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  • 551.
    Magnusson, Anton
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Larsson, Jan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Implementation of TeliaSonera Incident Management Centre Site Attendance Application2013Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    TeliaSonera Incident Management Centre Karlstad has been situated in facilities placed in the bedrock of the Kroppkärr district of Karlstad for over ten years. From here TeliaSonera monitors parts of their different kind of networks all over the globe. One part is the monitoring of sites, a structure that holds equipment vital for a network to function.

    Currently TeliaSonera Incident Management Centre receives about thirty phone calls a dayfrom technicians from all over the world regarding the reporting of attendance on sites. Themain objective is to create a mobile application that can substitute the need of a phone call.

    The project resulted in the development of two web applications, one application with the purpose to replace the site attendance reporting by phone and another to monitor the incoming reports. The reason for developing a web application was to deliver a platform independentproduct under a short period of time. The site reporting application is resistant to attacks suchas SQL-injections and Cross-Site Scripting.

    Functionality of web applications is closing in on the functionality behind native applications. Features included in HTML5 allow the developer to take more liberty when programming web applications. These features are utilized in the search and filter functions of the monitoring application in this project. The applications are written in HTML5, JavaScript and PHP and the data is stored in a MySQL database.

  • 552.
    Magnusson, Jonathan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Designing DNS Cache Aggregation to Detect Misbehaving Certificate Transparency Logs2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
  • 553.
    Magnusson, Ulf
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A tool for visual analysis of permission-based data access on Android phones2019Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Privacy is a topic of ever-increasing interest in the modern, connected world. With the advent of smart phones, the boundary between internet and the personal sphere has become less distinct. Most users of smart phones have very vague ideas of how various apps intrude on their privacy.

    At Karlstad University, one of the research groups at the Department of Computer Science is dedicated to research on privacy and protection thereof in general, and one research project is about increasing knowledge of how apps collect personal information about its users.

    This master thesis is about the development of a visualization tool that processes data collected from Android devices by a surveillance app developed within the aforementioned research project. The app keeps record of the usage of what in Android is termed Dangerous Permissions. The info collected is when such an event occurs, which app has requested the permission, the permission requested as well as the geographical location at the time of the event. Over time, more than 2 million such events has been recorded and collected in this manner.

    Previously, two student projects have developed different web based tools for visualizing the data collected. With this thesis work, a desktop application was developed; a visualization tool that imports the aforementioned data into a database connected to the tool. The graphical user interface of the visualization tool allows an analyst or scientific researcher to do detailed and fine-grained searches in that database and present the result in various charts, thereby visualizing how the apps ask for information that can be used for identifying and surveying individuals, thereby intruding on their privacy.

    The visualization tool is carefully designed with the aim for it to be scalable and extendable, through an architecture that allows for continuous development of further visualizations as well as other analysis functionality.

  • 554.
    Mahmoud, Thair Shakir
    et al.
    Edith Cowan University, Australia.
    Ahmed, Bestoun S.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Czech Technical University, Czech Republic.
    Hassan, Mohammed Y.
    University of Technology, Iraq.
    The role of intelligent generation control algorithms in optimizing battery energy storage systems size in microgrids: A case study from Western Australia2019Inngår i: Energy Conversion and Management, ISSN 0196-8904, E-ISSN 1879-2227, Vol. 196, s. 1335-1352Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Battery energy storage systems can play a substantial role in maintaining low-cost operation in microgrids, and therefore finding their optimal size is a key element of microgrids’ planning and design. This paper explores the optimal sizing options for batteries in microgrids that include wind turbines, solar photovoltaics, synchronous machines and a grid connection supply under various types of retail tariff schemes. The optimal size of batteries is hypothesized to be significantly related to the intelligent control rules applied to dispatch the microgrid sources. This problem can be formulated as a mixed linear integer problem and can be solved using linear/non-linear solvers depending on the complexity of the generation control plan. The main objective of this work is to apply online intelligent adaptation mechanism to tune the economic generation control (dispatch) rules of the microgrid. This tuning objectives are maintaining secure operation, maximizing profitable utilization of batteries and managing their charging life-cycles. While sizing options exploration has been formulated as a linear programming based optimization problem, Fuzzy-Logic is proposed to control the charging/discharging time and quantity for batteries. For the sake of performance comparison, various optimization techniques, i.e., Particle Swarm Optimization, Genetic Algorithm and Flower Pollination Algorithm are applied to perform the economic dispatch calculation. As a case study, a commercial type load connected to the 22 kV distribution network in south Western Australia was used in the testing and validation if the results of the proposed sizing method. The operation condition data was obtained from Western Power the distribution and transmission company in south Western Australia, the Australian Bureau Of Meteorology (BOM) and the Australian Energy Market Operator (AEMO). The results showed that employing intelligent batteries in operation can reduce the annual generation cost of microgrids. However, the decision on selecting the size of batteries depends heavily on the amount of upfront investment cost. The simulation results showed that the intelligence added to batteries’ control could achieve 6.5%, 7.6% and 11.5% of the annual generation cost in the Islanded, Grid-connected with no-export and Grid-connected with export operating modes respectively. Also, intelligent batteries operation control was proven to minimize their payback time to 2.8, 2.7 and 2.7 years in the Islanded, Grid-connected with no-export and Grid-connected with export operating modes respectively.

  • 555.
    Malmstedt, Josefin
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Digitala verktyg i matematikundervisningen: En kvalitativ studie om lågstadielärares tillgång till, och uppfattning om, digitala verktyg2017Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    Digital technology is to be found in many places today, especially in school. The purpose of this study was to examine the use of digital tools in the teaching of mathematics by lower secondary teachers. The method of the study was a qualitative method in which eight teachers from tree different schools were interviewed. The material collected from the interviews was analyzed on the basis of a content analysis, where the results were divided into two main categories and then into subcategories. The two main categories that emerged were "Digital tools in teaching" and "Teachers´ perception of digital tools". The earlier research indicated that the teachers´skills had great influence in how they choose to use the digital tools. Research also showed that digital tools, if used for the right purpose, could affect student motivation and mathematical understanding in a positive way. The result of the study shows that all the teachers that participated see digital tools as something positive even though they themselves think that they should have had more digital skills. They however see a profit with digital tools and believe that students become more committed when they use them. They also think that digital tools are important in order to make a difference in their teaching. What emerges from the result is that digital tools in teaching have a good effect on students´ motivation but that teachers´ digital skills need to be improved. The government´s decision to clarify the curriculum in terms of digital competence also places higher demands on teachers. 

