Change search
Refine search result
1234567 1 - 50 of 5392
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf
Rows per page
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sort
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
  • Standard (Relevance)
  • Author A-Ö
  • Author Ö-A
  • Title A-Ö
  • Title Ö-A
  • Publication type A-Ö
  • Publication type Ö-A
  • Issued (Oldest first)
  • Issued (Newest first)
  • Created (Oldest first)
  • Created (Newest first)
  • Last updated (Oldest first)
  • Last updated (Newest first)
  • Disputation date (earliest first)
  • Disputation date (latest first)
Select
The maximal number of hits you can export is 250. When you want to export more records please use the 'Create feeds' function.
  • 1. Abdel-Rehim, M.
    et al.
    Altun, Zeki
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    New trend in sample preparation: On-line microextraction in packed syringe (MEPS) for LC and GC applications, Part II, Determination of ropivacaine and its metabolites in human plasma samples using MEPS-LC-MS-MS2004In: J. Mass Spectr., 39 (2004) 1488-1493Article in journal (Refereed)
  • 2. Abdel-Rehim, M.
    et al.
    Carlsson, Gunilla
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Paper Surface Centre. Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences. Karlstad University, Faculty of Technology and Science, Materials Science.
    Bielenstein, M.
    Arvidsson, T.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Evaluation of Solid-Phase microextraction (SPME) for Study of the protein Binding in Human Plasma Samples,2000In: J. Chromatogr. Sci., 38 (2000) 458-464Article in journal (Refereed)
  • 3. Abdel-Rehim, M.
    et al.
    Hassan, Z.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Hassan, M.
    Determination of Busulphan in plasma samples by gas chromatography-mass spectrometry (GC-MS) using on-line derivatization utilizing solid-phase microextraction (SPME)2003In: J. Therapeutic Drug Monitoring, 25 (2003) 400-406Article in journal (Refereed)
  • 4. Abdel-Rehim, M.
    et al.
    Skansen, P.
    Vita, M.
    Hassan, Z.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Hassan, M.
    Microextraction in packed syringe / liquid chromatography /electrospray tandem mass spectrometry (MEPS/LC/MS/MS) for quantification of olomoucine in human plasma samples2005In: Anal.Chim. Acta., 539 (2005) 35-39Article in journal (Refereed)
  • 5.
    Abdel-Rehim, Mohamed
    et al.
    AstraZeneca R&D Södertälje, Södertälje, Sweden.
    Andersson, L.I.
    AstraZeneca R&D Södertälje, Södertälje, Sweden.
    Altun, Zeki
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Microextraction in Packed Syringe Online with Liquid Chromatography-Tandem Mass Spectrometry: Molecularly imprinted polymer as packing material for MEPS in selective extraction of ropivacaine from plasma2006In: Journal of Liquid Chromatography & Related Technologies, ISSN 1082-6076, E-ISSN 1520-572X, Vol. 29, no 12, p. 1725-1736Article in journal (Refereed)
    Abstract [en]

    The excellent performance of a new sample preparation method, microextraction in packed syringe (MEPS), was recently illustrated by online LC‐MS and GS‐MS assays of local anaesthetics in plasma samples. In the method, approximately 1 mg of solid packing material was inserted into a syringe (100–250 µL) as a plug. Sample preparation took place on the packed bed. The new method was easy to use, fully automated, of low cost, and rapid in comparison with previously used methods. This paper presents the use of molecularly imprinted polymers (MIPs) as packing material for higher extraction selectivity. Development and validation of a method for MIP‐MEPS online with LC‐MS‐MS using ropivacaine in plasma as model compound were investigated. A bupivacaine imprinted polymer was used. The method was validated and the standard curves were evaluated by means of quadratic regression and weighted by inverse of the concentration: 1/x for the calibration range 2–2000 nM. The applied polymer could be used more than 100 times before the syringe was discarded. The extraction recovery was 60%. The results showed high correlation coefficients (R 2 >0.999) for all runs. The accuracy, given as a percentage deviation from the nominal concentration values, ranged from -6% to 3%. The precision, given as the relative standard deviation, at three different concentrations (QC samples) was consistently about 3% to 10%. The limit of quantification was 2 nM.

