• 한국전산유체공학회:학술대회논문집
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• 2007.04a
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• pp.103-107
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• 2007

Computational Fluid Dynamics (CFD in short) approach is now playing an important role in the engineering process recently. Generating proper grid system for the region of interest in time is prerequisite for the efficient numerical calculation of flow physics using CFD approach. Grid generation is, however, usually considered as a major obstacle for a routine and successful application of numerical approaches in the engineering process. CFD approach based on the unstructured grid system is gaining popularity due to its simplicity and efficiency for generating grid system compared to the structured grid approaches. In this paper an automated triangular surface grid generation using CAD surface data is proposed According to the present method, the CAD surface data imported in the STL format is processed to identify feature edges defining the topology and geometry of the surface shape first. When the feature edges are identified, node points along the edges are distributed. The initial fronts which connect those feature edge nodes are constructed and then they are advanced along the CAD surface data inward until the surface is fully covered by triangular surface grid cells using Advancing Front Method. It is found that this approach can be implemented in an automated way successfully saving man-hours and reducing human-errors in generating triangular surface grid system.

• Journal of the Korean Home Economics Association
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• v.32 no.2
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• pp.207-218
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• 1994

최근 컴퓨터 디자인을 비롯한 컴퓨터의 응용은 의류패션과 직물 산업분야에 있어서 디자인 및 생산공정이 자동화되는 등 의류 디자인 및 제작에 중요한 역할을 하고 있다. 본연구의 목적은 컴퓨어화 사화의 이행에 따른 1) CAD를 포함한 컴퓨터 시스템의 의류학에의 응용실태 2) 컴퓨터 응용에 대한 인식 및 미래의 방향 3) 의류학내의 전반적인 문제점과 해결방안 등에 대하여 연구하고자한다. 연구방법은 전국 의류학 관련교육과(43개 4년제 대학의 교수) 110명을 대상으로 설문지법을 사용하였으며 회수된 58부 (53% 회수율)를 SAS로 통계처리하여 Likert's mehod of summated ratings로 분석하였다. 연구결과에 따르면 CAD는 11%의 대학에서 컴퓨터개론이 25%의 대학에서 Telecom-munication Spreadsheet Database 는 각각 4%의 대학에서 강의되고 있다. CAD 는 주로 다른과목에 포함되어 "몇주"(4%) "몇일(4%)" 정도 강의되고 있으며 컴퓨터개론은 다른과목에 포함되어"반학기"정도 강의 되는경우(14%) 가 가장많은 것으로나타났다. 또한 37%의 대학에서 앞으로 5년내에 의류학에 컴퓨터디자인 및 컴퓨터 시스템을 도입할 계획으로 있으며 특히 CAD에 대한 관심이 높았다. 64%의 대학이 의류학과 건물내에 컴퓨터 시설이 갖추어져 있지 않아 모든교수들이 컴퓨터교육을 위한 시설 재점비가 필요하다고 하였다. 컴퓨터활용의 부족이 의류학 관련학과의 취약부분으로 인식욈에 따라 앞으로 CAD에 관한 연구 및 컴퓨터 관련 수업의 개설, 시설 확충등이 보완되어야 할 것으로 나타났다. 본연구 결과는 한국내 의류관련학과의 CAD를 포함한 컴퓨터의 응용실태와 성향을 실증적으로 조사분석함으로써 앞으로 나아갈 방향을 제시하고 미국과의 비교분석을 통하여 의류학과 응용이 우리 실정에 맞게 정착되는데 도움이 될것으로 기대된다.

