• Title/Summary/Keyword: Surface representation

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An Integrated System for Computer-Aided Design and Manufacturing of Sculptured Surface (자유곡면 가공을 위한 CAD/CAM 시스템)

  • Kim, K.S.;Choi, Y.H.
    • Journal of Korean Institute of Industrial Engineers
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    • v.17 no.1
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    • pp.37-49
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    • 1991
  • This report describes an integrated approach to sculptured surface design and manufacture, and a software package for it on a multi-axis NC milling machine. The integrated software consists of four parts : (1) surface fitting procedure for generating the characteristic polyhedron from 3 dimensional CMM data, (2) surface description for generating the mathematical representation of sculptured surfaces. (3) tool path generation for approximating the surface representation into a sequence of linear cutter paths, and (4) tool control for generating the corresponding joint variable values. This integrated approach is generally applicable to sculptured surface manufacturing where multi-axis milling machines are necessary to produce smooth three-dimensional surfaces.

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A Study on the 3D Object Representation based WebSD Using X3D (X3D를 이용한 WebSD기반 3D Object 표현에 대한 연구)

  • 이성태;김이선;기우용;이윤배
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.6 no.4
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    • pp.632-638
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    • 2002
  • Extensible 3D(X3D) is a software standard for defining interactive web and broadcast-based 3D content integrated with multimedia. The data size of Web3D representation based on polygon meshes is so large that transferring practical data fast is a hard problem. This paper proposes 3D object structure, a new framework for compact 3D representation with high quality surface shape. By utilizing a free form surface technique, qualified surface are transferred with limited amount of data size and rendered. 3D graphic structure can be regarded ad both polygon meshes and free form surfaces. Therefore, it can be easily integrated to existing Web3D data formats, for example VRML & XML. 3D object structure also enables modeling free form surface shapes intuitively with polygon modeling like operations.

Displacement Mapping for the Precise Representation of Protrusion (정확한 돌출 형상의 표현을 위한 변위매핑)

  • Yoo, Byoung-Hyun;Han, Soon-Hung
    • Journal of KIISE:Computer Systems and Theory
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    • v.33 no.10
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    • pp.777-788
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    • 2006
  • This paper describes a displacement mapping technique which represents protruded shapes on the surface of an object. Previous approaches for image-based displacement mapping can represent only shapes depressed from the polygon surface. The proposed technique can represent shapes protruded from the underlying surface in real-time. Two auxiliary surfaces which are perpendicular to the underlying surface are added along the boundary of the polygon surface, in order to represent the pixels which overflow over the boundary of the polygon surface. The proposed approach can represent accurate silhouette of protruded shape. It can represent not only smooth displacement of protruded shape, but also abrupt displacement such as perpendicular protrusion by means of adding the supplementary texture information to the steep surface of protruded shape. By per-pixel instructions on the programmable GPU this approach can be executed in real-time. It provides an effective solution for the representation of protruded shape such as high-rise buildings on the ground.

SUBMANIFOLDS WITH PARALLEL NORMAL MEAN CURVATURE VECTOR

  • Jitan, Lu
    • Bulletin of the Korean Mathematical Society
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    • v.35 no.3
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    • pp.547-557
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    • 1998
  • In this paper, we study submanifolds in the Euclidean space with parallel normal mean curvature vectorand special quadric representation. Especially we give a complete classification result relative to surfaces satisfying these conditions.

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A Compact and Efficient Polygonal Mesh Representation (간결하고 효율적인 폴리곤 메쉬의 표현 구조)

  • Park S. K.;Lee S. H.
    • Korean Journal of Computational Design and Engineering
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    • v.9 no.4
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    • pp.294-305
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    • 2004
  • Highly detailed geometric models are rapidly becoming commonplace in computer graphics and other applications. These complex models, which is often represented as complex1 triangle meshes, mainly suffer from the vast memory requirement for real-time manipulation of arbitrary geometric shapes without loss of data. Various techniques have been devised to challenge these problems in views of geometric processing, not a representation scheme. This paper proposes the new mesh structure for the compact representation and the efficient handling of the highly complex models. To verify the compactness and the efficiency, the memory requirement of our representation is first investigated and compared with other existing representations. And then we analyze the time complexity of our data structure by the most critical operation, that is, the enumeration of the so-called one-ring neighborhood of a vertex. Finally, we evaluate some elementary modeling functions such as mesh smoothing, simplification, and subdivision, which is to demonstrate the effectiveness and robustness of our mesh structure in the context of the geometric modeling and processing.

Representation of Ship Hull Surface Using B-Spline (B-Spline을 이용한 선체표면의 표현에 관한 연구)

  • B.H.,Yoon;S.W.,Sur;W.D.,Kim;K.W.,Kim
    • Bulletin of the Society of Naval Architects of Korea
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    • v.22 no.3
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    • pp.19-26
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    • 1985
  • This paper deals with the representation and fairing of ship hull using a B-spline surface which is known as a 3-D model in computer aided free-form design. The first part of this paper is devoted to the fundamental concepts of B-spline theory and its geometrical characteristics. In its second part are described the facillities for efficient application, fast rendering of B-spline surface, and intersection of B-spline surfaces. The examples are presented with actual application to a real ship in the last part. And also a new concept of evaluating the surface fairness by the Gaussian curvature isolines is briefly discussed and its examples are presented.

