• 제목/요약/키워드: LED Stand

검색결과 50건 처리시간 0.023초

The influence of the water ingression and melt eruption model on the MELCOR code prediction of molten corium-concrete interaction in the APR-1400 reactor cavity

  • Amidu, Muritala A.;Addad, Yacine
    • Nuclear Engineering and Technology
    • /
    • 제54권4호
    • /
    • pp.1508-1515
    • /
    • 2022
  • In the present study, the cavity module of the MELCOR code is used for the simulation of molten corium concrete interaction (MCCI) during the late phase of postulated large break loss of coolant (LB-LOCA) accident in the APR1400 reactor design. Using the molten corium composition data from previous MELCOR Simulation of APR1400 under LB-LOCA accident, the ex-vessel phases of the accident sequences with long-term MCCI are recalculated with stand-alone cavity package of the MELCOR code to investigate the impact of water ingression and melt eruption models which were hitherto absent in MELCOR code. Significant changes in the MCCI behaviors in terms of the heat transfer rates, amount of gases released, and maximum cavity ablation depths are observed and reported in this study. Most especially, the incorporation of these models in the new release of MELCOR code has led to the reduction of the maximum ablation depth in radial and axial directions by ~38% and ~32%, respectively. These impacts are substantial enough to change the conclusions earlier reached by researchers who had used the older versions of the MELCOR code for their studies. and it could also impact the estimated cost of the severe accident mitigation system in the APR1400 reactor.

백색광 LED를 사용한 독서등의 최적 색온도에 따른 사람의 시력 변화 연구 (Research a Person's Eyesight Changes on According to the Optimum Color Temperature for the Stand Lamp Using White Light LED Sources)

  • 김주현;장원범;이석환;정광교;김동현;김정미;류재준;문성득;이승현;고영수;허산;장미나;정창호;장지호
    • 한국전기전자재료학회논문지
    • /
    • 제26권1호
    • /
    • pp.80-82
    • /
    • 2013
  • White light emitting diode (LED) determined the most appropriate color temperature in reading lighting evaluated fatigue degree of eye according to color temperature. The eye fatigue degrees are determined by brightness and color temperature. Therefore, we measured the results of eyes test according to the change of color temperature and brightness. Experiments except for astigmatic corrected visual acuity of 0.8 more and age 20 to 25 years old, male and female college students was conducted in 100 patients. And constant illumination conditions, visual acuity was measured by varying the color temperature. The optometry at 10 minutes in the darkroom adapted eye. And then the temperature of $25{\pm}3$ degrees, the humidity was carried out at $50{\pm}5%$. As a result of typical color temperature of white light (5,600 K) has identification of the readability.

기업과 대학간의 산학협력마케팅 전략모델 구축에 관한 연구 (Establishing a marketing strategy model for academic-industrial cooperation between companies and universities)

  • 윤정근
    • 유통과학연구
    • /
    • 제12권4호
    • /
    • pp.65-72
    • /
    • 2014
  • Purpose - Because of the emphasis on the necessity of academic-industrial cooperation between companies and universities, there are various ongoing academic-industrial cooperation programs led by the government. As government actively supports such cooperation as policy,and universities vitalize new technology development, academic-industrial cooperation between companies and universities is being recognized as an important growth engine for companies the competitiveness of academic-industrial cooperation is also attracting more interest. The government has vitalized human resource fostering, practical R&D, and technology transfer to companies since 2012 by executing a "leading university fostering project for academic-industrial cooperation." Based on an organic interlink among universities, industry, and research institutes, the government also created and is promoting several models of such cooperation between companies and universities to support shared growth of industry and local universities. The purpose of academic-industrial cooperation is growth and benefit fromtechnology development, technical cooperation, and technology transfer between companies and universities. Research design, data, and methodology - As more academic-industrial cooperation efforts are ledby companies due to the limitation in technology-focused commercialization cooperation, the academic-industrial cooperation system became fragmented and it is losing the potential for future advancement. Specifically, as differences between universities grow, academic-industrial cooperation between companies and universities based on new technology from universities is finding difficulty advancing,while systematic support from companies to enhance the performance of businesses created by academic-industrial cooperation is also insufficient. Accordingly, this study established a growth model for the advancement of academic-industrial cooperation between companies and universities and suggested a plan to strengthen the competitiveness and promote the future advancementof academic-industrial cooperation between companies and universities by analyzing the current situation of such cooperation and diagnosing its issues. Results - This study explored the concept and current status of academic-industrial cooperation relationships and analyzed related issues. For such cooperative organizations to be competitive, the employment environment of professional human resources for academic-industrial cooperation should be improved and measures to secure professional resources should be taken as early as possible. Though the academic-industrial cooperation now is being led by government, there is a limitation based on business models, which require creation of profit; however, an academic-industrial cooperation model still cannot stand alone without the support of government. This study also pointed out that a having only a plan to build competitiveness of companies and universities for academic-industrial cooperation is not sufficient. Conclusions - In order to increase the competitiveness of academic-industrial cooperation, a detailed growth-sharing model for academic-industrial cooperation should be developed, and there should be more joint development processes for the advancement of such cooperation in which the need for technology development can be verified in advance. In addition, beyond focusing on technology-focused academic-industrial cooperation, a network between companies and universities searching for ideas for academic-industrial cooperation in the fields of human and social aspects should be created. A new academic-industrial model linking current cooperation between companies and universities to the local area should be built based on such academic-industrial cooperation in human and social fields.

