key skill in software development. The ability to develop, manipulate and understand models for software is therefore an important learning objective in many CS/SE courses. In this working group, we investigated how and when (software) modeling is taught to help us better understand the key issues in teaching (software) modeling. Several shortcomings were found in common curricula, both in their understanding of the term "modeling" and in how they address its teaching. This WG report summarizes the fi ndings and formulates recommendations on the inclusion of software modeling courses in future CS/SE curricula.

  • 206. Bǎdoi, Cornelia Ionela
    et al.
    Croitoru, Victor
    Popescu, Adrian
    Comparative performance evaluation of IPSAG and HC-IPSAG Cognitive Radio routing protocols2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The paper presents the characteristics of two recently suggested Cognitive Radio (CR) routing protocols, IP Spectrum Aware Geographic (IPSAG) and Head-Cluster IPSAG (HCIPSAG) protocols, relative to other multi-hop routing protocols. The comparison is guided by specific CR performance criteria, as mobility and spectrum availability awareness. The protocols are representative for different multi-hop routing protocol types. The analysis shows that our protocols respond well to CR demands, especially at high mobility. The results are sustained by statistical results obtained through simulations. However, the price is an increased overhead regarding the control information needed to perform routing.

  • 207. Bǎdoi, Cornelia Ionela
    et al.
    Croitoru, Victor
    Popescu, Adrian
    HC-IPSAG Cognitive Radio routing protocol: Models and performance2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The paper is about a new routing protocol suggested for Cognitive Radio Networks (CRN) called Head Cluster IP Spectrum Aware Geographic (HC-IPSAG) and the associated performance. The protocol is an extension of the formerly advanced IPSAG routing protocol, for the case of larger CRNs. Splitting of the CRN domain into clusters is considered here. Each cluster is represented by a head node and the inter-cluster routing is done by using the IPSAG routing concepts within the virtual network created by the cluster head nodes. A CRN simulation model has been developed to study the performance of HC-IPSAG. Our results show that the protocol is performing well in the case of high mobility as well as the performance decreases with the growth of the cluster number.

  • 208. Bǎdoi, Cornelia Ionela
    et al.
    Croitoru, Victor
    Popescu, Adrian
    Simulation of the ipsag cognitive radio routing protocol-Stationary case2011Ingår i: UPB Scientific Bulletin, Series C: Electrical Engineering, ISSN 1454-234X, Vol. 73, nr 2, s. 193-204Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Cognitive Radio Networks (CRNs) have now become very popular due to their innovative idea of increasing the spectrum efficiency by smart secondary users, which are using the unused licensed channels. In the CRN context we have suggested a new routing algorithm called IP Spectrum Aware Geographic algorithm (IPSAG) [1]. The paper presents the validation of the IPSAG correctness in the case of stationary CR nodes. A CRN model is created by overloading a channel map with a node map, and then, inside the CRN, it is proved that the source-destination path is successfully found in the majority of the cases.

  • 209.
    Cai, Xiao
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Duan, Tie
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A Reliable Study of Software Reputation Based on User Experience2009Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Many users have such experience that after downloading or buying a software product, it does not work well as you anticipated. However, it is lucky to some extent because many other users download malicious software applications from Internet directly. Those problems cause people to think carefully and seriously about reputation of software. As it is said, the software reputation is very important for users to buy or use software applications, especially for those people who have very few knowledge of computer technologies. Many researches provided various kinds of technical methods to verify whether a software product has good reputation or not. This paper mainly focuses on software reputation research based on user experience. Nowadays, one effective way to evaluate experience of users is Web Survey, which has increased in popularity because of its convenience, ease of use, low cost, and quickness in knowing the result of a survey. Web survey is widely used to gather user opinions on various purposes. However, most such systems are too weak to keep reliability, and sometimes with a complete fallacious result. After introducing a number of methodologies, we present a concept design of more reliable web survey system based on user experience of software products that are under estimation. Development tools and some web technologies are discussed, such as PHP and JavaScript that will be used in implementing the web survey system based on concept design of this paper in the future. PHP (Hypertext Preprocessor) is a simple and practical dynamic web page development language, and it is widely used as a multipurpose scripting language embedded in HTML (Hypertext Marked Language). JavaScript is a scripting language and is primarily used in the client-side for development of dynamic websites. Therefore, these two technologies are proper to be applied. In order to solve the defined research problems, only proposing a method of web survey is not sufficient. The more significant point is reliability of that designed system. Therefore, Digital Signature technology is introduced and described, which will be used for user verification in the system for strengthening reliability of the web survey. The digital signature is widely used in electronic commerce, and it can authenticate one user’s identity effectively. Another important technology that can increase the reliability of comments from users is Reading Registry. As the “Windows” system is the most popular operation system on personal computers today, we choose to study it in this paper. The registry is a basic database of windows system that records every software applications’ information there. So by reading the information in registry, it is easily known whether a user’s comment is valid or not. If the registry records the under estimation software, it means that user indeed used the software and his/her comments are worth consideration, otherwise the comments are too untruthful to be accepted. Although the web survey system is presented and illustrated by using concept design of this paper, a series of scenarios have been designed to test the real processes of the system. Three main series of scenarios were designed corresponding to digital signature method, registry check method and reputation calculation process respectively. After analyzing the process, those applied methods do strengthen the reliability of the web survey system. Admittedly, there are problems that are not under the control of the system. In the future work, we will carry on studies on them.

  • 210.
    Carlsson, Bengt
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Ayalew, Tigist
    Kidane, Tigist
    Identification and evaluation of security activities in agile projects2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    We compare four high-profile waterfall security-engineering processes (CLASP, Microsoft SDL, Cigital Touchpoints and Common Criteria) with the available preconditions within agile processes. Then, using a survey study, agile security activities are identified and evaluated by practitioners from large companies, e.g. software and telecommunication companies. Those activities are compared and a specific security engineering process is suggested for an agile process setting that can provide high benefit with low integration cost.

