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  • 301. Budurushi, Jurlind
    Volkamer, Melanie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    "E-Mail made in Germany": Untersuchung der Sicherheitsbeurteilung von E-Mail-Nutzern2016In: Datenschutz und Datensicherheit - DuD, ISSN 1614-0702, E-ISSN 1862-2607, Vol. 40, no 5, p. 300-304Article in journal (Other academic)
  • 302.
    Budurushi, Jurlind
    et al.
    Detecon Int GmbH, Cologne, Germany.
    Neumann, Stephan
    Tech Univ Darmstadt, Darmstadt, Germany.
    Renaud, Karen
    Abertay Univ, Dundee, Scotland; Univ South Africa, Pretoria, South Africa.
    Volkamer, Melanie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Tech Univ Darmstadt, Darmstadt, Germany.
    Introduction to special issue on e-voting2018In: Journal of Information Security and Applications, ISSN 2214-2134, E-ISSN 2214-2126, Vol. 38, p. 122-123Article in journal (Refereed)
  • 303. Budurushi, Jurlind
    et al.
    Volkamer, Melanie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Feasibility Analysis of Various Electronic Voting Systems for Complex Elections2014In: International Conference for E-Democracy and Open Government 2014 / [ed] Peter Parycek & Noella Edelmann, Krems: Donau-Universität , 2014, p. 141-152Conference paper (Refereed)
  • 304.
    Budzisz, Łukasz
    et al.
    Technische Universität Berlin, Berlin, Germany.
    Garcia, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ferrús, Ramon
    Universitat Politècnica de Catalunya, Barcelona, Spain.
    A taxonomy and survey of SCTP research2012In: ACM Computing Surveys, ISSN 0360-0300, E-ISSN 1557-7341, Vol. 44, no 4, p. -36, article id 18Article in journal (Refereed)
    Abstract [en]

    The Stream Control Transmission Protocol (SCTP) is a relatively recent general-purpose transport layer protocol for IP networks that has been introduced as a complement to the well-established TCP and UDP transport protocols. Although initially conceived for the transport of PSTN signaling messages over IP networks, the introduction of key features in SCTP, such as multihoming and multistreaming, has spurred considerable research interest surrounding SCTP and its applicability to different networking scenarios. This article aims to provide a detailed survey of one of these new features—multihoming—which, as it is shown, is the subject of evaluation in more than half of all published SCTP-related articles. To this end, the article first summarizes and organizes SCTP-related research conducted so far by developing a four-dimensional taxonomy reflecting the (1) protocol feature examined, (2) application area, (3) network environment, and (4) study approach. Over 430 SCTP-related publications have been analyzed and classified according to the proposed taxonomy. As a result, a clear perspective on this research area in the decade since the first protocol standardization in 2000 is given, covering both current and future research trends. On continuation, a detailed survey of the SCTP multihoming feature is provided, examining possible applications of multihoming, such as robustness, handover support, and loadsharing.

  • 305.
    Bui, Michael
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Pedersen, Magnus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Implementation of a Log Agent in Microsoft Azure: and packaging it to Azure Marketplace2015Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Cloud computing is still in an early stage of development and Microsoft is now investing considerable amount of resources in the cloud. Microsoft Azure is a cloud platform developed by Microsoft and it is continuously evolving, new features are constantly being added and old features are being updated. Integration Software, which is a company that focuses on products for system integration strongly believes that cloud­-based solutions will have a significant impact on their future. This is why selling and developing solutions and services for the cloud are strategically important for them.

    The objective of this dissertation is to investigate Microsoft Azure in general and Azure Marketplace in particular. This investigation consisted of an implementation of a Microsoft Azure application and integrating this application with Azure Marketplace and evaluating the expenses for running the application. The purpose for this project is to gain practical experience and to work with new techniques and help Integration Software better understand Azure Marketplace.

    The application is a Log Agent which fetches data from an external source and resends the data to an external party (Integration Manager). Our first intention was to package and deploy the application to a newly updated Azure Marketplace. The new Azure Marketplace was never released during this dissertation so we decided to deploy the application to the existing version of Azure Marketplace. This was however not fully successful. We encountered some problems in successfully deploying the application to Azure Marketplace. The evaluations for the cost of running an Azure application were not carried out due to lack of time.

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  • 306.
    Buljubasic, Ajdin
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Implementation and evaluation of a secure communication solution for drones in a ROS2 network application2023Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    In recent time, drones are everywhere. While commercial drones have shown great potential for hobby enthusiasts, it has shown a greater potential in military use and safeguarding. Currently, a significant amount of drones are being used for malicious means, such as espionage and warfare. Because of this, these drones has to be combated. One way to combat them is to use countermeasure drones. In this thesis, the objective is to implement and evaluate the security capabilities of SROS2 in a simulated environment. The thesis goal is to create a simulated environment along with two “ally” drones with secure communication and one “enemy” drone that will try to eavesdrop on their communication. Completing the thesis work was done by configuring a drone network using ROS2’s subscriber-publisher model and the use of evaluating methods such as Wireshark, tcpdump, and overhead performance tests to better understand and form a clearer picture of the inner-workings of the security capabilities offered by SROS2. The result yielded a simulated environment with three drones, where the “ally” drones successfully communicated with each other and the “enemy” drone failed in eavesdropping on the data travelling between them. SROS2’s security offered security but also showcased a decrease in latency and throughput performance, compared to a non-configured SROS2 network.

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  • 307.
    Bures, M.
    et al.
    FEE, Czech Technical University, CZE.
    Cerny, T.
    Baylor University, USA.
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). FEE, Czech Technical University, CZE.
    Internet of things: Current challenges in the quality assurance and testing methods2019In: Information Science and Applications 2018. ICISA / [ed] K Kim ; N Baek N, 2019, p. 625-634Conference paper (Refereed)
    Abstract [en]

    Contemporary development of the Internet of Things (IoT) technology brings a number of challenges in the Quality Assurance area. Current issues related to security, user’s privacy, the reliability of the service, interoperability, and integration are discussed. All these create a demand for specific Quality Assurance methodology for the IoT solutions. In the paper, we present the state of the art of this domain and we discuss particular areas of system testing discipline, which is not covered by related work sufficiently so far. This analysis is supported by results of a recent survey we performed among ten IoT solutions providers, covering various areas of IoT applications. © 2019, Springer Nature Singapore Pte Ltd.

  • 308.
    Bures, M.
    et al.
    Czech Technical University in Prague, CZE.
    Klima, M.
    Czech Technical University in Prague, CZE.
    Rechtberger, V.
    Czech Technical University in Prague, CZE.
    Bellekens, X.
    University of Strathclyde, GBR.
    Tachtatzis, C.
    University of Strathclyde, GBR.
    Atkinson, R.
    University of Strathclyde, GBR.
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Czech Technical University in Prague, CZE.
    Interoperability and Integration Testing Methods for IoT Systems: A Systematic Mapping Study2020In: Lecture Notes in Computer Science (including subseries Lecture Notes in Artificial Intelligence and Lecture Notes in Bioinformatics), Springer Science+Business Media B.V., 2020, p. 93-112Conference paper (Refereed)
    Abstract [en]

    The recent active development of Internet of Things (IoT) solutions in various domains has led to an increased demand for security, safety, and reliability of these systems. Security and data privacy are currently the most frequently discussed topics; however, other reliability aspects also need to be focused on to maintain smooth and safe operation of IoT systems. Until now, there has been no systematic mapping study dedicated to the topic of interoperability and integration testing of IoT systems specifically; therefore, we present such an overview in this study. We analyze 803 papers from four major primary databases and perform detailed assessment and quality check to find 115 relevant papers. In addition, recently published testing techniques and approaches are analyzed and classified; the challenges and limitations in the field are also identified and discussed. Research trends related to publication time, active researchers, and publication media are presented in this study. The results suggest that studies mainly focus only on general testing methods, which can be applied to integration and interoperability testing of IoT systems; thus, there are research opportunities to develop additional testing methods focused specifically on IoT systems, so that they are more effective in the IoT context.

  • 309.
    Bures, Miroslav
    et al.
    Czech Technical University, Czech Republic.
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Czech Technical University, Czech Republic.
    Employment of multiple algorithms for optimal path-based test selection strategy2019In: Information and Software Technology, ISSN 0950-5849, E-ISSN 1873-6025, Vol. 114, p. 21-36Article in journal (Refereed)
    Abstract [en]

    Context

    Executing various sequences of system functions in a system under test represents one of the primary techniques in software testing. The natural method for creating effective, consistent and efficient test sequences is to model the system under test and employ an algorithm to generate tests that satisfy a defined test coverage criterion. Several criteria for preferred test set properties can be defined. In addition, to optimize the test set from an economic viewpoint, the priorities of the various parts of the system model under test must be defined.

