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  • 1.
    Abbas, Muhammad Tahir
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Jibran, Muhammad Ali
    Jeju Natl Univ, Dept Comp Engn, Jeju 63243, South Korea..
    Afaq, Muhammad
    Sarhad Univ Sci & Informat Technol, Pakistan..
    Song, Wang-Cheol
    Jeju Natl Univ, South Korea..
    An adaptive approach to vehicle trajectory prediction using multimodel Kalman filterInngår i: European transactions on telecommunications, ISSN 1124-318X, E-ISSN 2161-3915, artikkel-id e3734Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    With the aim to improve road safety services in critical situations, vehicle trajectory and future location prediction are important tasks. An infinite set of possible future trajectories can exit depending on the current state of vehicle motion. In this paper, we present a multimodel-based Extended Kalman Filter (EKF), which is able to predict a set of possible scenarios for vehicle future location. Five different EKF models are proposed in which the current state of a vehicle exists, particularly, a vehicle at intersection or on a curve path. EKF with Interacting Multiple Model framework is explored combinedly for mathematical model creation and probability calculation for that model to be selected for prediction. Three different parameters are considered to create a state vector matrix, which includes vehicle position, velocity, and distance of the vehicle from the intersection. Future location of a vehicle is then used by the software-defined networking controller to further enhance the safety and packet delivery services by the process of flow rule installation intelligently to that specific area only. This way of flow rule installation keeps the controller away from irrelevant areas to install rules, hence, reduces the network overhead exponentially. Proposed models are created and tested in MATLAB with real-time global positioning system logs from Jeju, South Korea.

  • 2.
    Abdollahi, Kamran
    et al.
    Computer and Science Department Iran University of Science and Technology Tehran, Iran.
    Shams Shafigh, Alireza
    Computer and Science Department Iran University of Science and Technology Tehran, Iran.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Improving Performance of On Demand Multicast Routing by deleting lost join query packet2010Inngår i: Proceedings of The Sixth Advanced International Conference on Telecommunications - AICT 2010, IEEE conference proceedings, 2010, s. 316-322Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A Mobile ad hoc network is a collection of wireless nodes that dynamically organize themselves to form a network without the need for any fixed infrastructure or centralized administration. The network topology dynamically changes frequently in an unpredictable manner since nodes are free to move. Support for multicasting is essential in such environment as it is considered to be an efficient way to deliver information from source nodes to many client nodes. A problem with multicast routing algorithms is their efficiency as their forwarding structure determines the overall network resource consumption makes them significantly less efficient than unicast routing algorithms. In this research, we improve the performance of the popular ODMRP multicast routing protocol by restricting the domain of join query packets, which have been lost. This is achieved by augmenting the join query packets with minimum extra information (one field), which denotes the number of the visited node from previous forwarding group. Simulation results show, that our mechanisms significantly reduce the control traffic and thus the overall latency and power consumption in the network.

  • 3.
    Aboueata, N.
    et al.
    Qatar University, Doha, Qatar.
    Alrasbi, S.
    Qatar University, Doha, Qatar.
    Erbad, A.
    Qatar University, Doha, Qatar.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Bhamare, Deval
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Supervised machine learning techniques for efficient network intrusion detection2019Inngår i: Proceedings - International Conference on Computer Communications and Networks, ICCCN, Institute of Electrical and Electronics Engineers Inc. , 2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Cloud computing is gaining significant traction and virtualized data centers are becoming popular as a cost-effective infrastructure in telecommunication industry. Infrastructure as a Service (IaaS), Platform as a Service (PaaS) and Software as a Service (SaaS) are being widely deployed and utilized by end users, including many private as well as public organizations. Despite its wide-spread acceptance, security is still the biggest threat in cloud computing environments. Users of cloud services are under constant fear of data loss, security breaches, information theft and availability issues. Recently, learning-based methods for security applications are gaining popularity in the literature with the advents in machine learning (ML) techniques. In this work, we explore applicability of two well-known machine learning approaches, which are, Artificial Neural Networks (ANN) and Support Vector Machines (SVM), to detect intrusions or anomalous behavior in the cloud environment. We have developed ML models using ANN and SVM techniques and have compared their performances. We have used UNSW-NB-15 dataset to train and test the models. In addition, we have performed feature engineering and parameter tuning to find out optimal set of features with maximum accuracy to reduce the training time and complexity of the ML models. We observe that with proper features set, SVM and ANN techniques have been able to achieve anomaly detection accuracy of 91% and 92% respectively, which is higher compared against that of the one achieved in the literature, with reduced number of features needed to train the models.

  • 4.
    Abrahamsson, Henrik
    et al.
    RISE SICS.
    Abdesslem, Fehmi Ben
    RISE SICS.
    Ahlgren, Bengt
    RISE SICS.
    Björkman, Mats
    Mälardalen University.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Marsh, Ian
    RISE SICS.
    Selecting Operator in 3G/4G Networks for Time-Critical C-ITS Applications2018Konferansepaper (Fagfellevurdert)
  • 5.
    Abrahamsson, Henrik
    et al.
    RISE SICS, Stockholm, Sweden.
    Ben Abdesslem, Fehmi
    RISE SICS, Stockholm, Sweden.
    Ahlgren, Bengt
    RISE SICS, Stockholm, Sweden.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Marsh, Ian
    RISE SICS, Stockholm, Sweden.
    Bjorkman, Mats
    Mälardalens högskola.
    Connected Vehicles in Cellular Networks: Multi-access versus Single-access Performance2018Inngår i: 2018 NETWORK TRAFFIC MEASUREMENT AND ANALYSIS CONFERENCE (TMA), IEEE, 2018Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Connected vehicles can make roads traffic safer and more efficient, but require the mobile networks to handle time-critical applications. Using the MONROE mobile broadband measurement testbed we conduct a multi-access measurement study on buses. The objective is to understand what network performance connected vehicles can expect in today's mobile networks, in terms of transaction times and availability. The goal is also to understand to what extent access to several operators in parallel can improve communication performance. In our measurement experiments we repeatedly transfer warning messages from moving buses to a stationary server. We triplicate the messages and always perform three transactions in parallel over three different cellular operators. This creates a dataset with which we can compare the operators in an objective way and with which we can study the potential for multi-access. In this paper we use the triple-access dataset to evaluate single-access selection strategies, where one operator is chosen for each transaction. We show that if we have access to three operators and for each transaction choose the operator with best access technology and best signal quality then we can significantly improve availability and transaction times compared to the individual operators. The median transaction time improves with 6% compared to the best single operator and with 61% compared to the worst single operator. The 90-percentile transaction time improves with 23% compared to the best single operator and with 65% compared to the worst single operator.

