Sökning: "numerical propagation"

Visar resultat 1 - 5 av 253 avhandlingar innehållade orden numerical propagation.

  1. 1. Cost Propagation - Numerical Propagation for Optimization Problems

    Författare :Birgit Grohe; Chalmers University of Technology; []
    Nyckelord :optimization; numerical propagation; Cost propagation;

    Sammanfattning : In this thesis, we investigate Cost Propagation,an approach to numerical propagation for optimization problems, where we combine ideas from both Constraint Programming and Combinatorial Optimization. We consider discrete optimization problems with binary variables that can be expressed in the model max_x sum_k g_k(x^k)where the terms g_k(x^k) are distinct arbitrary functions over subsets x^k of x. LÄS MER

  2. 2. Numerical Methods for Wave Propagation : Analysis and Applications in Quantum Dynamics

    Författare :Emil Kieri; Sverker Holmgren; Vasile Gradinaru; Hans O. Karlsson; Tobias Jahnke; Uppsala universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; computational wave propagation; quantum dynamics; time-dependent Schrödinger equation; spectral methods; Gaussian beams; splitting methods; low-rank approximation; Scientific Computing; Beräkningsvetenskap;

    Sammanfattning : We study numerical methods for time-dependent partial differential equations describing wave propagation, primarily applied to problems in quantum dynamics governed by the time-dependent Schrödinger equation (TDSE). We consider both methods for spatial approximation and for time stepping. LÄS MER

  3. 3. A Wave Expansion Method for Aeroacoustic Propagation

    Författare :Johan Hammar; Gunilla Efraimsson; Ciarán J. O'Reilly; Wim De Roeck; KTH; []
    Nyckelord :ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Sound propagation; Sound generation; Aeroacoustics; Aerodynamics; Computational fluid dynamics; Computational aeroacoustics; Numerical methods; Lighthill; Curle; Ffowcs Williams and Hawkings; Frequency-domain propagation; Wave expansion method.; Vehicle and Maritime Engineering; Farkostteknik;

    Sammanfattning : Although it is possible to directly solve an entire flow-acoustics problem in one computation, this approach remains prohibitively large in terms of the computational resource required for most practical applications. Aeroacoustic problems are therefore usually split into two parts; one consisting of the source computation and one of the source propagation. LÄS MER

  4. 4. Numerical simulation of crack propagation and wear in rails

    Författare :Jim Brouzoulis; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; wear; Rolling Contact Fatigue; crack propagation; railway mechanics;

    Sammanfattning : This thesis is concerned with rail deterioration due to Rolling Contact Fatigue (RCF) and wear. Focus lies primarily on numerical modelling and prediction, with the long-term objective of developing tools to be used for specifications and planning of rail maintenance. LÄS MER

  5. 5. Lithium-ion Battery Safety - Assessment by Abuse Testing, Fluoride Gas Emissions and Fire Propagation

    Författare :Carl Fredrik Larsson; Chalmers University of Technology; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; ENGINEERING AND TECHNOLOGY; fire; thermal runaway; gas emission; gas explosion; propagation; safety; abuse testing; Lithium-ion; cell case explosion; hydrogen fluoride;

    Sammanfattning : Lithium-ion batteries offer high energy and power densities as well as long life time but have a more narrow stability window compared to other battery types and contain reactive and flammable materials. In case of overheating the battery cell can release gas (vent) and, at temperatures of about 150-200 °C, a so called thermal runaway can occur, that is a rapid self-heated temperature increase which is typically accompanied with a large release of smoke and gas, fire and a potential cell case explosion or gas explosion. LÄS MER