    Objective

    Using this prioritization, the test cases exercise the high-priority parts of the system under test by more path combinations than those with low priority (this prioritization can be combined with the test coverage criterion that determines how many path combinations of the individual parts of the system are tested). Evidence from the literature and our observations confirm that finding a universal algorithm that produces a test set with preferred properties for all test coverage criteria is a challenging task. Moreover, for different individual problem instances, different algorithms provide results with the best value of a preferred property. In this paper, we present a portfolio-based strategy to perform the best test selection.

    Method

    The proposed strategy first employs a set of current algorithms to generate test sets; then, a preferred property of each test set is assessed in terms of the selected criterion, and finally, the test set with the best value of a preferred property is chosen.

    Results

    The experimental results confirm the validity and usefulness of this strategy. For individual instances of 50 system under test models, different algorithms provided results having the best preferred property value; these results varied by the required test coverage level, the size of the priority parts of the model, and the selected test set preferred property criteria.

    Conclusion

    In addition to the used algorithms, the proposed strategy can be used to assess the optimality of different path-based testing algorithms and choose a suitable algorithm for the testing.

  • 310.
    Bures, Miroslav
    et al.
    Czech Tech Univ, Dept Comp Sci, FEE, Prague, Czech Republic.
    Ahmed, Bestoun. S
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Rechtberger, Vaclav
    Czech Tech Univ, Dept Comp Sci, FEE, Prague, Czech Republic.
    Klima, Matej
    Czech Tech Univ, Dept Comp Sci, FEE, Prague, Czech Republic.
    Trnka, Michal
    Czech Tech Univ, Dept Comp Sci, FEE, Prague, Czech Republic.
    Jaros, Miroslav
    Red Hat Czech Sro, Brno, Czech Republic.
    Bellekens, Xavier
    Univ Strathclyde, Dept Elect & Elect Engn, Glasgow, Lanark, Scotland.
    Almog, Dani
    Shamoon Coll Engn, Software Engn Dept, Beer Sheva, Israel.
    Herout, Pavel
    Univ West Bohemia, Dept CS & Engn, FAS, Plzen, Czech Republic.
    PatrIoT: IoT Automated Interoperability and Integration Testing Framework2021In: IEEE International Conference on Software Testing Verification and Validation, IEEE, 2021, p. 454-459, article id 9438582Conference paper (Refereed)
    Abstract [en]

    With the rapid growth of the contemporary Internet of Things (IoT) market, the established systems raise a number of concerns regarding the reliability and the potential presence of critical integration defects. In this paper, we present a PatrIoT framework that aims to provide flexible support to construct an effective IoT system testbed to implement automated interoperability and integration testing. The framework allows scaling from a pure physical testbed to a simulated environment using a number of predefined modules and elements to simulate an IoT device or part of the tested infrastructure. PatrIoT also contains a set of reference example testbeds and several sets of example automated tests for a smart street use case. 

  • 311.
    Bures, Miroslav
    et al.
    Czech Technical University in Prague, Czechia.
    Klima, Matej
    Czech Technical University in Prague, Czechia.
    Rechtberger, Vaclav
    Czech Technical University in Prague, Czechia.
    Ahmed, Bestoun. S
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Hindy, Hanan
    Abertay University, UK.
    Bellekens, Xavier
    University of Strathclyde, UK.
    Review of Specific Features and Challenges in the Current Internet of Things Systems Impacting Their Security and Reliability2021In: Trends and Applications in Information Systems and Technologies, Springer, 2021, Vol. 1367Conference paper (Refereed)
    Abstract [en]

    The current development of the Internet of Things (IoT) technology poses significant challenges to researchers and industry practitioners. Among these challenges, security and reliability particularly deserve attention. In this paper, we provide a consolidated analysis of the root causes of these challenges, their relations, and their possible impacts on IoT systems’ general quality characteristics. Further understanding of these challenges is useful for IoT quality engineers when defining testing strategies for their systems and researchers to consider when discussing possible research directions. In this study, twenty specific features of current IoT systems are discussed, divided into five main categories: (1) Economic, managerial and organisational aspects, (2) Infrastructural challenges, (3) Security and privacy challenges, (4) Complexity challenges and (5) Interoperability problems. 

  • 312.
    Bures, Miroslav
    et al.
    Czech Technical University, Czechia.
    Macik, Miroslav
    Czech Technical University, Czechia.
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Czech Technical University, Czechia.
    Rechtberger, Vaclav
    Czech Technical University, Czechia.
    Slavik, Pavel
    Czech Technical University, Czechia.
    Testing the Usability and Accessibility of Smart TV Applications Using an Automated Model-based Approach2020In: IEEE transactions on consumer electronics, ISSN 0098-3063, E-ISSN 1558-4127, Vol. 66, no 2, p. 134-143Article in journal (Refereed)
    Abstract [en]

    As the popularity of Smart Televisions (TVs) and interactive Smart TV applications (apps) has recently grown, the usability of these apps has become an important quality characteristic. Previous studies examined Smart TV apps from a usability perspective. However, these methods are mainly manual, and the potential of automated model-based testing methods for usability testing purposes has not yet been fully explored. In this paper, we propose an approach to test the usability of Smart TV apps based on the automated generation of a Smart TV user interaction model from an existing app by a specialized automated crawler. By means of this model, defined user tasks in the Smart TV app can be evaluated automatically in terms of their feasibility and estimated user effort, which reflects the usability of the analyzed app. This analysis can be applied in the context of regular users and users with various specific needs. The findings from this model-based automated analysis approach can be used to optimize the user interface of a Smart TV app to increase its usability, accessibility, and quality.

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  • 313.
    Bönström, Daniel
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Smartphone application in PhoneGap: M2C’s electric vehicle smart charger2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
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  • 314. Camenisch, Jan
    et al.
    Crispo, Bruno
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Leenes, Ronald
    Russello, Giovanni
    Privacy and Identity Management for Life: 7th IFIP WG 9.2, 9.6/11.7, 11.4, 11.6 International Summer School, Trento, Italy, September 5-9, 2011. Revised Selected Papers2012Book (Refereed)
  • 315. Canova, Gamze
    et al.
    Volkamer, Melanie
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Weiler, Simon
    Poster: Password Entering and Transmission Security2014Other (Other academic)
    Abstract [en]

    The most popular form of user authentication on websites is the use of passwords. When entering a password, it is crucial that the website uses HTTPS (for the entire content). However, this is often not the case. We propose PassSec - a Firefox Add-On to support users to detect password fields on which their password might be endangered. In addition, PassSec displays a non-blocking warning next to the password field, once users click into the password field. The user is provided with possible consequences of entering a password, recommendations and further information if wanted. 

  • 316.
    Cardellini, Valeria
    et al.
    University of Rome Tor Vergata, Italy.
    Galinac Grbac, Tihana
    University or Rijeka, Croatia .
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kathiravelu, Pradeeban
    Universidade de Lisboa, Portugal.
    Lo Presti, Francesco
    University or Rome tor Vergata, Italy.
    Marotta, Antonio
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Nardelli, Matteo
    University of Rome Tor Vergata, Italy.
    Luís, Veiga
    Universidade de Lisboa, Portugal.
    Integrating SDN and NFV with QoS-Aware Service Composition Cardellini2018In: Autonomous Control for a Reliable Internet of Services: Methods, Models, Approaches, Techniques, Algorithms, and Tools / [ed] Ivan Ganchev; Robert D. van der Mei; J.L. van den Berg, Cham, Switzerland: Springer, 2018, 1, p. 212-240Chapter in book (Refereed)
    Abstract [en]

    Traditional networks are transformed to enable full integrationof heterogeneous hardware and software functions, that are configuredat runtime, with minimal time to market, and are provided to theirend users on “as a service” principle. Therefore, a countless number ofpossibilities for further innovation and exploitation opens up. NetworkFunction Virtualization (NFV) and Software-Defined Networking (SDN)are two key enablers for such a new flexible, scalable, and service-orientednetwork architecture. This chapter provides an overview of QoS-awarestrategies that can be used over the levels of the network abstractionaiming to fully exploit the new network opportunities. Specifically, wepresent three use cases of integrating SDN and NFV with QoS-awareservice composition, ranging from the energy efficient placement of virtualnetwork functions inside modern data centers, to the deployment ofdata stream processing applications using SDN to control the networkpaths, to exploiting SDN for context-aware service compositions.

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  • 317.
    Carlsson, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    On the Use of 5G for Smart Grid Inter-Substation Control Signaling2019Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    In the energy domain today we are seeing an increasing number of energy equipments used and faceing new challenges such as network reliability, distributed renewable energy, increasing network complexity and energy efficiency. The concept of smart grid control systems has recently been seen as an appropriate way to address these new challenges.