  • 6. Abu Bakar, Sakhinah
    et al.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Characterization of essential proteins in proteins interaction networks2013Inngår i: Journal of Quality Measurement and Analysis, ISSN 1823-5670, Vol. 9, nr 2, s. 11-26Artikkel i tidsskrift (Fagfellevurdert)
  • 7.
    Acklehl, Azmy S.
    et al.
    Univ Louisiana Lafayette, Lafayette, LA USA..
    Colombo, Rinaldo Ni.
    Univ Brescia, Brescia, Italy..
    Goatinl, Paola
    Univ Cote Azur, CNRS, LIAD, Inria, Sophia Antiolis, France..
    Hille, Sander
    Leiden Univ, Leiden, Netherlands..
    Muntean, Adrian
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Special issue: Mathematical Modeling with Measures: Preface2020Inngår i: Mathematical Biosciences and Engineering, ISSN 1547-1063, E-ISSN 1551-0018, Vol. 17, nr 3, s. 2451-2452Artikkel i tidsskrift (Annet vitenskapelig)
  • 8.
    Adams, Paul C.
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Institutionen för geografi, medier och kommunikation (from 2013). University of Texas at Austin, USA.
    Geographies of media and communication II: Arcs of communication2018Inngår i: Progress in Human Geography, ISSN 0309-1325, E-ISSN 1477-0288, Vol. 42, nr 4, s. 590-599Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Some of the most perceptive contributions to the geographic study of media and communication have been in areas of landscapes studies and geohumanities. To bring landscape and geohumanities insights together more explicitly with communication and media, this progress report draws on George Revill’s concept of an ‘arc of sound’, expanding the concept’s scope to an arc of communication – a dynamic trajectory connecting one vantage point to another through various translations and shifts. It is a mix of integration and translation that forms its own space, place and time, integrating elements of embodied performance, multiple sensory modalities, temporality, absence and excess. Arcs of communication often depend on collaboration and can produce transformations of identity. The concept of the arc of communication enables discovery of numerous threads connecting landscape studies to geohumanities while deepening geographical understandings of media and communication.

  • 9. Adams, Robin
    et al.
    Fischer, Sally
    Pears, Arnold
    Börstler, Jürgen
    Boustedt, Jonas
    Dalenius, Peter
    Eken, Gunilla
    Heyer, Tim
    Jacobsson, Andreas
    Lindberg, Vanja
    Molin, Bemgt
    Moström, Jan-Erik
    Wiggberg, Mattias
    What is the Word for "Engineering" in Swedisch: Swedish Students Conceptions of their Discipline2007Rapport (Fagfellevurdert)
  • 10.
    Adamsson, Tim
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Handelshögskolan.
    Kravrekommendation: En undersökning för kravrekommendationer för Nya Intranätets forum på Karlstad Universitet2014Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Fulltekst (pdf)
    Adamsson Tim, Kravrekommendationer
  • 11.
    Afzal, Zeeshan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Towards Secure Multipath TCP Communication2017Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    The evolution in networking coupled with an increasing demand to improve user experience has led to different proposals to extend the standard TCP. Multipath TCP (MPTCP) is one such extension that has the potential to overcome few inherent limitations in the standard TCP. While MPTCP's design and deployment progresses, most of the focus has been on its compatibility. The security aspect is confined to making sure that the MPTCP protocol itself offers the same security level as the standard TCP.

    The topic of this thesis is to investigate the unexpected security implications raised by using MPTCP in the traditional networking environment. The Internet of today has security middle-boxes that perform traffic analysis to detect intrusions and attacks. Such middle-boxes make use of different assumptions about the traffic, e.g., traffic from a single connection always arrives along the same path. This along with many other assumptions may not be true anymore with the advent of MPTCP as traffic can be fragmented and sent over multiple paths simultaneously.

    We investigate how practical it is to evade a security middle-box by fragmenting and sending traffic across multiple paths using MPTCP. Realistic attack traffic is used to evaluate such attacks against Snort IDS to show that these attacks are feasible. We then go on to propose possible solutions to detect such attacks and implement them in an MPTCP proxy. The proxy aims to extend the MPTCP performance advantages to servers that only support standard TCP, while ensuring that intrusions can be detected as before. Finally, we investigate the potential MPTCP scenario where security middle-boxes only have access to some of the traffic. We propose and implement an algorithm to perform intrusion detection in such situations and achieve a nearly 90% detection accuracy. Another contribution of this work is a tool, that converts IDS rules into equivalent attack traffic to automate the evaluation of a middle-box.

    Fulltekst (pdf)
    fulltext
    Download (jpg)
    omslag
  • 12.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Garcia, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Partial Signature Matching in an MPTCP World using Insert-only Levenshtein DistanceManuskript (preprint) (Annet vitenskapelig)
  • 13.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Garcia, Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Slice Distance: An Insert-Only Levenshtein Distance with a Focus on Security Applications2018Inngår i: Proceedings of NTMS 2018 Conference and Workshop, New York: IEEE, 2018, s. 1-5Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Levenshtein distance is well known for its use in comparing two strings for similarity. However, the set of considered edit operations used when comparing can be reduced in a number of situations. In such cases, the application of the generic Levenshtein distance can result in degraded detection and computational performance. Other metrics in the literature enable limiting the considered edit operations to a smaller subset. However, the possibility where a difference can only result from deleted bytes is not yet explored. To this end, we propose an insert-only variation of the Levenshtein distance to enable comparison of two strings for the case in which differences occur only because of missing bytes. The proposed distance metric is named slice distance and is formally presented and its computational complexity is discussed. We also provide a discussion of the potential security applications of the slice distance.

    Fulltekst (pdf)
    fulltext
  • 14.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Automated Testing of IDS Rules2015Inngår i: Software Testing, Verification and Validation Workshops (ICSTW), 2015 IEEE Eighth International Conference on, IEEE, 2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    As technology becomes ubiquitous, new vulnerabilities are being discovered at a rapid rate. Security experts continuously find ways to detect attempts to exploit those vulnerabilities. The outcome is an extremely large and complex rule set used by Intrusion Detection Systems (IDSs) to detect and prevent the vulnerabilities. The rule sets have become so large that it seems infeasible to verify their precision or identify overlapping rules. This work proposes a methodology consisting of a set of tools that will make rule management easier.

