Change search
Refine search result
61626364656667 3151 - 3200 of 125184
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.
  • 3151. Akselsen, Odd M.
    et al.
    Aune, Ragnhild E.
    Olden, Vigdis
    Rorvik, Gisle
    Effects of phase transformations on residual stresses in welding of stainless steels2007In: International Journal of Offshore and Polar Engineering, ISSN 1053-5381, Vol. 17, no 2, p. 145-151Article in journal (Refereed)
    Abstract [en]

    In this investigation, we investigate the effects of solid state phase transformation on residual stresses in welding super-martensitic stainless steels, using the Satoh experimental test approach. The results obtained clearly demonstrate that the austenite-to-martensite phase transformation has remarkable effects on the final tensile residual stress level, and stresses as low as 70 to 170 MPa were found, depending on the weld thermal program. These results may imply that unnecessary conservatism is often used when assuming residual stresses to be of the same order as the base metal yield strength.

  • 3152. Akselsen, Odd M.
    et al.
    Fostervoll, Hans
    Harsvaer, Ansgar
    Aune, Ragnhild E.
    Weld metal mechanical properties in hyperbaric GTAW of X70 pipeline2006In: International Journal of Offshore and Polar Engineering, ISSN 1053-5381, Vol. 16, no 3, p. 233-240Article in journal (Refereed)
    Abstract [en]

    In the present investigation, 2 different wires for hyperbaric (underwater) GTA (gas tungsten arc) welding of X70 pipelines have been tested with respect to their weld metal mechanical properties. Welding of full coupons at different pressures (seawater depths of 16, 75 and 200 msw) was done with subsequent weld metal chemical analyses, hardness measurements, tensile testing and Charpy V notch testing as well as microstructure characterization. It is shown that both wires satisfied strength requirements set to X70 grade, representing a weld metal overmatch situation. Both wires gave sufficient impact toughness, but the toughness of the Ni-Mo containing weld was reduced with increasing seawater depth. This observation was strongly linked to the positioning of the Charpy V notch, and crack growth in a brittle, partially transformed region as a consequence of reheating by subsequent stringer beads. The embrittling microstructure consisted of high carbon MA (martensite-austenite constituents islands) decorating prior austenite grain boundaries. This microstructure was less pronounced when welding with the high Ni wire, which may explain why no similar toughness drop was found.

  • 3153.
    Aksjonova, Jevgenija
    KTH, School of Electrical Engineering and Computer Science (EECS).
    LDD: Learned Detector and Descriptor of Points for Visual Odometry2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Simultaneous localization and mapping is an important problem in robotics that can be solved using visual odometry -- the process of estimating ego-motion from subsequent camera images. In turn, visual odometry systems rely on point matching between different frames. This work presents a novel method for matching key-points by applying neural networks to point detection and description. Traditionally, point detectors are used in order to select good key-points (like corners) and then these key-points are matched using features extracted with descriptors. However, in this work a descriptor is trained to match points densely and then a detector is trained to predict, which points are more likely to be matched with the descriptor. This information is further used for selection of good key-points. The results of this project show that this approach can lead to more accurate results compared to model-based methods.

  • 3154. Aktas, A.
    et al.
    Ismail, Mohammed
    Pad de-embedding in RF CMOS2001In: IEEE Circuits & Devices, ISSN 8755-3996, E-ISSN 1558-1888, Vol. 17, no 3, p. 8-11Article in journal (Refereed)
    Abstract [en]

    Welcome to The Chip! We remain committed to bringing you material you can use in your work and research. We solicit your contributions and input on what we present here. Material or short articles on chip design tips, modeling and characterization techniques, yield enhancement, packaging, and test are welcome, as well as news on new chips and start-ups, mergers, acquisitions, partnerships in the microchip business, etc. Please continue to e-mail us at ismail@ee.eng.ohio-state.edu or ntan@globespan.net. In this column, we discuss techniques for RF pad layout and de-embedding, a topic of great interest particularly for implementing radio frequency (RF) circuits in mainstream CMOS technology. Happy reading!

  • 3155. Aktas, Adem
    et al.
    Jonsson, Fredrik
    KTH, School of Information and Communication Technology (ICT), Electronic Systems.
    Ahola, Rami
    Ismail, Mohammed
    A 4 Ghz 0.18um CMOS PLL Frequency Synthesizer withWide-Band VCO for Multi-Standard Wireless Applications2003In: Proc. 22nd Norchip Conference, 2003, p. 248-251Conference paper (Refereed)
  • 3156.
    Aktas, Bagsen
    et al.
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Bria, Aurelian
    KTH, Superseded Departments, Signals, Sensors and Systems.
    Evaluation of User Perceived Performance in Sparce Infrastructure Wireless Systems2004Conference paper (Refereed)
    Abstract [en]

    This work tries to evaluate the user perceived performance in a wireless system based on sparse infrastructure (islands of coverage).We investigate a mobile user in a Manhattan environment and the considered service is web browsing. Data caching in the use terminal is employed in order to hide the discontinuities of coverage. We show that for this particular application, the user's behavior of revisiting pages previously accessed makes caching a way to increase the user perceived coverage. Our results show that at low levels of effective area coverage caching brings a large improvement, while the gain is not significant at high levels. If the sparse coverage network is overlaid over a cellular system the obtained results show potential for significant cost savings.

  • 3157.
    Aktas, Meryem
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Anslin, Anslin
    KTH, School of Industrial Engineering and Management (ITM), Applied Mechanical Engineering (KTH Södertälje).
    Analys och utveckling avverifieringsenhet för säker kontakteringvid kalibrering av RRUS.2014Independent thesis Basic level (university diploma), 10 credits / 15 HE creditsStudent thesis
  • 3158.
    Aktas, O.
    et al.
    Univ Southampton, Optoelect Res Ctr, Southampton SO17 1BJ, Hants, England..
    Ren, H.
    Univ Southampton, Optoelect Res Ctr, Southampton SO17 1BJ, Hants, England..
    Runge, A. F. J.
    Univ Southampton, Optoelect Res Ctr, Southampton SO17 1BJ, Hants, England..
    Peacock, A. C.
    Univ Southampton, Optoelect Res Ctr, Southampton SO17 1BJ, Hants, England..
    Hawkins, T.
    Clemson Univ, COMSET, Clemson, SC 29634 USA.;Clemson Univ, Dept Mat Sci & Engn, Clemson, SC 29634 USA..
    Ballato, J.
    Clemson Univ, COMSET, Clemson, SC 29634 USA.;Clemson Univ, Dept Mat Sci & Engn, Clemson, SC 29634 USA..
    Gibson, U. J.
    KTH, School of Engineering Sciences (SCI), Applied Physics. Norwegian Univ Sci & Technol, Dept Phys, N-7491 Trondheim, Norway.
    Interfacing Telecom Fibers and Silicon Core Fibers with Nano-Spikes for In-Fiber Silicon Devices2018In: 2018 Optical Fiber Communications Conference and Exposition, OFC 2018 - Proceedings, Institute of Electrical and Electronics Engineers (IEEE), 2018Conference paper (Refereed)
    Abstract [en]

    We report fabrication of tapered silicon core fibers with nano-spikes enabling efficient optical coupling into the core, as well as their seamless integration with single mode fibers. A proof-of-concept integrated in-fiber silicon device is demonstrated.

