• 한국생산제조학회지
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• 제26권1호
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• pp.6-12
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• 2017

In a large 3D printer when the cooler, which cools the filament, acts in one direction, the area directly exposed to the cooling is cooled to the proper temperature. However, the cooling effect on the opposite area is relatively less. It was found in experiments that filaments with a thickness of over 2 mm exhibit the cooling problem in one directional cooling. Consequently, cooling was performed to prevent the flow-down and to produce firm support leading to an improvement in product quality in extrusion. Further, the lay-up of a 3D printer with five guides combined with a duct was achieved. Analysis showed that the improvement in the cooling effect enables stable extrusion and lay-up and thus, reduces fabrication time.

• Maxillofacial Plastic and Reconstructive Surgery
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• 제40권
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• pp.2.1-2.7
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• 2018

With the development of computer-aided design/computer-aided manufacturing (CAD/CAM) technology, it has been possible to reconstruct the cranio-maxillofacial defect with more accurate preoperative planning, precise patient-specific implants (PSIs), and shorter operation times. The manufacturing processes include subtractive manufacturing and additive manufacturing and should be selected in consideration of the material type, available technology, post-processing, accuracy, lead time, properties, and surface quality. Materials such as titanium, polyethylene, polyetheretherketone (PEEK), hydroxyapatite (HA), poly-DL-lactic acid (PDLLA), polylactide-co-glycolide acid (PLGA), and calcium phosphate are used. Design methods for the reconstruction of cranio-maxillofacial defects include the use of a pre-operative model printed with pre-operative data, printing a cutting guide or template after virtual surgery, a model after virtual surgery printed with reconstructed data using a mirror image, and manufacturing PSIs by directly obtaining PSI data after reconstruction using a mirror image. By selecting the appropriate design method, manufacturing process, and implant material according to the case, it is possible to obtain a more accurate surgical procedure, reduced operation time, the prevention of various complications that can occur using the traditional method, and predictive results compared to the traditional method.

• 대한치과보철학회지
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• 제55권1호
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• pp.94-99
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• 2017

CAD/CAM (computer-aided design/computer-aided manufacturing) 기술을 이용한 인레이 및 여러 고정성 보철물의 제작이 보편화되고 구강내 스캐너가 널리 보급되면서 디지털 치의학의 개념이 치과 보철학 분야 전반에 적용되고 있다. 그러나 가철성 보철 부분에서는 디지털 개념의 적용이 쉽지 않으며 기존의 주조 방식에 많이 의존하고 있다. 따라서 가철성 보철물의 제작 과정에 이런 개념을 적용해보려는 시도는 중요한 의미가 있다. 본 증례에서는 하악 Kennedy class III 무치악 환자에서 보철적, 심미적 요구에 의한 교합고경의 증가와 함께 CAD 및 쾌속조형술(RP, rapid prototyping)을 이용한 가철성 국소의치를 제작하였다. CAD를 이용하여 서베잉 및 국소의치 금속 구조물을 설계하였으며, 쾌속조형술은 금속 구조물을 주조하기 위한 레진 패턴 제작에 이용하였다. 9개월 간의 임상적 관찰 기간 동안 만족스러운 심미적, 기능적 결과를 얻어 이를 보고하고자 한다.

• 대한치과의사협회지
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• 제50권3호
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• pp.110-117
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• 2012

Dental computer-aided design (CAD) and computer-aided manufacturing (CAM) technology have rapidly progressed over the past 30 years. The technology, which can be used in the dental laboratory, the dental office and the form of production centers, has become more common in recent years. This technology is now applied to inlays, onlays, crowns, fixed partial dentures, removable partial denture frameworks, complete dentures, templates for implant installation, implant abutments, and even maxillofacial prostheses. Dentists and dental technicians, who want to use these techniques, should have certain basic knowledge about that. This article gives an overview of CAD/CAM technologies, histories and how it applies in prosthetic dentistry.

• 마이크로전자및패키징학회지
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• 제12권1호
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• pp.59-63
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• 2005

금속-강유전체-반도체 전계효과 트랜지스터 (MFS/MFISFET)의 동작 특성을 technology computer-aided design (TCAD)과 simulation program with integrated circuit emphasis (SPICE)를 결합하여 전산모사하는 방법을 제시하였다. 복잡한 강유전체의 동작 특성을 수치해석을 이용하여 해석한 다음, 이를 이용하여 금속-강유전체-반도체 구조에서 반도체 표면에 인가되는 표면 전위를 계산하였다. 계산된 TCAD 변수인 표면 전위를 전계효과 트랜지스터의 SPICE 모델에서 구한 표면 전위와 같다고 보고게이트 전압에 따른 전류전압 특성을 구할 수 있었다. 이와 같은 방법은 향후 MFS/MFISFET를 이용한 메모리소자의 집적회로 설계에 매우 유용하게 적용될 수 있을 것이다.

