• Proceedings of the Korean Information Science Society Conference
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• 1998.10b
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• pp.39-41
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• 1998

복잡한 자료 구조와 정교한 연산자를 필요로하는 CAD/CAM, GIS와 같은 응용 분야를 위하여 객체지향 데이터베이스에 대한 많은 연구가 있어왔으며, 이들에 대한 노력으로 객체지향 데이터베이스의 표준으로 널리 확산되고 있는 ODMG 2.0이 발표되었다. 따라서 공간 객체지향 데이터베이스 관리 시스템은 OMEGA(Object Management system for Geospatial Applications)의 응용 프로그래밍 인터페이스로서 ODMG 2.0의 C++ OML을 채택하였다. 본 논문에서는 OMEGA의 C++ OML 클레스들 중 몇 가지 중요한 클래스들의 구조 및 구현 방법에 대하여 기술하며 C++ OML 클래스 구현 시 발생되는 문제점들중 중요한 몇 가지 사항에 대하여 해결 방안을 논의한다.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.24 no.69
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• pp.133-143
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• 2001

가공조건은 가공비용과 시간을 줄이고 제품의 품질을 결정하는데 영향을 주는 주요 요인중의 하나이다. 본 논문에서는 밀링 공정을 위한 작업설계(Operation Planning) 시스템에서, 가공조건을 지속적으로 향상시키기 위한 새로운 방법론을 제안한다. 제안된 방법론은 밀링 작업에 대하여 (1) 퍼지 아트맵 신경회로망 모델에 의해 가공조건을 실시한 학습하고 (2) 교체 알고리즘이라 불리는 새로운 알고리즘을 포함한다. 제안된 교체 알고리즘은 기존의 학습 정보보다 효율적인 새로운 가공조건이 얻어졌을 때 이를 이용하여 기존의 학습 정보보다 효율적인 새로운 가공조건이 얻어졌을 때, 이를 이용하여 기존의 학습 정보를 대체하는 기능을 수행한다. 본 논문에서는 우선 작업설계 시스템의 전반적인 기능을 간략히 소개한 후 제안된 방법론에 의한 의사결정 과정을 자세히 기술한다. 또한, 다양한 시뮬레이션을 통하여 제안된 방법론의 의한 의사결정 과정을 자세히 기술한다. 또한, 다양한 시뮬레이션을 통하여 제안된 방법론의 성능을 예시하도록 한다.

• International Journal of CAD/CAM
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• v.8 no.1
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• pp.55-62
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• 2009

Scene Transition Nets(STN) is a very useful modeling method for discrete-continuous hybrid systems. However, it is difficult to write STN in standard object-oriented programming languages because STN programming requires much skill of object-oriented programming and high knowledge of STN of designers. To overcome this problem, the authors have developed a useful GUI simulator software for modeling and simulations of STN. The experimental results of a transport system including an AGV showed the availability of our software.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.983-988
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• 2004

In the present study, the effects of orthogonal ribs on structural warpage during injection molding process were investigated. Basic ribbed models for the evaluation of degree of warpage were introduced and designed. Injection molds for these models are manufactured based on the full 3D CAD/CAM technology and specimens are prepared for experiment. Numerical analysis using commercial plastic injection molding analysis software was also performed to compare the results with experimental ones. The variations of materials and parameters such as injection time, mold temperature, melt temperature, holding time were considered in the present work. It was shown that orthogonal ribs have significant effect on the reduction of warpage during the injection molding process.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.10a
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• pp.347-352
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• 2002

The Cut off-type progressive die for U-bending production part is a very specific division. This study reveals the sheet metal forming process with multi-forming die by Center Carrier type feeding system. Through the FEM simulation by DEFORM, it was accepted to u-bending process as the first performance to design of strip process layout. The next process of die development was studied according to sequence of die development, i.e. die structure, machining condition for die making, die materials, heat treatment of die components, know-how and so on. The feature of this study is the die development of scrapless progressive die of multi-stage through the Modeling on the I-DEAS program, components drawing on the Auto-Lisp, CAD/CAM application, ordinary machine tool operating and revision by tryout.

• Korean Journal of Computational Design and Engineering
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• v.11 no.5
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• pp.344-350
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• 2006

A method for extracting material information on sheet metal parts from an assembly model is proposed. In order to estimate the cost and order the required sheet metals, their outline profiles, thicknesses, quantities, and etc. are needed. The proposed method consists of two steps: First, sheet metal parts are selected through a feature recognition process from an assembly model. Then, some geometric information for the parts is calculated. In the later step a flattening process of bent parts is included. The method is implemented on a commercial CAD/CAM system Unigraphics with API routines and applied to steam turbine generators and large scale boilers.

• International Journal of CAD/CAM
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• v.7 no.1
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• pp.113-120
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• 2007

Sketch based query plays an important role in shape matching for 3D shape retrieval system. Some researchers suggest the sketch based query interfaces. It is more effective to capture the needs of users rather than query by example. In this paper, we propose a new 2D sketch based query interface with coarse filters for shape matching. Coarse filtering enables to eliminate unfavorable shapes from shapes in DB. For the purpose of coarse filtering, we use two filters with the topological and geometric patterns. For the validity of our method, we show the experimental results.

• Journal of Korean Institute of Industrial Engineers
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• v.21 no.4
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• pp.493-506
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• 1995

Presented in this paper is an algorithm to obtain the intersections of a polyhedral surface composed of triangle facets with a series of parallel planes for extracting machining information from the surface. The change of the topology of the intersection curves is caused by characteristic points of the surface when sectioning the surface with parallel planes. The characteristic points are internal maximum, internal minimum, internal saddle, boundary maximum, boundary minimum, boundary max-saddle, and boundary min-saddle points. The starting points of the intersects are found efficiently and robustly using the characteristic points. The characteristic points as well as the intersection contours can be used to evaluate the machining information for process planning, and to generate NC tool path in CAD/CAM system.

• Journal of Powder Materials
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• v.8 no.1
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• pp.20-25
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• 2001

Most of mold manufacturing procedures have been automated by the introduction of NC machine tool and CAD/CAM system. But the three-dimensional surface curvature of the mold must be done by hand work of well-skilled workers. Magnetic abrasive polishing powders were investigated for surface polishing for 3D curvature. This study aims to investigate homogeneously distributed hard phase in Fe matrix and strong bonding between Fe-matrix and hard phase. The NbC powder, $B_4C$ powder and $Al_2O_3$ powder were mixed in Fe-matrix respectively. Mixed Fe-hard phase powders were compacted by press and then these were melted by plasma melting. According to SEM, XRD and OM observation, Fe-NbC magnetic abrsive powder had the most homogeneous distribution and strong bonding. As a result of magnetic polishing, the surface roughness before magnetic polishing, 1 ${\mu}m$ $R_{max}$, was reduced to 0.2 ${\mu}m$ $R_{max}$ over the entire inner surface of the tube.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.30 no.1
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• pp.24-32
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• 2021

Dental implant have been in use for a long time to restore at missing tooth. But, To place dental implant at good position very is difficult. Improperly positioned dental implants make some problems to have a good function of dental implant. so, To place dental implant at accurate position is the most important step throughout the whole process. Digital guided system of dental implant is very useful to have a accurate position of dental implant and it makes upper restoration more esthetic and funcional.