Endre søk
Begrens søket
3456789 251 - 300 of 3506
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf
Treff pr side
  • 5
  • 10
  • 20
  • 50
  • 100
  • 250
Sortering
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
  • Standard (Relevans)
  • Forfatter A-Ø
  • Forfatter Ø-A
  • Tittel A-Ø
  • Tittel Ø-A
  • Type publikasjon A-Ø
  • Type publikasjon Ø-A
  • Eldste først
  • Nyeste først
  • Skapad (Eldste først)
  • Skapad (Nyeste først)
  • Senast uppdaterad (Eldste først)
  • Senast uppdaterad (Nyeste først)
Merk
Maxantalet träffar du kan exportera från sökgränssnittet är 250. Vid större uttag använd dig av utsökningar.
  • 251. Babuska, I.
    et al.
    Nobile, F.
    Tempone, Raul
    KTH, Skolan för datavetenskap och kommunikation (CSC), Numerisk analys, NA.
    Formulation of the static frame problem2008Inngår i: Computer Methods in Applied Mechanics and Engineering, ISSN 0045-7825, E-ISSN 1879-2138, Vol. 197, nr 29-32, 2496-2499 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    This report describes a static framework validation challenge problem used in the SANDIA Validation Challenge Workshop, May 21-23, 2006. The challenge problem has clear engineering character, is simple to state and allows many different approaches to solve it. The regulatory assessment problem is to estimate the probability of a given vertical displacement to exceed a prescribed threshold.

  • 252. Babuska, I.
    et al.
    Tempone Olariaga, Raul
    KTH, Tidigare Institutioner                               , Numerisk analys och datalogi, NADA.
    Zouraris, Georgios
    Galerkin finite element approximations of stochastic elliptic partial differential equations2004Inngår i: SIAM Journal on Numerical Analysis, ISSN 0036-1429, E-ISSN 1095-7170, Vol. 42, nr 2, 800-825 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We describe and analyze two numerical methods for a linear elliptic problem with stochastic coefficients and homogeneous Dirichlet boundary conditions. Here the aim of the computations is to approximate statistical moments of the solution, and, in particular, we give a priori error estimates for the computation of the expected value of the solution. The first method generates independent identically distributed approximations of the solution by sampling the coefficients of the equation and using a standard Galerkin finite element variational formulation. The Monte Carlo method then uses these approximations to compute corresponding sample averages. The second method is based on a finite dimensional approximation of the stochastic coefficients, turning the original stochastic problem into a deterministic parametric elliptic problem. A Galerkin finite element method, of either the h- or p-version, then approximates the corresponding deterministic solution, yielding approximations of the desired statistics. We present a priori error estimates and include a comparison of the computational work required by each numerical approximation to achieve a given accuracy. This comparison suggests intuitive conditions for an optimal selection of the numerical approximation.

  • 253. Backman, Anders
    et al.
    Bodin, Kenneth
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Högpresterande beräkningscentrum norr (HPC2N).
    Lacoursière, Claude
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Högpresterande beräkningscentrum norr (HPC2N).
    Servin, Martin
    Umeå universitet, Teknisk-naturvetenskapliga fakulteten, Institutionen för fysik.
    Democratizing CAE with Interactive Multiphysics Simulation and Simulators2012Konferansepaper (Annet vitenskapelig)
  • 254.
    Baek, Seung Ki
    et al.
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Fysik.
    Bernhardsson, Sebastian
    Umeå universitet, Teknisk-naturvetenskaplig fakultet, Fysik.
    Equilibrium solution to the lowest unique positive integer game2010Inngår i: Fluctuation and Noise Letters, ISSN 0219-4775, E-ISSN 1793-6780, Vol. 9, nr 1, 61-68 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We address the equilibrium concept of a reverse auction game so that no one can enhance the individual payoff by a unilateral change when all the others follow a certain strategy. In this approach the combinatorial possibilities to consider become very much involved even for a small number of players, which has hindered a precise analysis in previous works. We here present a systematic way to reach the solution for a general number of players, and show that this game is an example of conflict between the group and the individual interests.

  • 255.
    Bagge, Joar
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Numerisk analys, NA.
    Numerical simulation of an inertial spheroidal particle in Stokes flow2015Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Particle suspensions occur in many situations in nature and industry. In this master’s thesis, the motion of a single rigid spheroidal particle immersed in Stokes flow is studied numerically using a boundary integral method and a new specialized quadrature method known as quadrature by expansion (QBX). This method allows the spheroid to be massless or inertial, and placed in any kind of underlying Stokesian flow.

     

    A parameter study of the QBX method is presented, together with validation cases for spheroids in linear shear flow and quadratic flow. The QBX method is able to compute the force and torque on the spheroid as well as the resulting rigid body motion with small errors in a short time, typically less than one second per time step on a regular desktop computer. Novel results are presented for the motion of an inertial spheroid in quadratic flow, where in contrast to linear shear flow the shear rate is not constant. It is found that particle inertia induces a translational drift towards regions in the fluid with higher shear rate.

