## Abstract The report is a retrospective study of 157 patients with pilonidal disease. The period in hospital, the healing time, and the rates of wound breakdown and sinus recurrence were documented following four different methods of management. After incision and drainage of the pilonidal absces
An assessment of some preconditioning techniques in shell problems
✍ Scribed by Benzi, Michele ;Kouhia, Reijo ;Tůma, Miroslav
- Publisher
- John Wiley and Sons
- Year
- 1998
- Tongue
- English
- Weight
- 165 KB
- Volume
- 14
- Category
- Article
- ISSN
- 1069-8299
No coin nor oath required. For personal study only.
✦ Synopsis
Preconditioned Krylov subspace methods have proved to be ecient in solving large, sparse linear systems in many areas of scienti®c computing. The success of these methods in many cases is due to the existence of good preconditioning techniques. In problems of structural mechanics, like the analysis of heat transfer and deformation of solid bodies, iterative solution of the linear equation system can result in a signi®cant reduction of computing time. Also many preconditioning techniques can be applied to these problems, thus facilitating the choice of an optimal preconditioning on the particular computer architecture available.
However, in the analysis of thin shells the situation is not so transparent. It is well known that the stiness matrices generated by the FE discretization of thin shells are very ill-conditioned. Thus, many preconditioning techniques fail to converge or they converge too slowly to be competitive with direct solvers. In this study, the performance of some general preconditioning techniques on shell problems is examined.
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