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Visar resultat 1 - 5 av 208 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Numerics of Elastic and Acoustic Wave Motion

   Författare :Kristoffer Virta; Gunilla Kreiss; Anders Petersson; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite differences; stability; high order accuracy; elastic wave equation; acoustic wave equation; Beräkningsvetenskap med inriktning mot numerisk analys; Scientific Computing with specialization in Numerical Analysis;

   Sammanfattning : The elastic wave equation describes the propagation of elastic disturbances produced by seismic events in the Earth or vibrations in plates and beams. The acoustic wave equation governs the propagation of sound. LÄS MER

3. 2. High Order Symmetric Finite Difference Schemes for the Acoustic Wave Equation

   Författare :Abraham Zemui; Bertil Gustafsson; Leif Abrahamsson; Per Weinerfelt; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element method; mass lumping; high order; finite difference method; wave equation; Numerical Analysis; Numerisk analys;

   Sammanfattning : When someone speaks, or when a piano is played, sound waves are spread through the room. Physically the propagation of sound is governed by the acoustic wave equation. This thesis deals with the problem of finding solutions to this equation by numerical methods. LÄS MER

4. 3. Aspects of Wave Interaction in Nonlinear Media

   Författare :Björn Hall; Chalmers tekniska högskola; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear Schrödinger equation; incoherent solitons; partial incoherence; nonlinear wave interaction; Gross-Pitaevskii equation; modulational instability; collective dynamics; Wigner transform; nonlinear guided waves; Bose-Einstein condensation;

   Sammanfattning : Selected aspects of various types of nonlinear wave interaction are investigated. These aspects are studied in terms of models described by Nonlinear Schrödinger equations, mainly analytically and numerically, but also experimentally. LÄS MER

5. 4. Some numerical and analytical methods for equations of wave propagation and kinetic theory

   Författare :Eva Mossberg; Alexander Bobylev; Giovanni Russo; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; wave propagation; finite difference metods high order methods; Landau-Fokker-Planck equation; Monte-Carlo simulations; Boltzmann equation; hard sphere model; eigenvalue problem; MATHEMATICS; MATEMATIK; Matematik; Mathematics;

   Sammanfattning : This thesis consists of two different parts, related to two different fields in mathematical physics: wave propagation and kinetic theory of gases. Various mathematical and computational problems for equations from these areas are treated. LÄS MER

7. 5. 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 :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