• 한국기계가공학회지
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• 제16권4호
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• pp.147-152
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• 2017

In the present study, we used a loop thermosyphon heat exchanger consisting of condensers with internal fins and external plate fins which are 480 mm wide, 68 mm long, and 1,000 mm high. The heat transfer pipes in the heat exchanger were 15 mm in diameter and 1,000 mm in length, and 98 heat transfer pipes were installed in the heat exchanger. According to the experimental results, as the spaces between the internal discontinuous pins decreased, the frequency of pressure drops increased and changes in temperature at the outlet of the condenser were shown to be a little smaller. Therefore, we can see that as the spaces between internal discontinuous pins decreased, the heat transfer performance increased. For the loop heat pipe heat exchanger consisting of a condenser with internal and plate fins, as the temperature of the air flowing into the condenser increased, the condensation heat transfer rate also increased, and as the condenser refrigerant inflow temperature increased, the condensation heat transfer rate increased as well.

• 한국기계가공학회지
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• 제12권2호
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• pp.20-26
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• 2013

This study focused on how it affects the surface roughness of work piece in cutting SCM415 steel, widely used steel in industry, by TiCN and TiN tools. Following conclusion was drawn from several experiments. The surface roughness of heat treated workpiece was better than that of non heat-treated materials. Moreover, the roughness of surface roughness(Ra 0.25) on feeding rate of 0.05 was better when it was in wet process, rather than dry process. As the feeding rate increases, TiCN coating tool shows better roughness of surface than TiN tool. Also, in heated treatment, TiCN coating tool shows the least straightness dimension deviation at feeding rate of 0.05, 0.15mm/rev, and concave-like R shape appears by the feeding rate orders of 0.05, 0.15, 0.1, 0.125 and 0.075mm/rev.

• 대한치과보철학회지
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• 제54권3호
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• pp.273-279
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• 2016

과도한 치아의 마모는 치수의 병적 변화, 교합 불균형과 기능 및 심미적 문제를 야기할 수 있다. 수직고경의 변화를 동반한 전악보철수복의 경우, 악관절 및 저작근의 통증이나 이상기능 등의 문제를 야기할 수 있으므로 정확한 진단 및 분석, 그리고 단계적인 치료접근이 요구된다. 본 증례는 34세 남자 환자로 전반적인 치아 마모와 부식으로 인해 기능적, 심미적 치아외형 상실을 가지고 있었다. 진단 평가결과 수직고경의 거상을 동반한 전악 보철 수복이 필요한 상태로 진단되었다. 치료계획에 의해 교합안정장치를 이용하여 턱관절을 안정화시킨 뒤 중심위를 채득하고, 거상된 수직고경 상에서 임시치아로 수복하여 경과 관찰하였다. 그 후 CAD-CAM (computer aided design-computer aided manufacturer)을 이용하여 단일구조 지르코니아를 이용한 보철 수복을 시행하였다. 최종 보철 수복 후 환자는 기능 및 형태적으로 매우 만족했으며, 더불어 심미적으로도 좋은 결과를 얻었기에 보고하는 바이다.

• 한국염색가공학회지
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• 제34권2호
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• pp.117-126
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• 2022

In this study, thermoplastic composites were manufactured using ABS(acrylonitrile butadiene styrene), PC(polycarbonate), and POE(polyolefin elastomer), which are thermoplastic plastics. Twin screw extruder and injection molding were used to manufacture thermoplastic composites. When the ABS/PC/POE thermoplastic composite material was manufactured, the POE mass fraction was set to 1 to 5 wt.%, and the thermal and mechanical properties according to the POE mass fraction were analyzed. Based on the physical properties of ABS/PC/POE, a 3D model in the form of an e-bike frame was created. After setting the boundary conditions, when an external load is applied, geometry simulation was performed to predict product performance. The ABS/PC/POE thermoplastic composite material exhibited the best physical properties when the mass fraction of POE was 3 wt.%. In the simulation results for the physical properties of the 3D model in the form of an e-bike frame, the best physical properties were shown when the mass fraction of POE was 2 ~ 3 wt.%. As a result, the manufacturing conditions for ABS/PC/POE thermoplastic composite materials were set, and research was conducted to reduce product development costs and development time.