    Today, the IEC 61850 standard is one of the most common standards used for power system automation. One of the services introduced is the so-called Generic Object Oriented Substation Event (GOOSE), which is a protocol to transfer time critical messages between multiple devices in a substation. The 5th generation of mobile networks (5G) are enabling new services and applications requiring lower latency, improved energy efficiency, better reliability and massive connection density. These promises of higher reliability and lower latency could then possibly be used in the future smart grid transmissions.

    In this work, the main goal was to understand the importance of time-critical messages, such as GOOSE messages, in the IEC61850 standard, and how these possibly could be used in the new 5th generation of mobile network. A proposed experimental setup which can be used for future research within both the GOOSE messaging area itself and the Open5GCore for emulated 5G mobile networks is presented. The intension of the experimental study is to send the GOOSE messages traversing through 5G networks by Open5GCore - an emulated 5G software.

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  • 318.
    Carlsson, Maria
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Elevers rimlighetsbedömning när de löser olika typer av problemlösningsuppgifter2017Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    This study aims to find out how different types of problem solving tasks affect students’ ability to plausible evaluate their solutions and answers. The study also intends to find out how students relate to reality when solving different types of problem solving tasks. In order to achieve the purpose of the study, a survey was conducted in several classes with grade two students (age 8). The results of the survey shows that the type of problem solving tasks can partially affect the students’ ability to assess plausibility. The results of the survey also shows that different types of problem solving tasks, affect how much the students reflect to reality. During the study it also became clear that the oral reasoning is crucial to perceive in order to be able to assess how students come to solutions and answers. Much of the ability to assess plausibility emerges through oral reasoning and is therefore very difficult to detect in written answers.  

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  • 319.
    Casas, Israel
    et al.
    The University of Sydney, Sydney, Australia.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ranjan, Rajiv
    CSIRO, Australia.
    Wang, Lizhe
    School of Computer Science, China University of Geosciences, China.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    GA-ETI: An enhanced genetic algorithm for the scheduling of scientific workflows in cloud environments2018In: Journal of Computational Science, ISSN 1877-7503, E-ISSN 1877-7511, Vol. 26, p. 318-331Article in journal (Refereed)
  • 320.
    Casas, Israel
    et al.
    Australia.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ranjan, Rajiv
    Australia, UK.
    Wang, Lizhe
    China.
    Zomaya, Albert Y.
    Australia.
    A balanced scheduler with data reuse and replication for scientific workflows in cloud computing systems2017In: Future generations computer systems, ISSN 0167-739X, E-ISSN 1872-7115, Vol. 74, p. 168-178Article in journal (Refereed)
    Abstract [en]

    Cloud computing provides substantial opportunities to researchers who demand pay-as-you-go computing systems. Although cloud provider (e.g., Amazon Web Services) and application provider (e.g., biologists, physicists, and online gaming companies) both have specific performance requirements (e.g. application response time), it is the cloud scheduler’s responsibility to map the application to underlying cloud resources. This article presents a Balanced and file Reuse-Replication Scheduling (BaRRS) algorithm for cloud computing environments to optimally schedule scientific application workflows. BaRRS splits scientific workflows into multiple sub-workflows to balance system utilization via parallelization. It also exploits data reuse and replication techniques to optimize the amount of data that needs to be transferred among tasks at run-time. BaRRS analyzes the key application features (e.g., task execution times, dependency patterns and file sizes) of scientific workflows for adapting existing data reuse and replication techniques to cloud systems. Further, BaRRS performs a trade-off analysis to select the optimal solution based on two optimization constraints: execution time and monetary cost of running scientific workflows. BaRRS is compared with a state-of-the-art scheduling approach; experiments prove its superior performance. Experiments include four well known scientific workflows with different dependency patterns and data file sizes. Results were promising and also highlighted most critical factors affecting execution of scientific applications on clouds. 

  • 321.
    Casas, Israel
    et al.
    University of Sydney, Australia; CSIRO, Data61, Canberra, ACT, Australia.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ranjan, Rajiv
    Newcastle University, England ; CSIRO, Data61, Canberra, ACT, Australia.
    Zomaya, Albert Y.
    University of Sydney, Australia.
    PSO-DS: a scheduling engine for scientific workflow managers2017In: Journal of Supercomputing, ISSN 0920-8542, E-ISSN 1573-0484, Vol. 73, no 9, p. 3924-3947Article in journal (Refereed)
    Abstract [en]

    Cloud computing, an important source of computing power for the scientific community, requires enhanced tools for an efficient use of resources. Current solutions for workflows execution lack frameworks to deeply analyze applications and consider realistic execution times as well as computation costs. In this study, we propose cloud user-provider affiliation (CUPA) to guide workflow's owners in identifying the required tools to have his/her application running. Additionally, we develop PSO-DS, a specialized scheduling algorithm based on particle swarm optimization. CUPA encompasses the interaction of cloud resources, workflow manager system and scheduling algorithm. Its featured scheduler PSO-DS is capable of converging strategic tasks distribution among resources to efficiently optimize makespan and monetary cost. We compared PSO-DS performance against four well-known scientific workflow schedulers. In a test bed based on VMware vSphere, schedulers mapped five up-to-date benchmarks representing different scientific areas. PSO-DS proved its efficiency by reducing makespan and monetary cost of tested workflows by 75 and 78%, respectively, when compared with other algorithms. CUPA, with the featured PSO-DS, opens the path to develop a full system in which scientific cloud users can run their computationally expensive experiments.

  • 322.
    Caso, G.
    et al.
    Simula Metropolitan CDE, NOR.
    Kousias, K.
    Simula Research Laboratory, NOR.
    Alay, O.
    University of Oslo, NOR; Simula Metropolitan CDE, NOR.
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Neri, M.
    Rohde & Schwarz, ITA .
    NB-IoT Random Access: Data-driven Analysis and ML-based Enhancements2021In: IEEE Internet of Things Journal, ISSN 2327-4662Article in journal (Refereed)
    Abstract [en]

    In the context of massive Machine Type Communications (mMTC), the Narrowband Internet of Things (NB-IoT) technology is envisioned to efficiently and reliably deal with massive device connectivity. Hence, it relies on a tailored Random Access (RA) procedure, for which theoretical and empirical analyses are needed for a better understanding and further improvements. This paper presents the first data-driven analysis of NB-IoT RA, exploiting a large scale measurement campaign. We show how the RA procedure and performance are affected by network deployment, radio coverage, and operators’ configurations, thus complementing simulation-based investigations, mostly focused on massive connectivity aspects. Comparison with the performance requirements reveals the need for procedure enhancements. Hence, we propose a Machine Learning (ML) approach, and show that RA outcomes are predictable with good accuracy by observing radio conditions. We embed the outcome prediction in a RA enhanced scheme, and show that optimized configurations enable a power consumption reduction of at least 50%. We also make our dataset available for further exploration, toward the discovery of new insights and research perspectives.

  • 323.
    Caso, Giuseppe
    et al.
    Simula Metropolitan Center for Digital Engineering, NOR.
    Alay, Ozgu
    Simula Metropolitan Center for Digital Engineering, NOR.
    Ferrante, Guido Carlo
    Ericsson Research.
    De Nardis, Luca
    Sapienza University, ITA.
    Di Benedetto, Maria-Gabriella
    Sapienza University, ITA.
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    User-Centric Radio Access Technology Selection: A Survey of Game Theory Models and Multi-Agent Learning Algorithms2021In: IEEE Access, E-ISSN 2169-3536, Vol. 9, p. 84417-84464Article in journal (Refereed)
    Abstract [en]

    User-centric radio access technology (RAT) selection is a key communication paradigm, given the increased number of available RATs and increased cognitive capabilities at the user end. When considered against traditional network-centric approaches, user-centric RAT selection results in reduced network-side management load, and leads to lower operational costs for RATs, as well as improved quality of service (QoS) and quality of experience (QoE) for users. The complex between-users interactions involved in RAT selection require, however, specific analyses, toward developing reliable and efficient schemes. Two theoretical frameworks are most often applied to user-centric RAT selection analysis, i.e., game theory (GT) and multi-agent learning (MAL). As a consequence, several GT models and MAL algorithms have been recently proposed to solve the problem at hand. A comprehensive discussion of such models and algorithms is, however, currently missing. Moreover, novel issues introduced by next-generation communication systems also need to be addressed. This paper proposes to fill the above gaps by providing a unified reference for both ongoing research and future research directions in the field. In particular, the review addresses the most common GT and MAL models and algorithms, and scenario settings adopted in user-centric RAT selection in terms of utility function and network topology. Regarding GT, the review focuses on non-cooperative models, because of their widespread use in RAT selection; as for MAL, a large number of algorithms are described, ranging from game-theoretic to reinforcement learning (RL) schemes, and also including most recent approaches, such as deep RL (DRL) and multi-armed bandit (MAB). Models and algorithms are analyzed by comparatively reviewing relevant literature. Finally, open challenges are discussed, in light of ongoing research and standardization activities.