  • 6. Abdel-Rehim, Mohamed
    et al.
    Dahlgren, Marie
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Quantification of ropivacaine and its major metabolites in human urine samples utilizing microextraction in packed syringe automated with liquid chromatography-tandem mass spectrometry (MEPS-LC-MS-MS)2006In: J. Sep. Sci., 29 (2006) 1658-1661Article in journal (Refereed)
  • 7. Abdel-Rehim, Mohamed
    et al.
    Dahlgren, Marie
    Claude, Saturnin
    Tabacchi, Raphael
    Blomberg, Lars G
    Karlstad University, Faculty of Technology and Science, Department of Chemistry and Biomedical Sciences.
    Microextraction in packed syringe (MEPS) utilizing methylcyanopropyl silarylene as coating polymer for extraction of drugs in biological samples,2006In: J. Liq. Chromatogr. & Relat. Technol., 29 (2006) No. 17, 2537-2544Article in journal (Refereed)
  • 8.
    Abdollahi, Kamran
    et al.
    Computer and Science Department Iran University of Science and Technology Tehran, Iran.
    Shams Shafigh, Alireza
    Computer and Science Department Iran University of Science and Technology Tehran, Iran.
    Kassler, Andreas
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT.
    Improving Performance of On Demand Multicast Routing by deleting lost join query packet2010In: Proceedings of The Sixth Advanced International Conference on Telecommunications - AICT 2010, IEEE conference proceedings, 2010, p. 316-322Conference paper (Refereed)
    Abstract [en]

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

  • 9. Abu Bakar, Sakhinah
    et al.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Characterization of essential proteins in proteins interaction networks2013In: Journal of Quality Measurement and Analysis, ISSN 1823-5670, Vol. 9, no 2, p. 11-26Article in journal (Refereed)
  • 10. Acedo, L.
    et al.
    Santos, A.
    Bobylev, Alexander
    Karlstad University, Faculty of Technology and Science, Department of Mathematics.
    On the derivation of a high-velocity tail from the Boltzmann-Fokker-Planck equation for shear flow2002In: J. Statist. Phys, Vol. 109:5-6Article in journal (Refereed)
  • 11.
    Achberger, Christine
    et al.
    Göteborgs universitet.
    Chen, Deliang
    Göteborgs universitet.
    Rayner, David
    Göteborgs universitet.
    Nyberg, Lars
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Centre for Climate and Safety.
    Persson, Gunn
    SMHI.
    Future rainfall and flooding in Sweden: an integrative project to support climate-adaptation actions2013Conference paper (Refereed)
  • 12. Ackelh, A.S.
    et al.
    Colombo, R.M.
    Hille, S.C.
    Muntean, Adrian
    Institute for Complex Molecular Systems & Centre for Analysis, Scientific computing and Applications, Eindhoven University of Technology.
    Preface to "modeling with measures"2015In: Mathematical Biosciences and Engineering, ISSN 1547-1063, E-ISSN 1551-0018, Vol. 12, no 2Article in journal (Refereed)
  • 13.
    Adamczyk, Krzysztof
    et al.
    Department of Materials Science and Engineering, Trondheim, Norway.
    Søndenå, Rune
    Department for Solar Energy, IFE, Kjeller, Norway.
    Stokkan, Gaute
    Sintef Materials and Chemistry, Trondheim, Norway.
    Looney, Erin
    Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
    Jensen, Mallory
    Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
    Lai, Barry
    Advanced Photon Source, Argonne National Laboratory, Lemont, Illinois 60439, USA.
    Rinio, Markus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Di Sabatino, Marisa
    Department of Materials Science and Engineering, NTNU, A. Getz vei 2B, NO-7491 Trondheim, Norway.
    Recombination activity of grain boundaries in high-performance multicrystalline Si during solar cell processing2018In: Journal of Applied Physics, ISSN 0021-8979, E-ISSN 1089-7550, Vol. 123, no 5, p. 1-6, article id 055705Article in journal (Refereed)
    Abstract [en]