  • 15.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    IDS rule management made easy2016Inngår i: Electronics, Computers and Artificial Intelligence (ECAI), 2016 8th International Conference on, IEEE, 2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Signature-based intrusion detection systems (IDSs) are commonly utilized in enterprise networks to detect and possibly block a wide variety of attacks. Their application in industrial control systems (ICSs) is also growing rapidly as modem ICSs increasingly use open standard protocols instead of proprietary. Due to an ever changing threat landscape, the rulesets used by these IDSs have grown large and there is no way to verify their precision or accuracy. Such broad and non-optimized rulesets lead to false positives and an unnecessary burden on the IDS, resulting in possible degradation of the security. This work proposes a methodology consisting of a set of tools to help optimize the IDS rulesets and make rule management easier. The work also provides attack traffic data that is expected to benefit the task of IDS assessment.

  • 16.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Multipath TCP IDS Evasion and Mitigation2015Inngår i: Information Security: 18th International Conference, ISC 2015, Trondheim, Norway, September 9-11, 2015, Proceedings / [ed] Javier Lopez & Chris J. Mitchell, Springer, 2015, Vol. 9290, s. 265-282Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The existing network security infrastructure is not ready for future protocols such as Multipath TCP (MPTCP). The outcome is that middleboxes are configured to block such protocols. This paper studies the security risk that arises if future protocols are used over unaware infrastructures. In particular, the practicality and severity of cross-path fragmentation attacks utilizing MPTCP against the signature-matching capability of the Snort intrusion detection system (IDS) is investigated. Results reveal that the attack is realistic and opens the possibility to evade any signature-based IDS. To mitigate the attack, a solution is also proposed in the form of the MPTCP Linker tool. The work outlines the importance of MPTCP support in future network security middleboxes.

  • 17.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lidén, Anders
    Towards Multipath TCP Aware Security Technologies2016Inngår i: 2016 8th IFIP International Conference onNew Technologies, Mobility and Security (NTMS), New York: IEEE, 2016, s. 1-8Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Multipath TCP (MPTCP) is a proposed extension to TCP that enables a number of performance advantages that have not been offered before. While the protocol specification is close to being finalized, there still remain some unaddressed challenges regarding the deployment and security implications of the protocol. This work attempts to tackle some of these concerns by proposing and implementing MPTCP aware security services and deploying them inside a proof of concept MPTCP proxy. The aim is to enable hosts, even those without native MPTCP support, to securely benefit from the MPTCP performance advantages. Our evaluations show that the security services that are implemented enable proper intrusion detection and prevention to thwart potential attacks as well as threshold rules to prevent denial of service (DoS) attacks.

  • 18.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Lidén, Anders
    A Multipath TCP Proxy2015Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Multipath TCP (MPTCP) is an extension to traditionalTCP that enables a number of performance advantages,which were not offered before. While the protocol specificationis close to being finalized, there still remain some concernsregarding deployability and security. This paper describes theon going work to develop a solution that will facilitate thedeployment of MPTCP. The solution will not only allow non-MPTCP capable end-hosts to benefit from MPTCP performancegains, but also help ease the network security concerns that manymiddleboxes face due to the possibility of data stream beingfragmented across multiple subflows.

  • 19.
    Afzal, Zeeshan
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Rossebø, Judith
    Integrated Operations, ABB AS, Norway.
    Chowdhury, Mohammad
    Talha, Batool
    ABB Corporate Research, ABB AS, Norway.
    A Wireless Intrusion Detection System for 802.11 networks2016Inngår i: PROCEEDINGS OF THE 2016 IEEE INTERNATIONAL CONFERENCE ON WIRELESS COMMUNICATIONS, SIGNAL PROCESSING AND NETWORKING (WISPNET), IEEE, 2016, s. 828-834Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Wireless local area networks (WLANs) deployment is increasing rapidly. At the same time, WLANs have become an attractive target for many potential attackers. In spite of that, the de facto standard used to implement most WLANs (IEEE 802.11) has what appear to be residual vulnerabilities related to identity spoofing. In this paper, a pragmatic study of two common attacks on the standard is conducted. These attacks are then implemented on test beds to learn attack behavior. Finally, novel attack signatures and techniques to detect these attacks are devised and implemented in a proof of concept Wireless Intrusion Detection System (WIDS).

  • 20.
    Agapi, Mesodiakaki
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Zola, Enrica
    UPC BarcelonaTECH, Barcelona Spain.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Joint User Association and Backhaul Routing for Green 5G Mesh Millimeter Wave Backhaul Networks2017Inngår i: Proceedings Of The 20Th Acm International Conference On Modelling, Analysis And Simulation Of Wireless And Mobile Systems, Association for Computing Machinery (ACM), 2017, s. 179-186Konferansepaper (Fagfellevurdert)
    Abstract [en]

    With the advance of fifth generation (5G) networks, network density needs to grow significantly in order to meet the required capacity demands. A massive deployment of small cells may lead to a high cost for providing. ber connectivity to each node. Consequently, many small cells are expected to be connected through wireless links to the umbrella eNodeB, leading to a mesh backhaul topology. This backhaul solution will most probably be composed of high capacity point-to-point links, typically operating in the millimeter wave (mmWave) frequency band due to its massive bandwidth availability. In this paper, we propose a mathematical model that jointly solves the user association and backhaul routing problem in the aforementioned context, aiming at the energy efficiency maximization of the network. Our study considers the energy consumption of both the access and backhaul links, while taking into account the capacity constraints of all the nodes as well as the fulfillment of the service-level agreements (SLAs). Due to the high complexity of the optimal solution, we also propose an energy efficient heuristic algorithm (Joint), which solves the discussed joint problem, while inducing low complexity in the system. We numerically evaluate the algorithm performance by comparing it not only with the optimal solution but also with reference approaches under different traffic load scenarios and backhaul parameters. Our results demonstrate that Joint outperforms the state-of-the-art, while being able to find good solutions, close to optimal, in short time.

  • 21.
    Aguiño, Gonzalo Iglesias
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT.
    Performance of VoIP strategies for hybrid Mobile Ad Hoc Networks2007Independent thesis Advanced level (degree of Magister), 20 poäng / 30 hpOppgave
    Abstract [en]

    Last decade, a lot of research has been done in wireless communication technologies. Mobile

    nodes such personal digital assistants (PDAs), notebooks and cell phones are nowadays used

    in human’s daily life.

