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  • 1.
    ABBAS, FAHEEM
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Intelligent Container Stacking System at Seaport Container Terminal2016Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Context: The workload at seaport container terminal is increasing gradually. We need to improve the performance of terminal to fulfill the demand. The key section of the container terminal is container stacking yard which is an integral part of the seaside and the landside. So its performance has the effects on both sides. The main problem in this area is unproductive moves of containers. However, we need a well-planned stacking area in order to increase the performance of terminal and maximum utilization of existing resources.

    Objectives: In this work, we have analyzed the existing container stacking system at Helsingborg seaport container terminal, Sweden, investigated the already provided solutions of the problem and find the best optimization technique to get the best possible solution. After this, suggest the solution, test the proposed solution and analyzed the simulation based results with respect to the desired solution.

    Methods: To identify the problem, methods and proposed solutions of the given problem in the domain of container stacking yard management, a literature review has been conducted by using some e-resources/databases. A GA with best parametric values is used to get the best optimize solution. A discrete event simulation model for container stacking in the yard has been build and integrated with genetic algorithm. A proposed mathematical model to show the dependency of cost minimization on the number of containers’ moves.

    Results: The GA has been achieved the high fitness value versus generations for 150 containers to storage at best location in a block with 3 tier levels and to minimize the unproductive moves in the yard. A comparison between Genetic Algorithm and Tabu Search has been made to verify that the GA has performed better than other algorithm or not. A simulation model with GA has been used to get the simulation based results and to show the container handling by using resources like AGVs, yard crane and delivery trucks and container stacking and retrieval system in the yard. The container stacking cost is directly proportional to the number of moves has been shown by the mathematical model.

    Conclusions: We have identified the key factor (unproductive moves) that is the base of other key factors (time & cost) and has an effect on the performance of the stacking yard and overall the whole seaport terminal. We have focused on this drawback of stacking system and proposed a solution that makes this system more efficient. Through this, we can save time and cost both. A Genetic Algorithm is a best approach to solve the unproductive moves problem in container stacking system.

  • 2.
    Abbireddy, Sharath
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    A Model for Capacity Planning in Cassandra: Case Study on Ericsson’s Voucher System2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Cassandra is a NoSQL(Not only Structured Query Language) database which serves large amount of data with high availability .Cassandra data storage dimensioning also known as Cassandra capacity planning refers to predicting the amount of disk storage required when a particular product is deployed using Cassandra. This is an important phase in any product development lifecycle involving Cassandra data storage system. The capacity planning is based on many factors which are classified as Cassandra specific and Product specific.This study is to identify the different Cassandra specific and product specific factors affecting the disk space in Cassandra data storage system. Based on these factors a model is to be built which would predict the disk storage for Ericsson’s voucher system.A case-study is conducted on Ericsson’s voucher system and its Cassandra cluster. Interviews were conducted on different Cassandra users within Ericsson R&D to know their opinion on capacity planning approaches and factors affecting disk space for Cassandra. Responses from the interviews were transcribed and analyzed using grounded theory.A total of 9 Cassandra specific factors and 3 product specific factors are identified and documented. Using these 12 factors a model was built. This model was used in predicting the disk space required for voucher system’s Cassandra.The factors affecting disk space for deploying Cassandra are now exhaustively identified. This makes the capacity planning process more efficient. Using these factors the Voucher system’s disk space for deployment is predicted successfully.

  • 3.
    Abdelraheem, Mohamed Ahmed
    et al.
    SICS Swedish ICT AB, SWE.
    Gehrmann, Christian
    SICS Swedish ICT AB, SWE.
    Lindström, Malin
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Nordahl, Christian
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Executing Boolean queries on an encrypted Bitmap index2016Ingår i: CCSW 2016 - Proceedings of the 2016 ACM Cloud Computing Security Workshop, co-located with CCS 2016, Association for Computing Machinery (ACM), 2016, s. 11-22Konferensbidrag (Refereegranskat)
    Abstract [en]

    We propose a simple and efficient searchable symmetric encryption scheme based on a Bitmap index that evaluates Boolean queries. Our scheme provides a practical solution in settings where communications and computations are very constrained as it offers a suitable trade-off between privacy and performance.

  • 4.
    Abdelrasoul, Nader
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Optimization Techniques For an Artificial Potential Fields Racing Car Controller2013Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    Context. Building autonomous racing car controllers is a growing field of computer science which has been receiving great attention lately. An approach named Artificial Potential Fields (APF) is used widely as a path finding and obstacle avoidance approach in robotics and vehicle motion controlling systems. The use of APF results in a collision free path, it can also be used to achieve other goals such as overtaking and maneuverability. Objectives. The aim of this thesis is to build an autonomous racing car controller that can achieve good performance in terms of speed, time, and damage level. To fulfill our aim we need to achieve optimality in the controller choices because racing requires the highest possible performance. Also, we need to build the controller using algorithms that does not result in high computational overhead. Methods. We used Particle Swarm Optimization (PSO) in combination with APF to achieve optimal car controlling. The Open Racing Car Simulator (TORCS) was used as a testbed for the proposed controller, we have conducted two experiments with different configuration each time to test the performance of our APF- PSO controller. Results. The obtained results showed that using the APF-PSO controller resulted in good performance compared to top performing controllers. Also, the results showed that the use of PSO proved to enhance the performance compared to using APF only. High performance has been proven in the solo driving and in racing competitions, with the exception of an increased level of damage, however, the level of damage was not very high and did not result in a controller shut down. Conclusions. Based on the obtained results we have concluded that the use of PSO with APF results in high performance while taking low computational cost.

  • 5.
    Abghari, Shahrooz
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Data Modeling for Outlier Detection2018Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This thesis explores the data modeling for outlier detection techniques in three different application domains: maritime surveillance, district heating, and online media and sequence datasets. The proposed models are evaluated and validated under different experimental scenarios, taking into account specific characteristics and setups of the different domains.

    Outlier detection has been studied and applied in many domains. Outliers arise due to different reasons such as fraudulent activities, structural defects, health problems, and mechanical issues. The detection of outliers is a challenging task that can reveal system faults, fraud, and save people's lives. Outlier detection techniques are often domain-specific. The main challenge in outlier detection relates to modeling the normal behavior in order to identify abnormalities. The choice of model is important, i.e., an incorrect choice of data model can lead to poor results. This requires a good understanding and interpretation of the data, the constraints, and the requirements of the problem domain. Outlier detection is largely an unsupervised problem due to unavailability of labeled data and the fact that labeled data is expensive.

    We have studied and applied a combination of both machine learning and data mining techniques to build data-driven and domain-oriented outlier detection models. We have shown the importance of data preprocessing as well as feature selection in building suitable methods for data modeling. We have taken advantage of both supervised and unsupervised techniques to create hybrid methods. For example, we have proposed a rule-based outlier detection system based on open data for the maritime surveillance domain. Furthermore, we have combined cluster analysis and regression to identify manual changes in the heating systems at the building level. Sequential pattern mining for identifying contextual and collective outliers in online media data have also been exploited. In addition, we have proposed a minimum spanning tree clustering technique for detection of groups of outliers in online media and sequence data. The proposed models have been shown to be capable of explaining the underlying properties of the detected outliers. This can facilitate domain experts in narrowing down the scope of analysis and understanding the reasons of such anomalous behaviors. We have also investigated the reproducibility of the proposed models in similar application domains.

  • 6.
    Abghari, Shahrooz
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Boeva, Veselka
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Lavesson, Niklas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Gustafsson, Jörgen
    Ericsson AB.
    Shaikh, Junaid
    Ericsson AB.
    Outlier Detection for Video Session Data Using Sequential Pattern Mining2018Ingår i: ACM SIGKDD Workshop On Outlier Detection De-constructed, 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    The growth of Internet video and over-the-top transmission techniqueshas enabled online video service providers to deliver highquality video content to viewers. To maintain and improve thequality of experience, video providers need to detect unexpectedissues that can highly affect the viewers’ experience. This requiresanalyzing massive amounts of video session data in order to findunexpected sequences of events. In this paper we combine sequentialpattern mining and clustering to discover such event sequences.The proposed approach applies sequential pattern mining to findfrequent patterns by considering contextual and collective outliers.In order to distinguish between the normal and abnormal behaviorof the system, we initially identify the most frequent patterns. Thena clustering algorithm is applied on the most frequent patterns.The generated clustering model together with Silhouette Index areused for further analysis of less frequent patterns and detectionof potential outliers. Our results show that the proposed approachcan detect outliers at the system level.

