• 한국공작기계학회:학술대회논문집
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• 한국공작기계학회 2000년도 춘계학술대회논문집 - 한국공작기계학회
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• pp.435-440
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• 2000

In this study, we aims to develop the machining technology for the ultra precision surface and profile accuracy. For this purpose, we construct the electrolytic in process grinding system (ELID grinding) and apply to the cylindrical and internal grinding. Through the various machining experiments such as SCM steel., ceramics, tungsten carbide etc., we have obtained nanometer surface roughness. And we have applied this mirror grinding technique to hydraulic manual valve and mold core of mini disk optical pick-up base. For the development of fine mechanical part machining technology, e have made multi fiber optical connector using fine grinding technology. And constructed micro drilling system with process monitoring system which is possible to drill 50${\mu}{\textrm}{m}$ diameter hole.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2000년도 하계학술대회 논문집 C
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• pp.1557-1559
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• 2000

In this paper, we intend to establish the judgement of electrical fire through analysis of PT(Potential Transformer) using the power installation. The columnar structure and the void generated by abrupt heat grew at the tenter of boundary-face on the metallurgical microscope analysis. The detection of OK lines was confirmed by EDX(Energy Dispersive X-ray spectroscopy) as melting and recombination due to the layer-short of the wiring. We found that the thermal-weight decrease occurred at 300$^{\circ}C$ in case of being the thermal-deterioration on the base of the result that analyzed the insulated-materials by using TGA, and the thermal reaction limited-value of PT insulator was about 300$^{\circ}C$ on the DSC curve. As this analysis, we confirmed what the layer-short appeared in the wiring of PT.

• 한국반도체및디스플레이장비학회:학술대회논문집
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• 한국반도체및디스플레이장비학회 2002년도 추계학술대회 발표 논문집
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• pp.123-126
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• 2002

For the mold die sticking mechanism, the major explanation is that EMC filler of silica wears die surface roughened, which results in increase of adhesion strength. As big differences in experimental results from semiconductor manufacturers are dependent on EMC models, however, chemisorptions or acid-base interaction is apt to be also functioning as major mechanisms. In this investigation, the plasma source ion implantation (PSII) using $O_2$, $N_2$, and $CF_4$ modifies sample surface to form a new dense layer and improve surface hardness, and change metal surface condition from hydrophilic to hydrophobic and vice versa. Through surface energy quantification by measuring contact angle and surface ion coupling state analysis by Auger, major governing mechanism for sticking issue was figured out to be a complex of mechanical and chemical factors.

• 마이크로전자및패키징학회지
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• 제9권4호
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• pp.31-34
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• 2002

For the mold die sticking mechanism, the major explanation is that the silica as a filler in EMC (epoxy molding compound) wears die surface to be roughened, which results in increase of adhesion strength. As the sticking behavior, however, showed strong dependency on the EMC models based on the experimental results from different semiconductor manufacturers, chemisorption or acid-base interaction is apt to be also functioning as major mechanisms. In this investigation, the plasma source ion implantation (PSII) using $O_2, N_2$, and $CF_4$ modifies sample surface to form a new dense layer and improve surface hardness, and change metal surface condition from hydrophilic to hydrophobic or vice versa. Through surface energy quantification by measuring contact angle and surface ion coupling state analysis by Auger, major governing mechanism for sticking issue was figured out to be a complex of mechanical and chemical factors.

• 한국표면공학회지
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• 제36권1호
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• pp.48-58
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• 2003

This paper will present an overview of toxicity of hexavalent chromium as well as effort for its replacement by a wide spectrum of alternative materials and technologies. Cr-based materials such as trivalent electrodeposit will be one of strong candidates for hard chromium by surface modification of its surface hardness. Ni-base alloy deposits has proved its application in specific mold for glass. HVOF has been studied in aircraft and military sector. There are still under way of development for commercially available alternatives. To date, no single coating has been identified as universal process as comparable to conventional hard chromium electroplating.

• 한국정밀공학회:학술대회논문집
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• 한국정밀공학회 2005년도 추계학술대회 논문집
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• pp.777-780
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• 2005

The global consumption of aspheric surfaces will expand rapidly on the Electronics and Optical Components Information and Communications, Aerospace and Defense, and Medical optics markets etc. We must research on market, technology forecast and analysis of aspheric surfaces that is a principle step of ultra precision machine technology with a base one of optical elements. Especially, F-theta lens is one of the important parts in LSU(Laser scanning unit) because it affects on the optical performance of LSU dominantly. The core is most of important to produce plastic F-theta lens by plastic injection molding method, which is necessary to get the ultra-precision aspheric and non-axisymmetric machine processing technology.

• 한국정밀공학회지
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• 제21권7호
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• pp.145-152
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• 2004

This paper proposed efficient manufacturing system using the OMM (on-machine measurement) system. The OMM system is software based 3D modeler for inspection on machine and it is interfaced tool machine with RS232C. The software is composed of two inspection modules that one is touch probe operating module and the other is laser displacement sensor operating module. The module for touch probe has need of inspection feature that extracted it from CAD data. Touch probe moves to workpiece by three operating modes as follows: manual, general and automatic mode. The operating module of laser displacement sensor is used inspection for profile and very small hole. An Advantage of this inspection method is to be able to execute on-line inspection during machining or after it. The efficiency of proposed system which can predict and definite the machining errors of each process is verified, so the developed system is applied to inspect the mold-base(cavity, core).