    In this work, we applied internal quantum efficiency mapping to study the recombination activity of grain boundaries in High Performance Multicrystalline Silicon under different processing conditions. Wafers were divided into groups and underwent different thermal processing, consisting of phosphorus diffusion gettering and surface passivation with hydrogen rich layers. After these thermal treatments, wafers were processed into heterojunction with intrinsic thin layer solar cells. Light Beam Induced Current and Electron Backscatter Diffraction were applied to analyse the influence of thermal treatment during standard solar cell processing on different types of grain boundaries. The results show that after cell processing, most random-angle grain boundaries in the material are well passivated, but small-angle grain boundaries are not well passivated. Special cases of coincidence site lattice grain boundaries with high recombination activity are also found. Based on micro-X-ray fluorescence measurements, a change in the contamination level is suggested as the reason behind their increased activity.

  • 14.
    Adamczyk, Krzysztof
    et al.
    Department of Materials Science and Engineering, Trondheim, Norway.
    Søndenå, Rune
    Department for Solar Energy, IFE, Kjeller, Norway.
    You, Chang Chuan
    Department for Solar Energy, IFE, Kjeller, Norway.
    Stokkan, Gaute
    Sintef Materials and Chemistry, Trondheim, Norway.
    Lindroos, Jeanette
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Rinio, Markus
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Engineering and Physics (from 2013).
    Di Sabatino, Marisa
    Department of Materials Science and Engineering, Trondheim, Norway.
    Recombination Strength of Dislocations in High-Performance Multicrystalline/Quasi-Mono Hybrid Wafers During Solar Cell Processing2018In: Physica Status Solidi (a) applications and materials science, ISSN 1862-6300, E-ISSN 1862-6319, Vol. 215, no 2, article id 1700493Article in journal (Refereed)
    Abstract [en]

    Wafers from a hybrid silicon ingot seeded in part for High Performance Multicrystalline, in part for a quasi-mono structure, are studied in terms of the effect of gettering and hydrogenation on their final Internal Quantum Efficiency.The wafers are thermally processed in different groups – gettered and hydrogenated. Afterwards, a low temperature heterojunction with intrinsic thin layer cell process is applied to minimize the impact of temperature. Such procedure made it possible to study the effect of different processing steps on dislocation clusters in the material using the Light Beam Induced Current technique with a high spatial resolution. The dislocation densities are measuredusing automatic image recognition on polished and etched samples. The dislocation recombination strengths are obtained by a correlation of the IQE with the dislocation density according to the Donolato model. Different clusters are compared after different process steps. The results show that for the middle of the ingot, the gettering step can increase the recombination strength of dislocations by one order of magnitude. A subsequent passivation with layers containing hydrogen can lead to a decrease in the recombination strength to levels lower than in ungettered samples.

    The full text will be freely available from 2018-11-07 16:03
  • 15. Adams, Robin
    et al.
    Fischer, Sally
    Pears, Arnold
    Börstler, Jürgen
    Boustedt, Jonas
    Dalenius, Peter
    Eken, Gunilla
    Heyer, Tim
    Jacobsson, Andreas
    Lindberg, Vanja
    Molin, Bemgt
    Moström, Jan-Erik
    Wiggberg, Mattias
    What is the Word for "Engineering" in Swedisch: Swedish Students Conceptions of their Discipline2007Report (Refereed)
  • 16.
    Adamsson, Annika
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    En Montessori-inspirerad pedagogik utmanar högpresterande elever matematiskt: En kvalitativ studie om vilka strategier lärare som använder en Montessori- inspirerad pedagogik i årskurs 1-3 anser utmanar och stimulerar högpresterande elever i matematik.2016Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [sv]