  • 256.
    Baloglu, Maximilian Volkan
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Numerisk analys, NA.
    Parallelisation and Performance Analysis of a TreeSPH Code for Galaxy Simulations2014Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    In cosmological simulations, the Lagrangian method Smoothed Particle Hydrodynamics is often applied to cover gas dynamics and combined with tree algorithms for long-range potentials like the Barnes-Hut method to include self-gravity and derive the nearest neighbour lists efficiently. In this thesis, a so-called TreeSPH code is parallelized by using MPI and subsequently the performance is analysed. For the domain decomposition to the processes, the structure of an octree is examined and space filling curves are applied to achieve well-working dynamical load balancing. For an efficient parallel SPH calculation, a novel method with a localised boundary handling is proposed to reduce communication overhead

  • 257.
    Bangert, U.
    et al.
    School of Physics, University of Exeter.
    Barnes, R.
    Lunar & Planetary Lab., Arizona University, Tucson.
    Hounsome, L.S.
    School of Physics, University of Exeter.
    Jones, R.
    School of Physics, University of Exeter.
    Blumenau, A.T.
    Max-Planck-Institut für Eisenforschung GmbH.
    Briddon, P.R.
    School of Natural Science, University of Newcastle upon Tyne.
    Shaw, M.J.
    School of Natural Science, University of Newcastle upon Tyne.
    Öberg, Sven
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, Matematiska vetenskaper.
    Electron energy loss spectroscopic studies of brown diamonds2006Inngår i: Philosophical Magazine, ISSN 1478-6435, E-ISSN 1478-6443, Vol. 86, nr 29-31, 4757-4779 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We investigate both experimentally and theoretically, low-loss electron energy losses in brown type IIa monocrystalline diamonds both before and after high-temperature, high-pressure anneals which remove the brown colouration. We find additional losses within and near the band edge for brown diamond which are significantly reduced after treatment. The additional losses are not associated with dislocations. Graphitic inclusions are detected by EELS as well as TEM studies for some brown diamonds before treatment. These lead to pronounced subgap absorption. However, all brown diamonds exhibit additional losses which are due to point defects lying in the regions between dislocations. First principles theoretical modelling shows that common dislocations are not responsible for the brown colouration but a -bonded vacancy disk lying on {111} planes gives broad bands lying in the diamond band gap, possesses an optical absorption spectrum similar to that of brown diamond, and leads to additional electron energy losses in the band edge region. These and similar defects are suggested to be responsible for the brown colouration. Mechanisms are proposed for their formation and removal.

  • 258. Bangerth, Wolfgang
    et al.
    Burstedde, Carsten
    Heister, Timo
    Kronbichler, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Algorithms and data structures for massively parallel generic adaptive finite element codes2011Inngår i: ACM Transactions on Mathematical Software, ISSN 0098-3500, Vol. 38, nr 2, 14:1-28 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 259. Bani-Hashemian, Hossein
    et al.
    Hellander, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Lötstedt, Per
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Efficient sampling in event-driven algorithms for reaction-diffusion processes2011Rapport (Annet vitenskapelig)
  • 260. Bani-Hashemian, Mohammad Hossein
    et al.
    Hellander, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Lötstedt, Per
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Efficient sampling in event-driven algorithms for reaction-diffusion processes2013Inngår i: Communications in Computational Physics, ISSN 1815-2406, Vol. 13, 958-984 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 261.
    Bao, Lei
    et al.
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Skoglund, Mikael
    KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre. KTH, Skolan för elektro- och systemteknik (EES), Kommunikationsteori.
    Fischione, Carlo
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Johansson, Karl Henrik
    KTH, Skolan för elektro- och systemteknik (EES), Reglerteknik. KTH, Skolan för elektro- och systemteknik (EES), Centra, ACCESS Linnaeus Centre.
    Rate allocation for quantized control over noisy channels2009Inngår i: Final Proceedings of the 2009 7th International Symposium on Modeling and Optimization in Mobile, Ad Hoc and Wireless Networks, 2009, Vol. WiOpt 2009, 595-603 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    To achieve satisfactory overall performance, optimal rate allocation in a networked control system with highly limited communication resources is instrumental. In this paper, a rate allocation technique for state feedback control in linear dynamic systems over a noisy channel is proposed. The method consists of two steps: (i) the overall cost is expressed as a function of rates at all time instants by means of high-rate quantization theory, and (ii) a constrained optimization problem to minimize the overall distortion is solved. It is shown that a non-uniform quantization is in general the best strategy for state feedback control over noisy channels. Monte Carlo simulations illustrate the proposed scheme, which is shown to have good performance when compared to arbitrarily selected rate allocations.

  • 262.
    Barbouche, Tarek
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematisk statistik.
    Extreme Value Theory Applied to Securitizations Rating Methodology2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    One of today’s financial trends is securitization. Evaluating Securitization risk requires some strong quantitative skills and a deep understanding of both credit and market risk. For international securitization programs it is mandatory to take into account the exchange-rates-related risks. We will see the di˙erent methods to evaluate extreme variations of the exchange rates using the Extreme Value Theory and Monte Carlo simulations.