    MANETs are networks consisting of two or more mobile nodes equipped with wireless

    communication and networking capabilities, but they don’t have any network centrilized

    infrastructure.

    In last few years, MANETs have been emerged to be an important researched subject in the

    field of wireless networking.

    MANETs are autonomous; however they can communicate with other external networks such

    the internet. They are linked to such external networks by mobile nodes acting as gateways.

    This kind of networks is known as hybrid MANETs.

    Voice over Internet Protocol (VoIP), is a technology that allows you to make voice calls using

    a Internet connection instead of a regular (or analog) phone line.

    The goal of this thesis is evaluate the performance of VoIP strategies for hybrid MANETs.

    Two different aspects are evaluated, the session establishment performance and the voice

    quality.

    Network Simulator 2 is used to run several simulations, two different applications are used to

    run voice simulations (Session Initiation Protocol and Exponential traffic generator). We

    evaluate two different cases for voice traffics, voice calls between two MANET nodes and

    voice calls between MANET nodes and external nodes.

    After running the simulations, there are some performance parameters which will reveal the

    results. The key findings of the simulations are: adding gateways, number of voice traffic

    flows and the number of hops between source and destinations. There are some interesting

    results which reveal for example, that adding gateways is not always beneficial.

    Fulltekst (pdf)
    FULLTEXT01
  • 22. Agustí, Ramón
    et al.
    Fazekas, Péter
    Gómez Barquero, David
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Oliver, Miquel
    Pérez-Romero, Jordi
    Tralli, Velio
    NEWCOM DR7.2: First report on common framework/models and activities in Department 72005Rapport (Fagfellevurdert)
    Abstract [en]

    This deliverable provides a description of the framework identified for the collaborative activities between different partners in the context of NEWCOM department 7 on QoS provision in heterogeneous wireless networks. The considered models, assumptions and expected results are pointed out for each activity. The deliverable also includes a report on the means to achieve the integration between the different partners

  • 23. Agustí, Ramón
    et al.
    Fazekas, Péter
    Lindskog, Stefan
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    Oliver, Miquel
    Pérez-Romero, Jordi
    Studer Ferreira, Lucio
    Tralli, Velio
    NEWCOM DR7.4: Final Report on the activities carried out in Department 72007Rapport (Fagfellevurdert)
    Abstract [en]

    This deliverable constitutes the final report of all the activities that carried out in the framework of the NEWCOM department 7. It contains a description of the main technical achievements for each one of the activities in which the department has been organised togehter with the list of indicators reflecting the degree of integration that has been achieved among the different partners

  • 24.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Finding lower bounds of localization with noisy measurements using genetic algorithms2011Inngår i: Proceedings of the first ACM international symposium on Design and analysis of intelligent vehicular networks and applications (DIVANet '11), Miami, Florida, USA: Association for Computing Machinery (ACM), 2011, s. 47-54Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Vehicular Ad-Hoc Networks (VANETs) are wireless networks with mobile nodes (vehicles) which connect in an ad-hoc manner. Many vehicles use the Global Positioning System (GPS) to provide their locations. However the inaccuracy of GPS devices leads to some vehicles incorrectly assuming they are located at different positions and sometimes on different roads. VANETs can be used to increase the accuracy of each vehicle's computed location by allowing vehicles to share information regarding the measured distances to neighbouring vehicles. This paper looks at finding how much improvement can be made given the erroneous measurements present in the system. An evolutionary algorithm is used to evolve instances of parameters used by the VLOCI2 algorithm, also presented in this paper, to find instances which minimises the inaccuracy in computed locations. Simulation results show a definite improvement in location accuracy and lower bounds on how much improvement is possible is inferred.

  • 25. Ahammed, Farhan
    et al.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Finding Lower Bounds of Localization with Noisy Measurements Using Genetic Algorithms2011Rapport (Fagfellevurdert)
  • 26.
    Ahammed, Farhan
    et al.
    The University of Sydney, Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Using simulated annealing to find lower bounds of localization with noisy measurements2012Inngår i: 2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops & PhD Forum (IPDPSW), IEEE conference proceedings, 2012, s. 601-608Konferansepaper (Fagfellevurdert)
  • 27.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    NICTA Australia Australian Technology Park.
    LICA: Improving Localization Given Noisy Data In GPS-Equipped VANETs Using Trilateration With Cluster Analysis2011Rapport (Fagfellevurdert)
  • 28.
    Ahammed, Farhan
    et al.
    University of Sydney.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    NICTA.
    VLOCI: Using Distance Measurements to Improve the Accuracy of Location Coordinates in GPS-Equipped VANETs2012Inngår i: Mobile and Ubiquitous Systems: 7th International ICST Conference, MobiQuitous 2010, Sydney, Australia, December 6-9, 2010, Revised Selected Papers / [ed] Patrick Sénac, Max Ott, Aruna Seneviratne, Springer Berlin/Heidelberg, 2012, Vol. 73, s. 149-161Konferansepaper (Fagfellevurdert)
  • 29.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    NICTA Australia Australian Technology Park.
    VLOCI2: An Iterative Method To Improve Location Coordinates In GPS-Equipped VANETs in Multiple Lanes2011Rapport (Fagfellevurdert)
  • 30.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    Australian Technology Park, Australia.
    VLOCI2: An Iterative Method To Improve Location Coordinates In GPS-Equipped VANETs in Multiple Lanes2011Rapport (Fagfellevurdert)
  • 31.
    Ahl, Elin
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Nordberg, Nina
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013).
    Planning a digital transformation for a company with a process layout: A study conducted at voestalpine Precision Strip AB2018Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Digitalization is an upcoming trend that divides the manufacturing industry of today. As an increasing number of companies chose to implement digitalization as a business strategy, some companies still struggle with implementing digitalization into their businesses.

    Previous research has developed digital transformation models, but has been admitted as too generic. This thesis used the most comprehensive transformation model as base and aimed to make it practically implementable for a manufacturing company with a process layout. To enable this, a case study was conducted on a steel-processing company with this layout design. This thesis had an inductive approach, where primary data were collected from one selected company through a pilot study and semi structured interviews, and secondary data were collected through a literature review.

