• Title/Summary/Keyword: 공간해석

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Aseismic design concept for underground space based on site response analysis (부지응답해석에 기초한 지하공간 내진설계 개념)

  • Park, Inn-Joon;Yoo, Ji-Hyeung
    • Journal of Korean Tunnelling and Underground Space Association
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    • v.12 no.3
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    • pp.257-264
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    • 2010
  • This study proposed the aseismic design concept for underground space based on site response analysis and laboratory tests. The results of this study showed that the location of the control points of input motions such as design response spectra and time history of acceleration and the assumption of bedrock properties such as elasticity or rigidity play an important role in aseismic design of underground space. Therefore, the appropriate ground response model among models applying motions such as free surface motion, bedrock motion, or bedrock outcropping motion must be utilized to provide reasonable boundary conditions of underground space under earthquake loading and practical aseismic design.

Spatial Join based on the Transform-Space View (변환공간 뷰를 기반으로한 공간 조인)

  • 이민재;한욱신;황규영
    • Journal of KIISE:Databases
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    • v.30 no.5
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    • pp.438-450
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    • 2003
  • Spatial joins find pairs of objects that overlap with each other. In spatial joins using indexes, original-space indexes such as the R-tree are widely used. An original-space index is the one that indexes objects as represented in the original space. Since original-space indexes deal with sizes of objects, it is difficult to develop a formal algorithm without relying on heuristics. On the other hand, transform-space indexes, which transform objects in the original space into points in the transform space and index them, deal only with points but no sites. Thus, spatial join algorithms using these indexes are relatively simple and can be formally developed. However, the disadvantage of transform-space join algorithms is that they cannot be applied to original-space indexes such as the R-tree containing original-space objects. In this paper, we present a novel mechanism for achieving the best of these two types of algorithms. Specifically, we propose a new notion of the transform-space view and present the transform-space view join algorithm(TSVJ). A transform-space view is a virtual transform-space index based on an original-space index. It allows us to interpret on-the-fly a pre-built original-space index as a transform-space index without incurring any overhead and without actually modifying the structure of the original-space index or changing object representation. The experimental result shows that, compared to existing spatial join algorithms that use R-trees in the original space, the TSVJ improves the number of disk accesses by up to 43.1% The most important contribution of this paper is to show that we can use original-space indexes, such as the R-tree, in the transform space by interpreting them through the notion of the transform-space view. We believe that this new notion provides a framework for developing various new spatial query processing algorithms in the transform space.

Parallel Finite Element Analysis System Based on Domain Decomposition Method Bridges (영역분할법에 기반을 둔 병렬 유한요소해석 시스템)

  • Lee, Joon-Seong;Shioya, Ryuji;Lee, Eun-Chul;Lee, Yang-Chang
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.22 no.1
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    • pp.35-44
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    • 2009
  • This paper describes an application of domain decomposition method for parallel finite element analysis which is required to large scale 3D structural analysis. A parallel finite element method system which adopts a domain decomposition method is developed. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay triangulation method is introduced as a basic tool for element generation. Domain decomposition method using automatic mesh generation system holds great benefits for 3D analyses. Aa parallel numerical algorithm for the finite element analyses, domain decomposition method was combined with an iterative solver, i.e. the conjugate gradient(CG) method where a whole analysis domain is fictitiously divided into a number of subdomains without overlapping. Practical performance of the present system are demonstrated through several examples.