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  • 324.
    Caso, Giuseppe
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Alay, Özgü
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). University of Oslo, Norway.
    Brunstrom, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Koumaras, Harilaos
    NCSR “Demokritos”, Institute of Informatics and Telecommunications, Greece.
    Díaz Zayas, Almudena
    University of Malaga, Spain.
    Frascolla, Valerio
    Intel Deutschland GmbH, Germany.
    Experimentation in 5G and beyond Networks: State of the Art and the Way Forward2023In: Sensors, E-ISSN 1424-8220, Vol. 23, no 24, article id 9671Article in journal (Refereed)
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  • 325.
    Caso, Giuseppe
    et al.
    Simula Research Laboratory, Norway.
    Alay, Özgü
    Simula Research Laboratory, Norway.
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstads universitet.
    Rajiullah, Mohammad
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Karlstads universitet.
    Karlsson, Jonas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Grinnemo, Karl-Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Aumayr, Erik
    Ericsson.
    Bosneag, Anne-Marie
    Ericsson.
    Xilouris, Georgious
    NCSR Demokritos, GRC.
    Oikonomakis, Andreas
    NCSR Demokritos, GRC.
    Anagnostopoulos, Themistoklis
    NCSR Demokritos, GRC.
    Koumaras, Harilaous
    NCSR Demokritos, GRC.
    Dias-Zayas, Almudena
    NCSR Demokritos, GRC.
    Garcia, Bruno
    NCSR Demokritos, GRC.
    Emmelmann, Marc
    FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. (FhG), DEU.
    Eichhorn, Fabian
    FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. (FhG), DEU.
    Briedigkeit, Thomas
    FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. (FhG), DEU.
    Rajaguru, Santosh Kumar
    FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. (FhG), DEU.
    Prakash, Arun
    FRAUNHOFER GESELLSCHAFT ZUR FOERDERUNG DER ANGEWANDTEN FORSCHUNG E.V. (FhG), DEU.
    Jimeno, Elisa
    ATOS SPAIN SA, ESP.
    Sakkas, Christos
    INFOLYSIS P.C..
    Matzakos, Panos
    EURECOM.
    Pretel, Ivan
    FON TECHNOLOGY SL.
    Reichert, L.
    HUMBOLDT-UNIVERSITÄT ZU BERLIN, DEU.
    Schoppmann, Phillipp
    HUMBOLDT-UNIVERSITÄT ZU BERLIN, DEU.
    Gutierrez, Jesus Teran
    IHP GMBH – INNOVATIONS FOR HIGH PERFORMANCE MICROELECTRONICS/LEIBNIZ-INSTITUT FUER INNOVATIVE MIKROELEKTRONIK.
    Phinikarides, Alexander
    PRIMETEL PLC.
    Monitoring and Analytics (Release A)2019Report (Refereed)
    Abstract [en]

    This document describes the design and implementation of the 5GENESIS Monitoring & Analytics (M&A) framework (Release A), developed within Task T3.3 of the Project work plan.

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  • 326.
    Caso, Giuseppe
    et al.
    Simula Metropolitan CDE, NOR.
    Alay, Özgü
    University of Oslo, NOR; Simula Metropolitan CDE, NOR.
    De Nardis, Luca De
    Sapienza University of Rome, ITA.
    Brunström, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Neri, Marco
    Rohde&Schwarz.
    Di Benedetto, Maria Gabriella
    Sapienza University of Rome, ITA.
    Empirical Models for NB-IoT Path Loss in an Urban Scenario2021In: IEEE Internet of Things Journal, ISSN 2327-4662, Vol. 8, no 17, p. 13774-13788Article in journal (Refereed)
    Abstract [en]

    The lack of publicly available large scale measurements has hindered the derivation of empirical path loss (PL) models for Narrowband Internet of Things (NB-IoT). Therefore, simulation-based investigations currently rely on models conceived for other cellular technologies, which are characterized, however, by different available bandwidth, carrier frequency, and infrastructure deployment, among others. In this paper, we take advantage of data from a large scale measurement campaign in the city of Oslo, Norway, to provide the first empirical characterization of NB-IoT PL in an urban scenario. For the PL average term, we characterize Alpha-Beta-Gamma (ABG) and Close-In (CI) models. By analyzing multiple NBIoT cells, we propose a statistical PL characterization, i.e., the model parameters are not set to a single, constant value across cells, but are randomly extracted from well-known distributions. Similarly, we define the PL shadowing distribution, correlation over distance, and inter-site correlation. Finally, we give initial insights on outdoor-to-indoor propagation, using measurements up to deep indoor scenarios. The proposed models improve PL estimation accuracy compared to the ones currently adopted in NB-IoT investigations, enabling more realistic simulations of urban scenarios similar to the sites covered by our measurements.

  • 327.
    Caso, Giuseppe
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Rajiullah, Mohammad
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kousias, Konstantinos
    University of Oslo, Norway.
    Ali, Usman
    Sapienza University of Rome, Italy.
    De Nardis, Luca
    Sapienza University of Rome, Italy.
    Brunstrom, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Alay, Özgü
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). University of Oslo, Norway.
    Neri, Marco
    Rohde and Schwarz, Italy.
    Di Benedetto, Maria-Gabriella
    Sapienza University of Rome, Italy.
    An Initial Look into the Performance Evolution of 5G Non-Standalone Networks2023In: TMA 2023 - Proceedings of the 7th Network Traffic Measurement and Analysis Conference, Institute of Electrical and Electronics Engineers (IEEE), 2023, p. 1-4Conference paper (Refereed)
    Abstract [en]

    Fifth Generation (5G) networks have been operational worldwide for a couple of years. To reveal how the 5G system evolution (e.g., changes in network conditions, deployment, and configurations) affects user performance, empirical long-term analyses are required. This paper presents preliminary insights from our ongoing large-scale measurement study of the commercial 5G non-standalone (NSA) networks deployed in Rome, Italy. An initial comparison between the measurements in 2020-2021 vs. 2023 shows a decrease in throughput and latency performance, calling for deeper analyses toward understanding the root causes and deriving proper optimization solutions. 

  • 328.
    Chahed, Hamza
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Software-Defined Time Sensitive Networks Configuration and Management2021In: 2021 IEEE Conference on Network Function Virtualization and Software Defined Networks: NFV-SDN 2021, Institute of Electrical and Electronics Engineers (IEEE), 2021, p. 124-128Conference paper (Refereed)
    Abstract [en]

    Deterministic real time networking is typically provided by dedicated fieldbus networks which prevents innovation due to their proprietary nature, inflexibility and high-cost. Recently, Time Sensitive Networking (TSN) emerged as a set of Ethernet enhancements, which enables innovation in deterministic networking areas thanks to its openness and capability to serve a variety of traffic types over a converged network infrastructure. However, configuration and management of TSN is difficult due to the complexity of mechanisms that need to be deployed, configured and managed in order to provide real-Time guarantees. Luckily, with recent advancements in the area of software-defined networking (SDN), control plane programmability is simplified, also enabling logically centralized view for network configuration methods. In this paper, we focus on the potential of SDN for the configuration and management of TSN elements. We aim to contribute to an (i) understanding on how SDN can help in the configuration of TSN and (ii) propose a standards compliant TSN network controller, using micro-service architecture for flexibility and scalability. We motivate the potential and discuss the main research questions related to its design.

  • 329.
    Chahed, Hamza
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Deggendorf Institute of Technology, Germany.
    TSN Network Scheduling—Challenges and Approaches2023In: Network, E-ISSN 2673-8732, Vol. 3, no 4, p. 585-624Article in journal (Refereed)
    Abstract [en]

    Time-Sensitive Networking (TSN) is a set of Ethernet standards aimed to improve determinism in packet delivery for converged networks. The main goal is to provide mechanisms that enable low and predictable transmission latency and high availability for demanding applications such as real-time audio/video streaming, automotive, and industrial control. To provide the required guarantees, TSN integrates different traffic shaping mechanisms including 802.1Qbv, 802.1Qch, and 802.1Qcr, allowing for the coexistence of different traffic classes with different priorities on the same network. Achieving the required quality of service (QoS) level needs proper selection and configuration of shaping mechanisms, which is difficult due to the diversity in the requirements of the coexisting streams under the presence of potential end-system-induced jitter. This paper discusses the suitability of the TSN traffic shaping mechanisms for the different traffic types, analyzes the TSN network configuration problem, i.e., finds the optimal path and shaper configurations for all TSN elements in the network to provide the required QoS, discusses the goals, constraints, and challenges of time-aware scheduling, and elaborates on the evaluation criteria of both the network-wide schedules and the scheduling algorithms that derive the configurations to present a common ground for comparison between the different approaches. Finally, we analyze the evolution of the scheduling task, identify shortcomings, and suggest future research directions.