  • 7.
    Abghari, Shahrooz
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Boeva, Veselka
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Lavesson, Niklas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Ickin, Selim
    Ericsson, SWE.
    Gustafsson, Jörgen
    Ericsson, SWE.
    A Minimum Spanning Tree Clustering Approach for Outlier Detection in Event Sequences2018Ingår i: 2018 17TH IEEE INTERNATIONAL CONFERENCE ON MACHINE LEARNING AND APPLICATIONS (ICMLA) / [ed] Wani M.A.,Sayed-Mouchaweh M.,Lughofer E.,Gama J.,Kantardzic M., IEEE, 2018, s. 1123-1130, artikel-id 8614207Konferensbidrag (Refereegranskat)
    Abstract [en]

    Outlier detection has been studied in many domains. Outliers arise due to different reasons such as mechanical issues, fraudulent behavior, and human error. In this paper, we propose an unsupervised approach for outlier detection in a sequence dataset. The proposed approach combines sequential pattern mining, cluster analysis, and a minimum spanning tree algorithm in order to identify clusters of outliers. Initially, the sequential pattern mining is used to extract frequent sequential patterns. Next, the extracted patterns are clustered into groups of similar patterns. Finally, the minimum spanning tree algorithm is used to find groups of outliers. The proposed approach has been evaluated on two different real datasets, i.e., smart meter data and video session data. The obtained results have shown that our approach can be applied to narrow down the space of events to a set of potential outliers and facilitate domain experts in further analysis and identification of system level issues.

  • 8.
    Abghari, Shahrooz
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    García Martín, Eva
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Johansson, Christian
    NODA Intelligent Systems AB, SWE.
    Lavesson, Niklas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Grahn, Håkan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Trend analysis to automatically identify heat program changes2017Ingår i: Energy Procedia, Elsevier, 2017, Vol. 116, s. 407-415Konferensbidrag (Refereegranskat)
    Abstract [en]

    The aim of this study is to improve the monitoring and controlling of heating systems located at customer buildings through the use of a decision support system. To achieve this, the proposed system applies a two-step classifier to detect manual changes of the temperature of the heating system. We apply data from the Swedish company NODA, active in energy optimization and services for energy efficiency, to train and test the suggested system. The decision support system is evaluated through an experiment and the results are validated by experts at NODA. The results show that the decision support system can detect changes within three days after their occurrence and only by considering daily average measurements.

  • 9.
    Abheeshta, Putta
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Comparative Analysis of Software Development Practices across Software Organisations: India and Sweden2016Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Context. System Development Methodologies (SDM’s) have been an area of intensive research in the field of software engineering. Different software organisations adopt different development methodologies and use different development practices. The frequency of usage of development practices and acceptance factors for adoption of development methodology are crucial for software organisations. The factors of acceptance and development practices differ across geographical locations. Many challenges have been presented in the literature with respect to the mismatch of the development practices across organisations while collaborating across organisations in distributed development. There is no considerable amount of research done in context of differences across development practices and acceptance factors for adoption of a particular development methodology. Objectives. The primary objectives of the research are to find out a) differences in (i) practice usage (ii) acceptance factors such as organisational, social and cultural b) explore the reasons for the differences and also investigate consequences of such differences while collaborating, across organisations located in India and Sweden. Methods. A literature review was conducted by searching in scientific databases for identifying common agile and plan-driven development practices and acceptance theories for development methodologies. Survey was conducted across organisations located in India and Sweden to find out the usage frequency of development practices and acceptance factors. Ten interviews were conducted to investigate, reasons for differences and consequences of differences from the software practitioners from organisations located in India and Sweden. Literature evidences were used to support the results collected from interviews. Results. From the survey, organisations in India have adopted a higher frequency of plan driven practices when compared to Sweden and agile practices were adopted at higher frequency in Sweden when compared to India. The number of organisations adopting "pure agile" methodologies have been significantly higher in Sweden. There was significant differences were found across the acceptance factors such as cultural, organisational, image and career factors between India and Sweden. The factors such as cultural, social, human, business and organisational factors are responsible for such differences across development practices and acceptance factors. Challenges related to communication, coordination and control were found due to the differences, while collaborating between Indian and Sweden sites. Conclusions. The study signifies the importance of identifying the frequency of development practices and also the acceptance factors responsible for adoption of development methodologies in the software organisations. The mismatch between these practices will led to various challenges. The study draws insights into various non-technical factors such as cultural, human, organisational, business and social while collaborating between organisations. Variations across these factors will lead to many coordination, communication and control issues. Keywords: Development Practices, Agile Development, Plan Driven Development, Acceptance Factors, Global Software Development.

  • 10.
    Acevedo, Carlos
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för teknik och estetik.
    Developing Inclusive Innovation Processes and Co-Evolutionary University-Society Approaches in Bolivia2018Doktorsavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    This study is part of a worldwide debate on inclusive innovation systems in developing

    countries and particularly on the co-evolutionary processes taking place, seen from the

    perspective of a public university. The increasing literature that discusses how innovation

    systems and development can foster more inclusive and sustainable societies has

    inspired this thesis work. Thus, the main problem handled in the research concerns the

    question how socially sensitive research practices and policies at a public university in

    Bolivia can be stimulated within emerging innovation system dynamics. In that vein,

    empirical knowledge is developed at the Universidad Mayor de San SimoÅLn (UMSS),

    Cochabamba as a contribution to experience-based learning in the field. Analysis are

    nourished by a dialogue with the work of prominent Latin American scholars and

    practitioners around the idea of a developmental university and the democratization

    of knowledge. The reader will be able to recognize a recursive transit between theory

    and practice, where a number of relevant concepts are contextualized and connected

    in order to enable keys of critical interpretation and paths of practices amplification

    for social inclusion purposes established. The study shows how, based on a previous

    experience, new competences and capacities for the Technology Transfer Unit (UTT)

    at UMSS were produced, in this case transforming itself into a University Innovation

    Centre. Main lessons gained in that experience came from two pilot cluster development

    (food and leather sectors) and a multidisciplinary researchers network (UMSS

    Innovation Team) where insights found can improve future collaborative relations between

    university and society for inclusive innovation processes within the Bolivian

    context.

  • 11.
    Adamov, Alexander
    et al.
    Kharkiv Natl Univ Radio Elect, NioGuard Secur Lab, Kharkov, Kharkiv Oblast, Ukraine..
    Carlsson, Anders
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    A Sandboxing Method to Protect Cloud Cyberspace2015Ingår i: PROCEEDINGS OF 2015 IEEE EAST-WEST DESIGN & TEST SYMPOSIUM (EWDTS), IEEE Communications Society, 2015Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper addresses the problem of protecting cloud environments against targeted attacks, which have become a popular mean of gaining access to organization's confidential information and resources of cloud providers. Only in 2015 eleven targeted attacks have been discovered by Kaspersky Lab. One of them - Duqu2 - successfully attacked the Lab itself. In this context, security researchers show rising concern about protecting corporate networks and cloud infrastructure used by large organizations against such type of attacks. This article describes a possibility to apply a sandboxing method within a cloud environment to enforce security perimeter of the cloud.

  • 12.
    Adamov, Alexander
    et al.
    Harkivskij Nacionalnij Universitet Radioelectroniki, UKR.
    Carlsson, Anders
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Cloud incident response model2016Ingår i: Proceedings of 2016 IEEE East-West Design and Test Symposium, EWDTS 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper addresses the problem of incident response in clouds. A conventional incident response model is formulated to be used as a basement for the cloud incident response model. Minimization of incident handling time is considered as a key criterion of the proposed cloud incident response model that can be done at the expense of embedding infrastructure redundancy into the cloud infrastructure represented by Network and Security Controllers and introducing Security Domain for threat analysis and cloud forensics. These architectural changes are discussed and applied within the cloud incident response model. © 2016 IEEE.

  • 13.
    Adamov, Alexander
    et al.
    Kharkiv National University of Radioelectronics, UKR.
    Carlsson, Anders
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    The state of ransomware: Trends and mitigation techniques2017Ingår i: Proceedings of 2017 IEEE East-West Design and Test Symposium, EWDTS 2017, Institute of Electrical and Electronics Engineers Inc. , 2017, artikel-id 8110056Konferensbidrag (Refereegranskat)
    Abstract [en]

    This paper contains an analysis of the payload of the popular ransomware for Windows, Android, Linux, and MacOSX platforms. Namely, VaultCrypt (CrypVault), TeslaCrypt, NanoLocker, Trojan-Ransom.Linux.Cryptor, Android Simplelocker, OSX/KeRanger-A, WannaCry, Petya, NotPetya, Cerber, Spora, Serpent ransomware were put under the microscope. A set of characteristics was proposed to be used for the analysis. The purpose of the analysis is generalization of the collected data that describes behavior and design trends of modern ransomware. The objective is to suggest ransomware threat mitigation techniques based on the obtained information. The novelty of the paper is the analysis methodology based on the chosen set of 13 key characteristics that helps to determine similarities and differences thorough the list of ransomware put under analysis. Most of the ransomware samples presented were manually analyzed by the authors eliminating contradictions in descriptions of ransomware behavior published by different malware research laboratories through verification of the payload of the latest versions of ransomware. © 2017 IEEE.