    During the study, it was discovered that a company can benefit from using a customized guidance of how to implement digitalization, to optimally use digital opportunities. This thesis contributed with additional steps and extensions of the previous transformation model. The contribution consisted of the involvement of competency, creation of definition, identified digitalization trends relating to a SWOT analysis, additional phenomenon to take into consideration when analyzing future scenarios, additional questions to consider when analyzing impacted areas, creation of a digital business strategy, a comparison of impacted areas with previous projects, additional identified actions to fill the gap between current state and goals, and five identified criteria’s on how to prioritize these actions. This study extends current research with details and depth regarding a digital transformation model, and hence make it more practical. For future research, a case study testing the potential of the transformation model on a similar company should be conducted, and thereby improve the model further.

    Fulltekst (pdf)
    fulltext
  • 32.
    Ahlberg, Lina
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Handelshögskolan (from 2013).
    Smarta glasögons användbarhet: Hur användarnas datorvana påverkar användbarheten av smarta glasögon2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Smarta glasögon är interaktiva glasögon som har en inbyggd dator och tillåter användaren att se en bildskärm samtidigt som den materiella omgivningen kan ses. Studiens syfte är att undersöka hur användarens datorvana påverkar den upplevda användbarheten av smarta glasögon. Genomförandet av undersökningen har bestått av att 34 respondenter genomfört ett användartest följt av en strukturerad intervju. Intervjuerna har sedan kategoriserats beroende av datorvana och respondenternas upplevelser, vilket har legat till grund för analysen. För att styrka analysen har en litteraturstudie genomförts av tidigare teori inom ämnena skillnader mellan individer, användbarhet och smarta glasögon. Studiens slutsatser visar på att det inte finns några tydliga skillnader i användarnas upplevelser till följd av den tidigare datorvanan. De skillnader som ändå identifierades är att det finns indikationer på att upplevelsen av svårigheter och effektivitet till viss del påverkats av datorvanan.

    Fulltekst (pdf)
    fulltext
  • 33.
    Ahmad, Muhammad Ovais
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Antecedents To Achieve Kanban Optimum Benefits In Software Companies2019Inngår i: 14th International Conference on Software Engineering Advances, International Academy, Research and Industry Association (IARIA), 2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In 2004, Kanban successfully entered the Agile and Lean realm. Since then, software companies have been increasingly using it in software development teams. The goal of this study is to perform an empirical investigation on antecedents considered as important for achieving optimum benefits of Kanban use and to discuss the practical implications of the findings. We conducted an online survey with software professionals from the Lean Software Development LinkedIn community to investigate the importance of antecedents of using Kanban for achieving optimum benefits. Our study reveals that subjective norm, organizational support, ease of use, Kanban use experience and training are the antecedents for achieving expected benefits of Kanban. The potential benefits of Kanban use can only be realized when the key antecedents are not only identified, but also infused across an organization. When managing the transition to or using Kanban, practitioners need to adapt their strategies on the extent of various antecedents, a few identified in this study.

  • 34.
    Ahmad, Muhammad Ovais
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Preliminary Citation and Topic Analysis of International Conference on Agile Software Development Papers (2002-2018)2019Inngår i: Annals of Computer Science and Information Systems, ISSN 1545-827X, E-ISSN 2300-5963, Vol. 18, s. 803-812Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This study utilizes citation analysis and automated topic analysis of papers published in International Conference on Agile Software Development (XP) from 2002 to 2018. We collected data from Scopus database, finding 789 XP papers. We performed topic and trend analysis with R/RStudio utilizing the text mining approach, and used MS Excel for the quantitative analysis of the data. The results show that the first five years of XP conference cover nearly 40% of papers published until now and almost 62% of the XP papers are cited at least once. Mining of XP conference paper titles and abstracts result in these hot research topics: “Coordination”, “Technical Debt”, “Teamwork”, “Startups” and “Agile Practices”, thus strongly focusing on practical issues. The results also highlight the most influential researchers and institutions. The approach applied in this study can be extended to other software engineering venues and applied to large-scale studies.

  • 35.
    Ahmad, Muhammad Ovais
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    SOFTWARE FACTORY PROJECT FOR ENHANCEMENT OF STUDENT EXPERIENTIAL LEARNING2019Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Providing opportunities for students to work on real-world software development projects for real customers is critical to prepare students for the IT industry. Such projects help students to understand what they will face in the industry and experience real customer interaction and challenges in collaborative work. To provide this opportunity in an academic environment and enhance the learning and multicultural teamwork experience, the University of Oulu, Finland offers the software factory (SWF) project. This paper presents the design of the SWF course and the learning environment and assessment techniques, and it discusses the importance of reflective learning diaries and serious games. Additionally, this paper examines factors in the SWF learning environment that affect student learning in the SWF course. Survey data were collected from the last six years of SWF projects. The results show that students consider the SWF to be a good collaborative learning environment that helps them achieve academic triumphs and enhances various professional skills. The learning diaries are effective for increasing students’ learning experiences as well as providing an opportunity for teaching staff to monitor students’ progress and offer better facilitation. These results are helpful for academic institutions and industry when developing such a learning environment.

  • 36.
    Ahmad, Muhammad Ovais
    et al.
    University of Oulu, Finland.
    Liukkunen, Kari
    University of Oulu, Finland .
    Markkula, Jouni
    University of Oulu, Finland.
    Student perceptions and attitudes towards the software factory as a learning environment2014Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Industry needs graduates from universities having knowledge and skills to tackle the practical issues of real life software development. To facilitate software engineering students and fulfill industry need, the Department of Information Processing Science, University of Oulu, Finland, built a Software Factory laboratory (SWF) in 2012 based on Lean concept. This study examines factors in the SWF learning environment that affect learning of a SWF course by the students. It employs amended Computer laboratory Environment Inventory (CLEI) and Attitude towards Computers and Computing Courses Questionnaire instrument (ACCC) with two additional constructs: 1) Kanban board 2) Collaborative learning. The general findings indicate that SWF learning environment, collaborative learning and Kanban board play important role in software engineering students learning, academic achievements and professional skills gaining. The findings are helpful to develop a better understanding about learning environments. The information gathered in this study can also be used to improve the software engineering learning environment.

