• Journal of the Korean Society for Precision Engineering
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• v.21 no.3
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• pp.91-99
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• 2004

An unstructured tetrahedral mesh generation algorithm has been presented. In order to construct better meshes in interior region by using an advancing front technique, a connecting operator and a local finishing operator II have been developed in addition to the existing operators. Before applying digging operators that generate new nodes inside of a meshing region, a connecting operator is employed that uses existing nodes which satisfy certain conditions for producing well-conditioned elements. The local finishing operator II is introduced to terminate the meshing process more flexibly on remaining subregions. With these new operators, tetrahedral meshing process becomes more robust and good quality of meshes are constructed.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1605-1608
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• 2003

A unstructured tetrahedral mesh generation algorithm has been presented. To make better meshes in interior region using an advancing front technique, a connecting operator has been developed in addition to the existing operators. Before applying digging operators that generate new nodes inside of a meshing region, a connecting operator is employed that uses existing nodes which satisfy certain conditions for producing well-conditioned elements if possible. By introducing this new operator, tetrahedral meshing process becomes more robust and produces better quality of meshes.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.20 no.2
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• pp.553-563
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• 1996

An algorithm for automatic mesh generation of two-dimensional arbitrary planar domain is proposed by using Delaunay triangulation algorithm. An efficient algorithm is proposed for the construction of Delaunay triangulation algorithm over convex planar domain. From the definition of boundary, boundary nodes are first defined and then interior nodes are generated ensuring the Delaunay property. These interior nodes and the boundary nodes are then linked up together to produce a valid triangular mesh for any finite element analysis. Through the various example, it is found that high-quality triangular element meshes are obtained by Delaunay algorithm, showing the robustness of the current method. The proposed mesh generation scheme has been extended to automatic remeshing, which is applicable to FE analysis including large deformation and large distortion of elements.

• Journal of the korean Society of Automotive Engineers
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• v.18 no.4
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• pp.67-87
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• 1996

본 연구에서는 차체의 충돌해석 및 모델링을 위하여 판/쉘 요소의 자동생성 모듈을 개발하고 재료의 변형특성 모델링 모듈 및 접촉처리 모듈을 개발하였다. 충돌해석용 전처리기능으로는 평면, 실린더 곡면, B-스플라인 곡면 및 블렌딩 (blending) 곡면상에서의 사각형 요소망 자동생성 기법과 프로그램을 개발하였다. 또한 차체를 구성하고 있는 여러가지 재료들의 변형거동을 모델링하여 개발중인 충돌해석전용프로그램인 Autocrash의 모듈로서 완성하였다. 이들은 변형률속도의 영향이 고려된 탄소성 재료, 강체 재료, 포옴 재료 및 이방성 재료등으로 정면충돌 해석 및 측면충돌 해석에 필요하다. 한편 접촉처리 모듈에서 접촉탐색법으로는 주종탐색법과 HITA 알고리즘을 병행하여 사용할 수 있도록 프로그래밍하였으며, 불침투 조건의 처리는 벌칙함 수법을 이용하였다.

• Journal of the Korean Society for Precision Engineering
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• v.10 no.3
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• pp.87-96
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• 1993

In this study, the peak stress of a fuillet in elastic structure was optimized to have minimum value by using quadratic isoparametric element. The method of auomatic gridding was also developed along with shape algorithm and design element technique was adopted in selecting design variables. The computer program developed was combined with the Hooke-Jeeves direct algorithm of optimization techniques in order to minimize the peak stress of the fillet. The imployment of design element technique significantly cut down computer time by the reduction in design variables, and the opitmum fillet shape with uniform minimum stress was obtained by varying design variables along x and y directions in improving the shape compared to other results. By using automatic gridding, in which Bezier surfaces and Coons surfaces of cubic interpolation were employed, the irregular boundary was removed resulting in smoother anbd more accurate fillet shape possessing uniform minimum stress.

