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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 filter2020Ingår i: European transactions on telecommunications, ISSN 1124-318X, E-ISSN 2161-3915, artikel-id e3734Artikel i tidskrift (Refereegranskat)
    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.
    Abbas, Muhammad Tahir
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Muhammad, Afaq
    Sarhad Univ Sci & Informat Technol, Dept Comp Sci & IT, Peshawar, Pakistan.
    Song, Wang-Cheol
    Jeju Natl Univ, Dept Comp Engn, Jeju, South Korea.
    Road-Aware Estimation Model for Path Duration in Internet of Vehicles (IoV)2019Ingår i: Wireless personal communications, ISSN 0929-6212, E-ISSN 1572-834X, Vol. 109, nr 2, s. 715-738Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    In Internet of Vehicles (IoV), numerous routing metrics have been used to assess the performance of routing protocols such as, packet delivery ratio, throughput, end-to-end delay and path duration. Path duration is an influential design parameter, among these routing metrics, that determines the performance of vehicular networks. For instance, in highly dynamic scenarios, it can be used to predict link life time in on-demand routing protocols. In this paper, we propose an infrastructure-assisted hybrid road-aware routing protocol which is capable of enhanced vehicle-to-vehicle and vehicle-to-infrastructure communication. A remarkable aspect of the proposed protocol is that it establishes a link between path duration and fundamental design parameters like vehicular velocity, density, hop count and transmission range. Although, a lot of research has been previously performed, a well defined analytical model for IoV is not available in the literature. Precisely, a relation between path duration and vehicular velocity has not been validated in the previous studies. Experimental results show that the increased packet delivery ratio with reduced end-to-end delay can be achieved by the prediction of path duration. Proposed model for path duration is validated by getting experimental results from network simulator 3 (NS3) and analytical results from MATLAB. In addition, SUMO simulator was used to generate real time traffic on the roads of Gangnam district, South Korea.

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  • 3.
    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 packet2010Ingår i: Proceedings of The Sixth Advanced International Conference on Telecommunications - AICT 2010, IEEE conference proceedings, 2010, s. 316-322Konferensbidrag (Refereegranskat)
    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.

  • 4.
    Abdu, Mohammed
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Integrated Source Code and Architectural Quality Analysis Using Neo4j Graph Database2024Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [en]

    In the realm of software engineering, understanding the architecture and measuringthe quality of a source code is essential for maintaining and enhancing softwaresystems. However, many existing tools fall short in evaluating architectural aspects,such as detecting architectural erosion or addressing architecture-related metrics andconstraints tailored to the unique context of their systems or organisations. Thisdeficiency restricts proactive architecture governance and hinders the mitigation ofarchitecture-related risks, creating a critical gap in the analysis of software sourcecode.

    This thesis presents a novel approach to tackle these challenges. It proposes a graphdatabase as a data structure for analysing the source code and architecture quality andcalculating various architectural metrics of interest. The tool developed in this thesisrepresents the source code structural elements and their relationships in the graphdatabase, enabling an intuitive analysis of the source code architecture.

    The tool also integrates different code quality metrics parsed from Visual Studiocode metrics results, mapped to their correspondent nodes to assess the source codeoverall quality and identify potential areas of improvement. This empowers softwareengineers and developers to make informed decisions regarding refactoring, codeoptimisation, and architectural enhancements.

    Furthermore, the tool allows users to define the intended architecture in terms ofmodules to reveal any Architecture erosion (AEr). It also provides the flexibility toestablish custom constraints and metrics through tailored queries, accommodating theunique requirements of their system and company.

    A case study conducted on a real-world software project validates the effectivenessand usefulness of the proposed approach. The case study demonstrates how the toolanalysis reveals valuable insights into the source code health and identifies patternsthat can impact maintainability and scalability. The results of this research showcasethe potential of our tool as a powerful instrument for analysing the code qualityand architecture of source code, fostering more resilient and sustainable softwaresystems.

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    Integrated Source Code and Architectural Quality Analysis Using Neo4j Graph Database
  • 5.
    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 detection2019Ingår i: Proceedings - International Conference on Computer Communications and Networks, ICCCN, IEEE, 2019Konferensbidrag (Refereegranskat)
    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.

