• The Journal of Korean Academy of Prosthodontics
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• v.59 no.3
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• pp.370-378
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• 2021

Purpose. The purpose of this study was to evaluate the currently published literatures investigating the accuracy of computer-aided design and computer-aided manufacturing removable partial denture (CAD-CAM RPD) framework with different manufacturing techniques and methods. Materials and methods. A comprehensive search for literatures was conducted in PubMed database using specific keywords with the patient, intervention, comparison, and outcome (PICO) question, "Is there a difference in accuracy of RPD frameworks manufactured using digital workflow according to the manufacturing process and methods?" Results. A total of 7 articles were selected. Two studies compared intraoral scanning and laboratory scanning for RPD frameworks and had heterogenous results. In the studies using different manufacturing process, RPD frameworks had clinically acceptable accuracy in both subtractive and additive manufacturing. Polyetheretherketone (PEEK)-milled RPD frameworks showed higher fit accuracy than traditionally casted or 3D printed RPDs. Direct milling method showed a higher accuracy than indirect milling method. However, in rapid prototyping, indirect method showed higher accuracy than direct method. Conclusion. The RPD frameworks fabricated using CAD-CAM technology showed a clinically acceptable level of accuracy regardless of manufacturing process or techniques. Consistent results have not been reported regarding the digital impression methods, which were intra oral scanning or laboratory scanning, and further studies are needed.

• Korean Journal of Computational Design and Engineering
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• v.8 no.3
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• pp.157-166
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• 2003

In this paper, we explain the DMU (digital mockup) system based on the PDM system. Most manufacturing companies are trying to develop a competitive product by increasing the quality, shortening time to market (TIM) and reducing the cost of a product. Some technologies such as SE (System Engineering), CE (Concurrent Engineering), QFD (Quality Function Development), CI (Cost Innovation) and some systems such as CAD (Computer-Aided Design), CAE (Computer-Aided Engineering), CAM (Computer-Aided Manufacturing), PDM (Product Data Management) and visualization system are adopted for these purposes. Specially, DMU system utilizes a visualization system that shows the 3D shape of a product on the computer and it gives a quick intuition to a person whether he/she is an engineer or not. It also can induce the effects of CE and QFD. SO, 0 company is developing a DMU system integrating CAD, visualization and PDM system. The main feature of the developed DMU system is that it is entirely integrated with PDM system, which means that the 3D shape of any part or assembly can be retrieved through PDM system. The DMU system will change the development process, which will increase the competitiveness of a developed product.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2001.04a
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• pp.387-392
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• 2001

This paper is to model a 30-shape product applying mathematically the data acquired from a 3D scanner and using an Automatic Design Program. The research studied in th reverse engineering up to now has been developed continuously and surprisingly. However, forming 3D-shape solid models in CAE and CAM, based on the research, the study leaves much to be desired. Especially, analyses and studies reverse-designing automatically using measured data after manufacturing. Consequently, we are going to acquire geometric data using an 3D scanner in this study with which we will open a new field of reverse engineering by a program which can design a 3D-shape solid model in a CAD-based program automatically.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2006.05a
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• pp.623-624
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• 2006

Over the past decade, changes in product development processes and increased consumer demands have dramatically influenced engineering working practices and targets. The information technology revolution has made its appearance concurrent to this relentless escalation in product engineering requirement. It has offered hopes for improved productivity despite these increasing demands. The wide availability of personal computing power, virtually inexhaustible sources of information and an abundance of computerized engineering tools have created great expectations. CAPP (Computer Aided Process Planning) Expert system and database were developed using VB.NET and Microsoft SQL 2000 Server.

• Journal of Korean Institute of Industrial Engineers
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• v.17 no.2
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• pp.63-74
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• 1991

An expert scheduling system on real time basis for computer-aided manufacturing systems has been developed. In developing expert scheduling system, the most time-consuming job is to obtain rules from expert schedulers. An efficient process of obtaining rules directly form the schedules produced by expert schedulers is proposed. By the process, a set of complete and minimal set of rules is obtained. During a real time scheduling, when given information on possible values of elements, the rules produce possible values of decision elements, where logical explanations of the result may be offered in terms of chaining rules. The learning and scheduling processes have been simulated with an automated manufacturing line engaged in the production of circuit boards.