  • 14.
    Adapa, Sasank Sai Sujan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    APPLYING LEAN PRINCIPLES FOR PERFORMANCE ORIENTED SERVICE DESIGN OF VIRTUAL NETWORK FUNCTIONS FOR NFV INFRASTRUCTURE: Concepts of Lean2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Context. Network Function Virtualization was recently proposed by European Telecommunications Standards Institute (ETSI) to improve the network service flexibility by virtualization of network services and applications that run on hardware. To virtualize network functions, the software is decoupled from underlying physical hardware. NFV aims to transform industries by reducing capital investments on hardware by using commercial-of-the-shelf (COTS) hardware. NFV makes rapid innovative growth in telecom services through software based service deployment.

    Objectives. This thesis work aims to investigate how business organizations function and the roles in defining a service relationship model. The work also aims to define a service relationship model and to validate it via proof of concept using network function virtualization as a service. For this thesis, we finally apply lean principles for the defined service relationship model to reduce waste and investigate how lean benefits the model to be proven as performance service oriented.

    Methods. The essence of this work is to make a business organization lean by investigating its actions and applying lean principles. To elaborate, this thesis work involves in a research of papers from IEEE, TMF, IETF and Ericsson. It results in modelling of a PoC by following requirement analysis methodology and by applying lean principles to eliminate unnecessary processes which doesn’t add any value.

    Results. The results of the work include a full-fledged service relationship model that include three service levels with roles that can fit in to requirement specifications of NFV infrastructure. The results also show the service levels functionalities and their relationships between the roles. It has also been observed that the services that are needed to be standardized are defined with syntax for ways to describe network functions. It is observed that lean principles benefit the service relationship model from reducing waste factors and hereby providing a PoC which is performance service oriented.

    Conclusions. We conclude that roles defined are fit for the service relationship model designed. Moreover, we conclude that the model can hence contain the flow of service by standardizing the subservices and reducing waste interpreted with lean principles and there is a need for further use case proof of the model in full scale industry trials. It also concludes the ways to describe network functions syntax which follows lean principles that are essential to have them for the sub-services standardization. However, PoC defined can be an assurance to the NFV infrastructure.

  • 15.
    Addu, Raj Kiran
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Potuvardanam, Vinod Kumar
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Effect of Codec Performance on Video QoE for videos encoded with Xvid, H.264 and WebM/VP82014Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

    In recent years, there has been a significant growth in multimedia services such as mobile video streaming, Video-on-Demand and video conferencing. This has led to the development of various video coding techniques, aiming to deliver high quality video while using available bandwidth efficiently. This upsurge in the usage of video applications has also resulted in making endusers more quality-conscious. In order to meet the users’ expectations, the Quality of Experience (QoE) studies has gained utmost importance from both researchers and service providers. This thesis aims to compare the performance of H.264/AVC, Xvid and WebM/VP8 video codecs in wired and wireless networks. The codec performance is evaluated for different packet loss and delay variation values. The evaluation of codec performance is done using both subjective and objective assessment methods. In subjective assessment method, the evaluation of video codec performance is done using ITU-T recommended Absolute Category Rating (ACR) method. Using this method the perceptual video quality ratings are taken from the users, which are then averaged to obtain Mean Opinion Score. These obtained scores are used to analyze the performance of encoded videos with respect to users’ perception. In addition to subjective assessment method, the quality of encoded video is also measured using objective assessment method. The objective metric SSIM (Structural Similarity) is used to evaluate the performance of encoded videos. Based on the results, it was found that for lower packet loss and delay variation values H.264 showed better results when compared to Xvid and WebM/VP8 whereas, WebM/VP8 outperformed Xvid and H.264 for higher packet loss and delay variation values. On the whole, H.264 and WebM/VP8 performed better than Xvid. It was also found that all three video codecs performed better in wired network when compared to the wireless network.

  • 16.
    Adidamu, Naga Shruti
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Bheemisetty, Shanmukha Sai
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Assessment of Ixia BreakingPoint Virtual Edition: Evolved Packet Gateway2018Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 17.
    Advaita, Advaita
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Gali, Mani Meghala
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Chu, Thi My Chinh
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Zepernick, Hans-Juergen
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier. Blekinge Inst Technol, SE-37179 Karlskrona, Sweden..
    Outage Probability of MIMO Cognitive Cooperative Radio Networks with Multiple AF Relays Using Orthogonal Space-Time Block Codes2017Ingår i: 2017 IEEE 13TH INTERNATIONAL CONFERENCE ON WIRELESS AND MOBILE COMPUTING, NETWORKING AND COMMUNICATIONS (WIMOB), IEEE , 2017, s. 84-89Konferensbidrag (Refereegranskat)
    Abstract [en]

    In this paper, we analyze the outage probability of multiple-input multiple-output cognitive cooperative radio networks (CCRNs) with multiple opportunistic amplify-and-forward relays. The CCRN applies underlay spectrum access accounting for the interference power constraint of a primary network and utilizes orthogonal space-time block coding to transmit multiple data streams across a number of antennas over several time slots. As such, the system exploits both time and space diversity to improve the transmission reliability over Nakagami.. fading. The CCRN applies opportunistic relaying in which the relay offering the highest signal-to-noise ratio at the receiver is selected to forward the transmit signal. Furthermore, selection combining is adopted at the secondary receiver to process the signal from the direct and relaying transmissions. To evaluate system performance, we derive an expression for the outage probability which is valid for an arbitrary number of antennas at the source, relays, and receiver of the CCRN. Selected numerical results are provided using Mathematica for analysis and Matlab for simulations, to reveal the effect of network parameters on the outage probability of the system.

  • 18. Afzal, Wasif
    et al.
    Ghazi, Ahmad Nauman
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Itkonen, Juha
    Torkar, Richard
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Andrews, Anneliese
    Bhatti, Khurram
    An experiment on the effectiveness and efficiency of exploratory testing2015Ingår i: Empirical Software Engineering, ISSN 1382-3256, Vol. 20, nr 3, s. 844-878Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The exploratory testing (ET) approach is commonly applied in industry, but lacks scientific research. The scientific community needs quantitative results on the performance of ET taken from realistic experimental settings. The objective of this paper is to quantify the effectiveness and efficiency of ET vs. testing with documented test cases (test case based testing, TCT). We performed four controlled experiments where a total of 24 practitioners and 46 students performed manual functional testing using ET and TCT. We measured the number of identified defects in the 90-minute testing sessions, the detection difficulty, severity and types of the detected defects, and the number of false defect reports. The results show that ET found a significantly greater number of defects. ET also found significantly more defects of varying levels of difficulty, types and severity levels. However, the two testing approaches did not differ significantly in terms of the number of false defect reports submitted. We conclude that ET was more efficient than TCT in our experiment. ET was also more effective than TCT when detection difficulty, type of defects and severity levels are considered. The two approaches are comparable when it comes to the number of false defect reports submitted.

  • 19. Afzal, Wasif
    et al.
    Torkar, Richard
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Towards benchmarking feature subset selection methods for software fault prediction2016Ingår i: Studies in Computational Intelligence, Springer, 2016, 617, Vol. 617, s. 33-58Kapitel i bok, del av antologi (Refereegranskat)
    Abstract [en]

    Despite the general acceptance that software engineering datasets often contain noisy, irrelevant or redundant variables, very few benchmark studies of feature subset selection (FSS) methods on real-life data from software projects have been conducted. This paper provides an empirical comparison of state-of-the-art FSS methods: information gain attribute ranking (IG); Relief (RLF); principal component analysis (PCA); correlation-based feature selection (CFS); consistencybased subset evaluation (CNS); wrapper subset evaluation (WRP); and an evolutionary computation method, genetic programming (GP), on five fault prediction datasets from the PROMISE data repository. For all the datasets, the area under the receiver operating characteristic curve—the AUC value averaged over 10-fold cross-validation runs—was calculated for each FSS method-dataset combination before and after FSS. Two diverse learning algorithms, C4.5 and naïve Bayes (NB) are used to test the attribute sets given by each FSS method. The results show that although there are no statistically significant differences between the AUC values for the different FSS methods for both C4.5 and NB, a smaller set of FSS methods (IG, RLF, GP) consistently select fewer attributes without degrading classification accuracy. We conclude that in general, FSS is beneficial as it helps improve classification accuracy of NB and C4.5. There is no single best FSS method for all datasets but IG, RLF and GP consistently select fewer attributes without degrading classification accuracy within statistically significant boundaries. © Springer International Publishing Switzerland 2016.