수제 접촉각 측정기와 영상 분석 프로그램을 이용한 표면에너지의 측정 (Determination of Surface Energy by Means of Home-Made Goniometer and Image Analyzing Software for Contact Angle Measurement)

  • 조서린;조한국
    • 대한화학회지
    • /
    • 제57권4호
    • /
    • pp.432-438
    • /
    • 2013
  • 기초 화학 실험에서 쉽게 만들고 운용할 수 있는 접촉각 측정기를 구성했다. LED 손전등과 시료 거치대, 디지털 카메라를 광학보드에 고정했고, 시료부는 양쪽에 구멍이 뚫린 암실 상자로 덮었다. 공개된 영상분석 프로그램(ImageJ)과 플러그인(Drop_analysis)을 이용해서 고체 표면 위에 형성된 액체 방울의 사진으로부터 접촉각을 측정했다. 구성된 측정기와 해석 프로그램을 이용해 여러 액체와 다양한 표면에서의 접촉각을 측정해 측정기의 성능을 확인했다. 측정된 $H_2O$$CH_2I_2$ 접촉각으로부터 결정된 고체의 표면에너지들은 알려진 값들과 대체로 일치하며 표면의 특성과 개질, 비극성 및 극성 기여도 등을 충실히 보여준다. 이 논문에 소개된 수제 접촉각 측정기와 측정법을 활용해 기초 화학을 배우는 학생들이 젖음성, 친수성, 발수성 등 표면 특성들과 분자 간 상호작용을 이해하고 관련된 힘의 평형, 광학, 수식의 전개 등을 경험할 수 있다.

잣나무의 낙엽송림(落葉松林)에 있어서 수형(樹型)과 재적간(材積間)의 관계(關係) 비교(比較) (A Comparative Study on the Relationship between Tree Form and Volume in Stands of Pinus koraiensis and Larix leptolepis)

  • 김지홍;이종구
    • 한국산림과학회지
    • /
    • 제74권1호
    • /
    • pp.82-87
    • /
    • 1986
  • 대다수의 잣나무가 잣을 수확(收穫)하는 과정에서 수간(樹幹) 정단부(頂端部)의 인위적인 손상으로 말미암아 전형적인 잣나무 수형(樹型)을 잃게되는 점에 착안하여, 정상적으로 생육한 낙엽송과 비교하여 임본(林木) 제형질(諸形質)들의 관계를 조사 연구하였다. 동령급(同齡 級)의 두 수종(樹種)을 비교한 결과, 잣나무는 원단부(原端部)의 절단(切斷)으로 인하여 정상적인 수고생장(樹高生長)을 못하고 있음을 알 수 있으며, 또한 심하게 분간(分幹)되거나 굴곡된 수간(樹幹)은 이용재적(利用材積) 값을 낮추는 결과를 초래하여 본재생산(木材生産)의 측면에서는 바람직한 수형(樹型)을 갖지 못하고 있었다. 그러나 잣을 수확(收穫)할 수 있고 용재(用材)를 생산할 수 있는 잣나무의 특성을 감안하여, 조림투자(造林投資)에 대한 회수율(回收率)을 최대화하기 위한 잣나무 식재림(植栽材)에 대한 경영적(經營的) 대안(代案)을 제시하였다.

