• 한국전산유체공학회지
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• 제2권2호
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• pp.97-103
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• 1997

A modified Delaunay triangulation technique is tested for complicated computational domain. While a simple geometry. both in topology and geometry, has been well discretized into triangular elements, a complex geometry having difficulty in triangulation had to be divided into small sub-domains of simpler shape. The present study presents a modified Delaunay triangulation method based on the data structure of geometric modeller. This approach greatly enhances the reliability of triangulation, especially in complicated computational domain. We have shown that efficiency of Delaunay triangulation can be much improved by using both the GUI (Graphic User Interface) and OOP (Object-Oriented Programming).

• 대한기계학회논문집
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• 제13권1호
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• pp.59-66
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• 1989

본 연구는 이상에서 언급된 경향과 3차원 형상모델링 시스템 개발의 필요성에 따라 1차적으로 직육면체, 원기둥, 삼각기둥을 원형(primitive)으로 하는 모델러를 개발하여 CAD/CAM 시스템 개발의 기초자료를 제공함과 동시에 궁극적으로는 국내중소기업에서의 간단한 설계, 제작 생산분야에 알맞는 PC 수준의 전용 3차원 형상모델링 시스템을 개발할 목적으로 수행되었다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1988년도 한국자동제어학술회의논문집(국내학술편); 한국전력공사연수원, 서울; 21-22 Oct. 1988
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• pp.562-566
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• 1988

The purpose of this study is to develop a personal computer aided 3-D geometric modeller. To perform this study, we set up a cube, a cylinder, and a prism as a primitive in the first segment of this study. By modelling the 3-D object through their transformation, addition, and subtraction, we proved the validity of the developed algorithm and its computer program. Some examples show the results of applying the program to modelling a few simple shape of the machine parts. These results met the first aim of this study.

• KIEAE Journal
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• 제16권1호
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• pp.89-94
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• 2016

This study is part of three-dimensional(3D) heat transfer analysis program developmental process. The program is being developed without it's own built in 3D-modeller. So 3D-model must be created from another 3D-modeller such as generic CAD programs and imported to the developed program. After that, according to the 3D-geometric data form imported model, 3D-mesh created for numerical calculation. But the 3D-model created from another 3D-modeller is likely to have errors in it's geometric data such as mismatch of position between vertexes or surfaces. these errors make it difficult to create 3D-mesh for calculation. These errors are must be detected and cured in the pre-process before creating 3D-mesh. So, in this study four kinds of filters and functions are developed and tested. Firstly, 'vertex error filter' is developed for detecting and curing for position data errors between vertexes. Secondly, 'normal vector error filter' is developed for errors of surface's normal vector in 3D-model. Thirdly, 'intersection filter' is developed for extracting and creating intersection surface between adjacent objects. fourthly, 'polygon-line filter' is developed for indicating outlines of object in 3D-model. the developed filters and functions were tested on several shapes of 3D-models. and confirmed applicability. these developed filters and functions will be applied to the developed program and tested and modified continuously for less errors and more accuracy.

• 한국CDE학회논문집
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• 제5권2호
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• pp.184-195
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• 2000

MDO (Multidisciplinary Design Optimization) methodology is an emerging new technology to solve a complicate structural analysis and design problem with a large number of design variables and constraints. In this paper MDO methodology is adopted through the use of computer aided systems such as Geometric Solid Modeller, Mesh Generator, CAD system and CAE system. And this paper introduces MDO methodology as a new method for structural analysis and design through the application to the structural design of flap drive system. In a MDO methodology application to the structural design of flap drive system, kinetodynamic analysis is done using a simple aerodynamic analysis model for the air flow over the flap surface instead of difficult aerodynamic analysis. Simultaneously the structural static analysis is done to obtain the optimum structural condition. And the structural buckling analysis for push pull rod is also done to confirm the optimum structural condition (optimum cross section shape of push pull rod).

• 대한조선학회논문집
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• 제31권4호
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• pp.23-31
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• 1994

구획배치 모델은 구획의 경계면으로 사용되는 구조 부재요소들에 의해 정의되는 공간들의 특성 및 형상정보에 의해 표현된다. 이러한 구획배치 모델링 작업을 효율적으로 수행하기 위해 Chopping 및 Merging 모델링 기법을 이용한 그래픽 지원 대화식 구획배치 모델러를 개발하였다. 일반적으로 구획배치 모델링을 위해 사용되는 프로그램 내부 기법이 아무리 우수해도, 프로그램을 이용하는 사용자 입장에서 입력방식이 불편할 경우에는 프로그램 활용가치는 반감된다. 따라서 본 논문에서는 그래픽 사용자 인터페이스 기법을 이용하여 사용자가 편리하게 구획배치 모델링 작업을 수행할 수 있는 방법을 개발하고 이를 구현하였다. 본 연구를 통해 개발된 구획배치 모델링 방법은 솔리드 모델링 개념의 모델링 기법과 모델링을 위해 사용자가 입력해야 하는 정보를 그래픽 지원 인터페이스를 이용하여 신속하고 편리하게 처리할 수 있도록 함으로써, 효율적인 구획배치 모델링을 수행할 수 있도록 하였다. 본 연구를 통해 개발된 구획배치 모델러를 실선에 적용해 본 결과 보다 효율적이고 편리하게 구획배치 모델링을 수행할 수 있음을 확인하였으며, 실선에 적용한 예를 보였다.