  • 37.
    Ahmad, Muhammad Ovais
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Raulamo-Jurvanen, P
    Scientific Collaboration, Citation and Topic Analysis of International Conference on Agile Software Development Papers2019Inngår i: Advances in Agile and User-Centred Software Engineering, Springer, 2019, s. 108-132Kapittel i bok, del av antologi (Fagfellevurdert)
    Abstract [en]

    The International Conference on Agile Software Development (XP) was established almost sixteen years ago. Based on data from Scopus database, a total of 789 papers have been published in between years of 2002 and 2018. We employed bibliometrics analysis and topic modeling with R/RStudio to analyze these published papers from various dimensions, including the most active authors, collaboration of authorship, most cited papers, used keywords and trends of probable topics from the titles and abstracts of those papers. The results show that the first five years of XP conference cover nearly 40% of the papers published until now and almost 62% of the XP papers have been cited at least once. Mining of XP conference paper titles and abstracts result in these hot research topics: “Coordination”, “Technical Debt”, “Teamwork”, “Startups” and “Agile Practices”, thus strongly focusing on practical issues and problems faced by the practitioners in the industry. The results highlight the most influential researchers and institutions, and the collaboration between the authors in the conference papers. The approach applied in this study can be extended to other software engineering venues and can be applied to large-scale studies.

  • 38.
    Ahmed, Bestoun S.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    An Automated Testing Framework For Smart TVapps Based on Model Separation2020Inngår i: IEEE International Conference on Software Testing, Verification and Validation Workshops (ICSTW), IEEE Computer Society, 2020, s. 62-73Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Smart TV application (app) is a new technological software app that can deal with smart TV devices to add more functionality and features. Despite its importance nowadays, far too little attention has been paid to present a systematic approach to test this kind of app so far. In this paper, we present a systematic model-based testing approach for smart TV app. We used our new notion of model separation to use sub-models based on the user preference instead of the exhaustive testing to generate the test cases. Based on the constructed model, we generated a set of test cases to assess the selected paths to the chosen destination in the app. We also defined new mutation operators for smart TV app to assess our testing approach. The evaluation results showed that our approach can generate more comprehensive models of smart TV apps with less time as compared to manual exploratory testing. The results also showed that our approach can generate effective test cases in term of fault detection.

  • 39.
    Ahmed, Bestoun S.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Avocado: Open-Source Flexible ConstrainedInteraction Testing for Practical Application2020Inngår i: IEEE International Conference on Software Testing, Verification and Validation Workshops (ICSTW), IEEE Computer Society, 2020, s. 185-190Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents the outcome of a research collaboration between academia and industry to implement and utilize the capabilities of constrained interaction testing for an open-source tool for industrial-scale application. The project helps promote flexibility in generating constrained interaction test suites, executing them, and setting up a test oracle to report them–all within the same tool called Avocado. Avocado employs a constraint solver with computational algorithms to generate constrained interaction test suites. The environment of the application under test can be set up to execute the generated test suite with minimum effort. A test oracle can be set up by the tool to report the status and the results of the executed test cases. Avocado represents a comprehensive and flexible solution for conducting combinatorial interaction testing (CIT) and constrained CIT on an industrial application. In this paper, we present the structure of the tool and our method of implementing the algorithms in detail.

  • 40.
    Ahmed, Bestoun S.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Open-source Defect Injection Benchmark Testbedfor the Evaluation of Testing2020Inngår i: IEEE 13th International Conference on Software Testing, Validation and Verification (ICST), IEEE Computer Society, 2020, s. 442-447Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A natural method to evaluate the effectiveness of a testing technique is to measure the defect detection rate when applying the created test cases. Here, real or artificial software defects can be injected into the source code of software. For a more extensive evaluation, injection of artificial defects is usually needed and can be performed via mutation testing using code mutation operators. However, to simulate complex defects arising from a misunderstanding of design specifications, mutation testing might reach its limit in some cases. In this paper, we present an open-source benchmark testbed application that employs a complement method of artificial defect injection. The application is compiled after artificial defects are injected into its source code from predefined building blocks. The majority of the functions and user interface elements are covered by creating front-end-based automated test cases that can be used in experiments.

  • 41.
    Ahmed, Bestoun S.
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Bures, Miroslav
    Czech Technical University, Czech Republic.
    EvoCreeper: Automated Black-Box Model Generation for Smart TV Applications2019Inngår i: IEEE transactions on consumer electronics, ISSN 0098-3063, E-ISSN 1558-4127, Vol. 65, nr 2, s. 160-169Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Abstract—Smart TVs are coming to dominate the televisionmarket. This accompanied by an increase in the use of the smartTV applications (apps). Due to the increasing demand, developersneed modeling techniques to analyze these apps and assess theircomprehensiveness, completeness, and quality. In this paper, wepresent an automated strategy for generating models of smartTV apps based on a black-box reverse engineering. The strategycan be used to cumulatively construct a model for a given app byexploring the user interface in a manner consistent with the use ofa remote control device and extracting the runtime information.The strategy is based on capturing the states of the user interfaceto create a model during runtime without any knowledge ofthe internal structure of the app. We have implemented ourstrategy in a tool called EvoCreeper. The evaluation results showthat our strategy can automatically generate unique states anda comprehensive model that represents the real user interactionswith an app using a remote control device. The models thusgenerated can be used to assess the quality and completeness ofsmart TV apps in various contexts, such as the control of otherconsumer electronics in smart houses.

    Fulltekst (pdf)
    fulltext
  • 42.
    Ahmed, Bestoun S.
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Bures, Miroslav
    Czech Technical University in Prague, Prague.
    Frajtak, Karel
    Czech Technical University in Prague, Prague.
    Cerny, Tomas
    Baylor University, Waco.
    Aspects of Quality in Internet of Things (IoT) Solutions: A Systematic Mapping Study2019Inngår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 13758-13780Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Internet of Things (IoT) is an emerging technology that has the promising power to change our future. Due to the market pressure, IoT systems may be released without sufficient testing. However, it is no longer acceptable to release IoT systems to the market without assuring the quality. As in the case of new technologies, the quality assurance process is a challenging task. This paper shows the results of the first comprehensive and systematic mapping study to structure and categories the research evidence in the literature starting in 2009 when the early publication of IoT papers for IoT quality assurance appeared. The conducted research is based on the most recent guidelines on how to perform systematic mapping studies. A set of research questions is defined carefully regarding the quality aspects of the IoT. Based on these questions, a large number of evidence and research papers is considered in the study (478 papers). We have extracted and analyzed different levels of information from those considered papers. Also, we have classified the topics addressed in those papers into categories based on the quality aspects. The study results carry out different areas that require more work and investigation in the context of IoT quality assurance. The results of the study can help in a further understanding of the research gaps. Moreover, the results show a roadmap for future research directions.

