• 한국컴퓨터정보학회:학술대회논문집
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• 한국컴퓨터정보학회 2015년도 제52차 하계학술대회논문집 23권2호
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• pp.198-200
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• 2015

건설산업의 전자도면 작성을 위한 CAD분야는 해외 특정 소프트웨어가 시장을 90%이상 점유하여 기술종속으로 인한 CAD 기술의 자립화 문제가 심각하다. 건설산업에서 발생하는 전자도면의 작성을 위한 프로그램 사용은 자유경쟁을 통한 시장의 흐름에 따른 것이나, 공공기관에서 발주하는 건설사업의 전자도면 관리와 재활용을 위해서는 특정 회사의 과다 독점으로 인한 기술종속에 대한 대책이 필요하다. 따라서, 다양한 CAD 시스템에서 작성한 전자도면을 국내표준에 부합하는 도면으로 변환 가능한 모델러의 개발 방안을 제안한다.

• 대한산업공학회지
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• 제18권1호
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• pp.63-80
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• 1992

The concept of rapid prototyping intended for a significant reduction in cost and lead time becomes even more practical with the recent development of various equipments to make the concept concrete. For the purpose of real application of commercially available SLA(stereolithography apparatus), this paper is intended to develop the standard conversion procedure from CAD data to the input data for SLA. While the procedure presented in this paper is based on CAD system "CATIA" and SLA of 3D systems, Inc., which are being used in authors' company DAEWOO Motor Co., Ltd., the basic concept of this paper can be applied to any other CAD systems and machines of using stereolithography process. The algorithm presented in this paper is classified into two stages-node sampling and triangulation. First of all, point data are sampled through the node sampling procedure, and then these are triangulated so that the input data for SLA operation is finally generated. The suggested method is devised in a way to meet the input requirements of SLA and more importantly consume less computation time and generate less number of input data for SLA.

• 한국정밀공학회지
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• 제20권3호
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• pp.105-111
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• 2003

This paper presents an approach to automate process planning of press dies for manufacturing of car bodies. Considering that the press-dies used at the same press operations regardless of the panels they produce or the car models of which they produce panels have similar shapes except for the forming part of the dies, general approaches to recognize manufacturing features from CAD models are not necessary. Therefore, a hybrid approach is proposed combining feature-based design and feature-extraction approaches. The proposed method recognizes features by parsing the parameters extracted from CAD models and finds proper operations by querying the database by the recognized features. An internet-based process planning system is developed to demonstrate the proposed approach and to suggest a new paradigm of process planning system that utilizes an internet access to the CAD system.

• 한국정밀공학회지
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• 제21권5호
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• pp.131-141
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• 2004

In this study a 3-D automatic die design supporting system for a bonnet panel has been developed using Pro/ROGRAM of the widespread CAD software Pro/ENGINEER A standard drawing die was defined in terms of the punch profile, the die face geometry, and the blank sheet size. The strip layout of a trimming die was defined, in addition, in terms of the trimming line and the locations of scrap cutters. Necessary relations for each design step are formulated and rules for bottom-up type 3-D die design were set up for the automatic design of drawing and trimming dies of a bonnet. With the input geometric data of punch profile, die face, and blank sheet, this 3-D design supporting system could complete the basic design process, in case of the bonnet drawing die, in a time 78% shorter than that required by a typical 2-D CAD system. The new design system showed remarkable design efficiency also when it was applied to the case of redesign and modification of the previous standard output for a different car type.

• 한국전자거래학회지
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• 제1권1호
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• pp.117-140
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• 1996

CALS is recognized as a national response to the new chapter of information society. It is essential that the standardization in Korea should be constructed compatible with not only domestic but also international standardization trend. This study aims to propose a proper direction of CALS standardization in Korea, based on the international CALS standardization movement. This paper classifies standard into five types and provides a proper direction and guidance far each standard. As a trend of CALS standard, all ten data files are converted using SGML standard far the interchangeability of data among heterogenous systems. CAD and Graphic data arc also moving toward to the STEP as their standard. In this regard, this paper discusses how to implement SGML and STEP Model. Finally, this paper proposes a method how to construct an EDI system with CALS standard and how to establish a standard authorization institute which will be responsible far the standard authorization. Furthermore, this paper also proposes the CALS Test Network (CTN) as its experimental method.

