Search for dissertations about: "Error Estimates"

Showing result 1 - 5 of 280 swedish dissertations containing the words Error Estimates.

2. 1. Computational Ice Sheet Dynamics : Error control and efficiency

   Author : Josefin Ahlkrona; Per Lötstedt; Jesse Johnson; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; ice sheet modelling; stokes equations; shallow ice approximation; finite element method; perturbation expansions; non-newtonian fluids; free surface flow; Scientific Computing; Beräkningsvetenskap;

   Abstract : Ice sheets, such as the Greenland Ice Sheet or Antarctic Ice Sheet, have a fundamental impact on landscape formation, the global climate system, and on sea level rise. The slow, creeping flow of ice can be represented by a non-linear version of the Stokes equations, which treat ice as a non-Newtonian, viscous fluid. READ MORE

4. 2. On the Mean Square Error of Transfer Function Estimates with Applications to Control

   Author : Svante Gunnarsson; Linköpings universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Mean square error; Transfer function; Estimation; Applications;

   Abstract : In this report we study the mean square error of transfer function estimates obtained by identification. The model quality is related to the use of models in regulator design, and the properties of affecting the bias part of the mean square error, both in fixed parameter control and adaptive control. READ MORE

5. 3. Pontryagin approximations for optimal design

   Author : Jesper Carlsson; Anders Szepessy; KTH; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Topology Optimization; Inverse Problems; Hamilton-Jacobi; Regularization; Error Estimates; Impedance Tomography; Numerical analysis; Numerisk analys;

   Abstract : This thesis concerns the approximation of optimally controlled partial differential equations for applications in optimal design and reconstruction. Such optimal control problems are often ill-posed and need to be regularized to obtain good approximations. READ MORE

6. 4. Numerical Model Reduction and Error Control for Computational Homogenization of Transient Problems

   Author : Fredrik Ekre; Chalmers tekniska högskola; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; model reduction; error estimation; computational homogenization;

   Abstract : Multiscale modeling is a class of methods useful for numerical simulation of mechanics, in particular, when the microstructure of a material is of importance. The main advantage is the ability to capture the overall response, and, at the same time, account for processes and structures on the underlying fine scales. READ MORE

7. 5. Adaptive Finite Element Methods for Compressible Two-Phase Flow

   Author : Erik Burman; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; adaptive finite element methods; two-phase flow; compressible flow; conservation laws; hyperbolic systems; a posteriori error estimates; streamline diffusion; stability analysis; quantitative error control; adaptive algorithms; quantitative error control;

   Abstract : In this thesis we develop, apply and analyse adaptive finite element methods with error control for compressible flow problems, focusing in particular on two-phase flow. The adaptive algorithms, aiming at quantitative error control with efficient use of computational resources, are based on a posteriori error estimates, where the error is estimated in terms of the computed solution, the local mesh-size and certain stability factors. READ MORE