  • 20.
    Ahlgren, Filip
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datavetenskap.
    Local And Network Ransomware Detection Comparison2019Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Background. Ransomware is a malicious application encrypting important files on a victim's computer. The ransomware will ask the victim for a ransom to be paid through cryptocurrency. After the system is encrypted there is virtually no way to decrypt the files other than using the encryption key that is bought from the attacker.

    Objectives. In this practical experiment, we will examine how machine learning can be used to detect ransomware on a local and network level. The results will be compared to see which one has a better performance.

    Methods. Data is collected through malware and goodware databases and then analyzed in a virtual environment to extract system information and network logs. Different machine learning classifiers will be built from the extracted features in order to detect the ransomware. The classifiers will go through a performance evaluation and be compared with each other to find which one has the best performance.

    Results. According to the tests, local detection was both more accurate and stable than network detection. The local classifiers had an average accuracy of 96% while the best network classifier had an average accuracy of 89.6%.

    Conclusions. In this case the results show that local detection has better performance than network detection. However, this can be because the network features were not specific enough for a network classifier. The network performance could have been better if the ransomware samples consisted of fewer families so better features could have been selected.

  • 21.
    Ahlqvist, Robin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för teknik och estetik.
    Raymond, Djerf
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för teknik och estetik.
    En posthumanistisk animerad framtid2018Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Detta kandidatarbete undersöker hur man med animering och ljuddesign i en designprocess kan illustrera en jämställd och ansvarsfull teknologisk framtid utifrån posthumanistiska teorier och filosofier. Under arbetets gång har vi undersökt animationsmetoder, deltagande design, ljuddesign och teknik samt den teknologiska utvecklingen. I detta kandidatarbetet presenterar vi processen och de metoder vi använt oss av för att skapa vår gestaltning som är en animerad kortfilm.

  • 22.
    Ahlström, Eric
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Holmqvist, Lucas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Goswami, Prashant
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    Comparing Traditional Key Frame and Hybrid Animation2017Ingår i: SCA '17 Proceedings of the ACM SIGGRAPH / Eurographics Symposium on Computer Animation, ACM Digital Library, 2017, artikel-id nr. a20Konferensbidrag (Refereegranskat)
    Abstract [en]

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

  • 23.
    Ahmadi Mehri, Vida
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    An Investigation of CPU utilization relationship between host and guests in a Cloud infrastructure2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Cloud computing stands as a revolution in IT world in recent years. This technology facilitates resource sharing by reducing hardware costs for business users and promises energy efficiency and better resource utilization to the service providers. CPU utilization is a key metric considered in resource management across clouds.

    The main goal of this thesis study is directed towards investigating CPU utilization behavior with regard to host and guest, which would help us in understanding the relationship between them. It is expected that perception of these relationships would be helpful in resource management.

    Working towards our goal, the methodology we adopted is experi- mental research. This involves experimental modeling, measurements and observations from the results. The experimental setup covers sev- eral complex scenarios including cloud and a standalone virtualization system. The results are further analyzed for a visual correlation.

    Results show that CPU utilization in cloud and virtualization sce- nario coincides. More experimental scenarios are designed based on the first observations. The obtaining results show the irregular behav- ior between PM and VM in variable workload.

    CPU utilization retrieved from both cloud and a standalone system is similar. 100% workload situations showed that CPU utilization is constant with no correlation co-efficient obtained. Lower workloads showed (more/less) correlation in most of the cases in our correlation analysis. It is expected that more number of iterations can possibly vary the output. Further analysis of these relationships for proper resource management techniques will be considered. 

  • 24.
    Ahmadi Mehri, Vida
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datavetenskap.
    Towards Secure Collaborative AI Service Chains2019Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    Abstract [en]

    At present, Artificial Intelligence (AI) systems have been adopted in many different domains such as healthcare, robotics, automotive, telecommunication systems, security, and finance for integrating intelligence in their services and applications. The intelligent personal assistant such as Siri and Alexa are examples of AI systems making an impact on our daily lives. Since many AI systems are data-driven systems, they require large volumes of data for training and validation, advanced algorithms, computing power and storage in their development process. Collaboration in the AI development process (AI engineering process) will reduce cost and time for the AI applications in the market. However, collaboration introduces the concern of privacy and piracy of intellectual properties, which can be caused by the actors who collaborate in the engineering process.  This work investigates the non-functional requirements, such as privacy and security, for enabling collaboration in AI service chains. It proposes an architectural design approach for collaborative AI engineering and explores the concept of the pipeline (service chain) for chaining AI functions. In order to enable controlled collaboration between AI artefacts in a pipeline, this work makes use of virtualisation technology to define and implement Virtual Premises (VPs), which act as protection wrappers for AI pipelines. A VP is a virtual policy enforcement point for a pipeline and requires access permission and authenticity for each element in a pipeline before the pipeline can be used.  Furthermore, the proposed architecture is evaluated in use-case approach that enables quick detection of design flaw during the initial stage of implementation. To evaluate the security level and compliance with security requirements, threat modeling was used to identify potential threats and vulnerabilities of the system and analyses their possible effects. The output of threat modeling was used to define countermeasure to threats related to unauthorised access and execution of AI artefacts.

  • 25.
    Ahmadi Mehri, Vida
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik. Blekinge Institute of technology.
    Ilie, Dragos
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Tutschku, Kurt
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Privacy and DRM Requirements for Collaborative Development of AI Application2018Ingår i: ACM International Conference Proceeding Series, 2018, artikel-id 3233268Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of data is essential for the capabilities of Data-driven Artificial intelligence (AI), Deep Learning and Big Data analysis techniques. This data usage, however, raises intrinsically the concerns on data privacy. In addition, supporting collaborative development of AI applications across organisations has become a major need in AI system design. Digital Rights Management (DRM) is required to protect intellectual property in such collaboration. As a consequence of DRM, privacy threats and privacy-enforcing mechanisms will interact with each other.

    This paper describes the privacy and DRM requirements in collaborative AI system design using AI pipelines. It describes the relationships between DRM and privacy and outlines the threats against these non-functional features. Finally, the paper provides first security architecture to protect against the threats on DRM and privacy in collaborative AI design using AI pipelines. 

  • 26.
    Ahmadi Mehri, Vida
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Ilie, Dragos
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Tutschku, Kurt
    Towards Privacy Requirements for Collaborative Development of AI Applications2018Ingår i: 14th Swedish National Computer Networking Workshop (SNCNW), 2018Konferensbidrag (Refereegranskat)
    Abstract [en]

    The use of data is essential for the capabilities of Data- driven Artificial intelligence (AI), Deep Learning and Big Data analysis techniques. The use of data, however, raises intrinsically the concern of the data privacy, in particular for the individuals that provide data. Hence, data privacy is considered as one of the main non-functional features of the Next Generation Internet. This paper describes the privacy challenges and requirements for collaborative AI application development. We investigate the constraints of using digital right management for supporting collaboration to address the privacy requirements in the regulation.

  • 27.
    Ahmed, Qutub Uddin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Mujib, Saifullah Bin
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Context Aware Reminder System: Activity Recognition Using Smartphone Accelerometer and Gyroscope Sensors Supporting Context-Based Reminder Systems2014Självständigt arbete på avancerad nivå (masterexamen)Studentuppsats (Examensarbete)
    Abstract [en]

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

  • 28.
    Ahrneteg, Jakob
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Kulenovic, Dean
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Semantic Segmentation of Historical Document Images Using Recurrent Neural Networks2019Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Bakgrund. Detta arbete handlar om semantisk segmentering av historiska dokument med recurrent neural network. Semantisk segmentering av dokument inbegriper att dela in ett dokument i olika regioner, något som är viktigt för att i efterhand kunna utföra automatisk dokument analys och digitalisering med optisk teckenläsning. Vidare är convolutional neural network det främsta alternativet för bearbetning av dokument bilder medan recurrent neural network aldrig har använts för semantisk segmentering av dokument. Detta är intressant eftersom om vi tar hänsyn till hur ett recurrent neural network fungerar och att recurrent neural network har uppnått mycket bra resultat inom binär bearbetning av dokument, borde det likväl vara möjligt att använda ett recurrent neural network för semantisk segmentering av dokument och även här uppnå bra resultat.

    Syfte. Syftet med arbetet är att undersöka om ett recurrent neural network kan uppnå ett likvärdigt resultat jämfört med ett convolutional neural network för semantisk segmentering av dokument. Vidare är syftet även att undersöka om en kombination av ett convolutional neural network och ett recurrent neural network kan ge ett bättre resultat än att bara endast använda ett recurrent neural network.

