• Journal of the Korea Academia-Industrial cooperation Society
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• v.17 no.11
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• pp.740-745
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• 2016

Cables are installed for tens of thousands of connections between various pieces of equipment to operate and control a commercial ship. The correct shortest-route data is necessary since these are complicated cable installations. Therefore, an overfill interval commonly exists in the shortest paths for cables as estimated by Dijkstra's algorithm, even if this algorithm is generally used. It is difficult for an electrical engineer to find the overfill interval in 3D cable models because the occupancy rate data exist in a data sheet unlinked to three-dimensional (3D) computer-aided design (CAD). The purpose of this study is to suggest a visualization method that displays the cable path and overfill interval in 3D CAD. This method also provides various color visualizations for different overfill ranges to easily determine the overfill interval. This method can reduce cable-installation man-hours from 7,000 to 5,600 thanks to a decreased re-installation rate, because the cable length calculation's accuracy is raised through fast and accurate reviews based on 3D cable visualization. As a result, material costs can also be reduced.

• Journal of the Korea Convergence Society
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• v.8 no.4
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• pp.131-137
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• 2017

In the present study, we developed the 4D CT data generation program from CAD-based models. To evaluate the developed program, a CAD-based respiratory motion phantom was designed using CAD software, and converted into 4D CT dataset, which include 10 phases of 3D CTs. The generated 4D CT dataset was evaluated its effectiveness and accuracy through the implementation in radiation therapy planning system (RTPS). Consequently, the results show that the generated 4D CT dataset can be successfully implemented in RTPS, and targets in all phases of 4D CT dataset were moved well according to the user parameters (10 mm) with its stationarily volume (8.8 cc). The developed program, unlike real 4D CT scanner, due to the its ability to make a gold-standard dataset without any artifacts constructed by modality's movements, we believe that this program will be used when the motion effect is important, such as 4D radiation treatment planning and 4D radiation imaging.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.11 no.1
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• pp.1-9
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• 2002

Reverse engineering is an emerging technology to obtain CAD models from existing physical parts in the case that CAD models are not available or paras are changed an(1 modified so that new CAD models for final parts are necessary. Reverse engineering helps designers to quickly generate computer interpretable data from existing Physical objects So it is applying for field of Rapid Prototyping NC Processing CAE, Inspection and so on. The objective of this study is to develop the software that deals with unorganized point data and quickly obtains CAD model. In this paper, several models such as human\`s bone, car, are experimented by the proposed methods.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2003.04a
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• pp.305-312
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• 2003

Recently, with a progressive development of hardware of computer, the internet and network technology, the environment of construction varies rapidly due to increase the complex form in structure shape and system. With variations, the CAD system for design and products also varies from 2D system to 3D system. This study mainly deals with the methodology of automatic connection design of 3D CAD system, steel connection system (XSteel) using macro. First, using design program in the steel connection system, Xsteel, the joint connection macro will be made up and established the detail classes of design. The next, Database Program (Converter Program) related to the general structural analysis program (MIDAS) and the steel connection program (Xsteel) is constructed for data interface between two programs. From this study, if the merits of 3D CAD system and converter program are utilized well, it is expected that the time needed in modeling and the amounts due to material loses decrease gradually.

• Proceedings of the KSME Conference
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• 2008.11a
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• pp.181-185
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• 2008

Recently, the Virtual Reality(VR) became one of the most powerful tools in making media files. In the field of engineering, while it is increasing to use 3D CAD model in the process of design to manufacturing, the VR is not popular in comparison with media business. XVL(eXtensible Virtual Reality Markup Language) is one of XML(eXtensible Markup Language) which is a standard web media language. XVL provides the connection between 3D CAD data and virtual reality, and it can be easily published through internet for the engineering purpose. In this study, a web based VR model for major components in a nuclear power plant has been developed by using XVL and corresponding 3D CAD data. The proposed model is expected to be used in the engineering field to cooperate among experts, and also, it will provide more plausible explanation to ordinary people.

