• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2004년도 ICCAS
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• pp.716-721
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• 2004

Several Solid Freeform Fabrication Systems(SFFS) are commercialized in a few companies for rapid prototyping. However, they have many technical problems including the limitation of applicable materials. A new method of speedy prototyping is required for the recent manufacturing environments of multi-item and small quantity production. The objectives of this paper include the development of a novel method of SFFS, the ${CAFL}^{VM}$(Computer Aided Fabrication of Lamination for Various Material), and the manufacture of the various material samples for the certification of the proposed system and the creation of new application areas. For these objectives, the technologies for a highly accurate robot path control, the optimization of support structure, CAD modeling, adaptive slicing was implemented. In this paper, we design an algorithm that the cutting path of a laser beam which is controlled with constant speed. The laser beam is tangentially controlled in order to solve the inaccuracy of a 3D model surface. The designed algorithm for constant-speed path control and tangent-cutting control is implemented and experimented in the ${CAFL}^{VM}$ system.

• 전자공학회논문지SC
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• 제42권1호
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• pp.1-11
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• 2005

본 연구에서는 다양한 재료의 시트(Sheet)를 각각 절단하여 적층하는 방법으로 기존 적층조형법과는 다른 쾌속 임의형상제작 시스템인 CAFL/sup VM/(Computer Aided Fabrication of Lamination for Various Material)을 제안한다. 이러한 조형 방법은 가공 속도를 빠르게 하며 복잡한 후처리 과정을윽 대폭 줄일 수 있고, 여러 가지 재료가 사용 가능한 장점을 지니고 있다. 이러한 목적으로 개발된 2자유도의 X-Y테이블 형태의 CAFL/sup VM/은 레이저빔으로 시트(Sheet)를 절단, 적층하여 조형물을 완성하는 새로운 고속적층 시스템으로 가능성을 검증하였다. 하지만 2자유도 시스템은 X-Y 평면을 이동하는 작업공간에 수직으로 레이저 가공이 이루어지는 방법으로, 조형된 사물의 표면에 계단 형상이 나타나는 표면정밀도상의 문제점을 드러낸다. 이러한 문제점을 해결하고자 2자유도에 3자유도를 추가한 5자유도 시스템을 제안하여 레이저의 경사절단이 가능하게 함으로서 조형된 사물의 표면 정밀도를 높이고, 일정한 패턴의 모양을 갖는 조형물 가공의 경우 여러 시트(Sheet)가 적층되는 부분을 한번에 가공할 수 있도록 하여 보다 빠르고 정밀한 5자유도 매니퓰레이터 CAFL/sup VM/ 시스템을 설계한다. 즉, 정속경로제어와 경사각절단제어를 구현하고 그 외에 수반된 자동화 CAFL/sup VM/ 시스템을 구현하는 것이 본 논문의 목적이다.

• Restorative Dentistry and Endodontics
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• 제12권1호
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• pp.131-147
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• 1986

The purpose of this study was to observe the color matching of lining or filling materials according to the remaining tooth material. Twenty-seven freshly extracted human central incisors were used in this experiments. The teeth were stored in saline solution at room temperature after extraction. All teeth were cut parallel to the tangent to height of contour on labial surface from the lingual surface until the pulp were completely removed. Then 27 teeth were devided into 0.5mm, 1.0mm and 1.5mm reduction groups according to the thickness of cutting the lingual surfaces of teeth. The specimens of control group were three teeth of 27 teeth with cutting the lingual surface same mode as above described. In the specimens of experimental groups, 8 kinds of lining and filling materials; FUJI IONOMER TYPE II (G-C Co. Japan), LINING CEMENT (G-C Co. Japan), Dycal (Caulk, U.S.A.), CLEARFIL F II (Kuraray Co. Japan), Crown Bridge & Inlay Cement (G-C Co. Japan), Copalite (Harry J. Bosworth Co. U.S.A.), HY-BOND (G-C Co. Japan) and LIV-CENERA (G-C Co. Japan); applied on the back of 24 teeth with 0.5mm, 1.0mm and 1.5mm cut thickness of lingual surfaces. Three teeth of control group did not applied linging or filling materials on the back of 3 kinds of different thickness of cutting the lingual surfaces. The absorbances of total 27 specimens were obtained by reflection spectrophotometer. (Cary 17 D, Varian Co, U.S.A.) The following conclusions were drawn from above the results; 1. The absorbance patterns in both experiment and control groups were gradually decreased with increasing wavelength of spectra. 2. The absorbance patterns were not decreased in relation to the kinds of lining or filling materials, but the amount of the remaining tooth materials. 3. In 0.5mm reduction group, FUJI IONOMER TYPE II, LINING CEMENT, LIV-CENERA and Copalite applied on the back of cut lingual surface showed similar absorbance patterns as control group. 4. The specimens which were reduced up to 1.0mm thickness and lined with FUJI IONOMER TYPE II and LINING CEMENT showed the comparable absorbance patterns to the control group. 5. In case of HY-BOND application after 1.5mm reduction were observed the similar absorbance pattern as compared with control group. 6. When Dycal, CLEARFIL and Crown Bridge & Inlay Cement were applied to cut teeth surfaces, there were much differences of absorbance between control groups and experimental groups.