• 제목/요약/키워드: korea-russia

검색결과 687건 처리시간 0.026초

고전압 펄스 발생기를 위한 강유전체의 전압 출력 특성 (The Characteristics of the Output Voltage Ferroelectrics for High Voltages Pulse Generators)

  • 장동관;최순호;황선묵;허창수
    • 전기학회논문지
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    • 제62권10호
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    • pp.1408-1412
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    • 2013
  • High power pulse generating technology is to accumulate the energy for relatively long and then to create a strong force by emitting the energy very fast. High power pulse generating technology has recently been using in various fields like environments, industry, research, military and so on. Numerous studies about high power pulse generators have already been performed and commercialized in various conditions. However, in aspect of their size and weight, it is hard to carry the generators which currently have been developed. For these reasons, din nations like America or Russia, the researches have been performed for Ferroelectric Generators(FEG), which have relatively simple structure and are economical. To realize the ferroelectric generator, in this study, we selected the PZTs which have different physical properties respectively, and then shocked them using explosives. The PZT samples with volumes of $0.31{\sim}0.94cm^3$ were depolarized by shocked and produced the waveform that have peak voltages of 4.28 ~ 15kV. The lowest relative permittivity sample generated much higher peak voltage. And sudden voltage drops which seem to be caused by dielectric breakdown were observed in some experiments using low young's modulus samples. Also, increase in thickness led to increase in peak voltage, but the ratio of the voltage rise did not reach the ration of the thickness increase.

Dexamethasone에 의하여 유발된 근육 위축 생쥐의 비복근 근섬유에서 apoptosis와 염증 반응에 미치는 오미자 추출물의 영향 (Effects of Schisandrae Fructus Supplementation on Apoptosis and Inflammatory Response in Gastrocnemius Muscle of Dexamethasone-Induced Muscle Atrophy Mice)

  • 최영현
    • 대한한의학방제학회지
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    • 제25권3호
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    • pp.363-374
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    • 2017
  • Dried fruits of Schizandra chinensis Baillon, Fructus Schisandrae, have been widely used for many years to prevent and treat various diseases in Asian countries including Korea and Russia. It has recently been reported that extracts of Fructus Schisandrae are effective for controlling muscle and skeletal diseases. In this study, we investigated the efficacy of ethanol extract of Fructus Schisandrae (EEFS) on apoptosis and inflammatory response in gastrocnemius muscle of dexamethasone-induced catabolic muscle atrophy mice as part of natural substance discovery and functional analysis for improving muscle function. According to the results of this study, EEFS supplementation attenuated body weight gains and suppressed calf thickness loss in dexamethasone-induced muscle atrophic mice. Gastrocnemius muscle immunohistochemistry showed that expression of caspase-3 and poly(ADP-ribose) polymerase, which are representative apoptotic markers, was markedly increased in dexamethasone control mice; however, their expression was effectively reduced in the EEFS-fed mice. EEFS supplementation also prevented dexamethasone-induced increases in immunoreactivity of muscle fibers for myostatin, an important negative regulator of skeletal muscle mass. In addition, EEFS significantly normalized the increased numbers of nitrotyrosine, 4-hydroxynonenal and inducible nitric oxide synthase-positive muscle fibers compared to that found in dexamethasone control mice. These results suggest that EEFS protects dexamethasone-induced muscular atrophy by decreasing apoptosis and inflammatory responses, and EEFS is more likely to be developed as a muscle strengthening agent.

지면경계조건이 UM을 이용한 동아시아 여름철 단기예보에 미치는 영향 (Impacts of Land Surface Boundary Conditions on the Short-range weather Forecast of UM During Summer Season Over East-Asia)