  • 211. Carlsson, Bengt
    et al.
    Davidsson, Paul
    Jacobsson, Andreas
    Johansson, Stefan J.
    Persson, Jan A.
    Security aspects on inter-organizational cooperation using wrapper agents2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    The significance of electronic information exchange in inter-organizational cooperation is well-known. We will here focus on the particular requirements of SMEs. We describe a general wrapper agent solution based on open source freeware that makes it possible (in principle) for any business system to exchange information with any other business system. It has been successfully applied in a pilot study involving two companies in a transport chain using different business systems. We also suggest further improvements by addressing security issues as well as an extended, possibly dynamic, set of involved companies and higher levels of cooperation.

  • 212.
    Carlsson, Bengt
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Jacobsson, Andreas
    An evolutionary view of collective intelligence2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    Based on the question "How can people and computers be connected so that - collectively - they act more intelligently than any individuals, groups, or computers have ever done before?" we propose an evolutionary approach. From this point of view, there are of course fundamental differences between man and machine. Where one is artificial, the other is natural, and where the computer needs to process, the brain must adapt. We propose the use of culturally inherited units, i.e., memes, for describing collective knowledge storage. Like the genes, memes have the ability to be inherited to the next generation. Genes appear independently of our society while memes are a result of our cultural development. The concept of collective intelligence may involve a new kind of meme, entirely emerging within the intersection between man and machine, i.e., outside the scope of human control. The challenge is to model this behavior without overriding constraints within basic evolutionary vs. machine settings.

  • 213.
    Carlsson, Bengt
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Jacobsson, Andreas
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Om säkerhet i digitala ekosystem2012Bok (Övrigt vetenskapligt)
    Abstract [en]

    Vi är på väg mot ett samhälle som styrs av programvarukod och där digitala marknadskrafter tar över allt större delar av våra traditionella verksamhetsområden. Om säkerhet i digitala ekosystem handlar om människorna, tekniken och ekonomin som formar det dynamiska och komplexa, men även stundtals fientliga ekosystem som dagens Internet utgör. Globala trender som webb 2.0, sociala nätverk och datamoln i kombination med dominerande företag som Facebook, Amazon och Google har på kort tid förändrat förutsättningarna för nätets digitala invånare.Samtidigt har det skett en ökning av illvilliga aktiviteter i form av virus och spionprogram, men också genom diverse sociala tekniker. Som en konsekvens har vi ett digitalt ekosystem där såväl goda som mindre goda beteenden skapar dynamik och spänningar, och där mötet mellan artificiella instanser av både människor och företag väcker spännande frågor. Särskilt viktiga spörsmål har med människans behov av säkerhet,privatliv, tillit och trygghet att göra, men också om våra biologiska beteendemönster, kognitiva förutsättningar, ekonomiska affärsmodeller och tekniska upptäckariver. I denna myriad av perspektiv, områden och företeelser tar boken sin utgångspunkt.

  • 214.
    Castaño, Víctor
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A Framework for an Intelligent and Adaptive Planning of Rehabilitation Therapies2011Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Context. In the forthcoming years Healthcare Systems will become better informed, more efficient and particularly focused on the patient through the integration of Information and Communication Technologies. Medical Rehabilitation is an example of a field prone for this evolution. Here, disciplines such as Software Engineering will play a key role during the transformation. Objectives. This study pursues to understand todays rehabilitation therapies and procedures, to conceive how future computer-aided rehabilitation systems should be constructed and to provide a coherent framework that conceptualizes the relationship of their main components and interactions. Methods. The overall thesis work involves a combination of different research methodologies, which vary from literature reviews, empirical observations and semi-structured ethnographic interviews, to constructive research, through software architectural designs. Results. FIAP-RT is a framework created to support the new paradigm on how future software tools oriented to Medical Rehabilitation should be constructed with views to achieve quality attributes such as interoperability, availability, security, accessibility, usability or reliability. Conclusions. This study reveals that it is generally hard to find a real socialization and dissemination of the know-how that is being constantly produced within rehabilitation centers. In addition, it is has been shown how applied Software Engineering can help to integrate advanced solutions even though further evaluation would be needed to validate the proposed framework.

  • 215.
    Cederström, Andreas
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    On using Desktop Grid Computing in software industry2010Självständigt arbete på avancerad nivå (magisterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Context. When dealing with large data sets and heavy calculations the common solution is clusters, supercomputers or Grids of these two. However, there are ways of gaining large computational power by utilizing the unused cycles of regular home or office computers, this are referred to as Desktop Grids. Objectives. In this study we review the current field of solutions for open source Desktop Grid computing capable of dealing with a heterogeneous set of clients and dynamic size of the Desktop Grid. We investigate current use, interest of use and priority of key attributes of Desktop Grids. Finally we want to show how time effective Desktop Grids are compared to execution on a single machine and in the process show effort needed to setup a Desktop Grid and start computing. The overall purpose of this study is to provide a path for industry organizations to take when taking the first step into Desktop Grid computing. Methods. We use a systematic review to collect information of existing open source Desktop Grid solutions. Studies are selected based on inclusion criterions and a quality assessment. A survey questioner is used to assess industry usage, interest and prioritization of attributes of Desktop Grids. We will conduct an experiment to show execution speedup as well as setup effort. Results. We found ten open source Desktop Grids fulfilling our requirements. The survey shows that Desktop Grids is used to a very little extent within industry while a majority of the participants state that there is an interest for Desktop Grids. As result of the experiment, we can say that we achieved very high speedup and that effort needed to setup a Desktop Grid is about 40 hours for one person with no prior experience to the selected Desktop Grid system. Conclusions. We conclude that industry organizations have a possible need for Desktop Grids but in order to be more successful, Desktop Grid developers must put more effort into areas as automated testing and code compilation.

