Sökning: "Time adaptivity"

Visar resultat 16 - 20 av 52 avhandlingar innehållade orden Time adaptivity.

  1. 16. Adaptive finite element methods for multiphysics problems

    Författare :Fredrik Bengzon; Mats Larson; Harald van Brummelen; Umeå universitet; []
    Nyckelord :finite element methods; multiphysics; a posteriori error estimation; duality; adaptivity; discontinuous Galerkin; fractional step methods;

    Sammanfattning : In this thesis we develop and analyze the performance ofadaptive finite element methods for multiphysics problems. Inparticular, we propose a methodology for deriving computable errorestimates when solving unidirectionally coupled multiphysics problemsusing segregated finite element solvers. LÄS MER

  3. 17. Efficient Adaptive Algorithms for an Electromagnetic Coefficient Inverse Problem

    Författare :John Bondestam Malmberg; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coefficient inverse problem; inverse scattering; Maxwell’s equations; approximate global convergence; finite element method; adaptivity; ; a posteriori error analysis;

    Sammanfattning : This thesis comprises five scientific papers, all of which are focusing on the inverse problem of reconstructing a dielectric permittivity which may vary in space inside a given domain. The data for the reconstruction consist of time-domain observations of the electric field, resulting from a single incident wave, on a part of the boundary of the domain under consideration. LÄS MER

  4. 18. A Two-stage Numerical Procedure for an Inverse Scattering Problem

    Författare :John Bondestam Malmberg; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coefficient inverse problem; inverse scattering; backscattering data; approximate global convergence; finite element method; adaptivity; a posteriori error analysis; a posteriori error analysis;

    Sammanfattning : In this thesis we study a numerical procedure for the solution of the inverse problem of reconstructing location, shape and material properties (in particular refractive indices) of scatterers located in a known background medium. The data consist of time-resolved backscattered radar signals from a single source position. LÄS MER

  5. 19. Towards adaptive mesh refinement in Nek5000

    Författare :Nicolas Offermans; Philipp Schlatter; Adam Peplinski; Paul Fischer; Chris Cantwell; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Error estimators; mesh refinement; adaptivity; spectral element method; algebraic multigrid method; Engineering Mechanics; Teknisk mekanik;

    Sammanfattning : The development of adaptive mesh refinement capabilities in the field of computational fluid dynamics is an essential tool for enabling the simulation of larger and more complex physical problems. While such techniques have been known for a long time, most simulations do not make use of them because of the lack of a robust implementation. LÄS MER

  7. 20. A Formalized Approach to Multi-View Components for Embedded Systems : Applied to Tool Integration, Run-Time Adaptivity and Architecture Exploration

    Författare :Magnus Persson; Martin Törngren; De-Jiu Chen; Werner Damm; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; view; viewpoint; architecture; component; view integration; architecture exploration; component-based development; multi-view modeling; model-based design; CESAR; DySCAS; ESPRESSO;

    Sammanfattning : Development of embedded systems poses an increasing challenge fordevelopers largely due to increasing complexity. Several factors contribute tothe complexity challenge:• the number of extra-functional properties applying to embedded systems,such as resource usage, timing effects, safety. LÄS MER