• 국제학술발표논문집
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• The 3th International Conference on Construction Engineering and Project Management
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• pp.1318-1323
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• 2009

In recent years, dramatic advances in information technology have motivated the construction industry to improve its productivity. Computer-based information technology includes Computer-Aided Design (CAD), Computer-Aided Engineering (CAE), Computer-Aided Manufacturing (CAM), Enterprise Resource Planning (ERP), Digital Mock-Up (DMU) and Product Data Management (PDM). Most construction industries are trying to apply these technologies for quality improvement, reduction of construction time and cost. PDM is very useful for managing data and process related to product design and manufacturing. PDM system has various functions such as drawing and engineering document management, product structure and structure modification management, part classification management, workflow management, and project management. In this paper, PDM system was applied to the design of steel-concrete composite girder bridge. To make a practical guidance for PDM implementation to bridge design, the procedure for its implementation was presented. Consequently, this paper could be useful to enhance the efficiency of bridge design.

• International Journal of Automotive Technology
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• 제8권3호
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• pp.383-394
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• 2007

Due to the clutch's non-linear dynamics, time-delays, external disturbance and parameter uncertainty, the automated clutch is difficult to control precisely during the launch process or automatic mechanical transmission (AMT) vehicles. In this paper, an enhanced fuzzy sliding mode controller (EFSMC) is proposed to control the automated clutch. The sliding and global stability conditions are formulated and analyzed in terms of the Lyapunov full quadratic form. The chattering phenomenon is handled by using a saturation function to replace the pure sign function and fuzzy logic adaptation system in the control law. To meet the real-time requirement of the automated clutch, the region-wise linear technology s adopted to reduce the fuzzy rules of the EFSMC. The simulation results have shown hat the proposed controller can achieve a higher performance with minimum reaching time and smooth control actions. In addition, our data also show that the controller is effective and robust to the parametric variation and external disturbance.

• 대한치과기공학회지
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• 제46권1호
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• pp.15-19
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• 2024

An ideal post material should have physical properties similar to those of dentin. Post materials with high elastic moduli may cause root fractures. This clinical report describes the treatment of a severely damaged tooth using a recently introduced material. Polyetherketoneketone (PEKK) is a semicrystalline high-performance thermoplastic polymer. PEKK is a promising material for custom post-and-core fabrication because of its elasticity close to that of dentin, good shock absorbance, machinability, and low cost. A laboratory scanner was used to digitize the conventional impression of a severely damaged maxillary right first molar. A custom PEKK post-and-core was designed and milled using computer-aided design and computer-aided manufacturing technology. Using the proposed technique, a custom PEKK post-and-core was fabricated accurately and human error was reduced. Restoration was luted with resin cement. Custom PEKK post-and-core restorations are a viable alternative for treating severely damaged teeth.

• 구강회복응용과학지
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• 제32권2호
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• pp.141-148
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• 2016

Computer-aided technology는 최근 치과 치료의 흐름이다. DENTCA$^{TM}$ CAD/CAM denture (DENTCA Inc.)는 상용화된 computer-aided design/computer-aided manufacturing (CAD/CAM) 의치 시스템 중 하나로, 한 번의 내원을 통해 의치 제작에 필요한 환자의 모든 정보를 획득하여, 이 정보를 컴퓨터에 저장하고 3D 프린팅을 통해 두 번째 내원 시에 의치 장착을 목표로 한다. 현재까지 여러 증례들은 총의치 제작에 대한 CAD/CAM system의 임상적 적용을 시험해 보았다. 본 증례는 두 명의 환자에서 DENTCA system을 이용한 의치와 전통적인 방법을 이용한 의치를 동시에 제작하여 DENTCA system의 효용성과 한계점을 고찰하였다.

• 대한치과기공학회지
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• 제43권4호
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• pp.202-209
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• 2021

By classifying temporary denture production for surgical guides, digital guide-based surgery, and final prosthesis production, the problems of each process were assessed in advance and the factors that could be improved were confirmed in this study. The manufacturing process of fusion dental prosthesis uses virtual programs and computed tomography images to manufacture devices using the latest technologies of computer-aided design/computer-aided manufacturing and three-dimensional printing, which enables implants to be placed in the desired location in advance. Moreover, implant placement is not dependent on the skill and condition of the dentist, and because it uses a computer system, it can always be performed at a constant and optimal position. This can reduce the remanufacturing rate compared with the general method, shorten the treatment period, and eliminate patient discomfort. Unlike the traditional method of using impression materials and plaster models, digital fusion dental prostheses would be evaluated as a technology for producing prosthesis through professional design technology and communication.