  • 263.
    Barestrand, Henrik
    et al.
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Forslund, Tobias
    Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik.
    Numerical & physical modelling of fluid flow in a continuous casting mould: Flow dynamics studies for flexible operation of continuous casters2016Independent thesis Advanced level (professional degree), 20 poäng / 30 hpOppgave
    Abstract [en]

    The current demands on Swedish steel industry to produce low quantity batches of specialized products requires research on steel casting processes. There are several physical processes that need be taken into account for this problem to be viewed in full light such as thermal-processes, solidification and fluid dynamics. This work focuses on the fluid-dynamics part; more specifically, the dependence of flow quality within the caster on nozzle and mould geometry.

    The simulations are carried out using a scale-resolving method, in specific LES (Large Eddy Simulation) which is coupled with a DPM (Discrete Phase Model) to model Argon behaviour. The results of these simulations are presented and validated against physical experiment and data from industrial trials. Conclusions are drawn regarding optimal nozzle types in respect to different mould geometries.

    The mould eigenfrequencies are shown to exhibit a connection with the casting velocity. This results in so called sweet spots in casting velocity where flow irregularities due to sloshing is minimal. It is shown that the mountain type nozzle is preferable for smaller geometries whilst comparatively larger geometries benefit from a cup type.

  • 264. Bar-Gera, Hillel
    et al.
    Hellman, Fredrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Patriksson, Michael
    Computational precision of traffic equilibria sensitivities in automatic network design and road pricing2013Inngår i: Procedia - Social and Behavioral Sciences, ISSN 1877-0428, Vol. 80, 41-60 s.Artikkel i tidsskrift (Annet vitenskapelig)
  • 265. Bar-Gera, Hillel
    et al.
    Hellman, Fredrik
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Patriksson, Michael
    Computational precision of traffic equilibria sensitivities in automatic network design and road pricing2013Inngår i: Transportation Research Part B: Methodological, ISSN 0191-2615, Vol. 57, 485-500 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 266. Barrera, Tony
    et al.
    Olsson, Pelle
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    An integer based square root algorithm1993Inngår i: BIT Numerical Mathematics, ISSN 0006-3835, E-ISSN 1572-9125, Vol. 33, 254-261 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 267. Barrera, Tony
    et al.
    Spångberg, Daniel
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Kemiska sektionen, Institutionen för materialkemi, Strukturkemi.
    Hast, Anders
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Centrum för bildanalys.
    Bengtsson, Ewert
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Centrum för bildanalys.
    Vectorized table driven algorithms for double precision elementary functions using taylor expansions2009Inngår i: Aplimat: journal of applied mathematics, ISSN 1337-6365, Vol. 2, nr 3, 171-187 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 268.
    Bartlett, Roscoe A.
    et al.
    Sandia National Laboratories.
    Van Bloemen Waanders, Bart
    Sandia National Laboratories.
    Berggren, Martin
    Department of Information Technology, Uppsala University.
    Hybrid Differentiation Strategies for Simulation and Analysis of Applications in C++2008Inngår i: ACM Transactions on Mathematical Software, ISSN 0098-3500, E-ISSN 1557-7295, Vol. 35, nr 1Artikkel i tidsskrift (Fagfellevurdert)
  • 269. Bartlett, Roscoe A.
    et al.
    van Bloemen Waanders, Bart G.
    Berggren, Martin
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Hybrid differentiation strategies for simulation and analysis of applications in C++2008Inngår i: ACM Transactions on Mathematical Software, ISSN 0098-3500, Vol. 35, nr 1, 1:1-29 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 270.
    Bartold, Martina
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Matematisk statistik.
    Modelling of Private Infrastructure Debt in a Risk  Factor Model2017Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [en]

    Allocation to private infrastructure debt investments has increased in the recent years [15]. For managers of multi-asset portfolios, it is important to be able to assess the risk of the total portfolio and the contribution to risk of the various holdings in the portfolio. This includes being able to explain the risk of having private infrastructure debt investments in the portfolio.

    The modelling of private infrastructure debt face many challenges, such as the lack of private data and public indices for private infrastructure debt. In this thesis, two approaches for modelling private infrastructure debt in a parametric risk factor model are proposed. Both approaches aim to incorporate revenue risk, which is the risk occurring from the type of revenue model in the infrastructure project or company.

    Revenue risk is categorised into three revenue models; merchant, contracted and regulated, as spread level differences can be distinguished for private infrastructure debt investments using this categorisation. The difference in spread levels between the categories are used to estimate β coefficients for the two modelling approaches. The spread levels are obtained from a data set and from a previous study.

    In the first modelling approach, the systematic risk factor approach, three systematic risk factors are introduced where each factor represent infrastructure debt investments with a certain revenue model. The risk or the volatility for each of these factors is the volatility of a general infrastructure debt index adjusted with one of the β coefficients.

    In the second modelling approach, the idiosyncratic risk term approach, three constant risk terms for the revenue models are added in order to capture the revenue risk for private infrastructure debt investments. These constant risk terms are estimated with the β coefficients and the historical volatility of a infrastructure debt index.

    For each modelling approach, the commonly used risk measures standalone risk and risk contribution are presented for the entire block of the infrastructure debt specific factors and for each of the individual factors within this block.

    Both modelling approaches should enable for better explanation of risk in private infrastructure debt investments by introducing revenue risk. However, the modelling approaches have not been backtested and therefore no conclusion can be made in regards to whether one of the proposed modelling approaches actually is better than current modelling approaches for private infrastructure debt.

