• Journal of the Computational Structural Engineering Institute of Korea
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• v.22 no.5
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• pp.487-499
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• 2009

The postprocessing technology has been advanced diversely to accommodate the tendency of increasingly refined and complicated practices of finite element modeling in pace with enhanced capabilities of computers and improved algorithm of equation solvers. As a result of such progresses in both hardware and software, it became practically meaningful to inspect and analyze the elasto-plastic behavior using the intermediate results from the increasing number of incremental and iterative processes. This paper is concerned about the new methods of postprocessing with computer graphic visualization of elasto-plastic behavior on the basis of the theoretically reorganized analysis results. This paper proposes a new method of rendering the plastic zone, and new approaches of analyzing and interpreting the elasto-plastic behavior using the graphical information visualized in the form of the yield surface and the stress path, or in the form of the Mohr circles and the failure envelope.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.9 no.6
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• pp.735-745
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• 1998

The method of moments has been widely used in the analysis of TM scattering problems. Recently, significant advances in the development of fast and efficient techniques for solving large problems have been reported. In such methods, iterative matrix solvers are preferred by virtue of their speed and low memory requirements. But for near resonant and strong multiple scattering problems, e.g., involving an aircraft engine inlet, a large number of iterations is required for convergence. In this paper, an efficient approximate inverse based preconditioner is used to reduce this number of iterations. By using the matrix partitioning method, the computational is used to reduce this number of iterations. By using the matrix partitioning method, the computational cost for obtaining the approximate inverse is reduced to O(N). We apply this preconditioner to an O(NlogN) algorithm, the multilevel fast multipole algorithm, for the aircraft engine inlet problem. The numerical results show the efficiency of this preconditioner.