  • 3159. Aktas, O.
    et al.
    Ren, H.
    Runge, A. F. J.
    Peacock, A. C.
    Hawkins, T.
    Ballato, J.
    Gibson, Ursula J.
    KTH, School of Engineering Sciences (SCI), Applied Physics.
    Interfacing telecom fibers and silicon core fibers with nano-spikes for in-fiber silicon devices2018In: Optics InfoBase Conference Papers, Optics Info Base, Optical Society of America, 2018, article id u12d3i3mConference paper (Refereed)
    Abstract [en]

    We report fabrication of tapered silicon core fibers with nano-spikes enabling efficient optical coupling into the core, as well as their seamless integration with single mode fibers. A proof-of-concept integrated in-fiber silicon device is demonstrated. © OSA 2018.

  • 3160.
    Aktas, Stefanos
    et al.
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    Wennhall, Thomas
    KTH, School of Industrial Engineering and Management (ITM), Machine Design (Dept.), Integrated Product Development.
    AI - an Untapped Opportunity for Innovation Developing a Screening Tool for AI and Innovation2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    It is known that innovation enables companies to penetrate new markets and achieve higher margins and that technology can contribute to achieving a competitive ad-vantage and growth for organizations. A technology that has as of recently grown to become relevant for organizations is Artificial Intelligence (AI). Even so, previous studies have expressed the difficulty of implementing AI, which motivated this study.

    The main purpose of this study was to develop and test a screening tool that will work as a support in increasing an organization’s utilization of AI and innovation capability. During the course of the study, a great amount of focus was also put into conducting a preliminary analysis in preparation for a larger study that will be dependent on gathering large amounts of quantitative data.

    The research took on a three-phase-process. The first phase focused on gaining basic knowledge in regards to AI, innovation, technology management and model development. The findings in the first phase helped to formulate proper research questions that were applicable to the study.

    After that, the study moved on to the second phase which focused on a more in-depth literature study. This then led on to the development of an appropriate questionnaire for investigating factors that are relevant for AI and innovation, and an assessment model that would be connected to the questionnaire. The questionnaire was used for gathering responses that would be beneficial for the preliminary analysis in the form of a pilot study. The questionnaire and the assessment model together form a screening tool that gives a visual output of an organization’s position in regards to AI and innovation.

    The third and final phase included testing of the created screening tool, analyzing the findings from the pilot study and drawing conclusions from both the developed screening tool, and the results from the pilot study.

    The result from the literature study was the screening tool which takes five di-mensions into consideration that shows relevance to AI and innovation. These di-mensions are Structures, Resources, Methods, Action and Business,eachcontaining areas that exist in organizations that can be adjusted for the sake of the implemen-tation of AI and improvement of innovation management. The screening tool was tested on two separate organizations and managed to reflect these organizations’ AI progress through the assessment model. The screening tool was also applied to the pilot study which resulted in giving indications of what to expect when conducting a larger quantitative study.

    Despite the results gained from this study, it showed that further tests and studies need to be made in order to obtain more viable results. This study will act as a guideline for future studies to attain those results.

  • 3161. Akter, Farhima
    et al.
    Mie, Masayasu
    Grimm, Sebastian
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Nygren, Per-Åke
    KTH, School of Biotechnology (BIO), Molecular Biotechnology.
    Kobatake, Eiry
    Detection of Antigens Using a Protein-DNA Chimera Developed by Enzymatic Covalent Bonding with phiX Gene A2012In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 84, no 11, p. 5040-5046Article in journal (Refereed)
    Abstract [en]

    The chemical reactions used to make antibody DNA conjugates in many immunoassays diminish antigen-binding activity and yield heterogeneous products. Here, we address these issues by developing an antibody-based rolling circle amplification (RCA) strategy using a fusion of phi X174 gene A* protein and Z(mab2s) (A*-Zmab). The phi X174 gene A* protein is an enzyme that can covalently link with DNA, while the Z(mab2s) protein moiety can bind to specific species of antibodies. The DNA in an A*-Zmab conjugate was attached to the A* protein at a site chosen to not interfere with protein function, as determined by enzyme-linked immunosorbent assay (ELISA) and gel mobility shift analysis. The novel A*-Zmab-DNA conjugate retained its binding capabilities to a specific class of murine immunoglobulin gamma 1 (IgG1) but not to rabbit IgG. This indicates the generality of the A*-Zmab-based immuno-RCA assay that can be used in-sandwich ELISA format. Moreover, the enzymatic covalent method dramatically increased the yields of A*-Zmab-DNA conjugates up to 80% after a 15 min reaction. Finally, sensitive detection of human interferon-gamma (IFN-gamma) was achieved by immuno-RCA using our fusion protein in sandwich ELISA format. This new approach of the use of site-specific enzymatic DNA conjugation to proteins should be applicable to fabrication of novel immunoassays for biosensing.

  • 3162.
    Akter, Nasrin
    KTH, School of Industrial Engineering and Management (ITM), Energy Technology, Energy and Climate Studies, ECS.
    Energy Need Assessment and Preferential Choice Survey o fMatipukur Village in Bangladesh: Energy Need Assessment and Preferential Choice Survey of Rural People in Bangladesh2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    The aim of this study is to perform a baseline energy survey to understand the existing energy demand and usepattern and to verify the feasibility of a small scale poly-generation project supported by renewable sources ofenergy (biogas based) in a rural area of Bangladesh. A poly-generation solution shall provide multiple outputservices of clean gas, electricity and arsenic free water supply. The project requires using animal dung oragricultural waste to produce biogas and electric energy. The study has analyzed the demand of domesticenergy and water of the village named ‘Matipukur’ in the Jessore district in Bangladesh. The study alsoconsidered available biomass feedstock and energy potential surrounding the village area, as well as the socioeconomicstatus of villagers. The case study included a door to door survey to collect relevant information.Three different economic groups in terms of income scale were investigated throughout the study to obtainbetter insight of the energy-water access situation, requirements and related problems in the village.

    Almost 98% household of this village relies on biomass for energy due to limited access of modern fuel. Thevillage has various biomass potential in the form of animal dung, fuel wood and agricultural waste which can beused for cooking or serve as the basis for other energy carriers. Kerosene is used for lighting. Among thedifferent fuels, dung meets about 44% of the total demand. The contribution of other fuels for domestic use is24% firewood, 22% agricultural waste, and 2% kerosene. The analytical observation found that the annualaverage energy demand of the village is 8.45 GJ per capita. The share of average demand for cooking and3lighting energy is 8.24 GJ per person/year and 0.21 GJ per person/year respectively. The energy consumptionvaries within different income groups. This study has examined the income per capita, family size, education,agricultural land holding per capita, priorities of their annual expenditure etc. which have direct influence onthe fuel consumption pattern of the household. It could be observed that expenses on energy changes as theincome level increases. About awareness of biogas opportunities and willingness to provide feedstock for apoly generation project, the majority of households answered positively, that is, indicating that they wouldcontribute. Educated respondents showed more positive attitude. Regarding changing of traditional cooking,about 95% of the respondents want to change to a more efficient and reliable cooking system to avoid healthand environmental problems associated with indoor biomass cooking.

    The study has revealed that only cow dung is not enough to produce clean energy according to demand so theco-digestion method is considered to producing biogas from various energy potentials (animal manure &agricultural waste). The poly-generation system could work with the scenario providing electricity and watersupply for the entire household and cooking gas is limited only for 2/3rd household. Rest 1/3rd household fromlow income group then could be supplied with improve cook stove to meet their daily cooking demand and tominimize indoor pollutions. It is observed that, majority of household has expressed their willingness toprovide raw materials for poly-generation plant though they are using.

