Sökning: "wave equation"

Visar resultat 21 - 25 av 160 avhandlingar innehållade orden wave equation.

  1. 21. Fast wave heating and current drive in tokamaks

    Detta är en avhandling från Stockholm : KTH

    Författare :Martin Laxåback; KTH.; [2005]
    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; NATURAL SCIENCES Physics; NATURVETENSKAP 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

  2. 22. Properties of wave-front sets and non-tangential convergence

    Detta är en avhandling från Växjö, Kalmar : Linnaeus University Press

    Författare :Karoline Johansson; Linnéuniversitetet.; [2011]
    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.; MATHEMATICS Algebra; geometry and mathematical analysis Mathematical analysis; MATEMATIK Algebra; geometri och analys 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

  3. 23. Finite Difference and Discontinuous Galerkin Methods for Wave Equations

    Detta är en avhandling från Uppsala : Acta Universitatis Upsaliensis

    Författare :Siyang Wang; Uppsala universitet.; Uppsala universitet.; [2017]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Wave propagation; Finite difference method; Discontinuous Galerkin method; Stability; Accuracy; Summation by parts; Normal mode analysis; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

    Sammanfattning : Wave propagation problems can be modeled by partial differential equations. In this thesis, we study wave propagation in fluids and in solids, modeled by the acoustic wave equation and the elastic wave equation, respectively. LÄS MER

  4. 24. Geometric Methods for some Nonlinear Wave Equations

    Detta är en avhandling från Centre for Mathematical Sciences, Lund University

    Författare :Jonatan Lenells; Lund University.; Lunds universitet.; [2006]
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Natural science; Geodesic flow; Nonlinear wave equations; Geometric methods; Naturvetenskap;

    Sammanfattning : A number of results related to the geometric interpretation of some dispersive nonlinear wave equations are presented. It is first described how some well-known shallow water equations arise geometrically as Euler equations for the geodesic flow on the Virasoro group endowed with certain right-invariant metrics. LÄS MER

  5. 25. Wave Splitting and Effective Boundary Conditions for Structural Elements

    Detta är en avhandling från Centre for Mathematical Sciences, Lund University

    Författare :Martin Johansson; [2004]
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; approximate boundary condition; Mindlin plate; Timoshenko beam; thin plates; cylindrical coordinates; series approximation; wave splitting; dispersion; fluid-loaded plate; Biot;

    Sammanfattning : The subject of this thesis is twofold. The first part concerns the wave splitting of structural elements. The second part concerns approximate boundary conditions for fluid-loaded thin plates. Wave splitting is a mathematical tool for the formulation of scattering problems in the time domain that aims at solving inverse problems, e. LÄS MER