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  • 4751.
    Yang, Shun
    Blekinge Institute of Technology, School of Engineering.
    Modelling and control of a Buck converter2011Independent thesis Basic level (degree of Bachelor)Student thesis
    Abstract [en]

    DC/DC buck converters are cascaded in order to generate proper load voltages. Rectified line voltage is normally converted to 48V, which then, by a bus voltage regulating converter also called the line conditioner converter, is converted to the bus voltage, e.g. 12V. A polynomial controller converter transforms the 12V into to a suitable load voltage, a fraction of or some few voltages. All cascaded converters are individually controlled in order to keep the output voltage stable constant. In this presentation focusing on the polynomial controller converter implemented as Ericsson’s buck converter BMR450. In this paper modeling, discretization and control of a simple Buck converter is presented. For the given DC-DC-Converter-Ericsson BMR 450 series, analyzing the disturbance properties of a second order buck converter controllers by a polynomial controller. The project is performed in Matlab and Simulink. The controller properties are evaluated for measurement noise, EMC noise and for parameter changes.

  • 4752.
    Yang, Xin Yu
    Blekinge Institute of Technology, School of Engineering.
    When Computers Can Discuss Shape Properties with Each Other2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    A novel idea for perception of object surfaces is presented by so called "shape descriptors". Such idea is as an abstract level to represent the object surface by some real numbers. It has the similar idea like as the Fourier coefficients of mapping a function f(x) to frequency domain by Fourier transform. The main goal of this thesis is to define some of the key issues in understanding of an object shape and also to find a modeling methodology to create the "shape descriptors". The modeling methodology is designed based on a variational interpolation technique. Such technique is used to generate a group of variational implicit functions with help of radial basis functions. In our modeling methodology, we randomly choose some reference points on a set of related concentric spheres around a 3D point cloud data as known values in variational implicit functions. The "shape descriptors" are found from these implicit functions implementing LU decomposition. We show that the "shape descriptors" are invariant to size and positioning (rotation and translation) changes of a shape and they are also effective tools for matching of two similar objects surfaces.

  • 4753.
    Yao, Yong
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    A Software Framework for Prioritized Spectrum Access in Heterogeneous Cognitive Radio Networks2014Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Today, the radio spectrum is rarely fully utilized. This problem is valid in more domains, e.g., time, frequency and geographical location. To provide an efficient utilization of the radio spectrum, the Cognitive Radio Networks (CRNs) have been advanced. The key idea is to open up the licensed spectrum to unlicensed users, thus allowing them to use the so-called spectrum opportunities as long as they do not harmfully interfere with licensed users. An important focus is laid on the limitation of previously reported research efforts, which is due to the limited consideration of the problem of competition among unlicensed users for spectrum access in heterogeneous CRNs. A software framework is introduced, which is called PRioritized Opportunistic spectrum Access System (PROAS). In PROAS, the heterogeneity aspects of CRNs are specifically expressed in terms of cross-layer design and various wireless technologies. By considering factors like ease of implementation and efficiency of control, PROAS provides priority scheduling based solutions to alleviate the competition problem of unlicensed users in heterogenous CRNs. The advanced solutions include theoretical models, numerical analysis and experimental simulations for performance evaluation. By using PROAS, three particular CRN models are studied, which are based on ad-hoc, mesh-network and cellular-network technologies. The reported results show that PROAS has the ability to bridge the gap between research results and the practical implementation of CRNs.

  • 4754.
    Yao, Yong
    Blekinge Institute of Technology, School of Computing.
    A Spectrum Decision Support System for Cognitive Radio Networks2012Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

    Cognitive Radio Networks (CRNs) offer a promising capability of alleviating the problem of spectrum insufficiency. In CRNs, the licensed spectrum channels are either exclusively reserved for licensed users or temporarily used by unlicensed users. The requirement for unlicensed users is to not harmfully impair the licensed users transmissions. Because of this, the unlicensed users must solve the task to decide which available channels should be selected. The selection process is often referred to as spectrum decision, with the aim to optimize the transmission performance of unlicensed users. A support system for CRNs is introduced, which is called Spectrum Decision Support System (SDSS). SDSS provides an intelligent spectrum decision strategy that integrates different decision making algorithms and takes into account various channel characterization parameters. The objective is to develop a scientific framework for decision making in CRNs, which involve theoretical analysis, simulation evaluation and practical implementation. Three important components of SDSS are discussed: 1) setting up an overlay decision maker, 2) prediction based spectrum decision strategy and 3) queuing modeling of CRNs. The reported results indicate the feasibility of the suggested algorithms.

  • 4755. Yao, Yong
    et al.
    Erman, David
    PlanetLab Automatic Control System2010Conference paper (Refereed)
    Abstract [en]

    PlanetLab provides a global scale environment for network research. It consists of numerous controllable computer nodes. However, due to that these nodes are deployed in various network domains, there exist experimental issues, regarding network latency, resource utilization, and unpredictable behaviors of nodes. Experimenters need to pay much attention to manually adjusting their selected nodes during the whole experimental process. PLACS is a novel tool system based on PlanetLab, and composed of node selection node management. It can intelligently and automatically coordinate the involved elements, including PlanetLab nodes, experimental programs and experimenter requirements. In this article, the corresponding mechanism functionalities and implementation designs for development are presented.

  • 4756. Yao, Yong
    et al.
    Erman, David
    Popescu, Adrian
    Spectrum Decision for Cognitive Radio Networks2011Conference paper (Refereed)
    Abstract [en]

    Cognitive Radio Networks (CRNs) are a key technology suggested to be part of 4G and beyond. The fundamental concept is to let Secondary Users (SUs) have temporal free access to spectrum bands not occupied by Primary Users (PUs). Since SUs are not allowed to cause harmful interference to PUs, SUs need to select the most available spectrum bands for access, also known as spectrum decision. In the paper, we suggest a middleware called Spectrum Decision Support System (SDSS) abstractly illustrated. The goal of SDSS is to combine the different decision methods together and to make intelligent band selection based upon partial characterizations of CRNs

  • 4757.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, School of Computing.
    Ngoga, Said Rutabayiro
    Blekinge Institute of Technology, School of Computing.
    Erman, David
    Blekinge Institute of Technology, School of Computing.
    Popescu, Adrian
    Blekinge Institute of Technology, School of Computing.
    Competition-Based Channel Selection for Cognitive Radio Networks2012Conference paper (Refereed)
    Abstract [en]

    In cognitive radio networks, unlicensed users need to learn from environmental changes. This is a process that can be done in a cooperative or non-cooperative manner. Due to the competition for channel utilization among unlicensed users, the non-cooperative approach may lead to overcrowding in the available channels. This paper is about a fuzzy-logic based decision making algorithm for competition-based channel selection. The underlying decision criterion integrates both the statistics of licensed users' channel occupancy and the competition level of unlicensed users. By using such an algorithm, the unlicensed user competitors can achieve an efficient sharing of the available channels. Simulation results are reported to demonstrate the performance and effectiveness of our suggested algorithm.

