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| Author(s): |
João Luis Gonçalves
Total Authors: 1
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| Document type: | Doctoral Thesis |
| Press: | Campinas, SP. |
| Institution: | Universidade Estadual de Campinas (UNICAMP). Instituto de Matemática, Estatística e Computação Científica |
| Defense date: | 2011-09-30 |
| Examining board members: |
Sonia Maria Gomes;
Eduardo Cardoso de Abreu;
Marcelo Martins dos Santos;
Abimael Fernando Dourado Loula;
Paulo Rafael Bosing
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| Advisor: | Sonia Maria Gomes; Philippe Remy Bernard Devloo; Igor Mozolevski |
| Abstract | |
In this work we study goal-oriented a posteriori error indicators for approximations by the discontinuous Galerkin method for the biharmonic and Poisson equations. The methodology used for the indicators is based on the dual problem associated with the functional, which is known to generate the most effective indicators. The two main error indicators based on the dual problem, obtained for second order problems, are extended to fourth order problems. We also propose a third indicator for second and fourth order problems. The characteristics of the different indicators are studied for the localization of the elements with the greatest contributions of the error, and for the characterization of the regularity of the solutions, as well as their consequences on indicators efficiency. We propose an hp-adaptive strategy specific for goal-oriented error indicators. The performed numerical experiments show that the hp-adaptive strategy works properly, and that the use of hp-adapted approximation spaces turns out to be efficient to reduce the error with a lower number of degrees of freedom. Moreover, in the examples studied, a comparison of the quality of results for the different indicators shows that it may depend on the type of singularity and of the equation treated, showing the importance of having a wider range of indicators (AU) | |