• 한국CDE학회논문집
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• 제18권1호
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• pp.71-82
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• 2013

To modify product design easily, modern CAD systems adopt the feature-based model as their primary representation. On the other hand, the boundary representation (B-rep) model is used as their secondary representation. IGES and STEP AP203 edition 1 are the representative standard formats for the exchange of CAD files. Unfortunately, both of them only support the B-rep model. As a result, feature data are lost during the CAD file exchange based on these standards. Loss of feature data causes the difficulty of CAD model modification and prevents the transfer of design intent. To resolve this problem, a tool for recognizing design features from a B-rep model and then reconstructing a feature-based model with the recognized features should be developed. As the first part of this research, this paper presents a method for decomposing a B-rep model into simple volumes suitable for design feature recognition. The results of experiments with a prototype system are analyzed. From the analysis, future research issues are suggested.

• 한국멀티미디어학회논문지
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• 제12권3호
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• pp.397-408
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• 2009

영상 학습은 컴퓨터를 이용한 자동 시각 검사에서 매우 중요하고 어려운 문제이다. 최근 생산되는 인쇄회로 기판(PCB : Printed Circuit Board)은 부품의 크기가 작아지고 회로 패턴이 점점 복잡해져서 신제품의 개발 주기가 짧고 다양한 제품들을 검사해야 하는 분야에서 어렵고 복잡한 학습 과정은 큰 문제가 되고 있다. 본 논문은 CAD(Gerber: 거버)파일을 이용하여 PCB 자동 시각 검사의 기준이 되는 참조 영상을 생성하였다. Gerber 파일로 생성된 참조 영상은 결함이 없는 PCB 패턴을 보장한다. 시스템의 구현과 실험을 통하여 Gerber 파일을 이용하여 PCB 자동 시각 검사 시스템의 학습 과정을 손쉽게 할 수 있는 방안을 제시하였다.

• 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.

• Korean Circulation Journal
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• 제52권1호
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• pp.34-46
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• 2022

Percutaneous coronary intervention (PCI) is used to treat obstructive coronary artery disease (CAD). The role of PCI is well defined in acute coronary syndrome, but that for stable CAD remains debatable. Although PCI generally relieves angina in patients with stable CAD, it may not change its prognosis. The extent and severity of CAD are major determinants of prognosis, and complete revascularization (CR) of all ischemia-causing lesions might improve outcomes. Several studies have shown better outcomes with CR than with incomplete revascularization, emphasizing the importance of functional angioplasty. However, different definitions of inducible myocardial ischemia have been used across studies, making their comparison difficult. Various diagnostic tools have been used to estimate the presence, extent, and severity of inducible myocardial ischemia. However, to date, there are no agreed reference standards of inducible myocardial ischemia. The hallmarks of inducible myocardial ischemia such as electrocardiographic changes and regional wall motion abnormalities may be more clinically relevant as the reference standard to define ischemia-causing lesions. In this review, we summarize studies regarding myocardial ischemia, PCI guidance, and possible explanations for similar findings across studies. Also, we provide some insights into the ideal definition of inducible myocardial ischemia and highlight the appropriate PCI strategy.

• 정보처리학회논문지A
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• 제18A권3호
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• pp.81-92
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• 2011

제품수명주기(Product life cycle) 중 설계단계에서 생성되는 3차원 CAD 데이터를 다양한 단계에서 활용하고자하는 노력이 관련 산업 분야에서 이루어져 왔다. 그러나 3차원 CAD 데이터는 데이터 처리를 위한 많은 컴퓨팅 자원을 요구하고 설계지식이 유출될 수 있는 위험이 있으며, 라이선스 비용이 따르기 때문에 원격지 협업 검토나 마케팅, 전자 기술 매뉴얼과 같은 서비스단계에서 활용하기에 적합하지 않다. 이러한 문제점들을 해결하기 위해 경량화된 가시화 파일형식과 이를 적용한 응용시스템에 대한 다양한 연구가 수행되었으나, 제안된 경량화 파일형식들은 대부분 기업 혹은 기관의 독자적인 형식으로 서로 간에 공유될 수 없으며, 제품의 형상 정보와 함께 제품구조 정보를 표현하는데 한계점을 보이고 있다. 본 연구에서는 이를 해결하기 위하여 웹 기반 3차원 그래픽 표준인 X3D를 활용하여 제품의 형상 정보뿐만 아니라 구조 정보의 표현이 가능한 X3D 기반 데이터 집합인 prod-X3D(Enhanced X3D Dataset for Web-based Visualization of 3D CAD Product Model)를 정의하고, 3차원 CAD 데이터로부터의 변환 기법을 제안한다.