• Structural Engineering and Mechanics
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• 제35권2호
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• pp.127-140
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• 2010

This paper focuses on a number of criteria that enable controlling the influence of geometric simplification on the quality of finite element (FE) computations. To perform the mechanical simulation of a component, the corresponding geometric model typically needs to be simplified in accordance with hypotheses adopted regarding the component's mechanical behaviour. The method presented herein serves to compute an a posteriori indicator for the purpose of estimating the significance of each feature removal. This method can be used as part of an adaptive process of geometric simplification. If a shape detail removed during the shape simplification process proves to be influential on mechanical behaviour, the particular detail can then be reinserted into the simplified model, thus making it possible to readapt the initial simulation model. The fields of application for such a method are: static problems involving linear elastic behaviour, and linear thermal problems with stationary conduction.

• 한국주조공학회지
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• 제30권5호
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• pp.196-200
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• 2010

The structural stress and fatigue behavior of tensile specimen containing internal shrinkage defect were modeled. Real shrinkage defect in casting was scanned by industrial CT (computed tomography), and subsequently its shape was simplified by ellipsoidal primitives for the structural analysis (S.S.M., shape simplification method). The analysis results were compared with the results by real shrinkage shape without any simplification process. It was possible to consider real shrinkage of casting in stress analysis and the method to predict fatigue life of casting with defect was proposed.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2009년도 춘계학술발표회 논문집
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• pp.15-17
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• 2009

본 연구에서는 건설 CAD 도면을 수치지도 갱신을 위한 공간데이터로 변환하는데 있어서 선회함수를 활용하여 선형 데이터를 단순화시키는 기법에 대한 연구를 수행하였다. 이 기법은 선형의 형상을 수치적으로 표현하는데 유용한 선회함수 기법을 기반으로 절점 사이의 거리와 각을 정량적으로 평가하여 효율적으로 절점을 제거하는 선형 단순화 기법이다. 적용결과, 높은 형상 보존 효과와 절점 감소율을 보였으며 수치지도 작성내규에 대해 100%의 만족율을 보여 건설도면을 활용하여 수치지도 갱신을 위한 단순화 기법으로 유용하게 사용될 가능성이 높을 것으로 판단된다.

• 한국측량학회:학술대회논문집
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• 한국측량학회 2010년 춘계학술발표회 논문집
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• pp.5-6
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• 2010

Needs for the methodology of segmentation of linear feature according to the shape characteristics of line feature are increasing in cartographic linear generalization. In this study, the line segmentation method using expansible moving window is presented. This method analyzes the generalization effect of line simplification algorithms depend on the line characters of linear feature and extracts the sections which show exclusively low positional error due to a specific algorithm. The description measurements of these segments are calculated and the target line data are segmented based on the measurements. For segmenting the linear feature to a homogeneous section, expansible moving window is applied. This segmentation method is expected to be used in the cartographic map generalization considering the shape characteristics of linear feature.

• International Journal of CAD/CAM
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• 제6권1호
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• pp.73-79
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• 2006

In this paper, we propose a new triangular finite element mesh generation method based on simplification of high-density mesh and adaptive Level-of-Detail (LOD) methods for efficient CAE. In our method, mesh simplification is used to control the mesh properties required for FE mesh, such as the number of triangular elements, element shape quality and size while keeping the specified approximation tolerance. Adaptive LOD methods based on vertex hierarchy according to curvature and region of interest, and global LOD method preserving density distributions are also proposed in order to construct a mesh more appropriate for CAE purpose. These methods enable efficient generation of FE meshes with properties appropriate for analysis purpose from a high-density mesh. Finally, the effectiveness of our approach is shown through evaluations of the FE meshes for practical use.

• 한국의류학회지
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• 제29권9_10호
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• pp.1359-1368
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• 2005

When we develop the tight-fit 2D pattern from the 3D scan data, segmentation of the 3D scan data into several parts is necessary to make a curved surface into a flat plane. In this study, Garland's method of triangle simplification was adopted to reduce the number of data point without distorting the original shape. The Runge-Kutta method was applied to make triangular patch from the 3D surface in a 2D plane. We also explored the detailed arrangement method of small 2D patches to make a tight-fit pattern for a male body. As results, minimum triangle numbers in the simplification process and efficient arrangement methods of many pieces were suggested for the optimal 2D pattern development. Among four arrangement methods, a block method is faster and easier when dealing with the triangle patches of male's upper body. Anchoring neighboring vertices of blocks to make 2D pattern was observed to be a reasonable arrangement method to get even distribution of stress in a 2D plane.

• 한국멀티미디어학회논문지
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• 제16권4호
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• pp.418-429
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• 2013

본 논문은 혼합형 폴리라인 단순화와 공간 에너지 집중을 이용한 GIS 벡터맵 데이터 압축을 제안한다. 제안한 방법에서는 GIS 벡터맵에서 폴리라인 속성을 가지는 레이어들에 대해, 최소 면적 오차 기반의 혼합형 폴리라인 단순화 및 공간 에너지 집중에 의하여 선택된 레이어 내의 폴리라인 데이터들을 압축한다. 제안한 단순화 및 공간 에너지 집중는 폴리라인의 형상을 유지하면서 데이터 압축 효과를 향상시킨다. 가시적 화질과 압축률을 통한 평가 결과로부터 제안한 방법이 기존 방법보다 우수한 화질과 높은 압축률을 보임을 확인하였다.

• 한국디자인학회:학술대회논문집
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• 한국디자인학회 2003년도 봄 학술발표대회논문집
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• pp.100-101
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• 2003

• 한국주조공학회지
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• 제39권1호
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• pp.1-6
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• 2019

During the casting process, it is possible to minimize shrinkage and blowholes by modifying the casting design. However, it is impossible to eliminate these factors completely. Therefore, mechanical design engineers apply a sufficient safety factor owing to the possibility of insufficient performances of the cast products. In this paper, prediction method of the fatigue life of cast products containing shrinkage is conducted by using CT (computed tomography) and the SSM (shape simplification method), and additional fatigue analyses are carried out. The analysis results are then compared to results from actual experiments on samples with shrinkage defects. It is found to be that the considering actual shrinkage in cast products by means of stress and fatigue analyses is more accurate and effective. It is also considered that the proposed hot spot method provides us a good tool to predict the fatigue lifes of cast product.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2003년도 학술회의 논문집 정보 및 제어부문 B
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• pp.445-448
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• 2003

This paper presents a novel iris recognition method using wavelet transform and curve simplification. One-dimensional signals, which are calculated over circles on the iris, are decomposed into a multiple frequency bands. Each decomposed signal is approximated by a piecewise linear curve connecting node points. The curve is simplified by progressively removing unimportant node points while keeping the shape of the curve. Finally, a small number of node points represent features of each signal. Experiment results show that the presented method results in good performance in various noise environments.