  • 3163.
    Aktug, Irem
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Algorithmic Verification Techniques for Mobile Code2008Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    Modern computing platforms strive to support mobile code without putting system security at stake. These platforms can be viewed as open systems, as the mobile code adds new components to the running system. Establishing that such platforms function correctly can  be divided into two steps. First, it is shown that the system functions correctly regardless of the mobile components that join it, provided that they satisfy certain assumptions. These assumptions can, for instance, restrict the behavior of the component to ensure that the security policy of the platform is not violated. Second, the mobile component is checked to satisfy its assumptions, before it is allowed to join the system. This thesis presents algorithmic verification techniques to support this methodology. In the first two parts, we present techniques for the verification of open systems relative to the given component assumptions. In the third part, a technique for the  quick certification of mobile code is presented for the case where a particular type of program rewriting is used as a means of enforcing the component assumptions.In the first part of this study, we present a framework for the verification of open systems based on explicit state space representation. We propose Extended Modal Transition Systems (EMTS) as a suitable structure for representing the state space of open systems when assumptions on components are written in the modal μ-calculus. EMTSs are based on the Modal Transition Systems (MTS) of Larsen and provide a formalism for graphical specification and facilitate a thorough understanding of the system by visualization. In interactive verification, this state space representation enables proof reuse and aids the user guiding the verification process. We present a construction of state space representations from process algebraic open system descriptions based on a maximal model construction for the modal μ-calculus. The construction is sound and complete for systems with a single unknown component and sound for those without dynamic process reation. We also suggest a tableau-based proof system for establishing temporal properties of open systems represented as EMTS. The proof system is sound in general and complete for prime formulae.The problem of open system correctness  also arises in compositional verification, where the problem of showing a global property of a system is reduced to showing local properties of components. In the second part, we extend an existing  compositional verification framework for Java bytecode programs. The framework employs control flow graphs with procedures to model component implementations and open systems for the purpose of checking control-flow properties. We generalize these models to capture exceptional and multi-threaded behavior. The resulting control flow graphs are specifically tailored to support the compositional verification principle; however, they are sufficiently intuitive and standard to be useful on their own. We describe how the models can be extracted from program code and give preliminary experimental results for our implementation of the extraction of control flow graphs with exceptions. We also discuss further tool support and practical applications of the method.In the third part of the thesis, we develop a technique for the certification of safe mobile code, by adapting the proof-carrying code scheme of Necula to the case of security policies expressed as security automata. In particular, we describe how proofs of policy compliance can  be automatically generated for  programs that include a monitor for the desired policy. A monitor is an entity that observes the execution of a program and terminates the program if a violation to the property is about to occur. One way to implement such a monitor is by rewriting the program to make it self-monitoring. Given a property, we characterize self-monitoring of Java bytecode programs for this property by an annotation scheme with annotations in the style of Floyd-Hoare logics. The annotations generated by this scheme can be extended in a straightforward way to form a correctness proof in the sense of axiomatic semantics of programs. The proof generated in this manner essentially establishes that the program satisfies the property because it contains a monitor for it. The annotations that comprise the proofs are simple and efficiently checkable, thus facilitate certification of mobile code on devices with restricted computing power such as mobile phones.

  • 3164.
    Aktug, Irem
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    State space representation for verification of open systems2006Licentiate thesis, monograph (Other scientific)
    Abstract [en]

    When designing an open system, there might be no implementation available for cer- tain components at verification time. For such systems, verification has to be based on assumptions on the underspecified components. In this thesis, we present a framework for the verification of open systems through explicit state space representation.

    We propose Extended Modal Transition Systems (EMTS) as a suitable structure for representing the state space of open systems when assumptions on components are writ- ten in the modal μ-calculus. EMTSs are based on the Modal Transition Systems (MTS) of Larsen. This representation supports state space exploration based verification tech- niques, and provides an alternative formalism for graphical specification. In interactive verification, it enables proof reuse and facilitates visualization for the user guiding the verification process.

    We present a two-phase construction from process algebraic open system descriptions to such state space representations. The first phase deals with component assumptions, and is essentially a maximal model construction for the modal μ-calculus that makes use of a powerset construction for the fixed point cases. In the second phase, the models obtained are combined according to the structure of the open system to form the complete state space. The construction is sound and complete for systems with a single unknown component and sound for those without dynamic process creation. We suggest a tableau-based proof system for establishing open system properties of the state space representation. The proof system is sound and it is complete for modal μ-calculus formulae with only prime subformulae.

    A complete framework based on the state space representation is offered for the auto- matic verification of open systems. The process begins with specifying the open system by a process algebraic term with assumptions. Then, the state space representation is ex- tracted from this description using the construction described above. Finally, open system properties can be checked on this representation using the proof system.

  • 3165.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Dam, Mads
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Provably Correct Runtime Monitoring2009In: Journal of Logic and Algebraic Programming, ISSN 1567-8326, E-ISSN 1873-5940, Vol. 78, no 5, p. 304-339Article in journal (Refereed)
    Abstract [en]

    Runtime monitoring is an established technique to enforce a wide range of program safety and security properties. We present a formalization of monitoring and monitor inlining, for the Java Virtual Machine. Monitors are security automata given in a special-purpose monitor specification language, ConSpec. The automata operate on finite or infinite strings of calls to a fixed API, allowing local dependencies on parameter values and heap content. We use a two-level class file annotation scheme to characterize two key properties: (i) that the program is correct with respect to the monitor as a constraint on allowed program behavior, and (ii) that the program has a copy of the given monitor embedded into it. As the main application of these results we sketch a simple inlining algorithm and show how the two-level annotations can be completed to produce a fully annotated program which is valid in the standard sense of Floyd/Hoare logic. This establishes the mediation property that inlined programs are guaranteed to adhere to the intended policy. Furthermore, validity can be checked efficiently using a weakest precondition based annotation checker, thus preparing the ground for on-device checking of policy adherence in a proof-carrying code setting.

  • 3166.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Dam, Mads
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Provably correct runtime monitoring (extended abstract)2008In: Fm 2008: Formal Methods, Proceedings / [ed] Cuellar, J; Maibaum, T; Sere, K, 2008, Vol. 5014, p. 262-277Conference paper (Refereed)
    Abstract [en]

    Runtime monitoring is an established technique for enforcing a wide range of program safety and security properties. We present a formalization of monitoring and monitor inlining, for the Java Virtual Machine. Monitors are security automata given in a special-purpose monitor specification language, ConSpec. The automata operate on finite or infinite strings of calls to a fixed API, allowing local dependencies on parameter values and heap content. We use a two-level class file annotation scheme to characterize two key properties: (i) that the program is correct with respect to the monitor as a constraint on allowed program behavior, and (ii) that the program has an instance of the given monitor embedded into it, which yields state changes at prescribed points according to the monitor's transition function. As our main application of these results we describe a concrete inliner, and use the annotation scheme to characterize its correctness. For this inliner, correctness of the level II annotations can be decided efficiently by a weakest precondition annotation checker, thus allowing on-device checking of inlining correctness in a proof-carrying code setting.

  • 3167.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Numerical Analysis and Computer Science, NADA.
    State Space Representation for Verification of Open Systems2006In: Algebraic Methodology And Software Technology, Proceedings / [ed] Johnson, M; Vene, V, Berlin: Springer , 2006, p. 5-20Conference paper (Refereed)
    Abstract [en]

    When designing an open system, there might be no implementation available for certain components at verification time. For such systems, verification has to be based on assumptions on the underspecified components. When component assumptions are expressed in Hennessy-Milner logic (HML), the state space of open systems can be naturally represented with modal transition systems (NITS), a graphical specification language equiexpressive with HML. Having an explicit state space representation supports state space exploration based verification techniques, Besides, it enables proof reuse and facilitates visualization for the user guiding the verification process. in interactive verification. As an intuitive representation of system behavior, it aids debugging when proof generation fails in automatic verification.

