Search for dissertations about: "numerical analysis"

Showing result 6 - 10 of 1127 swedish dissertations containing the words numerical analysis.

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

    Author : Hasan Almanasreh; Göteborgs universitet.; Gothenburg University.; [2012]
    Keywords : 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;

    Abstract : 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. READ MORE

  2. 7. Approximating Stochastic Partial Differential Equations with Finite Elements: Computation and Analysis

    University dissertation from ; Chalmers tekniska högskola; Gothenburg

    Author : Andreas Petersson; [2019]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Lévy process; Lyapunov equation; white noise; finite element method; multilevel Monte Carlo; Monte Carlo; multiplicative noise; asymptotic mean square stability; stochastic heat equation; covariance operator; weak convergence; generalized Wiener process; numerical approximation; stochastic wave equation; Stochastic partial differential equations;

    Abstract : Stochastic partial differential equations (SPDE) must be approximated in space and time to allow for the simulation of their solutions. In this thesis fully discrete approximations of such equations are considered, with an emphasis on finite element methods combined with rational semigroup approximations. READ MORE

  3. 8. Global stability analysis of complex fluids

    University dissertation from Stockholm : KTH Royal Institute of Technology

    Author : Iman Lashgari; KTH.; KTH.; [2013]
    Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; non-Newtonian flow; Carreau model; Oldroyd-B model; FENE-P model; modal analysis; nonmodal analysis; sensitivity analysis;

    Abstract : The main focus of this work is on the non-Newtonian effects on the inertial instabilities in shear flows. Both inelastic (Carreau) and elastic models (Oldroyd-B and FENE-P) have been employed to examine the main features of the non-Newtonian fluids; shear-thinning, shear-thickening and elasticity. READ MORE

  4. 9. A numerical study of two-fluid models for dispersed two-phase flow

    University dissertation from Stockholm : KTH

    Author : Reynir Levi Gudmundsson; KTH.; [2005]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Numerical analysis; two-phase flow; two-fluid mode; well-posedness; numerical experiments; Numerisk analys; MATHEMATICS Applied mathematics Numerical analysis; MATEMATIK Tillämpad matematik Numerisk analys;

    Abstract : In this thesis the two-fluid (Eulerian/Eulerian) formulation for dispersed two-phase flow is considered. Closure laws are needed for this type of models. We investigate both empirically based relations, which we refer to as a nongranular model, and relations obtained from kinetic theory of dense gases, which we refer to as a granular model. READ MORE

  5. 10. Non-selfadjoint operator functions

    University dissertation from Umeå : Umeå universitet

    Author : Axel Torshage; Umeå universitet.; [2017]
    Keywords : NATURVETENSKAP; NATURAL SCIENCES; Non-linear spectral problem; numerical range; pseudospectrum; resolvent estimate; equivalence after extension; block operator matrices; operator functions; operator pencil; spectral divisor; joint numerical range; Mathematics; matematik;

    Abstract : Spectral properties of linear operators and operator functions can be used to analyze models in nature. When dispersion and damping are taken into account, the dependence of the spectral parameter is in general non-linear and the operators are not selfadjoint. READ MORE