  • 216.
    Chalamalasetty, Kalyani
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Architecture for IMS Security to Mobile:Focusing on Artificial Immune System and Mobile Agents Integration2009Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    The IP Multimedia Subsystem (IMS) is an open IP based service infrastructure that enables an easy deployment of new rich multimedia services mixing voice and data. The IMS is an overlay network on top of IP that uses SIP as the primary signaling mechanism. As an emerging technology, the SIP standard will certainly be the target of Denial of Service (DoS) attacks and consequently IMS will also inherit this problem. The objective of proposed architecture for IMS is to cram the potential attacks and security threats to IP Multimedia Subsystem (IMS) and explore the security solutions developed by 3GPP. This research work incorporates the ideas of immune system and multiagent architecture that is capable of detecting, identifying and recovering from an attack. The proposed architecture protects IMS core components i.e. P-CSCF (Proxy- Call Session Control Function), I-CSCF (Interrogating-Call Session Control Function), S-CSCF (Serving Call Session Control Function) and HSS (Home Subscriber Server) from external and internal threats like eavesdropping, SQL injection and denial-ofservice (DoS) attacks. In the first level i.e. CPU under normal load all incoming and out going messages were investigated to detect and prevent SQL injection. Second level considers Denial of Service (DOS) attacks when CPU load exceeds threshold limit. Proposed architecture is designed and evaluated by using an approach called Architecture Tradeoff Analysis Method (ATAM). The results obtained confirm consistency of the architecture.

  • 217. Chatzipetrou, Panagiota
    et al.
    Angelis, Lefteris
    Barney, Sebastian
    Wohlin, Claes
    Software product quality in global software development: Finding groups with aligned goals2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    The development of a software product in an organization involves various groups of stakeholders who may prioritize the qualities of the product differently. This paper presents an empirical study of 65 individuals in different roles and in different locations, including on shoring, outsourcing and off shoring, prioritizing 24 software quality aspects. Hierarchical cluster analysis is applied to the prioritization data, separately for the situation today and the ideal situation, and the composition of the clusters, regarding the distribution of the inherent groupings within each of them, is analyzed. The analysis results in observing that the roles are not that important in the clustering. However, compositions of clusters regarding the onshore-offshore relationships are significantly different, showing that the offshore participants have stronger tendency to cluster together. In conclusion, stakeholders seem to form clusters of aligned understanding of priorities according to personal and cultural views rather than their roles in software development.

  • 218. Chatzipetrou, Panagiota
    et al.
    Angelis, Lefteris
    Rovegård, Per
    Wohlin, Claes
    Prioritization of issues and requirements by cumulative voting: A compositional data analysis framework2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    Cumulative Voting (CV), also known as Hundred-Point Method, is a simple and straightforward technique, used in various prioritization studies in software engineering. Multiple stakeholders (users, developers, consultants, marketing representatives or customers) are asked to prioritize issues concerning requirements, process improvements or change management in a ratio scale. The data obtained from such studies contain useful information regarding correlations of issues and trends of the respondents towards them. However, the multivariate and constrained nature of data requires particular statistical analysis. In this paper we propose a statistical framework; the multivariate Compositional Data Analysis (CoDA) for analyzing data obtained from CV prioritization studies. Certain methodologies for studying the correlation structure of variables are applied to a dataset concerning impact analysis issues prioritized by software professionals under different perspectives. These involve filling of zeros, transformation using the geometric mean, principle component analysis on the transformed variables and graphical representation by biplots and ternary plots.

  • 219. Chen, Yuanfang
    et al.
    Li, Mingchu
    Shu, Lei
    Wang, L.
    Duong, Quang Trung
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    The scheme of mitigating the asymmetric links problem in wireless sensor networks2010Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper investigates the radio irregularity (RI) phenomenon and its impact on communication performance in wireless sensor networks (WSNs). Based on the theoretical analysis, we find that the RI phenomenon induces the asymmetric links problem. According to this discovery, we propose a novel HCT (Hop-count Correction Tree) scheme to handle this problem. HCT utilizes graph theoretical method to get a search tree and correct the hop count error that appears in the adjacent nodes. Practical results obtained from testbed experiments demonstrate that this solution can greatly improve localization accuracy in the presence of RI

  • 220.
    Cheng, Chow Kian
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Permadi, Rahadian Bayu
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Towards an Evaluation Framework for Software Process Improvement2009Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Software has gained an essential role in our daily life in the last decades. This condition demands high quality software. To produce high quality software many practitioners and researchers put more attention on the software development process. Large investments are poured to improve the software development process. Software Process Improvement (SPI) is a research area which is aimed to address the assessment and improvement issues in the software development process. One of the most important aspects in software process improvement is to measure the results gained from the embarked process change. Without measuring the results, it is hard to tell whether the goals have been achieved or not. However, measurement for software process improvement is not a trivial task. Furthermore, there is no common systematic methodology that can be used to help measuring the performance of software process improvement initiatives. This thesis is intended to provide basic key concepts for the effective measurement and evaluation of the outcome of software process improvement. A major part of this thesis presents the systematic review in evaluating the outcome of software process improvement. The systematic review is aimed at the identification of the major issues in software process improvement evaluation and to gather the requirements for a software process improvement measurement and evaluation framework. Based on the results of the systematic review, a measurement and evaluation model is formulated. The objective of the model is to provide the groundwork for a software process improvement measurement and evaluation framework. The model is deemed to be applicable in a broad spectrum of scenarios by providing concepts that are independent from specific SPI initiatives.