    However, HML is not expressive enough to capture temporal assumptions. For this purpose, we extend MTSs to represent the state space of open systems where component assumptions are specified in modal mu-calculus. We present a two-phase construction from process algebraic open system descriptions to such state space representations. The first phase deals with component assumptions, and is essentially a maximal model construction for the modal p-calculus. In the second phase, the models obtained are combined according to the structure of the open system to form the complete state space. The construction is sound and complete for systems with a single unknown component and sound for those-without dynamic process creation. For establishing open system properties based on the representation, we present a proof system which is sound and complete for prime formulae.

  • 3168.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Gurov, Dilian
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Towards State Space Exploration Based Verification of Open Systems2005In: 4th International Workshop on Automated Verification of Infinite-State Systems (AVIS’05), April 2005, Edinburgh, Scotland, 2005Conference paper (Refereed)
  • 3169.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Naliuka, Katsiaryna
    University of Trento, Italy.
    ConSpec: A Formal Language for Policy Specification2008In: Science of Computer Programming, ISSN 0167-6423, E-ISSN 1872-7964, Vol. 74, no 1-2, p. 2-12Article in journal (Refereed)
    Abstract [en]

    The paper presents ConSpec, an automata-based policy specification language. The language trades off clean semantics to language expressiveness: a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various Policy enforcement techniques.

  • 3170.
    Aktug, Irem
    et al.
    KTH, School of Computer Science and Communication (CSC), Theoretical Computer Science, TCS.
    Naliuka, Katsiaryna
    University of Trento, Italy.
    ConSpec: A Formal Language for Policy Speci-fication2007In: Proceedings of The First International Workshop on Run Time Enforcement for Mobile and Distributed Systems (REM’07), 2007, p. 45-58Conference paper (Other academic)
    Abstract [en]

    The paper presents ConSpec, an automata based policy specification language. The language trades off clean semantics to language expressiveness; a formal semantics for the language is provided as security automata. ConSpec specifications can be used at different stages of the application lifecycle, rendering possible the formalization of various policy enforcement techniques.

  • 3171. Akulich, A
    et al.
    Isacsson, Ulf
    KTH, School of Architecture and the Built Environment (ABE), Transport Science, Highway and Railway Engineering.
    Laboratorieundersökningar av åldringsegenskaper hos dränerande asfaltbetong1992Report (Other academic)
  • 3172. Akyol, Z
    et al.
    Arbaugh, B
    Cleveland-Innes, Marta
    KTH, School of Computer Science and Communication (CSC), Media Technology and Graphic Arts, Media (closed 20111231).
    Garrison, R
    Ice, P
    Richardson, J
    Swan, K
    A response to the review of the community of inquiry framework2009In: Journal of distance education = Revue de l'enseignement à distance, ISSN 1916-6818, Vol. 23, no 2, p. 123-136Article in journal (Refereed)
    Abstract [en]

    The Community of Inquiry (CoI) framework has become a prominent model of teaching and learning in online and blended learning environments. Considerable research has been conducted which employs the framework with promising results, resulting in wide use to inform the practice of online and blended teaching and learning. For the CoI model to continue to grow and evolve, constructive critiques and debates are extremely beneficial, in so much as they identify potential problems and weaknesses in the model or its application, as well as provide direction for further research. In this context, the CoI framework was recently reviewed and critiqued by Rourke and Kanuka in their JDE article entitled “Learning in Communities of Inquiry: A Review of the Literature.” This paper is a response to this article and focuses on two main issues. The first issue is the focus of the review and critique on learning outcomes. The second issue concerns the representation, comprehensiveness, and methodology of the review.

  • 3173.
    Akçay, H.
    et al.
    Linköping University.
    Hjalmarsson, Håkan
    Linköping University.
    The Least-Squares Identification of FIR Systems Subject to Worst-Case Noise1994In: 10th IFAC Symposium on System Identification, 1994, Vol. 2, p. 85-90Conference paper (Refereed)
  • 3174.
    Akçay, H.
    et al.
    Linköping University.
    Hjalmarsson, Håkan
    Linköping University.
    The least-squares identification of FIR systems subject to worst-case noise1994In: System & Control Letters, Vol. 23, p. 329-338Article in journal (Refereed)
  • 3175.
    Akçay, H.
    et al.
    Linköping University.
    Hjalmarsson, Håkan
    Linköping University.
    Ljung, Lennart
    Department of Electrical Engineering, Linköping University.
    On the choice of norms i system identification1994In: 10th IFAC Symposium on System Identification, 1994, Vol. 2, p. 103-108Conference paper (Refereed)
  • 3176.
    Al Abassi, Mohammed
    KTH, School of Architecture and the Built Environment (ABE), Urban Planning and Environment, Urban and Regional Studies.
    The Possibilities for Establishing Agricultural Vocational Training Institutions in Kisumu2012Independent thesis Basic level (degree of Bachelor), 10 credits / 15 HE creditsStudent thesis
  • 3177.
    Al Ahad, Muhammed Abdullah
    et al.
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Simmendinger, Christian
    T Syst Solut Res GmbH, D-70563 Stuttgart, Germany..
    Iakymchuk, Roman
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Laure, Erwin
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Markidis, Stefano
    KTH, School of Electrical Engineering and Computer Science (EECS), Centres, Centre for High Performance Computing, PDC.
    Efficient Algorithms for Collective Operations with Notified Communication in Shared Windows2018In: PROCEEDINGS OF PAW-ATM18: 2018 IEEE/ACM PARALLEL APPLICATIONS WORKSHOP, ALTERNATIVES TO MPI (PAW-ATM), IEEE , 2018, p. 1-10Conference paper (Refereed)
    Abstract [en]

    Collective operations are commonly used in various parts of scientific applications. Especially in strong scaling scenarios collective operations can negatively impact the overall applications performance: while the load per rank here decreases with increasing core counts, time spent in e.g. barrier operations will increase logarithmically with the core count. In this article, we develop novel algorithmic solutions for collective operations such as Allreduce and Allgather(V)-by leveraging notified communication in shared windows. To this end, we have developed an extension of GASPI which enables all ranks participating in a shared window to observe the entire notified communication targeted at the window. By exploring benefits of this extension, we deliver high performing implementations of Allreduce and Allgather(V) on Intel and Cray clusters. These implementations clearly achieve 2x-4x performance improvements compared to the best performing MPI implementations for various data distributions.

  • 3178.
    Al Alam, Assad
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Optimally Fuel Ecient Speed Adaptation2008Independent thesis Advanced level (professional degree), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An optimal velocity trajectory for a heavy duty vehicle, obtained with the aid of modern GPS and digital map devices, depends on several variables. Curvature speed limitations, road grade, and posted road speed are common constraints imposed by the road travelled. This thesis presents a method for modelling and analysing a switching controller through the use of the former mentioned constraints. A non-linear model for the heavy duty vehicle is derived, enabling suitable control methods to be applied. Pontryagin’s Principal and LQR are discussed to get a profound understanding of how the controller should be designed. It is discovered that a switching controller based on optimal control and engineering experience is most favourable for the problem at hand. The controller is designed to address the main objectives set in this paper of minimising fuel consumption, travelling time, and brake wear.

    Gauss-Newtons’s algorithm for non-linear equations is used to estimate curve radii. Other input parameters are presumed to be available. GPS data error is discussed to perform a sensitivity analysis. An electronic horizon is produced on three road segments, entailed with data of the future road topology. Finally the switching controller is applied to the road segments. Experimental results show that the controller produces a velocity trajectory, which reduces fuel consumption by 5-15% and brake wear by 15-35%, while the travelling time is only increased by 1-2%.