  • 4758.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, School of Computing.
    Ngoga, Said Rutabayiro
    Blekinge Institute of Technology, School of Computing.
    Erman, David
    Blekinge Institute of Technology, School of Computing.
    Popescu, Adrian
    Blekinge Institute of Technology, School of Computing.
    Performance of Cognitive Radio Spectrum Access with Intra- and Inter-Handoff2012Conference paper (Refereed)
    Abstract [en]

    Opportunistic spectrum access (OSA) is a technology that allows unlicensed users to access spectrum holes and to provide so efficient use of radio resources. Most of the studies done on OSA focus on the situation when the unlicensed user performs the spectrum handoff only within a single cognitive radio network (so-called intra-handoff). In this paper, we consider the users (licensed or unlicensed) to be able to do inter-handoff among different cognitive radio cells as well. The cells provide priority to inter-handoff users. By considering multiple cells being in steady-state, the arrival rates of inter-handoff users are determined. We study the OSA performance of unlicensed users under both intra- and inter-handoff schemes, with respect to the blocking and forced-termination probabilities of unlicensed users as well as the unlicensed user service-completion and inter-handoff throughputs. Our Markov chain based numerical analysis is validated by simulation experiments.

  • 4759.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, School of Computing.
    Ngoga, Said Rutabayiro
    Popescu, Adrian
    Blekinge Institute of Technology, School of Computing.
    A System for Spectrum Decision in Cognitive Radio Networks2012Conference paper (Refereed)
    Abstract [en]

    In Cognitive Radio (CR) networks, licensed radio channels are allowed to be used by Secondary Users (SUs) as long as SUs do not harmfully impair the transmission of Primary Users (PUs). Therefore, a crucial task for SUs is to decide which available channel should be selected, the so-called spectrum decision. To provide intelligent spectrum decision strategy to SUs, we suggest a system called Spectrum Decision Support System (SDSS). SDSS takes into account both heterogeneity aspects and interoperability requirements of CR networks. By this, SDSS is capable of jointly considering various channel characterizations and different decision making algorithms for doing spectrum decision. The paper is reporting the SDSS architecture as well as the related work-in-progress.

  • 4760.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Popescu, Adrian
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    On Energy Consumption in Mobile Multimedia Networks with OpenFlow Switch2016In: 2016 INTERNATIONAL CONFERENCE ON COMMUNICATIONS (COMM 2016), IEEE, 2016, p. 309-312Conference paper (Refereed)
    Abstract [en]

    In mobile multimedia networks, the video flow usually operates in an end-to-end manner from Head-End to mobile terminals. However, measuring the energy consumption associated with a video flow is a sophisticated process due to the complexity related to this. In the paper, a theoretical measurement approach is suggested to estimate the energy consumption of a video flow through mobile multimedia networks enhanced with the support of OpenFlow switch. Two different power models are built up to compute the traffic related energy consumption at the network element side. The numerical derivation of these two theoretical models is presented.

  • 4761.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, School of Computing.
    Popescu, Alexandru
    Blekinge Institute of Technology, School of Computing.
    Ngoga, Said Rubatayiro
    Blekinge Institute of Technology, School of Computing.
    Popescu, Adrian
    Blekinge Institute of Technology, School of Computing.
    On Prioritized Spectrum Access in Cognitive Radio Networks with Imperfect Sensing2013Conference paper (Refereed)
    Abstract [en]

    Cognitive Radio networks allow the unlicensed users to share the available spectrum opportunities. However, this demands for solving the problem of contention among multiple unlicensed user packets for transmission. In our paper, we consider the Opportunistic Spectrum Access model for packet transmission between two unlicensed users. We suggest a priority scheme for a unlicensed user to concurrently transmit different types of packets. Our scheme reserves a fixed number of queueing places in the buffer for the prioritized packets. We study the transmission performance under both the priority scheme and imperfect spectrum sensing, with respect to the blocking probabilities, average transmission delay and transmission throughput of unlicensed users packets. The Markov chain based numerical analysis is validated by simulation experiments. Our results show that the suggested priority scheme is able to enhance transmission throughput of unlicensed users packets, together with significant decreased average transmission delay and minor decreased total transmission throughput.

  • 4762.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Popescu, Alexandru
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Popescu, Adrian
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    On Fuzzy Logic-Based Channel Selection in Cognitive Radio Networks2014In: Software-Defined and Cognitive Radio Technologies for Dynamic Spectrum Management / [ed] Kaabouch, Naima; Hu, Wen-Chen, Hershey, PA 17033, USA: IGI-Global , 2014Chapter in book (Refereed)
    Abstract [en]

    Cognitive radio networks are a new technology based on which unlicensed users are allowed access to licensed spectrum under the condition that the interference perceived by licensed users is minimal. That means unlicensed users need to learn from environmental changes and to take appropriate decisions regarding the access to the radio channel. This is a process that can be done by unlicensed users in a cooperative or non-cooperative way. Whereas the non-cooperative algorithms are risky with regard to performance, the cooperative algorithms have the capability to provide better performance. Our paper reports therefore a new fuzzy logic based decision making algorithm for channel selection. The underlying decision criterion considers statistics of licensed users channel occupancy as well as information about the competition level of unlicensed users. Our theoretical studies indicate that the unlicensed users can obtain an efficient sharing of the available channels. Simulation results are reported to demonstrate the performance and effectiveness of the suggested algorithm.

