Sökning: "model adaptivity"
Visar resultat 1 - 5 av 41 avhandlingar innehållade orden model adaptivity.
1. Model Adaptivity in Elasticity
Sammanfattning : 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. LÄS MER
2. Automation of Computational Mathematical Modeling
Sammanfattning : 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. LÄS MER
3. Valuing Path-Dependent Options using the Finite Element Method, Duality Techniques, and Model Reduction
Sammanfattning : 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. LÄS MER
4. Postprocessing Techniques and Adaptivity in the Finite Element Method
Sammanfattning : 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. LÄS MER
5. Eigenfrequency Analysis FE-Adaptivity and a Nonlinear Eigenproblem Algorithm
Sammanfattning : 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. LÄS MER