    Studiens syfte var att ta reda på vilka strategier lärare som använder en Montessori-inspirerad pedagogik anser stimulerar och utmanar högpresterande elever i matematik samt om de upplevde några svårigheter eller problem med att undervisa högpresterande elever i matematik. För att undersöka det har sex kvalitativa intervjuer genomförts med lärare som har varit eller som är verksamma i årskurserna 1-3. Resultatet av intervjuerna visar att lärarna har en gemensam uppfattning om att en Montessori-inspirerad pedagogik utmanar och stimulerar högpresterande elever i matematik eftersom grundtanken i Montessori-pedagogiken är "eleven i centrum". Det här innebär att lärarna måste utgå från varje elevs förutsättningar, behov och aktuella kunskapsnivå. I resultatet framkommer också att lärarna använder sig av olika strategier i form av matematikbok från en högre årskurs, special- och fördjupningsområden, åldersintegrering och lärande med flera sinnen för att stimulera och utmana de högpresterande eleverna matematiskt. Det framgår också i resultatet att lärarna inte upplever några större problem eller svårigheter i undervisningen av högpresterande elever i matematik. De belyser ändå att den egna matematiska kompetensen, tidsbrist och eget kontrollbehov ibland kan utgöra hinder för att stimulera och utmana de högpresterande eleverna tillräckligt. Utifrån studien kan man dra slutsatserna att lärare som använder en Montessori-inspirerad pedagogik lägger stor vikt vid att hitta rätt strategi för rätt elev, vilket bidrar till att de högpresterande eleverna får utmaning och stimulans. De olika hindren som lärarna belyser skulle kunna minskas med fortbildning och samarbete mellan årskurserna. 

  • 17.
    Adamsson, Tim
    Karlstad University, Faculty of Arts and Social Sciences (starting 2013), Karlstad Business School.
    Kravrekommendation: En undersökning för kravrekommendationer för Nya Intranätets forum på Karlstad Universitet2014Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 18.
    Adolfsson, Oscar
    Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Effekter av inkuberingstemperatur hos juvenil atlantlax (Salmo salar L.)2018Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    Rising temperatures, because of climate change, will have major consequences for the world's fish populations, including the Atlantic salmon Salmo salar L. The greatest temperature changes are expected to occur during winter, which will affect S. salar since the eggs are developing during this time of year. Several studies have shown that elevated temperatures during embryogenesis cause morphological changes, in S. Salar, that are shown in later life stages. Some of these studies indicate that eggs incubated at high temperatures should generate parr with deeper bodies. To investigate whether high temperatures during the egg stage cause changes in body shape, parr from normal and high temperature incubated eggs, referred to as as “cold” and “warm” fish, respectively, were examined. A box-truss of euclidean distances between 10 landmarks on the fish body and a discriminant function analysis (DFA) was used to determine which of the distances best discriminated between the two groups. The test showed a significant discrimination between cold and warm parr regarding body shape where cold parr had greater heads and warm parr were deeper over the tail region and showed greater distances between the pelvic fin and the front attachment of the anal fin. 67,3 % of all parr where correctly classified by the test. These results support those notions that indicates that the incubation temperature is important for the morphological development of S. salar although it does not support the hypothesis.

  • 19. Adolfsson, Sandra
    Matematikverkstad: hur kan lärare och elever arbeta där?2010Student paper other, 10 credits / 15 HE creditsStudent thesis
    Abstract [en]

    The starting point of this work has been to get knowledge about teachers working in a mathematical workshop with the students. I also wanted to investigate what students think about math, both within the workshop and in traditional teaching.

    To achieve this I chose to interview a teacher in charge within the framework of a mathematical workshop, and six students in the 5th grade. I also did a lesson observation with the purpose to see how well the teacher’s tutoring agrees with the results of the interview.

    In this study I have discovered that the lessons in the mathematical workshop are planned after what the students are working with in the textbook. The teacher opens the lessons with the whole class and then splits it up in groups. In the interview the respondent conveys the importance of discussions among the students where they can explain their thoughts, especially for the weaker students that, thanks to the discussions are able to show their knowledge more. This is something I did not see during my lesson observation, however. The students also seemed to miss this when I spoke to them in the interview. They describe that they cannot see the connection between what they learn in the workshop and the textbook.