  • 4763.
    Yao, Yong
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Popescu, Alexandru
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    Popescu, Adrian
    Blekinge Institute of Technology, Faculty of Computing, Department of Communication Systems.
    On prioritised opportunistic spectrum access in cognitive radio cellular networks2015In: European transactions on telecommunications, ISSN 1124-318X, E-ISSN 2161-3915, Vol. 27, no 2, p. 294-310Article in journal (Refereed)
    Abstract [en]

    Cognitive radio (CR) networks allow secondary users (SUs) to opportunistically access licensed spectrum, thus providing efficient use of radio resources. Different studies carried out on CR networks have focused on the procedure of spectrum handoff of SUs such as the data transmission in a communication that can be carried out in different channels. In this paper, we consider cellular networks enhanced with facilities for CR communication where a user with a call in progress moves across neighbouring cells, that is, the so-called inter-cell handoff. Our model assumes that the cell gives priority to inter-cell handoff calls over the calls originating within it. A finite queue is used in every cell for SUs, and a fixed number of buffer slots are reserved for the inter-handoff SU calls. With these considerations, we study the transmission performance of SUs by using Markov chains-based modelling approach. The numerical analysis is validated by simulation experiments. We also suggest a fuzzy logic-based hybrid decision-making algorithm to select the best solution for inter-handoff prioritisation. The goal is to optimise the transmission performance of SUs by leveraging their requirements on service completion throughput and waiting time in each cell. Copyright © 2014 John Wiley & Sons, Ltd.

  • 4764.
    Yasam, Venkata Sudheer Kumar Reddy
    Blekinge Institute of Technology, School of Computing.
    An Optimized Representation for Dynamic k-ary Cardinal Trees2009Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Trees are one of the most fundamental structures in computer science. Standard pointer-based representations consume a significant amount of space while only supporting a small set of navigational operations. Succinct data structures have been developed to overcome these difficulties. A succinct data structure for an object from a given class of objects occupies space close to the information-theoretic lower-bound for representing an object from the class, while supporting the required operations on the object efficiently. In this thesis we consider representing trees succinctly. Various succinct representations have been designed for representing different classes of trees, namely, ordinal trees, cardinal trees and labelled trees. Barring a few, most of these representations are static in that they do not support inserting and deleting nodes. We consider succinct representations for cardinal trees that also support updates (insertions and deletions), i.e., dynamic cardinal trees. A cardinal tree of degree k, also referred to as a k-ary cardinal tree or simply a k-ary tree is a tree where each node has place for up to k children with labels from 1 to k. The information-theoretic lower bound for representing a k-ary cardinal tree on n nodes is roughly (2n+n log k) bits. Representations that take (2n+n log k+ o(n log k ) ) bits have been designed that support basic navigations operations like finding the parent, i-th child, child-labeled j, size of a subtree etc. in constant time. But these could not support updates efficiently. The only known succinct dynamic representation was given by Diego, who gave a structure that still uses (2n+n log k+o(n log k ) ) bits and supports basic navigational operations in O((log k+log log n) ) time, and updates in O((log k + log log n)(1+log k /log (log k + log log n))) amortized time. We improve the times for the operations without increasing the space complexity, for the case when k is reasonably small compared to n. In particular, when k=(O(√(log n ))) our representation supports all the navigational operations in constant time while supporting updates in O(√(log log n )) amortized time.

  • 4765.
    Yasar, Fatma Gunseli
    et al.
    Izmir Katip Celebi Universitesi, TUR.
    Kusetogullari, Hüseyin
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Underwater human body detection using computer vision algorithms2018In: 26th IEEE Signal Processing and Communications Applications Conference, SIU 2018, Institute of Electrical and Electronics Engineers Inc. , 2018, p. 1-4Conference paper (Refereed)
    Abstract [en]

    The number of studies to ensure the security when life-threatening unexpected events are encountered increases. Increasing of time spent under the water can cause the death of people. Thus, people who are in a risk of suffocation in the water must be found for early intervention and this process must be quick. The main contribution of this study is to detect and to track the people under the water quickly. Thresholding, Background Subtraction, Interframe Difference and Foreground Detection methods have been applied to create the silhouette of the people under the water. These methods have been demonstrated on videos which are found from internet. © 2018 IEEE.

  • 4766.
    Yasin, Affan
    et al.
    Blekinge Institute of Technology, School of Computing.
    Hasnain, Muhammad Ijlal
    Blekinge Institute of Technology, School of Computing.
    On the Quality of Grey Literature and its use in Information Synthesis during Systematic Literature Reviews2012Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Context: The Internet has become a vital channel for disseminating and accessing scientific literature for both the academic and industrial research needs. Nowadays, everyone has wide access to scientific literature repositories, which comprise of both “white” and “Grey” literature. The “Grey” literature, as opposed to “white” literature, is non-peer reviewed scientific information that is not available using commercial information sources such as IEEE or ACM. A large number of software engineering researchers are undertaking systematic literature reviews (SLRs) to investigate empirical evidence in software engineering. The key reason to include grey literature during information synthesis is to minimize the risk of any bias in the publication. Using the state of the art non-commercial databases that index information, the researchers can make the rigorous process of searching empirical studies in SLRs easier. This study explains the evidence of Grey literature while performing synthesis in Systematic Literature Reviews. Objectives: The goals of this thesis work are, 1. To identify the extent of usage of Grey Literature in synthesis during systematic literature reviews. 2. To investigate if non-commercial information sources primarily Google Scholar are sufficient for retrieving primary studies for SLRs. Methods: The work consists of a systematic literature review of SLRs and is a tertiary study and meta-analysis. The systematic literature review was conducted on 138 SLRs’ published through 2003 until 2012 (June). The article sources used are IEEEXplore, ACM Digital Library, Springer-Link and Science Direct. Results: For each of the selected article sources such as ACM, IEEEXplore, Springer-link and Science Direct, we have presented results, which describe the extent of the usage of Grey literature. The qualitative results discuss various strategies for systematic evaluation of the Grey literature during systematic literature review. The quantitative results comprise of charts and tables, showing the extent of Grey literature usage. The results from analysis of Google Scholar database describe the total number of primary studies that we are able to find using only Google Scholar database. Conclusion: From the analysis of 138 Systematic Literature Reviews (SLRs’), we conclude that the evidence of Grey literature in SLRs is around 9%. The percentage of Grey literature sources used in information synthesis sections of SLRs is around 93.2%. We were able to retrieve around 96 % of primary studies using Google Scholar database. We conclude that Google Scholar can be a choice for retrieving published studies however; it lacks detailed search options to target wider pool of articles. We also conclude that Grey literature is widely available in this age of information. We have provided guidelines in the form of strategies for systematic evaluation of Grey literature.

