• Korean Journal of Computational Design and Engineering
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• v.7 no.4
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• pp.211-218
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• 2002

Swept volumes have been used in a wide variety of applications, and the literature contains much discussion of methods for computing the swept volumes in many situations. However, the commercially available CAD systems do not support the operations of generating the swept volumes enough to satisfy a variety of users' needs. In this paper, we present a new, simple and efficient algorithm for computing the swept volume of moving a polyhedron in 3-D region. The screw motion is used to describe the sweep motion of a polyhedron, because of its simplicity and computational advantages. The boundary of a swept volume is the result of combining the envelope surfaces and the partial boundaries at the initial and final position of a polyhedron. Some portions of these boundaries are inside the swept volume. We develop the algorithm to remove these interior portions. Then, to implement our algorithm, it is performed to integrate our program with the commercial CAD software, CATIA.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 1999.05a
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• pp.179-182
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• 1999

A new band pass filter (BPF) prepared by dielectric monoblock and its design techniques are presented. The modeling of the three-pole dielectric monoblock BPF has been carried out by CAD. The equivalent circuit of the BPF was established by transmission lines and lumped capacitors. The transmission line characteristic impendances were computed using 2-D FEM. The BPF for PCS has been designed to have a 60 MHz pass-bandwidth with center frequency of 1960 MHz and an attenuation pole at below the passband using a commercial 3-D structure simulator.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.31 no.2 s.257
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• pp.260-268
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• 2007

Demand for the use of 3D CAD DMU systems over the Internet environment has been increased. However, transmission of commercial 3D kernels has delayed the communication effectiveness due to the kernel size. Light weight CAD geometric kernel design methodology is required for rapid transmission in the distributed environment. In this paper, an assembly data structure suitable for the top-down and bottom-up assembly models has been constructed. Part features are stored without a hierarchy so that they are created and saved in no particular order. In particular, this paper proposes a new assembly representation model, called multi-level assembly representation (MAR), for the PDM based assembly DMU system. Since the geometric kernel retains assembly hierarchy and topological information, it is applied to the web-viewer for the PDM based DMU system. Effectiveness of the proposed geometric kernel is confirmed through various case studies.

• Journal of the Korean Association of Geographic Information Studies
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• v.3 no.3
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• pp.69-76
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• 2000

This study deals with development GIS application using web-based CAD, this application serves to user, designer, manager that more convenient and various functions. Development to this application, collect attribute data from fieldwork and geographic data from cadastral map and aerial survey map and then development to user interface using HTML, JavaScript, ASP, Whip ActiveX control. This application's characters are as follows ; First, system designer designed that anyone who have basic knowledge about web and CAD can develop this application. A system structure simplification by 2-Tier. Geographic information use DWF(drawing web format) file and attribute information use DBMS in consideration of extension. Second, system manager can service independently GIS in Web need not high priced GIS engine, so more economical. Third, internet user get service GIS information and function that search of information, zoom in/out, pan, print etc., if you need more functions, add function without difficultly. Developed application as above, not only save volume but fast of speed as use vector data exclude character and image data. Also, this application can used by means of commercial and travel information service but also various GIS service of public institution and private in web.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.24 no.1
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• pp.61-67
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• 2011

This study is concerned with the shape optimization of structural members frequently found in critical area in a structure system, that is, highly stressed zone. Isogeometry analysis is well known to be the very efficient way to integrate the geometric modeling(CAD) and computational analysis(CAE). This can be accomplished by directly using the geometric modeling by NURBS(Non-Uniform Rational Basis Spline). In this study, an efficient computer code adopting the isogeometry concept has been developed for the structural analysis, in which CAD information can be directly used in the finite element modeling. In order to show the validity of the present code, the present results are compared with those by using the commercial package, that is, MSC/NASTRAN. The present isogeometric analysis procedure has been integrated with the optimization procedure to deal with the optimization problem found in the context of structural mechanics. The present system has been successfully applied to the shape optimization of cantilever structure having bracket. From the present study, it can be seen the validity of the present approach and computer codes developed in this study. This paper ends with some discussions about the practical usefulness of the present approach which is based on isogeometry analysis, and extension of the present study.

• The Journal of Advanced Prosthodontics
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• v.9 no.3
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• pp.200-207
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• 2017

PURPOSE. In this study, three bioceramic materials, [IPS Empress CAD (Ivoclar), IPS e.max CAD (Ivoclar), and Lava Ultimate CAD (3M ESPE)] were treated with three commercial mouthrinses [Listerine, Tantum Verde, and Klorhex]; and changes in colour reflectance and surface roughness values were then quantitatively assessed. MATERIALS AND METHODS. One hundred and twenty ceramic samples, with dimensions of $2{\times}12{\times}14mm$, were prepared and divided into nine sample groups, except three control samples. The samples were immersed in the mouthrinse solutions for 120 hrs, and changes in colour reflectance and surface roughness values were measured by UV light spectrophotometry (Vita Easyshade; VITA Zahnfabrik) and by profilometer device (MitutoyoSurftest SJ-301), respectively. The change of surface roughness was inspected by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). RESULTS. There was a positive correlation between the ${\Delta}E$ and increase in the surface roughness. Two of the ceramic materials, IPS Empress and Lava Ultimate, were affected significantly by the treatment of the mouthrinse solutions (P<.05). The most affecting solution was Tantum Verde and the most affected material was Lava Ultimate. As expected, the most resistant material to ${\Delta}E$ and chemical corrosion was IPS e max CAD among the materials used. CONCLUSION. This work implied that mouthrinse with lower alcohol content had less deteriorating effect on colour and on the surface morphology of the bioceramic materials.

• The Journal of Information Technology and Database
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• v.6 no.1
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• pp.47-57
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• 1999

CITIS(Contractor Integrated Technical Information Service) is a service standard which specifies guidelines which are required for the fulfillment of a contract between a purchaser and a supplier. It was initiated as a military standard and is now becoming a commercial standard. In this paper, we propose how the guidelines, which were usually developed by Client/Server methods in previous works, can be implemented in WWW environments, and show a prototype which can be used for the confirmation of CAD drawings between contractors(purchaser and provider). We have a hope our study can provide a small foundation for the building of CITIS references.

• 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 Korean Society of Precision Engineering Conference
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• 1993.10a
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• pp.166-170
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• 1993

This paper introduces API(Application Programming Interface) development technology for improving design efficiency which is concerned with special product design environment and development lead time of company's own. Even though most companies commercial CAD/CAM/CAE procucts. For reducing procuct development cycles and improving design efficiency. We have to automatize design processes through the standadizarion and parameterization and develop the specialized utilities as a infrastructure. The proposed API development methodology provides improved automatic 2D,3D modeling procedures and useful user interfaces at a small fraction of the cost and design effort.

• Transactions of Materials Processing
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• v.9 no.3
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• pp.226-232
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• 2000

The optimal blank design method by sensitivity analysis has been applied to the formings of oil-pan, tailored blank and front panel as the examples. Die geometry is prepared by a commercial CAD system. Excellent results has been obtained between the numerical results and the target contour shapes. Through the investigation, the proposed systematic method of optimal blank design is found to be effective in the practical forming processes.