• Title/Summary/Keyword: Breaking time

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New Arc Chamber to Improve Breaking Capacity (차단용량 향상을 위한 신소호 구조)

  • Park, Jin-Young;Cho, Hea-Yong
    • Journal of Advanced Marine Engineering and Technology
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    • v.36 no.2
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    • pp.321-326
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    • 2012
  • The mechanism unit, arc chamber and trip unit are imperative components of MCCB which will decide the level of performance of MCCB. Among them, Arc chamber unit is used for extinguishing arc rapidly of fault current and induce the arc inside of grid. At that time inducing arc will split into parts and cooled rapidly so the arc would disappear. This paper suggests new arc chamber unit to improve arc extinguishing performance with optimum design and are applied to actual products based on the results.

Tracing March 2004 and December 2005 Heavy Snowfall of South Korea Using NOAA AVHRR Images

  • Shin, Hyung-Jin;Park, Geun-Ae;Kim, Seong-Joon
    • Journal of The Korean Society of Agricultural Engineers
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    • v.49 no.3
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    • pp.33-40
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    • 2007
  • This study is to grasp and analyse the temporal and spatial distribution of record-breaking heavy snowfall rarely occurred in the middle and southwest region of South Korea during March of 2004 and December of 2005 respectively. Snow cover area was extracted using the channels 1, 3 and 4 of NOAA AVHRR images and the snow depth distribution was spatially interpolated using snowfall data of meteorological stations. Using administration boundary and Digital Elevation Model from 1:5,000 NGIS digital map, the snowfall impact was assessed spatially and compared with the reports at that time. The damaged area by heavy snowfall over 15 cm snow depth could be identified successfully within the spatial extent of snowfall area extracted by NOAA AVHRR image.

Design and Implementation of CMS using MVC Framework (MVC 프레임워크 기반의 CMS 설계 및 구현)

  • 이준희
    • Proceedings of the Korea Contents Association Conference
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    • 2003.11a
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    • pp.157-160
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    • 2003
  • Web services can be invoked statically using a WSDL service interface and service implementation documents, or dynamically by retrieving the service type definitions and the service implementation via UDDI. But until now, couldn't do both at the same time. The Model View Controller pattern(MVC) supports both dynamic and static Web services. The MVC paradigm is a way of breaking an application, or even just a piece of an application's interface, into three parts: the model, the view, and the controller. Object-oriented methodologies have been applied to developing internet applications for increase reuse and expandability. I supposed a effective multimedia CMS(Contents Management Systems) using MVC.

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Risk Assessment for Pneumatic Braking of EMU (철도차량 제동장치의 위험도 평가)

  • Lee, Sung-Kwun;Kim, Jong-un;Koo, Jeong-Seo
    • Journal of the Korean Society of Safety
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    • v.30 no.5
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    • pp.114-122
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    • 2015
  • FMEA and FTA have been widely applied to the safety studies for railway systems respectively. But it would be more effective to use these two methods at a same time because these are complementary. This article suggests a FMEA-FTA combined analysis technique to evaluate the risk for railway systems. A FMEA-FTA combined risk evaluation model and process are proposed and a case study is dealt with for PBU(Pneumatic Breaking Unit), a major subsystem of a railway vehicle.

TRACING MARCH 2004 AND DECEMBER 2005 HEAVY SNOWFALL OF SOUTH KOREA USING NOAA AVHRR IMAGES

  • Shin, Hyung-Jin;Park, Geun-Ae;Kim, Seong-Joon
    • Proceedings of the KSRS Conference
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    • v.1
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    • pp.110-113
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    • 2006
  • This study is to grasp and analyse the temporal and spatial distribution of record-breaking heavy snowfall rarely occurred in the middle and southwest region of South Korea during March of 2004 and December of 2005 respectively. Snow cover area was extracted using the channels 1, 3 and 4 of NOAA AVHRR images and the snow depth distribution was spatially interpolated using snowfall data of meteorological stations. Using administration boundary and Digital Elevation Model from 1:5,000 NGIS digital map, the snowfall impact was assessed spatially and compared with the reports at that time.

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Adsorption of Hg(I), Pb(II), and U(VI) ions using from Fruits of Schizandra Chinensis (오미자를 이용한 Hg(I), Pb(II), U(VI) 이온들의 흡착)

  • Kim, Kwan-Chun;Kim, Joon-Tae
    • Journal of environmental and Sanitary engineering
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    • v.22 no.1 s.63
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    • pp.29-35
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    • 2007
  • This study was examined adsorption ability of heavy metal Hg(I), Pb(II), and U(Vl) ion use of fruit from schizandra chinensis, The fruits of schizandra chinensis sample used breaking into fragments $50{\sim}100$ mesh. The sample solution was mixed fruits of schizandra chinensis and heavy metal ion. Each heavy metal ion of into solution was quantum analysis with ICP-AES. As the result, each condition of maxium adsorption ability of heavy metal ion was high in the range of pH 5-7, adsorption time was about 15 minutes, and the optimum temperature was $100^{\circ}C$. The heavy metal ion was increased adsorption in order of increasing concentration and in ethanol solution better than in aqueous solution.