  • 4767.
    Yates, Andrew
    et al.
    Max Planck Institut für Informatik, DEU.
    Unterkalmsteiner, Michael
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Replicating relevance-ranked synonym discovery in a new language and domain2019In: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Springer Verlag , 2019, Vol. 11437, p. 429-442Conference paper (Refereed)
    Abstract [en]

    Domain-specific synonyms occur in many specialized search tasks, such as when searching medical documents, legal documents, and software engineering artifacts. We replicate prior work on ranking domain-specific synonyms in the consumer health domain by applying the approach to a new language and domain: identifying Swedish language synonyms in the building construction domain. We chose this setting because identifying synonyms in this domain is helpful for downstream systems, where different users may query for documents (e.g., engineering requirements) using different terminology. We consider two new features inspired by the change in language and methodological advances since the prior work’s publication. An evaluation using data from the building construction domain supports the finding from the prior work that synonym discovery is best approached as a learning to rank task in which a human editor views ranked synonym candidates in order to construct a domain-specific thesaurus. We additionally find that FastText embeddings alone provide a strong baseline, though they do not perform as well as the strongest learning to rank method. Finally, we analyze the performance of individual features and the differences in the domains. © Springer Nature Switzerland AG 2019.

  • 4768.
    Yavariabdi, Amir
    et al.
    Karatay Üniversitesi, TUR.
    Kusetogullari, Hüseyin
    Blekinge Institute of Technology, Faculty of Computing, Department of Computer Science and Engineering.
    Mendi, Engin
    Karatay Üniversitesi, TUR.
    Karabatak, Begum
    Turkcell, Nicosia, CYP.
    Unsupervised Change Detection using Thin Cloud-Contaminated Landsat Images2018In: 9th International Conference on Intelligent Systems 2018: Theory, Research and Innovation in Applications, IS 2018 - Proceedings / [ed] JardimGoncalves, R; Mendonca, JP; Jotsov, V; Marques, M; Martins, J; Bierwolf, R, Institute of Electrical and Electronics Engineers Inc. , 2018, p. 21-25Conference paper (Refereed)
    Abstract [en]

    In this paper, a novel unsupervised change detection method is proposed to automatically detect changes between two cloud-contaminated Landsat images. To achieve this, firstly, a photometric invariants technique with Stationary Wavelet Transform (SWT) are applied to input images to decrease the influence of cloud and noise artifacts in the change detection process. Then, mean shift image filtering is employed on the sub-band difference images, generated via image differencing technique, to smooth the images. Next, multiple binary change detection masks are obtained by partitioning the pixels in each of the smoothed sub-band difference images into two clusters using Fuzzy c-means (FCM). Finally, the binary masks are fused using Markov Random Field (MRF) to generate the final solution. Experiments on both semi-simulated and real data sets show the effectiveness and robustness of the proposed change detection method in noisy and cloud-contaminated Landsat images. © 2018 IEEE.

  • 4769.
    Yelleswarapu, Mahesh Chandra
    Blekinge Institute of Technology, School of Computing.
    An Assessment of the Usability Quality Attribute in Open Source Software2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Usability is one of the important quality attributes. Open source software products are well known for their efficiency and effectiveness. Lack of usability in OSS (Open Source Software) products will result in poor usage of the product. In OSS development there is no usability team, and one could therefore expect that the usability would be low for these products. In order to find out if this was really the case we made a usability evaluation using a questionnaire for four OSS products. The questionnaire was based on a review of existing literature. This questionnaire was presented to 17 people who are working with open source products. This evaluation showed that the overall usability was above average for all the four products. It seems, however, that the lack of a usability team has made the OSS products less easy to use for inexperienced users. Based on the responses to questionnaire and a literature review, a set of guidelines and hints for increasing the usability of OSS products was defined.

  • 4770. Yeoh, Phee
    et al.
    Elkashlan, Maged
    Duong, Quang Trung
    Blekinge Institute of Technology, School of Computing.
    Yang, Nan
    Da Costa, Daniel
    Transmit antenna selection in cognitive relay networks with Nakagami-m fading2013Conference paper (Refereed)
    Abstract [en]

    We examine the impact of multiple primary receivers on cognitive multiple-input multiple-output (MIMO) relay networks with underlay spectrum sharing. For such a network, we propose transmit antenna selection with receive maximal-ratio combining (TAS/MRC) as an interference-aware design to satisfy the power constraints in the primary and secondary networks. To demonstrate this, we derive new closed-form expressions for the exact and asymptotic outage probability with TAS/MRC and decode-and-forward (DF) relaying over independent Nakagami-m fading channels in the primary and secondary networks. Several important design insights are reached. We find that the TAS/MRC strategy achieves a full diversity gain when the transmit power in the secondary network is proportional to the peak interference power in the primary network. Furthermore, we highlight that the diversity-multiplexing tradeoff (DMT) of TAS/MRC is independent of the primary network and entirely dependent on the secondary network.

  • 4771. Yeoh, Phee Lep
    et al.
    Elkashlan, Maged
    Duong, Quang Trung
    Blekinge Institute of Technology, School of Computing.
    Yang, Nan
    Leung, Cyril
    Cognitive MIMO relaying in Nakagami-m fading2013Conference paper (Refereed)
    Abstract [en]

    We propose transmit antenna selection with receive maximal-ratio combining (TAS/MRC) as an effective approach to reduce interference in cognitive multiple-input multiple-output (MIMO) relay networks. To demonstrate this, we derive new closed-form expressions for the exact and asymptotic outage probability of TAS/MRC with multiple antennas at the primary and secondary users. We consider underlay spectrum sharing where the secondary users (SUs) transmit in the presence of multiple primary users (PUs). We consider independent Nakagami-m fading in both the primary and secondary networks. Several important design insights are revealed. We find that TAS/MRC achieves a full diversity when the transmit power at the SUs is proportional to the peak interference power at the PUs. Furthermore, we highlight that this diversity gain is completely independent of the number of antennas at the PUs.

  • 4772. Ygge, Fredrik
    Market-Oriented Programming and its Application to Power Load Management1998Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Market-oriented programming is a new approach to design and implementation of resource allocation mechanisms in computer systems. It has its roots in different disciplines, such as economics and computer science (in particular the area of multi-agent systems. This thesis is divided into two different parts, focusing on: 1) central foundations and mechanisms of market-oriented programming, and 2) the use of market-oriented programming in practical applications. Market-oriented programming is seen as a programming paradigm based on abstractions such as prices and demands. Concepts, terminology and theory from micro-economics form the foundations of the paradigm. Central aspects of these foundations are investigated and some new insights are presented. Furthermore, some relations between standard optimization/resource allocation approaches and markets are described, and novel theorems are introduced. A plethora of algorithms (some stemming from mathematical optimization and numerical analysis, and some new) for the main computational problem of market-oriented programming -- the computation of general equilibrium -- are described, analyzed and compared. Some issues of self-interested agents in market-oriented programming are also investigated. A published, and generally recognized, market-oriented approach to the application building climate control is analyzed in some detail. A new approach to this application, based on market-oriented programming, is introduced and shown to be superior to the analyzed approach in many ways. The case study pinpoints a number of potential pitfalls as well as advantages of market-oriented approaches to this and other applications. A second investigated application is power load management, i.e. the management of loads at the customers' side for obtaining more efficient energy systems management. The basis of the application is described and a new market-oriented approach is introduced and analyzed. The approach is shown to have a number of advantages compared to existing approaches to this problem. The main conclusion of the thesis is that there are some potential pitfalls of market-oriented programming, but when used with care it provides a highly natural and efficient means for resource allocation in computer systems.