  • 43.
    Ahmed, Bestoun S.
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Eduard, Enoiu
    Mälardalen University, Västerås, Sweden.
    Wasif, Afzal
    Mälardalen University, Västerås, Sweden.
    Kamal Z, Zamli
    University Malaysia Pahang, Pekan, Malaysia.
    An evaluation of Monte Carlo-based hyper-heuristic for interaction testing of industrial embedded software applications2020Inngår i: Soft Computing - A Fusion of Foundations, Methodologies and Applications, ISSN 1432-7643, E-ISSN 1433-7479Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Hyper-heuristic is a new methodology for the adaptive hybridization of meta-heuristic algorithms to derive a general algorithm for solving optimization problems. This work focuses on the selection type of hyper-heuristic, called the exponential Monte Carlo with counter (EMCQ). Current implementations rely on the memory-less selection that can be counterproductive as the selected search operator may not (historically) be the best performing operator for the current search instance. Addressing this issue, we propose to integrate the memory into EMCQ for combinatorial t-wise test suite generation using reinforcement learning based on the Q-learning mechanism, called Q-EMCQ. The limited application of combinatorial test generation on industrial programs can impact the use of such techniques as Q-EMCQ. Thus, there is a need to evaluate this kind of approach against relevant industrial software, with a purpose to show the degree of interaction required to cover the code as well as finding faults. We applied Q-EMCQ on 37 real-world industrial programs written in Function Block Diagram (FBD) language, which is used for developing a train control management system at Bombardier Transportation Sweden AB. The results show that Q-EMCQ is an efficient technique for test case generation. Addition- ally, unlike the t-wise test suite generation, which deals with the minimization problem, we have also subjected Q-EMCQ to a maximization problem involving the general module clustering to demonstrate the effectiveness of our approach. The results show the Q-EMCQ is also capable of outperforming the original EMCQ as well as several recent meta/hyper-heuristic including modified choice function, Tabu high-level hyper-heuristic, teaching learning-based optimization, sine cosine algorithm, and symbiotic optimization search in clustering quality within comparable execution time.

    Fulltekst (pdf)
    fulltext
  • 44.
    Ahmed, Bestoun S.
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Czech Technical University, Prague, Czech Republic.
    Gargantini, Angelo
    University of Bergamo, Italy.
    Zamli, Kamal Z.
    University Malaysia Pahang, Pahang, Malaysia.
    Yilmaz, Cemal
    Sabanci University, Istanbul, Turkey.
    Bures, Miroslav
    Czech Technical University, Prague, Czech Republic.
    Szeles, Marek
    Czech Technical University, Prague, Czech Republic.
    Code-Aware Combinatorial Interaction Testing2019Inngår i: IET Software, ISSN 1751-8806, E-ISSN 1751-8814, Vol. 13, nr 6, s. 600-609Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Combinatorial interaction testing (CIT) is a useful testing technique to address the interaction of input parameters in software systems. In many applications, the technique has been used as a systematic sampling technique to sample the enormous possibilities of test cases. In the last decade, most of the research activities focused on the generation of CIT test suites as it is a computationally complex problem. Although promising, less effort has been paid for the application of CIT. In general, to apply the CIT, practitioners must identify the input parameters for the Software-under-test (SUT), feed these parameters to the CIT tool to generate the test suite, and then run those tests on the application with some pass and fail criteria for verification. Using this approach, CIT is used as a black-box testing technique without knowing the effect of the internal code. Although useful, practically, not all the parameters having the same impact on the SUT. This paper introduces a different approach to use the CIT as a gray-box testing technique by considering the internal code structure of the SUT to know the impact of each input parameter and thus use this impact in the test generation stage. We applied our approach to five reliable case studies. The results showed that this approach would help to detect new faults as compared to the equal impact parameter approach.

    Fulltekst (pdf)
    fulltext
  • 45.
    Ahmed, Bestoun S.
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Pahim, Amador
    Red Hat Czech s.r.o., Brno, Czech Republic .
    Rosa Junior, Cleber R
    Red Hat, Inc., Westford, USA .
    Kuhn, D. Richard
    Natl Inst of Standards and Technology, Gaithersburg, MD, USA .
    Bures, Miroslav
    Dept of Computer Science, Czech Technical Univ, Prague, Czech Republic .
    Towards an Automated Unified Framework to Run Applications for Combinatorial Interaction Testing2019Inngår i: EASE '19 Proceedings of the Evaluation and Assessment on Software Engineering, NY, USA: Association for Computing Machinery (ACM), 2019, s. 252-258Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Combinatorial interaction testing (CIT) is a well-known technique,but the industrial experience is needed to determine its effectivenessin different application domains. We present a case study introducinga unified framework for generating, executing and verifyingCIT test suites, based on the open-source Avocado test framework.In addition, we present a new industrial case study to demonstratethe effectiveness of the framework. This evaluation showed thatthe new framework can generate, execute, and verify effective combinatorialinteraction test suites for detecting configuration failures(invalid configurations) in a virtualization system.

  • 46.
    Airola, Rasmus
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Hager, Kristoffer
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Image Classification, Deep Learning and Convolutional Neural Networks: A Comparative Study of Machine Learning Frameworks2017Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    The use of machine learning and specifically neural networks is a growing trend in software development, and has grown immensely in the last couple of years in the light of an increasing need to handle big data and large information flows. Machine learning has a broad area of application, such as human-computer interaction, predicting stock prices, real-time translation, and self driving vehicles. Large companies such as Microsoft and Google have already implemented machine learning in some of their commercial products such as their search engines, and their intelligent personal assistants Cortana and Google Assistant.

    The main goal of this project was to evaluate the two deep learning frameworks Google TensorFlow and Microsoft CNTK, primarily based on their performance in the training time of neural networks. We chose to use the third-party API Keras instead of TensorFlow's own API when working with TensorFlow. CNTK was found to perform better in regards of training time compared to TensorFlow with Keras as frontend. Even though CNTK performed better on the benchmarking tests, we found Keras with TensorFlow as backend to be much easier and more intuitive to work with. In addition, CNTKs underlying implementation of the machine learning algorithms and functions differ from that of the literature and of other frameworks. Therefore, if we had to choose a framework to continue working in, we would choose Keras with TensorFlow as backend, even though the performance is less compared to CNTK.