  • 6.
    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 Applications2018Konferensbidrag (Refereegranskat)
  • 7.
    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 Performance2018Ingår i: 2018 NETWORK TRAFFIC MEASUREMENT AND ANALYSIS CONFERENCE (TMA), IEEE, 2018Konferensbidrag (Refereegranskat)
    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.

  • 8. 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 networks2013Ingår i: Journal of Quality Measurement and Analysis, ISSN 1823-5670, Vol. 9, nr 2, s. 11-26Artikel i tidskrift (Refereegranskat)
  • 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 (Refereegranskat)
  • 10.
    Adolfsson, David
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Channel Estimation Optimization in 5G New Radio using Convolutional Neural Networks2023Självständigt arbete på avancerad nivå (masterexamen), 20 poäng / 30 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Kanalestimering är en process i trådlösa kommunikationssystem som handlar om att analysera och förstå det trådlösa mediumets egenskaper. Genom effektiv kanalestimering kan dataöverföringen optimeras genom att anpassa signalen efter den trådlösa kanalen. Detta arbete utforskar användningen av ett konvolutionellt neuralt nätverk (CNN) för kanalestimering i Tietoevrys 5G-datalänkslagersimulator (5G-LLS). Målen är att (1) skapa ett Python-ramverk för kanalestimeringsexperiment samt att (2) utvärdera CNN:s prestanda jämfört med konventionella algoritmerna minsta kvadratmetoden (LS), minimalt medelkvadratsfel (MMSE) och linjärt minimalt medelkvadratsfel (LMMSE). Två olika kanalmodellsituationer undersöks i detta arbete.

    Resultaten visar att CNN överträffar LMMSE, LS och MMSE i form av medelkvadratisk fel (MSE) för båda kanalmodellerna, med LMMSE på andra plats. CNN:n lyckades minska MSE:n med 85\% jämfört med LMMSE för den korrelerade kanalen och med 78\% för den snabbt dämpande kanalen. Vad gäller systemnivåprestanda, mätt med hjälp av bitfelsfrekvens (BER), lyckades CNN endast överträffa LS och MMSE. CNN och LMMSE gav liknande resultat. Detta beror på att LMMSE:s MSE fortfarande var tillräckligt låg för att korrekt demodulera symbolerna för QPSK-modulationsschemat.

    Resultatet från detta examensarbete möjliggör för Tietoevry att implementera fler maskininlärningsalgoritmer och vidareutveckla kanalestimering inom 5G-telekommunikation och trådlösa kommunikationsnätverk genom experiment i 5G-LLS. Med tanke på att CNN inte överträffade samtliga kanalestimeringstekniker bör framtida studier testa ett bredare utbud av kanalmodeller och överväga mer komplexa moduleringsscheman. Framtida arbeten bör även utforska fler och mer avancerade maskininlärningsalgoritmer än CNN.

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    ChannelEstimationIn5GNR-davidadolfsson
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    Arkivfil
  • 11.
    Afifi, Haitham
    et al.
    Hasso Platter Institute, Germany.
    Ramaswamy, Arunselvan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Karl, Holger
    Hasso Platter Institute, Germany.
    Reinforcement learning for autonomous vehicle movements in wireless multimedia applications2023Ingår i: Pervasive and Mobile Computing, ISSN 1574-1192, E-ISSN 1873-1589, Vol. 92, artikel-id 101799Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    We develop a Deep Reinforcement Learning (DeepRL)-based, multi-agent algorithm to efficiently control autonomous vehicles that are typically used within the context of Wireless Sensor Networks (WSNs), in order to boost application performance. As an application example, we consider wireless acoustic sensor networks where a group of speakers move inside a room. In a traditional setup, microphones cannot move autonomously and are, e.g., located at fixed positions. We claim that autonomously moving microphones improve the application performance. To control these movements, we compare simple greedy heuristics against a DeepRL solution and show that the latter achieves best application performance. As the range of audio applications is broad and each has its own (subjective) per-formance metric, we replace those application metrics by two immediately observable ones: First, quality of information (QoI), which is used to measure the quality of sensed data (e.g., audio signal strength). Second, quality of service (QoS), which is used to measure the network's performance when forwarding data (e.g., delay). In this context, we propose two multi-agent solutions (where one agent controls one microphone) and show that they perform similarly to a single-agent solution (where one agent controls all microphones and has a global knowledge). Moreover, we show via simulations and theoretical analysis how other parameters such as the number of microphones and their speed impacts performance.