  • 4773. Ygge, Fredrik
    Power Load Management as a Multi-Commodity Market1997Report (Other academic)
    Abstract [en]

    The current report investigates the application of market-oriented programming to power load management. Power load management (or load management for short) is the management of loads at the customer side in order to manage energy systems more efficiently. As energy systems are very large and heavily distributed (typically including millions of loads in an area covering counties or countries), efficient and conceptually attractive methods are required for making load management successful. This report demonstrates how market-oriented programming can be utilized to meet the above demands.

  • 4774. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Duality in Multi-Commodity Market Computations1997Report (Other academic)
    Abstract [en]

    In search for general equilibrium in multi-commodity markets, price-oriented schemes are normally used. That is, a set of prices (one price for each commodity) is updated until supply meets demand for each commodity. It is well known that in a two-commodity market resource-oriented schemes are conceivable. In this paper we demonstrate the duality between price- and resource-oriented schemes in the general multi-commodity case. We also discuss important properties of the two approaches. In resource-oriented schemes the resource constraint, which says that supply must equal demand, is always fulfilled, implying that at any time the auctioneer can provide a feasible allocation. This is not the case in price-oriented schemes outside market equilibrium. In this paper we introduce a novel any-time algorithm, Proportion, for the price-oriented scheme as well, that allows the auctioneer to deliver a suitable allocation at some deadline (possibly unknown in advance) also before market equilibrium is reached. We also show how the findings for the any-time algorithms can enable more efficient price-oriented markets.

  • 4775. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Duality in Multi-Commodity Market Computations1997Conference paper (Refereed)
  • 4776. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Making a Case for Multi-Agent Systems1997Conference paper (Refereed)
    Abstract [en]

    Multi agent systems (MAS) promise to offer solutions to problems where established, older paradigms fall short. To be able to keep promises, however, in depth studies of advantages and weaknesses of MAS solutions versus conventional ones in practical applications are needed. We offer one such study. Climate control in large buildings is one application area where MAS, and market oriented programming in particular, have been reported to be very successful. We have therefore constructed and implemented a variety of market designs for this problem, as well as different standard control engineering solutions. The paper gives a detailed analysis and comparison, so as to learn about differences between standard versus MAS approaches, and yielding new insights about benefits and limitations of computational markets.

  • 4777. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Making a Case for Multi-Agent Systems1997Report (Other academic)
    Abstract [en]

    Multi-Agent Systems (MAS) promise to offer solutions to problems were established, older paradigms fall short. To be able to keep promises, however, in-depth studies of advantages and weaknesses of MAS solutions versus conventional ones in practical applications are needed. In this paper we offer one such study. Climate control in large buildings is one application area where MAS, and market-oriented programming in particular, have been reported to be very successful. We have therefore constructed and implemented a variety of market designs for this problem, as well as different standard control engineering solutions. This paper gives a detailed analysis and comparison, so as to learn about differences between standard versus MAS approaches, and yielding new insights about benefits and limitations of computational markets.

  • 4778. Ygge, Fredrik
    et al.
    Akkermans, Hans
    On Resource-Oriented Multi-Commodity Market Computations1998Report (Other academic)
    Abstract [en]

    In search for general equilibrium in multi-commodity markets, price-oriented schemes are normally used. That is, a set of prices (one price for each commodity) is updated until supply meets demand for each commodity. In some cases such an approach is very inefficient, and a resource-oriented scheme can be highly competitive. In a resource-oriented scheme the allocations are updated until the market equilibrium is found. It is well known that in a two-commodity market resource-oriented schemes are possible. In this paper we show that resource-oriented algorithms can be used for the general multi-commodity case as well, and present and analyze a specific algorithm. The algorithm has been implemented and some performance properties, for a specific example, are presented.

  • 4779. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Power Load Management as a Computational Market1996Conference paper (Refereed)
    Abstract [en]

    Power load management enables energy utilities to reduce peak loads and thereby save money. Due to the large number of different loads, power load management is a complicated optimization problem. We present a new decentralized approach to this problem by modeling direct load management as a computational market. Our simulation results demonstrate that our approach is very efficient with a superlinear rate of convergence to equilibrium and an excellent scalability, requiring few iterations even when the number of agents is in the order of one thousand. A framework for analysis of this and similar problems is given which shows how nonlinear optimization and numerical mathematics can be exploited to characterize, compare and tailor problem-solving strategies in market-oriented programming.

  • 4780. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Power Load Management as a Computational Market1996Report (Other academic)
    Abstract [en]

    Power load management enables energy utilities to reduce peak loads and thereby save money. Due to the large number of different loads, power load management is a complicated optimization problem. We present a new decentralized approach to this problem by modeling direct load management as a computational market. Our simulation results demonstrate that our approach is very efficient with a superlinear rate of convergence to equilibrium and an excellent scalability, requiring few iterations even when the number of agents is in the order of one thousand. A framework for analysis of this and similar problems is given which shows how nonlinear optimization and numerical mathematics can be exploited to characterize, compare, and tailor problem-solving strategies in market-oriented programming.

  • 4781. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Smart Software as Customer Assistant in Large-Scale Distributed Load Management1997Report (Other academic)
    Abstract [en]

    Advanced information systems present a key enabling technology for innovative customer-oriented services by the utility industry. Real-time and two-way electronic information exchange with the customer over the power grid and other media is now possible. This provides the baseline for a host of new customer services, provided proper advantage is taken of a variety of recent advances in information technology. In this context, we discuss (a) how to engineer knowledge into systems and services, giving rise to smart software and intelligent systems, and (b) how to exploit this practically for novel ways to achieve distributed load management, dealing with thousands of devices simultaneously. A special characteristic of our concept is that the two-way information exchange for load-balancing purposes is based on market mechanisms similar to an auction. This auction is carried out by small smart software programs in devices (such as radiators) that represent and assist the customer. Field experiments with this intelligent and distributed new approach to power load management are currently performed.

