• 제목/요약/키워드: NTO

검색결과 28건 처리시간 0.02초

해외 상용발사체의 RCS 개발 동향 (Current technology status for the Reaction Control System of Launch Vehicle)

  • 김인태;이재원;서혁
    • 한국추진공학회:학술대회논문집
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    • 한국추진공학회 2008년도 제31회 추계학술대회논문집
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    • pp.72-77
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    • 2008
  • 발사체 RCS는 발사체의 롤, 피치, 요방향의 자세제어뿐만 아니라 상단의 자세제어를 담당하는 핵심부품으로서 발사체의 임무요구조건에 따라 하이드라진을 이용한 단일추진제, UDMH/NTO를 이용한 이원추진제, 그리고 소형발사체의 경우 GN2를 이용한 냉가스시스템 등으로 분류된다. 본 연구에서는 해외 상용발사체를 중심으로 발사체에 대한 간략한 소개 및 RCS에 적용되는 최신 기술, 개발현황 등에 대해 기술하였다.

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Measurement of the Single and Size-Classified Raindrops

  • Ma, Chang-Jin;Mikio Kasahara;Hwang, Kyung-Chul;Park, Kum-Chan;Kim, Hui-Kang
    • Journal of Korean Society for Atmospheric Environment
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    • 제15권E호
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    • pp.73-79
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    • 1999
  • To Characterize the single raindrops as a function of their size we designed the sampling and handling apparatuses. Samplings of single and size- classified raindrops were performed at a height of 20m above the ground level of a Kyoto University building located in Uji, Japan in rain events from middle of July to the end of August, 1999. And PIXE method was applied to the analysis of single raindrops sampled as a function of their size. Diameter change of frozen raindrops by liquid nitrogen did nto affect the size segregation ability of our sampling apparatus. The number of raindrops increases with decreasing drop size. And it is found that the size distribution of raindrops verified depends on the rain events. Application of PIXE analysis to the measurement of single raindrops was very successful. Every element showed a continuous increase in concentration with decreasing raindrop diameter. It seems reasonable to say that our work should be helpful to obtain more detailed information on single raindrops and especially to study on the rainout and washout mechanisms.

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투과곡선을 이용한 La 농도에 따른 PLT 박막의 광학적 특성에 관한 연구 (A study on the optical properties of PLT thin films with varying the La concentration by using the transmission spectrum)

  • 강성준;윤석민;윤영섭
    • 전자공학회논문지D
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    • 제34D권5호
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    • pp.22-31
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    • 1997
  • We have measured the optical properties, thickness, and energy band gap of the P $b_{1-x}$/100/L $a_{x}$100/ $Ti_{1-}$0.25x/100/ $O_{3}$ (PLT(x)) thin film prepared by the sol-gel method with varying the La concentration, x, fyom 15 nto 33 mol%. We have obtained the values from the tranmission spectrum and employed the envelope method in anayzing the spectrum. We have also performed the simulation of the transmission spectrum on the PC (personal computer) to verify the accuracy of the values 15 to 33mol%, the refractive index (at .lambda.=632.8nm) increases from 2.39 to 2.44. The extinction coefficient does not depend on the la concentration but mainly on te wavelength, and has the values between 0.2 and 0.5 at the wavelength shorter than 330nm and between 0.001 and 0.008 at the wavelength longer than 700nm. The energy band gap of the PLT (x) thin film has been obtained on the assumption of the direct band-to-band transition. It decreases from 3.28 to 3.17eV as the La concentration increases from 15 to 33 mol%. The thickness of the PLT(x) thin film has been also obtained in high accuracy by the envelope method..

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1945년 이후 우리나라 쇠고기 찜류의 문헌적 고찰 (Historical Study on Steamed Beef Recipe Since 1945 in Korea)

  • 김미옥;김태홍
    • 동아시아식생활학회지
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    • 제10권1호
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    • pp.1-20
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    • 2000
  • The purpose of this study was to survey the various kinds of cooked beef products focusing on "chim" (a steamed beef recipes) through historical literatures written from 1945 to 1997 in Korea. " Chim" was recorded 96 times in the references and could be classified into 3 groups based on major ingredients suchas the cud pouch, liver , spine , tongue, fleshes, beef, rib and tail, an could be classified into 14 groups based on minor ingredients such as vegetables fried beef in egg batter. tomatoes, callion and rice cake. Among the seventeen cooked recipe of " chim", "kalbi chim(rib) " was recorded most frequently and "satae chim(shank)" was the next. Though "yang chim(the cud pouch), salkogi chim(fleshes), sokalbi chim(rib) and sokori chim (tail) " has been sued until present day, salkogi chim subdivided into satae chim, udun chim, nubianisam chim, sosim chim in the middle twenty centuries. Ribs was most popular ingredient among the major ingredients such as the cud pouch, liver, spine, tongue, tail, fleshes. Decorating ingredients such as sukgi mushroom, minarichodae, pyoko mushroom, gingkonut also come into use subingredients or decorating ingredient in the 1990.nto use subingredients or decorating ingredient in the 1990.