  • 12.
    Afzal, Samira
    et al.
    Alpen-Adria-Universität Klagenfurt, Austria.
    Ferlin-Reiter, SimoneKarlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Red Hat Ab.Hoßfeld, TobiasUniversity of Würzburg, Germany.Schatz, RaimundAustrian Institute of Technology, Austria.Timmerer, ChristianAlpen-Adria-Universität Klagenfurt, Austria.
    GMSys '23: Proceedings of the First International Workshop on Green Multimedia Systems2023Proceedings (redaktörskap) (Refereegranskat)
  • 13.
    Afzal, Zeeshan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Towards Secure Multipath TCP Communication2017Licentiatavhandling, sammanläggning (Övrigt vetenskapligt)
    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.

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    omslag
  • 14.
    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) (Övrigt vetenskapligt)
  • 15.
    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 Applications2018Ingår i: Proceedings of NTMS 2018 Conference and Workshop, New York: IEEE, 2018, s. 1-5Konferensbidrag (Refereegranskat)
    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.

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    fulltext
  • 16.
    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).
    Using Partial Signatures in Intrusion Detection for Multipath TCP2019Ingår i: Secure IT-systems: 24th Nordic Conference, NordSec 2019, Aalborg, Denmark, November 18–20, 2019, Proceedings / [ed] Aslan Askarov, René Rydhof Hansen, Willard Rafnsson, Cham, Switzerland: Springer, 2019, s. 71-86Konferensbidrag (Refereegranskat)
    Abstract [en]

    Traditional security mechanisms such as signature basedintrusion detection systems (IDSs) attempt to find a perfect match of aset of signatures in network traffic. Such IDSs depend on the availabilityof a complete application data stream. With emerging protocols such asMultipath TCP (MPTCP), this precondition cannot be ensured, result-ing in false negatives and IDS evasion. On the other hand, if approximatesignature matching is used instead in an IDS, a potentially high numberof false positives make the detection impractical. In this paper, we showthat, by using a specially tailored partial signature matcher and knowl-edge about MPTCP semantics, the Snort3 IDS can be empowered withpartial signature detection. Additionally, we uncover the type of Snort3rules suitable for the task of partial matching. Experimental results withthese rules show a low false positive rate for benign traffic and highdetection coverage for attack traffic.

  • 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).
    Automated Testing of IDS Rules2015Ingår i: Software Testing, Verification and Validation Workshops (ICSTW), 2015 IEEE Eighth International Conference on, IEEE, 2015Konferensbidrag (Refereegranskat)
    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.

  • 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 hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    IDS rule management made easy2016Ingår i: Electronics, Computers and Artificial Intelligence (ECAI), 2016 8th International Conference on, IEEE, 2016Konferensbidrag (Refereegranskat)
    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.

  • 19.
    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 Mitigation2015Ingår 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. 265-282Konferensbidrag (Refereegranskat)
    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.

  • 20.
    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 Technologies2016Ingår i: 2016 8th IFIP International Conference onNew Technologies, Mobility and Security (NTMS), New York: IEEE, 2016, s. 1-8Konferensbidrag (Refereegranskat)
    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.

  • 21.
    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 Proxy2015Konferensbidrag (Refereegranskat)
    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.

  • 22.
    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 networks2016Ingår i: PROCEEDINGS OF THE 2016 IEEE INTERNATIONAL CONFERENCE ON WIRELESS COMMUNICATIONS, SIGNAL PROCESSING AND NETWORKING (WISPNET), IEEE, 2016, s. 828-834Konferensbidrag (Refereegranskat)
    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).

  • 23.
    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 Networks2017Ingår 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. 179-186Konferensbidrag (Refereegranskat)
    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.

