• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.84-94
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• 2002

• Transactions of the Korean Society of Mechanical Engineers A
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• v.26 no.1
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• pp.48-54
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• 2002

A part definition must not only provide shape information of a nominal part but also contain non-shape information such as tolerances, surface roughness and material specifications. Although machining features are useful for suitable shape information fur process reasoning in CAPP, they need to be integrated with tolerance information for effective process planning. We develop a tolerance modeler that efficiently integrates the machining features with the tolerance information fur feature-based CAPP. It is based on the association of machining features, tolerance features, and tolerances. The tolerance features in this study, where tolerances are assigned, are classified into two types; one type is a face that is a topological entity on a solid model and the other type is a functional geometry that is not referenced to topological entities. The (unctional geometry is represented by using machining features. All the data fur representing the tolerance information are stored completely and unambiguously in an independent tolerance data structure. The developed tolerance modeler is implemented as a module of a comprehensive feature-based CAPP system.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.27 no.10C
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• pp.912-920
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• 2002

As computer systems and communication technologies develop rapidly, CSCW(Computer Supported Collaborative Work) system appears nowadays, through which it is available to work on virtual space without any restriction of time and place. Most of CWCS systems depend on a special network and groupware. The systems of graphics and CAD are not so many because they are specified by hardware and application software. We propose a Web-based collaborative CAD system which is independent from any platforms, and develop a 3D solid modeler in the system. This system can be worked in the environment of Client/Server architecture. Clients connect to the design server through Java applet on WWW. The server is implemented by Java application.

• Journal of KSNVE
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• v.9 no.4
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• pp.703-713
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• 1999

A side mirror is an important safety tool with which the driver can observe objects out of sight. This paper presents an organized design technology for the side mirror of improved vibration characteristics. Resonance response to forced vibration is critical to observability through the mirror to be designed. This study aims at the reduction of vibration level by the modification of mirror structures and consequent effects are predicted by computer simulations. We used a three-dimensional solid modeling and the modal and frequency analysis ; Pro/Engineer is used as a solid modeler; Pro/Mechanica for vibration analysis. The simulation results are compared with those obtained in experiemnts to check the validity by the three-dimensional modeling. The design technique of side mirror has been established and found to be effective in vibration analysis of redesigned parts.

• Proceedings of the Korean Society for Technology of Plasticity Conference
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• 2002.02a
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• pp.3-10
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• 2002

In this study on machine measuring system based on solid feature was developed. This system was applied with injection mold using 3 dimensional solid modeler for verification. Developed program include pre-processor, main processor, and post processor. In pre-processor there are functions which check intersection, simulate motion of probe and calculate measuring time. Main processor generates measuring path and output NC code in Unigraphics. In post-processor functions that include evaluation of undercut or overcut and display of measuring procedure are offered. In addition analysis module for quality control of measured data on manufactured product was developed with geometric and dimensional tolerance concept. As the result developed program could get stability of system, precision of product, rapidity and cost down of manufacturing process compared with before measuring process.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.7
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• pp.74-79
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• 2000

Integrating a 3D solid modeler with a general purpose FEM code, an automatic nonlinear analysis system of the 3D crack problems has been developed. A geometry model, i.e. a solid containing one or several 3D cracks is defined. Several distributions of local node density are chosen, and then automatically superposed on one another over the geometry model by using the fuzzy knowledge processing. Nodes are generated by the bucketing method, and ten-noded quadratic tetrahedral solid elements are generated by the Delaunay triangulation techniques. The complete finite element(FE) model generated, and a stress analysis is performed. In this system, burden to analysts fur introducing 3D cracks to the FE model as well as fur estimating their fracture mechanics parameters can be dramatically reduced. This paper describes the methodologies to realize such functions, and demonstrates the validity of the present system.

• International Journal of CAD/CAM
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• v.2 no.1
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• pp.55-67
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• 2002

In many areas of industry, it is desirable to have fast and reliable systems in order to quickly obtain suitable solid models for computer- aided analyses. Nevertheless it is well known that the data exchange process between CAD modelers and CAE packages can require significative efforts. This paper presents an approach for geometrical data exchange through triangulated boundary models. The proposed framework is founded on the use of STL file specification as neutral format file. This work is principally focused on data exchange among CAD modelers and FEA packages via STL. The proposed approach involves the definition of a topological structure suitable for the STL representation and the development of algorithms for topology and geometry data processing in order to get a solid model suitable for finite element analysis or other computer aided engineering purposes. Different algorithms for model processing are considered and their pros and cons are discussed. As a case study, a prototype modeler which supports an exporting filter for a commercial CAE package has been implemented.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2002.04a
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• pp.352-356
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• 2002

In this paper, an automated design system of suspension and steering parts is developed. The system automates the processes of 3-D modeling and 2-D drafting of the parts. In addition, the BOM and dimension data of the designed part is also automatically transferred to the database of ERP system. The system is developed by using the functions of parametric design and API(application Programming Interface) of the a commercial solid modeler.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2002.10a
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• pp.139-145
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• 2002

In this study, the geometric modeling has been conducted for 2 models of lower end fitting of advanced LWR fuel using three-dimensional solid modeler, Solidworks. Then, the optimization and the three-dimensional stress analysis using the finite element method has been peformed. The evaluation for the mechanical integrity of 2 models has been peformed based on the stress distribution obtained from the finite element analysis.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.5 no.4
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• pp.723-729
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• 2001

We are able to work on the shared virtual space in Web-based Collaborative Design System using only Internet and Web browser. The users connect to the Solid Modeler Server through m and they create 3D shape and manipulate them variously. Then the users will share 3D objects and two problems can arise. The users must be able to pick the objects effectively which they want to manipulate. When one of the users manipulates a particular object, others should not disturb with the same object. In this paper, picking is implemented not only by computing intersection of mouse pointer with the objects of the virtual world, but also by using capabilities and attributes of scene graph node, by setting bounds intersection testing instead of geometric intersection testing, by limiting the scope of the pick testing, using Java 3D. These methods can reduce the computation of picking and can pick 3D objects effectively and easily using the system of hierarchy. To have effective concurrency, we used shared lock and exclusive lock as the action in work space.