  • 20.
    Afzal, Zeeshan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Towards Secure Multipath TCP Communication2017Licentiate thesis, comprehensive summary (Other academic)
    Abstract [en]

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

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

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

  • 21.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Garcia, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Lindskog, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Partial Signature Matching in an MPTCP World using Insert-only Levenshtein DistanceManuscript (preprint) (Other academic)
    Abstract [en]

    This paper proposes a methodology consisting of a constrained version of the Levenshtein distance that can be used to detect signatures from partial traffic. The proposed algorithm is formally presented, implemented, and tested using the latest available version of the Snort ruleset. The results show that the algorithm can successfully detect all partial signatures with nearly 90% accuracy.

  • 22.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Garcia, Johan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Lindskog, Stefan
    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).
    Slice Distance: An Insert-Only Levenshtein Distance with a Focus on Security Applications2018In: Proceedings of NTMS 2018 Conference and Workshop, New York: IEEE, 2018, p. 1-5Conference paper (Refereed)
    Abstract [en]

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

  • 23.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Lindskog, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Automated Testing of IDS Rules2015In: Software Testing, Verification and Validation Workshops (ICSTW), 2015 IEEE Eighth International Conference on, IEEE conference proceedings, 2015Conference paper (Refereed)
    Abstract [en]

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

  • 24.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Lindskog, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    IDS rule management made easy2016In: Electronics, Computers and Artificial Intelligence (ECAI), 2016 8th International Conference on, IEEE conference proceedings, 2016Conference paper (Refereed)
    Abstract [en]

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

  • 25.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Lindskog, Stefan
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Multipath TCP IDS Evasion and Mitigation2015In: Information Security: 18th International Conference, ISC 2015, Trondheim, Norway, September 9-11, 2015, Proceedings, Springer, 2015, Vol. 9290, p. 265-282Conference paper (Refereed)
    Abstract [en]

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

  • 26.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Lindskog, Stefan
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science (from 2013).
    Brunström, Anna
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT.
    Lidén, Anders
    Towards Multipath TCP Aware Security Technologies2016In: 2016 8th IFIP International Conference onNew Technologies, Mobility and Security (NTMS), New York: IEEE, 2016, p. 1-8Conference paper (Refereed)
    Abstract [en]

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

  • 27.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Lindskog, Stefan
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Health, Science and Technology (starting 2013).
    Lidén, Anders
    A Multipath TCP Proxy2015Conference paper (Refereed)
    Abstract [en]

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

  • 28.
    Afzal, Zeeshan
    et al.
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Rossebø, Judith
    Integrated Operations, ABB AS, Norway.
    Chowdhury, Mohammad
    Talha, Batool
    ABB Corporate Research, ABB AS, Norway.
    A Wireless Intrusion Detection System for 802.11 networks2016In: PROCEEDINGS OF THE 2016 IEEE INTERNATIONAL CONFERENCE ON WIRELESS COMMUNICATIONS, SIGNAL PROCESSING AND NETWORKING (WISPNET), IEEE conference proceedings, 2016, p. 828-834Conference paper (Refereed)
    Abstract [en]

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

  • 29.
    Aguiño, Gonzalo Iglesias
    Karlstad University, Faculty of Economic Sciences, Communication and IT.
    Performance of VoIP strategies for hybrid Mobile Ad Hoc Networks2007Independent thesis Advanced level (degree of Magister), 20 points / 30 hpStudent thesis
    Abstract [en]

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

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

    in human’s daily life.

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

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

    infrastructure.

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

    field of wireless networking.

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

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

    This kind of networks is known as hybrid MANETs.

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

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

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

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

    quality.

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

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

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

    voice calls between MANET nodes and external nodes.