  • 24.
    Aguiño, Gonzalo Iglesias
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT.
    Performance of VoIP strategies for hybrid Mobile Ad Hoc Networks2007Självständigt arbete på avancerad nivå (magisterexamen), 20 poäng / 30 hpStudentuppsats
    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.

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  • 25. 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 (Refereegranskat)
    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

  • 26. 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 (Refereegranskat)
    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

  • 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.
    Finding lower bounds of localization with noisy measurements using genetic algorithms2011Ingår 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. 47-54Konferensbidrag (Refereegranskat)
    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.

  • 28. 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 (Refereegranskat)
  • 29.
    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 measurements2012Ingår i: 2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops & PhD Forum (IPDPSW), IEEE conference proceedings, 2012, s. 601-608Konferensbidrag (Refereegranskat)
  • 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
    NICTA Australia Australian Technology Park.
    LICA: Improving Localization Given Noisy Data In GPS-Equipped VANETs Using Trilateration With Cluster Analysis2011Rapport (Refereegranskat)
  • 31.
    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 VANETs2012Ingår 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. 149-161Konferensbidrag (Refereegranskat)
  • 32.
    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 (Refereegranskat)
  • 33.
    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 (Refereegranskat)
  • 34.
    Ahlqvist, Klas
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för hälsovetenskaper (from 2013).
    Norell, Per-Ivar
    Karlstads universitet.
    Har vi verkligen ett säkert beteende på internet?: En kvalitativ studie om hur användare hanterar lösenord på internet och varför de gör som de gör.2022Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    Abstract [sv]

    Introduktion: För att kunna använda möjligheterna som internet erbjuder krävs i många fall ett användarkonto som identifierar och autentiserar användaren. En förutsättning för att det ska vara säkert är att ingen annan har tillgång till användarens kontouppgifter, vilket ställer krav på att användaren har komplexa och unika lösenord. Syfte: I denna studie har vi undersökt vilken kunskap användare har kring säkra lösenord, hur de agerar samt undersökt varför de agerar som de gör. Metod: Studien är genomförd som en kvalitativ intervjustudie med 12 respondenter i varierande ålder och bakgrund. Resultat: Våra resultat visar att användarens kunskaper ofta bygger på äldre, ej längre aktuella, rekommendationer. De har även bristande kunskaper om vad en lösenordsgenerator eller lösenordshanterare är och hur de fungerar. Kunskapsbristerna, kombinerat med önskan om att det ska gå snabbt, medför att användarna ej genomför korrekta hot- och konsekvensbedömningar av riskerna på internet. Diskussion/Slutsats: Kunskaperna hos användarna behöver höjas för att minska riskerna de utsätter sig för. Teknikutvecklingen går fort och ökad kunskap och medvetenhet krävs för ett säkert agerande på internet.

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  • 35.
    Ahmad, Iftikhar
    et al.
    University of Engineering and Technology, PAK.
    Hamid, Muhammad
    University of Engineering and Technology, PAK.
    Yousaf, Suhail
    University of Engineering and Technology, PAK.
    Tanveer Shah, Syed
    The University of Agriculture, PAK.
    Ahmad, Muhammad Ovais
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Optimizing Pretrained Convolutional Neural Networks for Tomato Leaf Disease Detection2020Ingår i: Complexity, ISSN 1076-2787, E-ISSN 1099-0526, Vol. 2020, artikel-id 8812019Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Vegetable and fruit plants facilitate around 7.5 billion people around the globe, playing a crucial role in sustaining life on the planet. The rapid increase in the use of chemicals such as fungicides and bactericides to curtail plant diseases is causing negative effects on the agro-ecosystem. The high scale prevalence of diseases in crops affects the production quantity and quality. Solving the problem of early identification/diagnosis of diseases by exploiting a quick and consistent reliable method will benefit the farmers. In this context, our research work focuses on classification and identification of tomato leaf diseases using convolutional neural network (CNN) techniques. We consider four CNN architectures, namely, VGG-16, VGG-19, ResNet, and Inception V3, and use feature extraction and parameter-tuning to identify and classify tomato leaf diseases. We test the underlying models on two datasets, a laboratory-based dataset and self-collected data from the field. We observe that all architectures perform better on the laboratory-based dataset than on field-based data, with performance on various metrics showing variance in the range 10%–15%. Inception V3 is identified as the best performing algorithm on both datasets.

