• Title/Summary/Keyword: Triangulation

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A Study on the Static Target Accurate Size Estimation Algorithm with Triangulation (삼각측량법 기반의 정지 표적 정밀 크기 추정기법 연구)

  • Jung, Yun Sik;Kim, Jin Hwan
    • Journal of Institute of Control, Robotics and Systems
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    • v.21 no.10
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    • pp.917-923
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    • 2015
  • In this paper, the TSE (Triangulation based target Size Estimator) algorithm is presented to estimate static target size at IIR (Imaging Infrared) environment. The size information is important factor for accurate IIR target tracking. But the IIR sensor can't generate distance between missile and target to calculate target size. In order to overcome the problem, we propose TSE algorithm which based on triangulation measurement. The performance of proposed method is tested at target intercept scenario. The experiment results show that the proposed algorithm has suitable performance for the accurate static target size estimating.

CONVERTING BITMAP IMAGES INTO SCALABLE VECTOR GRAPHICS

  • Zhou, Hailing;Zheng, Jianmin;Seah, Hock Soon
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2009.01a
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    • pp.435-440
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    • 2009
  • The scalable vector graphics (SVG) standard has allowed the complex bitmap images to be represented by vector based graphics and provided some advantages over the raster based graphics in applications, for example, where scalability is required. This paper presents an algorithmto convert bitmap images into SVG format. The algorithm is an integration of pixel-level triangulation, data dependent triangulation, a new image mesh simplification algorithm, and a polygonization process. Both triangulation techniques enable the image quality (especially the edge features) to be preserved well in the reconstructed image and the simplification and polygonization procedures reduce the size of the SVG file. Experiments confirm the effectiveness of the proposed algorithm.

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Adaptive finite elements by Delaunay triangulation for fracture analysis of cracks

  • Dechaumphai, Pramote;Phongthanapanich, Sutthisak;Bhandhubanyong, Paritud
    • Structural Engineering and Mechanics
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    • v.15 no.5
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    • pp.563-578
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    • 2003
  • Delaunay triangulation is combined with an adaptive finite element method for analysis of two-dimensional crack propagation problems. The content includes detailed descriptions of the proposed procedure which consists of the Delaunay triangulation algorithm and an adaptive remeshing technique. The adaptive remeshing technique generates small elements around the crack tips and large elements in the other regions. Three examples for predicting the stress intensity factors of a center cracked plate, a compact tension specimen, a single edge cracked plate under mixed-mode loading, and an example for simulating crack growth behavior in a single edge cracked plate with holes, are used to evaluate the effectiveness of the procedure. These examples demonstrate that the proposed procedure can improve solution accuracy as well as reduce total number of unknowns and computational time.

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.

Nonparametric logistic regression based on sparse triangulation over a compact domain

  • Seoyeon Kim;Kwan-Young Bak
    • Communications for Statistical Applications and Methods
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    • v.31 no.5
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    • pp.557-569
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    • 2024
  • Based on the investigation of logistic regression models utilizing sparse triangulation within a compact domain in ℝ2, this study addresses the limited research extending the triogram model to logistic regression. A primary challenge arises from the potential instability induced by a large number of vertices, hindering the effective modeling of complex relationships. To mitigate this challenge, we propose introducing sparsity to boundary vertices of the triangulation based on the Ramer-Douglas-Peucker algorithm and employing the K-means algorithm for adaptive vertex initialization. A second order coordinate-wise descent algorithm is adopted to implement the proposed method. Validation of the proposed algorithm's stability and performance assessment are conducted using synthetic and handwritten digit data (LeCun et al., 1989). Results demonstrate the advantages of our method over existing methodologies, particularly when dealing with non-rectangular data domains.

A Study on the application of planning national index numbers in the Cadastral triangulation point (지적삼각(보조)점의 국가지점번호 활용방안에 관한 연구)

  • Lee, Hyong-Sam;Shin, Soon-Ho;Sung, Yeon-Dong
    • Journal of Cadastre & Land InformatiX
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    • v.45 no.2
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    • pp.45-56
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    • 2015
  • The main purpose of this investigation is to make up for the limitations of parcel addressing and to seek the application plan of cadastral triangulation point to effective installation of national index numbers. The test-bed has been constructed at the mountainous area located in Nowon-gu, seven cadastral triangulation points within the test-bed was directly applied to this investigation. Each points have been firstly converted from a plane rectangular coordinates to a single plane rectangular coordinates (UTM-K). To verify positioning results achieved from these points, a single plane rectangular coordinates through the Network-RTK was considered. With regards to verification result, maximum coordinate shift was revealed by 6 cm, this level of difference can be satisfied to Article 7, paragraph 2 "the regulation for National Index Number". This means that coordinate transformation applied with cadastral triangulation points can achieve the sastisfied result without local surveying. And also, remarkable effects have been created in terms of financial effectiveness and safe preservation of cadastral triangulation points due to the omission of local surveying.