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Shape Optimization of Shell Surfaces Based on Linkage Framework betweenGeometric Modeling and Finite Element Analysis (유한요소해석과 기하학적 모델링의 연동에 기초한 쉘 곡면의 형상 최적 설계)

  • Kim, Hyon-Cheol;Roh, Hee-Yuel;Cho, Maeng-Hyo
    • Proceedings of the KSME Conference
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    • 2003.11a
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    • pp.1328-1333
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    • 2003
  • In the present study, an integrated framework of geometric modeling, analysis, and design optimization is proposed. Geometric modeling is based on B-spline surface representation. Geometrically-exact shell finite element is implemented in analysis module. Control points of the surface are selected as design variables for optimization, which can make the interaction easier between analysis and surface representation. Sequential linear programming(SLP) is adopted for the shape optimization of surfaces. For the computation of shape sensitivities, semi-analytical method is used. The developed integrated framework should serve as a powerful tool for the geometric modeling, analysis, and shape design of surfaces.

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Implicit Surface Representation of Three-Dimensional Face from Kinect Sensor

  • Wibowo, Suryo Adhi;Kim, Eun-Kyeong;Kim, Sungshin
    • Journal of the Korean Institute of Intelligent Systems
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    • v.25 no.4
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    • pp.412-417
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    • 2015
  • Kinect sensor has two output data which are produced from red green blue (RGB) sensor and depth sensor, it is called color image and depth map, respectively. Although this device's prices are cheapest than the other devices for three-dimensional (3D) reconstruction, we need extra work for reconstruct a smooth 3D data and also have semantic meaning. It happened because the depth map, which has been produced from depth sensor usually have a coarse and empty value. Consequently, it can be make artifact and holes on the surface, when we reconstruct it to 3D directly. In this paper, we present a method for solving this problem by using implicit surface representation. The key idea for represent implicit surface is by using radial basis function (RBF) and to avoid the trivial solution that the implicit function is zero everywhere, we need to defined on-surface point and off-surface point. Based on our simulation results using captured face as an input, we can produce smooth 3D face and fill the holes on the 3D face surface, since RBF is good for interpolation and holes filling. Modified anisotropic diffusion is used to produced smoothed surface.

A Study on the Types of Design Problem Solving by Analogical Thinking - Focused on the Analysis of Associated Words and Sketch - (유추적 사고에 의한 디자인 문제해결의 유형 - 연상된 단어와 스케치 분석을 중심으로 -)

  • Choi, Eun-Hee;Choi, Yoon-Ah
    • Korean Institute of Interior Design Journal
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    • v.16 no.2 s.61
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    • pp.63-70
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    • 2007
  • Analogy in problem solving is similarity-based reasoning facilitated by verbal and visual operation. This similarity-based reasoning generally supports initial phase of idea search. Therefore, this study intends to infer the types of problem solving by tracing the analogy use of verbal and visual representation through a experimental research. According to the result of this research, the types of problem solving by analogy are classified into 'evolving', 'divergent', and 'poor conversion' type. Firstly, 'evolving type' is distinguished between 'combination type' associated different contents to develope a new design and 'transformation type' associated similar words and sketches to be continuously revised and developed. In these types usually structural analogy rather than surface analogy is used. Secondly, in 'divergent type' associated words or sketches are individually represented, and among them one design solution is selected. In this type usually surface analogy is used. Thirdly, in 'poor conversion type' interaction between verbal representation and visual representation does not go on smoothly, and the generation of idea is poor. In here surface analogy is mostly used. These findings could form the basis of skill development of idea generation and conversion in design education.

A study of display rule for none face-to-face emotional worker's job satisfaction (기업의 표현규정이 비대면 감정노동자의 직무만족에 미치는 영향에 관한 연구)

  • Yeo, Hyun Jin;Park, Ji Young;Moon, Jae Young
    • Journal of Korean Society for Quality Management
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    • v.44 no.3
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    • pp.649-660
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    • 2016
  • Purpose: The purpose of this study is to find empirical studies the causal relationship among positive defining representation, negative defining representation, surface acting, deep acting, dissatisfaction of job, and intention of job transfer. Methods: The collected data through the survey by customer satisfaction team of "A" company call center. Results: The result of this study is that emotion and behavior norm influence on deep act of expressing both positive impacts of the employees. Conclusion: Feelings of corporate representation norm is psychologically of employees that because it affects even also must facilitate the surface acts and internal acts of employees and job dissatisfaction at the same time due to emotional dissonance and emotional exhaustion and turnover are hidden on the back emotion norms in the contact department, it should be aware of the need to address the emotional problems. Companies need to develop a variety of programs with attention to addressing the emotional difficulties experienced by workers.