• Journal of the Computational Structural Engineering Institute of Korea
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• v.27 no.5
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• pp.345-352
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• 2014

In this paper, the CAD data for the optimal shape design obtained by isogeometric shape optimization is directly used to fabricate the specimen by using 3D printer for the experimental validation. In a conventional finite element method, the geometric approximation inherent in the mesh leads to the accuracy issue in response analysis and design sensitivity analysis. Furthermore, in the finite element based shape optimization, subsequent communication with CAD description is required in the design optimization process, which results in the loss of optimal design information during the communication. Isogeometric analysis method employs the same NURBS basis functions and control points used in CAD systems, which enables to use exact geometrical properties like normal vector and curvature information in the response analysis and design sensitivity analysis procedure. Also, it vastly simplify the design modification of complex geometries without communicating with the CAD description of geometry during design optimization process. Therefore, the information of optimal design and material volume is exactly reflected to fabricate the specimen for experimental validation. Through the design optimization examples of elasticity problem, it is experimentally shown that the optimal design has higher stiffness than the initial design. Also, the experimental results match very well with the numerical results. Using a non-contact optical 3D deformation measuring system for strain distribution, it is shown that the stress concentration is significantly alleviated in the optimal design compared with the initial design.

• Journal of the Korean Home Economics Association
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• v.35 no.5
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• pp.249-264
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• 1997

The purpose of this study was to provide the reference information for user and potential users of apparel CAD system is Korea. Two interviews were carried out for the study. The apparel CAD system of Assyst, Gerber and Yuka was selected for technical comparative study. The results were as follows: 1. The future development of the apparel CAD system is the transfer of the developed pattern design from a 3D design system and of CIM concept. 2. The share of data is working closely in a module function. So the Assyst system provide connectivity and communication between all apparel CAD system's module and other automation programs. This system is suitable for CIM production line. 3. The Gerber system is developed the Apparel CAD system which is given by the CAM system's technical ability. This system is given high insurance of ability to the service and data transportation with other systems from users in the Korea. 4. The Yuka system is developed pattern making by the Apparel CAD system. This system's different methods which is compared with other systems are the split grading and auto pattern making. So this system is suitable for users which want to product many items and a little amount garment by using the Apparel CAD system.

• The Journal of Korean Academy of Prosthodontics
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• v.60 no.2
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• pp.202-210
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• 2022

Recently with the advance in digital dentistry, the fabrication of dentures using computer-aided design and computer-aided manufacturing (CAD-CAM) is on the rise. The denture designed through a CAD software can be produced in a 3-dimensional manufacturing process. This process includes a subtractive processing method such as milling and an additive processing method such as 3D printing and in which it can be applied efficiently in more complex structures. In this case, complete dentures were fabricated using Stereolithography (SLA)-based 3D printing to shorten the production time and interval of visits in patient with physical disabilities due to cerebral infarction. For definitive impression, the existing interim denture was digitally replicated and used as an individual tray. The definitive impression obtained with polyvinyl siloxane impression material was including information about the inclination and length of the maxillary anterior teeth, vertical dimension, and centric relation. In addition, facial scan data with interim denture was obtained so that it can be used as a reference in determination of the occlusal plane and in arrangement of artificial teeth during laboratory work. Artificial teeth were arranged through a CAD program, and a gingival festooning was performed. The definitive dentures were printed by SLA-based 3D printer using a FDA-approved liquid photocurable resin. The denture showed adequate retention, support, and stability, and results were satisfied functionally and aesthetically.

• Korean Journal of Computational Design and Engineering
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• v.4 no.3
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• pp.200-209
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• 1999

This paper presents a 3D-conferencing system as a prototype implementation of concurrent and distributed engineering environment using CORBA-Java and SDAI-Java. The system consists of some client and server objects that communicate with each other via ORB. The server objects use lightweight version of current working draft of SDAI-Java to access STEP product data models, and the client objects provide user-friendly graphical interface. The proposed system can be used for communicating with 3D CAD data between remote designers, manufactures and customers regardless of he H/W or S/W platforms they use.

• Journal of Computational Design and Engineering
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• v.2 no.2
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• pp.96-104
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• 2015

Aluminum die casting is an important manufacturing process for mechanical components. Die casting is known to be more accurate than other types of casting; however, post-machining is usually necessary to achieve the required accuracy. The goal of this investigation is to develop machining- free aluminum die casting. Improvement of the accuracy of planar and cylindrical parts is expected by correcting metal molds. In the proposed method, the shape of cast aluminum made with the initial metal molds is measured by 3D scanning. The 3D scan data includes information about deformations that occur during casting. Therefore, it is possible to estimate the deformation and correction amounts by comparing 3D scan data with product computer-aided design (CAD) data. We corrected planar and cylindrical parts of the CAD data for the mold. In addition, we corrected the planar part of the metal mold using the corrected mold data. The effectiveness of the proposed method is demonstrated by evaluating the accuracy improvement of the cast aluminum made with the corrected mold.