  • 271.
    Bartolini, Gabriel
    Linköpings universitet, Matematiska institutionen, Tillämpad matematik. Linköpings universitet, Tekniska högskolan.
    On the Branch Loci of Moduli Spaces of Riemann Surfaces of Low Genera2009Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Compact Riemann surfaces of genus greater than 1 can be realized as quotient spaces of the hyperbolic plane by the action of Fuchsian groups. The Teichmüller space is the set of all complex structures of Riemann surfaces and the moduli space the set of conformal equivalence classes of Riemann surfaces. For genus greater than two the branch locus of the covering of the moduli space by the Teichmüller space can be identified wi the set of Riemann surfaces admitting non-trivial automorphisms. Here we give the orbifold structure of the branch locus of surfaces of genus 5 by studying the equisymmetric stratification of the branch locus. This gives the orbifold structure of the moduli space.

    We also show that the strata corresponding to surfaces with automorphisms of order 2 and 3 belong to the same connected component for every genus. Further we show that the branch locus is connected with the exception of one isolated point for genera 5 and 6, it is connected for genus 7 and it is connected with the exception of two isolated points for genus 8.

  • 272.
    Bartolini, Gabriel
    et al.
    Linköpings universitet, Matematiska institutionen, Tillämpad matematik. Linköpings universitet, Tekniska högskolan.
    Izquierdo, Milagros
    Linköpings universitet, Matematiska institutionen, Tillämpad matematik. Linköpings universitet, Tekniska högskolan.
    ON THE CONNECTEDNESS OF THE BRANCH LOCUS OF THE MODULI SPACE OF RIEMANN SURFACES OF GENUS 42010Inngår i: Glasgow Mathematical Journal, ISSN 0017-0895, E-ISSN 1469-509X, Vol. 52, 401-408 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Let g be an integer ≥ 3 and let θg = {X ∈ Mg|Aut(X) ≠ 1d}, where Mg denotes the moduli space of a compact Riemann surface. Using uniformization of Riemann surfaces by Fuchsian groups and the equisymmetric stratification of the branch locus of the moduli space we prove that the subloci corresponding to Riemann surfaces with automorphism groups isomorphic to cyclic groups of order 2 and 3 belongs to the same connected component. We also prove the connectedness of θg for g = 5, 6, 7 and 8 with the exception of the isolated points given by Kulkarni.

  • 273.
    Basieva, Irina
    et al.
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för matematik (MA).
    Khrennikov, Andrei
    Linnéuniversitetet, Fakulteten för teknik (FTK), Institutionen för matematik (MA).
    Decision-making and cognition modeling from the theory of mental instruments2017Inngår i: The Palgrave Handbook of Quantum Models in Social Science: Applications and Grand Challenges / [ed] Emmanuel Haven, Andrei Khrennikov, Palgrave Macmillan, 2017, 75-93 s.Kapittel i bok, del av antologi (Annet vitenskapelig)
    Abstract [en]

    The authors present the theory of quantum measurements in a humanities friendly way. The most general process of decision-making is represented with the aid of the formalism of quantum apparatuses and instruments. This measurement formalism generalizes the standard one based on the von Neumann–Lüders projection postulate. Generalized quantum observables are mathematically represented as positive operator valued measures (POVMs) and state transformers resulting from the feedback of measurements to the states of systems that are given by quantum instruments. The quantum scheme of indirect measurements (a special realization of quantum instruments) is applied to model decision-making as resulting from the interaction between the belief and decision states. The authors analyze the specific features of quantum instruments which are important for cognitive and social applications. In particular, the state transformers given by quantum instruments are in general less invasive than the state projections. Thus quantum-like decision-making need not be viewed as a kind of state collapse.

  • 274.
    Bastian, Peter
    et al.
    University of Heidelberg.
    Berninger, Heiko
    Dedner, Andreas
    University of Warwick.
    Engwer, Christian
    University of Münster.
    Henning, Patrick
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Numerisk analys, NA.
    Kornhuber, Ralf
    FU Berlin.
    Kröner, Dietmar
    University of Freiburg.
    Ohlberger, Mario
    University of Münster.
    Sander, Oliver
    TU Dresden.
    Schiffler, Gerd
    Shokina, Nina
    Smetana, Kathrin
    University of Münster.
    Adaptive Modelling of Coupled Hydrological Processes with Application in Water Management2012Inngår i: Progress in Industrial Mathematics at ECMI 2010 / [ed] Michael Günther and Andreas Bartel and Markus Brunk and Sebastian Schöps and Michael Striebel, Springer Berlin/Heidelberg, 2012, 561-567 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    This paper presents recent results of a network project aiming at the modelling and simulation of coupled surface and subsurface flows. In particular, a discontinuous Galerkin method for the shallow water equations has been developed which includes a special treatment of wetting and drying. A robust solver for saturated–unsaturated groundwater flow in homogeneous soil is at hand, which, by domain decomposition techniques, can be reused as a subdomain solver for flow in heterogeneous soil. Coupling of surface and subsurface processes is implemented based on a heterogeneous nonlinear Dirichlet–Neumann method, using the dune-grid-glue module in the numerics software DUNE.