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포집된 Bifidobacteria의 생존력 증대를 위한 세포포집재료의 선별기술 개발 (Development of the Selection Technique of Entrapment Materials for the Viability Improvement of Entrapped Bifidobacteria)

  • 이기용;우창재;배기성;허태련
    • KSBB Journal
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    • 제15권1호
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    • pp.1-8
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    • 2000
  • The diffusion effect of simulated gastric juices into the various alginate vessel containing each biopolymer such as 0.3% soluble starch, whey, corn starch, agar, locust bean gum, guar gum, gum arabic, pectin, gelatin and 0.15% xanthan gum was tested by measuring the change of pH in the vessel. The degree of viability of bifidobacteria entrapped in each bead containing biopolymers was corresponded with the degree of diffusion inhibition of hydrogen into the each vessel. Therefore, The determination of diffusion inhibition of simulated gastric juices into the various vessel by measuring the change of pH in the vessel may be effectively used as the simple method to select the optimal entrapment lattice for the improvement of bifidobacteria viability. Bifidobacteria entrapped in alginate bead containing 0.15% xanthan gum whose lattice showed the lowest hydrogen diffusion were more significantly tolerant against bile salts and hydrogen peroxide than untrapped bifidobacteria. It was also observed that the viability of bifidobacteria entrapped in bead was nto nearly changed in milk adjusted pH 4.5 with organic adids at $4^{\circ}C$ for 10 days. Therefore, use of alginate containing 0.15% xanthan gum as a cell matrix for entrapping bifidobacteria was expected to improve the viability of bididobacteria in fermented milk products and develop the high value-added products.

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휴리스틱 기법을 적용한 촬영계획 최적화에 대한 연구 (Development of Image Collection Planning Optimization Using Heuristic Method)

  • 배희진;전정남;채태병
    • 대한원격탐사학회지
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    • 제28권4호
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    • pp.459-466
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    • 2012
  • 위성영상 운영은 주문접수, 촬영계획, 영상처리, 영상 배포의 과정으로 구분하며 촬영계획은 주문 접수 과정에서 전달된 신규 주문과 이미 진행 중인 주문을 바탕으로 한정된 위성자원을 최대한 활용하여 사용자의 촬영요청을 가능한 적절한 시기에 반영할 수 있도록 위성의 촬영계획을 수립하는 과정으로 위성 자원의 효율적인 활용이라는 취지와 가장 밀접한 관계를 갖는 과정에 해당한다. 촬영계획은 동시에 많은 변수를 고려해야 하기 때문에 연산량도 많은 편이며, 스케줄링을 수행할 때마다 동일한 과정을 반복적으로 수행해야 한다. 본 논문에서는 촬영계획의 효율성을 높이기 위해 촬영계획의 최적화 연구를 수행하였다. 먼저 촬영계획 수행과정과 제약조건을 정리하여 가능한 많이 촬영할 수 있도록 촬영계획 모형을 수립하고 그 모형을 해결하기 위해 휴리스틱 알고리즘을 제안하였다.

우리 나라 농촌지역(農村地域)에 부합하는 1차(次) 보건의료전달체계(保健醫療傳達體系) 정착구현(定着具現)에 관한 연구(硏究) -마을 보건임원(保健任員) 개발(開發)- (A Study on Implementation of Primary Health Care Delivery System meet to Rural Area in Korea -Village Health Voluntary Worker Development-)

  • 구연철;위자형;황선정;최삼섭
    • Journal of Preventive Medicine and Public Health
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    • 제12권1호
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    • pp.13-23
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    • 1979
  • A study was carried out from October 1977 to September 1978 in order to develope health care delively system which will meet to rural area in Korea. For the study objective a model of health care delivery system of Myun (township) area was developed which is adopted the net-work of village health voluntary worker who will play the role of bridge for communication related with health and illness between families or village people and health subcenter, and :he model health care delivery system net-work was set in the area of Soodong Myun, Yangju Gun. which is the rural health demonstration area of Ewha Womans University since 1972. The activities and attitude of 22 village health voluntary workers were observed and analized. during the study period. The results are as follows; 1. For the field activities of village health voluntary workers. a guide line which is described with specific behavioral objectives was developed and used for not only training of the workers but also evaluation of their field activities. 2. During the study period, the number of 971 village people were served primary health care service by village health voluntary worker and the service was classified largely into symptomatic medications (92%) and preventive measures (8%). 3. Comparative percentage of the number of 894 symptomatic cases cared by village health voluntary workers to 5,695 cases of patient treated by Soodong Health Subcenter during the same period was 15.7%. 4. Annual utility rate of village health voluntary worker by Myun total people was 16.1% but utility rate by Rie was varied from 38.2% to 2.8% which shown there were considerable differences in each Rie. In order to settle the village health care service, the obstructive factors of utility should be detected and their counter measure must be taken. 5. As the health need of village people increases, it is expected that the supplement of drug excluding present sit basic drugs is inevitable, but considering the ability of village health voluntary worker, the selection of additional drugs and education, plan should be carefully studied. 6. It is desirable that a financial resource for supplementary purchase of first aid kit, drugs and materials whould be alloted from village public fund like Saemaeul Women's Club fund, which has already practiced in a few villages in the study area. 7. As pointed out by village health voluntary workers, in order to improve the village health, village leaders should be in the center of it and the cooperation of whole village people is a core of healthful village development, and it is reasonable that the health subcenter backs up these voluntary health activities by village people in techniques. 8. It seems effective that a supplementary education for village health voluntary worker be accomplished by a planned education through regular meetings like worker's monthly meeting and irregular post guide when Myun Health Workers can handle the problems found during the round trip of villages. 9. It is desirable that village health voluntary workers, who are recommended by a civil voluntary organization like Saemael Woman's Club, are charged by natural villagc unit, are given a function of village health care service and used through basic education at health subcenter. 10. It is advisable that the village health voluntary worker's service is compensated not by a form of money, but by other way such as an exemption of medical fee of worker herself or her families in health subcenter can be one method. 11. Daily health activities of each village health voluntary worker should be reported to health subcenter by biweekly or monthly in order to get not only for basic data of the program but also for evaluation the program. It is recomandable that the report form should be simple and clear enough for village health voluntary worker to fill it effectively. 12. Village health care service should be developed into a Saemaeul Movement in which village people actively participate. For this, the appointed function of village health voluntary worker should be absorbed into those of living Environment Betterment Section or Family Planning Section of Saemaeul Women's Club or it is desirable that establish a new section, Village Health Promoting Section and make it involve the appointed functions of those sections mentioned above.