A Multiple Branching Algorithm of Contour Triangulation by Cascading Double Branching Method (이중분기 확장을 통한 등치선 삼각화의 다중분기 알고리즘)

  • Choi, Young-Kyu
    • Journal of KIISE:Computer Systems and Theory
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    • v.27 no.2
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    • pp.123-134
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    • 2000
  • This paper addresses a new triangulation method for constructing surface model from a set of wire-frame contours. The most important problem of contour triangulation is the branching problem, and we provide a new solution for the double branching problem, which occurs frequently in real data. The multiple branching problem is treated as a set of double branchings and an algorithm based on contour merging is developed. Our double branching algorithm is based on partitioning of root contour by Toussiant's polygon triangulation algorithml[14]. Our double branching algorithm produces quite natural surface model even if the branch contours are very complicate in shape. We treat the multiple branching problem as a problem of coarse section sampling in z-direction, and provide a new multiple branching algorithm which iteratively merge a pair of branch contours using imaginary interpolating contours. Our method is a natural and systematic solution for the general branching problem of contour triangulation. The result shows that our method works well even though there are many complicated branches in the object.

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A Study on Error Reduction of Indoor Location Determination using triangulation Method and Least Square Method (삼각측량법과 최소자승법을 활용한 실내 위치 결정의 산포 감소 방안에 관한 연구)

  • Jang, Jung-Hwan;Lee, Doo-Yong;Zhang, Jing-Lun;Jho, Yong-Chul;Lee, Chang-Ho
    • Journal of the Korea Safety Management & Science
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    • v.14 no.1
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    • pp.217-224
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    • 2012
  • Location-Based Services(LBS) is a service that provide location information by using communication network or satellite signal. In order to provide LBS precisely and efficiently, we studied how we can reduce the error on location determination of objects such people and things. We focus on using the least square method and triangulation positioning method to improves the accuracy of the existing location determination method. Above two methods is useful if the distance between the AP and the tags can be find. Though there are a variety of ways to find the distance between the AP and tags, least squares and triangulation positioning method are wildely used. In this thesis, positioning method is composed of preprocessing and calculation of location coordinate and detail of methodology in each stage is explained. The distance between tag and AP is adjusted in the preprocessing stage then we utilize least square method and triangulation positioning method to calculate tag coordinate. In order to confirm the performance of suggested method, we developed the test program for location determination with Labview2010. According to test result, triangulation positioning method showed up loss error than least square method by 38% and also error reduction was obtained through adjustment process and filtering process. It is necessary to study how to reduce error by using additional filtering method and sensor addition in the future and also how to improve the accuracy of location determination at the boundary location between indoor and outdoor and mobile tag.

Integration of T-Search and Dynamic-Window Concept for Accelerated Searching Speed in Delaunay Triangulation (Delaunay Triangulation의 폴리건 검색속도 개선을 위한 T-Search와 Dynamic-Window 개념의 결합)

  • Kang, Hyun-Joo;Yoon, Sug-Joon;Kong, Ji-Young;Kim, Kang-Soo
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.5
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    • pp.681-687
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    • 2003
  • Terrain surfaces have to be modeled in very detail and wheel-surface contacting geometry must be well defined in order to obtain proper ground-reaction and friction forces fur realistic simulation of off-road vehicles. Delaunay triangulation is one of the most widely used methods in modeling 3-dimensional terrain surfaces, and the T-search is a relevant algorithm for searching resulting triangular polygons. The T-search method searches polygons in a successive order and may not allow real-time computation of off-road vehicle dynamics if the terrain is modeled with many polygons, depending on the computer performance used in the simulation. The dynamic T-search, which is proposed in this paper, combines conventional T-search and the concept of the dynmaic-window search which uses reduced searching windows or sets of triangular surface polygons at each frame by taking advantage of the information regarding dynamic charactereistics of a simulated vehicle. Numerical tests show improvement of searching speeds by about 5% for randomly distributed triangles. For continuous search following a vehicle path, which occurs in actual vehicle simulation, the searching speed becomes 4 times faster.