• Title/Summary/Keyword: 요소분할

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A Study on the improvement of element division of hydrid integral method for analyzing of the offshore structures (해양구조물의 동요해석을 위한 Hybrid적분방정식법의 요소분할 개선에 관한 연구)

  • Lee, Sang-Yeob
    • Journal of the Korean Society of Industry Convergence
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    • v.2 no.2
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    • pp.3-10
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    • 1999
  • Recently, It is proceeding the project of offshore structures in the many contury. A hybrid boundary-integral method is developed for computing wave forces on floating bodies. In this method, using the cylindric boundary for deviding elements, it is convenient to analysis but is difficult to apply to the rectangular or slender bodies. Thus, in this paper, I propose the new method by using the fictitious vertical cylinder of arbitary cross-section and shows results of the numerical analysis for testing.

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Automatic Mesh Generation System for a Novel FEM Modeling Based on Fuzzy Theory (퍼지이론을 이용한 FEM 모델링을 위한 자동 요소분할 시스템)

  • Lee Yang-Chang;Lee Joon-Seong;Choi Yoon-Jong;Kim Nam-Yong
    • Journal of the Korean Institute of Intelligent Systems
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    • v.15 no.3
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    • pp.343-348
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    • 2005
  • This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial solid modelers is employed for three-dimensional solid structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well controlled by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional solid structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

Automatic Mesh Generation System for a Novel FEM Modeling Based on Fuzzy Theory (퍼지이론을 이용한 FEM 모델링을 위한 자동 요소분할 시스템)

  • Lee Joon-Seong;Lee Yang-Chang;Choi Yoon-Jong
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 2005.04a
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    • pp.139-142
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    • 2005
  • This paper describes an automatic finite element (FE) mesh generation for three-dimensional structures consisting of free-form surfaces. This mesh generation process consists of three subprocesses: (a) definition of geometric model, i.e. analysis model, (b) generation of nodes, and (c) generation of elements. One of commercial sol id modelers is employed for three-dimensional sol id structures. Node is generated if its distance from existing node points is similar to the node spacing function at the point. The node spacing function is well control led by the fuzzy knowledge processing. The Delaunay method is introduced as a basic tool for element generation. Automatic generation of FE meshes for three-dimensional sol id structures holds great benefits for analyses. Practical performances of the present system are demonstrated through several mesh generations for three-dimensional complex geometry.

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Development of GUI-type Simulation Software for AHP Decision Support System (다 단계 의사결정지원시스템을 위한 웹기반의 시뮬레이션소프트웨어 개발)

  • 황흥석;조규성;최철훈
    • Proceedings of the Korea Society for Simulation Conference
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    • 2001.05a
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    • pp.8-13
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    • 2001
  • 다 단계 의사결정지원시스템, AHP(Analytic Hierarchy Process)는 다수 대안에 대하여 다 면적인 평가기준과 다수 주체에 의한 의사결정을 위해 설계된 의사결정지원방법의 하나이다. AHP 시스템은 먼저 주어진 시스템을 구성하고있는 요소를 세분하고 그 분할된 요소를 계층적으로 구성하며 다음으로 계층간 각 레벨에 있는 요소의 상대적 중요도에 대한 판단을 종합하는 과정을 거친다. 본 연구에서는 이러한 AHP방법을 실용화하기 위하여 사용자가 Web기반에서 활용하기 쉽도록 GUI-tyre 프로그램을 개발하고 이를 검증하였으며 예제를 들어 보였다. 본 연구에서 개발한 소프트웨어는 크게 다음과 같이 3 가지 구조로 구성하였다. 단계 1 : 대안 평가의 아이디어 창출 단계(Brainstorming), 단계 2 : 다 단계, 다 기준 의사결정지원시스템(AHP), 단계 3 우선 순위 종합모델(MRM)

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A Study on the Numerical Technique for the Nonlinear Deformation Analysis of Solid Structures(2) -Application to a Simple Solid Structure- (고체구조물의 비선형변형 수치해석에 대한 이론적고찰(2) -단순구조물에의 적용-)

  • Youngjoo Kwon
    • Journal of the Korean Society for Precision Engineering
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    • v.15 no.11
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    • pp.166-171
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    • 1998
  • 본 논문에서는 고체구조물의 비선형변형해석에 대하여 일반이론으로 개발된 수치해법을 단순 고체 구조물인 일차원 봉 문제에 적용하여 그 변형해석을 수행 하였다. 정확한 해를 구하기 위하여 증분 뉴톤-랩슨방법이 수정 보완 사용되었다. 또한 개발된 비선형유한요소법의 검증을 위하여 수학적인 정해가 존재하는 균일한 체력이 작용하는 단순봉의 변형을 해석하여 그 결과를 수학적인 정해와 비교하였다. 비교 결과 본 논문을 통하여 개발된 비선형 유한요소법의 정확성이 입증되었다.