  • 221. Cherif, Redha
    et al.
    Davidsson, Paul
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Software Development Process Simulation: Multi Agent-Based Simulation versus System Dynamics2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    We present one of the first actual applications of Multi Agent-Based Simulation (MABS) to the field of software process simulation modelling (SPSM). Although there are some recent attempts to do this, we argue that these fail to take full advantage of the agency paradigm. Our model of the software development process integrates individual-level performance, cognition and artefact quality models in a common simulation framework. In addition, this framework allows the implementation of both MABS and System Dynamics (SD) simulators using the same basic models. As SD is the dominating approach within SPSM, we are able to make relevant and unique comparisons between it and MABS. This enabled us to uncover quite interesting properties of these approaches, e.g., that MABS re-flects the problem domain more realistically than SD.

  • 222. Cherif, Redha
    et al.
    Davidsson, Paul
    Software Development Process Simulation: Multi Agent-Based Simulation versus System Dynamics2010Ingår i: Multi Agent Based Simulation X, Lecture Notes in Computer Science, Springer , 2010Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    We present one of the first actual applications of Multi Agent-Based Simulation (MABS) to the field of software process simulation modelling (SPSM). Although there are some recent attempts to do this, we argue that these fail to take full advantage of the agency paradigm. Our model of the software development process integrates individual-level performance, cognition and ar- tefact quality models in a common simulation framework. In addition, this framework allows the implementation of both MABS and System Dynamics (SD) simulators using the same basic models. As SD is the dominating ap- proach within SPSM, we are able to make relevant and unique comparisons be- tween it and MABS. This enabled us to uncover quite interesting properties of these approaches, e.g., that MABS reflects the problem domain more realisti- cally than SD.

  • 223.
    Chowdhury, Mohammad
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Iqbal, Mohammad
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    A new solution approach for simultaneous mobility issues in seamless handover2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper proposes a new solution approach for the simultaneous mobility issues in seamless handover. An alternative scheme is designed to minimize handover latency between two different networks with location management support while simultaneous handover occurs. One of the most emerging techniques in recent research projects for mobility management is mobile Stream Transmission Control Protocol (mSCTP). The multi-homing feature of Stream Control Transmission Protocol (SCTP) and dynamic address reconfiguration (DAR) extension of SCTP are applied in the proposed solution to achieve improved seamless performance. We used an additional Location Server (LS) to ensure location management between simultaneously moving mobile nodes (MNs) while simultaneous handover occurs. This research is dedicated to design a new model of simultaneous mobility based on 'Step-length' and the implementation of the model i.e., mSCTP with LS to solve the simultaneous mobility issues. 'Step-length' is defined as the random distance travelled by the simultaneously moving MNs in each step when location changes. The proposed scheme implemented on NS2 and performance evaluations are scrutinized to demonstrate the comparison of proposed simultaneous handover latency with LS and in absence of LS. The results show that our proposed approach has improved performance in reducing handover delay as well as handling simultaneous mobility issues in seamless handover.

  • 224.
    Chtivelband, Igor
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    HistoryLane: Web Browser History Visualization Method2012Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    With the evolution of Internet, users exploit it increasingly intensively for achieving their goals: sending emails, playing games, watching videos, reading news. They do it through Web browsers, that may vary in exact implementation, but have similar core functionalities . One of these core functionalities is the access to a browsing history. However, as browsing patterns are getting more complex, the traditional history tools become insufficient. Visualization of browsing history might be helpful in that case. In this study we propose a novel approach for browsing history visualization, named HistoryLane, which ts the parallel browsing paradigm, common for modern browsers. The main goal of HistoryLane is enabling the user to gain insight into his own or into other users' parallel browsing patterns over time. Principles of HistoryLane visualization approach are formulated based on recommendations, found during structured literature review. These principles constitute the base for a prototype, which was implemented as a Fire- fox extension. To evaluate the e ffectiveness of HistoryLane we conducted a survey and a quantitative experiment. The results of the evaluation show that HistoryLane is perceived by users as effective and intuitive method for browsing history visualization.

  • 225.
    Chu, Thi My Chin
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    MIMO Incremental AF Relay Networks with TAS/MRC and Adaptive Modulation2013Konferensbidrag (Övrigt vetenskapligt)
    Abstract [en]

    In this paper, we study the use of adaptive modulation (AM) for a dual-hop multiple-input multiple-output (MIMO) network with transmit antenna selection (TAS) at the transmitter and maximal ratio combining (MRC) at the receiver. Our system deploys incremental amplify-and-forward (AF) relaying with AM to forward the source signal. A switching policy for selecting between the relaying and the direct communication is utilized to maximize spectrum efficiency. In particular, we derive closed-form expressions for the outage probability, spectrum efficiency, and bit error rate (BER) for the considered system over Nakagami-m fading. The considered network not only takes advantage of TAS transmission such as achieving full diversity order with low transmit complexity but also inherits the beneficial feature of AM such as spectrum efficiency improvement. Reference

  • 226. Chu, Thi My Chinh
    et al.
    Duong, Quang Trung
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    MRT/MRC for Cognitive AF Relay Networks under Feedback Delay and Channel Estimation Error2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we examine the performance of multiple-input multiple-output cognitive amplify-and-forward (AF) relay systems with maximum ratio transmission (MRT). In particular, closed-form expressions in terms of a tight upper bound for outage probability (OP) and symbol error rate (SER) of the system are derived when considering channel estimation error (CEE) and feedback delay (FD) in our analysis. Through our works, one can see the impact of FD and CEE on the system as well as the benefits of deploying multiple antennas at the transceivers utilizing the spatial diversity of an MRT system.