  • 556. Mamedov, F
    et al.
    Mammadzade, N
    Persson, Lars-Erik
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A new fractional order Poincare¨s inequalitywith weightsInngår i: Mathematical Inequalities & Applications, ISSN 1331-4343, E-ISSN 1848-9966Artikkel i tidsskrift (Fagfellevurdert)
  • 557.
    Mancuso, Vincenzo
    et al.
    IMDEA Networks Institute, Spain.
    Peón Quirós, Miguel
    IMDEA Networks Institute, Spain; Ecole Polytech Fed Lausanne, Switzerland.
    Midoglu, Cise
    Simula Res Lab, Norway.
    Moulay, Mohamed
    IMDEA Networks Inst, Spain; University Carlos III of Madrid, Spain.
    Comite, Vincenzo
    IMDEA Networks Inst, Spain; University La Sapienza, Italy.
    Lutu, Andra
    Simula Res Lab, Norway.
    Alay, Ozgu
    Simula Res Lab, Norway.
    Alfredsson, Stefan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Rajiullah, Mohammad
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Mellia, Marco
    Politecnico di Torino, Italy.
    Khatouni, Ali Safari
    Politecnico di Torino, Italy.
    Hirsch, Thomas
    Celerway, Norway.
    Results from running an experiment as a service platform for mobile broadband networks in Europe2019Inngår i: Computer Communications, ISSN 0140-3664, E-ISSN 1873-703X, Vol. 33, s. 89-101Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this article we present a selection from a vast range of experiments run with MONROE, our open experiment as a service (EaaS) platform for measurements and experimentation in Mobile Broadband Networks. We show that the platform can be used to benchmark network performance in a repeatable and controlled manner thanks to the collection of a rich set of geotagged metadata and the execution of discretionary user experiments. Indeed, with the sheer amount of data collected from 12 commercial mobile operators across Europe, MONROE offers an unprecedented opportunity to monitor, analyze and ultimately improve the status of current and future mobile broadband networks. Besides, we show how flexibly the platform allows combining metadata and experimental data series during the experiments or by means of post-processing, and show results produced by our own experiments as well as comment on results obtained by external research groups and developers that have been granted access to our platform.

  • 558.
    Mandalari, Anna Maria
    et al.
    University Carlos III of Madrid, Spain.
    Lutu, Andra
    Telefonica Research, Spain.
    Custura, Ana
    University of Aberdeen, Scotland.
    Khatouni, Ali Safari
    Politecnico di Torino, Italy.
    Alay, Özgü
    Simula Metropolitan, Norway.
    Bajpai,, Vaibhav
    Technische Universität München, Germany.
    Brunström, Anna
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Ott, Jörg
    Technische Universität München, Germany.
    Mellia, Marco
    Politecnico di Torino, Italy.
    Fairhust, Gorry
    University of Aberdeen, Scotland.
    Experience: Implications of Roaming in Europe2018Inngår i: MobiCom '18. Proceedings of the 24th Annual International Conference on Mobile Computing and Networking / [ed] Rajeev Shorey, Rohan Murty, New York, USA: ACM Publications, 2018, s. 179-189Konferansepaper (Fagfellevurdert)
    Abstract [en]

    "Roam like Home" is the initiative of the European Commission (EC) to end the levy of extra charges when roaming within the European region. As a result, people are able to use data services more freely across Europe. However, the implications roaming solutions have on performance have not been carefully examined. This paper provides an in-depth characterization of the implications of international data roaming within Europe. We build a unique roaming measurement platform using 16 different mobile networks deployed in six countries across Europe. Using this platform, we measure different aspects of international roaming in 3G and 4G networks, including mobile network configuration, performance characteristics, and content discrimination. We find that operators adopt common approaches to implementing roaming, resulting in additional latency penalties of ∼60 ms or more, depending on geographical distance. Considering content accessibility, roaming poses additional constraints that leads to only minimal deviations when accessing content in the original country. However, geographical restrictions in the visited country make the picture more complicated and less intuitive.

  • 559. Marky, Karola
    et al.
    Gutmann, Andreas
    Rack, Philipp
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Privacy Friendly Apps-Making Developers Aware of Privacy Violations2016Inngår i: IMPS 2016Innovations in Mobile Privacy and Security: Proceedings of the 1st International Workshop on Innovations in Mobile Privacy and Security co-located with the International Symposium on Engineering Secure Software and Systems (ESSoS 2016), CEUR , 2016, Vol. 1, s. 46-48Konferansepaper (Fagfellevurdert)
  • 560.
    Marotta, Antonio
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). University of Naples Federico II.
    Avallone, Stefano
    University of Naples Federico II.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    A Joint Power Efficient Server and Network Consolidation approach for virtualized data centers2018Inngår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 130, s. 65-80Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Cloud computing and virtualization are enabling technologies for designing energy-aware resource management mechanisms in virtualized data centers. Indeed, one of the main challenges of big data centers is to decrease the power consumption, both to cut costs and to reduce the environmental impact. To this extent, Virtual Machine (VM) consolidation is often used to smartly reallocate the VMs with the objective of reducing the power consumption, by exploiting the VM live migration. The consolidation problem consists in finding the set of migrations that allow to keep turned on the minimum number of servers needed to host all the VMs. However, most of the proposed consolidation approaches do not consider the network related consumption, which represents about 10–20% of the total energy consumed by IT equipment in real data centers. This paper proposes a novel joint server and network consolidation model that takes into account the power efficiency of both the switches forwarding the traffic and the servers hosting the VMs. It powers down switch ports and routes traffic along the most energy efficient path towards the least energy consuming server under QoS constraints. Since the model is complex, a fast Simulated Annealing based Resource Consolidation algorithm (SARC) is proposed. Our numerical results demonstrate that our approach is able to save on average 50% of the network related power consumption compared to a network unaware consolidation.

  • 561.
    Marotta, Antonio
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    D’Andreagiovanni, Fabio
    Sorbonne Universités, Université de Technologie de Compiègne, France.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Zola, Enrica
    Universitat Politècnica de Catalunya, C. Barcelona, Spain.
    On the energy cost of robustness for green virtual network function placement in 5G virtualized infrastructures2017Inngår i: Computer Networks, ISSN 1389-1286, E-ISSN 1872-7069, Vol. 125, s. 64-75Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Next generation 5G networks will rely on virtualized Data Centers (vDC) to host virtualized network functions on commodity servers. Such Network Function Virtualization (NFV) will lead to significant savings in terms of infrastructure cost and reduced management complexity. However, green strategies for networking and computing inside data centers, such as server consolidation or energy aware routing, should not negatively impact the quality and service level agreements expected from network operators. In this paper, we study how robust strategies that place virtual network functions (VNF) inside vDC impact the energy savings and the protection level against resource demand uncertainty. We propose novel optimization models that allow the minimization of the energy of the computing and network infrastructure which is hosting a set of service chains that implement the VNFs. The model explicitly provides for robustness to unknown or imprecisely formulated resource demand variations, powers down unused routers, switch ports and servers, and calculates the energy optimal VNF placement and network embedding also considering latency constraints on the service chains. We propose both exact and heuristic methods. Our experiments were carried out using the virtualized Evolved Packet Core (vEPC), which allows us to quantitatively assess the trade-off between energy cost, robustness and the protection level of the solutions against demand uncertainty. Our heuristic is able to converge to a good solution in a very short time, in comparison to the exact solver, which is not able to output better results in a longer run as demonstrated by our numerical evaluation. We also study the degree of robustness of a solution for a given protection level and the cost of additional energy needed because of the usage of more computing and network elements.

