• Title/Summary/Keyword: e-field distribution

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Quench Characteristics of YBCO Film for Current Limiting Using Magnetic Field

  • 박권배;최효상;김혜림;현옥배;황시돌
    • Progress in Superconductivity
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    • v.3 no.2
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    • pp.252-256
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    • 2002
  • We studied YBCO films for current limiting of the resistive type which utilizes a transition from superconducting to normal state caused by exceeding critical current. The films were deposited on sapphire substrates and covered by gold top layer. The current limiting element consists of 2 mm wide YBCO stripes connected in series. A serious problem in using YBCO films for current limiting is inhomogeneities caused by imperfect manufacturing. Therefore simultaneous quench is a difficult problem when elements for current limiting are connected in series. So some researchers have recently proposed using magnetic field and heating for simultaneous quench. We have measured extended exec trim field-current density(E-J) characteristics for current limiting elements of YBCO films in applied magnetic field of 0 - 130 mT. And we have investigated quench characteristics in current limiting elements and between elements of YBCO films in applied magnetic field. The result of the experiments show that the presence of applied magnetic fields induces uniform quench distribution fur the stripes in element at $50V_{rms}$, otherwise non-uniform quenches were observed. And simultaneous quenches between elements were investigated at $150V_{rms}$. We suggest that suppressing the critical current by increased fields due to fault current effectively forced the stripes of higher $J_{c}$(0) to quench, resulting in equalizing quench times.s.s.s.

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A Study on the Improvement of Warehouse Management System (WMS) in e-Trade (전자무역의 WMS 개선방안에 관한 연구)

  • Jeong, Boon-Do;Kim, Jang-Ho
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.11 no.4
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    • pp.641-647
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    • 2007
  • It has been said that Warehouse Management System(WMS) in e-Trade has considerably contributed to improvement of distribution industry. However, in the aspect of management we have many technical problems such as transportation due to tremendous demands of online data. Therefore, for Korea to be a hub of distribution and information, this is the best time to prepare the foundation of Supply Chain Management(SCM) under Enterprise Resource Planning (ERP) the and make a good use of WMS. The purposes of this study are presented as follows: First, it is to examine the general flow process of WMS in each field of our e-Trade Second, it is to present problems and plans of improvements involved in WMS in e-Trade. In short, this study aims at presenting interpretative foundation of WMS in a practical viewpoint, not presenting technical directions of WMS.

Test field for the application of IEC 60364 in Korea (접지규정 IEC 60364의 국내 적용을 위한 실증시험장 구축)

  • Nam, Kee-Young;Choi, Sang-Bong;Ryoo, Hee-Suk;Lee, Jae-Duck;Jeong, Seong-Hwan;Kim, Dae-Kyung
    • Proceedings of the KIEE Conference
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    • 2005.11b
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    • pp.116-118
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    • 2005
  • IEC 60364-4-44 provides rules for the protection against the effects of conducted and radiated disturbances on electrical installations. Especially this standards deals with the protection of low voltage facility against the ground fault in the high voltage side of power distribution system. Many countries defines the regulations on the use and production of electrical facilities based on their own power system and technical references which are considered to be suitable for themselves. The background of circuit of IEC 60364 is based on the ungrounded system as most of European countries adopt. However, since domestic ground system is multi-grounding system different from European system, it is necessary to evaluate or prove the effect of the IEC 60364 for introducing and applying it to the domestic grounding system as a Korean standard. This paper presents the establishment of test field to get background data to introduce the IEC 60364 and to evaluate the standard is applicable or not to domestic rule for the protection against ground fault through the related test.

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AC Loss Calculation in High Temperature Superconductors Using Slab model (Slab모델을 이용한 HTS AC 손실의 계산)

  • 최세용;주진호;류경우;나완수
    • Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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    • 2001.02a
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    • pp.102-103
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    • 2001
  • In this paper we calculate the AC Loss in the superconducting slab carrying ac transport current. Magnetic diffusion equation for computation of the electric field and current distribution are based on Maxwell's equations and non-linear constitutive equation. The E-J characteristics of superconductor are applied to computation. We will present the result of the high-temperature superconductor case comparison with the slab of low temperature superconductor.

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Recent Progress of Freak Wave Prediction

  • Mori, Nobuhito;Janssen, Peter A.E.M.
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2006.11a
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    • pp.127-134
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    • 2006
  • Based on a weakly non-Gaussian theory the occurrence probability of freak waves is formulated in terms of the number of waves in a time series and the surface elevation kurtosis. Finite kurtosis gives rise to a significant enhancement of freak wave generation in comparison with the linear narrow banded wave theory. For fixed number of waves, the estimated amplification ratio of freak wave occurrence due to the deviation from the Gaussian theory is 50% - 300%. The results of the theory are compared with laboratory and field data.

