• Title/Summary/Keyword: Geometric Modeling

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기하학적 왜곡을 고려한 카메라 모델링 및 보정기법 개발 (Development of camera modeling and calibration technique with geometric distortion)

  • 한성현;이만형;장영희
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1997년도 한국자동제어학술회의논문집; 한국전력공사 서울연수원; 17-18 Oct. 1997
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    • pp.1836-1839
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    • 1997
  • This paper presents machine vision technique with a camera modeling that accounts for major sources of camera distortion, namely, radial, decentering, and thin prism distortion. Radial distortion causes an inward or outward displacement of a given image point from its ideal location. Actual optical systems are subject to various degrees of decentering, that is, the optical centers of lens elements are not strictly collinear. It is our purpose to develop the vision system for the pattern recognition and the automatic test of parts and to apply the line of manufacturing.

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박막두께 예측을 위한 증착 공정 모델링에 관한 연구 (Study on Evaporating Process Modeling for Estimation of Thin-film Thickness Distribution)

  • 이응기;이동은;김숙한
    • 한국반도체및디스플레이장비학회:학술대회논문집
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    • 한국반도체및디스플레이장비학회 2006년도 춘계학술대회
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    • pp.156-159
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    • 2006
  • In order to design an evaporation system, geometric simulation of film thickness distribution profile is required. In this paper, a geometric modeling algorithm is introduced for process simulation of the evaporating process. The physical fact of the evaporating process is modeled mathematically. Based on the developed method, the thickness of the thin-film layer can be successfully controlled.

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3차원 구조물의 유한요소해석 전처리에 관한 연구(기하학적 모델링을 중심으로) (A Study on the Preprocessing for Finite Element Analysis of 3-Dimensional Structures.(With Focus on Geometric Modelling))

  • 이재영;이진휴;한상기
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1990년도 가을 학술발표회 논문집
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    • pp.40-46
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    • 1990
  • This paper introduces a geometric modelling system adopted in a newly developed preprocessor for finite element analysis of three dimensional structures. The formulation is characterized by hierarchical construction of structural model which consists of control points, curves, surfaces and solids. Various surface and solid modeling schemes based on blending functions and boundary representation are systematized for finite element mesh generation. The modeling system is integrated with model synthesis and operations which facilitate modelling of complex structures.

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단일 기준 틀을 사용한 구조 동역학 모델링 비교 연구 (Comparison Study on Structural Dynamic Modelings Employing Single Reference Frame)

  • 김정민;유홍희
    • 대한기계학회논문집A
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    • 제28권12호
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    • pp.1931-1936
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    • 2004
  • In this paper, modeling methods for the structural dynamic analysis employing single reference frame are presented and their modal and transient analysis results are compared. The geometric stiffening effects often occur when structures undergo large overall motion. These effects were considered in several structural previous modeling methods but the role of reference frame has never been scrutinized. In this study, modeling methods employing single reference frame are presented, and their numerical results are compared. The results show that discrepancy between the two modeling methods increases as the eccentricity of the structural system and the magnitude of the large overall motion increase.

비다양체 모델의 옵셋 기능 개발 (Offsetting Operations in Non-manifold Geometric Modeling)

  • 이상헌
    • 한국CDE학회논문집
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    • 제3권1호
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    • pp.1-14
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    • 1998
  • This paper introduces non-manifold offsetting operations, which add or remove a uniform thickness from a given non-manifold model. Since these operations can be applied to not only solids but also wireframe or sheet objects, they are potentially useful for pipeline modeling, sheet metal and plastic part modeling, tolerance analysis, clearance checking, constant-radius rounding and filleting of solids, converting of abstracted models to solids, HC too1 path generation and so on. This paper describes mathematical properties and algorithms for non-manifold offsetting. In this algorithm, a sufficient set of tentative faces are generated first by offsetting all or a subset of the vertices, edges and faces of the non-manifold model. And then they are merged into a model using the Boolean operations. Finally topological entities which are within offset distance are removed. The partially modified offsetting algorithms for wireframes or sheets are also discussed in order to provide more practical offset models.