  • 227. Chu, Thi My Chinh
    et al.
    Duong, Quang Trung
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Outage Probability and Ergodic Capacity for MIMO-MRT Systems under Co-Channel Interference and Imperfect CSI2011Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we investigate the performance of multiple-input multiple-output (MIMO) systems deploying maximum ratio transmission (MRT). Our analysis takes into account not only imperfect channel estimation at the receiver and feedback delay at the transmitter, but also includes co-channel interference (CCI). In particular, we first derive the statistical properties of the signal-to-interference-plus-noise ratio (SINR). Next, we obtain a closed-form expression for outage probability and an approximation for capacity. Finally, we show the consistency between analytical results and Monte-Carlo simulations. Our results indicate that the system performance is improved considerably in proportion to the number of transceiver antennas. Conversely, the outage probability increases, and the capacity decreases significantly with the severity of channel estimation error, feedback delay, and CCIs.

  • 228.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Duong, Quang Trung
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Performance analysis for multiple-input multiple output- maximum ratio transmission systems with channel estimation error, feedback delay and co-channel interference2013Ingår i: IET Communications, ISSN 1751-8628, Vol. 7, nr 4, s. 279-285Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In this study, the authors analyse the impact of channel estimation error (CEE), feedback delay (FD), and co-channel interference (CCI) on the performance of multiple-input multiple-output (MIMO) systems deploying maximum ratio transmission (MRT). In particular, the authors derive closed-form expressions for the ergodic capacity and the symbol error rate (SER) as well as the outage probability (OP). In addition, to reveal the effect of CEE, FD and CCI on the MIMO-MRT system, the authors adopt more simplified and tractable formulas in terms of asymptotic expressions for the ergodic capacity, SER and OP. The analysis shows that the system performance is degraded considerably under imperfect transmission conditions such as CEE, FD and CCI. However, the authors can compensate part of this degradation by deploying MRT transmission with a large number of antennas at the transmitter and receiver. Finally, the selected examples exhibit consistency between analytical results and Monte Carlo simulations.

  • 229.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Duong, Quang Trung
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Elkashlan, Maged
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Beamforming Transmission in Cognitive AF Relay Networks with Feedback Delay2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we investigate the effect of feedback delay on outage probability (OP) and symbol error rate (SER) of cognitive amplify-and-forward (AF) relay networks with beamforming transmission in Rayleigh fading environment. It is assumed that the secondary transmitter and the secondary receiver are equipped with multiple antennas, whereas the relay and the primary user comprise of a single antenna. Furthermore, in this system, the secondary users use the underlay scheme in which the secondary transmitter and the relay can coexist with the primary user as long as their interference caused to the primary receiver is below a predefined threshold. Through our analysis, numerical results are provided to show the level of degradation of cognitive AF relay systems in proportion to the degree of feedback delay. In addition, we also present the effect of the number of antennas at the secondary transceiver on the performance of the considered system.

  • 230.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Amplify-and-Forward Relay Assisting both Primary and Secondary Transmissions in Cognitive Radio Networks over Nakagami-m Fading2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we study the performance for the primary and secondary transmissions in cognitive radio networks where the amplify-and-forward (AF) secondary relay helps to transmit the signals for both the primary and secondary transmitters over independent Nakagami-m fading. First, we derive exact closed-form expressions for outage probability and symbol error rate (SER) of the primary network. Then, we derive an exact closed-form expression for outage probability and a closed-form expression of a tight upper bound for SER of the secondary network. Furthermore, we also make a comparison for the performance of the primary system with and without the help of the secondary relay.

  • 231.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Cognitive MIMO AF Relay Network with TAS/MRC Under Peak Interference Power Constraint2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we study the use of transmit antenna selection (TAS) and maximal ratio combining (MRC) for a cognitive multiple-input multiple-output (MIMO) amplify-andforward (AF) relay network. We focus on the scenario that each of the source and relay selects only a single antenna which maximizes the instantaneous signal-to-noise ratio (SNR) to transmit and forward the signal while the receiver combines the signals from all receive antennas. Utilizing TAS, the considered cognitive network not only offers advantages such as achieving full diversity order with low transmit complexity but also reduces the interference induced to the primary transmission as compared to maximum ratio transmission (MRT). This in turn becomes beneficial for the secondary network when this network operates under the interference power constraint of the primary receiver. In particular, we derive expressions for the outage probability and symbol error rate (SER) of the network to evaluate the system performance. We also develop an asymptotic analysis for the outage probability and the SER to obtain diversity and coding gain. With the tractable asymptotic expressions, the effect of network parameters such as the number of antennas, the transmission distances, and the interference power constraint of the primary receiver on the system performance are readily revealed.

  • 232.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    MIMO Incremental AF Relay Networks with TAS/MRC and Adaptive Modulation2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we study the use of adaptive modulation (AM) for a dual-hop multiple-input multiple-output (MIMO) network with transmit antenna selection (TAS) at the transmitter and maximal ratio combining (MRC) at the receiver. Our system deploys incremental amplify-and-forward (AF) relaying with AM to forward the source signal. A switching policy for selecting between the relaying and the direct communications is utilized to maximize spectrum efficiency. In particular, we derive expressions for the outage probability, spectrum efficiency, and bit error rate (BER) for the considered system over Nakagamim fading. The considered network not only takes advantage of TAS transmission such as achieving full diversity order with low transmit complexity but also inherits the beneficial feature of AM such as spectrum efficiency improvement.