  • 3179.
    Al Alam, Assad
    et al.
    Scania CV AB.
    Gattami, Ather
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, School of Electrical Engineering (EES), Automatic Control. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    An experimental study on the fuel reduction potential of heavy duty vehicle platooning2010In: 13th International IEEE Conference on Intelligent Transportation Systems (ITSC), 2010, IEEE , 2010, p. 306-311Conference paper (Refereed)
    Abstract [en]

    Vehicle platooning has become important for the vehicle industry. Yet conclusive results with respect to the fuel reduction possibilities of platooning remain unclear. The focus in this study is the fuel reduction that heavy duty vehicle platooning enables and the analysis with respect to the influence of a commercial adaptive cruise control on the fuel consumption. Experimental results show that by using preview information of the road ahead from the lead vehicle, the adaptive cruise controller can reduce the fuel consumption. A study is undertaken for various masses of the lead vehicle. The results show that the best choice with respect to a heavier or lighter lead vehicle depends on the desired time gap. A maximum fuel reduction of 4.7-7.7% depending on the time gap, at a set speed of 70 km/h, can be obtained with two identical trucks. If the lead vehicle is 10 t lighter a corresponding 3.8-7.4% fuel reduction can be obtained depending on the time gap. Similarly if the lead vehicle is 10 t heavier a 4.3-6.9% fuel reduction can be obtained. All results indicate that a maximum fuel reduction can be achieved at a short relative distance, due to both air drag reduction and suitable control.

  • 3180.
    Al Alam, Assad
    et al.
    KTH, School of Electrical Engineering (EES), Automatic Control.
    Gattami, Ather
    Electrical Engineering and Computer Sciences, UC Berkeley, Berkeley CA, 94720-1770, United States .
    Johansson, Karl Henrik
    Electrical Engineering and Computer Sciences, UC Berkeley, Berkeley CA, 94720-1770, United States .
    Tomlin, Claire Jennifer
    Scania CV AB, Södertälje, Sweden.
    Establishing safety for heavy duty vehicle platooning: a game theoretical approach2011In: IFAC Proceedings Volumes (IFAC-PapersOnline), 2011, p. 3818-3823Conference paper (Refereed)
    Abstract [en]

    It is fuel efficient to minimize the relative distance between vehicles to achievea maximum reduction in air drag. However, the relative distance can only be reduced to acertain extent without endangering a collision. Factors such as the vehicle velocity, the relativevelocity, and the characteristics of the vehicle ahead has a strong impact on what minimumrelative distance can be obtained. In this paper, we utilize optimal control and game theory toestablish safety criteria for heavy duty vehicle platooning applications. The derived results showthat a minimum relative distance of 1.2m can be obtained for two identical vehicles withoutendangering a collision, assuming that there is no delay present in the feedback system. If aworst case delay is present in the system, a minimum relative distance is deduced based uponthe vehicle’s maximum deceleration ability. The relative distance can be reduced if the followervehicle has a greater overall braking capability, which suggests that vehicle heterogeneity andorder has substantial impact. The findings are verified by simulations and the main conclusion isthat the relative distance utilized in commercial applications today can be reduced significantlywith a suitable advanced cruise control system.

  • 3181. Al Alawai, Reem
    et al.
    Laxman, karthik
    Dastgir, Sarim
    Dutta, Joydeep
    KTH, School of Information and Communication Technology (ICT), Materials- and Nano Physics, Functional Materials, FNM. Sultan Qaboos University, , Oman.
    Role of bonding mechanisms during transfer hydrogenation reaction on heterogeneous catalysts of platinum nanoparticles supported on zinc oxide nanorods2016In: Applied Surface Science, ISSN 0169-4332, E-ISSN 1873-5584, p. 200-206Article in journal (Refereed)
    Abstract [en]

    For supported heterogeneous catalysis, the interface between a metal nanoparticle and the support plays an important role. In this work the dependency of the catalytic efficiency on the bonding chemistry of platinum nanoparticles supported on zinc oxide (ZnO) nanorods is studied. Platinum nanoparticles were deposited on ZnO nanorods (ZnO NR) using thermal and photochemical processes and the effects on the size, distribution, density and chemical state of the metal nanoparticles upon the catalytic activities are presented. The obtained results indicate that the bonding at Pt-ZnO interface depends on the deposition scheme which can be utilized to modulate the surface chemistry and thus the activity of the supported catalysts. Additionally, uniform distribution of metal on the catalyst support was observed to be more important than the loading density. It is also found that oxidized platinum Pt(IV) (platinum hydroxide) provided a more suitable surface for enhancing the transfer hydrogenation reaction of cyclohexanone with isopropanol compared to zero valent platinum. Photochemically synthesized ZnO supported nanocatalysts were efficient and potentially viable for upscaling to industrial applications.

  • 3182.
    Al Baghdady, Shayma
    et al.
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Khan, Linnea
    KTH, School of Architecture and the Built Environment (ABE), Civil and Architectural Engineering, Concrete Structures.
    Designing Roller compacted concrete (RCC) dams2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Concrete is the most common building material in the world and it consists of aggregates,cement and water that harden over time, it is also known as a composite material. The use ofconcrete is very versatile due to its resistance to wind and water and its ability to withstandhigh temperature. These qualities make concrete a suitable building material for largestructures such as dams.A dam is a huge construction that needs massive amount of concrete to build it with and thatleads to high cost, so alternative methods should be considered to minimize the cost ofconstructing the dams. One method is building the dams with Roller Compacted Concrete(RCC), which by definition is a composite construction material with no-slump consistency inits unhardened state and it has achieved its name from the construction method. The definitionfor a no-slump consistency is a freshly mixed concrete with a slump less than 6 mm. TheRCC is placed with the help of paving equipment and then it is compacted by vibrating rollerequipment. The RCC ingredients are the same as for the conventional concrete but it hasdifferent ratios in the materials that are blended to produce the concrete. It differs when itcomes to aggregates because both similar aggregates used in conventional concrete oraggregates that do not fulfill the normal standards can be used in the RCC mixtures. Thismeans, for example that aggregates found on the construction site can be used for the RCC.Compared to when constructing a conventional concrete dam, which is usually built in largeblocks, the RCC dam are usually built in thin, horizontal lifts, which allows rapidconstruction. This reduces the amount of formwork, but also the demand for man-hours areless due to the usage of machines for spreading and compacting, ultimately making it acheaper method. Building with RCC has become very popular around the world because of itsadvantages and new methods have been developed over the past two decades, adapted to theexperience gained after each project. All RCC dams that has been built, usually faceschallenges both during and after construction, and it includes everything from temperaturevariations, cracks to leakage.The main purpose of this master thesis is to create a guideline for how to design and constructdams with RCC and the idea is to be able to use it as a basis for future dams. Therequirements of Eurocode 2 and RIDAS are the basis of the criteria that the dam must fulfilland information of what is expected of the RCC is presented in this thesis. Furthermore anexample for design of an existing embankment dam to an RCC dam has been presented in thisthesis. The embankment dam needs to be rebuilt in order to increase the safety of the dam andthe goal of the case study was to determine the dimensions of the new RCC dam.