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

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

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

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

  • 30. Agustí, Ramón
    et al.
    Fazekas, Péter
    Gómez Barquero, David
    Lindskog, Stefan
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT.
    Oliver, Miquel
    Pérez-Romero, Jordi
    Tralli, Velio
    NEWCOM DR7.2: First report on common framework/models and activities in Department 72005Report (Refereed)
    Abstract [en]

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

  • 31. Agustí, Ramón
    et al.
    Fazekas, Péter
    Lindskog, Stefan
    Karlstad University, Faculty of Economic Sciences, Communication and IT, Department of Computer Science. Karlstad University, Faculty of Economic Sciences, Communication and IT, Centre for HumanIT.
    Oliver, Miquel
    Pérez-Romero, Jordi
    Studer Ferreira, Lucio
    Tralli, Velio
    NEWCOM DR7.4: Final Report on the activities carried out in Department 72007Report (Refereed)
    Abstract [en]

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

  • 32.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Finding lower bounds of localization with noisy measurements using genetic algorithms2011In: Proceedings of the first ACM international symposium on Design and analysis of intelligent vehicular networks and applications (DIVANet '11), Miami, Florida, USA: Association for Computing Machinery (ACM), 2011, p. 47-54Conference paper (Refereed)
    Abstract [en]

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

  • 33. Ahammed, Farhan
    et al.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Finding Lower Bounds of Localization with Noisy Measurements Using Genetic Algorithms2011Report (Refereed)
  • 34.
    Ahammed, Farhan
    et al.
    The University of Sydney, Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Using simulated annealing to find lower bounds of localization with noisy measurements2012In: 2012 IEEE 26th International Parallel and Distributed Processing Symposium Workshops & PhD Forum (IPDPSW), IEEE conference proceedings, 2012, p. 601-608Conference paper (Refereed)
  • 35.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    NICTA Australia Australian Technology Park.
    LICA: Improving Localization Given Noisy Data In GPS-Equipped VANETs Using Trilateration With Cluster Analysis2011Report (Refereed)
  • 36.
    Ahammed, Farhan
    et al.
    University of Sydney.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    NICTA.
    VLOCI: Using Distance Measurements to Improve the Accuracy of Location Coordinates in GPS-Equipped VANETs2012In: Mobile and Ubiquitous Systems: 7th International ICST Conference, MobiQuitous 2010, Sydney, Australia, December 6-9, 2010, Revised Selected Papers / [ed] Patrick Sénac, Max Ott, Aruna Seneviratne, Springer Berlin/Heidelberg, 2012, Vol. 73, p. 149-161Conference paper (Refereed)
  • 37.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    NICTA Australia Australian Technology Park.
    VLOCI2: An Iterative Method To Improve Location Coordinates In GPS-Equipped VANETs in Multiple Lanes2011Report (Refereed)
  • 38.
    Ahammed, Farhan
    et al.
    The University of Sydney, Australia.
    Taheri, Javid
    The University of Sydney, Australia.
    Zomaya, Albert
    The University of Sydney, Sydney, Australia.
    Ott, Max
    Australian Technology Park, Australia.
    VLOCI2: An Iterative Method To Improve Location Coordinates In GPS-Equipped VANETs in Multiple Lanes2011Report (Refereed)
  • 39.
    Ahlgren, Johan
    et al.
    Lund Univ, Dept Biol Aquat Ecol, S-22362 Lund, Sweden..
    Chapman, Ben B.
    Lund Univ, Dept Biol Aquat Ecol, S-22362 Lund, Sweden.;Univ Nottingham, Sch Life Sci, Nottingham NG7 2RD, England..
    Nilsson, Anders P.
    Bronmark, Christer
    Lund Univ, Dept Biol Aquat Ecol, S-22362 Lund, Sweden..
    Individual boldness is linked to protective shell shape in aquatic snails2015In: Biology Letters, ISSN 1744-9561, E-ISSN 1744-957X, Vol. 11, no 4, article id UNSP 20150029Article in journal (Refereed)
    Abstract [en]