  • 562.
    Marotta, Antonio
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A Power Efficient and Robust Virtual Network Functions Placement Problem2016Inngår i: Teletraffic Congress (ITC 28), 2016 28th International, IEEE, 2016Konferansepaper (Fagfellevurdert)
  • 563.
    Marotta, Antonio
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap. Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Green Virtual Network Functions Placement Under Uncertainty Constraints2016Inngår i: , 2016Konferansepaper (Fagfellevurdert)
  • 564.
    Marotta, Antonio
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Zola, Enrica
    Universitat Politècnica de Catalunya, Barcelona, Spain.
    D'Andreagiovanni, Fabio
    Sorbonne Universités, Université de Technologie de Compiègne, France.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Centrum för HumanIT.
    A fast robust optimization-based heuristic for the deployment of green virtual network functions2017Inngår i: Journal of Network and Computer Applications, ISSN 1084-8045, E-ISSN 1095-8592, Vol. 95, s. 45-53Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Network Function Virtualization (NFV) has attracted a lot of attention in the telecommunication field because it allows to virtualize core-business network functions on top of a NFV Infrastructure. Typically, virtual network functions (VNFs) can be represented as chains of Virtual Machines (VMs) or containers that exchange network traffic which are deployed inside datacenters on commodity hardware. In order to achieve cost efficiency, network operators aim at minimizing the power consumption of their NFV infrastructure. This can be achieved by using the minimum set of physical servers and networking equipment that are able to provide the quality of service required by the virtual functions in terms of computing, memory, disk and network related parameters. However, it is very difficult to predict precisely the resource demands required by the VNFs to execute their tasks. In this work, we apply the theory of robust optimization to deal with such parameter uncertainty. We model the problem of robust VNF placement and network embedding under resource demand uncertainty and network latency constraints using robust mixed integer optimization techniques. For online optimization, we develop fast solution heuristics. By using the virtualized Evolved Packet Core as use case, we perform a comprehensive evaluation in terms of performance, solution time and complexity and show that our heuristic can calculate robust solutions for large instances under one second.

  • 565.
    Martucci, Leonardo
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Fischer-Hübner, Simone
    Karlstads universitet, Institutionen för informationsteknologi.
    Jirotka, Marina
    Privacy and Social Values in Smart Cities2016Inngår i: Designing, Developing, and Facilitating Smart Cities: Urban Design to IoT Solutions / [ed] Angelakis, Tragos, Kapovits, Pöhls, and Bassi, Heidelberg: Springer, 2016Kapittel i bok, del av antologi (Fagfellevurdert)
  • 566.
    Martucci, Leonardo
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Ries, Sebastian
    Mühlhäuser, Max
    Technische Universität Darmstadt.
    Identifiers, Privacy and Trust in the Internet of Services2010Inngår i: Short Paper Proceedings of the 4th IFIP WG 11.11 International Conference on Trust Management (IFIPTM 2010), 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents a solution for the problem of merging privacy-friendly identifiers with trust information without support or assistance from central authorities during the operation phase. Trust information is dynamic and associated to the pseudonyms. Our solution is constructed using role-based pseudonyms that are associated to an arbitrary number of different contexts. Moreover, the presented scheme provides inherent detection and mitigation of Sybil attacks. Finally, we present an attacker model and evaluate the security and privacy properties and robustness of our solution

  • 567.
    Martucci, Leonardo
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Zuccato, Albin
    TeliaSonera, Stockholm, Sweden.
    Smeets, Ben
    Ericsson Res., Lund, Sweden.
    Habib, Sheikh M.
    Tech. Univ. Darmstadt, Darmstadt, Germany.
    Johansson, Thomas
    Lund Univ., Lund, Sweden.
    Shahmehri, Nahid
    Univ. of Linkoping, Linkoping, Sweden.
    Privacy, security and trust in cloud computing: The perspective of the telecommunication industry2012Inngår i: UIC/ATC: 9th International Conference on Ubiquitous Intelligence and Computing and 9th International Conference on Autonomic and Trusted Computing, UIC/ATC 2012, Fukuoka, Japan, September 4-7, 2012, IEEE, 2012, s. 627-632Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The telecommunication industry has been successfulin turning the Internet into a mobile service and stimulating the creation of a new set of networked, remote services. In this paper we argue that embracing cloud computing solutions is fundamental for the telecommunication industry to remain competitive. However, there are legal, regulatory, business, marketrelated and technical challenges that must be considered. In this paper we list such challenges and define a set of privacy, security and trust requirements that must be taken into account before cloud computing solutions can be fully integrated and deployed by telecommunication providers.

  • 568. Maseberg, Sönke
    et al.
    Bodden, Eric
    Kus, Mehmet
    Brucker, Achim
    Rasthofer, Siegfried
    Berger, Bernhard
    Huber, Stephan
    Sohr, Karsten
    Gerber, Paul
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Zertifizierte Apps2015Inngår i: Risiken kennen, Herausforderungen annehmen, Lösungen gestalten: Tagungsband zum 14. Deutscher IT-Sicherheitskongress des BSI 2015, SecuMedia , 2015, s. 505-516Konferansepaper (Fagfellevurdert)
  • 569.
    Matsson, Carl Philip
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Securing Microsoft Azure: Automatic Access Control List Rule Generation to Secure Microsoft Azure Cloud Networks2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
  • 570.
    Matsson, Carl Philip
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Kaewprathum, Thodsapon
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Larsson, Adam
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Grinnemo, Karl-Johan
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A Traffic Generator for NEAT2016Rapport (Annet vitenskapelig)
    Abstract [en]

    Ossication is one of the most serious problem facing the future of the Internet. The most commonly used protocols today can not keep up with the increasing demand for better network performance of the next generation of applications. New transport protocols have a hard time replacing the outdated ones. Even well-know protocols such as SCTP and DCCP have failed to become anything but niche protocols on the Internet. To solve this problem a new transport system, NEAT, is currently under development.