  • 3183.
    Al Dakkak, O.
    et al.
    Higher Institute of Applied Sciencenand Technology (HIAST).
    Ghneim, N.
    Higher Institute of Applied Sciencenand Technology (HIAST).
    Abou Zliekha, M.
    Damascus University/Faculty of Information Technology.
    Al Moubayed, Samer
    Damascus University/Faculty of Information Technology.
    Emotional Inclusion in An Arabic Text-To-Speech2005In: Proceedings of the 13th European Signal Processing Conference (EUSIPCO), Antalya, Turkey, 2005Conference paper (Refereed)
    Abstract [en]

    The goal of this paper is to present an emotional audio-visua lText to speech system for the Arabic Language. The system is based on two entities: un emotional audio text to speech system which generates speech depending on the input text and the desired emotion type, and un emotional Visual model which generates the talking heads, by forming the corresponding visemes. The phonemes to visemes mapping, and the emotion shaping use a 3-paramertic face model, based on the Abstract Muscle Model. We have thirteen viseme models and five emotions as parameters to the face model. The TTS produces the phonemes corresponding to the input text, the speech with the suitable prosody to include the prescribed emotion. In parallel the system generates the visemes and sends the controls to the facial model to get the animation of the talking head in real time.

  • 3184.
    Al Dakkak, O.
    et al.
    HIAST, Damascus, Syria.
    Ghneim, N.
    HIAST, Damascus, Syria.
    Abou Zliekha, M.
    Damascus University.
    Al Moubayed, Samer
    Damascus University.
    Prosodic Feature Introduction and Emotion Incorporation in an Arabic TTS2006In: Proceedings of IEEE International Conference on Information and Communication Technologies, Damascus, Syria, 2006, p. 1317-1322Conference paper (Refereed)
    Abstract [en]

    Text-to-speech is a crucial part of many man-machine communication applications, such as phone booking and banking, vocal e-mail, and many other applications. In addition to many other applications concerning impaired persons, such as: reading machines for blinds, talking machines for persons with speech difficulties. However, the main drawback of most speech synthesizers in the talking machines, are their metallic sounds. In order to sound naturally, we have to incorporate prosodic features, as close as possible to natural prosody, this helps to improve the quality of the synthetic speech. Actual researches in the world are towards better "automatic prosody generation".

  • 3185.
    al Ghatta, Amir
    KTH, School of Biotechnology (BIO).
    Matematisk modellering och analys av en ny process för metantillvaratagande2015Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
  • 3186.
    Al Ghifary, Haider
    KTH, School of Architecture and the Built Environment (ABE), Architecture.
    Hötorget Rooftop Hälsocenter & Restaurang - en takpotential2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    An investigation of a rooftop potential of Hötorget Building 5 in Stockholm.

    This project proposes a program on floor 17, 18 and 19 (rooftop level) of the high-rise building containing a restaurant and a health centre with fitness facilities, group training and hamam-inspired steam sauna.

    The challenges have been to fit in a program in a space traditionally meant only for office use. The aim has been to provide a business that is useful for the place but at the same time provide architectural qualities by structural alterations to make vertical spaces with skylight, maximizing sightlines, keeping constant access to the façade and thereby access to the view outside. Other aims have been to create a brand and identity by adding an oriental hamam-theme into the project. Lastly the project intended to catch the “natural qualities” that are offered by a place of this height by giving access to the roof-top and letting the visitor experience the open sky and the city panorama throughout the year.

  • 3187.
    Al Hakim, Ezeddin
    KTH, School of Electrical Engineering and Computer Science (EECS).
    3D YOLO: End-to-End 3D Object Detection Using Point Clouds2018Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    For safe and reliable driving, it is essential that an autonomous vehicle can accurately perceive the surrounding environment. Modern sensor technologies used for perception, such as LiDAR and RADAR, deliver a large set of 3D measurement points known as a point cloud. There is a huge need to interpret the point cloud data to detect other road users, such as vehicles and pedestrians.

    Many research studies have proposed image-based models for 2D object detection. This thesis takes it a step further and aims to develop a LiDAR-based 3D object detection model that operates in real-time, with emphasis on autonomous driving scenarios. We propose 3D YOLO, an extension of YOLO (You Only Look Once), which is one of the fastest state-of-the-art 2D object detectors for images. The proposed model takes point cloud data as input and outputs 3D bounding boxes with class scores in real-time. Most of the existing 3D object detectors use hand-crafted features, while our model follows the end-to-end learning fashion, which removes manual feature engineering.

    3D YOLO pipeline consists of two networks: (a) Feature Learning Network, an artificial neural network that transforms the input point cloud to a new feature space; (b) 3DNet, a novel convolutional neural network architecture based on YOLO that learns the shape description of the objects.

    Our experiments on the KITTI dataset shows that the 3D YOLO has high accuracy and outperforms the state-of-the-art LiDAR-based models in efficiency. This makes it a suitable candidate for deployment in autonomous vehicles.

  • 3188. Al Hasib, Abdullah
    Design and implementation of Wireless Packet Level Authentication2009Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Secure user authentication, authorization and access control have become the major challenges in any wireless security system, often due to certain wireless network characteristics such as lack of infrastructure, low power availability and mobility. Taking advantage of such network characteristics, an attacker can launch several security attacks like Denial of Service (DoS) attacks, packet spoofing and session hijacking attacks. Packet Level Authentication (PLA) provides an elegant network level solution to the aforementioned attacks by allowing every node in the network to validate the authenticity and integrity of a packet without any prior contact with the originator of the packet.

    The cornerstone of PLA is public key cryptography based digital signature which is added do every outgoing packet by the packet originator. Therefore, signature generation and verification schemes of PLA become infeasible in resource-constrained devices if dedicated hardware accelerator is not used.

    In this thesis, we present Wireless Packet Level Authentication (WPLA) that extends PLA to offer an adaptive hop-by-hop signature verification scheme. WPLA includes a lightweight signature verification approach for resource-constrained devices while retaining the public key cryptography based signature verification scheme for strong authentication. Furthermore, to ensure end-to-end data confidentiality over the unsecured channels, we integrate a symmetric encryption scheme along with secret key generation and distribution process. Finally, we implement the proposed solution and evaluate the performance of our implementation.

  • 3189. Al Ismaeil, K.
    et al.
    Aouada, D.
    Mirbach, B.
    Ottersten, Björn
    Interdisciplinary Centre for Security, Reliability and Trust, Universtity of Luxembourg, Luxembourg.
    Depth super-resolution by enhanced shift and add2013In: Computer Analysis of Images and Patterns: 15th International Conference, CAIP 2013, York, UK, August 27-29, 2013, Proceedings, Part II, Springer, 2013, Vol. 8048 LNCS, no PART 2, p. 100-107Conference paper (Refereed)
    Abstract [en]

    We use multi-frame super-resolution, specifically, Shift & Add, to increase the resolution of depth data. In order to be able to deploy such a framework in practice, without requiring a very high number of observed low resolution frames, we improve the initial estimation of the high resolution frame. To that end, we propose a new data model that leads to a median estimation from densely upsampled low resolution frames. We show that this new formulation solves the problem of undefined pixels and further allows to improve the performance of pyramidal motion estimation in the context of super-resolution without additional computational cost. As a consequence, it increases the motion diversity within a small number of observed frames, making the enhancement of depth data more practical. Quantitative experiments run on the Middlebury dataset show that our method outperforms state-of-the-art techniques in terms of accuracy and robustness to the number of frames and to the noise level.

  • 3190. Al Ismaeil, K.
    et al.
    Aouada, D.
    Mirbach, B.
    Ottersten, Björn
    Advanced Engineering - IEE S.A., Luxembourg .
    Dynamic super resolution of depth sequences with non-rigid motions2013In: 2013 IEEE International Conference on Image Processing, ICIP 2013 - Proceedings, IEEE Signal Processing Society, 2013, p. 660-664Conference paper (Refereed)
    Abstract [en]

    We enhance the resolution of depth videos acquired with low resolution time-of-flight cameras. To that end, we propose a new dedicated dynamic super-resolution that is capable to accurately super-resolve a depth sequence containing one or multiple moving objects without strong constraints on their shape or motion, thus clearly outperforming any existing super-resolution techniques that perform poorly on depth data and are either restricted to global motions or not precise because of an implicit estimation of motion. The proposed approach is based on a new data model that leads to a robust registration of all depth frames after a dense upsampling. The textureless nature of depth images allows to robustly handle sequences with multiple moving objects as confirmed by our experiments.