  • 233.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    On the Performance of Underlay Cognitive Radio Networks Using M/G/1/K Queuing Model2013Ingår i: IEEE Communications Letters, ISSN 1089-7798, E-ISSN 1558-2558, Vol. 17, nr 5, s. 876-879Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Motivated by a realistic scenario for cognitive radio systems, we model the underlay cognitive radio network (CRN) under interference power constraint imposed by the primary network as an M/G/1/K queueing system. The respective embedded Markov chain is provided to analyze several key queueing performance measures. In particular, the equilibrium probabilities of all states are derived and utilized to evaluate throughput, blocking probability, mean packet transmission time, mean number of packets in the system, and mean waiting time of an underlay CRN with Nakagami-m fading channels.

  • 234.
    Chu, Thi My Chinh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Phan, Hoc
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Zepernick, Hans-Jürgen
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Opportunistic Spectrum Access for Cognitive Amplify-and-Forward Relay Networks2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we study the performance of cognitive amplify-and-forward (AF) relay networks where the secondary users opportunistically access M licensed bands of the primary users over Nakagami-m fading channels. In order to enhance the accuracy of spectrum sensing and strongly protect the primary users from being interfered by the secondary transmission, collaborative spectrum sensing is deployed among the secondary transmitter, secondary relay, and secondary receiver. In particular, an analytical expression for the capacity of the considered network is derived. Numerical results are provided to show the influence of the arrival rate of the primary users on the channel utilization of licensed bands. Finally, the impact of the number of the licensed bands, channel utilization of the primary users, false alarm probability, and transmission distances on the capacity of the considered system are investigated.

  • 235. Ciszkowski, Tomasz
    et al.
    Eliasson, Charlott
    Fiedler, Markus
    Kotulski, Zbigniew
    Lupu, Radu
    Mazurczyk, Wojciech
    SecMon: end-to-end quality and security monitoring system2008Ingår i: Annales UMCS Informatica, ISSN 1732-1360, Vol. AI 8, nr 1, s. 185-201Artikel i tidskrift (Refereegranskat)
    Abstract [sv]

    Ett system som hjälper att förbättra kvaliten och säkerheten i röstkommunikation via Internet presenteras. Mekanismen bygger på P2P teknik och behöver förhållandevis små resurser. Informationsutbyte sker med hjälp av gömda kanaler. Mer detaljer finns i den engelska versionen.

  • 236. Ciszkowski, Tomasz
    et al.
    Mazurczyk, Wojciech
    Kotulski, Zbigniew
    Hossfeld, Tobias
    Fiedler, Markus
    Collange, Denis
    Towards Quality of Experience-based Reputation Models for Future Web Service Provisioning2009Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield general scoring of a particular behavior. Thus, they are likely to become an important ingredient of Future Internet. Parameters being under evaluation by reputation system may vary greatly and, particularly, may be chosen to assess the users’ satisfaction with (composite) web services. Currently, this satisfaction is usually expressed with QoE, which represents subjective users’ opinions. The goal is to predict users’ satisfaction based on reputation values. This may be beneficial for service providers in terms of checking the fulfillment of SLAs, for retaining QoE on the satisfaction level for other users sharing the same network or service resources, and for providing the users with indications which resource to choose in order to maximize its experience.

  • 237. Ciszkowski, Tomasz
    et al.
    Mazurczyk, Wojciech
    Kotulski, Zbigniew
    Hossfeld, Tobias
    Fiedler, Markus
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Collange, Denis
    Towards Quality of Experience-based reputation models for future web service provisioning2012Ingår i: Telecommunications Systems, ISSN 1018-4864, E-ISSN 1572-9451, Vol. 51, nr 4, s. 283-295Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper concerns the applicability of reputations systems for assessing Quality of Experience (QoE) for web services in Future Internet. Reputation systems provide mechanisms to manage subjective opinions in societies and yield a general scoring of a particular behavior. Thus, they are likely to become an important ingredient of Future Internet. Parameters being under evaluation by a reputation system may vary greatly and, particularly, may be chosen to assess the users’ satisfaction with (composite) web services. Currently, this satisfaction is usually expressed by QoE, which represents subjective users’ opinions. The goal of this paper it to present a novel framework of web services where a reputation system is incorporated for users satisfaction tracking and prediction. This approach is a beneficial tool, which enables providers to facilitate service adaptation according to users’ expectations and maintain QoE on a satisfying level. Presented reputation system operates in an environment of composite services running on a client and server side. It makes this approach highly suitable for effective QoE differentiating and maximizing user experience for specific customer profiles even the service and network resources are shared.

  • 238.
    Civelek, Ülkan Fuat
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    An Agent-Based Approach for Automating the Process of Charging Plug-in Electric Vehicles2010Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    The study of Power TAC is a Multi-Agent competitive simulation test-bed, providing opportunity to simulate research and developments of electronic agents which can manage the tasks of the consumers and energy resources in a virtual energy infrastructure. According to the Power TAC scenario, Plug-in Electrical Vehicles are a special type of consumers that interact with this infrastructure and sometimes with the producers through aggregators. The aim of this study is modeling an intelligent Plug-in Electric vehicle agent for Power TAC that acts as an intermediary between Power TAC grid and vehicle owners. The proposed agent acts autonomously and is capable of making decisions about its energy needs by learning the driving behaviors and other preferences of these vehicle owners in a specified time interval. These agents will be able to make decisions about buying energy from the grid when the charging process is necessary or sell their energy back to the grid when the conditions of the electricity market are sufficiently attractive. The objective of this study is to model a Multi-Agent system for automating the process of charging the plug-in Vehicle Agents in Power TAC scenario by determining the necessary agents and the simulation environment where the agents constructed and simulated. Аs results of this study, different strategies are defined by considering the preferences of the vehicle owners and the conditions of the vehicle; thereby the agents autonomously bid behalf of their user in order to automate the process of charging.

