• Proceedings of the Korean Society of Precision Engineering Conference
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• 1994.10a
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• pp.689-694
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• 1994

In this paper, to develop a smart CAD/CAM system for systematically performing from the 3-D solid shape design of products to the CNC cutting operation of products by a machining center, a B-Rep solid modeler is realized based on the half edge data structure. Because the B-Rep solid modeler has the various capabilities related to the solid definition functions such as the creation operation of primitives and the translational and rotational sweep operation, the solid manipulation functions such as the split operation and the Boolean set operation, and the solid inversion function for effectively using the data structure, the 3-D solid shape of products can be easily designed and constructed. Also, besides the automatic generation of CNC code, the B-Rep solid modeler can be used as a powerful tool for realizing the automatic generation of finite elements, the interference check between solids, the structural design of machine tools and robots and so on.

• Journal of the Korean earth science society
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• v.38 no.1
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• pp.80-90
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• 2017

To build tetrahedra mesh for FEM numerical analysis, Boundary Representation (B-Rep) model is required, which provides the efficient volume description of an object. In engineering, the parametric solid modeling method is used for building B-Rep model. However, a geological modeling generally adopts discrete modeling based on the triangulated surface, called a Sealed Geological Model, which defines geological domain by using geological interfaces such as horizons, faults, intrusives and modeling boundaries. Discrete B-Rep model is incompatible with mesh generation softwares in engineering because of discrepancies between discrete and parametric technique. In this research we have developed a converting program from Sealed Geological Model to Gmsh and COMSOL software. The developed program can convert complex geological model built by geomodeling software to user-friendly FEM software and it can be applied to geoscience simulation such as geothermal, mechanical rock simulation etc.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.675-680
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• 1993

컴퓨터를 이용한 제품의 설계시 개념설계부터 최종설계에 이르는 동안 설계모델은 많은 수정을 요하게 된다. 이 과정에서 개념설계 단계부터 솔리드 모델을 채용하는 것은 불편하므로, 와이어프레임 모델이나 곡면 모델을 이용하여 설계를 진행하다가, 최종설계 단계에서 솔리드 모델로 전환하는 것이 바람직하다. 이 경우 이 3가지 모델을 모두 지원하는 모델러가 요구되는데 '복합다양체'를 지원하는 모델러가 이 요건을 만족시킨다. 또한 경계표현(B-rep)방식으로 모델링시 불리안 작업자를 많이 이용하는데, 모델링 도중에 불리한 작업으로 생성된 모델의 Undo작업은 용이하지 않은 일이다. 따라서 불리안 작업으로 생성된 모델의 수정작업을 위한 알고리즘이 요구된다, 일한 수정작업을 위해선 복합다양체를 지원하는 자료구조가 필요하다. 본 논문에선 이러한 복합다양체 자료구조를 갖는 형상모델러의 기본적 자료구조와 기본물체 모델링시 오일러 작업자를 구현하였다.

• Korean Journal of Computational Design and Engineering
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• v.2 no.3
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• pp.150-160
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• 1997

Existing non-manifold data structures which use the ordered topological representation method, are designed based on a "Model" which is the highest topological entity. Their non-manifold information is always included in edges and vertices even if they are in the manifold situation. Thus they require large storage spaces than manifold data structures. The proposed data structure reduces its storage space by removing unnecessary information stored in edges and vertices. Topological information is classified into manifold and non-manifold information. The main non-manifold information is radial cycles and disk cycles. The proposed data structure always stores manifold information. For the non-manifold situation, the edge stores radial cycles, and the vertex stores disk cycles. The storage space can be reduced in the later stage of CAD design when the ratio of non-manifold to manifold entities is small.