    The existence of consistent individual differences in behaviour ('animal personality') has been well documented in recent years. However, how such individual variation in behaviour is maintained over evolutionary time is an ongoing conundrum. A well-studied axis of animal personality is individual variation along a bold-shy continuum, where individuals differ consistently in their propensity to take risks. A predation-risk cost to boldness is often assumed, but also that the reproductive benefits associated with boldness lead to equivalent fitness outcomes between bold and shy individuals over a lifetime. However, an alternative or complementary explanation may be that bold individuals phenotypically compensate for their risky lifestyle to reduce predation costs, for instance by investing in more pronounced morphological defences. Here, we investigate the 'phenotypic compensation' hypothesis, i.e. that bold individuals exhibit more pronounced anti-predator defences than shy individuals, by relating shell shape in the aquatic snail Radix balthica to an index of individual boldness. Our analyses find a strong relationship between risk-taking propensity and shell shape in this species, with bolder individuals exhibiting a more defended shell shape than shy individuals. We suggest that this supports the 'phenotypic compensation' hypothesis and sheds light on a previously poorly studied mechanism to promote the maintenance of personality variation among animals.

  • 40.
    Ahlin, Karin
    Karlstad University.
    Hur ser en fysiklaboration ut på lågstadiet?: En studie om hur lärare på lågstadiet arbetar på ett undersökande sätt i fysik.2018Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The purpose of this study was to find out how Primary school teachers work and think about the practical teaching in physics. Primary school teachers who work with a teacher support in science and technology, and Primary school teachers who do not work after any program have been interviewed. The method chosen in this study is semi-structured interview with sound recording. A total of seven interviews have been conducted and each interview took about 30 minutes to complete. The study addresses what research today says about practical activities in school and how the children learn the best way. Therefore, teachers are also asked about how they experience physics and practical work and how they choose to put an investigative approach. The result shows that the teachers experience physics as difficult and abstract. Teachers who work with a support program experience that the program helped them teach physics on a deeper level. The study also shows that most teachers uses closed and given labs.

  • 41. Aiki, T.
    et al.
    Hilhorst, D.
    Mimura, M.
    Muntean, Adrian
    Technische Universiteit Eindhoven, Department of Mathematics and Computer Science, Eindhoven, Netherlands .
    Preface2012In: Discrete and Continuous Dynamical Systems. Series S, ISSN 1937-1632, E-ISSN 1937-1179, discrete and cont, Vol. 5, no 1, p. 1-Article in journal (Refereed)
  • 42.
    Aiki, T.
    et al.
    Japan Womens Univ, Fac Sci, Dept Math, Bunkyo Ku, Tokyo.
    Hulshof, J.
    Vrije Univ Amsterdam, Fac Sci, Dept Math, Amsterdam, Netherlands.
    Kenmochi, N.
    Bukkyo Univ, Sch Educ Math, Kita Ku, Kyoto.
    Muntean, Adrian
    Eindhoven Univ Technol, Dept Math & Comp Sci,.
    Analysis of non-equilibrium evolution problems: Selected topics in material and life sciences2014In: Discrete and Continuous Dynamical Systems. Series S, ISSN 1937-1632, E-ISSN 1937-1179, Vol. 7, no 1Article in journal (Refereed)
  • 43. Aiki, T.
    et al.
    Muntean, Adrian
    Eindhoven Univ Technol, Dept Math & Comp Sci.
    A free-boundary problem for concrete carbonation: Front nucleation and rigorous justification of the root t-law of propagation2013In: Interfaces and free boundaries (Print), ISSN 1463-9963, E-ISSN 1463-9971, Vol. 15, no 2, p. 167-180Article in journal (Refereed)
  • 44. Aiki, T.
    et al.
    Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Existence and uniqueness of solutions to a mathematical model predicting service life of concrete structures2009In: Advances in Mathematical Sciences and Applications, ISSN 1343-4373, Vol. 19, p. 119-129Article in journal (Refereed)
  • 45.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Anthonissen, Martijn
    Eindhoven University Technology, Netherlands.
    Muntean, Adrian
    Eindhoven University Technology, Netherlands.
    On a one-dimensional shape-memory alloy model in its fast-temperature- activation limit2012In: Discrete and Continuous Dynamical Systems. Series S, ISSN 1937-1632, E-ISSN 1937-1179, Vol. 5, no 1, p. 15-28Article in journal (Refereed)
  • 46.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Muntean, Adrian
    Eindhoven University of Technology.
    Large time behavior of solutions to a moving-interface problem modeling concrete carbonation2010In: Communications on Pure and Applied Analysis, ISSN 1534-0392, E-ISSN 1553-5258, Vol. 9, no 5, p. 1117-1129Article in journal (Refereed)
  • 47.
    Aiki, Toyohiko
    et al.
    Tokyo Womens University.
    Muntean, Adrian
    Netherlands.
    Large-time asymptotics of moving-reaction interfaces involving nonlinear Henry’s law and time-dependent Dirichlet data2013In: Nonlinear Analysis, ISSN 0362-546X, E-ISSN 1873-5215, Vol. 93, p. 3-14Article in journal (Refereed)
    Abstract [en]