  • 239. Collange, Denis
    et al.
    Mahdi, Hajji
    Shaikh, Junaid
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Fiedler, Markus
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Arlos, Patrik
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    User Impatience and Network Performance2012Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this work, we analyze from passive measurements the correlations between the user-induced interruptions of TCP connections and different end-to-end performance metrics. The aim of this study is to assess the possibility for a network operator to take into account the customers' experience for network monitoring. We first observe that the usual connection-level performance metrics of the interrupted connections are not very different, and sometimes better than those of normal connections. However, the request-level performance metrics show stronger correlations between the interruption rates and the network quality-of-service. Furthermore, we show that the user impatience could also be used to characterize the relative sensitivity of data applications to various network performance metrics.

  • 240.
    Cortes, Christoffer
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Krauser, Adam
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Android: Resource Consumption in Native and Web Applications2013Självständigt arbete på grundnivå (kandidatexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    There is an ongoing debate by people in the industry whether to make native or web applications. These discussions mostly surround issues about development costs, user experience and capabilities. Another aspect of this debate is the fact that mobile devices have varying hardware specifications which is another factor to consider when making this decision. What we want to shed some light on is how performance is affected on the device when using these two different approaches of application development. The use of CPU/RAM and Energy is our primary concern and in our experiment we measure these values on two similar applications where one uses Nested Layouts and the other a WebView. The experiment was made on three different devices with varying specifications. What we found was that Web applications have a bigger impact on overall performance and because of this use more battery. While the debate certainly won't come to a close with results they are conclusive when it comes to the topic of performance and will be of value to developers who are concerned about it.

  • 241.
    Cui, Jun
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Query Expansion Research and Application in Search Engine Based on Concepts Lattice2009Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Formal concept analysis is increasingly applied to query expansion and data mining problems. In this paper I analyze and compare the current concept lattice construction algorithm, and choose iPred and Border algorithms to adapt for query expansion. After I adapt two concept lattice construction algorithms, I apply these four algorithms on one query expansion prototype system. The calculation time for four algorithms are recorded and analyzed. The result of adapted algorithms is good. Moreover I find the efficiency of concept lattice construction is not consistent with complex analysis result. In stead, it is high depend on the structure of data set, which is data source of concept lattice.

  • 242.
    Czynszak, Szymon
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Decoding algorithms of Reed-Solomon code2011Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Reed-Solomon code is nowadays broadly used in many fields of data transmission. Using of error correction codes is divided into two main operations: information coding before sending information into communication channel and decoding received information at the other side. There are vast of decoding algorithms of Reed-Solomon codes, which have specific features. There is needed knowledge of features of algorithms to choose correct algorithm which satisfies requirements of system. There are evaluated cyclic decoding algorithm, Peterson-Gorenstein-Zierler algorithm, Berlekamp-Massey algorithm, Sugiyama algorithm with erasures and without erasures and Guruswami-Sudan algorithm. There was done implementation of algorithms in software and in hardware. Simulation of implemented algorithms was performed. Algorithms were evaluated and there were proposed methods to improve their work.

  • 243.
    Dahlskog, Steve
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Digital Game Competence: Literacy or Repertoire?2011Självständigt arbete på avancerad nivå (magisterexamen)Studentuppsats (Examensarbete)
    Abstract [sv]

    Dagens brukare av datorsystem bär med sig en annan förståelse och förmåga att använda datorsystem och programvara än tidigare. Denna annorlunda förståelse finns genom bruket av andra plattformar än traditionella PC med den s.k. skrivbordsmetaforen (t.ex. Windows eller Mac OS). Exempel på andra plattformar är iPhone, surfplattor, spelkonsoller etc. Eftersom denna typ av brukare är van vid andra former är det intressant hur dessa brukare lär sig använda datorsystem och programvara. Inom ramen för uppsatsen undersöks vilka lärsituationer erfarna användare går genom vid bruket av programvara för underhållning. Flertalet av brukarna i fallstudien faller tillbaka på kognitiva schema för att lösa problem de ställs inför. Många gånger är dessa kognitiva schema olämpliga för effektivt lösande av problemen. En liknelse för användningen av ett kognitivt schema är att brukaren går in på en lunchrestaurang med självservering men prompt förväntar sig en restaurang med hovmästare, kypare och meny. Vissa brukare går till och med så långt i liknelsen att de går ut ur (den bildliga) restaurangen och in i igen för att pröva om någon hovmästare märker dem denna gång.

  • 244.
    Daneshzadeh, Fatemeh
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Nassergivehchy, Ali
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Using personas and scenarios in designing for an IPTV solution2010Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    In this research, we focused on developing personas and scenarios in designing a PC Portal for IPTV solution. We employed personas to consider users and their context of use when designing for the system. Different studies have been conducted on the subject of using personas and scenarios in design projects. Some of them show that using personas have a positive effect in the outcome of the design in particular contexts. Other studies, however, suggest that designers have difficulties when using personas in their design process. The underlying cause of these problems might refer to shortcomings in construction of suitable personas, or how to use them throughout the design process. We performed a literature review on personas and scenarios, their advantages, and, how to develop them. Then, we developed personas and scenarios for IPTV problem domain and to base our personas on user study results, we used questionnaire survey and interviews to acquire knowledge about the users. We proposed a design solution and developed a prototype based on elaborated personas and scenarios to evaluate our findings. We argued different challenges that we faced while using personas and scenarios. We illustrated how graphical user interfaces can be developed to satisfy multiple personas by providing the users with different representations of the same information. We also argued why the area of personalized television needs more attention from CHI community and why people are becoming more interested in personalized TV viewing experiences. Elaborated personas and scenarios helped us focus more on users and their context. This could not be easily achieved without rendering the raw data from user studies into personas and scenarios.