    There is limited opportunities to evaluate NEAT in practice. Before this project, there was no trac generator that supports NEAT which would help with evaluation during the development process. This project implements the NEAT transport system onto D-ITG, an existing open source trac generator. D-ITG has many features that can be of use when evaluating NEAT, such as advanced logging and simulation of many dierent applications trac signatures.

  • 571.
    Matsui, Kazunori
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Asymptotic analysis of an ε-Stokes problem with Dirichlet boundary conditions2019Independent thesis Basic level (degree of Bachelor), 10 poäng / 15 hpOppgave
    Abstract [en]

    In this thesis, we propose an ε-Stokes problem connecting the Stokes problem and the corresponding pressure-Poisson equation using one pa- rameter ε > 0. We prove that the solution to the ε-Stokes problem, converges as ε tends to 0 or ∞ to the Stokes and pressure-Poisson prob- lem, respectively. Most of these results are new. The precise statements of the new results are given in Proposition 3.5, Theorem 4.1, Theorem 5.2, and Theorem 5.3. Numerical results illustrating our mathematical results are also presented.

  • 572. Matsui, Kazunori
    et al.
    Muntean, Adrian
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Asymptotic analysis of an ε-Stokes problem connecting Stokes and pressure-Poisson problems2018Inngår i: Advances in Mathematical Sciences and Applications, ISSN 1343-4373, Vol. 27, nr 1, s. 181-191Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    In this Note, we prepare an ε-Stokes problem connecting the Stokes problem and the corresponding pressure-Poisson equation using one parameter ε > 0. We prove that the solution to the ε-Stokes problem, convergences as ε tends to 0 or ∞ to the Stokes and pressure-Poisson problem, respectively.

  • 573.
    Mayer, Peter
    et al.
    Faculty of Computer Sciences, Technische Universitat Darmstadt, Darmstadt, Hessen, Germany.
    Gerber, Nina
    Faculty of Human Sciences, Technische Universitat Darmstadt, Darmstadt, Hessen, Germany.
    McDermott, Ronja
    Faculty of Human Sciences, Technische Universitat Darmstadt, Darmstadt, Hessen, Germany.
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Vogt, Joachim
    Faculty of Human Sciences Technische, Universitat Darmstadt, Darmstadt, Hessen, Germany.
    Productivity vs security: mitigating conflicting goals in organizations2017Inngår i: Information and Computer Security, E-ISSN 2056-4961, Vol. 25, nr 2, s. 137-151Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Purpose

    This paper aims to contribute to the understanding of goal setting in organizations, especially regarding the mitigation of conflicting productivity and security goals.

    Design/methodology/approach

    This paper describes the results of a survey with 200 German employees regarding the effects of goal setting on employees’ security compliance. Based on the survey results, a concept for setting information security goals in organizations building on actionable behavioral recommendations from information security awareness materials is developed. This concept was evaluated in three small- to medium-sized organizations (SMEs) with overall 90 employees.

    Findings

    The survey results revealed that the presence of rewards for productivity goal achievement is strongly associated with a decrease in security compliance. The evaluation of the goal setting concept indicates that setting their own information security goals is welcomed by employees.

    Research limitations/implications

    Both studies rely on self-reported data and are, therefore, likely to contain some kind of bias.

    Practical implications

    Goal setting in organizations has to accommodate for situations, where productivity goals constrain security policy compliance. Introducing the proposed goal setting concept based on relevant actionable behavioral recommendations can help mitigate issues in such situations.

    Originality/value

    This work furthers the understanding of the factors affecting employee security compliance. Furthermore, the proposed concept can help maximizing the positive effects of goal setting in organizations by mitigating the negative effects through the introduction of meaningful and actionable information security goals.

  • 574.
    Mayer, Peter
    et al.
    Faculty of Computer Sciences, Technische Universitat Darmstadt, Darmstadt, Hessen, Germany.
    Kirchner, Jan
    Technische Universität Darmstadt.
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    A second look at password composition policies in the wild: Comparing samples from 2010 and 20162017Inngår i: Proceedings of the Thirteenth Symposium on Usable Privacy and Security (SOUPS 2017), Usenix, The advanced computer systems associaton , 2017, s. 13-28Konferansepaper (Fagfellevurdert)
    Abstract [en]

    In this paper we present a replication and extension of the study performed by Flor^encio and Herley published at SOUPS 2010. They investigated a sample of US websites, examining different website features' effects on the strength of the website's password composition policy (PCP). Using the same methodology as in the original study, we re-investigated the same US websites to identify differences over time. We then extended the initial study by investigating a corresponding sample of German websites in order to identify differences across countries. Our findings indicate that while the website features mostly retain their predicting power for the US sample, only one feature affecting PCP strength translates to the German sample: whether users can choose among multiple alternative websites providing the same service. Moreover, German websites generally use weaker PCPs and, in particular, PCPs of German banking websites stand out for having generally low strength PCPs

     

  • 575.
    Mayer, Peter
    et al.
    Technische Universitat Darmstadt, Germany.
    Kunz, Alexandra
    Technische Universität Darmstadt, Germany.
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Technische Universität Darmstadt , Germany.
    Reliable behavioural factors in the information security context2017Inngår i: ARES '17 Proceedings of the 12th International Conference on Availability, Reliability and Security, New York: Association for Computing Machinery (ACM), 2017, artikkel-id UNSP 9Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Users do often not behave securely when using information technology. Many studies have tried to identify the factors of behavioural theories which can increase secure behaviour. The goal of this work is to identify which of the factors are reliably associated with secure behaviour across multiple studies. Those factors are of interest to information security professionals since addressing them in security awareness and education campaigns can help improving security related processes of users. To attain our goal, we conducted a systematic literature review and assessed the reliability of the factors based on the effect sizes reported in the literature. Our results indicate that 11 out of the 14 factors from well established behavioural theories can be associated with reliable effects in the information security context. These factors cover very different aspects: influence of the users skills, whether the environment makes it possible to exhibit secure behaviour, the influence of friends or co-workers, and the perceived properties of the secure behaviour (e.g. response cost). Also, we identify areas, where more studies are needed to increase the confidence of the factors' reliability assessment.