  • 275.
    Bauer, Pavol
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Parallelism and efficiency in discrete-event simulation2015Licentiatavhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    Discrete-event models depict systems where a discrete state is repeatedly altered by instantaneous changes in time, the events of the model. Such models have gained popularity in fields such as Computational Systems Biology or Computational Epidemiology due to the high modeling flexibility and the possibility to easily combine stochastic and deterministic dynamics. However, the system size of modern discrete-event models is growing and/or they need to be simulated at long time periods. Thus, efficient simulation algorithms are required, as well as the possibility to harness the compute potential of modern multicore computers. Due to the sequential design of simulators, parallelization of discrete event simulations is not trivial. This thesis discusses event-based modeling and sensitivity analysis and also examines ways to increase the efficiency of discrete-event simulations and to scale models involving deterministic and stochastic spatial dynamics on a large number of processor cores.

  • 276.
    Bauer, Pavol
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Engblom, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Sensitivity estimation and inverse problems in spatial stochastic models of chemical kinetics2015Inngår i: Numerical Mathematics and Advanced Applications: ENUMATH 2013, Springer, 2015, 519-527 s.Konferansepaper (Fagfellevurdert)
  • 277. Bauer, Pavol
    et al.
    Engblom, Stefan
    Mikulovic, Sanja
    Senek, Aleksandar
    Multiscale modeling via split-step methods in neural firingInngår i: Mathematical and Computer Modelling of Dynamical Systems, ISSN 1387-3954, E-ISSN 1744-5051Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Neuronal models based on the Hodgkin-Huxley equation form a  fundamental framework in the field of computational  neuroscience. While the neuronal state is often modeled  deterministically, experimental recordings show stochastic  fluctuations, presumably driven by molecular noise from the  underlying microphysical conditions. In turn, the firing of  individual neurons gives rise to an electric field in extracellular  space, also thought to affect the firing pattern of nearby neurons.  We develop a multiscale model which combines a stochastic ion  channel gating process taking place on the neuronal membrane,  together with the propagation of an action potential along the  neuronal structure. We also devise a numerical method relying on a  split-step strategy which effectively couples these two processes  and we experimentally test the feasibility of this approach. We  finally also explain how the approach can be extended with Maxwell's  equations to allow the potential to be propagated in extracellular  space.

  • 278.
    Bauer, Pavol
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Engblom, Stefan
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för beräkningsvetenskap. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Tillämpad beräkningsvetenskap.
    Widgren, Stefan
    Fast event-based epidemiological simulations on national scales2016Inngår i: The international journal of high performance computing applications, ISSN 1094-3420, E-ISSN 1741-2846, Vol. 30, 438-453 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 279. Bayer, Christian
    et al.
    Hoel, Håkon
    KTH, Skolan för teknikvetenskap (SCI), Matematik (Inst.), Numerisk analys, NA.
    von Schwerin, Erik
    Tempone, Raul
    On nonasymptotic optimal stopping criteria in monte carlo simulations2014Inngår i: SIAM Journal on Scientific Computing, ISSN 1064-8275, E-ISSN 1095-7197, Vol. 36, nr 2, A869-A885 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    We consider the setting of estimating the mean of a random variable by a sequential stopping rule Monte Carlo (MC) method. The performance of a typical second moment based sequential stopping rule MC method is shown to be unreliable in such settings both by numerical examples and through analysis. By analysis and approximations, we construct a higher moment based stopping rule which is shown in numerical examples to perform more reliably and only slightly less efficiently than the second moment based stopping rule.

  • 280.
    Bazarganzadeh, Mahmoudreza
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Matematiska institutionen, Analys och tillämpad matematik.
    Free Boundary Problems of Obstacle Type, a Numerical and Theoretical Study2012Doktoravhandling, med artikler (Annet vitenskapelig)
    Abstract [en]

    This thesis consists of five papers and it mainly addresses the theory and schemes to approximate the quadrature domains, QDs. The first deals with the uniqueness and some qualitative properties of the two QDs. The concept of two phase QDs, is more complicated than its one counterpart and consequently introduces significant and interesting open.

    We present two numerical schemes to approach the one phase QDs in the paper. The first method is based on the properties of the free boundary the level set techniques. We use shape optimization analysis to construct second method. We illustrate the efficiency of the schemes on a variety of experiments.

    In the third paper we design two finite difference methods for the approximation of the multi phase QDs. We prove that the second method enjoys monotonicity, consistency and stability and consequently it is a convergent scheme by Barles-Souganidis theorem. We also present various numerical simulations in the case of Dirac measures.

    We introduce the QDs in a sub domain of and Rn study the existence and uniqueness along with a numerical scheme based on the level set method in the fourth paper.

    In the last paper we study the tangential touch for a semi-linear problem. We prove that there is just one phase free boundary points on the flat part of the fixed boundary and it is also shown that the free boundary is a uniform C1-graph up to that part.