    Metod. För att kunna avgöra om ett recurrent neural network är ett lämpligt alternativ för semantisk segmentering av dokument utvärderas prestanda resultatet för tre olika modeller av recurrent neural network. Därefter jämförs dessa resultat med prestanda resultatet för ett convolutional neural network. Vidare utförs förbehandling av bilder och multi klassificering för att modellerna i slutändan ska kunna producera mätbara resultat av uppskattnings bilder.

    Resultat. Genom att utvärdera prestanda resultaten för modellerna kan vi i en jämförelse med den bästa modellen och ett convolutional neural network uppmäta en prestanda skillnad på 2.7%. Noterbart i det här fallet är att den bästa modellen uppvisar en jämnare fördelning av prestanda. För de två modellerna som uppvisade en lägre prestanda kan slutsatsen dras att deras utfall beror på en lägre modell komplexitet. Vidare vid en jämförelse av dessa två modeller, där den ena har en kombination av ett convolutional neural network och ett recurrent neural network medan den andra endast har ett recurrent neural network uppmäts en prestanda skillnad på 4.9%.

    Slutsatser. Resultatet antyder att ett recurrent neural network förmodligen är ett lämpligt alternativ till ett convolutional neural network för semantisk segmentering av dokument. Vidare dras slutsatsen att en kombination av de båda varianterna bidrar till ett bättre prestanda resultat.

  • 29.
    Aivars, Sablis
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Benefits of transactive memory systems in large-scale development2016Självständigt arbete på avancerad nivå (masterexamen), 80 poäng / 120 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Context. Large-scale software development projects are those consisting of a large number of teams, maybe even spread across multiple locations, and working on large and complex software tasks. That means that neither a team member individually nor an entire team holds all the knowledge about the software being developed and teams have to communicate and coordinate their knowledge. Therefore, teams and team members in large-scale software development projects must acquire and manage expertise as one of the critical resources for high-quality work.

    Objectives. We aim at understanding whether software teams in different contexts develop transactive memory systems (TMS) and whether well-developed TMS leads to performance benefits as suggested by research conducted in other knowledge-intensive disciplines. Because multiple factors may influence the development of TMS, based on related TMS literature we also suggest to focus on task allocation strategies, task characteristics and management decisions regarding the project structure, team structure and team composition.

    Methods. We use the data from two large-scale distributed development companies and 9 teams, including quantitative data collected through a survey and qualitative data from interviews to measure transactive memory systems and their role in determining team performance. We measure teams’ TMS with a latent variable model. Finally, we use focus group interviews to analyze different organizational practices with respect to team management, as a set of decisions based on two aspects: team structure and composition, and task allocation.

    Results. Data from two companies and 9 teams are analyzed and the positive influence of well-developed TMS on team performance is found. We found that in large-scale software development, teams need not only well-developed team’s internal TMS, but also have well- developed and effective team’s external TMS. Furthermore, we identified practices that help of hinder development of TMS in large-scale projects.

    Conclusions. Our findings suggest that teams working in large-scale software development can achieve performance benefits if transactive memory practices within the team are supported with networking practices in the organization. 

  • 30.
    Akama-kisseh, Jerome
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kreativa teknologier.
    EXPLORING COMPUTERIZED TROUBLE TICKETING SYSTEM AND ITS BENEFITS IN VODAFONE GHANA2016Självständigt arbete på avancerad nivå (magisterexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Today more than ever, Computerized Trouble Ticketing System is becoming a booming information technology system that makes the difference between staying in business in a competitive global telecommunication arena.

    This quantitative exploratory survey utilised conveniently selected research subjects to explore computerized trouble ticketing system and its inherent benefits in Vodafone Ghana Plc. Cross section of vital data set collected with the aid of structured questionnaires haven been analyzed using descriptive statistics model.

    The study revealed that, effective and efficient usage of computerized trouble ticketing systems benefit the company in terms of its customer satisfaction, competitive advantage and business intelligence in competitive telecom arena. Nevertheless, the smooth realization of these inherent benefits are constantly challenged by complexity in managing volumes of data generated, intense era of competition, high cost of trouble ticketing system, as well as, rapid technological obsolesce in computerized trouble ticketing applications in telecommunication market.

    The study recommended for the quick and effective adoption of differentiation strategy, cost leadership strategy and customer relationship management, which are customer-centric measures that can build sustainable long-term customer relationship that can create value for the company, as well as, for the customers.

  • 31.
    Akkineni, Srinivasu
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    The impact of RE process factors and organizational factors during alignment between RE and V&V: Systematic Literature Review and Survey2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Context: Requirements engineering (RE) and Verification and validation (V&V) areas are treated to be integrated and assure successful development of the software project. Therefore, activation of both competences in the early stages of the project will support products in meeting the customer expectation regarding the quality and functionality. However, this quality can be achieved by aligning RE and V&V. There are different practices such as requirements, verification, validation, control, tool etc. that are followed by organizations for alignment and to address different challenges faced during the alignment between RE and V&V. However, there is a requisite for studies to understand the alignment practices, challenges and factors, which can enable successful alignment between RE and V&V.

    Objectives: In this study, an exploratory investigation is carried out to know the impact of factors i.e. RE process and organizational factors during the alignment between RE and V&V. The main objectives of this study are:

    1. To find the list of RE practices that facilitate alignment between RE and V&V.
    2. To categorize RE practices with respect to their requirement phases.
    3. To find the list of RE process and organizational factors that influence alignment between RE and V&V besides their impact.
    4. To identify the challenges that are faced during the alignment between RE and V&V.
    5. To obtain list of challenges that are addressed by RE practices during the alignment between RE and V&V.

    Methods: In this study Systematic Literature Review (SLR) is conducted using snowballing procedure to identify the relevant information about RE practices, challenges, RE process factors and organizational factors. The studies were captured from Engineering Village database. Rigor and relevance analysis is performed to assess the quality of the studies obtained through SLR. Further, a questionnaire intended for industrial survey was prepared from the gathered literature and distributed to practitioners from the software industry in order to collect empirical information about this study. Thereafter, data obtained from industrial survey was analyzed using statistical analysis and chi-square significance test.

    Results: 20 studies were identified through SLR, which are relevant to this study. After analyzing the obtained studies, the list of RE process factors, organizational factors, challenges and RE practices during alignment between RE and V&V are gathered. Thereupon, an industrial survey is conducted from the obtained literature, which has obtained 48 responses. Alignment between RE and V&V possess an impact of RE process factors and organizational factors and this is also mentioned by the respondents of the survey. Moreover, this study finds an additional RE process factors and organizational factors during the alignment between RE and V&V, besides their impact. Another contribution is, addressing the unaddressed challenges by RE practices obtained through the literature. Additionally, validation of categorized RE practices with respect to their requirement phases is carried out.

    Conclusions: To conclude, the obtained results from this study will benefit practitioners for capturing more insight towards the alignment between RE and V&V. This study identified the impact of RE process factors and organizational factors during the alignment between RE and V&V along with the importance of challenges faced during the alignment between RE and V&V. This study also addressed the unaddressed challenges by RE practices obtained through literature. Respondents of the survey believe that many RE process and organizational factors have negative impact on the alignment between RE and V&V based on the size of an organization. In addition to this, validation of results for applying RE practices at different requirement phases is toted through survey. Practitioners can identify the benefits from this research and researchers can extend this study to remaining alignment practices.

  • 32.
    Akser, M.
    et al.
    Ulster University, GBR.
    Bridges, B.
    Ulster University, GBR.
    Campo, G.
    Ulster University, GBR.
    Cheddad, Abbas
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Curran, K.
    Ulster University, GBR.
    Fitzpatrick, L.
    Ulster University, GBR.
    Hamilton, L.
    Ulster University, GBR.
    Harding, J.
    Ulster University, GBR.
    Leath, T.
    Ulster University, GBR.
    Lunney, T.
    Ulster University, GBR.
    Lyons, F.
    Ulster University, GBR.
    Ma, M.
    University of Huddersfield, GBR.
    Macrae, J.
    Ulster University, GBR.
    Maguire, T.
    Ulster University, GBR.
    McCaughey, A.
    Ulster University, GBR.
    McClory, E.
    Ulster University, GBR.
    McCollum, V.
    Ulster University, GBR.
    Mc Kevitt, P.
    Ulster University, GBR.
    Melvin, A.
    Ulster University, GBR.
    Moore, P.
    Ulster University, GBR.
    Mulholland, E.
    Ulster University, GBR.
    Muñoz, K.
    BijouTech, CoLab, Letterkenny, Co., IRL.
    O’Hanlon, G.
    Ulster University, GBR.
    Roman, L.
    Ulster University, GBR.
    SceneMaker: Creative technology for digital storytelling2018Ingår i: Lect. Notes Inst. Comput. Sci. Soc. Informatics Telecommun. Eng. / [ed] Brooks A.L.,Brooks E., Springer Verlag , 2018, Vol. 196, s. 29-38Konferensbidrag (Refereegranskat)
    Abstract [en]

    The School of Creative Arts & Technologies at Ulster University (Magee) has brought together the subject of computing with creative technologies, cinematic arts (film), drama, dance, music and design in terms of research and education. We propose here the development of a flagship computer software platform, SceneMaker, acting as a digital laboratory workbench for integrating and experimenting with the computer processing of new theories and methods in these multidisciplinary fields. We discuss the architecture of SceneMaker and relevant technologies for processing within its component modules. SceneMaker will enable the automated production of multimodal animated scenes from film and drama scripts or screenplays. SceneMaker will highlight affective or emotional content in digital storytelling with particular focus on character body posture, facial expressions, speech, non-speech audio, scene composition, timing, lighting, music and cinematography. Applications of SceneMaker include automated simulation of productions and education and training of actors, screenwriters and directors. © ICST Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2017.

