• Title/Summary/Keyword: Delaunay

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Development of Delaunay Triangulation Algorithm Using Subdivision (분할 Delaunay 삼각화 알고리즘 개발)

  • 박시형;이성수
    • Korean Journal of Computational Design and Engineering
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    • v.7 no.4
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    • pp.248-253
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    • 2002
  • Delaunay triangulation is well balanced in the sense that the triangles tend toward equiangularity. And so, Delaunay triangulation hasn't some slivers triangle. It's commonly used in various field of CAD applications, such as reverse engineering, shape reconstruction, solid modeling and volume rendering. For Example, In this paper, an improved Delaunay triangulation is proposed in 2-dimensions. The suggested algorithm subdivides a uniform grids into sub-quad grids, and so efficient where points are nonuniform distribution. To get the mate from quad-subdivision algorithm, the area where triangulation-patch will be most likely created should be searched first.

Automatic Mesh Generation by Delaunay Triangulation and Its Application to Remeshing (Delaunay 삼각화기법을 이용한 유한요소망의 자동생성과 격자재구성에의 응용)

  • Jeong, Hyeon-Seok;Kim, Yong-Hwan
    • 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.

Modified Delaunay Triangulation Based on Data Structure of Geometric Modeller (형상 모델러의 자료구조에 의한 수정 Delaunay 삼각화)

  • Chae E.-M.;Sah J.-Y.
    • Journal of computational fluids engineering
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    • v.2 no.2
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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).

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Application of Delaunay Triangulation on RP (Delaunay삼각형 분할법의 RP에의 응용)

  • 명태식;채희창;김옥현
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.8 no.3
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    • pp.35-41
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    • 1999
  • STL which is used in Rapid Prototyping is composed of a lot of triangular facets. The number of triangles and the shapes of these triangles determine the quality of STL. Therefore, proper algorithm is necessary to enhance the quality of triangular patch. In this paper we used the Delaunay triangulation method to apply to following processes. 1) On processing for reducing sharp triangles which cause errors on intersection. 2) On processing for connecting two or more collinear edges. 3) On processing for deleting unnecessarily inserted points in coplanar polygon.

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Development of Delaunay triangulation algorithm using quad subdivision (Quad-Subdivision을 이용한 Delaunay 삼각화 알고리즘 개발)

  • 박시형;이성수
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2000.10a
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    • pp.151-156
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    • 2000
  • Delaunay triangulation is well balanced in the sense that the triangles tend toward equiangularity. And so, Delaunay triangulation hasn't some slivers triangle. It's commonly used in various field of CAD applications, such as shape reconstruction, solid modeling and volume rendering. In this paper, an improved Delaunay triangulation is proposed in 2-dimensions. The suggested algorithm subdivides a uniform grids into sub-quad grids, and so efficient where points are non-uniform distribution. To get the mate from quad-subdivision algorithm, the area where triangulation-patch will be most likely created should be searched first.

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Acceleration of Delaunay Refinement Algorithm by Geometric Hashing (기하학적 해싱을 이용한 딜러니 개선 알고리듬의 가속화)

  • Kim, Donguk
    • Korean Journal of Computational Design and Engineering
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    • v.22 no.2
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    • pp.110-117
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    • 2017
  • Delaunay refinement algorithm is a classical method to generate quality triangular meshes when point cloud and/or constrained edges are given in two- or three-dimensional space. It computes the Delaunay triangulation for given points and edges to obtain an initial solution, and update the triangulation by inserting steiner points one by one to get an improved quality triangulation. This process repeats until it satisfies given quality criteria. The efficiency of the algorithm depends on the criteria and point insertion method. In this paper, we propose a method to accelerate the Delaunay refinement algorithm by applying geometric hashing technique called bucketing when inserting a new steiner point so that it can localize necessary computation. We have tested the proposed method with a few types of data sets, and the experimental result shows strong linear time behavior.

Adaptive Element-free Galerkin Procedures by Delaunay Triangulation (Delaunay 삼각화를 이용한 적응적 Element-free Galerkin 해석)

  • 이계희;정흥진;최창근
    • Journal of the Computational Structural Engineering Institute of Korea
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    • v.14 no.4
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    • pp.525-535
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    • 2001
  • In this paper, a new adaptive analysis scheme for element-free Galerkin method(EFGM) is proposed. The novel point of this scheme is that the triangular cell structure based on the Delaunay triangulation is used in the numerical integration and the node adding/removing process. In adaptive analysis with this scheme, there is no need to divide the integration cell and the memory cell structure. For the adaptive analysis of crack propagation, the reconstruction of cell structure by adding and removing the nodes on integration cells based the estimated error should be carried out at every iteration step by the Delaunay triangulation technique. This feature provides more convenient user interface that is closer to the real mesh-free nature of EFGM. The analysis error is obtained basically by calculating the difference between the values of the projected stresses and the original EFG stresses. To evaluate the performance of proposed adaptive procedure, the crack propagation behavior is investigated for several examples.

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Euclidean Steiner Minimum Tree with Delaunay Triangulation for Efficient Construction of Multimedia Communication Network (멀티미디어 통신네트워크의 효율적 구축을 위한 Delaunay 삼각망 적용 유클리드 스타이너 트리)

  • Kim, In-Bum
    • Proceedings of the Korea Multimedia Society Conference
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    • 2012.05a
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    • pp.417-418
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    • 2012
  • 최소 신장 트리를 이용하여 멀티미디어 통신을 위한 네트워크를 구축하는 것보다 효과적인 유클리드 스타이너 트리 생성과정에서 필연적으로 발생되는 막대한 계산 량과 실행시간 문제를 해결하기 위해 Delaunay 삼각망을 적용하는 방법을 제안한다.

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A STUDY OF THE APPLICATION OF DELAUNAY GRID GENERATION ON GPU USING CUDA LIBRARY (GPU Library CUDA를 이용한 효율적인 Delaunay 격자 생성에 관한 연구)

  • Song, J.H.;Kang, S.H.;Kim, G.M.;Kim, B.S.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.194-198
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    • 2011
  • In this study, an efficient algorithm for Delaunay triangulation of a number of points which can be used on a GPU-based parallel computation is studied The developed algorithm is programmed using CUDA library. and the program takes full advantage of parallel computation which are concurrently performed on each of the threads on GPU. The results of partitioned triangulation collected from the GPU computation requires proper stitching between neighboring partitions and calculation of connectivities among triangular cells on CPU In this study, the effect of number of threads on the efficiency and total duration for Delaunay grid generation is studied. And it is also shown that GPU computing using CUDA for Delaunay grid generation is feasible and it saves total time required for the triangulation of the large number points compared to the sequential CPU-based triangulation programs.

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Delaunay Triangulation based Fingerprint Matching Algorithm using Quality Estimation and Minutiae Classification (화질 추정과 특징점 분류를 이용한 Delaunay 삼각화 기반의 지문 정합 알고리즘)

  • Sung, Young-Jin;Kim, Gyeong-Hwan
    • Journal of Korea Multimedia Society
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    • v.13 no.4
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    • pp.547-559
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    • 2010
  • Delaunay triangulation is suitable for fingerprint matching because of its robustness to rotation and translation. However, missing and spurious minutiae degrade the performance and computational efficiency. In this paper, we propose a method of combining local quality assessment and 4-category minutiae classification to improve accuracy and decrease computational complexity in matching process. Experimental results suggest that removing low quality areas from matching candidate areas and classifying minutiae improve computational efficiency without degrading performance. The results proved that the proposed algorithm outperforms the matching algorithm (BOZORTH3) provided by NIST.