  • 281.
    Bazarganzadeh, Mahmoudreza
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Matematiska institutionen, Analys och tillämpad matematik.
    Bozorgnia, Farid
    Numerical Approximation of One Phase Quadrature Domains2013Inngår i: Numerical Methods for Partial Differential Equations, ISSN 0749-159X, E-ISSN 1098-2426, Vol. 29, nr 5, 1709-1728 s.Artikkel i tidsskrift (Annet vitenskapelig)
    Abstract [en]

    In this work, we present two numerical schemes for a free boundary problem called one phase quadrature domain. In the first method by applying the proprieties of given free boundary problem, we derive a method that leads to a fast iterative solver. The iteration procedure is adapted in order to work in the case when topology changes. The second method is based on shape reconstruction to establish an efficient Shape-Quasi-Newton-Method. Various numerical experiments confirm the efficiency of the derived numerical methods.

  • 282.
    Beckius, Peter
    et al.
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Hübel, Alexander
    Linköpings universitet, Institutionen för ekonomisk och industriell utveckling.
    Vädrets påverkan på försäljningen inom svensk dagligvaruhandel: En studie om vädrets påverkan på ICA:s försäljning2010Independent thesis Advanced level (degree of Master (Two Years)), 20 poäng / 30 hpOppgave
    Abstract [ar]

    ICA is the largest general dealer in the Swedish market as well as the largest supplier to the independent ICA-dealers. The principal and one of the biggest stakeholders of this thesis is the department Supply Chain Development who is responsible for the development of ICA’s Supply Chain.

    The purpose of this study is to examine how ICA’s sales are affected by weather and to make recommendations on how ICA should proceed with its work regarding this issue. By leveraging their forecasts by including weather, ICA hopes that their logistical metrics amount of spoilage, service levels and number of inventory days will improve. This thesis describes how ICA is working with weather currently, and furthermore it discusses the existing literature within this area. Extensive statistical surveys have been conducted in order to identify the products that are affected by weather, and to examine how they are affected by different weather variables. Finally, the thesis gives recommendations to ICA on how they can improve their forecasting by taking this study’s results into account.

    Presently ICA has no consistent approach when it comes to considering weather’s impact on sales. Each individual product planner uses his own experience and gut feeling and there is no central guidance or other quantitative information there to help them.

    This thesis is organised around two major statistical studies. First, a correlation study examines the correlation between sales and deviation from mean temperature. The weather parameter was selected following recommendations from earlier studies and from SMHI - the national weather institute in Sweden. The study was conducted on ICA’s entire assortment and identified which items that were affected by weather. These turned out to be about a hundred in number and were affected mainly during the summer; however a few items were also affected in the winter. Most of the affected items were rather logical regarding weather’s effects on sales and have also been pointed out by planners as products that are likely to be affected by weather. Following that, several regression analyses were conducted on the selected weather affected assortment.

    The regression analyses were conducted with various combinations of one or more weather parameters as explanatory variables. Surprisingly, in most cases the deviation from mean temperature alone was the parameter that best explained the variance in sales figures. The result or output of this thesis is a value for the expected change in sales for a selected assortment, given a change in deviation from mean temperature.

    The recommendations given at the end of this thesis explains how ICA in a simple and cost effective way could implement the study's results in their daily work. The proposal is to divide the work by what should be done centrally by the forecasting department, and by what should be done individually by each planner. The forecasting department should regularly collect weather forecasts over different time periods, calculate the deviation from mean temperature and distribute it to the supply planner. After that, it is up to the supply planners on how to best take advantage of this information by taking into account other unique factors affecting each category, such as campaigns, holidays and daily indexes that in many cases have more effect on sales than the weather.

  • 283.
    Beckman, Anders
    et al.
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Fornberg, Bengt
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Tengvald, Arne
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    A method for acceleration of the convergence of infinite series1969Inngår i: BIT Numerical Mathematics, ISSN 0006-3835, E-ISSN 1572-9125, Vol. 9, 78-80 s.Artikkel i tidsskrift (Annet vitenskapelig)
  • 284.
    Beermann, Marie
    et al.
    Linnéuniversitetet, Fakultetsnämnden för hälsa, socialt arbete och beteendevetenskap, Institutionen för pedagogik, psykologi och idrottsvetenskap, PPI.
    Eriksson, Kerstin
    Linnéuniversitetet, Fakultetsnämnden för hälsa, socialt arbete och beteendevetenskap, Institutionen för pedagogik, psykologi och idrottsvetenskap, PPI.
    Vardagsmatematik: Pedagogers gruppsamtal om vardagsmatematiken i de tidigare skolåren2011Independent thesis Advanced level (professional degree), 10 poäng / 15 hpOppgave
    Abstract [sv]

    Syftet med vår studie var att synliggöra hur pedagoger som undervisar i grundskolans tidiga år samtalar om undervisningen av matematikens användning i vardagen utifrån den socio­kulturella teorin. Gruppsamtalen utgick från rubrikerna konkretisering, individ­uali­se­ring, mate­matik och språk samt matematiksvårigheter kopplade till vardagsmatematiken. Vi använ­de oss av fokusgrupper som undersökningsinstrument. I studien ingick 13 peda­goger som alla undervisade i matematik på skolans lågstadium. Deltagarna i studien var verk­samma på fyra olika skolor i två olika kommuner.