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  • 330.
    Chahed, Hamza
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Usman, Muhammad
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Chatterjee, Ayan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Bayram, Firas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Chaudhary, Rajat
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunstrom, Anna
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Czech Technical University in Prague, Czech Republic.
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Deggendorf Institute of Technology, Germany.
    AIDA—Aholistic AI-driven networking and processing framework for industrial IoT applications2023In: Internet of Things: Engineering Cyber Physical Human Systems, E-ISSN 2542-6605, Vol. 22, article id 100805Article in journal (Refereed)
    Abstract [en]

    Industry 4.0 is characterized by digitalized production facilities, where a large volume of sensors collect a vast amount of data that is used to increase the sustainability of the production by e.g. optimizing process parameters, reducing machine downtime and material waste, and the like. However, making intelligent data-driven decisions under timeliness constraints requires the integration of time-sensitive networks with reliable data ingestion and processing infrastructure with plug-in support of Machine Learning (ML) pipelines. However, such integration is difficult due to the lack of frameworks that flexibly integrate and program the networking and computing infrastructures, while allowing ML pipelines to ingest the collected data and make trustworthy decisions in real time. In this paper, we present AIDA - a novel holistic AI-driven network and processing framework for reliable data-driven real-time industrial IoT applications. AIDA manages and configures Time-Sensitive networks (TSN) to enable real-time data ingestion into an observable AI-powered edge/cloud continuum. Pluggable and trustworthy ML components that make timely decisions for various industrial IoT applications and the infrastructure itself are an intrinsic part of AIDA. We introduce the AIDA architecture, demonstrate the building blocks of our framework and illustrate it with two use cases. 

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  • 331.
    Chatterjee, Ayan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013). Czech Technical University in Prague, Czech Republic.
    IoT anomaly detection methods and applications: A survey2022In: Internet of Things: Engineering Cyber Physical Human Systems, E-ISSN 2542-6605, Vol. 19, article id 100568Article, review/survey (Refereed)
    Abstract [en]

    Ongoing research on anomaly detection for the Internet of Things (IoT) is a rapidly expanding field. This growth necessitates an examination of application trends and current gaps. The vast majority of those publications are in areas such as network and infrastructure security, sensor monitoring, smart home, and smart city applications and are extending into even more sectors. Recent advancements in the field have increased the necessity to study the many IoT anomaly detection applications. This paper begins with a summary of the detection methods and applications, accompanied by a discussion of the categorization of IoT anomaly detection algorithms. We then discuss the current publications to identify distinct application domains, examining papers chosen based on our search criteria. The survey considers 64 papers among recent publications published between January 2019 and July 2021. In recent publications, we observed a shortage of IoT anomaly detection methodologies, for example, when dealing with the integration of systems with various sensors, data and concept drifts, and data augmentation where there is a shortage of Ground Truth data. Finally, we discuss the present such challenges and offer new perspectives where further research is required.

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  • 332.
    Chatterjee, Ayan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Ahmed, Bestoun S.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Hallin, Erik
    Uddeholms AB.
    Engman, Anton
    Uddeholms AB.
    Testing of machine learning models with limited samples: an industrial vacuum pumping application2022In: ESEC/FSE ’22-Proceedings of the 30th ACM Joint Meeting European Software Engineering Conference and Symposium on the Foundations of Software Engineering / [ed] Abhik Roychoudhury, Cristian Cadar, and Miryung Kim, Association for Computing Machinery (ACM), 2022, p. 1280-1290Conference paper (Refereed)
    Abstract [en]

    There is often a scarcity of training data for machine learning (ML) classification and regression models in industrial production, especially for time-consuming or sparsely run manufacturing processes. Traditionally, a majority of the limited ground-truth data is used for training, while a handful of samples are left for testing. In that case, the number of test samples is inadequate to properly evaluate the robustness of the ML models under test (i.e., the system under test) for classification and regression. Furthermore, the output of these ML models may be inaccurate or even fail if the input data differ from the expected. This is the case for ML models used in the Electroslag Remelting (ESR) process in the refined steel industry to predict the pressure in a vacuum chamber. A vacuum pumping event that occurs once a workday generates a few hundred samples in a year of pumping for training and testing. In the absence of adequate training and test samples, this paper first presents a method to generate a fresh set of augmented samples based on vacuum pumping principles. Based on the generated augmented samples, three test scenarios and one test oracle are presented to assess the robustness of an ML model used for production on an industrial scale. Experiments are conducted with real industrial production data obtained from Uddeholms AB steel company. The evaluations indicate that Ensemble and Neural Network are the most robust when trained on augmented data using the proposed testing strategy. The evaluation also demonstrates the proposed method's effectiveness in checking and improving ML algorithms' robustness in such situations. The work improves software testing's state-of-the-art robustness testing in similar settings. Finally, the paper presents an MLOps implementation of the proposed approach for real-time ML model prediction and action on the edge node and automated continuous delivery of ML software from the cloud. 

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  • 333.
    Chaudhary, Rajat
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Aujla, Gagangeet Singh
    Durham University, GBR.
    Kumar, Neeraj
    Thapar Institute of Engineering and Technology, IND.
    Chouhan, Pushpinder Kaur
    British Telecom, GBR.
    A comprehensive survey on software-defined networking for smart communities2022In: International Journal of Communication Systems, ISSN 1074-5351, E-ISSN 1099-1131, article id e5296Article in journal (Refereed)
    Abstract [en]

    The need to provide services closer to the end-user proximity leads to the exchange of a large volume of data generated from the smart devices deployed at different geo-distributed sites. The massive amount of data generated from the smart devices need to be transmitted, analyzed, and processed. This requires seamless data exchanges among geo-separated nodes, which results in a considerable burden on the underlying network infrastructure and can degrade the performance of any implemented solution. Therefore, a dynamic, agile, and programmable network management paradigm is required. To handle the challenges mentioned above, software-defined networking (SDN) gained much attention from academia, researchers, and industrial sectors. Shifting the computational load from forwarding devices to a logically centralized controller is a dream of every network operator who wants to have complete control and global visibility of the network. Also, the concept of network functions virtualization (NFV) in SDN controller is required to increase resource utilization efficiency. Thus, in this paper, a comprehensive survey on SDN for various smart applications is presented. This survey covers the infrastructural details of SDN hardware and OpenFlow switches, controllers, simulation tools, programming languages, open issues, and challenges in SDN implementation with advanced technologies such as 5G and microservices. In addition, the challenges on the control plane and data plane are highlighted in detail, such as fault tolerance, routing, scheduling of flows, and energy consumption on OpenFlow switches. Finally, various open issues and challenges future scope of SDN are discussed and analyzed in the proposal.

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  • 334.
    Chaudhary, Rajat
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kumar, Neeraj
    Thapar Institute of Engineering and Technology, IND; Asia University, TWN; University of Petroleum and Energy Studies, IND.
    SecGreen: Secrecy Ensured Power Optimization Scheme for Software-Defined Connected IoV2023In: IEEE Transactions on Mobile Computing, ISSN 1536-1233, E-ISSN 1558-0660, Vol. 22, no 4, p. 2370-2386Article in journal (Refereed)
    Abstract [en]

    Software-Defined Internet of Vehicles (SD-IoV) is an emerging technology that is being used in modern intelligent transportation systems (ITS). The ultimate goal of SD-IoV is to provide seamless connectivity to the end-users with low latency and high-speed data transfer. However, due to the increase in the density of the connected IoV using an open channel, i.e., the Internet, the foremost challenges of high power consumption and secure data transfer are inevitable in such an environment. An external eavesdropper may intercept the transmitted message to access the legitimate information over the public channel, i.e., the Internet. Most of the solutions reported in the literature to tackle these issues may not be applicable in the SD-IoV environment due to high computation and communication costs. Motivated from this, in this paper, the problems of high power consumption and secure data transfer in SD-IoV are formulated using mixed-integer non-linear programming (MINLP) with associated constraints. To solve the aforementioned problem, we propose a joint power optimization and secrecy ensured scheme known as SecGreen. SecGreen has an efficient energy harvesting algorithm using simultaneous wireless information and power transfer (SWIPT) to maximize the energy efficiency. Moreover, to mitigate various security attacks, a resilient lightweight secrecy association protocol is designed between vehicle and trusted gateway node of SD-IoV so that only trusted vehicles can communicate with each other and with the nearest base stations. The secrecy association protocol uses security primitives such as- physically unclonable function (PUF), one-way hash function, and bitwise exclusive OR (XOR) operations which are suitable for energy-constraint sensors in SD-IoV. The performance of the SecGreen is compared with the existing schemes, Stable & Scalable Link Optimization (SSLO), and Secure & Energy-Efficient Blockchain-enabled (SEEB) respectively. The result shows that when the number of packets across the subchannel increases, the energy consumption increases. Also, the result shows that the proposed scheme attains 22.5% and 20.34% better energy efficiency as compared to SSLO and SEEB schemes, respectively. In addition, the SecGreen scheme achieves 37.48% and 32.15% higher throughput as compared to SSLO and SEEB schemes. The results obtained show the superior performance of the proposed SecGreen scheme in comparison to these existing competitive schemes in the literature.