  • 강전호;서명석
    • 대기
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    • 제21권4호
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    • pp.415-427
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    • 2011
  • In this study, the impacts of land surface conditions, land cover (LC) map and leaf area index (LAI), on the short-range weather forecast over the East-Asian region were examined using Unified Model (UM) coupled with the MOSES 2.2 (Met-Office Surface Exchange Scheme). Four types of experiments were performed at 12-km horizontal resolution with 38 vertical layers for two months, July and August 2009 through consecutive reruns of 72-hour every 12 hours, 00 and 12 UTC. The control experiment (CTRL) uses the original IGBP (International Geosphere-Biosphere Programme) LC map and old MODIS (MODerate resolution Imaging Spectroradiometer) LAI, the new LAI experiment (NLAI) uses improved monthly MODIS LAI. The new LC experiment (NLCE) uses KLC_v2 (Kongju National Univ. land cover), and the new land surface experiment (NLSE) uses KLC_v2 and new LAI. The reduced albedo and increased roughness length over southern part of China caused by the increased broadleaf fraction resulted in increase of land surface temperature (LST), air temperature, and sensible heat flux (SHF). Whereas, the LST and SHF over south-eastern part of Russia is decreased by the decreased needleleaf fraction and increased albedo. The changed wind speed induced by the LC and LAI changes also contribute the LST distribution through the change of vertical mixing and advection. The improvement of LC and LAI data clearly reduced the systematic underestimation of air temperature over South Korea. Whereas, the impacts of LC and LAI conditions on the simulation skills of precipitation are not systematic. In general, the impacts of LC changes on the short range forecast are more significant than that of LAI changes.

다중 재난 상황에 적합한 COSPAS-SARSAT 탐색구조 비컨 위치추정 기법 (Beacon Geolocation Scheme of COSPAS-SARSAT System for Heavy Disaster Environment)

  • 김재현;이상욱;신천식;안우근
    • 한국위성정보통신학회논문지
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    • 제10권4호
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    • pp.146-150
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    • 2015
  • COSPAS-SARSAT 위원회에서는 2000년 이후부터 새롭게 발사되는 미국, EU, 러시아의 중궤도 항법위성에 탐색구조 탑재체를 탑재하여 중궤도 탐색구조(MEOSAR) 서비스를 제공키로 결정하였다. 비컨에서 송출되는 조난신호는 비컨 상공의 각 위성들에 각기 다른 도달시간과 도플러 주파수를 가지고 도달하며, 이를 바로 중궤도 수신국(MEOLUT)으로 전달한다. 중궤도 수신국에서는 적어도 3~4개의 위성을 동시에 추적하여 조난신호를 전달받고, 조난신호 간 TDOA(Time Difference of Arrival)와 FDOA(Frequency Difference of Arrival)를 이용하여 비컨의 위치를 추정한다. 그러나 비컨은 임의의 시간에 50초 간격으로 조난신호를 송출하므로, 대형 조난상황에서 비컨 신호가 겹치는 현상이 나타날 수 있고, 겹쳐진 비컨 신호들을 COSPAS-SARSAT에서 개발하고 있는 현재 방식으로 모든 비컨 위치를 추정하는 것은 어렵다. 따라서 여기에서는 이를 해결하기 위한 방안으로 CAF MAP 알고리즘을 소개하고, COSPAS-SARSAT 시스템의 성능 요구사항을 만족시킬 수 있도록 MCAF MAP 기법을 제안하고, 그 성능을 나타낸다.

고도 보정용 듀얼 벨 노즐 개발 동향과 기술 분석 (Technology Review and Development Trends of Dual-Bell Nozzle for Altitude Compensation)

  • 최준섭;허환일
    • 한국항공우주학회지
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    • 제43권5호
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    • pp.456-465
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    • 2015
  • 듀얼 벨 노즐은 일반적인 벨 형상 노즐의 문제점인 저고도에서의 과대팽창, 고고도에서의 과소팽창을 감소시키며, 이로 인해 손실되는 비추력을 최소화 할 수 있는 노즐이다. 미국의 Rocketdyne사에서는 확장 노즐의 형상에 따른 추력특성을 분석하였고, NASA에서는 고도에 따른 연소실험을 수행하였다. 유럽은 DLR을 중심으로 굴곡각, 노즐 길이, 팽창비 등에 따른 연구를 진행하고 있으며, 러시아의 MAI에서는 팽창부에 슬롯을 추가하여 추력손실을 줄일 수 있는 연구가 진행되고 있다. 아시아에서는 일본, 인도 등에서 연구가 진행되고 있고, 일본의 미쓰비시사에서 슬롯 노즐과 유사한 개념의 기술을 특허로 등록하였다. 본 논문에서는 고도 보정이 가능한 노즐로써 듀얼 벨 노즐의 개념 및 성능과 국외 연구 개발 현황을 정리하였다. 국내에서도 경제성 있는 우주개발을 위해 듀얼 벨 노즐에 대한 연구가 필요하다.

