• Title/Summary/Keyword: Triangulation

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Solving Minimum Weight Triangulation Problem with Genetic Algorithm (유전 알고리즘을 이용한 최소 무게 삼각화 문제 연구)

  • Han, Keun-Hee;Kim, Chan-Soo
    • The KIPS Transactions:PartB
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    • v.15B no.4
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    • pp.341-346
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    • 2008
  • Minimum Weight Triangulation (MWT) problem is an optimization problem searching for the triangulation of a given graph with minimum weight. Like many other graph problems this problem is also known to be NP-hard for general graphs. Several heuristic algorithms have been proposed for this problem including simulated annealing and genetic algorithm. In this paper, we propose a new genetic algorithm called GA-FF and show that the performance of the proposed genetic algorithm outperforms the previous one.

Fingerprint Identification Based on Hierarchical Triangulation

  • Elmouhtadi, Meryam;El Fkihi, Sanaa;Aboutajdine, Driss
    • Journal of Information Processing Systems
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    • v.14 no.2
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    • pp.435-447
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    • 2018
  • Fingerprint-based biometric identification is one of the most interesting automatic systems for identifying individuals. Owing to the poor sensing environment and poor quality of skin, biometrics remains a challenging problem. The main contribution of this paper is to propose a new approach to recognizing a person's fingerprint using the fingerprint's local characteristics. The proposed approach introduces the barycenter notion applied to triangles formed by the Delaunay triangulation once the extraction of minutiae is achieved. This ensures the exact location of similar triangles generated by the Delaunay triangulation in the recognition process. The results of an experiment conducted on a challenging public database (i.e., FVC2004) show significant improvement with regard to fingerprint identification compared to simple Delaunay triangulation, and the obtained results are very encouraging.

The Development of Laser Displacement Sensor using CCD&Optical triangulation technique (CCD 와 Optical triangulation Technique을 이용한 Laser Displacement Sensor 의 개발)

  • 박희재;이동성;유인상;유영기
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2000.11a
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    • pp.47-50
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    • 2000
  • Optical triangulation is one of the most common methods for acquiring range data. Using this method. We have developed a new type of Laser Displacement Sensor. We used Area CCD instead of linear CCD and PSD (Position Sensitive Detector). And we have developed the robust algorithm for increasing the accuracy and used USB instead of RS-232C for increasing speed. We present results that demonstrate the validity of our method using optical triangulation technique, Area CCD, and USB.

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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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Evaluation of Large Scale Digital Mapping by Photogrammetry with GPS/INS (GPS/INS 항측에 의한 대축척 수치지형도 제작의 효율성 평가)

  • Wie, Gwang-Jae;Suh, Young-Woon;Yang, In-Tae;Choi, Yun-Soo;Lee, Ja-Young
    • Journal of Korean Society for Geospatial Information Science
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    • v.16 no.1
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    • pp.43-48
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    • 2008
  • In this study, it was estimated efficiency of GPS/INS photogrammetry by comparison of accuracy and economical efficiency between conventional aerial triangulation and GPS/INS aerial triangulation at the base of large scale digital mapping using GPS/INS aerial survey. The results of aerial triangulation with GPS/INS showed that 40% of working amount was reduced in the process of ground control point survey compared to conventional aerial triangulation. In case of 1/5000 scale aerial triangulation, the results showed that 55% GCP work was reduced in 10 and 20 block size, and 60% GCP work was reduced in 30 block size, under the assumption of keeping the same accuracy.

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Triangulation of Voronoi Faces of Sphere Voronoi Diagram using Delaunay Refinement Algorithm (딜러니 개선 알고리듬을 이용한 삼차원 구의 보로노이 곡면 삼각화)

  • Kim, Donguk
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.41 no.4
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    • pp.123-130
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    • 2018
  • Triangulation is one of the fundamental problems in computational geometry and computer graphics community, and it has huge application areas such as 3D printing, computer-aided engineering, surface reconstruction, surface visualization, and so on. The Delaunay refinement algorithm is a well-known method to generate quality triangular meshes when point cloud and/or constrained edges are given in two- or three-dimensional space. In this paper, we propose a simple but efficient algorithm to triangulate Voronoi surfaces of Voronoi diagram of spheres in 3-dimensional Euclidean space. The proposed algorithm is based on the Ruppert's Delaunay refinement algorithm, and we modified the algorithm to be applied to the triangulation of Voronoi surfaces in two ways. First, a new method to deciding the location of a newly added vertex on the surface in 3-dimensional space is proposed. Second, a new efficient but effective way of estimating approximation error between Voronoi surface and triangulation. Because the proposed algorithm generates a triangular mesh for Voronoi surfaces with guaranteed quality, users can control the level of quality of the resulting triangulation that their application problems require. We have implemented and tested the proposed algorithm for random non-intersecting spheres, and the experimental result shows the proposed algorithm produces quality triangulations on Voronoi surfaces satisfying the quality criterion.