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대화형 캐릭터 애니메이션 생성과 데이터 관리 도구 (An Interactive Character Animation and Data Management Tool)

  • 이민근;이명원
    • 정보처리학회논문지A
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    • 제8A권1호
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    • pp.63-69
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    • 2001
  • In this paper, we present an interactive 3D character modeling and animation including a data management tool for editing the animation. It includes an animation editor for changing animation sequences according to the modified structure of 3D object in the object structure editor. The animation tool has the feature that it can produce motion data independently of any modeling tool including our modeling tool. Differently from conventional 3D graphics tools that model objects based on geometrically calculated data, our tool models 3D geometric and animation data by approximating to the real object using 2D image interactively. There are some applications that do not need precise representation, but an easier way to obtain an approximated model looking similar to the real object. Our tool is appropriate for such applications. This paper has focused on the data management for enhancing the automatin and convenience when editing a motion or when mapping a motion to the other character.

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단일 기준 틀을 사용한 구조 동역학 모델링 비교 연구 (Comparison Study on Structural Dynamic Modelings Employing Single Reference Frame)

  • 김정민;유홍희
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2004년도 춘계학술대회
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    • pp.834-839
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    • 2004
  • In this paper, modeling methods for the structural dynamic analysis employing single reference frame are presented and their modal and transient analysis results are compared. The geometric stiffening effects often occur when structures undergo large overall motion. These effects were considered in several structural previous modeling methods but the role of reference frame has never been scrutinized. In this study, modeling methods employing single reference frame are presented, and their numerical results are compared. The results show that discrepancy between the two modeling methods increases as the eccentricity of the structural system and the magnitude of the large overall motion increase.

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플라스틱 사출 금형 설계를 위한 CAD시스템의 개발 (An integrated CAD system for mold design in injection molding processes)

  • 이상헌;이건우;고천진
    • 대한기계학회논문집
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    • 제12권6호
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    • pp.1227-1237
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    • 1988
  • 본 연구에서는 Fig.1은 본 시스템이 제품의 형상을 모델링하고 그것으로부터 어떻게 금형을 설계하는 지를 설명해주고 있다. 본 연구의 범위는 Fig.1의 점선에 의해 둘러 싸인 부분이다. 즉 본 시스템의 모델링 기능을 사용하여 생성시킨 최종제 품 형상으로부터 적당한 몰드 베이스와 그에 장착되는 금형판을 설계 생성시키는 작업 이다.수지의 유동 해석과 NC공구 경로의 계산은 개발 중에 있으며 이들과 함께 통 합되면 완전한 CAD/CAM 시스템을 Fig.1에서와 같이 구축할 수 있다.

민코프스키 덧셈 연산에 근거한 기하 도형의 모핑 제어 방법 (Interactive Control of Geometric Shape Morphing based on Minkowski Sum)

  • Lee, J.-H.;Lee, J. Y.;Kim, H.;Kim, H. S.
    • 한국CDE학회논문집
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    • 제7권4호
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    • pp.269-279
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    • 2002
  • Geometric shape morphing is an interesting geometric operation that interpolates two geometric shapes to generate in-betweens. It is well known that Minkowski operations can be used to test and build collision-free motion paths and to modify shapes in digital image processing. In this paper, we present a new geometric modeling technique to control the morphing on geometric shapes based on Minkowski sum. The basic idea develops from the linear interpolation on two geometric shapes where the traditional algebraic sum is replaced by Minkowski sum. We extend this scheme into a Bezier-like control structure with multiple control shapes, which enables the interactive control over the intermediate shapes during the morphing sequence as in the traditional CAGD curve/surface editing. Moreover, we apply the theory of blossoming to our control structure, whereby our control structure becomes even more flexible and general. In this paper, we present mathematical models of control structure, their properties, and computational issues with examples.