• 치위생과학회지
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• 제11권4호
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• pp.299-303
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• 2011

The purpose of this case report was to present an example of an esthetic and functional rehabilitation of anterior teeth with tetracycline discoloration and minor morphological abnormality of a 39-year old female. A chairside computer-aided design/computer-aided manufacturing (CAD/CAM) system with CEREC AC was applied for the prosthetic procedure and all ceramic crowns made with lithum disilicate (IPS e.max CAD) restored the esthetic and functional features of sixteen anterior teeth successfully.

• Journal of Korean Dental Science
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• 제9권2호
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• pp.74-80
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• 2016

Even though an immediate denture (ID) is a practical prosthesis, fabricating an ID may be challenging, as unexpected removals of periodontally compromised teeth may occur during an impression procedure. This clinical report introduces a digital approach to a maxillary ID. An intraoral scanner was applied to prevent accidental extraction. A physical cast and a resin pattern of a framework were fabricated with rapid prototyping technology. A proper border and retention was also achieved by an altered cast impression.

• 한국정밀공학회지
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• 제3권4호
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• pp.23-29
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• 1986

CAD라 함은 computer Aided Design의 약자로서, 종종 컴퓨터 지원설계로 번역되고 있다. 그리고, CAM도 computer Aided Manufacturing의 약자로서 컴퓨터 지원제조로 번역된다. 컴퓨터가 실용화되고 설계에의 이용이 가능해졌을 당시는 설계의 자동화(DA : Design Automation)에 대한 기대가 컸다. 그러나 현실로는, 설계자가 설계하는데 있어서 컴퓨터와 주변장치들을 가까이 두고 도구로 이용하게 되었으나, 그것은 주로 제한된 비교적 단순한 제품의자동설계로서, DA의 발전은 예상외로 제자리 걸음을 하고 있었다. 인간을 대신하여 컴퓨터에 설계를 시킨다는 것이 얼마나 어렵다는 것, 특히, 그와같은 Software 개발이 어럽다는 것을 인식하게 되었다. 그래서 <생각하는 일>과 <창조하는 일>과 같이 본래 인간의 본질적인 기능 에 속하는 것을 인간(설계자) 이 하고, <설계하는 일> <제도하는 일> 과 같은 기계적 인 일을 컴퓨터에 시키는 분업이 생각하게 되었다. 이것이 컴퓨터 지원설계(CAD)인 것이다. CAC에 있어서, 설계의 주역은 어디까지나 인간(설계자)에 있으며, 컴퓨터는 설계자의 기계적(비인간적)인 일을 도와주는 도구인 것이다. 이와같이 설계에 있어서 컴퓨터의 위치가 정의된다.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 1996년도 춘계학술대회 논문집
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• pp.271-275
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• 1996

In this paper, an automatic spot inspection system has been developed for camera target lens using the computer aided vision system. The developed system comprises: light source, magnifying optics, vision camera, XY robot, and a PC. An efficient algotithm for the spot detection has been implemented, thus up tof ew micrometer size spots can be effectively identified in real time. The developed system has been fully interfaced with XY robot systenm, PLCs, thus the practical spot inspection system has been implemented. The system has been applied to a practical camera manufacturing process, and showed its efficiency.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2006년도 정기 학술대회 논문집
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• pp.508-513
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• 2006

In construction of RC buildings, the quality of shop and detail drawings is very essential for the quality and safety of buildings. Nevertheless, most of thess works are left to site workers and the requirements about bar detailing such as anchorage and splice have been done without rational design and engineering. The purpose of this research is to develop a computer-aided drawing system of rebars for RC buildings. The system is based on an integrated structural design system, that is SDP. SDP manages an engineering database for structural design information. It provides all the information needed to draw rebar drawings. The drawing system consists of three modules, 1) Structual Plan Drawing System, 2) Shop Drawing System, and 3) Detail Drawing System. It is expected that not only the productivity of detail drawing works but also the quality and safety of buildings will be improved using the rebar drawing system developed in this research.

• 한국정밀공학회지
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• 제19권7호
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• pp.116-124
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• 2002

The planning of part feeder and other manufacturing automation equipments is almost always underestimated. Planning ahead for those crucial pitfalls can permit steps to take to minimize heir impacts, especially if the problems can be discovered in the planning phase, not on the shop floor. Planning process is an engineering process, namely a series of trade-offs. The effective trade-offs in the shortest amount of time can be possible with the help of a computer-aided ngineering (CAE) technique. The main parts of CAE fur part feeder are database system of fabricated workpiece parts, part feeders, part feeder components. In this study, a planning process of part feeder is presented. Especially, a systematic analysis of workpiece parts and part feeders is performed for the design of databases of CAE system.