Contamination of Sediments and Histological Alterations in Barfin Plaice Pleuronectes pinnifasciatus from Amursky Bay(Peter the Great Bay, East Sea/Sea of Japan)

  • Vaschenko Marina A.;Syasina Iraida G.;Durkina Valentina B.;Zhadan Petr M.
    • Ocean and Polar Research
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    • 제25권1호
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    • pp.31-40
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    • 2003
  • In August-September 2001, 15 samples of bottom sediments were collected in the inner, middle and open parts of Amursky Bay near Vladivostok, Russia, and barfin plaice Pleuronectes pinnifasciatus was sampled from the inner and the middle locations of the bay. In the sediments from all three sites elevated concentrations of several heavy metals, i.e. Zn ($102-115{\mu}/g$ dry weight), Ni $(70-73{\mu}g/g)$ and Cu $(27-35{\mu}g/g)$ were discovered. The contents of oil hydrocarbons were very close to or slightly higher than the maximal normal environmental background level, $100{\mu}g/g$ dry weight. The sediments contained negligible amounts of hexachlorocyclohexane, while DDT concentrations were quite high (1.7-16.3ng/g dry weight). Generally, there were no substantial differences in the pollution levels of the locations studied and our results resembled those reported for Amursky Bay in the 1990s. Surprisingly, in 2001 'fiesh' DDT comprised 70-85% of the total DDT content in sediment from all the locations studied. In fish liver total DDTs concentrations were 212.8 and 122.54 ng/g wet weight for the inner and the middle locations, respectively, and 'fresh' DDT comprised 35 and 64% of DDTs, respectively. These results provide evidence of recent input of DDT from an unknown source into the ecosystem of Amursky Bay. Histopathological changes revealed in the plaice liver (vacuolization of hepatocytes, coagulative necrosis of hepatocytes, inflammatory reaction, and necrosis of epithelial cells of bile ducts) are probably connected with an intensive metabolism of DDT in the fish organism. No histological and histomorphometric differences were found in the state of the interrenal tissue. Similar condition of the liver and the interrenal tissue in barfin plaice sampled from the inner and the middle locations of Amursky Bay may be explained by the absence of great differences in the pollution levels of these sites.

시베리아 및 러시아-극동지역 방언 실태 조사 연구 -혼인예식(wedding)에 관한 어휘를 중심으로- (A Study on the Siberian and the Russian Far-eastern Dialects regarding the vocabularies on wedding)

  • 안병팔
    • 인문언어
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    • 제8집
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    • pp.291-313
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    • 2006
  • Previously, studies concerning the Russian dialects have been mainly focused on northern, central, and southern dialects limited to western Russia of Ural Mountains. On the contrary, the Siberian and Far-eastern dialects have been completely disregarded to the main stream of the Russian dialectology. As a result of a poll concerning this idea, the majority has answered that there is no dialect in Siberian and Far-east regions. Though the reasons for the outcome of the poll could vary, it could not be simply accepted that there is no dialect in such vast regions. Thus, a survey has took place to examine the existence of dialects in the regions of Siberia and Far-east. The first phase of the survey inquired the residents of the regions including Siberia and Far-east to respond to questions regarding 83 vocabularies on wedding in contrast to the regions covering western Ural and Moscow. The 23 informants were residents of the concerned regions who have come to visit Pushkin National Institute of Russian Language and, others, Korea. The questionnaires used in this survey were partly obtained from the questionnaires originated by the Language Institute of St. Petersburg National University. Although the limited range of regions and a small number of respondents who partook in this survey could raise some issues on the table, it is relevant to understand that this study would open up the path for the development of studies concerning regional dialects in the future.

