• 고무기술
• /
• 제12권1호
• /
• pp.1-7
• /
• 2011

Nanotechnology is the fast becoming key technology of the $21^{st}$ century. Due to its fascinating size-dependent properties, it has gained significant important in various sectors. Myths are being formed on the proverbal nanotechnology market, but the reality is the nanotechnology is not a market but a value chain. The chain comprises of - nanomaterials (nanoparticles) and nanointermediates (coatings, compounds, smart fabrics). Elastomer based nanocomposites reinforced with low volume fraction of nanofillers is the first generation nanotechnology products and it has attracted great interest due to their fascinating properties. The incorporation of nanofillers such as nanolayered silicates, carbon nanotubes, nanofibers, metal oxides or silica nanoparticles into elastomers improves significantly their mechanical, thermal, barrier properties, flame retardency etc., Extremely small particle size, high aspect ratio and large interface area yield an excellent improvement of the properties in a wide variety of the materials. Uniform dispersion of the nanofillers is a general prerequisite for achieving desired properties. In this paper, current developments in the area of elastomer based nanocomposites reinforced with layered silicate and carbon nanotube fillers are highlighted.

• 소성∙가공
• /
• 제15권1호
• /
• pp.71-75
• /
• 2006

In recent, various shapes of pattern in micron or nano scale are adapted in many applications due to their good mechanical or optical properties. Light guide panel (LGP) of the LCD is one of important applications for micro pattern and micro prism shape is one of the typical patterns. The size of the surface patterns in most applications is decreasing to the order of micron or even under micron. On the other hand, the area to be patterned keeps enlarging. These two trends in patterned products require tooling micro patterns on large surface, which has still many technical problems to be solved mainly due to pattern size and the tooling area. In this study, we fabricated prism shape of patterns using diamond cutting tool on some metal core and plastic core like PMMA. Some cutting conditions were investigated including cutting force, cutting depth and speed for different core materials.

• JSTS:Journal of Semiconductor Technology and Science
• /
• 제7권1호
• /
• pp.43-50
• /
• 2007

In a high-speed flash style or a pipelining style analog-to-digital converter (A/D converter), the DC reference fluctuation caused by external noises becomes serious, as the sampling frequency is increased. To reduce the fluctuations in conventional A/D converters, capacitors have been simply used, but the layout area was large. Instead of capacitors, a low-noise and small-size DC reference circuit based on transmission gate (TG) is proposed in this paper. In order to verify the proposed technique, we designed and manufactured a 6-bit 2GSPS CMOS A/D converter. The A/D converter is designed with a 0.18um 1-poly 6-metal n-well CMOS technology, and it consumes 145mW at 1.8V power supply. It occupies the chip area of 977um by 1040um. The measured result shows that SNDR is 36.25 dB and INL/DNL is within 0.5LSB, even though the DC reference fluctuation is serious.

• Journal of Korean Vacuum Science & Technology
• /
• 제3권1호
• /
• pp.10-15
• /
• 1999

Using micro-wells on the Mo substrate, we could obtain various tubular-volcano-types of free-standing diamond field emitters by depositing a diamond film detaching the film and turning the film upside down. The field emission characteristics of these structures were investigated as a function of size, shape and the number density of the tubular-volcano-type diamond field emitters. The field emission characteristics, especially the current density, were greatly enhanced with increasing the number density of the tubular-volcano-type diamond field emitters on the Mo substrate. Based on these results, we suggest that the reduction of the well size can give better field emission characteristics by the increase in the number density of the tubular-volcano-type diamond field emitters. Finally, we suggest the feasibility of fabricating a large-area field emission display using our patterned tubular-volcano-type free-standing diamond field emitters.

• 한국소성가공학회:학술대회논문집
• /
• 한국소성가공학회 2005년도 금형가공,미세가공,플라스틱가공 공동 심포지엄
• /
• pp.110-113
• /
• 2005

In recent, various shapes of pattern in micron or nano scale are adapted in many applications due to their good mechanical or optical properties. Light guide panel (LGP) of the LCD is one of important applications for micro pattern and micro prism shape is one of the typical patterns. Many applications have the patterns on their surface and the size of the pattern keep decreasing down to the order of micron or even under micron. On the other hand, the area to be patterned keeps enlarging. These two trends in patterned products require tooling micro patterns on large surface, which has still many technical problems to be solved mainly due to pattern size and the tooling area. In this study, we fabricate prism shape of patterns using diamond cutting tool on some metal core and plastic core like PMMA Some of cutting conditions are investigated including cutting force, cutting depth and speed for different core materials.

• 한국식품조리과학회지
• /
• 제13권3호
• /
• pp.314-318
• /
• 1997

This study was conducted over eat-nut foods in Andong area to measure the salt concentration and to compare the result with the optimum gustation of salt concentration in usual diets. The results were as follows: 1. Mean salt concentration of eat-nut foods was similar to the optimum salt concentration by sensory evaluation. 2. The salt intake through the menu was about twice of the recommended intake by Korean Food Research. 3. The foods with a large serving size contributed to the increase of salt intake, suggesting that the serving size needs to be adjusted. 4. It is recommended that the consumption of high salt foods needs to be reduced while increasing that of fresh fruit and vegetable in the diet behavior on eat-out foods.

