• The Journal of Engineering Research
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• v.2 no.1
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• pp.23-30
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• 1997

For a effective management and easy tool integration of CAD database, Hierarchy interface System(HIS) was designed and GROCO(Graph Representation fOr Complex Objects) Model was presented in another my paper[10]. Hierarchy Interface System which is composed of two subsystems of a configurator and a converter is designed for the interface between a conventional database management system and CAD tools. In this paper, Version Management System is presented for supporting effective operations of HIS using GROCO model. Version Management System supports efficiently CAD database charaters having a hierarchical structure of composite objects. In Version Management System, A design evolves in discrete states through mutation and derivation for going phases of design giving rise to multiple versions. Operations and rules are provided transition between their different states. and for controlling update propagation and preventing version proliferation. Version Modeling Graph is proposed for dealing with versioning at the instance and type levels.

• Proceedings of the Korea Contents Association Conference
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• 2005.05a
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• pp.401-405
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• 2005

In this paper, we designed data transformation interface for the automation of PCB product. The data designed to CAD does not exchange itself for the assembly line, so we analyzed the information of PCB components designed to CAD and developed human error detect algorithm. We also constructed database for the information of IC components. Developed the algorithm can change to the data suitable for the assembly line of PCB and this system was designed to do addition and revision of the components through the user interface. By automating existing manual processing, we were able to shorten the time of 1-2 days to several minutes and enhance reliability of the data and the efficient assembly line of PCB.

• Journal of the Korean Society of Industry Convergence
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• v.2 no.2
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• pp.41-49
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• 1999

In general, FORTRAN is used for numerical analysis and OPS5 or LISP is used for expert systems, This causes problems at the interface because the various applications require different computing languages or environments. This paper describes the approach used to take AutoCAD as a user-interface for an existing finite element structural analysis package. Some principles concerning database management related to data-exchange interface of pre- and post-processing system for FORTRAN structural analysis program are discussed, and numerical examples demonstrate the power of the combination of these programs.

• Korean Journal of Computational Design and Engineering
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• v.21 no.2
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• pp.186-195
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• 2016

The finite element modeling of a ship for hull structural analysis on the basis of new harmonized common structural rules (CSR-H) is to be extended to the cargo holds in fore and after body of a ship. Unlike the parallel middle-body where the external and internal features of hull are equal along to the longitudinal direction of a ship, in fore and after body, the external and internal features of hull vary linearly or even irregularly in forms of a surface or a curve along to the longitudinal direction of a ship. Thus, it needs lots of design man-hours for the modeling for structural analysis. In order to save man-hours in initial structural design phase of a ship, the specified 3D CAD system has been adopted in shipbuilding industry. Through the interface between CAD and CAE (rule scantling and direct strength assessment), design man-hour in initial design phase can be saved even under the environment of CSR-H.

• The Journal of Korean Academy of Prosthodontics
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• v.54 no.4
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• pp.370-378
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• 2016

Purpose: The purpose of this study was to investigate screw joint stability and sagittal fit between internal connection implant fixtures of two different manufacturers and customized abutments. Materials and methods: Internal connection implant systems from two different manufacturers (Biomet 3i system, Astra Tech system) were selected for this study (n=24 for each implant system, total n=48). For 3i implant system, half of the implants were connected with Ti ready-made abutments and the other half implants were connected with Ti CAD-CAM custom ones of domestic-make (Myplant, Raphabio Co., Seoul, Korea) and were classified into Group 1 and Group 2 respectively. Astra implants were divided into Group 3 and Group 4 in the same way. Micro-CT sagittal imaging was performed for fit analysis of interfaces and preloading reverse torque values (RTV) were measured. Results: In the contact length of fixture-abutment interface, there were no significant differences not only between Group 1 and Group 2 but also between Group 3 and Group 4 (Mann-Whitney test, P>.05). However, Group 2 and Group 4 showed higher contact length significantly than Group 1 and Group 3 in abutment-screw interface as well as fixture-screw one (Mann-Whitney test, P<.05). In addition, RTV was lower in CAD-CAM custom abutments compared to ready-made ones (Student t-test, P<.05). Conclusion: It is considered that domestically manufactured CAD-CAM custom abutments have similar fit at the fixture abutment interface and it could be used clinically. However, RTV of CAD-CAM custom abutments should be improved for the increase of clinical application.