• Journal of the Korean Society for Precision Engineering
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• v.15 no.12
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• pp.236-243
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• 1998

퍼지 이론과 계산기하학적 수법에 의한 자동요소 생성법, 해석코드 및 상용 솔리드 모델러를 유기적으로 통합한 자동화된 설계시스템을 개발하였다. 본 시스템은 여러 가지 복합현상과 관련된 실제 구조물에 대한 설계기능을 갖고 있다. 정전장 해석, 변형해석 및 모드해석 등과 같은 해석하고자 하는 물리적인 현상에 의존한 형상모델이 자동적으로 유한요소모델로 변환되어 해석을 수행한다. 또한 신경망의 기능을 도입, 통합시킴으로써 설계해의 영역을 유용하게 제시하여 준다. 개발한 시스템은 정전 마이크로머쉰의 성능 평가에 적용하여 그 효용성을 검증하였다.

• Korean Journal of Computational Design and Engineering
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• v.8 no.1
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• pp.41-47
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• 2003

In this paper, a tetrahedral mesh generation algorithm which uses a grid based method for interior region and an advancing front method for outer surface region is proposed. In order to apply an advancing front method for outer region of an object, a new operator so called a hole operator has been developed to handle multiple shells. With this grid based approach in the interior region, more stable and uniform meshes can be constructed especially in the interior region.

• Transactions of the Korean Society of Mechanical Engineers
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• v.18 no.11
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• pp.2932-2943
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• 1994

An efficient approach to the automatic construction of effective quadrilateral finite element meshes for two-dimensional analysis is presented. The procedure is composed of, firstly, an initial mesh generation and, secondly, an h-version of adaptive refinement based on error analysis. As for an initial mesh generation scheme, a modified looping algorithm has been employed. For the adaptive refinement process, an error indicator obtained by computing the residual error of the equilibrium equations in the energy norm with a relaxation factor has been employed. Examples of mesh generation and self-adaptive mesh improvements are given. These example solutions demonstrate that an effective mesh for a given error tolerance can be obtained in a few steps of the analysis processes.

• Proceedings of the Korea Information Processing Society Conference
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• 2001.04a
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• pp.51-54
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• 2001

오늘날 국내외에 인터넷 보급의 대중화가 점차 확대되고 네트워크을 이용하는 게임의 증가에 따라 게임에 관련된 웹 문서에 대한 사용자의 요구가 증가되고 있다. 기존의 수작업에 의한 색인 방식은 많은 전문인력, 시간, 경비등을 필요로 하기 때문에, 기하급수적으로 증가하는 웹 상의 정보를 처리하기에는 이미 그 한계에 이른 실정이다. 이러한 문제점의 해결을 위해 컴퓨터를 이용한 자동색인 시스템의 개발은 매우 중요하고 시급하다. 더구나 게임 분야에서 있어 신조어는 너무나 급속히 생성되고 있다. 따라서 이러한 신조어 처리는 효과적인 자동색인을 위한 중요한 요소이다. 이 논문에서는 사용자들에게 보다 적합하고 안정적인 게임 정보를 제공하기 위해 게임 용어 사전을 이용한 자동색인과 신조어 처리 시스템을 설계, 구현한다. 자동색인 및 신조어 처리를 위해 게임용어사전, TF-IDF, n-gram 추출법을 이용한다.

• Journal of the Korean Society for Marine Environment & Energy
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• v.16 no.2
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• pp.130-137
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• 2013

The more accurate numerical analysis is needed, The more important to arrange nodes and elements properly on the structures wanted to be analyzed. In this study, automatic mesh generation method is developed for triangular mesh modeling in wind tower and substructure formed in circular sections especially, which have structural and economical benefits in shallow water area. It can consider variety conditions by inputting the detail data such as height and types. Also, this study includes the comparison and verification with the mesh generation by Delaunay triangular technique on 3 dimensional space and the examples of mesh generation for proposed tower and substructure. The result of this study will be widely applied to analyze the existing and proposed models for wind turbines.