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New Ramp-reset Waveform for Fast Addressing in AC-PDPs

  • Kim, Oe-Dong;Ahn, Byoung-Nam;Choi, Kwang-Yeol;Yoo, Eun-Ho
    • 한국정보디스플레이학회:학술대회논문집
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    • 2005.07a
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    • pp.643-646
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    • 2005
  • We present new ramp-reset waveforms that realize fast addressing in AC-PDPs. These waveforms distort the distribution of wall charges on the surface of a phosphor layer: hence, the enhanced electric field helps to ignite a cell faster. They also reduce the black luminance: the divide of erasing ramp down discharges into two parts, i.e. a surface discharge and a vertical discharge, makes lower luminance.

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Analysis of Electric Fields Inside GIS With Metal Impurity Using 3 Dimensional Surface Charge Method (일반 3차원 표면전하법을 이용한 금속 이물질이 유입된 GIS 내부의 전계 해석)

  • Kim, Y.J.;Min, S.W.;Kim, E.S.
    • Proceedings of the KIEE Conference
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    • 1999.07e
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    • pp.2117-2119
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    • 1999
  • In this paper, the electric fields inside GIS with metal impurity is analysed by the use of 3 dimensional Surface Charge Method. We find the metal impurity makes electric field distribution inside GIS non-uniform and causes breakdown of $SF_6$ gas in GIS.

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Does E-Banking Enhance Client Satisfaction in Saudi Banks?

  • SHADDADY, Ali
    • The Journal of Asian Finance, Economics and Business
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    • v.9 no.10
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    • pp.251-264
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    • 2022
  • This study explores e-banking variables that affect client satisfaction in the Saudi Arabian banking industry spanning three dimensions: reliability, security concerns, and efficiency, which were chosen as predictors of customer satisfaction in the e-banking industry. A field survey using a self-administered questionnaire as a data collection instrument was adopted to collect the required data from a convenience sample of 250 participants of Saudi banking customers. The overall fit of the hypothesized model was tested using linear regression to find the rate of the independent factors' impact on the dependent variable. The study's findings revealed that there is a statistically significant relationship between the three dimensions and customer satisfaction in Saudi e-banking, with the largest impact being that of reliability, followed by efficiency, and finally security concerns. Also, the study found there was a significant difference in reliability which was considered more important for Saudis and there was a significant difference in efficiency, which was considered more important by males. The findings of this study suggest that these three dimensions are instrumental in e-banking customer satisfaction and that banks can gain a competitive edge by providing better services in these dimensions to sustain and develop their performance in the increasingly globalized banking industry.

Magnetic Field Distributions of Superconducting MRI Magnet in Insert Dewar (Insert dewar를 이용한 초전도 MRI 마그네트의 자장분포 평가)

  • Jin, H.B.;Oh, B.H.;Kwon, Y.G.;Oh, S.S.;Cho, J.W.;Ha, D.W.;Lee, E.Y.;Ryu, K.W.;Ryu, K.S.;Hahn, I.Y.;Nah, W.
    • Proceedings of the KIEE Conference
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    • 1995.07a
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    • pp.137-140
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    • 1995
  • This paper describes the test results of magnetic field distributions of superconducting MRI magnet in an insert dewar. To get a very high homogeneous magnetic field, various shim coils are installed besides the main magnet. The operating currents of each shim coils are obtained from the exact measurements of the magnetic field. In this paper, we report the test results of the magnetic field distribution measurements with various shim coils.

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Ecological Characteristics of Weed Species on Dry Field in the Eastern Region of Korea (한국 동부지역 밭잡초의 생태적 특성)

  • Cho, Kwang-Jin;Oh, Young-Ju;Lee, Wook-Jae;Choi, Jeong-Oh;Sohn, Soo-In;Kim, Myung-Hyun;Yang, Dong-Woo;Kim, Chang-Seok
    • Weed & Turfgrass Science
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    • v.4 no.3
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    • pp.188-198
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    • 2015
  • This study was conducted in order to investigate the distribution pattern of weeds and ecological characteristics on the dry field in the Eastern region of Korea. The weed species data were obtained from 12 regions in Gangwon-do and Gyeongsang-do. 150 taxa were recorded from three main distinguished habitats; inside of dry field (IDF), embankment around the end of dry field (EDF), levee slope of dry field (LS). The weed species of three different habitats were IDF 83 taxa, EDF 133 taxa and LS 105 taxa. The species showing higher rNCD value was Portulaca oleracea in IDF, Digitaria sanguinalis in EDF and Humulus japonicus in LS. Compositae was dominant family followed by Gramineae, Polygonaceae and Leguminosae. Life form was distinguished as Th-R5-D4-e and three different habitats showed the same results. Disturbance index was analysed as IDF 83.1%, EDF 68.4%, and LS 62.9%. Naturalized rate was analysed as IDF 28.9%, EDF 22.6%, and LS 20.0%. These results indicate that the weeding management, land use intensity, and human interference effect on the distribution index and naturalized rate of weed.