    We study the large-time behavior of the free boundary position capturing the one-dimensional motion of the carbonation reaction front in concrete-based materials. We extend here our rigorous justification of the t-behavior of reaction penetration depths by including nonlinear effects due to deviations from the classical Henry's law and time-dependent Dirichlet data.

  • 48. Aiki, Toyohiko
    et al.
    Muntean, Adrian
    Eindhoven University of Technology.
    Large-time behavior of a two-scale semilinear reaction-diffusion system for concrete sulfatation2014In: Mathematical methods in the applied sciences, ISSN 0170-4214, E-ISSN 1099-1476, Vol. 38, no 7, p. 1451-1464Article in journal (Refereed)
  • 49.
    Aiki, Toyohiko
    et al.
    Japan.
    Muntean, Adrian
    Karlstad University, Faculty of Health, Science and Technology (starting 2013), Department of Mathematics and Computer Science.
    Large-time behavior of solutions to a thermo-diffusion system with Smoluchowski interactions2017In: Journal of Differential Equations, ISSN 0022-0396, E-ISSN 1090-2732, Vol. 5, no 5, p. 3009-3026Article in journal (Refereed)
    Abstract [en]

    We prove the large time behavior of solutions to a coupled thermo-diffusion arising in the modeling of the motion of hot colloidal particles in porous media. Additionally, we also ensure the uniqueness of solutions of the target problem. The main mathematical difficulty is due to the presence in the right-hand side of the equations of products between temperature and concentration gradients. Such terms mimic the so-called thermodynamic Soret and Dufour effects. These are cross-coupling terms emphasizing in this context a strong interplay between heat conduction and molecular diffusion.

  • 50.
    Aiki, Toyohiko
    et al.
    Gifu University, Japan.
    Muntean, Adrian
    Eindhoven University of Technology.
    On uniqueness of a weak solution of one-dimensional concrete carbonation problem2011In: Discrete and Continuous Dynamical Systems, ISSN 1078-0947, E-ISSN 1553-5231, Vol. 29, no 4, p. 1345-1365Article in journal (Refereed)
    Abstract [en]

    In our previous works we studied a one-dimensional free-boundary model related to the aggressive penetration of gaseous carbon dioxide in unsaturated concrete. Essentially, global existence and uniqueness of weak solutions to the model were obtained when the initial functions are bounded on the domain. In this paper we investigate the well-posedness of the problem for the case when the initial functions belong to a  class. Specifically, the uniqueness of weak solutions is proved by applying the dual equation method.

1234567 1 - 50 of 5392
CiteExportLink to result list
Permanent link
Cite
Citation style
  • apa
  • harvard1
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Other style
More styles
Language
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Other locale
More languages
Output format
  • html
  • text
  • asciidoc
  • rtf