Sökning: "wave equation"

Visar resultat 21 - 25 av 208 avhandlingar innehållade orden wave equation.

  1. 21. The Dirac Equation: Numerical and Asymptotic Analysis

    Författare :Hasan Almanasreh; Göteborgs universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Dirac operator; eigenvalue problem; finite element method; spurious eigenvalues; Petrov-Galerkin; cubic Hermite basis functions; stability parameter; meshfree method; $hp$-cloud; intrinsic enrichment; G-convergence; $ Gamma$-convergence; scattering theory; identification; wave operator; stationary approach; Dirac operator;

    Sammanfattning : The thesis consists of three parts, although each part belongs to a specific subject area in mathematics, they are considered as subfields of the perturbation theory. The main objective of the presented work is the study of the Dirac operator; the first part concerns the treatment of the spurious eigenvalues in the computation of the discrete spectrum. LÄS MER

  3. 22. AC Josephson effect in superconducting d-wave junctions

    Författare :Tomas Löfwander; Chalmers tekniska högskola; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; dc and ac Josephson effect; superconductivity; Bogoliuboov-de Gennes equation; Andreev reflection; superconducting junctions; d-wave superconductivity; high-Tc superconductivity;

    Sammanfattning : .... LÄS MER

  4. 23. On Half-Space and Shock-Wave Problems for Discrete Velocity Models of the Boltzmann Equation

    Författare :Niclas Bernhoff; Alexander Bobylev; Giuseppe Toscani; Karlstads universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boltzmann equation; discrete velocity models; boundary value problems; shock waves; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

    Sammanfattning : We study some questions related to general discrete velocity (with arbitrarily number of velocities) models (DVMs) of the Boltzmann equation. In the case of plane stationary problems the typical DVM reduces to a dynamical system (system of ODEs). Properties of such systems are studied in the most general case. LÄS MER

  5. 24. Fast wave heating and current drive in tokamaks

    Författare :Martin Laxåback; Torbjörn Hellsten; Raymond Koch; KTH; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Tokamak; JET; ITER; thermonuclear fusion; fast wave; heating; current drive; ion cyclotron resonance; polychromatic; finite orbit widths; RF-induced transport; neutral beam injection; fusion born alpha particles; magnetosonic eigenmodes; parasitic absorption; modelling; weighted Monte Carlo scheme; Fysik; Physics; Fysik;

    Sammanfattning : This thesis concerns heating and current drive in tokamak plasmas using the fast magnetosonic wave in the ion cyclotron range of frequencies. Fast wave heating is a versatile heating method for thermonuclear fusion plasmas and can provide both ion and electron heating and non-inductive current drive. LÄS MER

  7. 25. Properties of wave-front sets and non-tangential convergence

    Författare :Karoline Johansson; Joachim Toft; Luigi Rodino; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Fourier Banach spaces; Generalized free time-dependent Schrödinger equation; Micro-local; Modulation spaces; Non-tangential convergence; Pseudo-differential operators; Regularity; Wave-front sets.; Mathematical analysis; Analys; Matematik; Mathematics;

    Sammanfattning : In this thesis we consider regularity properties for solutions to partial differential equations and pseudo-differential equations. The thesis mainly concerns wave-front sets and micro-local properties. LÄS MER