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Browsing by Subject "Tölvunarfræði"

Browsing by Subject "Tölvunarfræði"

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  • Koziel, Slawomir; Bekasiewicz, Adrian (Institute of Electrical and Electronics Engineers (IEEE), 2020-04-13)
    The paper proposes a novel framework for accelerated re-design (dimension scaling) of antenna structures using inverse surrogates. The major contribution of the work is a sensitivity-based model identification procedure, which permits a significant ...
  • Koistinen, Olli-Pekka (Aalto University School of Science, 2019)
    Chemical reactions and other transitions involving rearrangements of atoms can be studied theoretically by analyzing a potential energy surface defined in a high-dimensional space of atom coordinates. Local minimum points of the energy surface correspond ...
  • Ullah, Ubaid; Al-Hasan, Muath; Koziel, Slawomir; Mabrouk, Ismail Ben (Institute of Electrical and Electronics Engineers (IEEE), 2020)
    In this paper, a multiple-input-multiple-output (MIMO) antenna featuring circular polarization diversity, and designed on a common coplanar ground is presented. The proposed antenna design utilizes a coplanar waveguide (CPW) feeding technique with three ...
  • Pietrenko-Dabrowska, Anna; Koziel, Slawomir; Al-Hasan, Mu'ath (Institute of Electrical and Electronics Engineers (IEEE), 2020)
    Over the recent years, surrogate modeling has been playing an increasing role in the design of antenna structures. The main incentive is to mitigate the issues related to high cost of electromagnetic (EM)-based procedures. Among the various techniques, ...
  • Koziel, Slawomir; Pietrenko-Dabrowska, Anna; Al-Hasan, Mu'ath (Institute of Electrical and Electronics Engineers (IEEE), 2020)
    Contemporary microwave design heavily relies on full-wave electromagnetic (EM) simulation tools. This is especially the case for miniaturized devices where EM cross-coupling effects cannot be adequately accounted for using equivalent network models. ...
  • Hyytia, Esa; Righter, Rhonda; Bilenne, Olivier; Wu, Xiaohu (Elsevier BV, 2017-09)
    We study the M/D/1 queue when jobs have firm deadlines for waiting (or sojourn) time. If a deadline is not met, a job-specific deadline violation cost is incurred. We derive explicit value functions for this M/D/1 queue that enable the development of ...
  • Ullah, Ubaid; Mabrouk, Ismail Ben; Koziel, Slawomir (Institute of Electrical and Electronics Engineers (IEEE), 2020)
    Design of a compact wideband circularly polarized (CP) multiple-input multiple-output (MIMO) antenna with polarization diversity is proposed and characterized for off-body communication. The antenna is based on a simple coplanar waveguide (CPW)-fed ...
  • Bean, Christian; Claesson, Anders; Úlfarsson, Henning Arnór (University of Waterloo, 2017)
    Vincular and covincular patterns are generalizations of classical patterns allowing restrictions on the indices and values of the occurrences in a permutation. In this paper we study the integer sequences arising as the enumerations of permutations ...
  • Tomasson, Jon Atli; Koziel, Slawomir; Pietrenko-Dabrowska, Anna (Institute of Electrical and Electronics Engineers (IEEE), 2020)
    Optimization-based parameter tuning has become an inherent part of contemporary antenna design process. For the sake of reliability, it is typically conducted at the level of full-wave electromagnetic (EM) simulation models. This may incur considerable ...
  • Book, Matthias; Riedel, Morris; Neukirchen, Helmut; Götz, Markus (ACM Press, 2017-10)
    The design, development and deployment of scientific computing applications can be quite complex as they require scientific, High-Performance Computing (HPC), and software engineering expertise. Often, HPC applications are however developed by end users ...
  • Bean, Christian (2018-06)
    New automatic methods for enumerating permutation classes are introduced. The first is Struct, which is an algorithm that conjectures a structural description using rules similar to generalized grid classes. These conjectured structural descriptions ...
  • Eggertsson, Hannes; Kristmundsdóttir, Snædís; Beyter, Doruk; Jónsson, Hákon; Skúladóttir, Ástrós; Hardarson, Marteinn; Gudbjartsson, Daniel; Stefansson, Kari; Halldórsson, Bjarni; Melsted, Páll (Springer Science and Business Media LLC, 2019-11-27)
    Analysis of sequence diversity in the human genome is fundamental for genetic studies. Structural variants (SVs) are frequently omitted in sequence analysis studies, although each has a relatively large impact on the genome. Here, we present GraphTyper2, ...
  • Eggertsson, Hannes (University of Iceland, School of Engineering and Natural Sciences, Faculty of Industrial Engineering, Mechanical Engineering and Computer Science, 2019-06)
    A fundamental requisite for genetic studies is an accurate determination of sequence variation. While human genome sequence diversity is increasingly well characterized, there is a need for efficient ways to utilize this knowledge in sequence analysis. ...
  • Halldórsson, Magnús M.; Konrad, Christian (Elsevier BV, 2020-04)
    We give a distributed (1+eps)-approximation algorithm for the minimum vertex coloring problem on interval graphs, which runs in the LOCAL model and operates in O((1/eps) log* n) rounds. If nodes are aware of their interval representations, then the ...
  • Halldórsson, Magnús M.; Holzer, Stephan; Markatou, Evangelia Anna; Lynch, Nancy (Elsevier BV, 2020-04)
    We consider the Leader Election Problem in the Signal-to-Interference-plusNoise-Ratio (SINR) model where nodes can adjust their transmission power. We show that in this setting it is possible to elect a leader in two communication rounds, with high ...
  • Argáez, Carlos; Berthet, Jean-Claude; Björnsson, Hjörtur; Giesl, Peter; Hafstein, Sigurdur (Elsevier BV, 2019-07)
    LyapXool is a C++ program to compute complete Lyapunov functions and their orbital derivatives for any two- or three-dimensional dynamical system expressed by an autonomous ordinary differential equation. The program is user-friendly and determines the ...
  • Khamespanah, Ehsan (2018-06)
    In the recent years, formal modeling and verification of realtime systems have become very important. Difficult-to-use modeling languages and inefficient analysis tools are the main obstacles to use formal methods in this domain. Timed actor model is ...
  • Lejsek, Herwig (2016-02)
    This thesis presents the NV-tree (Nearest Vector tree), which addresses thespecific problem of efficiently and effectively finding the approximatek-nearest neighbors within large collections of high-dimensional data points.The NV-tree is a very ...
  • Ali, Jafari (2016-06)
    This dissertation is composed of two parts. In the first part, performance evaluation and verification of safety properties are provided for real-time actors. Recently, the actor-based language, Timed Rebeca, was introduced to model distributed and ...
  • Aceto, Luca; Fabregas, Ignacio; Garcia-Perez, Alvaro; Ingolfsdottir, Anna; Ortega-Mallen, Yolanda (2019-10-14)
    The nominal transition systems (NTSs) of Parrow et al. describe the operational semantics of nominal process calculi. We study NTSs in terms of the nominal residual transition systems (NRTSs) that we introduce. We provide rule formats for the specifications ...