• Proceedings of the KSR Conference
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• 2003.05a
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• pp.712-717
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• 2003

지능 재료를 이용한 디바이스는 자연계에 존재하는 생명체와 같이 내.외부 환경 변화에 대응하여 스스로 변하는 능동적 기능을 갖고 있기 때문에 시스템 성능의 극대화 및 유지비용의 최소화를 가져오게 된다. 이러한 지능재료 기술은 지난 10여년 전부터 연구되었는데 대표적인 웅용을 보면, 산업, 항공, 교통, 운송 분야의 능동 소음 및 반능동 진동제어; 복합 재료 손상위치 탐지시스템, 손상구조 건전성 평가시스템, 교량, 저장탱크, 건물, 유조선, 대형 구조물의 건전성 평가 시스템; 초정밀 직진 안내기구, 나노 스테이지, 절삭오차 보정용 엑츄에이터, 초음파 회전모터, 지능유압 서보밸브, 변형 거울 등의 모터/엑츄에이터; 자동차 엔진 성능제어, 흡배기구 압력측정, 가속도 센서, 자이로센서, 에어백 센서, 타이어 센서 등의 지능 MEMS/NEMS 센서; electronic article 정찰, 도서태그, 비접촉 항공 운송물 분류 및 보안시스템, 전자 운전자 식별시스템, 광섬유 건물 보안 시스템, 지능 신경망 형상 인식 시스템 등의 보안 시스템; 지능항공기 구조물, 인공위성안테나, 헬리콥터 회전익 등의 형상제어가 있다. 본 논문에서는 지능재료 기술을 정리하고 차세대 철도차량 기술에 지금까지 적용한 예를 소개하며 향후 적용할 수 있는 분야들을 가능성 및 실용성 면에서 소개하고자 한다.

• Journal of the Korean Society for Precision Engineering
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• v.20 no.6
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• pp.20-26
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• 2003

This study proposes the construction of attractor quadrant method for high-precision cutting characteristics evaluation of non-ferrous metals. Also this paper aims to find the optimal cutting conditions of diamond turning machine by measuring surface form and roughness to perform the cutting experiment of non-ferrous metals, which are aluminum, with diamond tool. As well, according to change cutting conditions such as feed rate, using diamond turning machine to Perform cutting Processing, by measuring cutting force and surface roughness and according to cutting conditions the aluminum about cutting properties. Trajectory changes in the attractor indicated a substantial difference in fractal characteristics and attractor quadrant characteristics. In quantitative quadrant feature extraction, 1,309 point in the case of A17075 (one quadrant) and 1,406 point (one quadrant) in the case of brass were proposed on the basis of attractor reconstruction. Proposed attractor quadrant method can be used for high-precision cutting characteristics evaluation of non-ferrous metals.

• Journal of Practical Engineering Education
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• v.15 no.1
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• pp.119-126
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• 2023

Today, in order to improve fuel efficiency and dynamic behavior of automobiles, an era of light weight and simplification of automobile parts is being formed. In order to simplify and design and manufacture the shape of the product, various components are integrated. For example, in order to commercialize three products into one product, product processing is occurring to a very narrow area. In the case of existing parts, precision die casting or casting production is used for processing convenience, and the multi-piece method requires a lot of processes and reduces the precision and strength of the parts. It is very advantageous to manufacture integrally to simplify the processing air and secure the strength of the parts, but if a deep and narrow pocket part needs to be processed, it cannot be processed with the equipment's own spindle. To solve a problem, research on cutting processing is being actively conducted, and multi-axis composite processing technology not only solves this problem. It has many advantages, such as being able to cut into composite shapes that have been difficult to flexibly cut through various processes with one machine tool so far. However, the reality is that expensive equipment increases manufacturing costs and lacks engineers who can operate the machine. In the five-axis cutting processing machine, when producing products with deep and narrow sections, the cycle time increases in product production due to the indirectness of tools, and many problems occur in processing. Therefore, dedicated machine tools and multi-axis composite machines should be used. Alternatively, an angle spindle may be used as a special tool capable of multi-axis composite machining of five or more axes in a three-axis machining center. Various and continuous studies are needed in areas such as processing vibration absorption, low heat generation and operational stability, excellent dimensional stability, and strength securing by using the angle spindle.

• Journal of Dental Rehabilitation and Applied Science
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• v.38 no.3
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• pp.127-137
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• 2022

Zirconia is fabricated through various processes. Each element in fabricating process can affect the physical properties of the definitive prosthesis. In particular, both the milling process and the sintering process can affect the final integrity of the zirconia prosthesis. Most of the milling machines adopt the ultra-precision 5-axis machining method, and the results vary depending on which milling method was used and how the milling equipment was managed. Milling blocks are selected according to cutting efficiency and aesthetic reproducibility. The sintering method can affect the grain growth and optical properties, and an accurate evaluation can be made only with additional research on the recent speed sintering procedure. Not only the sintering temperature but also the temperature holding time can affect the quality of definitive prosthesis.