• 제목/요약/키워드: Kan

검색결과 485건 처리시간 0.024초

로켓엔진 고공환경 모사용 디퓨져의 냉각 채널 열 해석 (Thermal Analysis of Exhaust Diffuser Cooling Channels for High Altitude Test of Rocket Engine)

  • 조기주;김용욱;강선일;오승협
    • 항공우주기술
    • /
    • 제9권2호
    • /
    • pp.193-197
    • /
    • 2010
  • 로켓엔진 고공 환경 모사용 디퓨져에는 연소가스의 고열로부터 디퓨져를 보호하기 위해 물을 이용한 냉각시스템이 사용되며 냉각수의 유량 및 압력은 냉각 채널 내부에서 냉각수의 비등이 발생하지 않도록 결정된다. 따라서 냉각수 유량의 변화에 따른 냉각 채널 벽면의 최고온도 예측은 냉각시스템의 운용 압력을 결정하는데 주요한 변수가 된다. 본 연구에서는 열평형 이론에 근거하여 유량 변화에 따른 채널 벽면의 최고온도를 예측하는 방법을 기술하였다.

한국 전통 간장과 된장의 숙성 중 미생물상의 변화(제1보) -Bacillus sp.를 중심으로-

  • 김종규
    • 한국환경보건학회:학술대회논문집
    • /
    • 한국환경보건학회 2005년도 가을학술대회
    • /
    • pp.101-103
    • /
    • 2005
  • This study was performed to investigate the changes of Bacillus sp. of traditional Korean soy sauce (kan-jang) and soybean paste (doen-jang) during the ripening and storage for 12 months. All of the preparation methods for soy sauce and soybean paste followed the recommendations of the Korea Food Research Institute. The soy sauce and soybean paste were analyzed at 0, 6, and 12 months. The numbers of Bacillus sp. of meju (soybean cakes) or soy sauce and soybean paste at the initial stage were significantly higher than those of soybeans (p<0.05). The number of Bacillus sp. increased in soy sauce and soybean paste after 12 months of ripening and storage. This study indicates that this comes from the preparation and fermentation of meju. It is suspected that the organoleptic characteristics of soy sauce and soybean paste might be inferior over 1 year of storage time. Therefore, more research fur overall microbiological quality changes of soy sauce and soybean paste during the storage period should be conducted to interpretate this characteristics more accurately.

  • PDF

버블기를 넘어선 SDN 기술동향 및 발전전망 (Trends and Forecast of SDN Technology Crossing Peak of Hype Cycle)

  • 최태상;강세훈;김영화;양선희
    • 전자통신동향분석
    • /
    • 제29권4호
    • /
    • pp.123-136
    • /
    • 2014
  • SDN 기술은 2011년부터 2013년까지는 Hype 사이클상 발생기 및 버블기를 지나는 동안 주로 기술의 필요성에 대한 논의가 많이 이루어져 왔고 기술개발도 적합성 검증 차원의 연구개발 및 Proof of Concept 정도의 서비스 시도가 단편적으로 제공되어 왔었다. 2014년을 접어들면서 각성기의 초기 단계로 관심도가 감소하고 얼리어탑터를 중심으로 1단계 SDN 기술, 상품 및 서비스가 유통되기 시작하고 있다. 본고에서는 이러한 진화과정을 거치고 있는 SDN 기술의 최근 기술동향에 대해 주요 3 계층인 인프라, 컨트롤러, 응용계층별로 학계/연구소, 산업체, 서비스 및 통신사업자, 표준화 단체에서 추진 중인 기술개발, 표준화 현황 및 적용사례에 대해서 소개하고 향후 SDN이 나아갈 발전방향에 대한 전망을 소개한다.

  • PDF

A Study on Hull Deflection and Shaft Alignment Interaction in VLCC

  • Lee Yong-Jin;Kim Ue-Kan
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제29권7호
    • /
    • pp.785-794
    • /
    • 2005
  • Modern ship hulls of large oil carriers and container carrers have become more flexible with scantling optimization and increase in ship length. On the other hand. as the demand for power has increased with the ship size. shaft diameters have become larger and stiffer. Consequently. the alignment of the propulsion system has become more sensitive to hull girder deflections. resulting in difficulties in analyzing the alignment and conducting the alignment procedure. Accordingly. the frequency of shaft alignment related bearing damages has increased significantly in recent years. The alignment related damages are mostly attributed to inadequate analyses. changes in the design of the vessel. shipyards' practices in conducting the alignment. and a lack of well defined analytical criteria. The hull deflections should be considered at the design stage to minimize the bearing damage caused by hull deflection. Hull deflections can be estimated by analytical approach and reverse calculation using the measured data. The hull girder deflection analysis using the reverse calculation will be introduced in this paper.

강판의 진동모드를 고려한 방사음 예측에 관한 연구 (Effect of the Vibration Modes on the Radiation Sound for Plate)

  • 김창남;변용수;김정만;김의간
    • Journal of Advanced Marine Engineering and Technology
    • /
    • 제30권1호
    • /
    • pp.73-80
    • /
    • 2006
  • In order to compute the radiated sound from a vibrating structure, the Rayleigh's integral equation has to be derived from the Helmholtz equation using Green's function. Generally, the surface velocity in the Rayleigh's integral equation uses the root mean square(rms) velocity. The calculation value is too large, because it's not considered cancelation. On the other hand. using the complex velocity, the sound pressure is calculated too small, because it considers that sound is perfectly canceled out. Therefore, this thesis proposes a correction factor(CF) which considers vibration modes and the method by which to calculate the radiating sound pressure. The theoretical results are compared with the experimental values, and the proposed method can be verified with confluence.