• Journal of Internet Computing and Services
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• v.2 no.4
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• pp.25-32
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• 2001

The CAD tools for ASIC design, which are already developed or will be developed in the future, have their own functions and different working environments in many cases. Therefore, it would be more effective in achieving the final design goal, if we have a system called CAD framework in which these CAD tools are systematically integrated. In this paper, we introduce same novel techniques for integrating systematically such the CAD tools, which are usually developed under UNIX shell environments, into the CAD framework with the standard graphics interface such as X-windows. Some meta languages and script file formats are developed for flexible specification of the system MENU hierarchy and the data dependencies among executable programs. We integrated two existing CAD tools into our CAD framework using the techniques and find out the integrated protype system is working well under the new system environments.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.22 no.1
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• pp.148-159
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• 1998

Spot welding palys a key role in increasing productivity and weight reduction of the final products. This paper proposes a systematic approach on the design of spot weld configuration, dealing with the requried number and location of spot weld joints under the given design parameters, such as the applied loads, lap area, and individual spot weld strength. The optimal design of a spot-welded joint is postulated as a state when the safety factors of all spot weld points (i) are evenly distributed and (ii) reach maximum value. A CAD program is developed to arrange the optimal location of each spot weld based on the derived objective function and constraints. The CAD tool integrates the optimization procedure with Finite Element Analysis (FEA) code through an interface. The interface automatically provides geometrical data and mesh configuration for different spot weld locations to FEA model. It also extracts the transmitted load of each spot weld from the FEA code, and allows the optimization code predict an improved arrangement of spot weld locations. The feasibility of the developed approach is demonstrated by the selected examples.

• Journal of Korean Institute of Industrial Engineers
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• v.18 no.2
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• pp.11-22
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• 1992

Up to now, most researches on production automation have concentrated on local automation, e. g. CAD, CAM, robotics, etc. However, to achieve total automation it is required to link each local modules such as CAD, CAM into a unified and integrated system. One such missing link is between CAD and computer vision system. This thesis is an attempt to link the gap between CAD and computer vision system. In this paper, we propose algorithms that carry out edge detection, thinning and pruning from the image data of manufactured parts, which are obtained from video camera and then transmitted to computer. We also propose a feature extraction and surface determination algorithm which extract informations from the image data. The informations are compatible to IGES CAD data. In addition, we suggest a methodology to reduce search efforts for CAD data bases. The methodology is based on graph submatching algorithm in GEFG(Generalized Edge Face Graph) representation for each part.

• The Journal of Society for e-Business Studies
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• v.3 no.1
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• pp.1-22
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• 1998

SDAI (Standard Data Access Interface) is an interface specification of accessing various storage systems such as file systems and database management systems for STEP data. Using SDAI, both application program developers and CAD/CAM system developers can be relieved from dealing with STEP physical file or system dependent DBMS operations. In this paper, we present implementations of SDAI on different data models, i.e., relational, extended relational, and object-oriented. In order to implement SDAI, we need to translate the EXPRESS information model into target data models. The schema translation process for three different data models are compared and other implementation issues are discussed.

• Archives of design research
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• v.17 no.1
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• pp.241-252
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• 2004

In this time, CAD is most important tool in Product Design Process. Traditional design methods were hardly used in Concurrent Engineering Process. But, CAD tools based on Reverse Engineering method have a lot of serious problem in using designer's works. Especially, in the early stage in design process, adopting CAD tool is impossible, cause of a property of design - intuition. A late studies about CAD system have approaching its quantitative factors in not only software but also hardware. In this paper, I researched about the problems of traditional 3d CAD tools and the new interface approach methods in recent CAD studies. Then, I proposed the guidelines and two alternatives about to developing 3D3T in ubiquitous engineering environment.