Accuracy Analysis on result of the station of triangulation to secure stable cadastral surveying result -Focusing on Changwon-si, Gyeongsangnam-do- (안정적인 지적측량 성과 확보를 위한 삼각점 성과의 정확도 분석 -경상남도 창원시를 중심으로-)

  • Leem, Hyun-Seok;Hong, Sung-Eon
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.12 no.8
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    • pp.3478-3485
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    • 2011
  • This study utilized the GPS data of the stations of triangulation of Changwon-si, Gyeongsangnam-do to conduct comprehensive analysis on tolerance level and regional characteristics. Based on this analysis, it was attempted to seek the method to derive more accurate result when further performing cadastral control point surveying for cadastral detail surveying. For the stations of triangulation installed at time of the land survey project, the study result showed that the most results of the stations of triangulation are stable if they were not moved naturally or artificially by themselves. Therefore, it was concluded that the stations of triangulation installed at the time of the land survey project should be preemptively selected for use of the given points when making decision of result of cadastral control point surveying. In addition, if the result of the cadastral control point surveying is made decision based on the stations of triangulation presented as the stable result in this study result, it seems that the same surveying result will be maintained and managed at all time, even if they are going to be further reinstalled due to loss of them.

A Study on Self-Localization of Home Wellness Robot Using Collaboration of Trilateration and Triangulation (삼변·삼각 측량 협업을 이용한 홈 웰니스 로봇의 자기위치인식에 관한 연구)

  • Lee, Byoungsu;Kim, Seungwoo
    • Journal of IKEEE
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    • v.18 no.1
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    • pp.57-63
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    • 2014
  • This paper is to technically implement the sensing platform for Home-Wellness Robot. The self-Localization of indoor mobile robot is very important for the sophisticated trajectory control. In this paper, the robot's self-localization algorithm is designed by RF sensor network and fuzzy inference. The robot realizes its self-localization, using RFID sensors, through the collaboration algorithm which uses fuzzy inference for combining the strengths of triangulation and triangulation. For the triangulation self-Localization, RSSI is implemented. TOA method is used for realizing the triangulation self-localization. The final improved position is, through fuzzy inference, made by the fusion algorithm of the resultant coordinates from trilateration and triangulation in real time. In this paper, good performance of the proposed self-localization algorithm is confirmed through the results of a variety of experiments in the base of RFID sensor network and reader system.

An Analysis of the Accuracy of Reference Points in Cadastral Area Using GPS (위성측량을 이용한 지적기준점의 정확도 분석)

  • Kang, In-Joon;Choi, Jong-Bong;Kwak, Jae-Ha;Choi, Hyun
    • Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
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    • v.20 no.1
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    • pp.39-46
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    • 2002
  • This paper shows what is point to be considered at that time in cadastral settlement surveying after declination analysis between GPS and traditional surveying at coordinate result of cadastral triangulation points and supplementary point in site selected deplaning of streets which is surveyed traditional surveying. In the case that coordinates of cadastral triangulation assistance points was decided by standard of the existing cadastral triangulation points that direction of the error vector is in opposition, authors could know all errors was reduced inside coordinate by error being offset each other through the results of study. The coordinates result of cadastral triangulation point by standard of the cadastral triangulation points reduces the deviation value through error that an intersection points was centered being offset each other but through the result that a tendency of errors occurrence is analyzed goniometrys, supplementary points that is close to cadastral triangulation assistance points was affected by error of cadastral triangulation assistance points.

Visualization of Affine Invariant Tetrahedrization (Slice-Based Method for Visualizing the Structure of Tetrahedrization) (어파인 불변성 사면체 분할법의 가시화 (절편 법을 이용한 사면체 구조의 가시화))

  • Lee, Kun
    • The Transactions of the Korea Information Processing Society
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    • v.3 no.7
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    • pp.1894-1905
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    • 1996
  • Delauuany triangulation which is the dual of Dirichlet tessellation is not affine invariant. In other words, the triangulation is dependent upon the choice of the coordinate axes used to represent the vertices. In the same reason, Delahanty tetrahedrization does not have an affine iveariant transformation property. In this paper, we present a new type of tetrahedrization of spacial points sets which is unaffected by translations, scalings, shearings and rotations. An affine invariant tetrahedrization is discussed as a means of affine invariant 2 -D triangulation extended to three-dimensional tetrahedrization. A new associate norm between two points in 3-D space is defined. The visualization of the structure of tetrahedrization can discriminate between Delaunay tetrahedrization and affine invariant tetrahedrization.

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