• 한국HCI학회:학술대회논문집
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• 한국HCI학회 2006년도 학술대회 1부
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• pp.1107-1112
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• 2006

Geometry PIG (Pipeline Inspection Gauge)는 배관 내에 삽입되어 내부를 흐르는 매체에 의해서 추진되는 장치로서 배관의 기하학적 형상을 파악하기 위해 사용된다. Geometry PIG는 여러 종류의 센서를 지니고 배관 내부를 주행 하면서 탑재된 저장장치에 빠른 샘플링 속도로 데이터를 저장하기 때문에 획득된 많은 양의 데이터를 분석하기 위한 가시화 기법이 필요하다. 본 논문에서는 데이터의 특성을 고려하여 다양한 가시화 기법들의 스키마를 정의하고, 이러한 가시화 기법들을 이용해 geometry PIG 데이터 분석을 위한 통합된 가시화 기법을 제안한다. 통합된 가시화 기법은 각 가시화 기법들을 사용자가 원하는 형태로 배치하며 사용자가 원하는 시점에서 데이터를 파악할 수 있도록 가시화 기법에 따른 동기화와 사용자 인터페이스를 지원한다.

• 한국수학교육학회지시리즈E:수학교육논문집
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• 제19권4호
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• pp.621-631
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• 2005

The purpose of this study is to consider how to restructure the university geometry curriculum and contents in terms of applications to theoretical computer science. We analyzed various topics from computer graphics, CAGD(computer aided geometric design) and computational geometry suitable for geometry students interested in applications. Moreover we discussed about selections of topics for several cases.

• 한국학교수학회논문집
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• 제6권2호
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• pp.39-53
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• 2003

본 연구에서는 인터넷 환경에 적합한 동적기하 소프트웨어에 대하여 논의하였다. 먼저 동적기하 소프트웨어의 필요성을 살펴보고, 상용되고 있는 소프트웨어인 GSP, Cabri, Cinderella의 기능 및 특징을 비교하였다. 그리고 본 연구진에 의하여 국내 최초로 개발된 DRC(Digital Ruler and Compass)의 개발과정과 구조에 대하여 알아보고, 인터넷 환경에서 DRC를 활용한 학습 방안에 대하여 알아보고 이후의 발전전망에 대하여 논의하였다.

• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2002년도 춘계학술대회 논문집
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• pp.637-642
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• 2002

Generally, the use of robots in manufacturing industry has been increased during the past decade. GMA(Gas Metal Are) welding is an actively growing area and many new procedures have been developed for use with high strength alloys. One of the basic requirement for welding applications is to study relationships between process parameters and bead geometry. The objective of this paper is to develop a new approach involving the use of neural network and multiple regression methods in the prediction of bead geometry for GMA welding process and to develop an intelligent system that enables the prediction of bead geometry using Rapid Prototyping(RP) in order to employ the robotic GMA welding processes. This system developed using MATLAB/SIMULINK, could be effectively implemented not only for estimating bead geometry, but also employed to monitor and control the bead geometry in real time.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.546-550
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• 2002

This paper proposes an error compensation method that improves accuracy with geometry information of injection molding parts. Geometric information can give an improved accuracy in reverse engineering. Measuring data can not lead to get accurate geometric model, including errors of physical parts and measuring machines. Measuring data include errors which can be classified into two types. One is molding error in product, the other is measuring error. Measuring error includes optical error of laser scanner, deformation by probe forces of CMM and machine error. It is important to compensate these in reverse engineering. Least square method(LSM) provides the cloud data with a geometry compensation, improving accuracy of geometry. Also, the functional shape of a part and design concept can be reconstructed by error compensation using geometry information.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2002년도 춘계학술대회 논문집
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• pp.608-611
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• 2002

In GMAW(Gas Metal Arc Welding) process, bead geometry (penetration, bead width and height) is a criterion to estimate welding quality. Bead geometry is affected by welding current, arc voltage and travel speed, shielding gas, CTWB (contact- tip to workpiece distance) and so on. In this paper, welding process variables were selected as welding current, arc voltage and travel speed. And bead geometry was reasoned from the chosen welding process variables using negro-fuzzy algorithm. Neural networks was applied to design FL(fuzzy logic). The parameters of input membership functions and those of consequence functions in FL were tuned through the method of learning by backpropagation algorithm. Bead geometry could be reasoned from welding current, arc voltage, travel speed on FL using the results learned by neural networks.

• 한국멀티미디어학회논문지
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• 제13권12호
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• pp.1748-1759
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• 2010

We extend the octree subdivision process from Cartesian coordinates to spherical coordinates to develop more efficient space-partitioning structure for surface models. As an application of the proposed structure, we apply the octree subdivision in spherical coordinates ("S-Octree") to geometry compression in progressive mesh coding. Most previous researches on geometry-driven progressive mesh compression are devoted to improve predictability of geometry information. Unlike this, we focus on the efficient information storage for the space-partitioning structure. By eliminating void space at initial stage and aligning the R axis for the important components in geometry information, the S-Octree improves the efficiency in geometry information coding. Several meshes are tested in the progressive mesh coding based on the S-Octree and the results for performance parameters are presented.

• Journal of Biosystems Engineering
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• 제21권3호
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• pp.343-356
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• 1996

The plot geometry of the paddy land is directly related to the performance of machines, especially those having a large size and high speed. The study was to investigate the optimum plot geometry from the standpoint of mechanization. A simulator, Field-Plot-Structure-Evaluation-System(FPSES) was developed for evaluation of the field performance of machines according to the plot geometry. The efficiency and capacity of different sizes of machinery used for rice farming functions were analyzed for a various combination of plot geometry, which could be used as reference for the land reclamation planning and mechanization programming. It is shown that the plot size of about two hectares having a length of 200m and width of loom may be optimum, considering the efficiency and capacity of large sized machinery available currently and in near future.

• 한국전산유체공학회:학술대회논문집
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• 한국전산유체공학회 2001년도 추계 학술대회논문집
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• pp.152-156
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• 2001

Three dimensional orthogonal grid generation is able to control effectively the grid spacing near the boundaries, but there are some difficulty to meshing complex geometry. The mesh complex geometry by orthogonal grid generation method must divide block of geometry It is required a careful skill, and long time. Its also difficulty to make unstructured mesh on complex geometry. Particularly, three dimensional geometry must have more time and effort. Recently, there have been growing interests in mesh generation of complex grometry, aslike an automobile headlamp, the heart. The method of easily meshing complex geometry is resarched to solve them. We suggest octree grid into one among these methods. As octrce grid is automaticaly adapted at the boundaries by determine the level operations to control the grid spacing near the boundaries are unnecessary. In this paper we showed throe dimensional mesh generation, and heat-flow analysis on the octree mesh.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2007년도 춘계학술대회A
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• pp.1778-1782
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• 2007

Based on three-dimensional (3-D) FE limit analyses, this paper estimates effect of internal pressure on plastic limit loads for elbows with circumferential through-wall crack under in-plane bending incorporating large geometry change effects. Circumferential through-wall crack in extrados is considered. The FE limit analyses using the large geometry change option provide plastic collapse loads (using the twice-elastic-slope method). For the bending mode, closing bending is considered. Other relevant variables affecting plastic limit loads are systematically varied, related to pipe bend geometry (the mean radius, thickness and bend curvature) and defect geometry (the length of circumferential through-wall crack).