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GPS/Galileo 시스템의 기하구조 및 영향 분석 (Analysis for Influence and Geometry of GPS/Galileo System)

  • 이재원
    • 한국항해항만학회지
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    • 제29권8호
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    • pp.763-770
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    • 2005
  • 위성을 이용한 측위 시스템인 광역위성항법시스템(GNSS : Global Navigation Satellite System)은 측량 및 항법 등에 정확한 위치, 속도 그리고 시간 정보를 제공함으로써 위치결정의 중요한 도구가 되어왔다. 미 국방성에 의해 개발되어 운용되고 있는 범세계적위치결정시스템인 GPS는 GNSS 시장에 독점적인 존재이므로, GNSS 사용자는 GPS에 의존할 수 밖에 없는 상황이다. 이런 독점 상황을 극복하기 위하여 러시아, 유럽 그리고 일본은 독자적인 위성항법시스템을 개발하기 시작하였다. 특히 유럽의 Galileo 시스템은 2008년 발사 목표로 진행되고 있다. 본 연구는 위성궤도를 생성하고 분석할 수 있도록 제작한 GIMS2005 프로그램을 이용하여 차세대 GNSS인 Galileo 시스템을 GPS와 비교 분석함에 있다. 본 실험은 GPS 단독 처리의 한계와 GPS/Galileo 결합 시스템의 이점을 인식할 수 있게 한다. 기하구조 분석은 가시위성수, 정밀도 저하율, 내부 신뢰도 그리고 외부 신뢰도를 GPS 단독 처리와 비교하여 분석된다.

민족적 색채(Ethnic color)기호의 분석을 통한 국가별 색채감성 (A Study of the International Color Sensibility through the Analysis of the Ethnic Color Preference)

  • 조은영;유태순
    • 복식
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    • 제62권6호
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    • pp.38-52
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    • 2012
  • The purpose of this study is to confirm the international unique color sensibility according to the ethnic color preferences. The existing studies about color sensibility were investigated to analyze the international color sensibility. The countries were chosen according to its, strong regional and racial color. Also, the documents and websites about environment color such as structure color, natural feature color, traditional folk costume color and customary color names were investigated, and then, the international color sensibility was analyzed by using the color image scale. As a result of the analysis about the differences of color sensibility, internationally distinguished color sensibility was discovered. There were differences not only for the preference trend of hue but also for the tone or contrast of color among the selected countries. Especially, Great Britain had a strong preference for G categories that they preferred the warm-grayish color image. Russia has a preference for R, G, and B categories with the preference for the warm-clear image. Netherlands had a preference for R, Y, and PB categories and it preferred the cool-hard-grayish, warm-soft-clear image. Italy had a preference for R and Y categories and it preferred the warm-clear image. Morocco had a preference for R and B categories and it preferred the warm and cool, clear image. Japan had a preference for R, G categories and it preferred the warm-grayish image. Korea had a preference for R and B categories and it preferred the warm-soft-clear, and cool-clear image. With these results, the researcher concludes that the integrated analysis of the environment color and the traditional racial color factors are very persuasive methods to comprehend the international color sensibility.

Analgesic and anti-inflammatory effect of the aqueous extract of root of Angelica Dahurica

  • Choi, In-Ho;Lim, Hyung-Ho;Song, Yun-Kyung;Lee, Jin-Woo;Kim, Young-Sick;Ko, Il-Gyu;Kim, Ki-Jeong;Shin, Mal-Soon;Kim, Khae-Hawn;Kim, Chang-Ju
    • Advances in Traditional Medicine
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    • 제7권5호
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    • pp.527-533
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    • 2008
  • Angelica dahurica (Umbelliferae) grows in China, Japan, Russia, and Korea. The root of Angelica dahurica has been used as a traditional folk medicine to treat headache and toothache. In this study, the effects of the aqueous extract of Angelica dahurica on acetic acid-induced abdominal pain, carrageenan-induced edema, and thermal hyperalgesia were investigated using mice and rats. The present results showed that the aqueous extract of Angelica dahurica inhibited acetic acidinduced abdominal pain in mice and reduced carrageen-induced edema in rats. The present study showed that the aqueous extract of Angelica dahurica possesses anti-inflammatory and analgesic effects.