Sökning: "dispersion analysis"

Visar resultat 1 - 5 av 247 avhandlingar innehållade orden dispersion analysis.

  1. 1. Numerical analysis and simulation of stochastic partial differential equations with white noise dispersion

    Författare :André Berg; David Cohen; Per Åhag; Guillaume Dujardin; Ludovic Goudenège; Umeå universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; stochastic partial differential equation; mathematics; numerical analysis; numerical scheme; time integrator; convergence analysis; blowup; critical exponent; nonlinear Schrödinger equation; Manakov equation; Benjamin-Bona-Mahony equation; BBM equation; stochastic; random; dispersion; white noise dispersion; finite difference; pseudospectral; code; matlab; exponential integrator; splitting integrator; convergence in probability; Mathematics; matematik; Numerical Analysis; numerisk analys;

    Sammanfattning : This doctoral thesis provides a comprehensive numerical analysis and exploration of several stochastic partial differential equations (SPDEs). More specifically, this thesis investigates time integrators for SPDEs with white noise dispersion. LÄS MER

  3. 2. Error analysis of summation-by-parts formulations : Dispersion, transmission and accuracy

    Författare :Viktor Linders; Jan Nordström; Marco Kupiainen; Mark Carpenter; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : In this thesis we consider errors arising from finite difference operators on summation-by-parts (SBP) form, used in the discretisation of partial differential equations. The SBP operators are augmented with simultaneous-approximation-terms (SATs) to weakly impose boundary conditions. LÄS MER

  4. 3. Electromagnetic Dispersion Modeling and Analysis for Power Cables

    Författare :Stefan Gustafsson; Sven Nordebo; Alexander Nosich; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; power cable; electromagnetic model; dispersion relation; asymptotic analysis; sensitivity analysis;

    Sammanfattning : This thesis addresses electromagnetic wave propagation in power cables. It consists of five papers, where the three first papers are based on one and the same model, and the last two papers are based on a similar but slightly different model. LÄS MER

  5. 4. Electromagnetic dispersion modeling and analysis for HVDC power cables

    Författare :Stefan Gustafsson; Sven Nordebo; Martin Norgren; Linnéuniversitetet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; HVDC power cables; electromagnetic model; TDR measurement; sensitivity analysis; dispersion relation; propagation constant; low-frequency asymptotics;

    Sammanfattning : Derivation of an electromagnetic model, regarding the wave propagation in a very long (10 km or more) High Voltage Direct Current (HVDC) power cable, is the central part of this thesis. With an existing “perfect” electromagnetic model there are potentially a wide range of applications. LÄS MER

  7. 5. Theoretical Investigation into Longitudinal Dispersion in Natural Rivers — A Scaling Dispersion Model

    Författare :Zhi-Qiang Deng; Avdelningen för Teknisk vattenresurslära; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; soil mechanics; Väg- och vattenbyggnadsteknik; Environmental technology; pollution control; Miljöteknik; kontroll av utsläpp; offshore technology; hydraulic engineering; Civil engineering; Scaling dispersion.; Parameter estimation; Numerical scheme; Dispersion coefficient; Natural river;

    Sammanfattning : Using a broad variety of scientific methods this dissertation systematically investigates the fundamental mechanisms underlying the dispersion processes in natural rivers and their mathematical descriptions in a geometrical framework. Emphasis is on the geometrical variations and irregularities of a natural river and their scales. LÄS MER