• 대한소아치과학회지
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• 제44권3호
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• pp.335-340
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• 2017

복합 레진은 소아치과 영역에서 대중적으로 사용되는 재료가 되었다. 하지만 복합 레진은 중합 수축을 최소화하기 위하여 적층 충전을 해야 하기 때문에 긴 시술 시간이 필요하다. 이러한 문제를 극복하기 위하여 임상가들은 bulk-filling 재료에 관심을 돌리기 시작하였고, 최근 bulk-base 복합 레진이 새로 출시되었다. 본 연구는 bulk-base 복합 레진의 깊이별 미세경도 측정값을 비교, 평가하였다. 실험군으로 1종의 저점도 bulk-base 복합 레진과 1종의 고점도 bulk-base 복합 레진을 사용하였고 대조군으로 1종의 전통적 복합 레진을 사용하였다. 각 깊이별 재료들의 미세경도에 대한 결과로 대조군의 경우는 중합 깊이가 깊어질수록 미세경도의 유의한 차이를 보였다(p < 0.05). 이에 반해 실험군 인 HFB는 0 mm와 4 mm에서, 그리고 MFB는 0 mm와 2 mm, 0 mm와 3 mm에서 각각 유의한 차이를 보였으나 높이에 따른 유의한 감소 경향을 보이지는 않았다. 각각의 깊이에서 시편들의 미세경도를 비교하였을 때 표면과 2 mm에서는 대조군이 실험군보다 큰 미세경도를 보였다(p < 0.05). 3 mm에서는 저점도 실험군이 대조군보다 미세경도가 크게 나왔으나 통계적으로 유의한 차이는 아니었다. 하지만 4 mm에서는 모든 실험군이 대조군보다 통계적으로 유의하게 큰 미세경도 값을 보였다(p < 0.05). 이번 실험을 통하여 bulk-base 복합 레진이 4 mm에서 기존의 복합 레진보다 더 높은 미세경도를 보였고 표면과 2 mm에서는 더 낮은 미세경도를 보이는 것을 관찰하였다. 그러므로 bulk-base 레진의 기계적 성질의 향상을 통해 표면의 낮은 미세경도 특성이 극복된다면 소아 환자의 수복 치료 시 적용이 고려되어 질 만 할 것이다.

• 식물병연구
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• 제24권4호
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• pp.302-307
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• 2018

2014년부터 2016년까지 전라북도농업기술원(익산) 시험연구포장에 식재한 오크라에서 잿빛곰팡이병이 5%정도 발생하였다. 초기 감염은 열매의 기저부에서 갈색 또는 회색의 점무늬로부터 시작하여 꼬투리와 줄기 쪽으로 확대되었고, 수침상으로 분생포자와 함께 많은 균사가 형성되다. 감자한천배지에서 균사 생육은 직경이 65-80 mm/7일이었으며, 중앙부와 가장자리에서 진한 쥐색으로 양모상이었다. 2주간 배양된 병원균은 배지 위에 작고 검은색의 균핵을 형성하였으며, 크기는 $1.0-3.5{\times}0.5-3.0mm$이었다. 병원균의 분생포자는 무색 또는 회색의 단세포이며, 구형 또는 타원형으로 크기는 $6.2-15.4{\times}5.0-10.4{\mu}m$이었다. 또한 수지상으로 분지한 분생포자경위에 포도 송이와 같이 분생포자가 집단적으로 형성되었다. 분생포자경은 갈색 또는 투명한 색의 수지상으로 크기는 $85-450{\times}10.0-40.0{\mu}m$이었다. 균학적 특징, 병원성 검정, ITS rDNA 염기서열 비교분석 등의 결과를 바탕으로 이 병은 우리나라에서 지금까지 보고되지 않은 Botrytis cinerea Pers.에 의한 오크라 잿빛곰팡이병으로 명명하고자 한다.

• 구강회복응용과학지
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• 제17권2호
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• pp.107-112
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• 2001

The prosthodontic treatment of severely resorbed edentulous patients has been one of the frustrating areas due to extensive loss of tissues. The integrated neuromuscular balance among tongue, lip, and cheek is compromised. The retention, stability, and support are the three major factors to influence the clinical outcome. Fish described a denture as having three surface, with each surface playing an independent and important role in the over all fit, stability, and comfort of the denture. He recommended that the polished surface should be a series of inclines so that pressure from muscular activity will retain dentures. Within the denture space there is an area that has been termed the neutral zone. The neutral zone is that area in the mouth where, during function, the forces of the tongue pressing outward are neutralized by the forces of the cheeks and lips pressing inward. According to Jacobson and Krol, neuromuscular control interacts to provide retention and the relationship of polished surface of denture base to the surrounding muscular structure of orofacial capsule facilitates the stability and retention. This neutral zone concept has been demonstrated with various modification by a number of authors. The theory used to develop the denture base contours is based on the belief that the muscle should functionally mold not only the border but the entire polished surface. Lott and Walsh reported the clinical success on complete mandibular dentures with application of neutral zone concept. A number of studies demonstrated that denture stability and retention are more dependent on correct position of the teeth and correct contour of external surfaces of the denture in a severely resorbed alveolar ridge. This article presents a prosthodontic approach to treatment of a edentulous patient using neutral zone technique to improve the retention and stability of the prosthesis.