  • 335.
    Chavez, Karina
    et al.
    Australia.
    Goratti, L
    Italy.
    Rasheed, T.b
    Italy.
    Oljira, Dejene Boru
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Fedrizzi, R.b
    Italy.
    Riggio, R.
    Italy.
    The Evolutionary Role of Communication Technologies in Public Safety Networks2015In: Wireless Public Safety Networks 1: Overview and Challenges, Elsevier, 2015, 1, p. 21-48Chapter in book (Other academic)
    Abstract [en]

    Existing networks for public safety communications are mostly based on systems such as terrestrial trunked radio (TETRA), TETRAPOL and Project 25. These systems are mainly designed to support voice services. However, public safety communication networks are challenged to expand their scope way beyond their original functions toward more sophisticated devices and support new services including packet data communications. Therefore, governments, public safety agencies and research communities are continuously working together and are making significant progresses toward improving public safety communications capabilities. Next-generation mobile technologies are the enablers for meeting the new requirements of the public safety community. Public safety and commercial systems are typically designed and deployed to fulfill different needs and have different requirements, which are directly affecting the quality of service of the communications. The unique and vital nature of public safety affects the technical decisions that are necessary to guarantee connectivity for everyone, anywhere and anytime. For this reason, recent enhancements of the 4G long term evolution (LTE) in the field of public safety communications, such as device-to-device and group communications for mobiles in physical proximity, accrue a great opportunity to bring new services and a high-level of technological innovation to the public safety workers or first responders. We describe and analyze the evolution of public safety communication systems from the technical standpoint providing a complete overview of what is available in the market and a glimpse of future trends. Furthermore, we discuss the challenges to efficiently deploy, operate and interoperate present and future technologies for public safety communication networks and describe how these technologies can help public safety agencies to meet their expectations.

  • 336.
    Cheng, Jun
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Grinnemo, Karl-Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Telco Distributed DC with Transport Protocol Enhancement for 5G Mobile Networks: A Survey2017Report (Other academic)
    Abstract [en]

    Distributed data center hosts telco virtual network functions, mixing workloads that require data transport through transport protocols with either low end-to-end latency or large bandwidth for high throughput, e.g., from tough requirements in 5G use cases. A trend is the use relatively inexpensive, off-the-shelf switches in data center networks, where the dominated transport traffic is TCP traffic. Today’s TCP protocol will not be able to meet such requirements. The transport protocol evolution is driven by transport performance (latency and throughput) and robust enhancements in data centers, which include new transport protocols and protocol extensions such as DCTCP, MPTCP and QUIC protocols and lead to intensive standardization works and contributions to 3GPP and IETF.

    By implementing ECN based congestion control instead of the packet-loss based TCP AIMD congestion control algorithm, DCTCP not only solves the latency issue in TCP congestion control caused by the switch buffer bloating but also achieves an improved performance on the packet loss and throughput. The DCTCP can also co-exist with normal TCP by applying a modern coupled queue management algorithm in the switches of DC networks, which fulfills IETF L4S architecture. MPTCP is an extension to TCP, which can be implemented in DC’s Fat tree architecture to improve transport throughput and shorten the latency by mitigating the bandwidth issue caused by TCP connection collision within the data center. The QUIC is a reliable and multiplexed transport protocol over UDP transport, which includes many of the latest transport improvements and innovation, which can be used to improve the transport performance on streaming media delivery.

    The Clos topology is a commonly used network topology in a distributed data center. In the Clos architecture, an over-provisioned fabric cannot handle full wire-speed traffic, thus there is a need to have a mechanism to handle overload situations, e.g., by scaling out the fabric. However, this will introduce more end-to-end latency in those cases the switch buffer is bloated, and will cause transport flow congestion.

    In this survey paper, DCTCP, MPTCP and QUIC are discussed as solutions for transport performance enhancement for 5G mobile networks to avoid the transport flow congestion caused by the switch buffer bloating from overloaded switch queue in data centers. 

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  • 337.
    Cheng, Jun
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Kovács, Benedek
    Ericsson AB.
    Darula, Marian
    Ericsson AB.
    Proposal for IEC GOOSE transport in 5G networks2018Report (Other academic)
    Abstract [en]

    Smart grid control systems have special latency and performance requirements on the underlying communication network. In 3GPP, such requirements are typically served by the so-called Critical Machine Type Communication (C-MTC) network slice. Generic Object Oriented Substation Events (GOOSE, IEC 61850-8.1) is a protocol used in power substation automation. GOOSE is a layer 2 protocol that operates via multicast over Ethernet which allows Intelligent Electronic Devices (IEDs) to exchange data horizontally between the bays within substation and between the substations, especially for interlocking, measurement and tripping signals. 3GPP 5th generation of mobile networks (5G) will support a variety of services, including Massive Machine-Type Communications (M-MTC) and Ultra-Reliable Low Latency Communications (URLLC) differentiated by the latency and reliability requirements. GOOSE is used by C-MTC in smart grid power substations, which can be a part of URLLC in 5G IoT networks.

    Experiments so far proposed to tunnel GOOSE messages in 4G Evolved Packet Core (EPC) bearers, in an IP tunnel. In this paper, we will motivate the idea of transporting GOOSE over user plane by tunneling via Ethernet over Generic Routing Encapsulation (EoGRE) and 3GPP Non-IP Data Delivery (NIDD), which will follow 3GPP standardization on 5G Standalone (SA), where the transfer latency and reliability will be governed by 5G URLLC. For 5G Non-Standalone (NSA) networks, GOOSE communication involves 5G to Long Term Evolution (LTE) interworking, LTE protocol adaptation from GTP-U/UDP to GRE on S1-U has been realized and deployed in LTE networks. In addition, to reach the right performance level, we propose a GOOSE Gateway (GW) including a 5G Modem to create unicast GOOSE messages to be transmitted over 5G networks. A congestion control algorithm, e.g. Explicit Congestion Notification (ECN), is required in the data link layer (congestion control is supposed to be solved by multicasting in the original Virtual Local Area Network (VLAN) setup). In 3GPP Release 15 standardization, ECN is proposed to be implemented by Low Latency, Low Loss, Scalable Throughput (L4S) congestion control in 5G-NodeB, 5G User Equipment (UE) and other entity. GOOSE messages could share the same ECN congestion control mechanism.

    The main contributions from this paper are: (1) Analyzed and compared GOOSE over Ethernet and GOOSE over IP. (2) Introduced a new logic to optimize GOOSE traffic on EPC user plane via non-IP Packet Data Network (PDN) data type in the 5G network. (3) Suggested to implement GOOSE GW to aggregate and unicasting GOOSE messages effectively between the substations, and to add congestion control by using ECN mechanism in 5G-NodeB and by implementing the pushback/reaction point in GOOSE GW. 

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  • 338.
    Chiaro, Pasquale
    et al.
    InfoCert, Milan, Italy.
    Fischer-Hübner, Simone
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Groß, Thomas
    University of Newcastle upon Tyne, Newcastle upon Tyne, UK.
    Krenn, Stephen
    AIT Austrian Institute of Technology GmbH, Vienna, Austria.
    Lorünser, Tomas
    AIT Austrian Institute of Technology GmbH, Vienna, Austria.
    Garcí, Ana Isabel Martinez
    ETRA Investigacion y Desarrollo, S.A., Valencia, Spain.
    Migliavacca, Andrea
    Lombardia Informatica S.p.A., Milan, Italy.
    Rannenberg, Kai
    Goethe University Frankfurt, Frankfurt, Germany.
    Slamanig, Daniel
    AIT Austrian Institute of Technology GmbH, Vienna, Austria.
    Striecks, Christoph
    AIT Austrian Institute of Technology GmbH, Vienna, Austria.
    Zanini, Alberto
    Lombardia Informatica S.p.A., Milan, Italy.
    Secure and privacy-friendly storage and data processing in the cloud2018In: Privacy and Identity Management. The Smart Revolution / [ed] Marit Hansen, Eleni KostaIgor, Nai-Fovino, Simone Fischer-Hübner, Springer, 2018, p. 153-169Conference paper (Refereed)
    Abstract [en]

    At the IFIP Summer School 2017, the two H2020 projects credential and prismacloud co-organized a workshop dedicated to introducing the necessary background knowledge and demonstrating prototypes of privacy-preserving solutions for storing, sharing, and processing potentially sensitive data in untrusted cloud environments. This paper summarizes the given presentations and presents the discussions and feedback given by the workshop attendees, including students and senior researchers from different domains as well as relevant non-academic stakeholders such as public data protection agencies. © IFIP International Federation for Information Processing 2018.