  • 36.
    Ahmad, Iftikhar
    et al.
    Univ Engn & Technol, PAK.
    Yousaf, Muhammad
    Univ Engn & Technol, PAK.
    Yousaf, Suhail
    Univ Engn & Technol, PAK.
    Ahmad, Muhammad Ovais
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Fake News Detection Using Machine Learning Ensemble Methods2020Ingår i: Complexity, ISSN 1076-2787, E-ISSN 1099-0526, Vol. 2020, artikel-id 8885861Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    The advent of the World Wide Web and the rapid adoption of social media platforms (such as Facebook and Twitter) paved the way for information dissemination that has never been witnessed in the human history before. With the current usage of social media platforms, consumers are creating and sharing more information than ever before, some of which are misleading with no relevance to reality. Automated classification of a text article as misinformation or disinformation is a challenging task. Even an expert in a particular domain has to explore multiple aspects before giving a verdict on the truthfulness of an article. In this work, we propose to use machine learning ensemble approach for automated classification of news articles. Our study explores different textual properties that can be used to distinguish fake contents from real. By using those properties, we train a combination of different machine learning algorithms using various ensemble methods and evaluate their performance on 4 real world datasets. Experimental evaluation confirms the superior performance of our proposed ensemble learner approach in comparison to individual learners.

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  • 37.
    Ahmad, Muhammad Ovais
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    On the Efficiency of Supernodal Factorization in Interior-Point Method Using CPU-GPU Collaboration2020Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 8, s. 120892-120904Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Primal-dual interior-point method (PDIPM) is the most efficient technique for solving sparse linear programming (LP) problems. Despite its efficiency, PDIPM remains a compute-intensive algorithm. Fortunately, graphics processing units (GPUs) have the potential to meet this requirement. However, their peculiar architecture entails a positive relationship between problem density and speedup, conversely implying a limited affinity of GPUs for problem sparsity. To overcome this difficulty, the state-of-the-art hybrid (CPU-GPU) implementation of PDIPM exploits presence of supernodes in sparse matrices during factorization. Supernodes are groups of similar columns that can be treated as dense submatrices. Factorization method used in the state-of-the-art solver performs only selected operations related to large supernodes on GPU. This method is known to underutilize GPU’s computational power while increasing CPU-GPU communication overhead. These shortcomings encouraged us to adapt another factorization method, which processes sets of related supernodes on GPU, and introduce it to the PDIPM implementation of a popular open-source solver. Our adaptation enabled the factorization method to better mitigate the effects of round-off errors accumulated over multiple iterations of PDIPM. To augment performance gains, we also used an efficient CPU-based matrix multiplication method. When tested for a set of well-known sparse problems, the adapted solver showed average speed-ups of approximately 55X, 1.14X and 1.05X over the open-source solver’s original version, the state-of-the-art solver, and a highly optimized proprietary solver known as CPLEX, respectively. These results strongly indicate that our proposed hybrid approach can lead to significant performance gains for solving large sparse problems.

  • 38.
    Ahmad, Muhammad Ovais
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Iftikhar, Ahmad
    University of Engineering and Technology, Pakistan.
    Iqra, Sadaf Khan
    Aalto University, Finland.
    An Empirical Investigation on Electronic Government Services Continuance and Trust2023Konferensbidrag (Refereegranskat)
    Abstract [en]

    Trust is an important factor that contributes to citizens' willingness to continuance use of e-gov services. However, there is a lack of prior investigation about trust and continuance use of e-gov services in Pakistan - a developing country. We propose a model to investigate citizens' trust and e-gov services' continuous use intention to fill this research gap. Our study collected data from an online survey of 558 Pakistani citizens. Using partial least squares analysis, we found that disposition to trust positively correlates with both internet and government trust. Moreover, citizen satisfaction, trust, perceived usefulness, confirmation, and perceived risk all have significant impacts on the continuous use intention of e-gov services. This research extends and validates the Expectation-Confirmation Model by exploring key factors that influence e-gov continuance use intention. As such, our study offers valuable insights for policymakers and practitioners involved in e-gov service delivery in developing countries like Pakistan. The paper also discusses our findings' implications and identifies future research directions.