  • 3191. Al Ismaeil, K.
    et al.
    Aouada, D.
    Mirbach, B.
    Ottersten, Björn
    SnT - Universtity of Luxembourg, Luxembourg .
    Multi-frame super-resolution by enhanced shift & add2013In: 2013 8th International Symposium on Image and Signal Processing and Analysis (ISPA), IEEE , 2013, p. 171-176Conference paper (Refereed)
    Abstract [en]

    A critical step in multi-frame super-resolution is the registration of frames based on their motion. We improve the performance of current state-of-the-art super-resolution techniques by proposing a more robust and accurate registration as early as in the initialization stage of the high resolution estimate. Indeed, we solve the limitations on scale and motion inherent to the classical Shift & Add approach by upsampling the low resolution frames up to the super-resolution factor prior to estimating motion or to median filtering. This is followed by an appropriate selective optimization, leading to an enhanced Shift & Add. Quantitative and qualitative evaluations have been conducted at two levels; the initial estimation and the final optimized superresolution. Results show that the proposed algorithm outperforms existing state-of-art methods.

  • 3192. Al Ismaeil, Kassem
    et al.
    Aouada, Djamila
    Mirbach, Bruno
    Ottersten, Björn
    KTH, School of Electrical Engineering (EES), Signal Processing. KTH, School of Electrical Engineering (EES), Centres, ACCESS Linnaeus Centre.
    Bilateral Filter Evaluation Based on Exponential Kernels2012Conference paper (Refereed)
    Abstract [en]

    The well-known bilateral filter is used to smooth noisy images while keeping their edges. This filter is commonly used with Gaussian kernel functions without real justification. The choice of the kernel functions has a major effect on the filter behavior. We propose to use exponential kernels with L1 distances instead of Gaussian ones. We derive Stein's Unbiased Risk Estimate to find the optimal parameters of the new filter and compare its performance with the conventional one. We show that this new choice of the kernels has a comparable smoothing effect but with sharper edges due to the faster, smoothly decaying kernels.

  • 3193.
    Al Jallad, Mohannad
    KTH, School of Information and Communication Technology (ICT).
    REA Business Modeling Language: Toward a REA based Domain Specific Visual Language2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Resources Events Agents (REA) ontology is a profound business modeling ontology that was developed to define the architecture of accounting information systems. Nevertheless, REA did not manage to get the same attention as other business modeling ontologies. One reason of such abandon is the absence of a meaningful visual notation for the ontology, which has resulted in an abstruse ontology to non-academic audience. Another reason for this abandon is the fact that REA does not have a standard formal representation. This has resulted in a humble amount of researches which have focused on defining meta-models of the ontology while neglecting the wider purpose of REA-based information systems development. Consequently, the ontology was deviated away from its original purpose, and rather used in business schools.

    To solve the aforementioned issues, this research presents a Model Driven Development (MDD) technique in the form of a REA-based Domain Specific Visual Language (DSVL) that is implemented within a modeling and code generation editor. This effort was taken in order to answer the question of “How would a REA-DSVL based tool make the REA ontology implementable in the domain of information systems development?”

    In order to answer the research question, a design science methodology (DSRM) was implemented as the structure of this research. The DSRM was chosen because this research aims to develop three main artifacts. These are; a meta-model of REA, a visual notation of REA, and a REA-DSVL-based modeling and code generation tool.

    The first phase of the DSRM was to identify the problems which were mentioned earlier, followed by the requirements identification phase which drew the outline of the; meta-model, the visual notation, and the tool. After that, the development phase was conducted in order to develop the aforementioned artifacts. The editor was then demonstrated using a case study of a local company in Stockholm-Sweden. Finally, the resulted artifacts were evaluated based on the collected requirements and the results from the case study.

    Based on the analyses of the artifacts and the case study, this research was concluded with the result that a REA-based DSVL tool can help in boosting the planning and analysis phases of the software development lifecycle (SDLC). This is achieved by automating some of the conventional software planning and design tasks, which would lead to more accurate systems’ designs; thus, minimizing the time of the planning and design phases. And it can be achieved by abstracting the direct logic of REA through providing functionalities that help users from different backgrounds (academic and professional) to embrace a business modeling editor rather than an ontology; thus, attracting a wider users base for implementing REA.

  • 3194.
    Al Karim, Miftah
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    PMU Data Mining in and analysis of suitable algorithm for fault pattern recognition.2012Independent thesis Advanced level (degree of Master (Two Years)), 20 credits / 30 HE creditsStudent thesis
    Abstract [en]

    Phasor measurement unit (PMU) is getting much attention in recent days to acquire power system data. It is because PMU provides the opportunity to collect high resolution system. Having a high resolution data provides scopes to monitor a system with different computational methods. Data mining is one of the effective methods. In the age of power system automation high resolution power system data storage and management has become more feasible. Data mining can be implemented on high resolution PMU data and many advantages can be achieved from such an operation.  

    Data mining is a scientific process through which a knowledge or patterns are identified from a large amount of data base. Data mining in power system based on PMU data is getting much focus in the recent years. Some of the prominent research on mining power system data and finding pattern is already going on in this field.

    There are different pattern recognition algorithms deployed in data mining field. Research has also been done to check the efficacy of those algorithms in action.

    In this thesis implementation of existing pattern recognition algorithms based on background study is carried out. Along with it one work-process is proposed to check out the possibilities of data mining in power system regarding fault pattern recognition. The mining process proposed here is a mixture of different existing algorithms and a new algorithm for fault classification. The work here mostly offers a broad perspective of data mining in power system rather than dealing with a specific application.

  • 3195.
    Al Karim, Miftah
    et al.
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Chenine, Moustafa
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Zhu, Kun
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Nordström, Lars
    KTH, School of Electrical Engineering (EES), Industrial Information and Control Systems.
    Synchrophasor-based data mining for power system fault analysis2012In: Innovative Smart Grid Technologies (ISGT Europe), 2012 3rd IEEE PES International Conference and Exhibition on, IEEE , 2012, p. 6465843-Conference paper (Refereed)
    Abstract [en]

    Phasor measurement units can provide high resolution and synchronized power system data, which can be effectively utilized for the implementation of data mining techniques. Data mining, based on pattern recognition algorithms can be of significant help for power system analysis, as high definition data is often complex to comprehend. In this paper three pattern recognition algorithms are applied to perform the data mining tasks. The deployment is carried out firstly for fault data classification, secondly for checking which faults are occurring more frequently and thirdly for identifying the root cause of a fault by clustering the parameters behind each scenario. For such purposes three algorithms are chosen, k-Nearest Neighbor, Naïve Bayes and the k-means Clustering.