  • 33.
    Alahmad, Yazan
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för teknik och estetik.
    Gender-Bending in Massively Multiplayer Online Role-playing Games: Reasons & Consequences of gender-bending2015Självständigt arbete på grundnivå (kandidatexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
  • 34.
    Alahyari, Hiva
    et al.
    Chalmers; Göteborgs Universitet, SWE.
    Berntsson Svensson, Richard
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Gorschek, Tony
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    A study of value in agile software development organizations2017Ingår i: Journal of Systems and Software, ISSN 0164-1212, E-ISSN 1873-1228, Vol. 125, s. 271-288Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The Agile manifesto focuses on the delivery of valuable software. In Lean, the principles emphasise value, where every activity that does not add value is seen as waste. Despite the strong focus on value, and that the primary critical success factor for software intensive product development lies in the value domain, no empirical study has investigated specifically what value is. This paper presents an empirical study that investigates how value is interpreted and prioritised, and how value is assured and measured. Data was collected through semi-structured interviews with 23 participants from 14 agile software development organisations. The contribution of this study is fourfold. First, it examines how value is perceived amongst agile software development organisations. Second, it compares the perceptions and priorities of the perceived values by domains and roles. Third, it includes an examination of what practices are used to achieve value in industry, and what hinders the achievement of value. Fourth, it characterises what measurements are used to assure, and evaluate value-creation activities.

  • 35.
    Alahyari, Hiva
    et al.
    Chalmers, SWE.
    Gorschek, Tony
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Berntsson Svensson, Richard
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    An exploratory study of waste in software development organizations using agile or lean approaches: A multiple case study at 14 organizations2019Ingår i: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 107, s. 78-94Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Context: The principal focus of lean is the identification and elimination of waste from the process with respect to maximizing customer value. Similarly, the purpose of agile is to maximize customer value and minimize unnecessary work and time delays. In both cases the concept of waste is important. Through an empirical study, we explore how waste is approached in agile software development organizations. Objective: This paper explores the concept of waste in agile/lean software development organizations and how it is defined, used, prioritized, reduced, or eliminated in practice Method: The data were collected using semi-structured open-interviews. 23 practitioners from 14 embedded software development organizations were interviewed representing two core roles in each organization. Results: Various wastes, categorized in 10 different categories, were identified by the respondents. From the mentioned wastes, not all were necessarily waste per se but could be symptoms caused by wastes. From the seven wastes of lean, Task-switching was ranked as the most important, and Extra-features, as the least important wastes according to the respondents’ opinion. However, most companies do not have their own or use an established definition of waste, more importantly, very few actively identify or try to eliminate waste in their organizations beyond local initiatives on project level. Conclusion: In order to identify, recognize and eliminate waste, a common understanding, and a joint and holistic view of the concept is needed. It is also important to optimize the whole organization and the whole product, as waste on one level can be important on another, thus sub-optimization should be avoided. Furthermore, to achieve a sustainable and effective waste handling, both the short-term and the long-term perspectives need to be considered. © 2018 Elsevier B.V.

  • 36.
    Albinsson, Mattias
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Andersson, Linus
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Improving Quality of Experience through Performance Optimization of Server-Client Communication2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    I programvaruteknik är det viktigt att överväga hur en potentiell användare upplever ett system vid användning. Ingen användare kommer att ha en tillfredsställande upplevelse om de uppfattar systemet som långsamt, icke responsivt, ostabilt eller döljande av information. Dessutom, om systemet binder användarna till ett begränsat antal möjliga handlingar, kommer deras upplevelse vidare försämras. För att utvärdera vilken påverkan dessa problem har på en användares upplevda kvalitet, används mätenheten Upplevd Tjänstekvalitet.

    I detta arbete var det huvudsakliga syftet att förbättra en användares upplevelse av ett system som led av de tidigare nämnda problemen vid sökning av större datamängder. För att uppnå detta syfte utvärderades systemet för att identifiera befintliga problem samt vilka som mest påverkade användares Upplevda Tjänstekvalitet. Systemet som utvärderades var en mjukvara för lagerhantering som utvecklades och underhölls av Aptean AB‟s kontor i Hässleholm, Sverige. Systemet bestod av flera klienter och en server som skickade data över ett nätverk. Systemet utvärderades med en fallstudie där prestandan anayserades tillsammans med en enkät utförd i samarbete med Apteans personal för att få insikt i hur systemet upplevdes vid sökningar av stora datamängder. Resultaten visade på tre problem som hade störst inverkan på den Upplevda Tjänstekvaliteten: (1) interaktion; begränsade antal möjliga handlingar under en sökning, (2) transparens; begränsad tillgång till information om sökningens progress samt den hämtade datan, (3) körningstid; slutförande av en sökning tog lång tid.

    Efter att systemet hade analyserats, implementerades hypotetiska teknologiska lösningar för att lösa de identifierade problemen. Den första lösningen delade in datan i ett flertal partitioner, den andra minskade datans storlek som skickades över nätverket genom att tillämpa komprimering och den tredje var en kombination av de två teknologierna. Efter implementationen utfördes en sista uppsättning mätningar tillsammans med enkäten för att jämföra lösningarna baserat på deras prestanda och förbättringar av Upplevd Tjänstekvalitet.

    Den mest signifikanta förbättringen av Upplevd Tjänstekvalitet kom från datapartitioneringslösningen. Trots att kombinationen av lösningar uppnådde en mindre vidare förbättring, var det primärt tack vare datapartitioneringen, vilket innebar att den teknologin var den mest passande lösningen till de identifierade problemen jämfört med komprimering, vilken visade på endast en liten förbättring av Upplevd Tjänstekvalitet. När data partitionerades kunde flera uppdateringar skickas och användaren tilläts ett större antal möjliga handlingar under en sökning, men också en förbättrad tillgång till information i klienten angående sökningens progress samt den hämtade datan. Trots att datapartitionering inte förbättrade körningstiden, kunde den erbjuda användaren en första mängd data snabbt utan att tvinga användaren att sysslolöst vänta, vilket gjorde att systemet upplevdes som snabbt. För att förbättra den Upplevda Tjänstekvaliteten för system med server-klient kommunikation visade resultaten att datapartitionering är en lösning som erbjöd flera möjligheter för förbättring.

  • 37. Alegroth, Emil
    et al.
    Feldt, Robert
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Kolstrom, Pirjo
    Maintenance of automated test suites in industry: An empirical study on Visual GUI Testing2016Ingår i: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 73, s. 66-80Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Context: Verification and validation (V&V) activities make up 20-50% of the total development costs of a software system in practice. Test automation is proposed to lower these V&V costs but available research only provides limited empirical data from industrial practice about the maintenance costs of automated tests and what factors affect these costs. In particular, these costs and factors are unknown for automated GUI-based testing. Objective: This paper addresses this lack of knowledge through analysis of the costs and factors associated with the maintenance of automated GUI-based tests in industrial practice. Method: An empirical study at two companies, Siemens and Saab, is reported where interviews about, and empirical work with, Visual GUI Testing is performed to acquire data about the technique's maintenance costs and feasibility. Results: 13 factors are observed that affect maintenance, e.g. tester knowledge/experience and test case complexity. Further, statistical analysis shows that developing new test scripts is costlier than maintenance but also that frequent maintenance is less costly than infrequent, big bang maintenance. In addition a cost model, based on previous work, is presented that estimates the time to positive return on investment (ROI) of test automation compared to manual testing. Conclusions: It is concluded that test automation can lower overall software development costs of a project while also having positive effects on software quality. However, maintenance costs can still be considerable and the less time a company currently spends on manual testing, the more time is required before positive, economic, ROI is reached after automation. (C) 2016 Elsevier B.V. All rights reserved.