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Integrated 3D Skin Color Model for Robust Skin Color Detection of Various Races (강건한 다인종 얼굴 검출을 위한 통합 3D 피부색 모델)

  • Park, Gyeong-Mi;Kim, Young-Bong
    • The Journal of the Korea Contents Association
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    • v.9 no.5
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    • pp.1-12
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    • 2009
  • The correct detection of skin color is an important preliminary process in fields of face detection and human motion analysis. It is generally performed by three steps: transforming the pixel color to a non-RGB color space, dropping the illuminance component of skin color, and classifying the pixels by the skin color distribution model. Skin detection depends on by various factors such as color space, presence of the illumination, skin modeling method. In this paper we propose a 3d skin color model that can segment pixels with several ethnic skin color from images with various illumination condition and complicated backgrounds. This proposed skin color model are formed with each components(Y, Cb, Cr) which transform pixel color to YCbCr color space. In order to segment the skin color of several ethnic groups together, we first create the skin color model of each ethnic group, and then merge the skin color model using its skin color probability. Further, proposed model makes several steps of skin color areas that can help to classify proper skin color areas using small training data.

A Note on Hamilton's Principle for a Free-Surface Flow Problem (자유표면파 문제에서의 하밀톤 원리의 적용에 대한 소고)

  • J.W.,Kim;K.J.,Bai
    • Bulletin of the Society of Naval Architects of Korea
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    • v.27 no.3
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    • pp.19-30
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    • 1990
  • This note describes an application of Hamiton's principle to nonlinear free-surface flow problems. Two functionals are constructed based on classical Hamilton's principle with a modification due to the presence of a free surface. As an effort towards the development of an efficient numerical scheme for our problem, we present the following three test results: i) The bounding principles of the eigenvalues for the linear dispersion relation. ii) By assuming steady solitary waves, an approximate relation between the amplitudes and the speeds of solitary waves are derived from the two functionals constructed. Their numerical results are compared with those of Longuet-Higgins & Fenton(1974). iii) The shapes and charicteristics of solitary waves are computed from two sets of functionals by varying the number of total finite elements in the fluid domain.

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Application of geophysical exploration for gold in the YongJang mine, Masan (마산 용장광산에서 금광에 대한 물리탐사의 적용)

  • Park, Jong-Oh;Song, Moo-Young;Park, Chung-Hwa;You, Young-June
    • 한국지구물리탐사학회:학술대회논문집
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    • 2006.06a
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    • pp.213-219
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    • 2006
  • The Yongjang mine is located in Masan City, Gyeongsangnamdo, which consists of a black shale possessing quartzite veins with othercompositions such as gold, silver, and sublimated sulfur. The average width of the veins is $9{\sim}17cm$ and the average degrees of the gold and silver are 3.6 g/t and 113.6 g/t respectively. A regional and a detailed scale electrical resistivity surveys are conducted to determine the existence of the mineralization zones and the linear structures in the study area. In addition, surveys of a several different array methods are conducted such as dipole-dipole array in the surface and borehole-to-surface array, surface-to-borehole array, and dipole-dipole array in the borehole. The method of element division can be applied to the region in which the borehole is curved, inclined or the distance between the electrodes is shorter than that of nodal points, because the coordinate of each electrode cannot be assigned directly to the nodal point if several electrodes are in an element. Yongjang vein is extended longer under the subsurface than on the surface in the images reconstructed from the 3D inversion. Therefore, it is recognized that the 3-D interpretation of the electrical resistivity survey is a very useful method to figure out the existence of strike and extension direction because the mineralization zones and the linear structures are shown in each depth.

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Synthesis method of elemental images from Kinect images for space 3D image (공간 3D 영상디스플레이를 위한 Kinect 영상의 요소 영상 변환방법)

  • Ryu, Tae-Kyung;Hong, Seok-Min;Kim, Kyoung-Won;Lee, Byung-Gook
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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    • 2012.05a
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    • pp.162-163
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    • 2012
  • In this paper, we propose a synthesis method of elemental images from Kinect images for 3D integral imaging display. Since RGB images and depth image obtained from Kinect are not able to display 3D images in integral imaging system, we need transform the elemental images in integral imaging display. To do so, we synthesize the elemental images based on the geometric optics mapping from the depth plane images obtained from RGB image and depth image. To show the usefulness of the proposed system, we carry out the preliminary experiments using the two person object and present the experimental results.

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The Study of Finite Element Method for Analyses of Travelling Magnetic Field Problem (운동자계 문제의 해석을 위한 유한요소법에 관한 연구)

  • Chang Ho-Sung
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.19 no.4
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    • pp.108-116
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    • 2005
  • This paper presents finite element analyses solution in the travelling magnetic field problem. The travelling magnetic field problem is subject to convective-diffusion equation. Therefore, the solution derived from Galerkin-FEM with linear interpolation function may oscillate between the adjacent nodes. A simple model with Dirichlet, Neumann and Periodic boundary condition respectively, have been analyzed to investigate stabilities of solutions. It is concluded that the solution of Galerkin-FEM may oscillate according to boundary condition and element type, but that of Upwind-FFM is stable regardless boundary condition.