  • 245.
    Dappiti, Ramana Reddy
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Thalluri, Mohan Krishna
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Brownian Dynamic Simulation to Predict the Stock Market Price2009Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [sv]

    Prediction of stock markets has been the research interest of many scientists around the world. Speculators who wish to make a “quick buck” as well as economists who wish to predict crashes, anyone in the financial industry has an interest in predicting what stock prices are likely to be. Clearly, there is no model which can accurately predict stock prices; else markets would be absolutely perfect! However, the problem is pertinent and any improvement in the accuracy of prediction improves the state of financial markets today. This forms the broad motivation of our study.

  • 246.
    Davidsson, Paul
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Gustafsson Friberger, Marie
    Holmgren, Johan
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Jacobsson, Andreas
    Persson, Jan A.
    Agreement Technologies for Supporting the Planning and Execution of Transports2013Ingår i: Agreement Technologies, Law, Governance and Technology Series / [ed] Ossowski, Sascha, Dordrecht: Springer Netherlands , 2013, s. 533-547Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    The use of agreement technologies in the planning and execution of goods transports is analyzed. We have previously suggested an approach called Plug and Play Transport Chain Management (PnP TCM) that provides agent-based support for key tasks, such as, finding the best sequence of transport services for a particular goods transport, monitoring the execution of the transport, and managing the interaction between the involved actors. In this paper we analyze five agreement technologies in the context of PnP TCM, i.e., semantics, norms, organizations, argumentation and negotiation, and trust. We conclude that all five technologies play a critical role in the realization of PnP TCM.

  • 247.
    Davidsson, Paul
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Gustafsson Friberger, Marie
    Lavesson, Niklas
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Persson, Jan
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Towards a Prediction Model for People Movements in Urban Areas2013Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this work is to develop a new type of service for predicting and communicating urban activity. This service provides short-term predictions (hours to days), which can be used as a basis for different types of resource allocation and planning, e.g. concerning public transport, personnel, or marketing. The core of the service consists of a forecasting engine that based on a prediction model processes data on different levels of detail and from various providers. This paper explores the requirements and features of the forecast engine. We conclude that agent-based modeling seems as the most promising approach to meet these requirements. Finally, some examples of potential applications are described along with analyses of scientific and engineering issues that need to be addressed.

  • 248.
    Davidsson, Paul
    et al.
    Blekinge Tekniska Högskola, Sektionen för datavetenskap och kommunikation.
    Hagelbäck, Johan
    Travelstart Nordic, SWE.
    Svensson, Kenny
    Ericsson AB, SWE.
    Comparing Approaches to Predict Transmembrane Domains in Protein Sequences2005Konferensbidrag (Refereegranskat)
    Abstract [en]

    There are today several systems for predicting transmembrane domains in membrane protein sequences. As they are based on different classifiers as well as different pre- and post-processing techniques, it is very difficult to evaluate the performance of the particular classifier used. We have developed a system called MemMiC for predicting transmembrane domains in protein sequences with the possibility to choose between different approaches to pre- and post-processing as well as different classifiers. Therefore it is possible to compare the performance of each classifier in a certain environment as well as the different approaches to pre- and post-processing. We have demonstrated the usefulness of MemMiC in a set of experiments, which shows, e.g., that the performance of a classifier is very dependent on which pre- and post-processing techniques are used.

  • 249. Davidsson, Paul
    et al.
    Holmgren, Johan
    Persson, Jan A.
    Jacobsson, Andreas
    Plug and Play Transport Chain Management: Agent-Based Support to the Planning and Execution of Transports2011Ingår i: e-Business and Telecommunications, Communications in Computer and Information Science / [ed] Obaidat, Mohammad S.; Filipe, Joaquim, Berlin Heidelberg: Springer , 2011, s. 139-155Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    A novel approach to efficiently plan and execute effective transport solutions is presented. It provides agent-based support for key tasks, such as, finding the best sequence of transport services for a particular goods transport, monitoring the execution of the transport, as well as the interaction between the involved actors. The approach is based on the FREIGHTWISE framework in which a minimal set of information packages is defined. The purpose is to capture all the information that needs to be communicated between the actors involved in a transport, such as, transport users, transport providers, and infrastructure managers, during the complete process from planning to termination. The approach is inspired by the concepts of virtual enterprises and breeding environments. We analyse the requirements of such an approach and describe a multi-agent system architecture meeting these requirements.

  • 250. Davidsson, Paul
    et al.
    Jacobsson, Andreas
    Towards norm-governed behavior in virtual enterprises2009Ingår i: Studies in Computational Intelligence, ISSN 1860-949X, E-ISSN 1860-9503, Vol. 167, s. 35-55Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    An important application of intelligent agents on the World Wide Web is to support Business to Business (B2B) e-commerce, such as, virtual enterprises. A virtual enterprise can be described as a temporary alliance of enterprises that come together to share skills or core competencies and re sources in order to better respond to business opportunities, and whose coop eration is supported by computer networks. In order to ensure sound collab oration, it is important that the actors involved, as well as the software repre senting the actors such as intelligent agents, act according to the explicit and implicit rules, or norms, that the participating enterprises have agreed upon. The purpose of this article is to explore how norm-governed behavior can be achieved in the context of virtual enterprises. We analyse a number of formal models of both artificial societies and normative systems, and compare and try to align them with a formal model of agent-supported virtual enterprises. A general observation is that the models analysed are not concordant with each other and therefore require further alignment. It is concluded that the in troduction of different types of norms on different levels can support sound collaboration in virtual enterprises. Moreover, the deployment of norm de fender and promoter functionality is argued to ensure norm compliance and impose punishments of norm violations. Finally, a number of additions that may enrich the norm-focused models are suggested.

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