• Journal of the Korean Academy of Esthetic Dentistry
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• v.17 no.1
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• pp.23-30
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• 2008

Application of CAD/CAM is changing the way partial or full veneer all ceramic restoration is made. CAD/CAM systems, which were used mainly in other industries, have been developed and introduced for the dental purposes recently. It produced a flood of information on the CAD/CAM systems. It also influenced the development of restorative materials and all ceramic is substituting the traditional restorative materials of gold, composite resin and metal. Price increase of gold and other raw materials made the all ceramic more appealing. The introduction of a CEREC 3D system was innovative in several ways. Image of the prepared tooth is captured by camera and impression taking is unnecessary. Restoration can be delivered to the patient on one appointment and it will satisfy the demand of busy patients. One-day treatment with direct CAD/CAM system saves time compared to indirect CAD/CAM system. More superior restoration can be produced if lab work such as the adaptability check and shade selection is cooperated with lab technician. Short working time and comparably superior shade compatibility of color block was close to ideal. In the future, restorations with better quality can be fabricated in less time to busy patients thanks to the development of CAD/CAM system and dental materials.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.8 no.5
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• pp.979-983
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• 2007

In this thesis, a strip layout drawing of LCD S/C (shield case) was prepared. In the press die, strip layout drawing is a major factor that decides the mass production of a product. The 3D CAD/CAM system was applied for the easy correction of the interference factor with other parts to be mounted. The material use ratio was enhanced to 60.17% by optimizing the blank layout and strip layout in double width array. Furthermore, the flatness of the product was made to fit the requirements by adding the bidding process intensively on the notching part where the occurrence of the change in shape is expected owing to the thin material. For the 3D CAD/CAM software, Unigraphics NX3.0 was used. The strip layout drawing was prepared in 12 processes.

• The Journal of Advanced Prosthodontics
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• v.11 no.6
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• pp.305-312
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• 2019

PURPOSE. The purpose of this study was to compare computer-aided design/computer-aided manufacturing (CAD/CAM) abutment and prefabricated abutment in Morse taper internal connection type implants after cyclic loading. MATERIALS AND METHODS. The study was conducted with internal type implants of two different manufacturers (Group Os, De). Fourteen assemblies were prepared for each manufacturer group and divided into 2 groups (n=7): prefabricated abutments (Os-P, De-P) and CAD/CAM abutments (Os-C, De-C). The amount of axial displacement and the removal torque values (RTVs) were measured before and after cyclic loading (10⁶ cycles, 3 Hz with 150 N), and the tensile removal force to dislodge the abutments was measured after cyclic loading. A repeated measures ANOVA and a pattern analysis based on the logarithmic regression model were conducted to evaluate the effect of cyclic loading on the axial displacement. The Wilcoxon signed-rank test and the Mann-Whitney test was conducted for comparison of RTV reduction% and tensile removal forces. RESULTS. There was no significant difference between CAD/CAM abutments and prefabricated abutments in axial displacement and tensile removal force; however, significantly greater RTV reduction% after cyclic loading was observed in CAD/CAM abutments. The correlation among the axial displacement, the RTV, and the tensile removal force was not significant. CONCLUSION. The use of CAD/CAM abutment did not significantly affect the amount of axial displacement and tensile removal force, but presented a significantly greater removal torque reduction% than prefabricated abutments. The connection stability due to the friction at the abutment-implant interface of CAD/CAM abutments may not be different from prefabricated abutment.

• Archives of design research
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• v.17 no.1
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• pp.289-298
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• 2004

With the advance of digital technology, development of exclusive CAD system for fashion textile that may suggest the future of fashion textile industry is increasingly accelerated. To build up the foundation of digital culture, it is required for fashion textile industry to develop goods with high value added and make rapid change of production system, and actually, exclusive programs are being developed to meet with the desire. Present study considers the vicissitude of fashion textile and the composition and characteristics of design system, and compares and analyses a variety of design developments of digital fashion textile. And it systemizes the expansion and change of creative digital pattern designs that are developed differing from existing graphic program, the expression of suitable textile texture, and the simulation effect by three-dimension modeling. By separating the usage of CAD system for fashion textile into designing and producing aspects, it also focuses on increasing the usage of exclusive CAD system for fashion textile.

• Journal of Korea Multimedia Society
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• v.10 no.5
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• pp.594-603
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• 2007

This paper proposes a watermarking scheme for 3D CAD design drawing. In the proposed scheme, we embed binary watermarks into line, arc, and polygon face components that are the basic component of 3D CAD design drawing. The embedding target component can be selected randomly among three components or by the component distribution in drawing. In line components, a watermark bit is embedded into the ratio of the length of a target line and an average length of lines that are connected into a target line. Furthermore, a watermark bit is embedded into a curvature radius on the basis of a center point in a arc component and also is embedded into a ratio of two sides in a polygonal face component. Experimental results verified that the proposed watermarking has the robustness against Format conversion, rotation translation, scaling, cropping, and layer cutting and also SNR of watermarked component is about 39.89-42.50 dB.

