Sökning: "A posteriori error estimates"

Visar resultat 11 - 15 av 35 avhandlingar innehållade orden A posteriori error estimates.

1. 11. Finite element approximation of the deterministic and the stochastic Cahn-Hilliard equation

   Författare :Ali Mesforush; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element; a priori error estimate; stochastic integral; mild solution; dual weighted residuals; a posteriori error estimate; additive noise; Wiener process; Cahn-Hilliard equation; existence; regularity; Lya- punov functional; stochastic convolution; Lya- punov functional;

   Sammanfattning : This thesis consists of three papers on numerical approximation of the Cahn-Hilliard equation. The main part of the work is concerned with the Cahn-Hilliard equation perturbed by noise, also known as the Cahn-Hilliard-Cook equation. LÄS MER

3. 12. A Two-stage Numerical Procedure for an Inverse Scattering Problem

   Författare :John Bondestam Malmberg; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coefficient inverse problem; inverse scattering; backscattering data; approximate global convergence; finite element method; adaptivity; a posteriori error analysis; a posteriori error analysis;

   Sammanfattning : In this thesis we study a numerical procedure for the solution of the inverse problem of reconstructing location, shape and material properties (in particular refractive indices) of scatterers located in a known background medium. The data consist of time-resolved backscattered radar signals from a single source position. LÄS MER

4. 13. The Finite Element Method for Fractional Order Viscoelasticity and the Stochastic Wave Equation

   Författare :Fardin Saedpanah; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; finite element method; continuous Galerkin method; linear viscoelasticity; fractional calculus; fractional order viscoelasticity; weakly singular kernel; stability; a priori error estimate; a posteriori error estimate; stochastic wave equation; additive noise; Wiener process; strong convergence.; linear viscoelasticity;

   Sammanfattning : This thesis can be considered as two parts. In the first part a hyperbolic type integro-differential equation with weakly singular kernel is considered, which is a model for dynamic fractional order viscoelasticity. In the second part, the finite element approximation of the linear stochastic wave equation is studied. LÄS MER

5. 14. Models for capturing the penetration of a diffusant concentration into rubber : Numerical analysis and simulation

   Författare :Surendra Nepal; Adrian Muntean; Nadja Ray; Karlstads universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; transport of diffusants; moving-boundary problem; finite element method; a priori and a posteriori error estimates; random walk method; two-scale coupled system; Matematik; Mathematics;

   Sammanfattning : Understanding the transport of diffusants into rubber plays an important role in forecasting the material's durability. In this regard, we study different models, conduct numerical analysis, and present simulation results that predict the evolution of the penetration front of diffusants. LÄS MER

7. 15. Adaptive Finite Element Methods for Reactive Flow Problems

   Författare :Robert Sandboge; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; convection-diffusion-reaction problems; posteriori error estimates; adaptive finite element methods; ; adaptive finite element methods;

   Sammanfattning : We present and analyze adaptive finite element methods with reliable and efficient error control for a variety of convection-diffusion-reaction problems. The adaptive methods are based on a posteriori error estimates, where the error is estimated in terms of the residual of the computed solution, the mesh size and multiplicative factors measuring certain stability properties of an associated linearized dual problem. LÄS MER