  • 38. Alegroth, Emil
    et al.
    Feldt, Robert
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Ryrholm, Lisa
    Visual GUI testing in practice: challenges, problems and limitations2015Ingår i: Journal of Empirical Software Engineering, ISSN 1382-3256, E-ISSN 1573-7616, Vol. 20, nr 3, s. 694-744Artikel i tidskrift (Refereegranskat)
    Abstract [sv]

    Vi presenterar utmaningar med att använda visuell GUI testning i industriell programvaruteknik.

  • 39.
    Aleksandr, Polescuk
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för datalogi och datorsystemteknik.
    Linking Residential Burglaries using the Series Finder Algorithm in a Swedish Context2017Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Context. A minority of criminals performs a majority of the crimes today. It is known that every criminal or group of offenders to some extent have a particular pattern (modus operandi) how crime is performed. Therefore, computers' computational power can be employed to discover crimes that have the same model and possibly are carried out by the same criminal. The goal of this thesis was to apply the existing Series Finder algorithm to a feature-rich dataset containing data about Swedish residential burglaries.

    Objectives. The following objectives were achieved to complete this thesis: Modifications performed on an existing Series Finder implementation to fit the Swedish police forces dataset and MatLab code converted to Python. Furthermore, experiment setup designed with appropriate metrics and statistical tests. Finally, modified Series Finder implementation's evaluation performed against both Spatial-Temporal and Random models.

    Methods. The experimental methodology was chosen in order to achieve the objectives. An initial experiment was performed to find right parameters to use for main experiments. Afterward, a proper investigation with dependent and independent variables was conducted.

    Results. After the metrics calculations and the statistical tests applications, the accurate picture revealed how each model performed. Series Finder showed better performance than a Random model. However, it had lower performance than the Spatial-Temporal model. The possible causes of one model performing better than another are discussed in analysis and discussion section.

    Conclusions. After completing objectives and answering research questions, it could be clearly seen how the Series Finder implementation performed against other models. Despite its low performance, Series Finder still showed potential, as presented in future work.

  • 40.
    Ali, Nauman Bin
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Is effectiveness sufficient to choose an intervention?: Considering resource use in empirical software engineering2016Ingår i: Proceedings of the 10th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement, ESEM 2016, Ciudad Real, Spain, September 8-9, 2016, 2016, artikel-id 54Konferensbidrag (Refereegranskat)
  • 41.
    Ali, Nauman bin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Engström, Emelie
    Lund University, SWE.
    Taromirad, Masoumeh
    Halmstad University, SWE.
    Mousavi, Muhammad Raza
    Halmstad University, SWE.
    Minhas, Nasir Mehmood
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Helgesson, Daniel
    Lund University, SWE.
    Kunze, Sebastian
    Halmstad University, SWE.
    Varshosaz, Mahsa
    Halmstad University, SWE.
    On the search for industry-relevant regression testing research2019Ingår i: Journal of Empirical Software Engineering, ISSN 1382-3256, E-ISSN 1573-7616Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Regression testing is a means to assure that a change in the software, or

    its execution environment, does not introduce new defects. It involves the expensive

    undertaking of rerunning test cases. Several techniques have been proposed

    to reduce the number of test cases to execute in regression testing, however, there

    is no research on how to assess industrial relevance and applicability of such techniques.

    We conducted a systematic literature review with the following two goals:

    rstly, to enable researchers to design and present regression testing research with

    a focus on industrial relevance and applicability and secondly, to facilitate the industrial

    adoption of such research by addressing the attributes of concern from the

    practitioners' perspective. Using a reference-based search approach, we identied

    1068 papers on regression testing. We then reduced the scope to only include papers

    with explicit discussions about relevance and applicability (i.e. mainly studies

    involving industrial stakeholders). Uniquely in this literature review, practitioners

    were consulted at several steps to increase the likelihood of achieving our aim of

    identifying factors important for relevance and applicability. We have summarised

    the results of these consultations and an analysis of the literature in three taxonomies,

    which capture aspects of industrial-relevance regarding the regression

    testing techniques. Based on these taxonomies, we mapped 38 papers reporting

    the evaluation of 26 regression testing techniques in industrial settings.

  • 42.
    Ali, Nauman bin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Petersen, Kai
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    FLOW-assisted value stream mapping in the early phases of large-scale software development2016Ingår i: Journal of Systems and Software, ISSN 0164-1212, E-ISSN 1873-1228, Vol. 111, s. 213-227Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Value stream mapping (VSM) has been successfully applied in the context of software process improvement. However, its current adaptations from Lean manufacturing focus mostly on the flow of artifacts and have taken no account of the essential information flows in software development. A solution specifically targeted toward information flow elicitation and modeling is FLOW. This paper aims to propose and evaluate the combination of VSM and FLOW to identify and alleviate information and communication related challenges in large-scale software development. Using case study research, FLOW-assisted VSM was used for a large product at Ericsson AB, Sweden. Both the process and the outcome of FLOW-assisted VSM have been evaluated from the practitioners’ perspective. It was noted that FLOW helped to systematically identify challenges and improvements related to information flow. Practitioners responded favorably to the use of VSM and FLOW, acknowledged the realistic nature and impact on the improvement on software quality, and found the overview of the entire process using the FLOW notation very useful. The combination of FLOW and VSM presented in this study was successful in systematically uncovering issues and characterizing their solutions, indicating their practical usefulness for waste removal with a focus on information flow related issues.

  • 43.
    Ali, Nauman bin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Usman, Muhammad
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    A critical appraisal tool for systematic literature reviews in software engineering2019Ingår i: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 112, s. 48-50Artikel, forskningsöversikt (Refereegranskat)
    Abstract [en]

    Context: Methodological research on systematic literature reviews (SLRs)in Software Engineering (SE)has so far focused on developing and evaluating guidelines for conducting systematic reviews. However, the support for quality assessment of completed SLRs has not received the same level of attention. Objective: To raise awareness of the need for a critical appraisal tool (CAT)for assessing the quality of SLRs in SE. To initiate a community-based effort towards the development of such a tool. Method: We reviewed the literature on the quality assessment of SLRs to identify the frequently used CATs in SE and other fields. Results: We identified that the CATs currently used is SE were borrowed from medicine, but have not kept pace with substantial advancements in the field of medicine. Conclusion: In this paper, we have argued the need for a CAT for quality appraisal of SLRs in SE. We have also identified a tool that has the potential for application in SE. Furthermore, we have presented our approach for adapting this state-of-the-art CAT for assessing SLRs in SE. © 2019 The Authors

  • 44.
    Ali, Nauman bin
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Usman, Muhammad
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Reliability of search in systematic reviews: Towards a quality assessment framework for the automated-search strategy2018Ingår i: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, ISSN 0950-5849, Vol. 99, s. 133-147Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Context: The trust in systematic literature reviews (SLRs) to provide credible recommendations is critical for establishing evidence-based software engineering (EBSE) practice. The reliability of SLR as a method is not a given and largely depends on the rigor of the attempt to identify, appraise and aggregate evidence. Previous research, by comparing SLRs on the same topic, has identified search as one of the reasons for discrepancies in the included primary studies. This affects the reliability of an SLR, as the papers identified and included in it are likely to influence its conclusions. Objective: We aim to propose a comprehensive evaluation checklist to assess the reliability of an automated-search strategy used in an SLR. Method: Using a literature review, we identified guidelines for designing and reporting automated-search as a primary search strategy. Using the aggregated design, reporting and evaluation guidelines, we formulated a comprehensive evaluation checklist. The value of this checklist was demonstrated by assessing the reliability of search in 27 recent SLRs. Results: Using the proposed evaluation checklist, several additional issues (not captured by the current evaluation checklist) related to the reliability of search in recent SLRs were identified. These issues severely limit the coverage of literature by the search and also the possibility to replicate it. Conclusion: Instead of solely relying on expensive replications to assess the reliability of SLRs, this work provides means to objectively assess the likely reliability of a search-strategy used in an SLR. It highlights the often-assumed aspect of repeatability of search when using automated-search. Furthermore, by explicitly considering repeatability and consistency as sub-characteristics of a reliable search, it provides a more comprehensive evaluation checklist than the ones currently used in EBSE. © 2018 Elsevier B.V.

  • 45.
    Ali, Nauman
    et al.
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Petersen, Kai
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Evaluating strategies for study selection in systematic literature studies2014Ingår i: ESEM '14 Proceedings of the 8th ACM/IEEE International Symposium on Empirical Software Engineering and Measurement, ACM , 2014, Vol. article 45Konferensbidrag (Refereegranskat)
    Abstract [en]

    Context: The study selection process is critical to improve the reliability of secondary studies. Goal: To evaluate the selection strategies commonly employed in secondary studies in software engineering. Method: Building on these strate- gies, a study selection process was formulated and evalu- ated in a systematic review. Results: The selection process used a more inclusive strategy than the one typically used in secondary studies, which led to additional relevant articles. Conclusions: The results indicates that a good-enough sam- ple could be obtained by following a less inclusive but more efficient strategy, if the articles identified as relevant for the study are a representative sample of the population, and there is a homogeneity of results and quality of the articles.