  • PDF

그린캠퍼스를 위한 국내.외 대학시설관리(FM) 비교분석 - 에너지관리 중심 - (A Comparative Analysis of Domestic and Foreign Universities' Facility Management for Green Campus - Focusing on the Energy Management -)

  • 신은영;김준하
    • 교육시설 논문지
    • /
    • 제19권1호
    • /
    • pp.45-53
    • /
    • 2012
  • Recently, as the environment issue has been stand out, people's interests in energy consumption of the building have been increased as well. Especially, university has been classified as the one of the main causes of excessive energy consumption. Therefore, domestic and foreign universities are trying to build a green campus in an attempt for sustainable development. Since early 2000s, foreign universities have been aware that one of the main causes of global warming is an excessive consumption of energy in universities. Accordingly, they adopted various energy management programs for the conservation. Ultimately, enforcing energy conservation and using alternative energy resulted in lower expense and it was a great help for the universities. On the other hand, excessive consumption of energy in domestic universities has been considered as serious, which led them to become the second main energy consumers in 2010. However, it seems people do not truly recognize the impotance of energy management, therefore, relatively little attention has been paid to this matter. Based on Leadership in Energy & Environmental Design(LEED) rating systems for on-campus building operation and maintenance, this research suggests the evaluation standard to effectively analyze the energy management activity with the best practices conducted in foreign universities and to solve the problem of campus facilities management in domestic universities. The result shows that domestic universities do not have a designated task force for effective energy management and the lack of energy professionals hinders for the long term development. Therefore, domestic universities should recognize the seriousness of the excessive energy consumption and develop low carbon green campus through proactive management practices since this is very essential for domestic universities to get more competitive in this global era.

20세기 초 한국과 유럽의 부엌 계획특성에 관한 비교연구 - 박길용의 개량부엌과 독일 프랑크푸르트 부엌을 중심으로 - (The Comparative Study on Characteristics of the Kitchen Design of 20 century's Korea and Europe - Centered on Park Gil-Yong's improved kitchen and German Frankfurt kitchen -)

  • 정찬미;김현정
    • 한국실내디자인학회논문집
    • /
    • 제18권2호
    • /
    • pp.50-60
    • /
    • 2009
  • The change of idea about overall politics, society, technology, and culture in 20th century led to the change of kitchen which is the central space of household affairs as well. Frankfurt kitchen of Margarete Schuette Lihotzky which was introduced for the first time at Germany International Trade Exhibition in 1927 functionally designed small space of $6.5m^2$ with considering move-line and convenience. This is the beginning of kitchen type which has built-in sink and cupboard that is regarded as an universal option these days, and this has extensively been applied to kitchen system throughout the world after the repetitive development in America, Sweden and Switzerland. And improved kitchen of Park Gil-Yong which was influenced by rationalism introduced from the house improvement campaign and the opening of a port which were progressed in Korea in $1919{\sim}1930$ is the first stand-up kitchen which improved the inefficiency of Korean conventional kitchen. The purpose of this study is to understand the change aspect of kitchen through the rationalization in each country by comparing the introduction background of the times, change of space for residence and kitchen, and the characteristics of kitchen plan which had influence at the turning point on the kitchen in Korea, Europe on the side of efficiency at the same period, take into consideration of our residing-culture which has rapidly been changed between tradition and modernity, and to see the direction of kitchen design which copes with the unique residential environment.

일본 패션이 현대 패션에 미친 영향-(1980년대 이후를 중심으로)- (Study on the Influence that the Japanese Fashion has had on the Contemporary Fashion(Focusing on the since 1980s))

