• 한국정밀공학회지
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• 제21권4호
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• pp.140-147
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• 2004

In reverse engineering, the whole surfaces of the three-dimensional product are measured using 3D positional scanners. The raw triangle meshes constructed from a scanned point set are not well fitted for direct use in the downstream engineering or graphic activities. No object can be fully described by a single scan. Although multiple scans are usually taken and aligned to achieve a complete model, a set of scanned points does not entirely wrap the whole object. This is because some surfaces may be inaccessible to the scanner, so some portion of the scanned surface may be missing. This paper discusses the algorithms of a hole-filling that are crucial to refine the triangle meshes. In this paper, the holes are filled with flat triangles first by subdivision operation and then smoothed with neighboring triangles. This process continues until it converges to a certain user-defined iteration number. Examples are given and discussed to validate the system.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2001년도 춘계학술대회 논문집
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• pp.41-44
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• 2001

In reverse engineering, the whole surfaces of the three-dimensional(3D) product are measured using 3D positional scanners. The raw triangle meshes constructed from a scanned point set are not well suited for direct use in the downstream activities. This is because the amount of triangle meshes may be very large(from millions to hundreds of millions) and usually distorted by scanning error. Furthermore, the triangle meshes may contain several holes that must be filled. Thus, several solutions have to be addressed and implemented before a complete CAD models can be acquired. This paper discusses on the algorithms of decimation, smoothing, and hole-filling that are crucial to refine the triangle meshes. Several examples are also given and discussed to validate the system.

• 한국지반신소재학회논문집
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• 제18권4호
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• pp.25-37
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• 2019

대표적인 지하 공동 복구공법인 개착 공법은 공사비 및 시공시간의 문제를 드러내고 있으며, 이를 해결하기 위한 다양한 비 개착식 공법이 제시되고 있다. 팽창재료를 이용한 지하 공동 복구공법은 비 개착식 공법 중 하나로 공법의 원리는 다음과 같다. 아스팔트층에 천공된 구멍을 통해 양질의 되메움토와 팽창재료를 공동 내로 투입하면, 투입된 팽창재료에 의해 주변 되메움토가 아직 채워지지 않은 빈 공간으로 밀려남과 동시에 다져지면서 공동을 복구하는 원리이다. 본 연구에서는 공동을 모사한 아크릴 토조에 팽창재료를 이용한 지하공동 복구공법을 시공하였다. 공동의 복구효율은 팽창재료의 투입 위치와 개수에 따른 공동의 채움율과 상대 다짐도로 분석하였으며, 실험결과 공동의 복구효율과 최적 시공 위치는 무관한 것으로 확인되었다.

• 한국CDE학회논문집
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• 제22권1호
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• pp.59-69
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• 2017

Internal capacity of a refrigerator is an important indicator for design and purchasing criteria. The components facing the internal space may have holes or gaps between parts. In traditional way, design engineers manually remodeled the parts to fill the holes and the gaps for enclosed boundary of the internal space. Then they calculated internal volume by subtracting the assembly of parts from its enclosing volume. However, filling holes and gaps is not an automated process requiring a plenty of labor and time. In this research, we have developed a voxel-based method to estimate the internal volume of a refrigerator automatically. It starts transforming all components facing the interior space into voxels and fills all holes and gaps automatically by the developed hole-filling algorithm to form a completely closed boundary of the assembly. Then, it identifies the boundary voxels that are facing to the internal voxels with any part of the component. After getting the intersection points between the boundary voxels and the surfaces of components, it generates the boundary surface of triangular facets with the intersection points. Finally, it estimates the internal volume by adding volume of each tetrahedron composed of a triangle of boundary surface and an arbitrary point.