  • 576.
    Mayer, Peter
    et al.
    Technische Universität Darmstadt.
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Technische Universität Darmstadt.
    Addressing misconceptions about password security effectively2018Inngår i: Proceedings of 7th Workshop on Socio-Technical Aspects in Security and Trust, Orlando, Florida, USA, December 2017 (STAST 2017), Association for Computing Machinery , 2018, s. 1-12Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Nowadays, most users need more passwords than they can handle. Consequently, users have developed a multitude of strategies to cope with this situation. Some of these coping strategies are based on misconceptions about password security. In such cases, the users are unaware of their insecure password practices. Addressing the misconceptions is vital in order to decrease insecure coping strategies. We conducted a systematic literature review with the goal to provide an overview of the misconceptions about password security. Our literature review revealed that misconceptions exist in basically all aspects of password security. Furthermore, we developed interventions to address these misconceptions. Then, we evaluated the interventions’ effectiveness in decreasing the misconceptions at three small and medium sized enterprises (SME). Our results show that the interventions decrease the overall prevalence of misconceptions significantly in the participating employees.

  • 577. Mayer, Peter
    et al.
    Volkamer, Melanie
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Secure and Efficient Key Derivation in Portfolio Authentication Schemes Using Blakley Secret Sharing2015Inngår i: Proceedings of the 31st Annual Computer Security Applications Conference, Association for Computing Machinery (ACM), 2015, s. 431-440Konferansepaper (Fagfellevurdert)
  • 578.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Developing the design of a role-play in a professional development2016Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The poster shows how a role-play conducted by teachers can be developed through the methodology of educational design research. The role-play represents a classroom situation and is an instructional activity as part of a two-year long teacher professional development program. The implementation focuses on some of the features identified as important in an effective professional development. The aim of the role-play is to practice and deepen mathematics teachers’ knowledge and skills of stimulating mathematically gifted pupils higher order thinking. After the development of the role-play, the study can move forward and include; teachers’ change in instruction and pupil learning in order to study the effectiveness of the role-play as a part of a professional development program.

  • 579.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Harnessing teachers’ perspectives: Recognizing mathematically highly able pupils and orchestrating teaching for them in a diverse ability classroom2018Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    There is a lack of research that explores teachers’ perspectives on teaching highly able pupils (HAPs) in the diverse ability classroom. Instead, pupils’ perspectives are common, such studies often concluding that teachers need more professional development or that they fail to support HAPs. Consequently, previous research does not support teachers in how to implement teaching that includes HAPs. This thesis aims to harness teachers’ perspectives of pedagogical possibilities that enable learning opportunities for mathematically highly able pupils (MHAPs). By comparing pupils’ (n=264) relative achievement on two different tests, traditional and non-traditional, the first part of this thesis explores teachers’ possibilities to recognize MHAPs. The results show that pupils who achieved highly on the non-traditional test, but not on the other, have higher problem-solving competence compared to pupils who achieved highly on the traditional test instead. The second part presents a teacher-initiated investigation of pupils’ perceptions of challenging mathematical tasks. The findings indicate that the developed tool can help teachers find suitable tasks for MHAPs. The final part uses positioning theory to analyze teachers’ (N=17) discussions and probe their perceptions on orchestrating teaching MHAPs. The findings show that the teachers have knowledge of how to recognize and support MHAPs. Specifically, the teachers express possibilities with challenging tasks and differentiated education to meet MHAPs’ learning needs. Furthermore, the teachers perceived fewer rights than duties to orchestrate teaching for MHAPs’, for example, to continuously asses them. The studies in this thesis support teachers to orchestrate teaching including MHAPs in the diverse ability classroom. Both practice and research can be guided by what the teachers in these studies perceived as possible to do to orchestrate such teaching. Thereby support is given to teachers, from teachers, through research.

  • 580.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    High achiever! Always a high achiever?: A comparison of student achievements on mathematical tests with different aims and goals2014Licentiatavhandling, monografi (Annet vitenskapelig)
    Abstract [en]

    This study explored changes in relative achievement over time. It also investigated differences in how two groups of students activate mathematical competencies. The aim of the study was to investigate students’ relative achievement in mathematics over time, and how mathematical competencies can be used to explore differences between groups of students on a non-curriculum based test in mathematics. The study was divided in two parts. Study 1 compared students’ (n=568) relative achievement in two national tests in mathematics (years 3 and 6). Study 1 explored changes in relative achievement between the two national tests as well as differences in relative achievement between the national test in year 6 and the mathematical kangaroo in year 7 (age 13). The study identified, from a sample (n=264) of study 1, two groups of students with high achievements in only one of the tests, the national test in year 6 or the mathematical kangaroo. Study 2 explored how differences between those students relative achievement on the mathematical kangaroo could be explained through activation of mathematical competencies. The results in study 1 show that students undergo large changes, both increases and decreases, in relative achievement between the national tests in years 3 and 6. Study 2 shows how the two identified groups activate the mathematical competencies differently on the mathematical kangaroo. 9% of the students achieve highly in the mathematical kangaroo although they do not in the national test. The study implicates the importance of using non-curriculum bounded tests to identify strength in mathematical competencies among students that not are able to show them through the national test.

  • 581.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Manuscript: Teachers’ views on teaching highly able pupils in diverse ability classroomManuskript (preprint) (Annet vitenskapelig)
  • 582.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Mathematically Able but Yet Underachieving in School Mathematics2013Inngår i: Proceedings of the EightŠ Congress of the European Society for Research in Mathematics Education / [ed] Behiye Ubuz, Çiğdem Haser, Maria Alessandra Mariotti, Ankara, Turkey, 2013, s. 1264-1265Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Teacher observation has shown that some pupils achieve very high on the Kangaroo Competition test (KC) but very low on the Swedish National test in Mathematics (SNM). This study will investigate the number of pupils who have high achievement scores on the KC (top 10%) but low achievement scores on the SNM (bottom 50%). Individual results on the SNM given in grade 6 (age 12) will be compared to results on the KC given in grade 7; concerning approximately 700 individuals. Results will give an example of the quantity of mathematically able pupils who underachieve in School Mathematics in Sweden. Data interpretation will connect this study to international research concerning mathematical abilities and mathematical achievement among mathematically able pupils.