  • 3196.
    Al Khatib, Iyad
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Performance Analysis of Application-Specific Multicore Systems on Chip2008Doctoral thesis, monograph (Other scientific)
    Abstract [en]

    The last two decades have witnessed the birth of revolutionary technologies in data communications including wireless technologies, System on Chip (SoC), Multi Processor SoC (MPSoC), Network on Chip (NoC), and more. At the same time we have witnessed that performance does not always keep pace with expectations in many services like multimediaservices and biomedical applications. Moreover, the IT market has suffered from some crashes. Hence, this triggered us to think of making use of available technologies and developing new ones so that the performance level is suitable for given applications and services. In the medical field, from a statistical viewpoint, the biggest diseases in number of deaths are heart diseases, namely Cardiovascular Disease (CVD) and Stroke. The application with the largest market for CVD is the electrocardiogram (ECG/EKG) analysis. According to the World Health Organization (WHO) report in 2003, 29.2% of global deaths are due to CVD and Stroke, half of which could be prevented if there was proper monitoring. We found in the new advance in microelectronics, NoC, SoC, and MPSoC, a chance of a solution for such a big problem. We look at the communication technologies, wireless networks, and MPSoC and realize that many projects can be founded, and they may affect people's lives positively, as for example, curing people more rapidly, as well as homecare of such large scale diseases. These projects have a medical impact as well as economic and social impacts. The intention is to use performance analysis of interconnected microelectronic systems and combine it with MPSoC and NoC technologies in order to evolve to new systems on chip that may make a difference. Technically, we aim at rendering more computations in less time, on a chip with smaller volume, and with less expense. The performance demand and the vision of having a market success, i.e. contributing to lower healthcare costs, pose many challenges on the hardware/software co-design to meet these goals. This calls upon the development of new integrated circuits featuring increased energy efficiency while providing higher computation capabilities, i.e. better performance. The biomedical application of ECG analysis is an ideal target for an application-specific SoC implementation. However, new 12-lead ECG analyses algorithms are needed to meet the aforementioned goals. In this thesis, we present two novel algorithms for ECG analysis, namely the Autocorrelation-Function (ACF) based algorithm and the Fast Fourier Transform (FFT) based algorithm. In this respect, we explore the design space by analyzing different hardware and software architectures. As a result, we realize a design with twelve processors that can compute 3.5 million arithmetic computations and respect the real time hard deadline for our biomedical application (3.5-4seconds), and that can deploy the ACF-based and FFT-based algorithms. Then, we investigate the configuration space looking for the most effective solution, performance and energy-wise. Consequently, we present three interconnect architectures (Single Bus, Full Crossbar, and Partial Crossbar) and compare them with existing solutions. The sampling frequencies of 2.2 KHz and 4 KHz, with 12 DSPs, are found to be the critical points for our Shared-Bus design and Crossbar architecture, respectively. We also show how our performance analysis methods can be applied to such a field of SoC design and with a specific purpose application in order to converge to a solution that is acceptable from a performance viewpoint, meets the real-time demands, and can be implemented with the present technologies while at the same time paving the way for easier and faster development. In order to connect our MPSoC solution to communication networks to transmit the medical results to a healthcare center, we come up with new protocols that will allow the integration of multiple networks on chips in a communication network. Finally, we present a methodology for HW/SW Codesign for application-specific systems (with focus on biomedical applications) that require a large number of computations since this will foster the convergence to solutions that are acceptable from a performance point of view.

  • 3197.
    Al Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Bertozzi, Davide
    Poletti, Francesco
    Benini, Luca
    Jantsch, Axel
    KTH, School of Information and Communication Technology (ICT), Electronic, Computer and Software Systems, ECS.
    Bechara, Mohamed
    Khalifeh, Hasan
    Hajjar, Mazen
    Nabiev, Rustam
    Jonsson, Sven
    Hardware/Software architecture for real-time ECG monitoring and analysis leveraging MPSoC technology2007In: Transactions on High-Performance Embedded Architectures and Compilers I / [ed] tenstrom, P; OBoyle, M; Bodin, F; Cintra, M; McKee, SA, 2007, Vol. 4050, p. 239-258Conference paper (Refereed)
    Abstract [en]

    The interest in high performance chip architectures for biomedical applications is gaining a lot of research and market interest. Heart diseases remain by far the main cause of death and a challenging problem for biomedical engineers to monitor and analyze. Electrocardiography (ECG) is an essential practice in heart medicine. However, ECG analysis still faces computational challenges, especially when 12 lead signals are to be analyzed in parallel, in real time, and under increasing sampling frequencies. Another challenge is the analysis of huge amounts of data that may grow to days of recordings. Nowadays, doctors use eyeball monitoring of the 12-lead ECG paper readout, which may seriously impair analysis accuracy. Our solution leverages the advance in multi-processor system-on-chip architectures, and it is centered on the parallelization of the ECG computation kernel. Our Hardware- Software (HW/SW) Multi-Processor System-on-Chip (MPSoQ design improves upon state-of-the-art mostly for its capability to perform real-time analysis of input data, leveraging the computation horsepower provided by many concurrent DSPs, more accurate diagnosis of cardiac diseases, and prompter reaction to abnormal heart alterations. The design methodology to go from the 12-lead ECG application specification to the final HW/SW architecture is the focus of this paper. We explore the design space by considering a number of hardware and software architectural variants, and deploy industrial components to build up the system.

  • 3198.
    Al Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT. iITC, Sweden .
    Ismail, M.
    WNoC: A microelectronic system architecture suitable for biomedical wireless sensor networks2005Conference paper (Refereed)
    Abstract [en]

    This paper presents a low-cost microelectronic system architecture suitable for single chip CMOS integration. The system architecture consists of a large set of on-chip processing-cores, sensors, and four multi-standard wireless border cores that are interconnected to form an ultra-fast microelectronic network of distributed-computing systems. Our main application areas are: biomedical emergency monitoring systems and healthcare. The hardware platform is based on Network-on-Chip (NoC) design and RF circuitry for wireless connectivity. We focus on the design of this Wireless Network-on-Chip (WNoC). WNoC faces several challenges. A main issue of concern from the application point of view is to have the design support the convergence to a decision within acceptable periods of time, because time is critical in many medical healthcare applications. We define a mechanism to enable many WNoCs to interact together over the wireless media. A key result is a design and protocol for internal and external WNoC communications between the main and backup wireless cores. We run simulations on a biomedical monitoring system for emergency situations, and our results show that the time to converge to a medical warning is in the range of milliseconds, which is acceptable for the related medical scenarios.

  • 3199.
    Al Khatib, Iyad
    et al.
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Jantsch, Axel
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    Nabiev, Rustam
    KTH, School of Information and Communication Technology (ICT), Microelectronics and Information Technology, IMIT.
    ECG-BIONET: A global biomedical network for human heart monitoring and analysis: Performance needs of an electrocardiogram Telemedicine platform for medical aid at the point-of-need2006In: 25TH IEEE INTERNATIONAL CONFERENCE ON COMPUTER COMMUNICATIONS: VOLS 1-7, PROCEEDINGS IEEE INFOCOM 2006, New York: IEEE , 2006, p. 3282-3283Conference paper (Refereed)
    Abstract [en]

    In this paper, we propose a Tele-medicine application platform as a medical aid for patients suffering from Heart malfunction. We focus on heart diseases since they remain by far the major cause of death in the globe. Our solution utilizes the Satellite communication protocol DVB-RCS (Digital Video Broadcast- Return Channel Satellite), Wi-Fi, and the Network-on-Chip (NoC) technology. We utilize the 12-lead ECG biomedical technique to detect heart disorders via the biomedical NoC, which transmits the medical alarm and results via the biomedical network, ECG-BIONET. We do not investigate the DVB-RCS standard or Wi-Fi technology, but rather we try to utilize this technology, and we look at it from a performance point of view for our application by investigating three parameters, namely: delay, packet loss, and reliability. We follow a top down approach by looking at the needs of the application from a performance guarantee for our specific-purpose network.

  • 3200.
    Al Khatib, Lyad
    KTH, Superseded Departments, Microelectronics and Information Technology, IMIT.
    Performance anaalysis of wireless LAN access points2003Licentiate thesis, comprehensive summary (Other scientific)
61626364656667 3151 - 3200 of 125184
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