  • 39.
    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 environment2014Konferensbidrag (Refereegranskat)
    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.

  • 40.
    Ahmed, Bestoun S.
    USI SUPSI, Ist Dalle Molle Studi Intelligenza Artificiale ID, Lugano, Switzerland.;Salahaddin Univ Hawler, Software Engn Dept, Erbil, Iraq. IRQ.
    Test case minimization approach using fault detection and combinatorial optimization techniques for configuration-aware structural testing2016Ingår i: ENGINEERING SCIENCE AND TECHNOLOGY-AN INTERNATIONAL JOURNAL-JESTECH, ISSN 2215-0986, Vol. 19, nr 2, s. 737-753Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    This paper presents a technique to minimize the number of test cases in configuration-aware structural testing. Combinatorial optimization is used first to generate an optimized test suite by sampling the input configuration. Second, for further optimization, the generated test suite is filtered based on an adaptive mechanism by using a mutation testing technique. The initialized test suite is optimized using cuckoo search (CS) along with combinatorial approach, and mutation testing is used to seed different faults to the software-under-test, as well as to filter the test cases based on the detected faults. To measure the effectiveness of the technique, an empirical study is conducted on a software system. The technique proves its effectiveness through the conducted case study. The paper also shows the application of combinatorial optimization and CS to the software testing. (C) 2016, Karabuk University. Publishing services by Elsevier B.V.

  • 41. Ahmed, Bestoun S.
    et al.
    Bures, M.
    Czech Technical University, CZE.
    Testing of Smart TV applications: Key ingredients, challenges and proposed solutions2019Ingår i: Proceedings of the Future Technologies Conference / [ed] Bhatia R., Arai K., Kapoor S, Springer, 2019, Vol. 880, s. 241-256Konferensbidrag (Refereegranskat)
    Abstract [en]

    Smart TV applications are software applications that have been designed to run on smart TVs which are televisions with integrated Internet features. Nowadays, the smart TVs are going to dominate the television market, and the number of connected TVs is growing exponentially. This growth is accompanied by the increase of consumers and the use of smart TV applications that drive these devices. Due to the increasing demand for smart TV applications especially with the rise of the Internet of Things (IoT) services, it is essential to building an application with a certain level of quality. Despite the analogy between the smart TV and mobile apps, testing smart TV applications is different in many aspects due to the different nature of user interaction and development environment. To develop the field and formulate the concepts of smart TV application testing, this paper aims to provide the essential ingredients, solutions, answers to the most critical questions, and open problems. In addition, we offer initial results and proof of concepts for a creeper algorithm to detect essential views of the applications. This paper serves as an effort to report the key ingredients and challenges of the smart TV application testing systematically to the research community. © Springer Nature Switzerland AG 2019.

  • 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, Czech Republic.
    EvoCreeper: Automated Black-Box Model Generation for Smart TV Applications2019Ingår i: IEEE transactions on consumer electronics, ISSN 0098-3063, E-ISSN 1558-4127, Vol. 65, nr 2, s. 160-169Artikel i tidskrift (Refereegranskat)
    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.

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  • 43.
    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 Study2019Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 7, s. 13758-13780Artikel i tidskrift (Refereegranskat)
    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.

  • 44.
    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, SWE.
    Wasif, Afzal
    Mälardalen University, Västerås, SWE.
    Kamal Z, Zamli
    University Malaysia Pahang, Pekan, MYS.
    An evaluation of Monte Carlo-based hyper-heuristic for interaction testing of industrial embedded software applications2020Ingår i: Soft Computing - A Fusion of Foundations, Methodologies and Applications, ISSN 1432-7643, E-ISSN 1433-7479, Vol. 24, nr 18, s. 13929-13954Artikel i tidskrift (Refereegranskat)
    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.