  • 339.
    Cho, Daewoong
    et al.
    School of Information Technologies, University of Sydney, Sydney, NSW, Australia .
    Bastani, Saeed
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Zomaya, Albert Y
    School of Information Technologies, University of Sydney, Sydney, NSW, Australia .
    Big Data helps SDN to optimize its controllers2018In: Big Data and Software Defined Networks / [ed] Javid Taheri, London: IET Digital Library, 2018, 1, p. 389-408Chapter in book (Refereed)
    Abstract [en]

    In this chapter, we first discuss the basic features and recent issues of the SDN control plane, notably the controller element. Then, we present feasible ideas to address the SDN controller-related problems using Big Data analytics techniques. Accordingly, we propose that Big Data can help various aspects of the SDN controller to address scalability issue and resiliency problem. Furthermore, we proposed six applicable scenarios for optimizing the SDN controller using the Big Data analytics: (i) controller scale-up/out against network traffic concentration, (ii) controller scale-in for reduced energy usage, (iii) backup controller placement for fault tolerance and high availability, (iv) creating backup paths to improve fault tolerance, (v) controller placement for low latency between controllers and switches, and (vi) flow rule aggregation to reduce the SDN controller's traffic. Although real-world practices on optimizing SDN controllers using Big Data are absent in the literature, we expect scenarios we highlighted in this chapter to be highly applicable to optimize the SDN controller in the future.

  • 340.
    Cho, Daewoong
    et al.
    Univ. of Sydney, Sydney, NSW, Australia.
    Taheri, Javid
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Zomaya, Albert Y
    School of Information Technologies, University of Sydney.
    Wang, Lizhe
    China Univ. of Geosci., China.
    Virtual Network Function Placement: Towards Minimizing Network Latency and Lead Time2017In: 2017 IEEE International Conference on Cloud Computing Technology and Science (CloudCom), Piscataway: IEEE, 2017, p. 90-97Conference paper (Refereed)
    Abstract [en]

    Network Function Virtualization (NFV) is an emerging network architecture to increase flexibility and agility within operator's networks by placing virtualized services on demand in Cloud data centers (CDCs). One of the main challenges for the NFV environment is how to minimize network latency in the rapidly changing network environments. Although many researchers have already studied in the field of Virtual Machine (VM) migration and Virtual Network Function (VNF) placement for efficient resource management in CDCs, VNF migration problem for low network latency among VNFs has not been studied yet to the best of our knowledge. To address this issue in this article, we i) formulate the VNF migration problem and ii) develop a novel VNF migration algorithm called VNF Real-time Migration (VNF-RM) for lower network latency in dynamically changing resource availability. As a result of experiments, the effectiveness of our algorithm is demonstrated by reducing network latency by up to 70.90% after latency-aware VNF migrations.

  • 341.
    Chow, Lawrence
    et al.
    Stanford Univ, Stanford, CA 94305 USA.
    Collins, Bradley
    Stanford Univ, Stanford, CA 94305 USA.
    Bambos, Nicholas
    Stanford Univ, Stanford, CA 94305 USA.
    Dely, Peter
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Kassler, Andreas
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Peylo, Christoph
    Deutsch Telekom Labs, Berlin, Germany.
    Einsiedler, Hans
    Deutsch Telekom Labs, Berlin, Germany.
    Bayer, Nico
    Deutsch Telekom Labs, Berlin, Germany.
    Channel Aware Rebuffering for Wireless Media Streaming with Handoff Control2013In: 2013 IEEE GLOBAL COMMUNICATIONS CONFERENCE (GLOBECOM), IEEE Press, 2013, p. 4434-4439Conference paper (Refereed)
    Abstract [en]

    Packet/frame 'rebuffering' in wireless video streaming typically considers only connectivity from the mobile terminal to its network access point (AP). However, in the presence of multiple APs with the possibility of handoffs, the overall wireless environment should be considered. We develop a model capturing joint rebuffering & handoff dynamics in wireless video streaming, and design a new channel-aware joint rebuffering & handoff control scheme, aiming to minimize the long-run average cost of video jitters and freezes. We first characterize the optimal control in the general case of multiple wireless APs/channels and multiple states per channel. Subsequently, we evaluate the system performance in key important cases, using experimental traces of wireless channel data. We explore the relationship between optimal rebuffering thresholds and overall channel dynamics, and evaluate the associated joint handoff control. The performance results demonstrate the importance of jointly managing rebuffering and handoff controls to achieve high-performance wireless video streaming.

  • 342.
    Christian, Larsson
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Utredande undersökning av NoSQL grafdatabaser: En utredande undersökning av OrientDB, ArangoDB och HypergraphDBför ett specifikt användningsfall2019Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The need to store large quantities of data is increasing more and more. In correlation to this the development of various kinds of databases, especially so-called ”NoSQL”-databases, is also increasing. It can be difficult to navigate in this plethora of database solutions to find the the database that best suits a specific project. This report attempts to investigate which of the databases OrientDB, ArangoDB and HypergraphDB is best suited for a specific use case where data is to be saved to represent a building structure. The criteria for the investigation are how the organization behind the database looks, how their datamodels looks, which price models they offer as well as an emperical study of the databases’ performance in the specific use case. This survey is not designed to be a general comparison, but is commissioned by a company to see which database would suit their specific project best. The investigation shows that it’s a complex task to do fair comparisons on performance between NoSQL databases but based on the criteria in this report OrientDB would be best suited for the specific use case.

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  • 343.
    Christin, Delphine
    et al.
    Tech Univ Darmstadt, Secure Mobile Networking Lab, Darmstadt, Germany.
    Roßkopf, Christian
    Tech Univ Darmstadt, Secure Mobile Networking Lab, Darmstadt, Germany.
    Hollick, Matthias
    Tech Univ Darmstadt, Secure Mobile Networking Lab, Darmstadt, Germany.
    Martucci, Leonardo
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Kanhere, Salil
    IncogniSense: An anonymity-preserving reputation frameworkfor participatory sensing applications2012In: Proceedings of the 10th Annual IEEE In-ternational Conference on Pervasive Computing and Communications (PerCom2012) / [ed] Silvia Giordano, Marc Langheinrich, and Albrecht Schmidt, IEEE, 2012, p. 135-143Conference paper (Refereed)
    Abstract [en]

    Reputation systems rate the contributions to participatory sensing campaigns from each user by associatinga reputation score. The reputation scores are used to weedout incorrect sensor readings. However, an adversary can de-anonmyize the users even when they use pseudonyms by linking the reputation scores associated with multiple contributions. Since the contributed readings are usually annotated with spatio-temporal information, this poses a serious breach of privacy for the users. In this paper, we address this privacy threat by proposing a framework called IncogniSense. Our system utilizes periodic pseudonyms generated using blind signature and relies on reputation transfer between these pseudonyms. The reputation transfer process has an inherent trade-off between anonymity protection and loss in reputation. We investigate by means of extensive simulations several reputation cloaking schemes that address this tradeoff differently. Our system is robust against reputation corruption and a proof-of-concept implementation demonstrates that the associated overheads are minimal.

  • 344. Christoforidis, Christos
    et al.
    Ivarsson, Niklas
    Johansson, Henrik
    Nilsson, Jonas
    Grinnemo, Karl-Johan
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    SCTPTrace: An Extension of TCPTrace for SCTP2016Report (Other (popular science, discussion, etc.))
    Abstract [en]

    When it comes to analyzing TCP data and extracting the information in such a way that it becomes viewable, there are a couple of tools that can be used. One of them is TCPTrace. TCPTrace is used to analyze special dump files created from programs such as tcpdump, snoop and WinDump. TCPTrace became published for a broader public in the late 1996 by Shawn Ostermann. Since then functionalities, changes and fixes have been implemented for example the extension to create graphs and trace UDP packets. From the dump files a trace will be done, and depending on the input from the user, TCPTrace can present this information in a number of ways such as plain text, trace files and graphs, depending on the amount of information the user is looking for. The extensive information traced will be viewed and divided for each connection found. For each connection, information such as retransmits, throughput, round trip times, bytes and packets sent and received etc. can be presented.

