제품 정보 교환을 위한 국제 표준 STEP의 모듈화 전략에 대한 연구

李玄燦 弘益大學校 科學技術硏究所 2005 科學技術硏究論文集 Vol.16 No.-

The STEP stands for standard for exchange of product model data. It represents ISO 10303. Recently, new development strategy of modularization has implemented in developing new APs (Application Protocols). In this paper, the concepts of STEP modularization and the impacts of the modularization to various stakeholders of STEP are investigated. In the concepts, the foundation philosophy, historical background, and the emerging issues of the modularization are discussed. The impacts of the modularization are given based on the stakeholders of STEP such as common resource, EXPRESS language, end user, software developer, software vendor, AP developer, etc. Finally, based on the analysis, future direction in these fields in Korea are proposed.

CAD에서의 물체의 기하학적 및 위상학적 요소들의 매개변수화 전략

李玄燦 弘益大學校 科學技術硏究所 1994 科學技術硏究論文集 Vol.5 No.-

Parametric design is a very useful tool for product modeling and modification. In this paper, we propose a 2D parametric design system is based on macro programming in the AutoCAD design system. Using AutoLISP, we define new commands which provide parametric design. User can design a product parametrically using the new commands and the sequence of design is stored in a history file. When design changes are occurred, the history file is used for producing new product model. The 3D parametric design system is based on features. Features are local shapes of a product which are directly related to manufacturing methods. To utilize features in design, features are defined parametrically in the form of primitive instancing and stored in a feature library. A product model is represented by a CSG tree, a binary tree. By evaluating the CSG tree, a product model is produced.

곡률 단조성을 유지하는 Bezier Spiral의 설계

李玄燦,洪錫瑢 弘益大學校 科學技術硏究所 2000 科學技術硏究論文集 Vol.11 No.-

Many spiral segments are useful in the design of fair curves. They can be used in CAD/CAM systems, the design of highway and railway and the design of trajectories of mobile robots. In this paper, we propose a new method to calculate Bezier spirals under the condition that the curvature of the Bezier spirals is absolutely monotone. The main purpose of this paper is to find a unique Bezier spiral that matches given G¹ Hermite data. Using the G¹ Hermite data, Bezier spiral can be calculated with a equation. However, the equation for calculating the Bezier spiral is not derived from the first derivative of curvature of a Bezier curve. Instead, the equation is derived from approximation values of discrete curvatures for the control points of the Bezier curve. Designers can control the degree of Bezier spirals freely with our new Bezier spirals.

제품 정보 국제 표준 STEP에서의 공통 형상 표현 지원 내용 연구

李玄燦 弘益大學校 科學技術硏究所 2004 科學技術硏究論文集 Vol.15 No.-

The STEP stands for standard for exchange of product model data. It represents ISO 10303. In the STEP, common shape representation is supported by various part groups. In this paper, four major part groups are investigated. The first part group is part 40's, the integrated generic resources, which provide the fundamental framework for shape representation. The second part group is part 500's, the AIC (Application Interpreted Constructs), which provide common shape representation for APs (Application Protocol). The third part group is part 50's and 100's, the parametrics, which provide the representation schemes for variational design and history-based parametric design. The fourth part group is the rest of STEP parts which are involved in shape representation such as AP 203. In this paper, these part groups are summarized in terms of common shape representation supports and relationship among these parts are analysed. Finally, based on the analysis, future works in these fields in Korea are proposed.

GIS에서 질의의 결과로 얻은 정보의 그래픽을 이용한 디스플레이 방법에 관한 연구

洪錫瑢,李玄燦 弘益大學校 科學技術硏究所 1996 科學技術硏究論文集 Vol.7 No.2

In this paper, an existing GIS Gothic is investigated to find out how geometric information is handfor efficient display in GIS. For the purpose, first, we study the overall structure of the Gothic system. Then, display-related modules are identi-fied and the relationship among the modules are investigated. In the Gothic system, display modules are organized as frames and the frames are built in C-like language LULL and by calling display-related library functions. Prime display-related libraries are Auto Display Library, Plotting Library, Display Library, and Representation Library. Based on the analysis, we propose an advanced display strategies, which include expansion of the libraries, frames, and task-based functions and effective use of ADE plus, which is a development environment provided by Gothic system.

3차원 곡면의 지역적 순정에 관한 연구

洪錫瑢,李玄燦 弘益大學校 科學基術硏究所 1999 科學技術硏究論文集 Vol.10 No.2

The reverse engineering is commonly used in the product design. For the reverse engineering, existing products are digitized for the computer modeling. Using the digitized data, surfaces are modeled for the new products. However, in the digitizing process, measuring errors or deviations can be happened very often. Therefore, it is very important to handle such measuring errors or deviations during the computer modeling. If the errors are ignored, modeling results can be undesirable. To handle the errors, fairing process is performed. In this paper, we investigate surface fairing based on various fairness metrics. Fairness metrics can be discrete. Discrete metrics are used when a point set is given as an input. In this paper, we adopt discrete metrics for fairing given 3D points. The fairness metrics include curvature. In this paper, automatic fairing process is proposed for fairing given 3D point sets for surfaces. The process uses various fairness criteria so that it is adequate to adopt designers' intents.

제품 정보 국제 표준 STEP에서의 매개변수 설계 방법론 지원 내용 연구

李玄燦,洪忠成 弘益大學校 科學技術硏究所 2003 科學技術硏究論文集 Vol.14 No.-

The STEP stands for standard for exchange of product model data. It represents ISO 10303. In the STEP, parametric design methodology is supported by various parts. The first part is ISO 10303-55: integrated generic resource: procedural and hybrid representation. The second part is 10303-108: integrated application resource: parameterization and constraint for explicit geometric product models. The third part is ISO 10303-NWI: integrated application resource: 2D standard modeling commands for the procedural parametric exchange. And the last part is ISO 10303-111: integrated application resource: construction history features. In this paper, these parts are summarized in terms of parametric design supports and relationship among these parts are analysed.

소수의 불규칙적인 이차원 모양군이 지속적으로 반복되는 경우의 재료절단 알고리즘 개발

이현찬 대한산업공학회 1993 대한산업공학회 춘계학술대회논문집 Vol.1993 No.5

기존의 곡면 분할 알고리듬 비교 연구

李玄燦,朱柄俊,洪忠成 弘益大學校 科學技術硏究所 2001 科學技術硏究論文集 Vol.12 No.-

Recently, designing and visualizing 3D objects become getting more important issues in related industrial fields due to new trends such as Virtual Design using CAD(Computer-Aided Design) systems and high-speeded internet. In this paper, we compare the existing surface subdivision algorithms. Subdivision algorithm is a 3D modeling technique that generates a very smooth surface through many times of refinement processes that split polygons of control mesh into several smaller polygons. We examine the methods of calculating new vertices and topological algorithms of three existing subdivision algorithms, Doo-Sabin, Catmull-Clark, and Loop subdivision scheme in detail, and compare them to find the differences, merits and demerits. In calculating new vertices, Doo-Sabin scheme is simpler than Catmull-Clark and Loop schemes. But in topological algorithm, Catmull-Clark and Loop schemes are simpler than Doo-Sabin scheme.

제4차산업혁명과 로봇기술, 관광산업에의 영향

이현찬,양위주 동북아시아문화학회 2017 동북아시아문화학회 국제학술대회 발표자료집 Vol.2017 No.10

The purpose of this study is to review the effect of the fourth industrial revolution on robotics of tourism industry in China. The related cases were taken and briefly reviewed. The findings suggested that the communication channel between the central government and public sector resulted in the current top leader in the relevant around the world.