• Fashion & Textile Research Journal
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• v.18 no.6
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• pp.766-775
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• 2016

In the era of globalization and unlimited competition, Korean universities need a breakthrough in their education system according to the changing education landscape, such as lower graduation requirements to cultivate more multi-talented convergence leaders. While each student has different learning capabilities, which results in different performance and achievements in the same class, the uniform education that most universities are currently offering fails to accommodate such differences. Blended learning, synergically combining offline and online classes, enlarges learning space and enriches learning experiences through diversified tools and materials, including multimedia. Recently, universities are increasingly adopting video contents and on-offline convergence learning strategy. Thus, this study suggests a teaching method based on blended learning to more effectively teach existing pattern CAD and virtual CAD in the Apparel Pattern CAD class. To this end, this researcher developed a teaching-learning method and curriculum according to the blended learning phase and video-based contents. The curriculum consisted of 2D CAD (SuperAlpha: Plus) and 3D CAD (CLO) software learning for 15 weeks. Then, it was loaded to the Learning Management System (LMS) and operated for 15 weeks both online and offline. The performance analysis of LMS usage found that class materials, among online postings, were viewed the most. The discussion menu most accurately depicted students' participation, and students who did not participate in discussions were estimated to check postings less than participating students. A survey on the blended learning found that students prefer digital or more digitized classes, while preferring face to face for Q&As.

• Journal of The Korean Digital Architecture Interior Association
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• v.12 no.4
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• pp.117-124
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• 2012

The importance of the digital architecture is increasing more ever. Currently, CAD and 3D programs are used as design fields, but the BIM (building information modeling) is gradually interested. BIM is mandatory on the project more than 50 billion won ordered by the government since 2012, it will be expanded to a total of government orders by 2016. University needs to evaluate teaching methods and computer-aided design environments such as CAD and BIM. In this paper, we surveyed computer-aided design environments and teaching methods for 73 students at the J University of Department of architectural engineering. Main results are as follows: 1. Hardlock is uncomfortable but necessary program for the computer management. 2. The desk placement considering the behavior of the design students results in higher satisfaction. 3. Because a CAD subject was a difficult course content and progress is fast, students thought it is difficult to follow. Especially, first-year students answered it is difficult to learn program and understand the structure of the building at the same time. 4. First-year students want to learn CAD more. Second-, third-, fourth-year students want to learn Photoshop more. Supplement for these classes is required. 5. Students answered that a teaching method of a CAD subject would be good to their own practice after the professor demonstrates for students. The senior's assistance is also a high effective way in the class. 6. During class, students' activities such surfing the web and Kakao Talk on a smartphone disrupt the class, there is a need to regulate by a rule such as disconnect computers from a network and against using smartphone. Although the Internet with the popularization of smartphones confers a benefit on modern life, it causes damage to us. This is a hard part for a salaried workers as well as students studying equally. The self management is required and a professor needs to control and restraint in a university classroom. The professor's continuing interest to students can increase the effectiveness of learning.

• Journal of the Korean Society for Precision Engineering
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• v.16 no.12
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• pp.109-118
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• 1999

The objective of this research is to develop an effective inspection planning strategy for sculpture surfaces in OMM(On-Machine Measurement) process. As a first step, effective measuring point locations are determined to obtain optimum results for given sampling numbers. Two measuring point selection methods are suggested in this study based on newly proposed CAD/CAM/CAI integration concept: (1) by the prediction of cutting errors, (2) by considering cutter contact points to avoid the measurement errors caused by cusps. As a next step, the TSP(Traveling Salesman Problem)algorithm is applied to minimize the probe moving distance. Appropriate simulations and experiments are performed to verify the proposed inspection planning strategy in this study, and the results are analyzed.