  • 583.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Karlstads kommun.
    Med rätt att utmanas - i en skola för alla: Att utveckla verksamheten kring att inkludera elever med särskild begåvning i lärande.2018Rapport (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Detta är en rapport av ett skolutvecklingsprojekt som pågått från och med våren 2015 till och med våren 2017, det vill säga tre år. Projektets övergripande syfte var att möta den problematik som finns i svensk skola kring att elever med särskild begåvning ofta är understimulerade och ofta lämnas utan stöd och stimulans att vidareutvecklas i kunskap genom undervisning i skolan. Ett mer konkret syfte var att på vetenskaplig grund utveckla innehåll och undervisningssituationer i matematik för elever med särskild begåvning i matematik i det svenska heterogena klassrummet. Målet var att öka kunskapen hos skolpersonal om dessa elever, deras behov, styrkor och svårigheter, samt deras rättigheter. Ett mer detaljerat mål var att definiera vilken typ av innehåll som lämpar sig för elever med särskild begåvning, både med avseende på matematiska förmågor och specifikt matematikinnehåll. Ett ytterligare mål var att identifiera några typer av undervisningssituationer som är speciellt lämpliga för dessa elever i det vanliga klassrummet. Som resultat av projektet har 14 grundskolelärare i Karlstads kommun och en i Borlänge kommun utvecklat sin kompetens att identifiera elever med särskild begåvning i sina klassrum. De har också utvecklat sin kompetens i att möta dessa elever i undervisning. Lärarna uppger vidare att de har ändrat sitt tankesätt kring hur undervisning kan gå till, vilket lett till att de nu utmanar alla elever i klassrummet mer. Genom projektet har vi analyserat, utvecklat och i tre interventioner prövat tio matematikuppgifter. Denna rapport beskriver projektet och de utvecklade uppgifterna, som finns presenterade i rapporten, är ett sätt att sprida projektet vidare till andra pedagogiska verksamheter. Vår förhoppning är att rapporten kan hjälpa andra att utveckla sina verksamheter så att fler elever med särskild begåvning får stöd och stimulans att utvecklas vidare i kunskap genom undervisning i svensk skola.

  • 584.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Problem solving competency and the mathematical kangaroo2015Inngår i: Proceedings of the Ninth Congress of the European Society for Research in Mathematics Education / [ed] Konrad Krainer, Naďa Vondrová, Prague, Czech Republic, 2015, s. 1095-1096Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The goal of the study was to investigate differences in how two groups of students activated mathematical competencies in the mathematical kangaroo (MK). The two groups, group 1 and 2, were identified from a sample of 264 students (grade 7, age 13) through high achievement (top 20 %) in only one of the tests: the MK or a curriculum bounded test (CT). Analysis of mathematical competencies showed that the high achievers in the MK, activated the problem solving competency to a greater extent than the high achievers in the CT, when doing the MK. The results indicate the importance of using non-traditional tests in the assessment process of students to be able to find students that might possess good mathematical competencies although they do not show it on curriculum bounded tests.

  • 585.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Sverige och undervisning av elever med särskild begåvning i slutet av 20182019Inngår i: Kognition og Pædagogik: Tidskrift om gode læringsmiljøer, ISSN 0906-6225, Vol. 29, nr 111-112, s. 42-47Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
    Abstract [sv]

    Denna artikel bygger på en historisk beskrivning hur undervisning av elever med särskild begåvade börjat ta plats i det svenska skolsystemet. Syftet med artikeln är att ge en bild av hur långt Sverige har kommit, i slutet av 2018, i utvecklingen av undervisning av elever med särskild begåvning. Det historiska perspektivet är tänkt att ge läsaren en bättre förståelse och bakgrund till lägesbeskrivningen. Artikeln avslutas med en kort summering, samt förslag på prioriterade satsningar för att lyckas med att etablera hållbara strukturer för undervisning av dessa barn och elever.

  • 586.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Swedish teachers’ perspectives on educating highly able pupils2019Inngår i: Alle Talente wertschätzen grenz- und beziehungsgebiete der Mathematikdidaktik ausschöpfen: Festschrift für Marianne Nolte / [ed] K. Pamperien & A. Pöhls, Münster: VTM-Verlag , 2019Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    This text is a brief summary of two studies presented in my doctoral thesis. The aim of the studies was to capture teachers’ perspectives on orchestrating teaching of mathematically highly able pupils (MHAPs) in diverse classroom. Positioning theory was used to analyze teachers’ (N=17) discussions in the context of a long term (two-year, 120 h) professional development programme on gifted education. The results show that, when teachers connect theories of gifted education with their teaching expertise, they express possibilities and obstacles, but also rights and duties, in their professional task, to include MHAPs in classroom learning. The teachers express a duty to collaborate with colleagues to meet the learning needs of MHAPs. Differentiation and well-composed mathematical tasks are suggested as possible ways of catering for those needs. Through the lens of positioning theory, the results show that teachers have deep knowledge of what constitutes high ability and that they have the power to orchestrate teaching to meet the needs of MHAPs. Whether they can or do use this power, however, is a question yet to be explored.

  • 587.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Teachers' Views on Teaching Highly Able Pupils in a Heterogeneous Mathematics Classroom2020Inngår i: Scandinavian Journal of Educational Research, ISSN 0031-3831, E-ISSN 1470-1170, s. 1-19Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Aiming to bring teachers' perspectives to research, teachers' (N = 12) discussions are explored in the context of a professional development program on teaching highly able pupils (HAPs) mathematics. The findings show that the teachers perceive they have the competence to recognize HAPs, for example through continuous assessment. However, they express that collaboration with colleagues is necessary and that they would like their principals' acknowledgement for their competence. They connect and verbalize their practical expertise with theories of teaching HAPs and demonstrate several criteria for teaching that successfully meet pupils' learning needs in heterogeneous classrooms. Thus, they feel confident in how to orchestrate teaching that is inclusive of HAPs in heterogeneous mathematics classrooms.

  • 588.
    Mellroth, Elisabet
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap. Karlstads kommun.
    The suitability of rich learning tasks from a pupil perspective2017Inngår i: CERME 10: Proceedings of the Tenth Congress of European Society for Research in Marhematics Education, European Society for Research in Mathematics Education, 2017, s. 1162-1169Konferansepaper (Fagfellevurdert)
    Abstract [en]

    The construction of tasks is important to challenge pupils, but the exploration of pupils’ perceptions connected to their work with tasks, is rare. This paper presents the results of a study using a tool aimed at measuring pupils’ perception of joy and interest connected to ‘rich learning tasks’ by comparing the views of mathematically promising pupils and others. Two tasks were pre- and postevaluated, the first by 139 and the second by 106 pupils from grade 4-9. The results indicate that the tool is suited for the exploration of pupils’ views, especially as it can be deduced from the comparison that mathematically promising pupils perceived both tasks more positively than the other pupils, and that the non-identified pupils became more positive after working especially with one of the tasks.

  • 589.
    Mellroth, Elisabet
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Bergwall, Andreas
    Örebro University.
    Kollegialt lärande kring lärsituationer för gymnasieelever med särskild begåvning.2020Konferansepaper (Fagfellevurdert)
    Abstract [sv]

    Design research och Cultural-Historical Activity Theory kommer i denna studie användas för att studera kollegialt lärande i matematik. Studien utförs med lärare som deltar i ett skolutvecklingsprojekt med ett delsyfte att utveckla undervisningen för elever med särskild begåvning. Forskningen syftar till att bidra med kunskap om kollegialt lärande som en hållbar utvecklingsprocess i en kommun.