    Undersökningens resultat bearbetades utifrån en hermeneutisk innehållsanalys. I resultatet synliggörs en omfattande och medveten undervisning kring vardagsmatematiken hos de med­­verkande pedagogerna. Det som upplevs som hinder eller skapande av möjligheter är resurstilldelningen både materiellt och personellt. Gruppstorlek och gruppsammansättning upp­levs också som avgörande för en undervisning som lever upp till pedagogernas ambi­tioner. Konkretiseringen ges en stor betydelse för att fånga och förklara den abstrakta mate­matiken. Individualiseringen ses av pedagogerna som nödvändig för att få med sig alla elev­erna i matematikundervisningens gemenskap och för att alla elever ska nå målen. Den sam­talande matematiken beskrivs som ovärderlig för elevernas tänkande och därmed för­ståelse och lärandet. Det framgår att för elever med matematiska svårigheter är det konkreta materi­alet, tid tillsammans med pedagog och ett varierat undervisningssätt faktorer som skapar för­utsättningar för lärande. 

  • 285. Beilina, Larisa
    et al.
    Samuelsson, Klas
    Åhlander, Krister
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    A hybrid method for the wave equation2001Rapport (Annet vitenskapelig)
  • 286. Beilina, Larisa
    et al.
    Samuelsson, Klas
    Åhlander, Krister
    Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Avdelningen för teknisk databehandling. Uppsala universitet, Teknisk-naturvetenskapliga vetenskapsområdet, Matematisk-datavetenskapliga sektionen, Institutionen för informationsteknologi, Numerisk analys.
    Efficiency of a hybrid method for the wave equation2001Inngår i: Finite Element Methods: Three-dimensional problems, Tokyo: Gakkotosho , 2001, 9-21 s.Konferansepaper (Fagfellevurdert)
  • 287.
    Belov, I.
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik.
    Alavizadeh, Z.
    Lindgren, M.
    Application of engineering optimization to evaluate heating-based humidity management in electronics enclosures2011Inngår i: Electronic Environment Konferens & Mässa 2011, Stockholm Älvsjö,5-6 April 2011, Invited speech, 2011, 161-162 s.Konferansepaper (Annet vitenskapelig)
  • 288.
    Belov, Ilja
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Anti-Moisture Methodology for Electronics Enclosures in Harsh Storage Environments2008Konferansepaper (Annet vitenskapelig)
  • 289.
    Belov, Ilja
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Evaluation of Anti-Moisture Measures in Electronics Enclosure: Application of CFD Modelling2009Konferansepaper (Annet vitenskapelig)
  • 290.
    Belov, Ilja
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Humidity Management in Electronics Enclosure under Severe Climatic Conditions2008Konferansepaper (Annet vitenskapelig)
  • 291.
    Belov, Ilja
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Optimization of PCB Heater Heating Profile for Power-efficient Humidity Management in Electronics Enclosures: OPTIMUS Worldwide User Meeting 2010, Antwerp, Belgium, November 22-23, 20102010Annet (Annet vitenskapelig)
  • 292.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Bespalov, Michail
    Klochkova, Ludmila
    Kuleshov, Alexander
    Suzan, Dmitriy
    Tishkin, Vladimir
    Транспортная модель распространения газообразных примесей в атмосфере города = Transport model of gas impurities spread processes in urban area2000Inngår i: Математическое моделирование: (Mathematical Modelling), ISSN 0234-0879, Vol. 12, nr 11, 38-46 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 293.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Bespalov, Michail
    Klochkova, Ludmila
    Pavlova, Natalya
    Suzan, Dmitriy
    Tishkin, Vladimir
    Сравнение моделей распространения загрязнений в атмосфере = Comparative Analysis of models of pollutions spreading in atmosphere1999Inngår i: Математическое моделирование: (Mathematical Modelling), ISSN 0234-0879, Vol. 11, nr 8, 52-64 s.Artikkel i tidsskrift (Fagfellevurdert)
  • 294.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Lindgren, Mats
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Bergner, Fredrik
    Bornoff, Robin
    CFD aided reflow oven profiling for PCB preheating in a soldering process2007Inngår i: Proceedings of the 8th International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Micro-Electronics and Micro-Systems: EuroSimE 2007, Piscataway, NJ.: IEEE , 2007, 535-542 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A CFD-aided reflow oven profile prediction algorithm has been developed and applied to modelling of preheating of a PCB with non-uniform distribution of component thermal mass in a forced air convection solder reflow oven. The iterative algorithm combines an analytic approach with CFD modelling. It requires an experimentally validated CFD model of the solder reflow oven and a CFD model of the PCB as main inputs. Results of computational experiments have been presented to reveal good agreement between predicted PCB profiles and corresponding CFD calculations. Application guidelines contained in the description of the algorithm will assist potential users both during the virtual prototyping phase of a PCB including designing for assembly and in the phase of reflow oven profiling.

