• Title/Summary/Keyword: SIS

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Fabrication of AlN Powder by Self-propagating High-temperature Synthesis I. Synthesis of AlN Powder (자전고온 반응 합성법에 의한 AlN 분말의 제조 I.AlN 분말의 제조)

  • 신재선;안도환;김석윤;김용석
    • Journal of the Korean Ceramic Society
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    • v.33 no.9
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    • pp.961-968
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    • 1996
  • The aluminum nitride was synthesized by the self-propagating high-temperature synthesis(SHS). The synthe-sis was used aluminum powder mixed with AlN powder as reactant and the control factors affected to synthesis were considered compact density pressure of reaction gas AlN diluent content and aluminum powder size. The SHS reaction conducted with a reactant containing 50% AlN diluent under 0.8MPa nitrogen gas pressure yielded a complete conversion of aluminum powder to AlN powders. The size and purity of AlN produced were found to be comparable with that of AlN produced by the carbothermal nitrogen method.

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DABCO-Catalyzed Green Synthesis of 2-Hydroxy-1,4-diones via Direct Aldol Reaction of Arylglyoxals in Water

  • Saraei, Mahnaz;Eftekhari-Sis, Bagher;Mozaffarnia, Sakineh
    • Journal of the Korean Chemical Society
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    • v.57 no.2
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    • pp.252-259
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    • 2013
  • A green and simple method to synthesize of 1,4-diketones via aldol reaction of arylglyoxals and ketones such as 1-(4-methoxyphenyl)-2-propanone, deoxybenzoin and substituted acetophenones in the presence of a catalytic amount of DABCO in water at room temperature has been reported. Corresponding 2-hydroxy-1,4-diones were obtained in moderate to high yields with simple separation of obtained solid from reaction mixture and recrystallization.

Light Regulated Plant Gene Expression (빛에 의한 식물 유전자의 발현)

  • 한태룡
    • Proceedings of the Botanical Society of Korea Conference
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    • 1987.07a
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    • pp.63-79
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    • 1987
  • Light regulates a variety of genes in higher plants. The expression of light-induced plant genes is regulated at the level of transcription via red- light photomorphogenic receptor, phytochrome, as well as unknown blue light photoreceptor(s). Ribulose-5-phosphate carboxylase/oxygenase (Rubisco) small subunit (SSB) and light harvesting chlorophyll a/b (Cab) protein are those of the best understood genes regulated by light. 5'-upstream flanking sequence (- -400) of Rubisco SSB and Cab genes sis known as a light responsive, enhance-like element. It responses to red and blue light in transgenic plant system as a tissue specific manner. Phytochrome gene is also regulated by light. In contrast to most of the light regulated plant genes, it is negatively controlled by red light. Search for the cis- and trans-acting factors responsible for the light signal is in progress to understant photomorphogenesis and development in higher plants.

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The Causes, the Process, and the Consequences of Downsizing Information Systems (다운사이징 정보시스템의 원인, 과정, 결과)

  • 박관희
    • The Journal of Information Technology and Database
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    • v.1 no.2
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    • pp.25-35
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    • 1994
  • Downsizing IS is rapidly emerging as one of new information systems of the 1990s that involves (1) the cost reduction, (2) the reduction of MIS staff, and (3) the transfer of IS functions to end - users. As downsizing is relatively new information systems, little is known about the causes, the process, or the consequences of downsizing. Case study was chosen as the research methodology of this study. The downsizing IS of Namsun Aluminum Co. Ltd. in Taugu City was chosen for the exploratory case study. The detailed and qualitative analyses to Namsun were performed with the use of observation, participation, and interview techniques. Consequently, the causes, the process, and the consequences of Namsun's downsizing were analyzed and discussed. As for the main cause, downsizing was started with the purpose of cost reduction. The important consequences of downsizing IS are as follows : (1) About 700 million won reduction in the cost of initially developing the downsizing was achieved. (2) Downsizing is performing Namsun's mission critical applications. (3) Namsun's downsizing could be considered to be SIS(strategic information systems).

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A Study on the Characteristics of Interior Design in De Stijl (De Stijl 에 있어서의 실내디자인 특성에 관한 연구)

  • 한영호
    • Korean Institute of Interior Design Journal
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    • no.8
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    • pp.16-22
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    • 1996
  • In terms of modern design history, De Stijl movement had continued as one of influential groups by 1931, and it attempted to pursue universial reality that combined painting and architecture, seeking a new style based on Neo-Plasticism and succeeded the nineteen century's Art and Craft movement and Art Nouveau. Especially, the De Stijl movement provided 1920's rationalism with new space pattern and its ideas greatly affected the Bauhaus movement such as Walter Gropius or Mies van der Rohe. De Stijl's utopian idea that claimed on the conformity of art and life contributed modernism movement combined with scientific and rational view, and even now experts its lasting power with the concept of time and space free from simple cube in modern architecture and interior design. The tue meaning of the De Stijl movements is that is sis the basis of general ideas, and the change of modern architecture is based on this modern styled foundation. It may be the unchangeable fact like Russell Hitchocok says, "The architectural style and pattern which everyone admitts its importance has the value of living."