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  • 45. Ahmed, Bestoun S.
    et al.
    Gambardella, L. M.
    Istituto Dalle Molle di Studi SullIntelligenza Artificíale (IDSIA), CHE.
    Zamli, K. Z.
    University Malaysia Pahang, MYS.
    A new approach to speed up combinatorial search strategies using stack and hash table2016Ingår i: Proceedings of 2016 SAI Computing Conference, SAI 2016, Institute of Electrical and Electronics Engineers (IEEE), 2016, s. 1217-1222Konferensbidrag (Refereegranskat)
    Abstract [en]

    Owing to the significance of combinatorial search strategies both for academia and industry, the introduction of new techniques is a fast growing research field these days. These strategies have really taken different forms ranging from simple to complex strategies in order to solve all forms of combinatorial problems. Nonetheless, despite the kind of problem these approaches solve, they are prone to heavy computation with the number of combinations and growing search space dimensions. This paper presents a new approach to speed up the generation and search processes using a combination of stack and hash table data structures. This approach could be put to practice for the combinatorial approaches to speed up the generation of combinations and search process in the search space. Furthermore, this new approach proved its performance in diverse stages better than other known strategies. © 2016 IEEE.

  • 46.
    Ahmed, Bestoun S.
    et al.
    Ist Dalle Molle Studi sullIntelligenza Artificial, CH-6928 Manno Lugano, Switzerland.;Czech Tech Univ, Fac Elect Engn, Dept Comp Sci, Karlovo Nam 13, Prague 12135 2, Czech Republic. CZE.
    Gambardella, Luca M.
    Ist Dalle Molle Studi sullIntelligenza Artificial, CH-6928 Manno Lugano, Switzerland. CHE.
    Afzal, Wasif
    Mlardalen Univ, Sch Innovat Design & Engn, Vasteras, Sweden..
    Zamli, Kamal Z.
    Univ Malaysia Pahang, Fac Comp Syst & Software Engn, Gambang, Malaysia. MYS.
    Handling constraints in combinatorial interaction testing in the presence of multi objective particle swarm and multithreading2017Ingår i: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 86, s. 20-36Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Context: Combinatorial testing strategies have lately received a lot of attention as a result of their diverse applications. In its simple form, a combinatorial strategy can reduce several input parameters (configurations) of a system into a small set based on their interaction (or combination). In practice, the input configurations of software systems are subjected to constraints, especially in case of highly configurable systems. To implement this feature within a strategy, many difficulties arise for construction. While there are many combinatorial interaction testing strategies nowadays, few of them support constraints. Objective: This paper presents a new strategy, to construct combinatorial interaction test suites in the presence of constraints. Method: The design and algorithms are provided in detail. To overcome the multi-judgement criteria for an optimal solution, the multi-objective particle swarm optimisation and multithreading are used. The strategy and its associated algorithms are evaluated extensively using different benchmarks and comparisons. Results: Our results are promising as the evaluation results showed the efficiency and performance of each algorithm in the strategy. The benchmarking results also showed that the strategy can generate constrained test suites efficiently as compared to state-of-the-art strategies. Conclusion: The proposed strategy can form a new way for constructing of constrained combinatorial interaction test suites. The strategy can form a new and effective base for future implementations. (C) 2017 Elsevier B.V. All rights reserved.

  • 47.
    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 Testing2019Ingår i: EASE '19 Proceedings of the Evaluation and Assessment on Software Engineering, NY, USA: Association for Computing Machinery (ACM), 2019, s. 252-258Konferensbidrag (Refereegranskat)
    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.