• 유체기계공업학회:학술대회논문집
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• 1999.12a
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• pp.333-337
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• 1999

The biggest challenge facing today manufacturing industry is better quality and high productivity. From an economic point of view, productivity is the most important parameter, as high productivity will reduce the cost. However, the customers of day are not only cost concerned, but also quality conscious. So high accuracy levels should also be achieved in the manufacturing process. This paper reports the development of a automatic design system based on AutoCAD program. 1'his work is composed of three section that are design of top down menu, impeller and casing for pump programed by AutoLISP language and runned Windows system. The developed system ultimately generates the design for a pump through AutoCAD program. In the design of the pump, it needs about 23 hours with an expert, but this system can be only 80 seconds without an expert.

• Journal of Dental Rehabilitation and Applied Science
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• v.36 no.2
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• pp.128-137
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• 2020

Over the last 30 years, the use of chairside computer-aided design (CAD) and computer-aided manufacturing (CAM) systems has evolved and has become increasingly popular in dentistry. Although CAD/CAM restorations have been used in the anterior dentition, satisfying the esthetic requirements of clinicians and patients, where the restorations are limited to the chairside, remains a challenge. To reproduce multi-shades of CAD/CAM restorations in the clinic, a preliminary experiment to express several shades on A2 lithium disilicate (LS2) blocks using a staining kit was performed. After measurement of the CIE L^*a^*b^* value of specimens, it was compared with that of the commercial shade guide. This report presents two cases with individual customization of shade and surface characterization of the CAD/CAM restorations using predictable methods based on the preliminary experimental data. The anatomical shape of restoration was obtained from 'copy and paste technique' and 'mirror image acquisition technique'. All treatment procedures and fabrication of restorations performed in this report were executed in the clinic itself.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.410-418
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• 2017

Amelogenesis imperfecta characterized as abnormally formed enamel is caused by a defect of unique group of genes. Patients affected by this disease might have difficulties in social and psychological aspects due to non-esthetic teeth as well as functional problems caused by enamel detachment and tooth wear from their early ages. Adult patients with amelogenesis imperfecta can be treated with full-mouth restorations, which make functional and esthetic rehabilitations of severely worn tooth. However, the anterior open bite and lack of occlusal clearance for posterior teeth restorations due to compensatory extrusion are the intervening factors in the prosthetic treatment. Therefore, the determination of anterior tooth lengths, vertical dimension, and anterior guidance should be set carefully. Recently, computer-aided design and computer-aided manufacturing (CAD/CAM) techniques help systematic approaches and enable dentists to reduce time-consuming procedures in the diagnosis and treatment of full-mouth rehabilitation. This case report demonstrates the successful full mouth rehabilitation using a CAD/CAM system in a young adult patient with amelogenesis imperfecta and anterior open bite.

• The Journal of Korean Academy of Prosthodontics
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• v.55 no.4
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• pp.427-435
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• 2017

The most important factor in the treatment of fully edentulous patients using implants is the shape of the definitive prosthesis. After the shape of the definitive prosthesis is determined, residual bone analysis and selection of the implant type, number and position should be followed. In this case, for restoration of an edentulous patient fully implanted (except the maxillary right lateral incisor) without considering definitive prosthesis, facial esthetics and possibility of fixed type prosthesis were evaluated using complete denture. It was determined that the fixed type prosthesis was possible. Implants that could not be used for the definitive prosthesis were excluded from the treatment plan and fixed type provisional restorations were fabricated. After four months of provisional restorations, the patient showed stable occlusion and esthetic satisfaction. Definitive prosthesis was made of zirconia using CAD/CAM (computer aided design and computer aided manufacturing). The results were satisfactory during the 3 months of follow-up period after termination of treatment.

• Journal of Engineering Education Research
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• v.11 no.1
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• pp.85-100
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• 2008

The purpose of this study is development of 'F1 in Schools Program' for elementary school student and validation of the program. Fifteen students were originally chosen from the W elementary school in Cheongju, Chungcheogbuk-Do. The children were tested on their understanding of science and 'F1 in Schools Program'. After developing the 'F1 in Schools Program', it was used in the classroom to evaluate applicability and to examine the responses from students, parents and schools. The program consists of 60 classes and the time of each class is 40 minutes. This study was conducted for 10 days from January 22nd, 2007 to February 2nd, 2007. CAD(Computer Aided Design), CFD(Computation Fluid Dynamics), CAM(Computer Aided manufacturing) and CNC Machine were used in this study and proved to be good materials for students in that they increased the students' participation and imagination. However, the children's cognitive and creative abilities as well as manuals written in English hampered the process. Most students, parents, schools seemed to be satisfied with use of the program. However, the schools showed that there was not enough understanding of the program as a whole. The processes with which students build and inspect using the $CO_2$Model Car not only improves the processing of the model but also enhanced the students scientific understanding related to the car speed.