Utility-based Resource Allocation with Bipartite Matching in OFDMA-based Wireless Systems

  • Zheng, Kan;Li, Wei;Liu, Fei;Xiang, Wei
    • KSII Transactions on Internet and Information Systems (TIIS)
    • /
    • 제6권8호
    • /
    • pp.1913-1925
    • /
    • 2012
  • In order to efficiently utilize limited radio resources, resource allocation schemes in OFDMA-based wireless networks have gained intensive attention recently. Instead of improving the throughput performance, the utility is adopted as the metric for resource allocation, which provides reasonable methods to build up the relationship between user experience and various quality-of-service (QoS) metrics. After formulating the optimization problem by using a weighted bipartite graph, a modified bipartite matching method is proposed to find a suboptimal solution for the resource allocation problem in OFDMA-based wireless systems with feasible computational complexity. Finally, simulation results are presented to validate the effectiveness of the proposed method.

조선시대 연화문(蓮花紋)을 모티브로 한 현대패션디자인 연구 (Research on modern fashion design using the Chosun Dynasty's Lotus pattern as the motif)

  • 조예석;간호섭
    • 패션비즈니스
    • /
    • 제14권1호
    • /
    • pp.116-131
    • /
    • 2010
  • As our world is becoming more and more globalized, nations tend to turn their interests towards their unique legacy and traditional culture. This research is intended to re-illuminate the Korean beauty through the Lotus Pattern, a traditional factor, from the Chosun Dynasty, and at the same time, analyze how its peculiar representation and figural elements can be reflected in modern fashion designs. The results will be an essential factor in creating exclusive and original designs. Research method was theoretical research from documents and to refer to positive data on preserved relics, and research contents consists of analysis on the use of lotus patterns in artworks that were exhibited during 2000 to 2008 by Korean and foreign artists. Results showed that lotus patterns that were used during the Chosun Dynasty are categorized by shape, composition form, and structural form. Applying these results, a total of 8 works were designed and created.

EFFECTS OF DIETARY AFLATOXIN B1 ON PERFORMANCE, ON HEMATOLOGIC, PATHOLOGIC AND IMMUNOLOGIC CHANGES IN BROILER CHICKENS

  • Yun, Yeo-Pyo;Kim, Kan-Hol;Han, Sang-Bae;Chung, Chung-Soo;Jeong, Goo-Bo
    • Toxicological Research
    • /
    • 제8권1호
    • /
    • pp.83-94
    • /
    • 1992
  • The influences of dietary aflatoxin B1 on performance, on hematologic, pathologic and immunologic changes in broiler chickens were studied. One hundred and fifty hatched broiler chickens were fed with diet containing aflatoxin B1 (1.0 ppm and 2.5 ppm) fot three weeks. Blood samples, serum, and immune organs were obtained to investigate hematological, clinico-chemical, and histopathologial changes. Body weight gain and feed intake were significantly decreased. The liver and kidney were increased, whereas the bursa of Fabricius, spleen and thymus were decreased.

  • PDF

우리나라 저장식품중의 NaCl 함량 (NaCl Content in Korean Storage Foods)

  • 박영란;박봉옥
    • Journal of Nutrition and Health
    • /
    • 제7권1호
    • /
    • pp.25-29
    • /
    • 1974
  • In order to help food habits of Korean, major foods of side dishes in Korean foods were analyzed by Mohr's Silver Nitrate Method. The kinds of foods were Kanchang (Sa)Sauce) Kochuchaag(Redpepperbean paste), Doeuchang(Soy bean Paste) and Kimchies, and selected into 3 areas in Korea; Seoul (city area), Kyung Puk Province (Fishery area) and Chun-Puk Province (Farming area). The results are as follows; Average NaCl content of Kan-chang is 26.04g/dl ranged from 24.27 to 28.22g/dl and among them Farming area is the highest content. In Ko-chu-chang, average content is 11.36g% ranged from 10.77 to 11.60g%. Doen-chang has an average 15.89% ranged from 13.28 to 18.54g% and in Kimckies they were resulted 3.36g%.

  • PDF

우리나라 전력산업 기술현황과 발전방향 모색 (The Study on the Present State of Power Industry Technology and Future Development Direction)

  • 이근준;박희철;허간도
    • 한국조명전기설비학회:학술대회논문집
    • /
    • 한국조명전기설비학회 2005년도 춘계학술대회논문집
    • /
    • pp.378-384
    • /
    • 2005
  • This paper presents the prospects of today's situation of Korea Electric Power Industry and future's development direction at the sudden chin international environment Several paradigm,-Deregulated electric market Energy shortage, Green house effect due to $CO_2$, TBT(Technical Barrier to Trade), Digital society-will facilitate the glove to develope new technology based Power Industry. With respect to this change, Korea Power Industry needs to find new technology solutions for the smarter operation, higher efficiency and lower carbon consuming power system based on mid-long term plan.

  • PDF