  • 48.
    Ahmed, Bestoun S.
    et al.
    Ist Dalle Molle Studi SullIntelligenza Artificial, CH-6928 Manno Lugano, Switzerland.;Salahaddin Univ, Engn Coll, Software & Informat Engn Dept, Erbil, Kurdistan Regio, Iraq. IRQ.
    Sahib, Mouayad A.
    Salahaddin Univ, Engn Coll, Software & Informat Engn Dept, Erbil, Kurdistan Regio, Iraq. IRQ.
    Gambardella, Luca M.
    Ist Dalle Molle Studi SullIntelligenza Artificial, CH-6928 Manno Lugano, Switzerland. CHE.
    Afzal, Wasif
    Malardalen Univ, Sch Innovat Design & Engn, Vasteras, Sweden..
    Zamli, Kamal Z.
    Univ Malaysia Pahang Lebuhraya Tun Rezak, Fac Comp Syst & Software Engn, IBM Ctr Excellence, Kuantan 26300, Pahang Darul Ma, Malaysia. MYS.
    Optimum Design of (PID mu)-D-lambda controller for an automatic voltage regulator system using combinatorial test design2016Ingår i: PLOS ONE, E-ISSN 1932-6203, Vol. 11, nr 11, artikel-id e0166150Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Combinatorial test design is a plan of test that aims to reduce the amount of test cases systematically by choosing a subset of the test cases based on the combination of input variables. The subset covers all possible combinations of a given strength and hence tries to match the effectiveness of the exhaustive set. This mechanism of reduction has been used successfully in software testing research with t-way testing (where t indicates the interaction strength of combinations). Potentially, other systems may exhibit many similarities with this approach. Hence, it could form an emerging application in different areas of research due to its usefulness. To this end, more recently it has been applied in a few research areas successfully. In this paper, we explore the applicability of combinatorial test design technique for Fractional Order (FO), Proportional-Integral-Derivative (PID) parameter design controller, named as FOPID, for an automatic voltage regulator (AVR) system. Throughout the paper, we justify this new application theoretically and practically through simulations. In addition, we report on first experiments indicating its practical use in this field. We design different algorithms and adapted other strategies to cover all the combinations with an optimum and effective test set. Our findings indicate that combinatorial test design can find the combinations that lead to optimum design. Besides this, we also found that by increasing the strength of combination, we can approach to the optimum design in a way that with only 4-way combinatorial set, we can get the effectiveness of an exhaustive test set. This significantly reduced the number of tests needed and thus leads to an approach that optimizes design of parameters quickly.

  • 49.
    Ahmed, Bestoun S.
    et al.
    Czech Tech Univ, Fac Elect Engn, Dept Comp Sci, Software Testing Intelligent Lab, Prague 12135, Czech Republic. CZE.
    Zamli, Kamal Z.
    Univ Malaysia Pahang, Fac Comp Syst & Software Engn, Gambang 26300, Malaysia. MYS.
    Afzal, Wasif
    Malardalen Univ, Sch Innovat Design & Engn, S-72123 Vasteras, Sweden..
    Bures, Miroslav
    Czech Tech Univ, Fac Elect Engn, Dept Comp Sci, Software Testing Intelligent Lab, Prague 12135, Czech Republic. CZE.
    Constrained interaction testing: A systematic literature study2017Ingår i: IEEE Access, E-ISSN 2169-3536, Vol. 5, s. 25706-25730Artikel i tidskrift (Refereegranskat)
    Abstract [en]

    Interaction testing can be used to effectively detect faults that are otherwise difficult to find by other testing techniques. However, in practice, the input configurations of software systems are subjected to constraints, especially in the case of highly configurable systems. Handling constraints effectively and efficiently in combinatorial interaction testing is a challenging problem. Nevertheless, researchers have attacked this challenge through different techniques, and much progress has been achieved in the past decade. Thus, it is useful to reflect on the current achievements and shortcomings and to identify potential areas of improvements. This paper presents the first comprehensive and systematic literature study to structure and categorize the research contributions for constrained interaction testing. Following the guidelines of conducting a literature study, the relevant data are extracted from a set of 103 research papers belonging to constrained interaction testing. The topics addressed in constrained interaction testing research are classified into four categories of constraint test generation, application, generation and application, and model validation studies. The papers within each of these categories are extensively reviewed. Apart from answering several other research questions, this paper also discusses the applications of constrained interaction testing in several domains, such as software product lines, fault detection and characterization, test selection, security, and graphical user interface testing. This paper ends with a discussion of limitations, challenges, and future work in the area.

  • 50.
    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 Frameworks2017Självständigt arbete på grundnivå (kandidatexamen), 10 poäng / 15 hpStudentuppsats (Examensarbete)
    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.

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