  • 590.
    Mellroth, Elisabet
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Boesen, Jesper
    Jönköping University.
    Noticing pupils’ mathematical potential: A proposal for guiding teachers.2019Inngår i: Proceedings of the Eleventh Congress of the European Society for Research in Mathematics Education (CERME11, February 6 – 10, 2019) / [ed] Jankvist, U. T., Van den Heuvel-Panhuizen, M., & Veldhuis, M., Utrecht, 2019, s. 3688-3695Konferansepaper (Fagfellevurdert)
    Abstract [en]

    It has been shown to be problematic for teachers to use Krutetskii´s definition of mathematicalabilities to recognize mathematically highly able pupils (MHAPs). Aiming to concretize whatteachers can notice in pupils’ problem-solving processes, we connect a 10-year-old boy’s problemsolvingprocess to some of the abilities defined by Krutetskii. The results give clear descriptions ofwhat teachers can observe in pupils’ mathematical activities to notice their mathematical potential.We concretize, for example, how a pupil’s abilities to grasp a problem’s formal structure and togeneralize can be observed. To be able to notice MHAPs, teachers need research-based support onhow and what to observe in their pupils. Our proposed guide needs to be tested and validated toexplore if it will help teachers to notice MHAPs s and subsequently support their learning.

  • 591.
    Mellroth, Elisabet
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Margrain, Valerie
    Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Institutionen för pedagogiska studier (from 2013).
    Teaching highly able learners in diverse classrooms: Pedagogical possibilities through collaboration.2019Inngår i: Including the highly gifted and creative students: Current ideas and future directions. : Proceedings of the 11th International conference on mathematics creativity and giftedness. / [ed] Marianne Nolte, Münster, 2019, s. 21-31Konferansepaper (Annet vitenskapelig)
    Abstract [en]

    We argue in this paper that, with appropriate support, teaching of highly able learner can occur in diverse classrooms. We draw on a constructivist theory of learning and a differentiation paradigm (Dai & Chen, 2013). The claim that teachers can orchestrate teaching for highly able students in diverse classrooms is considered with evidence of our own and other data, warrant, backing, qualifier and rebuttal. Results from many studies have given knowledge of learning needs of mathematically highly able learners as well as of successful teaching to meet a diversity of learners. Drawing on our research, and work with school development, we share ideas about possibilities for teachers to support learning for all students, that is, including the highly able, within a diverse classroom. In particular, we advocate the possibilities from professional collaboration and our practice examples illustrate this claim.

  • 592.
    Mellroth, Elisabet
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Thyberg, Annika
    Karlstads kommun.
    Spielfelder2018Inngår i: Alle zusammen!: Offene, substanzielle Problemfelder als Gestaltungsbaustein für inklusiven Mathematikunterricht / [ed] Ralf Benölken, Nina Berlinger und Marcel Veber, Münster: WTM Verlag für wissenschafliche Texte und Medien Münster , 2018, s. 37-49Kapittel i bok, del av antologi (Fagfellevurdert)
  • 593.
    Mellroth, Elisabet
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    van Bommel, Jorryt
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Liljekvist, Yvonne
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Elementary teachers on orchestrating teaching for mathematically highly able pupils2019Inngår i: The Montana Mathematics Enthusiast, ISSN 1551-3440, E-ISSN 1551-3440, Vol. 16, nr 1-3, s. 127-153, artikkel-id 8Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Studies on high ability in mathematics rarely take a teacher’s perspective. The purpose of our study is to add such a perspective, which we will do by using positioning theory to analyze elementary teachers’ discussions on mathematical tasks, aiming to challenge all pupils, including the highly able. The study is conducted in the context of a two-year long teacher professional development program on high ability. Teachers expressed both their teaching and the mathematical tasks as helpful in orchestrating teaching suitable for highly able pupils. They highlight the opportunities given by some tasks as well as the importance of guiding highly able pupils to go further in such tasks. However, they expressed their own limited mathematical knowledge and time needed for pupils with learning difficulties as obstacles to orchestrate teaching for the highly able. The results show that it is important to, in close cooperation with teachers, further explore how to orchestrate teaching that challenges highly able pupils.

  • 594.
    Mellroth, Elisabet
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Vinerean-Bernhoff, Mirela
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Boström, Mattias
    City of Karlstad, Sundsta- Älvkullegymnasiet.
    Liljekvist, Yvonne
    Karlstads universitet, Fakulteten för teknik- och naturvetenskap, Avdelningen för matematik. Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013). Karlstads universitet, Fakulteten för humaniora och samhällsvetenskap (from 2013), Institutionen för pedagogiska studier (from 2013).
    Differentiated instruction using learning management systems in upper secondary school and university level: A research proposal2019Inngår i: Including the highly gifted and creative students: Current ideas and future directions.: Proceedings of the 11th International conference on mathematics creativity and giftedness. / [ed] Marianne Nolte, Münster, 2019, s. 378-380Konferansepaper (Fagfellevurdert)
    Abstract [en]

    t. There is a need to develop an infrastructure to support and maintain teaching that both challenge all students at their knowledge level and open up the possibility to applying mathematical knowledge in innovative and creative ways. Learning management systems (LMS) are widely used throughout the Swedish school system. However, recent studies shows that few teachers use this resource for teaching development, i.e., using LMS as an instrument to improve forthcoming lessons. In this poster a research proposal is outlined. The aim is to explore how LMS can be used as an instrument for differentiated instruction throughout the intertwined processes of planning, teaching, studying, follow up and assessment.

  • 595.
    Mesodiakaki, Agapi
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Adelantado, Ferran
    Open University of Catalonia, Spain.
    Alonso, Luis
    Signal Theory and Communications Department, Technical University of Catalonia, Spain.
    Renzo, Marco Di
    Laboratoire des Signaux et Systèmes, CNRS, CentraleSupélec, UnivParis Sud, Université Paris-Saclay, France.
    Verikoukis, Christos
    Centre Tecnològic de Telecomunicacions de Catalunya, Barcelona, Spain.
    Energy- and Spectrum-Efficient User Association in Millimeter-Wave Backhaul Small-Cell Networks2017Inngår i: IEEE Transactions on Vehicular Technology, ISSN 0018-9545, E-ISSN 1939-9359, Vol. 66, nr 2, s. 1810-1821Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Macrocells are expected to be densely overlaid by small cells (SCs) to meet the increasing capacity demands. Due to their dense deployment, some SCs will not be connected directly to the core network and thus they may forward their traffic to the neighboring SCs until they reach it, thereby forming a multi-hop backhaul (BH) network. This is a promising solution, since the expected short length of BH links enables the use of millimeter wave (mmWave) frequencies to provide high capacity BH. In this context, user association becomes challenging due to the multihop BH architecture and therefore new optimal solutions should be developed. Thus, in this paper, we study the user association problem aiming at the joint maximization of network energy and spectrum efficiency, without compromising the user quality of service. The problem is formulated as an "-constraint problem, which considers the transmit energy consumption both in the access network, i.e., the links between the users and their serving cells, and the BH links. The optimal Pareto front solutions of the problem are analytically derived for different BH technologies and insights are gained into the energy and spectrum efficiency trade-off. The proposed optimal solutions, despite their high complexity, can be used as a benchmark for the performance evaluation of user association algorithms. We also propose a heuristic algorithm, which is compared with reference solutions under different traffic distribution scenarios and BH technologies. Our results motivate the use of mmWave BH, while the proposed algorithm is shown to achieve near-optimal performance.