  • 4782. Ygge, Fredrik
    et al.
    Akkermans, Hans
    Andersson, Arne
    A Multi-Commodity Market Approach to Power Load Management1998Report (Other academic)
    Abstract [en]

    Power load management is the concept of controlling the loads at the demand side in order to run energy systems more efficiently. Energy systems are inherently highly distributed and contain large number of loads, up to some million. This implies that computationally and conceptually attractive methods are required for this application. In this paper we give two novel theorems for how to decompose general resource allocation problems into markets. We also introduce a novel multi-commodity market design to meet the demands of power load management. The approach is demonstrated to lead to very high quality allocations, and to have a number of advantages compared to current methods.

  • 4783. Ygge, Fredrik
    et al.
    Astor, Eric
    Interacting Intelligent Software Agents in Demand Management1995Conference paper (Refereed)
    Abstract [en]

    Even though distributed computing and two-way communication with the customer is becoming a reality for many energy distribution companies, there is still a need to develop methodologies for more efficient energy management. In this paper we discuss current approaches to demand management, and then present ideas from other areas applied in energy management. We introduce concepts such as computational markets and software agents in this context. In addition, methods entirely based on distributed problem solving to address the computationally hard problems of resource allocation with vast number of clients are described. We also discuss how these methods can be used to perform cost/benefit analysis of demand management.

  • 4784. Ygge, Fredrik
    et al.
    Astor, Eric
    Interacting Intelligent Software Agents in Distribution management1995Report (Other academic)
    Abstract [en]

    Even though distributed computing and two-way communication with the customer is becoming a reality for many energy distribution companies, there still is a need to develop methodologies for more efficient energy management. In this paper we discuss current approaches to demand management, and then present ideas from other areas applied to energy management. We introduce concepts such as computational markets and software agents in this context. In addition, methods entirely based on distributed problem solving to address the computationally hard problems of resource allocation with vast number of clients are described. We also discuss how these methods can be used to perform cost/benefit analysis of demand management.

  • 4785. Ygge, Fredrik
    et al.
    Gustavsson, Rune
    Akkermans, Hans
    HOMEBOTS: Intelligent Agents for Decentralized Load Management1996Conference paper (Refereed)
  • 4786.
    Ying, PuLe
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Fan, LingZhi
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Methods For Test Case Prioritization Based On Test Case Execution History2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Motivation: Test case prioritization can prioritize test cases, optimize the test execution, save time and cost. There are many different methods for test case prioritization, test case prioritization method based on test case execution history is one kind of them. Based on the test case execution history, it’s easier to increase the rate of fault detection, hence we want to do a study about test case prioritization methods based on the test case execution history. Meanwhile, executing the feasible methods to compare the effectiveness of them. For the motivation of the thesis may be regarded as an example for experiencing approach for comparing test case prioritizations based on test case execution history, or as a study case for identifying the suitable methods to use and help improve the effectiveness of the testing process.

    Objectives: The aim of this thesis is to look for a suitable test case prioritization method that can support risk based testing, in which test case execution history is employed as the key criterion of evaluation. For this research, there are three main objectives. First, explore and summarize methods of test case prioritization based on test case history. Next, identify what are differences among the test case prioritization methods. Finally, execute the methods which we selected, and compare the effectiveness of methods.

    Methods: To achieve the first and the second study objectives, a systematic literature review has been conducted using Kitchenham guidelines. To achieve the third study objective, an experiment was conducted following Wohlin guidelines.

    Results: In our thesis: 1) We conducted a systematic literature review and selected 15 relevant literatures. We extracted data of the literatures and then we synthesized the data. We found that the methods have different kinds of inputs, test levels, maturity levels, validation and "automated testing or manual testing". 2) We selected two feasible methods from those 15 literatures, Method 1 is Adaptive test-case prioritization and Method 2 is Similarity-based test quality metric. We executed the methods within 17 test suites. Comparing the result of two methods and non-prioritization, the mean Average Percentage of Defects Found (APFD) of Adaptive test-case prioritization execution result (86.9%) is significantly higher than non-prioritization (51.5%) and Similarity-based test quality metric (47.5%), it means that the Adaptive test-case prioritization has higher effectiveness.

    Conclusion: In our thesis, existing test case prioritization methods based on test case execution history are extracted and listed out through systematic literature review. The summary of them and the description of differences can be available in the thesis. The 15 relevant literatures and the synthesized data may be as a guideline for relevant software researchers or testers. We did the statistical test for the experimental result, we can see two different test case prioritization methods have different effectiveness.

  • 4787.
    Yiran, Zhou
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Yilei, Liu
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    The Challenges and Mitigation Strategies of Using DevOps during Software Development2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 4788.
    Yousefi, Parisa
    et al.
    Blekinge Institute of Technology, School of Computing.
    Yousefi, Pegah
    Blekinge Institute of Technology, School of Computing.
    Cost Justifying Usability a case-study at Ericsson2011Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    In this study we investigate the level of usability and usability issues and the gaps concerning usability activities and the potential users, in a part of charging system products in Ericsson.Also we try identifying the cost-benefit factors, usability brings to this project, in order to attempt 'justifying the cost of usability for this particular product'.

  • 4789.
    Yousuf, Kamran
    Blekinge Institute of Technology, School of Computing.
    Time controlled network traffic shaper2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Network performance metrics such as delay variations and packet loss influence the performance of the network. As a consequence, the performance of applications on the network is also affected as most of the networked applications existing today are very much sensitive to the network performance. Therefore it is of utmost importance to test the intensity of such network level disturbances on the performance of applications. A network traffic shaper/emulator shapes the network traffic in terms of these performance metrics to test such applications in a controlled environment. Most of the traffic shapers existing today give the instantaneous step transition in delay and packet loss on network. In this work, we present time-controlled network traffic shaper, a tool that facilitates testing and experimentation of network traffic through emulation. It focuses on time variant behavior of the traffic shaper. A linear transition of delay and packet loss that is varying with respect to time may fits much better to the real network scenarios instead of an instantaneous step transition in delay and packet loss. This work illustrates the emulation capabilities of time-controlled network traffic shaper and presents its design architecture. Several approaches are analyzed to do the task and one of them is followed to develop the desired architecture of the shaper. The shaper is implemented in a small scenario and is tested to see whether the desired output is achieved or not. The shortfalls in the design of the shaper are also discussed. Results are presented that show the output from the shaper in graphical form. Although the current implementation of the shaper does not provide linear or exponential output but this can be achieved by implementing a configuration setting that is comprised of small transition values that are varying with respect to very small step sizes of time e.g. transitions on milli seconds or micro seconds. The current implementation of the shaper configuration provides the output with a transition of one milli second on every next second.

