• 대한기계학회:학술대회논문집
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• 대한기계학회 2001년도 춘계학술대회논문집C
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• pp.152-157
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• 2001

This paper is to model a 3D-shape product applying mathematically the data acquired from a 30 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 sol id 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 30 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 CDA-based program automatically. Utilization of this program make it possible to minimize time in designing a product and establish a ADS(Automatic design system) program library to using all of the data from reverse engineering.

• 한국기계가공학회지
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• 제6권4호
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• pp.36-43
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• 2007

Dieless CNC forming is an innovative technology which can form various materials with complex shape by numerically controlled incremental forming process. In order to apply the technology to industrial parts, however, many problems such as spring-back, rising of material, and trimming difficulty must be solved. In this paper a new dieless CNC forming method to improve forming quality is proposed, which consists of how to modify its original shape in CAD and how to generate its CNC tool path in CAM. The effectiveness of the proposed procedures is tested with a brake dust shield of a vehicle. The results shows that the method proposed enhances the forming quality up to 48% compared to traditional method.

• 대한치과보철학회지
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• 제54권3호
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• pp.234-238
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• 2016

목적: 최근 치과 영역에서 CAD-CAM (computer aided design-computer aided manufacturer) 시스템의 이용과 디자인 소프트웨어가 늘어남에 따라 쉽고 빠른 수복물의 디자인이 가능해졌다. 과거에는 치과 기공사의 wax up 기술의 숙련도에 따라 금관의 외형이 결정 되었으나, CAD-CAM 시스템에서는 디자인 소프트웨어에 대한 숙련도가 더 중요한 요인이 되어가고 있다. 이에 치과 기공사와 치과의사간의 결과물의 차이를 알아보고자 한다. 재료 및 방법: 대합치와 인접치가 양호한 환자의 하악 우측 제1대구치를 금관 지대치 형성 한 후 polyether로 인상채득 하였다. 인상재에 초경석고를 이용하여 모형을 제작 하였으며, Trios 구강내 스캐너를 이용하여 STL (stereolithography) 파일을 추출하였다. 3shape dental designer 상에서 5년 이상 경력의 치과 기공사 1명, 2년 이하 경력의 치과 기공사 3명, 4명의 보철과 1년차 전공의가 동일한 STL 파일을 이용하여 금관을 디자인 하였다. CAD-CAM 시스템 경력이 가장 오래된 기공사의 디자인을 기준으로 하여 치과 기공사 그룹 3명(group DT)과 1년차 전공의 그룹 4명(group RT) 의 금관 외형을 비교하였다. 디자인된 금관의 근원심폭, 협설폭, 높이, 교두간 거리, 대합치와의 접촉점의 수를 측정, 비교 하였다. 독립표본 t검정을 시행하여 그룹간의 차이를 비교하였고, 대합치와의 접촉점의 수는 Wilcoxon signed-rank test 를 이용하였다. 결과: 정규성 검정 결과 근원심폭, 협설폭, 높이, 교두간 거리는 정규분포를 보였다. Group DT와 group RT의 금관 디자인상에서 근원심폭, 협설폭, 높이, 교두간 거리에서 통계적으로 유의할만한 차이가 없었다. 대합치와의 접촉점 수는 정규분포를 보이지 않았으며, wilcoxon signed-rank test 결과 통계적으로 유의한 차이를 보이지 않았다. 결론: 금관의 외형의 크기에 있어서는 group DT와 group RT 사이에 통계학적으로 유의할만한 차이가 없었지만 수치화하기 어려운 금관의 해부학적 형태나 주변 치아와의 형태적 유사성 등은 차이가 있었다. 디자인 소프트웨어에 대한 숙련도가 높아진다면 각 술자가 가지고 있는 교합에 대한 개념을 더 구현하기 쉬울 것이다.

• 대한치과의사협회지
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• 제57권9호
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• pp.524-528
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• 2019

With the advances of CAD-CAM (computer-aided design and computer-aided manufacturing) technology, the field of modern clinical dentistry has been dramatically changed. The first step in the digital workflow for tooth-supported dental prosthesis is a data acquisition with intraoral digital or conventional impression techniques. For the accuracy of intraoral digital impression data, the basic principles of conventional impression should be applied. It is necessary to obtain a good visibility with properly-dried field and well-exposed margin of the prepared abutment. Currently, the equi- or supra-gingival finish line can be recommended as an indication for intraoral digital impression. The scan data are generally exported to '.stl' file format, which has only morphological information of black and whitem while '.obj' file format can store data on color and texture.

• 한국CDE학회논문집
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• 제8권3호
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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.