  • 596.
    Mesodiakaki, Agapi
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Adelantado, Ferran
    Open University of Catalonia (UOC), Barcelona, Spain.
    Antonopoulos, Angelos
    Telecommunications Technological Centre of Catalonia (CTTC), Castelldefels, Spain.
    Alonso, Luis
    Technical University of Catalonia (UPC), Signal Theory and Communications Barcelona, Spain.
    Verikoukis, Christos
    Telecommunications Technological Centre of Catalonia (CTTC), Castelldefels, Spain.
    Energy and spectrum efficient user association in 5G heterogeneous networks2016Inngår i: Personal, Indoor, and Mobile Radio Communications (PIMRC), 2016 IEEE 27th Annual International Symposium on, IEEE, 2016, s. 1-6Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Due to the dense small cell deployment to cope with the increased data traffic of fifth generation (5G) networks, the direct backhaul (BH) connection of all small cells to the core network becomes challenging. To that end, millimeter wave (mmWave) is a promising solution for cost-efficient high capacity small cell BH links. However, due to the severe signal attenuation at high frequencies, mmWave can provide good coverage only for short distances, thus favoring a multi-hop 5G BH architecture. In this context, user association that impacts both the network and user performance calls for BH-aware strategies. Hence, in this paper, we study the user association problem aiming at the joint energy and spectrum efficiency maximization of the network, without compromising the user quality of service. The problem is formulated as a generalized assignment problem, which considers the capacity and energy consumption both in the access network and BH links. Provided that the considered problem is shown to be NP-hard, we employ optimization techniques to obtain an upper bound on system performance. We also propose a low complexity algorithm, which is shown to outperform the state-of-the-art while achieving near-optimal performance.

  • 597.
    Mesodiakaki, Agapi
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för ekonomi, kommunikation och IT, Avdelningen för datavetenskap.
    Enrica, Zola
    UPC.
    Mattias, Ferndahl
    Gothic AB.
    Tao, Cai
    HWSE.
    Energy Efficient Line-of-Sight Millimeter Wave Small Cell Backhaul: 60, 70, 80 or 140 GHz?2016Inngår i: World of Wireless, Mobile and Multimedia Networks (WoWMoM), 2016 IEEE 17th International Symposium on A, IEEE, 2016Konferansepaper (Fagfellevurdert)
  • 598.
    Mesodiakaki, Agapi
    et al.
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Zola, Enrica
    Dept. of Network Engineering, UPC - BarcelonaTECH, Spain.
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    User Association in 5G Heterogeneous Networks with Mesh Millimeter Wave Backhaul Links2017Inngår i: 18th IEEE International Symposium on a World of Wireless, Mobile and Multimedia Networks (WoWMoM), IEEE, 2017Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Fifth generation (5G) wireless networks will target at energy and spectrum efficient solutions to cope with the increasing demands in capacity and energy efficiency. To achieve this joint goal, dense networks of small cells (SCs) are expected to overlay the existing macro cells. In parallel, for the SC connection to the core network, a promising solution lies in a mesh network of high capacity millimeter wave backhaul (BH) links. In the considered 5G architecture, each SC is able to forward its BH traffic to the core network through alternative paths, thus offering high BH network reliability. In this context, the joint problem of user association and BH routing becomes challenging. In this paper, we focus on this problem targeting at energy and spectrum efficient solutions. A low-complexity algorithm is proposed, which bases its user association and BH routing decision i) on minimizing the spectrum resources to guarantee the user rate, so as to provide high spectrum efficiency, and ii) on minimizing both the access network and BH route power consumption to provide high energy efficiency. Our results show that our solution provides better trade-offs between energy and spectrum efficiency than the state-of-the-art in 3GPP scenarios.

  • 599.
    Mesodiakaki, Agapi
    et al.
    Department of Informatics, Aristotle University of Thessaloniki, Greece.
    Zola, Enrica
    UPC-BarcelonaTECH, Barcelona, Spain.
    Santos, Ricardo
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Kassler, Andreas
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Optimal User Association, Backhaul Routing and Switching off in 5G Heterogeneous Networks with Mesh Millimeter Wave Backhaul Links2018Inngår i: Ad hoc networks, ISSN 1570-8705, E-ISSN 1570-8713, Vol. 78, s. 99-114Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Next generation, i.e., fifth generation (5G), cellular networks will provide a significant higher capacity per area to support the ever-increasing traffic demands. In order to achieve that, many small cells need to be deployed that are connected using a combination of optical fiber links and millimeter-wave (mmWave) backhaul architecture to forward heterogeneous traffic over mesh topologies. In this paper, we present a general optimization framework for the design of policies that optimally solve the problem of where to associate a user, over which links to route its traffic towards which mesh gateway, and which base stations and backhaul links to switch off in order to minimize the energy cost for the network operator and still satisfy the user demands. We develop an optimal policy based on mixed integer linear programming (MILP) which considers different user distribution and traffic demands over multiple time periods. We develop also a fast iterative two-phase solution heuristic, which associates users and calculates backhaul routes to maximize energy savings. Our strategies optimize the backhaul network configuration at each timeslot based on the current demands and user locations. We discuss the application of our policies to backhaul management of mmWave cellular networks in light of current trend of network softwarization (Software-Defined Networking, SDN). Finally, we present extensive numerical simulations of our proposed policies, which show how the algorithms can efficiently trade-off energy consumption with required capacity, while satisfying flow demand requirements.

  • 600. Moerlands, Frans
    et al.
    van Bommel, Jorryt
    Karlstads universitet, Fakulteten för hälsa, natur- och teknikvetenskap (from 2013), Institutionen för matematik och datavetenskap (from 2013).
    Alla kan räkna med ägg2017Inngår i: Nämnaren : tidskrift för matematikundervisning, ISSN 0348-2723, Vol. 1, nr 201, s. 15-21Artikkel i tidsskrift (Annet (populærvitenskap, debatt, mm))
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