Search for dissertations about: "equation"

Showing result 6 - 10 of 1354 swedish dissertations containing the word equation.

  1. 6. Approximating Stochastic Partial Differential Equations with Finite Elements: Computation and Analysis

    Author : Andreas Petersson; Chalmers University of Technology; []
    Keywords : 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

  2. 7. Macroscopic Volume and Free Volume of Polymer Blends and Pressure-densified Polymers

    Author : Marcus Schmidt; Chalmers University of Technology; []
    Keywords : free-volume theories; refractive index; Lorentz-Lorenz equation; loss tangent; Avrami equation; freezing fractions; copolymers; polymer blends; pressure dilatometry; Tait equation of state; free-volume distributions; pressure-densified polymers; entropy of melting; dynamic-mechanical analysis; positronium; positron annihilation; free volume; cavity size; polymers; bulk modulus; PVT; phase separation; compressibility; thermal expansivity;

    Abstract : The macroscopic volume V as a function of pressure P and temperature T is obtained from PVT measurements. PVT data is sensitive to the state of polymers and changes therein. Moreover, PVT data gives access to the free-volume fraction. READ MORE

  3. 8. Analytical vortex solutions to Navier-Stokes equation

    Author : Henrik Tryggeson; Mats Lyberg; Maarten Brons; Växjö universitet; []
    Keywords : ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; conical vortex; Navier-Stokes equation; analytical solution; 2-D vortices; turbulence; vortex ring; stretched vortex; coherent structures; Fluid mechanics; Strömningsmekanik;

    Abstract : Fluid dynamics considers the physics of liquids and gases. This is a branch of classical physics and is totally based on Newton's laws of motion. Nevertheless, the equation of fluid motion, Navier-Stokes equation, becomes very complicated to solve even for very simple configurations. READ MORE

  4. 9. On the Matrix Riccati Equation

    Author : Krister Mårtensson; []

    Abstract : The matrix Riccati equation appears in many optimal control and filtering problems. In this paper the Riccati equation is studied from an algebraic point of view, and the results are applied on optimal control of linear time invariant systems with quadratic loss... READ MORE

  5. 10. Numerical Vlasov–Maxwell Modelling of Space Plasma

    Author : Bengt Eliasson; Bertil Gustafsson; Bo Thidé; Anders Bondeson; Uppsala universitet; []
    Keywords : NATURAL SCIENCES; NATURVETENSKAP; NATURVETENSKAP; NATURAL SCIENCES; Vlasov equation; Maxwell equation; Fourier method; outflow boundary; domain decomposition; Numerical Analysis; Numerisk analys;

    Abstract : The Vlasov equation describes the evolution of the distribution function of particles in phase space (x,v), where the particles interact with long-range forces, but where shortrange "collisional" forces are neglected. A space plasma consists of low-mass electrically charged particles, and therefore the most important long-range forces acting in the plasma are the Lorentz forces created by electromagnetic fields. READ MORE