  • 4790.
    Yu, Liang
    et al.
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Alégroth, Emil
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Chatzipetrou, Panagiota
    Örebro universitet, SWE.
    Gorschek, Tony
    Blekinge Institute of Technology, Faculty of Computing, Department of Software Engineering.
    Utilising CI environment for efficient and effective testing of NFRs2020In: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 117, article id 106199Article in journal (Refereed)
    Abstract [en]

    Context: Continuous integration (CI) is a practice that aims to continuously verify quality aspects of a software intensive system both for functional and non-functional requirements (NFRs). Functional requirements are the inputs of development and can be tested in isolation, utilising either manual or automated tests. In contrast, some NFRs are difficult to test without functionality, for NFRs are often aspects of functionality and express quality aspects. Lacking this testability attribute makes NFR testing complicated and, therefore, underrepresented in industrial practice. However, the emergence of CI has radically affected software development and created new avenues for software quality evaluation and quality information acquisition. Research has, consequently, been devoted to the utilisation of this additional information for more efficient and effective NFR verification. Objective: We aim to identify the state-of-the-art of utilising the CI environment for NFR testing, hereinafter referred to as CI-NFR testing. Method: Through rigorous selection, from an initial set of 747 papers, we identified 47 papers that describe how NFRs are tested in a CI environment. Evidence-based analysis, through coding, is performed on the identified papers in this SLR. Results: Firstly, ten CI approaches are described by the papers selected, each describing different tools and nine different NFRs where reported to be tested. Secondly, although possible, CI-NFR testing is associated with eight challenges that adversely affect its adoption. Thirdly, the identified CI-NFR testing processes are tool-driven, but there is a lack of NFR testing tools that can be used in the CI environment. Finally, we proposed a CI framework for NFRs testing. Conclusion: A synthesised CI framework is proposed for testing various NFRs, and associated CI tools are also mapped. This contribution is valuable as results of the study also show that CI-NFR testing can help improve the quality of NFR testing in practices. © 2019

  • 4791.
    Yusuf, Adewale
    Blekinge Institute of Technology, Faculty of Computing, Department of Creative Technologies.
    Challenges associated with effective task execution in a Virtual Learning Environment: A case study of Graduate Students of a University2017Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Context: In recent years, more and more people have started showing an increasing interest in distance or web-based education. Some of the reasons for this are the improvement in information and communication technology, as well as advancement in computer networking infrastructures. However, although computer technology has played an important role for the development of distance learning management systems, the underlying goal of such systems is the delivery of competitive and qualitative education via the distance learning environment. There have been a number of research studies and investigations in the field of Computer supported collaborative learning. This particular study is focused on the challenges associated with task execution in a distance learning environment as perceived by graduate students at a university.

    Objectives: The main focus or rationale behind this study is to investigate the importance of computer mediated communication tools in a virtual learning environment, as well as the problems facing the teachers or facilitators in their attempt to help learners (students) in the process of task execution, and towards achieving the learning goals in a web-based learning system.

    Methods: The author has adopted a qualitative case study approach. Questionnaires were sent out to some of the graduate students of BTH that participated in the online course under investigation, “Work integrated e-learning”, and some of these students were interviewed as well. Interviews were also conducted with two professors of Informatics and active researchers in distributed or e-learning in a University in Sweden that has had many years of experience in providing distance learning education. The empirical material was then analyzed, using cultural historical activity theory (CHAT) as a theoretical framework

    Results: The results indicate that more communication and collaborative interaction is needed in the context of the studied e-learning management system. The students expected the provision of more video communication through the learning platform. Furthermore, the results show that the learning in the studied web-based environment is centered on the students. 

    Conclusions: The author concludes that in order to diminish the gap that exists between face-to-face learning/teaching and an e-learning environment, there is a need for the designers and facilitators of the e-learning management system to make this platform more interactive. Additionally, the author concludes that the concept of Open start free pace (OSFP) or strict deadlines may need to be introduced into distance learning education in order to solve the challenges facing the teachers and facilitators.  

     

  • 4792.
    Yılmazer, Şafak Enes
    Blekinge Institute of Technology, School of Engineering.
    Integrated Coverage Measurement and Analysis System for Outdoor Coverage WLAN2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Daily usage of Wireless Local Area Networks (WLAN) in business life for specific purposes has became much more critical than before since it is sometimes crucial to have wireless connectivity and seamless roaming around the working environment. In this thesis, steps required in order to design and implement a large scale outdoor IEEE 802.11g WLAN will be shown. This WLAN project has been deployed in north of Sweden and target coverage was an open area consisting of a deep pit mine, connecting roads, workshops, offices, dumps and storage areas. All telecommunications equipment used in this project is from the manufacturer Cisco using centralized solution. The special purpose of this project is to collect and analyze a series of coverage measurement data and correlate this data to predict the coverage area. Linux bash scripting and Gnuplot has been used to analyze coverage data. Finally, WRAP spectrum management and radio planning software has been used in modeling and designing of the whole network.

  • 4793. Zackrisson, Johan
    et al.
    Svahnberg, Charlie
    OpenLabs Security laboratory: The online security experiment platform2008Conference paper (Refereed)
    Abstract [en]

    For experiments to be reproducible, it is important to have a known and controlled environment. This requires isolation from the surroundings. For security experiments, e.g. with hostile software, this is even more important as the experiment can affect the environment in adverse ways. In a normal campus laboratory, isolation can be achieved by network separation. For an online environment, where remote control is essential, separation and isolation are still needed, and therefore the security implications must be considered. In this paper, a way to enable remote experiments is described, where users are given full control over the computer installation. By automating the install procedure and dynamically creating isolated experiment networks, remote users are provided with the tools needed to do experiments in a reproducible and secure environment.

  • 4794. Zackrisson, Johan
    et al.
    Svahnberg, Charlie
    OpenLabs Security Laboratory: The Online Security Experiment Platform2008In: International Journal of Online Engineering, ISSN 1868-1646, E-ISSN 1861-2121, Vol. 4, no special issue: REV2008, p. 63-68Article in journal (Refereed)
    Abstract [en]

    For experiments to be reproducible, it is important to have a known and controlled environment. This requires isolation from the surroundings. For security experiments, e.g. with hostile software, this is even more important as the experiment can affect the environment in adverse ways. In a normal campus laboratory, isolation can be achieved by network separation. For an online environment, where remote control is essential, separation and isolation are still needed, and therefore the security implications must be considered. In this paper, a way to enable remote experiments is described, where users are given full control over the computer installation. By automating the install procedure and dynamically creating isolated experiment networks, remote users are provided with the tools needed to do experiments in a reproducible and secure environment.