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중앙아시아 농업분야 진출을 위한 현황분석 - 우즈베키스탄, 카자흐스탄, 키르기즈스탄 중심으로 - (A Study on Status Analysis for Advancement iNto Agricultural Sector in Central Asia)

  • 박동진;조성주;박정운;사수진;홍정식;이동진
    • 한국국제농업개발학회지
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    • 제30권4호
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    • pp.328-338
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    • 2018
  • 본 연구는 동서양을 잇는 유라시아 지역에 위치한 중앙아시아 3개국의 농업현황과 농업기술협력 현황, SWOT 분석을 통해 농업분야 진출 방안 등에 대한 논하고자 하며, 결과를 요약하면 다음과 같다. 1. 우즈베키스탄, 카자흐스탄, 키르기즈스탄은 농촌인구 비중이 상당히 높고 농업에 종사하는 인구도 많은 국가들로써, 천연자원이 풍부하고 경제성장율이 높아 앞으로 발전 가능성이 상당히 높고 고려인이 많이 거주하고 우리나라고 진출하는데 용이한 국가들 중 하나이다. 2. 또한, 이들 국가들은 농업발전을 위해 정책자금, 연구단지 조성, 외국인 투자 등 강력한 정책 추진으로 농업을 통한 경제발전을 이루고자 한다. 3. 우리나라는 이들 3개국과 1972년부터 농업기술 훈련을 통해 총 107명을 훈련하였으며, 우즈베키스탄 KOPIA 센터를 통해 농업생산성 향상에 대한 공동연구를 수행하고 있고 농산업 진출을 위해 카자흐스탄, 키르기즈스탄에 국내 농기자재 해외테스트 시험 및 실증으로 우리 기업의 진출 가능성에 대한 연구를 수행하고 있다. 4. 온도 편차가 심한 기후적 특성으로 과채류 및 하우스시설에 대한 수요가 증가되고 있으며 자국내 농업생산물의 자급율을 높이기 위해 외국인 투자 유치를 통한 생산성 향상에 힘 쓰고 있는 것과 더불어 농업기계화를 통한 시설 현대화에도 많은 노력을 기울이고 있다. 지리적으로 가까운 중국은 일대 일로 정책과 함께 상대적으로 높은 가격경쟁력을 바탕으로 중앙아시아 시장을 선점해 나가고 있는 상황이다. 5. 국내 농산물과 농기자재산업이 포화상태로 새로운 수출시장이 절실히 필요한 상황으로 높은 경제 성장률 및 인구증가율을 바탕으로 성장하는 중앙아시아 시장에 대해 사전에 시장을 분석함으로써 진출의 위험을 최소화하는 것이 필요하다. SWOT 분석을 통해 이들 국가의 내외부 환경에 대한 사전 인식을 바탕으로 우리나라에 비해 저렴한 노동임금과 풍부한 노동력을 보유하고 있고 지리적으로 유라시아 시장의 중심부에 위치하여 향후 급변하는 남북의 철도시대를 대비한 중앙 아시아의 물류 허브의 역할을 수행할 수 있는 이들 지역에 지금이나마 진출을 활성화해야 할 것이다. 또한, K-Pop, 드라마 등 한류문화의 유입으로 인한 한국제품에 대한 선호도가 높으며 다양한 발전 정책으로 인해 시장이 열려 있어 철저한 준비를 통한다면 무한한 기회가 될 것이며 상대적으로 높은 우리 기자재의 가격 경쟁력만 확보 된다면 수출 가능성이 있을 것으로 예측된다.