    Fulltekst (pdf)
    fulltext
    Fulltekst (pdf)
    Arkivfil
  • 47.
    Aitenbichler, Erwin
    et al.
    Technische Universität Darmstadt, Germany.
    Behring, Alexander
    Technische Universität Darmstadt, Germany.
    Bradler, Dirk
    Technische Universität Darmstadt, Germany.
    Hartmann, Melanie
    Technische Universität Darmstadt, Germany.
    Martucci, Leonardo
    Technische Universität Darmstadt, Germany.
    Mühlhäuser, Max
    Technische Universität Darmstadt, Germany.
    Ries, Sebastian
    Technische Universität Darmstadt, Germany.
    Schnelle-Walka, Dirk
    Technische Universität Darmstadt, Germany.
    Schreiber, Daniel
    Technische Universität Darmstadt, Germany.
    Steimle, Jürgen
    Technische Universität Darmstadt, Germany.
    Strufe, Thorsten
    Technische Universität Darmstadt, Germany.
    Shaping the Future Internet2009Inngår i: Proceedings of the 3rd International CompanionAble Workshop IoPTS, Brussels, 2. December 2009., The CompanionAble , 2009Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The Internet of Things (IoT) and the Internet of Services (IoS) are two well-knownexemplars of the emerging ‘Internet variants’. These variants will be tightlyinterwoven yet specific with respect to the supporting technologies needed. Thepresent paper discusses the five variants identified as essential by the authors: IoT,IoS, Internet-of-Humans, Internet-of-Crowds, and Internet-of-Clouds. For eachvariant, a non-comprehensive set of research challenges is cited and related to thestate of the art and to ongoing projects of the lab.

    Fulltekst (pdf)
    fulltext
  • 48.
    Akil, Mahdi
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Mancini, L. V.
    Universita di Roma Sapienza, Rome, Italy.
    Venturi, D.
    Universita di Roma Sapienza, Rome, Italy.
    Multi-covert channel attack in the cloud2019Inngår i: 2019 6th International Conference on Software Defined Systems, SDS 2019, Institute of Electrical and Electronics Engineers Inc. , 2019, s. 160-165Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Frequently, it is believed that the adoption of encryption is adequate to ensure the safety of the message. However, encryption only restricts unapproved individuals from decoding the message. Whereas in many circumstances, the mere presence of communication or variations in communication patterns, such as an increase in message rate, is sufficient to raise doubt and initiate alerts. One of the best ways to bypass that is by using covert channels. In this paper, we create innovative protocols that use multiple covert channels working in parallel to exfiltrate data from a remote-controlled machine to our server. The provided protocols guarantee the completeness and unforgeability of the exfiltrated data. We analyze the difference in performance between the created protocols and provide mathematical equations to evaluate them.

  • 49.
    Al-abuhalje, Afrah
    et al.
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT.
    Al-abuhalje, Sanaa
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT.
    Översikt och tillämpning av XML2007Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Sammanfattning

    Allt eftersom kraven ökat på mer avancerade applikationer över Internet har det förekommit kritik mot att HTML inte räcker till, vilket är en av anledningarna till att ett nytt märkningsspråk som heter XML växt fram. I det här arbetet redogör vi för, alltifrån grunderna i XML till mer avancerade delar som DTD, XML-schema och XSLT.

    XML kombinerar HTML:s enkelhet med SGML:s möjligheter. En av XML:s främsta styrkor är att det kan användas för att lagra all typ av data, utan att man behöver ta någon hänsyn till hur den senare ska presenteras. Innehåll och presentation är helt separerade. En annan viktig egenskap är att XML-dokument lagras som vanliga textfiler, vilket innebär att XML är system- och plattformsoberoende.

    I denna uppsats utgår vi från två mål, dels att tillämpa XML för att skapa ett lämpligt lagringsformat för konfigurationsdata till en nätverksemulator, och dels att redogöra för XML. För att emulera förhållanden som finns i ett riktigt nätverk kan t ex bitfel,

    paketförluster, bandbreddsbegränsning och fördröjning emuleras. Inställningar av önskad frekvens av paketförluster, bitfel o s v är exempel på konfigurationsdata. Då vi redogör för XML återkopplar vi till, och beskriver tillämpningen stegvis. På så sätt får läsaren en god inblick i hur XML fungerar.

    Fulltekst (pdf)
    FULLTEXT01
  • 50.
    Ala-Häivälä, Anders
    Karlstads universitet, Fakulteten för samhälls- och livsvetenskaper.
    Batch-digitalisering och GIS-anpassning av analoga enkätdata2007Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [sv]

    I denna rapport beskrivs arbetet med att tillvarata och anpassa data från en enkätundersökning till digital hantering i GIS. Undersökningen är en besöksstudie utförd av Karlstads kommun och Skogsstyrelsen för att kartlägga människors rörelsemönster i I2-Skogen, ett gammalt militärt övningsfält som numera används som rekreationsområde. Enkäten består av ett antal frågor om exempelvis typ av aktivitet, ålder och åsikter om området, samt en karta på vilken besökaren ritat in var i området han eller hon rört sig. Utgångsmaterialet för arbetet har varit en databas innehållande enkätsvaren, samt originalkartorna med den ritade informationen. Arbetet omfattar dels att undersöka om kartinformationen kan digitaliseras automatiskt genom scanning och vektorisering i batch, och dels att normalisera och strukturera databasen med enkätsvaren.

    En metod för digitalisering har utarbetats och testats på ett urval av kartorna. Metoden består av ett antal steg och innefattar bl a bearbetning av kartorna i bildbehandlingsprogram samt klassning och vektorisering i GIS-programvara. Eftersom batchfunktioner saknas i GIS-programvaran har makron skapats genom programmering i VBA. Metoden har visat sig fungera bra på urvalet och slutsatsen blir att det är fullt möjligt att digitalisera de ritade linjerna med automatik. Dock finns vissa brister avseende noggrannhet och användbarhet. Dessutom är urvalet relativt litet och viss justering av inställningarna för klassning och vektorisering kan vara nödvändig vid tillämpning på större delar av materialet.

    Databasen har normaliserats så långt som ansetts rimligt med tanke på prestanda och användbarhet. För att tillförlitliga sökningar ska kunna utföras har flera attribut tolkats och modifierats genom indelning i kategorier och intervall.

    Arbetet har resulterat i en geodatabas innehållande samtliga enkätsvar samt det utvalda materialet från digitaliseringstestet. För att visa hur databasen kan användas har två enkla analysexempel tagits fram.

    Fulltekst (pdf)
    FULLTEXT01
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