  • 4795.
    Zafar, Atique
    et al.
    Blekinge Institute of Technology, School of Computing.
    Ali, Sajad
    Blekinge Institute of Technology, School of Computing.
    Investigation of Failure and Success Factors of Integration Process in Global Software Development: Literature Review and Delphi Survey2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Software development work undertaken by virtual teams dispersed across time, space, and organizational boundaries is referred as Global Software Development (GSD) with emphasis on “globalization”. In GSD, teams within same organization (off-shore) or different organizations (outsource) from multiple geographic locations are involved. GSD is becoming a norm and more software projects are undertaken in GSD setting due to the benefits associated with it. However, there remain many challenges that can adversely affect the ability to realize those benefits. One of the challenges is to overcome the problems faced during integration of the functional components developed by different teams at different geographic locations. Incompatibilities and hidden issues surface during functional components integration which is very costly to fix at this stage and can lead to delay, lower product quality or even failure of a GSD project. In this regard, this study investigates integration problems that occurred due to different reasons during different phases/stages of GSD, along with successful integration practices with their relative importance. The study produces lists of failure and success factors, and then further prioritized that failure and success factors lists through Delphi experts. Failure and success factors present an extensive knowledge of integration problems and practical solutions. In addition, their relative importance highlights the severity and importance of each failure and success factor. The results of this study not only help to understand integration issues and solution, but provide a platform to develop a solid strategy at early stage of GSD.

  • 4796.
    Zahda, Showayb
    Blekinge Institute of Technology, School of Computing.
    Obsolete Software Requirements2011Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Context. Requirements changes are unavoidable in any software project. Requirements change over time as software projects progress, and involved stakeholders (mainly customers) and developers gain better understanding of the final product. Additionally, time and budget constraints prevent implementing all candidate requirements and force project management to select a subset of requirements that are prioritized more important than the others so as to be implemented. As a result, some requirements become cancelled and deleted during the elicitation and specification phase while other requirements are considered not important during the prioritization phase. A common scenario in this situation is to leave the excluded requirements for being considered in the next release. The constant leaving of the excluded requirements for the next release may simply render them obsolete.

  • 4797.
    Zalasinski, Marcin
    et al.
    Czestochowa University of Technology, POL.
    Cpalka, Krzysztof
    Czestochowa University of Technology, POL.
    Rakus-Andersson, Elisabeth
    Blekinge Institute of Technology, Faculty of Engineering, Department of Mathematics and Natural Sciences.
    An Idea of the Dynamic Signature Verification Based on a Hybrid Approach2016In: Artificial Intelligence and Soft Computing LNAI 9693: Proceedings of the 15th International Conference, ICAISC 2016 / [ed] Leszek Rutkowski et al., Berlin Heidelberg: Springer, 2016, Vol. II, p. 232-246Conference paper (Refereed)
    Abstract [en]

    Dynamic signature verification is a very interesting biometric issue. It is difficult to realize because signatures of the user are characterized by relatively high intra-class and low inter-class variability. However, this method of an identity verification is commonly socially acceptable.

    It is a big advantage of the dynamic signature biometric attribute. In this paper, we propose a new hybrid algorithm for the dynamic signature verification based on global and regional approach. We present the simulation results of the proposed method for BioSecure DS2 database, distributed by the BioSecure Association.

  • 4798.
    Zavareh, Alireza
    Blekinge Institute of Technology, School of Engineering.
    Analytical and Numerical methods for a Mean curvature flow equation with applications to financial Mathematics and image processing2012Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    This thesis provides an analytical and two numerical methods for solving a parabolic equation of two-dimensional mean curvature flow with some applications. In analytical method, this equation is solved by Lie group analysis method, and in numerical method, two algorithms are implemented in MATLAB for solving this equation. A geometric algorithm and a step-wise algorithm; both are based on a deterministic game theoretic representation for parabolic partial differential equations, originally proposed in the genial work of Kohn-Serfaty [1].

  • 4799.
    Zeb, Falak
    et al.
    Blekinge Institute of Technology, School of Computing.
    Naseem, Sajid
    Blekinge Institute of Technology, School of Computing.
    Guidelines for the Deployment of Biometrics Technology in Blekinge Health Care System with the Focus on Human Perceptions and Cost Factor2010Independent thesis Advanced level (degree of Master (Two Years))Student thesis
    Abstract [en]

    Biometrics Technology is an authentication technology that identifies the individuals from their physical and behavioral characteristics. Despite the fact that biometrics technology provides robust authentication and enhanced security, it has not yet been implemented in many parts of the world due to certain issues i.e. human perceptions of the biometrics technology and cost factor, involved in the deployment of biometrics technology. As the biometrics technology involves identity management of individuals that’s why the humans perceptions of biometrics technology i.e. privacy concerns, security concerns and user acceptance issue play a very important role in the deployment of biometrics technology. There for the human perceptions and cost factor need to be considered before any deployment of biometrics technology. The aim of this thesis work is to study and analyze how the people’s perceptions and cost factor can be solved for the deployment of biometrics technology in Blekinge health care system. Literature study, interviews and survey are performed by authors for the identification and understanding of the human perceptions and cost factor. Based on these, solutions in form of guidelines to the issues involved in the biometrics technology deployment in Blekinge health care system Sweden are given.

  • 4800.
    Zeeshan, Ahmed
    Blekinge Institute of Technology, School of Engineering, Department of Interaction and System Design.
    Integration of Variants Handling in M-System-NT2006Independent thesis Advanced level (degree of Master (One Year))Student thesis
    Abstract [en]

    This Master thesis proposes a solution to manage variabilities of software product line applications. The objective of the research is to support software decision makers in handling additional software complexity introduced by product line architectures. In order to fulfill this objective an approach to analyze, visualize, and measure product line specific characteristics of the C/C++ source code are proposed. The approach is validated in an empirical experiment using an open source software system. For that purpose the approach is first implemented into ®1 M-System-NT, an existing software measurement tool developed at Fraunhofer. The target hypothesis of the Institute for Experimental Software engineering research master thesis to perform static analysis of C/C++ source code, measure traditional and product line measures to identify the correlation between measures and indicate the fault proneness.

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