Sökning: "laplace operator"

Visar resultat 1 - 5 av 29 avhandlingar innehållade orden laplace operator.

  1. 1. Heterogeneous Materials - Diffusion, Laplace spectrum and NMR

    Författare :Matias Nordin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; perturbation; nmr; diffusion; laplace operator; spectrum; heterogeneous materials;

    Sammanfattning : Relations to the effective diffusion constant and the relaxation rate of the time-dependent diffusion coefficient for porous systems are derived from the Laplace operator spectrum. The Padé approximation is then explained in terms of the Laplace operator spectrum. LÄS MER

  3. 2. Heterogeneous Materials - Diffusion, Laplace Spectrum, and Nuclear Magnetic Resonance

    Författare :Matias Nordin; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; eigenfunctions; eigenvalues; propagator; diffusion; Laplace operator; Nuclear Magnetic Resonance;

    Sammanfattning : In this thesis diffusion in heterogeneous materials is studied using spectral analysisof the Laplace operator. Relations to the effective diffusion constant and therelaxation rate of the time-dependent diffusion coefficient for porous systems arederived from the Laplace operator’s spectrum. LÄS MER

  4. 3. Boundary Behavior of p-Laplace Type Equations

    Författare :Benny Avelin; Kaj Nyström; Steve Hofmann; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; p-Laplace; Boundary Harnack inequality; A-harmonic; Ahlfors regularity; NTA-domains; Martin boundary; Reifenberg flat; Approximable by Lipschitz graphs; Subelliptic; Carleson estimate; Mathematics; Matematik;

    Sammanfattning : This thesis consists of six scientific papers, an introduction and a summary. All six papers concern the boundary behavior of non-negative solutions to partial differential equations.Paper I concerns solutions to certain p-Laplace type operators with variable coefficients. LÄS MER

  5. 4. Inverse Problems for Graph Laplacians

    Författare :Marlena Nowaczyk; Matematik LTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Spectral theory; Laplace operator; Trace formula; Quantum graphs;

    Sammanfattning : This thesis is devoted to inverse spectral problems for Laplace operators on metric graphs, and it is based on the following papers: Paper I - P. Kurasov and M. Nowaczyk 2005 Inverse spectral problem for quantum graphs J. Phys. LÄS MER

  7. 5. Studies on instability and optimal forcing of incompressible flows

    Författare :Mattias Brynjell-Rahkola; Dan S. Henningson; Ardeshir Hanifi; Philipp Schlatter; François Gallaire; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; hydrodynamic stability; optimal forcing; resolvent operator; Laplace preconditioner; spectral element method; eigenvalue problems; inverse power method; direct numerical simulations; Falkner–Skan–Cooke boundary layer; localized roughness; crossflow vortices; Blasius boundary layer; localized suction; helical vortices; lid-driven cavity; cylinder flow; Teknisk mekanik; Engineering Mechanics;

    Sammanfattning : This thesis considers the hydrodynamic instability and optimal forcing of a number of incompressible flow cases. In the first part, the instabilities of three problems that are of great interest in energy and aerospace applications are studied, namely a Blasius boundary layer subject to localized wall-suction, a Falkner–Skan–Cooke boundary layer with a localized surface roughness, and a pair of helical vortices. LÄS MER