The Effect of HCl-AlCl3(Catalyst) Concentrations on Acid Hydrolysis of Ricestraw Cellulose (염산(鹽酸)과 촉매 AlCl3의 농도가 볏짚 Cellulose의 산가수분해(酸加水分解)에 미치는 영향)

  • Lee, Byung-Guen
    • Journal of the Korean Wood Science and Technology
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    • v.20 no.1
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    • pp.23-27
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    • 1992
  • 81.9% of the cellulose delignified by acetosolv process was hydrolyzed in HCl-$AlCl_3$ hydrolysis system when $AlCl_3$ was used as catalyst in breaking down of glycosidic bond of cellulose. It was well compared that the HCl hydrolysis system without $AlCl_3$ as catalyst showed only 60~61% of the hydrolyzed yield. Also monosaccharide yield including glucose clearly increased when $AlCl_3$ was use. When concentration of HCl and $AlCl_3$ was increased, the hydrolyzed monosaccharide was increased within certain range. The monosaccharid yield out of the hydrolyzed reached 55.4% at optimum conditions which were identified as 20% of Hel solution, 0.03 Mol of $AlCl_3$, $120^{\circ}C$ of reaction temperature and 7 hours of reaction time employed in this study.

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Effect of NaCl on Germination of Artiplex gmelini and Pharagmites communis (갈대 및 가는갯능쟁이의 발아에 미치는 NaCl의 효과)

  • 김관수
    • Journal of Plant Biology
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    • v.28 no.3
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    • pp.253-259
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    • 1985
  • The results of the conducted experiment obtained basic data on seed germination for Phragmites communis and Atriplex gmelini were; Seed germination was not influenced till 0.5% NaCl, but at over 1.0% NaCl it dropped remarkably. The germination limit fro degree of NaCl was 2.0% in Phragmites communis. Atriplex gemelini was 2.5% and in accordance with the increase of the degree of NaCl. Germination speed showed a negative correlation being highly significant and the germination period lengthened. Compared with growing top plants, growth of roots was largely influenced by a high degree of NaCl. In accordance with the rise of temperature, the germination rate, and speed of both plants remarkably increased and the germination period was shortened. Ubride of Atriplex gmelini was germinated at the early days of picking but was not as the passing of the period. The seeds also did not germinated likewise Ubride. By a seedcoat breaking germination became 81%. During 20 min soaking treatment in conc H2SO4 seed germination possibility of 63% was known to be hard. Adequate soaking time in conc H2SO4 was 17.5 min.

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Design and Implementation of c-Commerce Portal of Small and Medium Enterprises for Marketing (중소기업 마케팅.유통 지원을 위한 협력상거래 포탈 설계 및 구현)

  • 안요찬;서중석
    • Journal of Information Technology Applications and Management
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    • v.11 no.1
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    • pp.175-187
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    • 2004
  • Many companies have integrated their internal processes with the aid of information technology. Now the focus is on interconnecting trading partners. Collaborative commerce (also known as c-Commerce) has a key role. It is not just about making it easier for business to communicate. It is about by breaking down barriers along the entire length of the supply chain. Some c-Commerce links are permanent, others get established when and where they are needed. c-Commerce is helping business in electronic supply chains to improve product delivery while cutting costs, to strengthen relationships and to reduce lead time. In this paper, we propose the concept of collaborative commerce, and design and implement Collaborative Commerce Portal (CCP) system of small and medium enterprise for marketing support. The technical definition of CCP is set of all technical elements can do collaborative commerce between small and medium enterprises with Internet or Internet. The target information of CCP includes usual and unusual information and all other information of companies used as process events. Through this, it enhances efficiency of business processes, core information sharing and marketing activation.

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Optimal Design of a Permanent Magnetic Actuator for Vacuum Circuit Breaker using FEM

  • Yoo Yong-Min;Kim Dae-Kyong;Kwon Byung-Il
    • Journal of Electrical Engineering and Technology
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    • v.1 no.1
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    • pp.92-97
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    • 2006
  • This paper presents the characteristic analysis and the optimal design of a permanent magnetic actuator (PMA) for a vacuum circuit breaker (VCB) using a two-dimensional finite element analysis. The purpose of this research about a PMA is to minimize the breaking time and the volume of the permanent magnet within the limits of the holding force and maximum current in the coil. The conjugate gradient method is used as an optimization algorithm. The node moving technique is iteratively implemented until the design variables of the PMA are optimized. In this paper, the optimal design of a PMA is accomplished to improve the conventional design methods.