  • 46.
    Alibabaei, Navid
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Wireless Mesh Networks: a comparative study of Ad-Hoc routing protocols toward more efficient routing2015Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Each day, the dream of seamless networking and connectivity everywhere is getting closer to become a reality. In this regard, mobile Ad-Hoc networks (MANETs) have been a hot topic in the last decade; but the amount of MANET usage nowadays confines to a tiny percentage of all our network connectivity in our everyday life, which connectivity through infrastructured networks has the major share. On the other hand, we know that future of networking belongs to Ad-Hocing , so for now we try to give our everyday infrastructure network a taste of Ad-Hocing ability; these types of networks are called Wireless Mesh Networks (WMN) and routing features play a vital role in their functionality. In this thesis we examine the functionality of 3 Ad-Hoc routing protocols known as AODV, OLSR and GRP using simulation method in OPNET17.5. For this goal we set up 4 different scenarios to examine the performance of these routing protocols; these scenarios vary from each other in amount of nodes, background traffic and mobility of the nodes. Performance measurements of these protocols are done by network throughput, end-end delay of the transmitted packets and packet loss ratio as our performance metrics. After the simulation run and gathering the results we study them in a comparative view, first based on each scenario and then based on each protocol. For conclusion, as former studies suggest AODV, OLSR and DRP are among the best routing protocols for WMNs, so in this research we don’t introduce the best RP based on the obtained functionality results, instead we discuss the network conditions that each of these protocols show their best functionality in them and suggest the best routing mechanism for different networks based on the analysis from the former part.  

  • 47.
    Allberg, Petrus
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Applied machine learning in the logistics sector: A comparative analysis of supervised learning algorithms2018Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    BackgroundMachine learning is an area that is being explored with great haste these days, which inspired this study to investigate how seven different supervised learning algorithms perform compared to each other. These algorithms were used to perform classification tasks on logistics consignments, the classification is binary and a consignment can either be classified as missed or not.

    ObjectivesThe goal was to find which of these algorithms perform well when used for this classification task and to see how the results varied with different sized datasets. Importance of the features which were included in the datasets has been analyzed with the intention of finding if there is any connection between human errors and these missed consignments.

    MethodsThe process from raw data to a predicted classification has many steps including data gathering, data preparation, feature investigation and more. Through cross-validation, the algorithms were all trained and tested upon the same datasets and then evaluated based on the metrics recall and accuracy.

    ResultsThe scores on both metrics increase with the size of the datasets, and when comparing the seven algorithms, two does not perform equally compared to the other five, which all perform moderately the same.

    Conclusions Any of the five algorithms mentioned prior can be chosen for this type of classification, or to further study based on other measurements, and there is an indication that human errors could play a part on whether a consignment gets classified as missed or not.

  • 48.
    Almroth, Tobias
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för programvaruteknik.
    Data visualization for the modern web: A look into tools and techniques for visualizing data in Angular 5 applications2018Självständigt arbete på grundnivå (högskoleexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [en]

    This paper looks into how data is best visualized and how visualizations should be designed to be most easily perceived. Furthermore the study looks into what tools there are available on the market today for visualizing data in angular 5 applications. With regards to a client, a developer team from the swedish police IT-department, the tools are evaluated and the one most suitable for the client is found. The paper also looks into how a dynamic data solution can be developed in angular 5. A solution where data can be selected in one component and displayed in another.

    To answer the questions sought a study of previous research into data visualization was done as well as a look into how angular 5 applications can be developed. Interviews with the clients were held where their specific requirements on visualization tools were identified. After searching and listing available visualization tools on the market the tools were evaluated against the clients requirements and a prototype application were developed. Showcasing both the most suitable tool and its integration but also a dynamic data solution in angular 5.

    As a conclusion data visualizations should be made as simple as possible with the main focus on the data. When it comes to tools the one most suitable to the client was Chart.js that easily integrated into an angular 5 application. An application that thanks to angular’s features is well equipped for handling and developing dynamic data solutions.

  • 49.
    Altaf, Moaz
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    SMI-S for the Storage Area Network (SAN) Management2014Studentuppsats (Examensarbete)
    Abstract [en]

    The storage vendors have their own standards for the management of their storage resources but it creates interoperability issues on different storage products. With the recent advent of the new protocol named Storage Management Initiative-Specification (SMI-S), the Storage Networking Industry Association (SNIA) has taken a major step in order to make the storage management more effective and organized. SMI-S has replaced its predecessor Storage Network Management Protocol (SNMP) and it has been categorized as an ISO standard. The main objective of the SMI-S is to provide interoperability management of the heterogeneous storage vendor systems by unifying the Storage Area Network (SAN) management, hence making the dreams of the network managers come true. SMI-S is a guide to build systems using modules that ‘plug’ together. SMI-S compliant storage modules that use CIM ‘language’ and adhere to CIM schema interoperate in a system regardless of which vendor built them. SMI-S is object-oriented, any physical or abstract storage-related elements can be defined as a CIM object. SMI-S can unify the SAN management systems and it works well with the heterogeneous storage environment. SMI-S has offered a cross-platform, cross-vendor storage resource management. This thesis work discusses the use of SMI-S at Compuverde which is a storage solution provider, located in the heart of the Karlskrona, the southeastern part of Sweden. Compuverde was founded by Stefan Bernbo in Karlskrona,Sweden. Just like all others leading storage providers, Compuverde has also decided to deploy the Storage Management Initiative-Specification (SMI-S) to manage their Storage Area Network (SAN) and to achieve interoperability. This work was done to help Compuverde to deploy the SMI-S protocol for the management of the Storage Area Network (SAN) which, among many of its features, would create alerts/traps in case of a disk failure in the SAN. In this way, they would be able to keep the data of their clients, safe and secure and keep their reputation for being reliable in the storage industry. Since Compuverde regularly use Microsoft Windows and Microsoft have started to support SMI-S for storage provisioning in System Center 2012 Virtual Machine Manager (SCVMM), this work was done using the SCVMM 2012 and the Windows Server 2012.The SMI-S provider which was used for this work was QNAP TS- 469 Pro.

  • 50.
    Aluguri, Tarun
    Blekinge Tekniska Högskola, Fakulteten för datavetenskaper, Institutionen för kommunikationssystem.
    Performance Evaluation of OpenStack Deployment Tools2016Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    Cloud computing enables on-demand access to a shared pool of computing resources, that can beeasily provisioned, configured and released with minimal management cost and effort. OpenStack isan open source cloud management platform aimed at providing private or public IaaS cloud onstandard hardware. Since, deploying OpenStack manually is tedious and time-consuming, there are several tools that automate the deployment of OpenStack. Usually, cloud admins choose a tool basedon its level of automation, ease of use or interoperability with existing tools used by them. However,another desired factor while choosing a deployment tool is its deployment speed. Cloud admins cannot select based on this factor since, there is no previous work on the comparison of deploymenttools based on deployment time. This thesis aims to address this issue.

    The main aim of the thesis is to evaluate the performance of OpenStack deployment tools with respectto operating system provisioning and OpenStack deployment time, on physical servers. Furthermore,the effect of varying number of nodes, OpenStack architecture deployed and resources (cores andRAM) provided to deployment node on provisioning and deployment times, is also analyzed. Also,the tools classified based on stages of deployment and method of deploying OpenStack services. In this thesis we evaluate the performance of MAAS, Foreman, Mirantis Fuel and Canonical Autopilot.

    The performance of the tools is measured via experimental research method. Operating system provisioning time and OpenStack deployment times are measured while varying the number of nodes/OpenStack architecture and resources provided to deployment node i.e. cores and RAM.

    Results show that provisioning time of MAAS is less than Mirantis Fuel, which is less than Foreman.Furthermore, for all 3 tools as number of nodes increases provisioning time increases. However, the amount of increase is lowest for MAAS than Mirantis Fuel and Foreman. Similarly, results for baremetal OpenStack deployment time show that, Canonical Autopilot outperforms Mirantis Fuel by asignificant difference for all OpenStack scenarios considered. Furthermore, as number of nodes in an OpenStack scenario increases, the deployment time for both the tools increases.

    From the research, it is concluded that MAAS and Canonical Autopilot perform better as provisioningand bare metal OpenStack deployment tool respectively, than other tools that have been analyzed.Furthermore, from the analysis it can be concluded that increase in number of nodes/ OpenStackarchitecture, leads to an increase in both provisioning time and OpenStack deployment time for all the tools.

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