    This project came to be, since there has been a desire to see a tool for SCTP that provides the same functionalities as TCPTrace. The project, called SCTPTrace, aimed to implement as much of the previous TCP functionalities as possible for the SCTP protocol. 

  • 345.
    Ciallellla, Alessandro
    et al.
    Sapienza Univ Roma, Dipartimento Sci Base & Applicate Ingn, Rome, Italy.
    Cirillo, Emilio
    Sapienza Univ Roma, Dipartimento Sci Base & Applicate Ingn, Rome, Italy.
    Curseu, Petre
    Babes Bolyai Univ, Dept Psychol, Cluj, Romania Open Univ Netherlands, Dept Org, Heerlen, Netherlands.
    Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Free to move or trapped in your group: Mathematical modeling of information overload and coordination in crowded populations2018In: Mathematical Models and Methods in Applied Sciences, ISSN 0218-2025, Vol. 28, no 9, p. 1831-1856Article in journal (Refereed)
    Abstract [en]

    We present modeling strategies that describe the motion and interaction of groups of pedestrians in obscured spaces. We start off with an approach based on balance equations in terms of measures and then we exploit the descriptive power of a probabilistic cellular automaton model. Based on a variation of the simple symmetric random walk on the square lattice, we test the interplay between population size and an interpersonal attraction parameter for the evacuation of confined and darkened spaces. We argue that information overload and coordination costs associated with information processing in small groups are two key processes that influence the evacuation rate. Our results show that substantial computational resources are necessary to compensate for incomplete information - the more individuals in (information processing) groups the higher the exit rate for low population size. For simple social systems, it is likely that the individual representations are not redundant and large group sizes ensure that this non-redundant information is actually available to a substantial number of individuals. For complex social systems, information redundancy makes information evaluation and transfer inefficient and, as such, group size becomes a drawback rather than a benefit. The effect of group sizes on outgoing fluxes, evacuation times and wall effects is carefully studied with a Monte Carlo framework accounting also for the presence of an internal obstacle.

  • 346.
    Cider, Andreas
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Jacobs, Max
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Byggserverövervakning: Utveckling av ett system för att synliggöra integrationsproblem2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Software in computers control many important functions in today's society and are widely used for communication but also to control equipment. For the software to work reliably it needs to be built correctly and tested extensively. To achieve reliability, a build server can be used to automatically build and test the software. This report describes how a prototype of a monitoring system for the build servers was created. The system will be monitored by a monitoring service that retrieves information from a build server using the CruiseControl.NET [10] software. The information gathered by the monitoring service will be presented on a web portal. The information retrieved from build the server goes from a high level of abstraction down to the smallest detail that is based on the log files from the build server, for example, information about compilation errors.

    The development of the monitoring system has been focused on making it possible to use cloud services and thus not restrict where a build server is located. One of the cloud services used is the Service Bus Relay [27] that handles the communication between a monitoring service and the web portal. The web portal is developed to be responsive [34] and provide support for mobile devices which give the user the freedom to visit the web portal from whatever device. The web portal uses a database to store information which enables monitoring of multiple build servers. A well-developed user management system is used on the web portal which provides administrators with an effective tool for user management. There have been several lessons learned, including the discovery of a bug in the Microsoft implementation of message handling in the Service Bus Relay.

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    Byggserverövervakning
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    Arkivfil
  • 347.
    Cirillo, E. N. M.
    et al.
    Sapienza University Roma, ITA.
    de Bonis, I.
    University Giustino Fortunato, ITA.
    Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Richardson, Omar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Upscaling the interplay between diffusion and polynomial drifts through  a composite thin strip with periodic microstructure2020In: Meccanica (Milano. Print), ISSN 0025-6455, E-ISSN 1572-9648, Vol. 55, no 11, p. 2159-2179Article in journal (Refereed)
    Abstract [en]

    We study the upscaling of a system of many interacting particles through a heterogenous thin elongated obstacle as modeled via a two-dimensional diffusion problem with a one-directional nonlinear convective drift. Assuming that the obstacle can be described well by a thin composite strip with periodically placed microstructures, we aim at deriving the upscaled model equations as well as the effective transport coefficients for suitable scalings in terms of both the inherent thickness at the strip and the typical length scales of the microscopic heterogeneities. Aiming at computable scenarios, we consider that the heterogeneity of the strip is made of an array of periodically arranged impenetrable solid rectangles and identify two scaling regimes what concerns the small asymptotics parameter for the upscaling procedure: the characteristic size of the microstructure is either significantly smaller than the thickness of the thin obstacle or it is of the same order of magnitude. We scale up the diffusion-polynomial drift model and list computable formulas for the effective diffusion and drift tensorial coefficients for both scaling regimes. Our upscaling procedure combines ideas of two-scale asymptotics homogenization with dimension reduction arguments. Consequences of these results for the construction of more general transmission boundary conditions are discussed. We illustrate numerically the concentration profile of the chemical species passing through the upscaled strip in the finite thickness regime and point out that trapping of concentration inside the strip is likely to occur in at least two conceptually different transport situations: (i) full diffusion/dispersion matrix and nonlinear horizontal drift, and (ii) diagonal diffusion matrix and oblique nonlinear drift.

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  • 348.
    Cirillo, Emilio
    et al.
    Sapienza University, Italy.
    Colangeli, Matteo
    University of L’Aquila, Italy.
    Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Thieu, T. K. Thoa
    Gran Sasso Science Institute, Italy.
    A lattice model for active–passive pedestrian dynamics: a quest for drafting effects2020In: Mathematical Biosciences and Engineering, ISSN 1547-1063, E-ISSN 1551-0018, Vol. 17, no 1, p. 460-477Article in journal (Refereed)
    Abstract [en]

    We study the pedestrian escape from an obscure room using a lattice gas model with twospecies of particles. One species, called passive, performs a symmetric random walk on the lattice,whereas the second species, called active, is subject to a drift guiding the particles towards the exit.The drift mimics the awareness of some pedestrians of the geometry of the room and of the location ofthe exit. We provide numerical evidence that, in spite of the hard core interaction between particles –namely, there can be at most one particle of any species per site – adding a fraction of active particlesin the system enhances the evacuation rate of all particles from the room. A similar effect is alsoobserved when looking at the outgoing particle flux, when the system is in contact with an externalparticle reservoir that induces the onset of a steady state. We interpret this phenomenon as a discretespace counterpart of the drafting effect typically observed in a continuum set–up as the aerodynamicdrag experienced by pelotons of competing cyclists.

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  • 349.
    Cirillo, Emilio
    et al.
    Sapienza Università di Roma, ITA.
    Colangeli, Matteo
    Università Degli Studi dell'Aquila, ITA.
    Richardson, Omar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Rondoni, Lamberto
    Politecnico di Torino, ITA; INFN, ITA.
    Deterministic model of battery, uphill currents and non-equilibrium phase transitions2021In: Physical Review E. Statistical, Nonlinear, and Soft Matter Physics: Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics, ISSN 1063-651X, E-ISSN 1095-3787, Vol. 103, no 3Article in journal (Refereed)
    Abstract [en]

    We consider point particles in a table made of two circular cavities connected by two rectangular channels, forming a closed loop under periodic boundary conditions. In the first channel, a bounce-back mechanism acts when the number of particles flowing in one direction exceeds a given threshold T. In that case, the particles invert their horizontal velocity, as if colliding with vertical walls. The second channel is divided in two halves parallel to the first but located in the opposite sides of the cavities. In the second channel, motion is free. We show that, suitably tuning the sizes of cavities of the channels and of T, nonequilibrium phase transitions take place in the N→∞ limit. This induces a stationary current in the circuit, thus modeling a kind of battery, although our model is deterministic, conservative, and time reversal invariant.

  • 350.
    Cirillo, Emilio
    et al.
    Sapienza Univ Roma, Dipartimento Sci Base & Appl Ingn, Via A Scarpa 16, I-00161 Rome, Italy.
    Krehel, Oleh
    Eindhoven Univ Technol, ICMS, Dept Math & Comp Sci, POB 513, NL-5600 MB Eindhoven, Netherlands.
    Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    van Santen, Rutger
    Eindhoven Univ Technol, Fac Chem Engn, ICMS, POB 513, NL-5600 MB Eindhoven, Netherlands.
    Lattice model of reduced jamming by a barrier2016In: Physical review. E, ISSN 2470-0045, E-ISSN 2470-0053, Vol. 94, no 4, article id 042115Article in journal (Refereed)
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