• Korean Journal of Construction Engineering and Management
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• v.6 no.1 s.23
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• pp.65-72
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• 2005

The 3D objects far representing artificial element in building project can be easily organized in 4D system. However, the civil engineering projects need a composing technology of irregular triangulate network because the projects generally include earthwork of large scale that consists of cutting, filling, and excavating work. It Is very difficult to represent earthwork status as 3D object type because the earthwork in highway or railway projects is being progressed on the natural geographical features. That is, a composing technology of irregular triangulate networks necessary function to simulate natural site condition as 3D object in 4D system. This study suggests a new composing technology of irregular triangulate network that 3D objects can be automatically generated by attribute in each layer.

• 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.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.32 no.12C
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• pp.1194-1202
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• 2007

In this paper, we proposed a blind watermarking algorithm to apply to the rapid prototyping system. The 3D mesh model is used in the step of the CAD modeling before the making of the prototype system of the rapid prototyping system. STL type mesh modeling which is used in this system reduces the error of the system and improves the accuracy of the system. In the step of the CAD modeling, some transformations which do not change the model accuracy are used, but some transformations which change the model accuracy are not used because the mesh model error is related to the accuracy of the prototype system. Most watermarking algorithms embedded a specific random noise as the watermark information into the model. These kinds of the algorithms are not proper to the 3D model watermarking. The proposed algorithm can be used for the accurate prototyping system because it does not change the model after the watermark embedding This means it can be used for the copyright marking and the data integrity.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2003.06a
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• pp.1467-1470
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• 2003

In order to enhance the productivity of design and manufacture of injection molds, various computer-aided systems have been developed and introduced to mold manufacturers. The customized 3-D CAD systems for mold design is one of the most representative computer-aided system. However, these systems usually do not provide a convenient way to access and manage design knowledge implemented in them. To overcome this shortage, knowedge-based engineering systems have been developed, and now they are imbedded as modules of commercial CAD systems. In this paper, we introduced a 3-D design system for standard mold base based on Knowledge Fusion, a commercialized KBE system imbedded in Unigraphics. By introducing KBE system, design knowledge can be exposed to the users and modified by the end-users.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2009.11a
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• pp.269-272
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• 2009

The environment of Ubiquitous in terms of improvement is being expanded to various fields and time enabled system. Thus, a real-time spatial information management system has been developed by integrating a human movement detection system into a SICS(Spatial Information Control System) engine that can integrally manage inside spatial information extracted from 3D CAD and outside spatial information of GIS. The add-on program was developed to extract spatial information necessary for the SICS engine from 3D CAD information, and a human movement detection system was developed. Test bed was operated for 2weeks and indoor human flow information was found out by zone. Also, the direction of future research was decided through a test bed.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.9 no.2
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• pp.270-275
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• 2008

The straight bevel gear for automobile part has been manufactured by the cold forging instead of the gear machining tool for the mass production. The application to CAD/CAM system has been necessary in order to develop the precision product quickly by forging through the minimization of trial and error and confirm the reproducibility. In the study, the straight bevel gear with the crown teeth has been modelled by the CAD/CAM system. The master gear after the gearing test has been machined after the modelling, NC data generation and verification. The die for forging and the jig for machining has been manufactured using the master gear.

• Korean Journal of Computational Design and Engineering
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• v.19 no.1
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• pp.41-49
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• 2014

For the reuse of the existing 3D block model of a ship, we analyze the hull modeling process using AVEVA Marine which is a representative CAD (Computer-Aided Design) system for the shipbuilding. In the AVEVA Marine environment where the design engineer makes 3D model on the 2D view that is so-called 2.5D, it cannot be possible to copy to reuse the block model just simply copying the 3D feature model itself like in the general mechanical CAD system or Smart Marine 3D which are on the basis of the 3D model representation. In this paper, we analyze the scheme file where the 3D model is defined in AVEVA Marine so that we develop the program for the block copy and the translation using this scheme file. It is significant that this program can be immediately available as a real-world application on the AVEVA Marine environment.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.1
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• pp.1-7
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• 2012

It is necessary to construct the process automation system to improve the design efficiency and procure the higher design quality on the field of ship building. To construct this system, the shipbuilding companies should improve the 3D CAD/CAM system customized to the ship design and the software about design information management which could solve the conflict problem between the several related design division at the same time. The typical example is the Hole-plan process in the ship-building design. For the request of additional holes from outfitting division, the hull design division checks the compatibility conditions and reflects these holes to the hull panels if acceptable. if not, the requests are rejected and sent back to the outfitting division. These serial processes are not simple and require the tedious communication, discussion, and the complicated drawings. This article gives a basic introduction to the process of hole-plan system and proposes a strategy to automate its process.

• Journal of Technologic Dentistry
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• v.33 no.2
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• pp.137-145
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• 2011

Purpose: To evaluate the accuracy of zirconia copings in terms of clinical verified for the clinical application of CAD/CAM. Methods: Zirconia copings (n=5) were prepared using CAD/CAM system and were sintered using the relevant electrical induction furnace, which uses a 2h sintering program with a maximum temperature of $1500^{\circ}C$. The copings placed at the models and the interval values were measured. Results: The meas interval values between the die and the zirconia copings were $44.14{\mu}m$(A), $44.57{\mu}m$(B), $44.72{\mu}m$(C). 51.05 ${\mu}m$(D). Conclusion: The maximum interval values between the die and the zirconia copings were $51.3{\mu}m$ which is acceptable for clinical use. ${\mu}m$ Proper understanding of the test conditions will help enhancing the accuracy of zirconia coping.

• Korean Journal of Construction Engineering and Management
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• v.9 no.2
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• pp.125-135
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• 2008

A controller who is responsible for visiter's safety makes a decision about measures for visiter safety in human-based decision making process. Many potential accidents that are caused by human error lurk in results of the process. The accidents can be decreased by changing the decision making process from human-based into technology-based. Technology-based decision making process can catch a controller's attention through data filtering, alarm filtering, and so on. So, the controller can get information on occurrence of an unforeseen accident pro-actively. The objective of this study is to suggest a concept of 3D spatial information control system for visitor flow control in multi complex building using technology-based decision making process. This study shows utilization of the system and contribution.