  • 295.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Lindgren, Mats
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Bergner, Fredrik
    Bornoff, Robin
    CFD aided reflow oven profiling for PCB preheating in a soldering process: Part 1(2)2007Inngår i: Electronic Environment, nr 3, 25-28 s.Artikkel i tidsskrift (Annet vitenskapelig)
  • 296.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Lindgren, Mats
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Bergner, Fredrik
    Bornoff, Robin
    CFD aided reflow oven profiling for PCB preheating in a soldering process: Part 2(2)2007Inngår i: Electronic Environment, nr 4, 25-27 s.Artikkel i tidsskrift (Annet vitenskapelig)
  • 297.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Lindgren, Mats
    Ryden, Jan
    Alavizadeh, Zahra
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    CFD Assisted Design Evaluation and Experimental Verification of a Logic-Controlled Local PCB Heater for Humidity Management in Electronics Enclosure2010Inngår i: IEEE EuroSimE 2010, 26-28 April, Bordeaux, France, 2010Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Humidity management of commercial-of-the-shelf electronic components in non-controlled climatic environments can be realized e.g. by introducing a local printed circuit board heater. By choosing appropriate size and location of the heater plate in the vicinity of the critical electronic packages, and utilizing logic control function, it is possible to improve the quality of local humidity management and reduce power consumption of the heater, which is important especially in case of battery driven portable or vehicle mounted devices. A computational fluid dynamics assisted methodology has been developed to determine the best feasible design of the heater, followed by experimental verification of the constructed logic controlled heater. The experiment has been performed in a harsh climatic environment including temperature variation from +33°C to +40°C, and relative humidity variation from 54% to 80%. Analysis of the experimental %RH and temperature curves as well as power profile of the heater has confirmed the feasibility of the chosen approach to maintain greater than 9°C difference between the electronics package surface temperature and the local dew point temperature, by applying discrete power pulses with the amplitude less than 6 W.

  • 298.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Rydén, Jan
    Lindblom, Joakim
    Zhang, Yafan
    Hansson, T
    Bergner, Fredrik
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Application of CFD Modelling for Energy Efficient Humidity Mangement of an Electronics Enclosure in Storage under Severe Climatic Conditions2008Inngår i: International Conference on Thermal, Mechanical and Multi-Physics Simulation and Experiments in Microelectronics and Micro-Systems, 2008: EuroSimE 2008., IEEE , 2008, 430-437 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    A CFD modelling methodology including experimental validation has been developed and applied for investigation of anti-moisture measures in a non- hermetic electronics enclosure containing a number of printed circuit boards, and placed in a severe storage environment. In the climatic test the temperature and the relative humidity have been varried from +33degC to +71degC and from 14% to 80%, respectively. Enclosure heater solutions have been parametrically studied by simulation. A heating strategy involving various power levels has been determined, which is just sufficient to maintain the internal relative humidity below 60%, thereby reducing the risk for dew formation on the electronics assembly.

  • 299.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Wingbrant, Helena
    Spetz, Anita-Lloyd
    Sundgren, Hans
    Thuner, Bo
    Svenningstorp, Henrick
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Thermal and flow analysis of SiC-based gas sensors for automotive applications2004Inngår i: Proceedings of the 5th International Conference on Thermal and Mechanical Simulation and Experiments in Microelectronics and Microsystems, 2004: EuroSimE 2004., IEEE , 2004, 475-482 s.Konferansepaper (Fagfellevurdert)
    Abstract [en]

    Different block and tube mounting alternatives for SiC-based gas sensors were studied by means of temperature measurements and simulation of heat transfer and gas flow for steady state conditions. The most preferable tube mounting design was determined. Simulation-based guidelines were developed for designing tube-mounted gas sensors in the exhaust pipes of diesel and petrol engines, taking into account thermal constraints and flow conditions.

  • 300.
    Belov, Ilja
    et al.
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    Wingbrant, Helena
    Spetz, Anita-Lloyd
    Sundgren, Hans
    Thuner, Bo
    Svenningstorp, Henrik
    Leisner, Peter
    Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsmiljö Material och tillverkning - Ytteknik. Högskolan i Jönköping, Tekniska Högskolan, JTH. Forskningsområde Robusta inbyggda system.
    CFD analysis of packaging and mounting solutions for SiC-based gas sensors in automotive applications2006Inngår i: Sensor Letters, ISSN 1546-198X, Vol. 4, nr 1, 29-37 s.Artikkel i tidsskrift (Fagfellevurdert)
    Abstract [en]

    Simulation-based guidelines were developed for designing tube-mounted gas sensors in the exhaust pipes of diesel and petrol engines, taking into account thermal constraints and gas flow conditions. Different block and tube mounting alternatives for SiC-based gas sensors were studied by means of temperature measurements and simulation of steady state heat transfer and gas flow. Design variables included the number of fins in the heat sink mounted on the inlet tube, the inlet construction, the mounting tube orientation, and the micro-heater substrate placement inside the mounting tube. The most preferable tube mounting design was determined with respect to the thermal performance of the sensor structure and with respect to the gas flow parameters, which are important for the sensor's selectivity, sensitivity and response time.

3456789 251 - 300 of 3506
RefereraExporteraLink til resultatlisten
Permanent link
Referera
Referensformat
  • apa
  • ieee
  • modern-language-association-8th-edition
  • vancouver
  • Annet format
Fler format
Språk
  • de-DE
  • en-GB
  • en-US
  • fi-FI
  • nn-NO
  • nn-NB
  • sv-SE
  • Annet språk
Fler språk
Utmatningsformat
  • html
  • text
  • asciidoc
  • rtf