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A CLB-based CPLD Low-power Technology Mapping Algorithm considered a Trade-off

  • Youn, Choong-Mo;Kim, Jae-Jin
    • Journal of information and communication convergence engineering
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    • v.5 no.1
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    • pp.59-63
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    • 2007
  • In this paper, a CLB-based CPLD low-power technology mapping algorithm considered a Trade-off is proposed. To perform low-power technology mapping for CPLDs, a given Boolean network has to be represented in a DAG. The proposed algorithm consists of three steps. In the first step, TD(Transition Density) calculation has to be performed. Total power consumption is obtained by calculating the switching activity of each node in a DAG. In the second step, the feasible clusters are generated by considering the following conditions: the number of inputs and outputs, the number of OR terms for CLB within a CPLD. The common node cluster merging method, the node separation method, and the node duplication method are used to produce the feasible clusters. In the final step, low-power technology mapping based on the CLBs packs the feasible clusters. The proposed algorithm is examined using SIS benchmarks. When the number of OR terms is five, the experiment results show that power consumption is reduced by 30.73% compared with TEMPLA, and by 17.11 % compared with PLA mapping.

An Experimental Study on the Low-Temperature deformation strength Properties of Asphalt Mixtures (아스팔트 혼합물의 저온변형강도 특성에 관한 실험적 연구)

  • Kim, In-Joong;Jeong, Yong-Hwi;Kim, Kyeong-Jin;Lee, Seung-Yong
    • Proceedings of the Korean Society of Disaster Information Conference
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    • 2017.11a
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    • pp.243-244
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    • 2017
  • 아스팔트 포장체의 안정적인 품질확보를 위해서는 아스팔트 바인더 자체가 부착력과 탄성력 확보는 물론 저온에서도 충분한 변형능력이 확보되어야 한다. 본 연구는 저온에서의 아스팔트 바인더의 성능개선을 목적으로 기존에 상용화되고 있는 아스팔트 바인더와 고분자계 GMA 수지(SIS, Styrene Isoprene Styrene)를 기반으로 제조된 바인더의 성능을 비교하기 위해 변형강도시험(Kim Test)을 실시하였다. 시험결과, 동절기 취성적인 파괴로 손상을 입은 도로의 보수에 있어서 SIS가 첨가된 아스팔트 혼합물은 충분한 보수효과가 기대될 것으로 판단된다.

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A Numerical Analysis on Thermal Stratification Phenomenon by In-Leakage in a Branch Piping

  • Park Jong-Il
    • Journal of Mechanical Science and Technology
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    • v.19 no.12
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    • pp.2245-2252
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    • 2005
  • Thermal stratification in the branch piping of power plants can be generated by turbulent penetration or by valve leakage. In this study, a numerical analysis was performed to estimate the thermal stratification phenomenon by in-leakage in the SIS branch piping of nuclear power plant. Leakage rate, leakage area and leakage location were selected as evaluation factors to investigate the thermal stratification effect. As a result of the thermal stratification effect according to leakage rate, the maximum temperature difference between top and bottom of the horizontal piping was evaluated to be about 185K when the valve leakage rate was about 10 times as much as the allowed leakage rate. For leakage rate more than 10 times the allowed leakage rate, the temperature difference was rapidly decreased due to the increased mixing effect. In the result according to leakage area, the magnitude of temperature difference was shown in order of $3\%,\;1\%\;and\;5\%$ leakage area of the total disk area. In the thermal stratification effect, according to the leakage location, temperature difference when leakage occurred in the lower disk was considerably higher than that of when leakage occurred in the upper disk.

Trends and Technology Ana17sis of XKMS(Xml Key Management Specification) (XKMS(Xml Key Management Specification)동향 및 기술 분석)

  • 김세영;이석래;박정환;신동일
    • Proceedings of the Korean Information Science Society Conference
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    • 2001.10a
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    • pp.772-774
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    • 2001
  • 최근 XML(eXtensible Markup Language)이 인터넷 전자 상거래와 데이터 전송 및 검색 부문에서 광범위하게 이용됨에 따라, XML 문서에 대한 보안과 표준화 문제가 대두되고 있다. XML을 이용한 각종 데이터 및 문서는 웹 상에 존재하게 되며, 가상공간에서 문서적 처리는 제 3자에 의해 위조나 변경이 가능하다. 이에 데이터 및 문서를 보호하는 일은 현재 필수적인 사안이며, XML 문서 보안에 대한 연구 개발 또한 활발히 진행되고 있다. 최근 Microsoft와 Verisign, Webmethods등 3개사는 XML기반 차세대 PKI(Public Key Infrastructure)기술인 XKMS(Xml Key Management Specification)를 개발하였으며, XKMS 표준화 작업에 휴렛패커드(HP), 불티모어, IBM, 퓨어에지솔루션스, 로이터 등이 참여하고 있다. 이에 본 논문에서는 XKMS의 표준화를 진행중인 표준화 단체의 XML 보안동향을 파악하고, XKMS의 내부 구조 및 전반적인 기술을 분석한다.

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Mobile HD Broadcasting Field Test for ATSC 3.0 Transmitting/Receiving Systems (ATSC 3.0 송수신 시스템을 위한 이동 HD 방송 필드테스트)

  • Seo, Jae Hyun;Lee, Bong Ho;Kim, Heung Mook;Kim, Yongsuk
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 2018.06a
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    • pp.67-68
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    • 2018
  • 국내에서는 세계최초로 2017 년에 지상파 UHD 본방송 서비스가 시작되었다. 지상파 UHD 방송은 ATSC 3.0 표준을 기반으로 고정 4K UHD 및 이동 HD 의 동시서비스가 가능하다. 기존의 DTV 와 이동방송인 지상파 DMB 를 대체하여 4K UHD 와 이동 HD 방송을 한 개의 주파수 대역에서 통합한 UHD 모바일 서비스가 가능하게 되었다. UHD 모바일 시범서비스를 앞두고 ATSC 3.0 송수신 시스템을 구축하여 실방송 환경에서 필드테스트 결과를 살펴보고 미래의 이동방송 서비스에 대해 전망해보고자 한다.

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