Search for dissertations about: "model adaptivity"

Showing result 1 - 5 of 41 swedish dissertations containing the words model adaptivity.

2. 1. Model Adaptivity in Elasticity

   Author : David Heintz; Göteborgs universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; finite element method; dimension reduction; a posteriori error; model error; model adaptivity; model error;

   Abstract : We consider model adaptivity in elasticity for dimensionally reduced forms, and shall treat different conceptual approaches. The basic idea, however, is to adaptively refine, not only the computational mesh, but also the underlying mathematical formulation. READ MORE

4. 2. Automation of Computational Mathematical Modeling

   Author : Anders Logg; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; computational mathematical modeling; automation; adaptivity; multi-adaptivity; individual time steps; dual problem; a priori; a posteriori; model reduction; individual time steps;

   Abstract : This thesis concerns the Automation of Computational Mathematical Modeling (CMM), involving the key steps of automation of (i) discretization, (ii) discrete solution, (iii) error control, (iv) modeling, and (v) optimization. The automation of (i)--(ii) is realized through multi-adaptive Galerkin methods on general discretizations of space-time with time steps variable in space. READ MORE

5. 3. Valuing Path-Dependent Options using the Finite Element Method, Duality Techniques, and Model Reduction

   Author : Georgios Foufas; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; finite element method; Galerkin; duality; a posteriori error estimation; adaptivity; option pricing; Greeks; Brownian motion; European option; barrier option; lookback option; Asian option; average option; POD; model reduction; balanced truncation; lookback option;

   Abstract : In this thesis we develop an adaptive finite element method for pricing of several path-dependent options including barrier options, lookback options, and Asian options. The options are priced using the Black-Scholes PDE-model, and the resulting PDE:s are of parabolic type in one spatial dimension with different boundary conditions and jump conditions at monitoring dates. READ MORE

6. 4. Postprocessing Techniques and Adaptivity in the Finite Element Method

   Author : Fethi Abdulwahab; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; error estimation; postprocessing; adaptivity; superconvergence; finite element;

   Abstract : The Finite Element (FE) method is an approximate method and as such the accuracy of its solutions must be controlled to allow for a reliable application. This thesis deals with error estimation and improvements of the FE solutions based on superconvergent properties of the FE solution in certain points. READ MORE

7. 5. Eigenfrequency Analysis FE-Adaptivity and a Nonlinear Eigenproblem Algorithm

   Author : Patrik Hager; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; nonlinear eigenvalue; finite element; adaptivity; superconvergent patch recovery; rational krylov;

   Abstract : Engineering often pose the problem of computing the frequencies with which a system oscillates and the corresponding displacement patterns the system forms, and in case damping is present then the rates of which the amplitudes of the displacement patterns decay are also required. It is necessary to compute these quantities within a prescribed accuracy and the effort required for the computations should be minimised. READ MORE