• 대한치과보철학회지
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• 제57권4호
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• pp.456-466
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• 2019

최근 디지털 치의학 기술이 치과 치료에 다양하게 활용이 되고 있다. 본 증례는 다수의 치아 상실과 치아 마모로 수직고경이 감소한 환자의 치료에서 이러한 디지털 치의학 기술이 어떻게 적용되는지 다루고 있다. 감소한 수직고경을 주의 깊게 평가하여 회복하였고, 최종 수복물을 고려하여 설계한 수술용 가이드를 이용하여 임플란트 식립을 시행하였다. 디지털 악간관계 측정기를 이용하여 하악의 전측방 운동을 측정하여 교합기에 반영하였고, Naturgemäße Aufwachs-Technik (N.A.T.), Natural functional reconstruction (N.F.R.)을 이용한 왁스업 과정을 진행하였다. 이를 스캔하여 CAD/CAM 기술로 임시 수복물을 제작하였고, 기능적, 심미적으로 만족스러운 상태까지 진료실에서 조정과정을 거친 뒤 Computer-Aided-Design/Computer-Aided-Manufacturing (CAD/CAM) 기술을 활용하여 최종 수복물로 그대로 이행될 수 있도록 하였다. 이와 같이 디지털 치의학 기술과 전통적인 방식의 장점을 활용하여 환자와 술자 모두 만족할만한 결과를 얻었기에 이를 보고하고자 한다.

• The Journal of Advanced Prosthodontics
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• 제11권6호
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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.

• 한국공작기계학회논문집
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• 제11권1호
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• pp.91-96
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• 2002

Recently industry has moved towards automated operations with the goal of achieving better product quality greater productivity and reliability The pump design in characterized by extensive utilization of the related database which contains performance data. The inputs to the system are through interactive dialogue sessions and the basic input consist of flow rate, head, of fluid efficiency and the customer special requirements. These basic inputs along with the numerous rules in the knowledge bases and the mathematical modeling enable the effective design of the pump industry This paper represents the development of an automatic pump design system that was composed of a main program the data input module the drawing module the drawing edit module and was programed by the AutoLISP language under the Auto CAD program The developed system ultimately generates the design for a pump through the AutoCAD language.

• 한국소성가공학회:학술대회논문집
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• 한국소성가공학회 1997년도 추계학술대회논문집
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• pp.168-171
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• 1997

With the development of computers, CAD(Computer-Aided-Design)/CAM (Computer-Aided-Manufacturing) has been increasingly applied to manufacturing processes to increase productivity, and recently studies of expert systems, a field of Al(Artificial Intelligence), are being carried out to assist process designs. In this study, an expert system for the process design of ball stud was developed. The adequacy of the developed system was examined through comparisons with actual blueprints and verification by experts. The designed process data was saved in dxf file format for transfer to AutoCAD, from which prototype process blueprints were obtained.

• The Journal of Advanced Prosthodontics
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• 제12권6호
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• pp.376-382
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• 2020

PURPOSE. To determine the shear bond strengths of different denture base resins to different types of prefabricated teeth (acrylic, nanohybrid composite, and cross-linked) and denture teeth produced by computer-aided design/computer-aided manufacturing (CAD/CAM) technology. MATERIALS AND METHODS. Prefabricated teeth and CAD/CAM (milled) denture teeth were divided into 10 groups and bonded to different denture base materials. Groups 1-3 comprised of different types of prefabricated teeth and cold-polymerized denture base resin; groups 4-6 comprised of different types of prefabricated teeth and heat-polymerized denture base resin; groups 7-9 comprised of different types of prefabricated teeth and CAD/CAM (milled) denture base resin; and group 10 comprised of milled denture teeth produced by CAD/CAM technology and CAD/CAM (milled) denture base resin. A universal testing machine was used to evaluate the shear bond strength for all specimens. One-way ANOVA and Tukey post-hoc test were used for analyzing the data (α=.05). RESULTS. The shear bond strengths of different groups ranged from 3.37 ± 2.14 MPa to 18.10 ± 2.68 MPa. Statistical analysis showed significant differences among the tested groups (P<.0001). Among different polymerization methods, the lowest values were determined in cold-polymerized resin.There was no significant difference between the shear bond strength values of heat-polymerized and CAD/CAM (milled) denture base resins. CONCLUSION. Different combinations of materials for removable denture base and denture teeth can affect their bond strength. Cold-polymerized resin should be avoided for attaching prefabricated teeth to a denture base. CAD/CAM (milled) and heat-polymerized denture base resins bonded to different types of prefabricated teeth show similar shear bond strength values.