• 한국기계가공학회지
• /
• 제18권1호
• /
• pp.9-15
• /
• 2019

This study focused on the application of ELID mirror-surface grinding technology to the manufacture of off-axis asymmetric large-area reflecting mirrors made of BK7 glass. The size of the parts, such as asymmetric large-area mirrors or lens, made form-accuracy or roughness especially hard to measure after machining because of the measuring range limit of measurement devices. In this study, the ELID grinding system has been set up for mirror-surface machining experiments manufacturing off-axis asymmetric lenses. A measuring method using a reference workpiece has been suggested to measure the form-accuracy and roughness. According to the experimental results, even when using only a reference workpiece, it is confirmed that the surface roughness was 8 nmRa and form-accuracy was 80 nmRMS, with a best fit asymmetric radius when using a grinding wheel of #8,000. It is found that the accuracy of large-area parts could be estimated by the proposed process.

• 교육시설
• /
• 제10권5호
• /
• pp.5-14
• /
• 2003

The purpose of this survey study is to analyse the playground dimension of elementary school. To complete this mission, it is necessary to drive out elementary school have a lower dimension standard of playground through literal survey. Then, questionnaire and observation survey have been performed to teachers majored in physical education and these are focused on playground dimensions. The field survey study will provide the basic data for calculating proper playground dimensions and design source for planning space program of the school. The result of this survey study are as follows ; First, The Area of 'Gyo-ghi' is decreasing, and the land area of being used for 'Gyo-sa' is increasing. So the area of playground is decreasing. Second, The respondents require a playground size enough to contain 100m running track for testing the physical ability of students. But it is not possible to do so in current domestic condition, it is necessary to revise of the standard of physical test or enact a new one. Third, to solve the problems deviating from the playground size, the respondent suggests that set up a new gym or variable-size playgrounds rather than a large one Fourth, because playground has so much functions as rest, playing, walking and jogging etc besides physical education, it is necessary to consider the spaces for rest and play, when plan a tower-type school or small school.

• 한국수자원학회논문집
• /
• 제46권8호
• /
• pp.821-831
• /
• 2013

최근 수리 실험 및 계측 분야에 영상유속계가 많이 이용되고 있다. 그러나 영상유속계의 영상 분석에 대한 표준적인 방법과 측정 불확도가 정립되어 있지 않아 일반 사용자들이 사용하기 어려운 것이 사실이다. 특히 영상유속계를 이용한 유속 산정 시 상관영역 크기 결정에 대한 기준이 없기 때문에 사용자마다 유속 산정 결과가 차이가 나는 문제가 있다. 이에 본 연구에서는 영상유속계의 상관영역 크기 변화에 따른 오차분석을 통해 상관영역 크기 결정을 위한 자료를 제시하고 자한다. 오차분석을 위해 12개의 인공영상군을 제작하였으며, 다양한 입자수와 입자크기의 영상을 획득한 후 상관영역의 크기를 변화시키면서 산정한 유속을 인공영상의 유속 참값과 비교하여 오차분석을 수행하였다. 오차 분석결과 상관영역의 크기 변화에 따라 영상유속계로 산정한 유속값에 대한 오차가 달라짐을 확인하였고, 상관영역의 크기를 크게 결정할수록 오차가 줄어드는 것으로 나타났고, 동일한 상관영역의 크기로 유속을 산정할 경우 입자 크기가 증가할수록 또는 입자수가 증가할수록 오차가 작게 나타났다. 특히 영상유속계의 오차는 입자의 크기 보다는 입자수의 변화에 좀 더 영향을 많이 받는 것으로 나타났다. 또한 상관영역의 크기가 커짐에 따라 최대 오차와 최소 오차간의 간격이 줄어드는 것을 확인하였으며, 영상 전체에서 산정한 유속의 평균 오차가 5% 이하를 만족시키는 상관영역 크기를 기준으로 그 이하의 상관영역에 대해서는 최대 오차와 최소 오차간의 차이가 크게 나타나 영상유속계의 측정 불확실성이 큰 것으로 나타났다. 영상유속계의 신뢰수준별 입자밀도 변화에 따른 최소 상관영역의 크기를 분석한 결과 전반적으로 입자밀도가 커짐에 따라 상관영역의 크기는 작아지는 것으로 나타났지만 입자밀도가 작더라도 입자수가 큰 경우에는 신뢰수준을 만족시키는 최소 상관영역의 크기가 감소하는 것으로 나타났다.

• 대한안전경영과학회:학술대회논문집
• /
• 대한안전경영과학회 2004년도 춘계학술대회
• /
• pp.295-298
• /
• 2004

Situation to develop Kyonggi Province area to universal tourist attraction area keeping in step with national large size event holding such as sun of Korean visit with opening a port of the In-chon International airport, the world ceramics Expo, World Cup was made up. Growth possibility is big to culture tourism resources and representative tourist resort of the Korea that use view of nature photon circle properly such as ceramics that target area possesses. Area development plan through growth possibility should be arranged to international ceramics production complex and distribution complex. Therefore, plan analyzing future district theme establishment and strength in priority via past and present of target area.