  • 정성혜
    • 복식
    • /
    • 제25권
    • /
    • pp.21-39
    • /
    • 1995
  • By 1980, there are two main flows in the world fashion. One is the traditional Paris fashion by Houte Couture, and the other is the American casual fashion by mass production. However, the appearance of Japanese designers and their new styles on the stage of Paris fashion have had a strong influence on the change of the world fashion since 1980s. So, the purposes of this study were first to research the process, the background and the power which let the Japanese stand and suc-ceed in the stage of Paris fashion, second to research on the Fashion World and Fashion Trend from the beginning of 1980s to present (1994). The results were as follow ; Hanae Mori and Kenzo were the pioneers who let the West know the existence and the level of Japanese fashion. Issey Miyake was the new innovator in the 20th century Fashion. and became the foundation of the New Wave Fashion in 1980s. Rei kawakubo completed the philosophy of beauty by the imperfection and has led the Postmodernism in the Fashion. The constant efforts of the these Japanese designers have inspired the orientalism and Art-to Wear, showed up the new construction and material in clothing by layering and drap-ing and stimulated the traditional Paris fashion to become popular, casual and diverse. The success of Japanese designers and the boom of Japanese fashion were not only the effort of individuality but also the power of economics, the spirit of cooperation and the affection to the culture and tradition on the background. The New Wave fashion by Japanese designers in the beginning of 1980s have promoted the appearance of Avant-garde fashion in London, the new fashion spirit in Milano, and the various fashion styles of different sections in the West and East. Finally, it becomes popular in 1990s and leads the fashion spirit in the end of 20th century.

  • PDF

Distribution properties of Phragmites australis and Phacelurus latifoilus in the tidal-flat of Suncheon Bay

  • Min, Byeong-Mee
    • Journal of Ecology and Environment
    • /
    • 제38권1호
    • /
    • pp.57-65
    • /
    • 2015
  • A natural mixed stand of Phragmites australis and Phacelurus latifolius was studied to clarify the distribution properties in a microsite in a tidal flat of Suncheon Bay. The height, density, and biomass of the shoots, as well as the biomass of the root system, were monitored for both species along with the altitude on a mound from June 2010 to October 2013. Firstly, the mean height and dry weight of both species were similar during the growth season. However, individual variations of the sizes of plants in the same species were noticeable. Secondly, the density and dry weight per unit area of P. latifolius increased, but that of P. australis decreased with the altitude on the mound. Thirdly, the root system (rhizomes and roots) of P. latifolius was mostly located in the upper layer (up to 20 cm depth), while that of P. australis was in the lower layer (over 70 cm depth) of the sediment. The roots of P. australis penetrated to the lower parts of the water table, while the roots of P. latifolius did not make contact with free water of the sediment. Fourthly, the removal of the shoot in the early growth season led to a visible reduction of biomass in the late growth season. The reduction rate was larger in P. latifolius than in P. australis. Lastly, in the area where the mound was removed, the density of P. australis increased in the first two years (2010-2011) and was highly sustained inthe last two years (2012-2013). However, the density of P. latifolius was low, and this plant was distributed at the edge of the mound only.

MANET 환경에서 MD5를 이용한 보안 라우팅에 관한 연구 (A Study on Security Routing using MD5 in MANET Environments)

  • 이철승;정성옥;이준
    • 한국정보통신학회:학술대회논문집
    • /
    • 한국해양정보통신학회 2008년도 추계종합학술대회 B
    • /
    • pp.728-731
    • /
    • 2008
  • 최근 독립된 네트워크의 구성 및 다양한 컨버전스 디바이스간 상호연결에 대한 요구로 MANET의 연구는 IETF MANET WG, Bluetooth, HomeRF WG에서 활발하게 진행되고 있으며, 유비쿼터스 컴퓨팅 활용은 많은 주목과 고도의 성장을 보이고 있다. MANET에 참여하는 MN들은 호스트와 라우터 기능을 동시에 수행하여 네트워크 환경설정이 쉽고 빠른 대응력으로 임베디드 컴퓨팅에 적합하지만 MN의 이동성으로 인한 동적 네트워크 토폴로지, 네트워크 확장성 결여 그리고 수동적 능동적 공격에 대한 취약성을 지니고 있어 지속적인 보안 서비스를 관리할 수 없다. 본 연구는 경로탐색 및 경로설정을 하는 라우팅 단계에서 악의적인 노드가 라우팅 메시지를 위 변조 하거나 적법한 MN으로 위장하는 공격을 방지하기 위해 AODV 라우팅 프로토콜에 MD5를 적용한 해시된 라우팅 프로토콜을 이용하여 안전성과 효율성을 향상 시켰다.

  • PDF