• Title/Summary/Keyword: Lee Ha-Bok

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Analysis of Noise Reduction Performance for Noise Cut Transformer (Noise Cut Transformer의 노이즈 억제성능 분석)

  • Lee, Jae-Bok;Huh, Chang-Su;Lee, Ki-Chul;Myung, Sung-Ho;Ha, Tae-Hyun
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1784-1786
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    • 1996
  • It is necessary to eliminate the broad band noise which frequency is in a few kHz to MHz in the AC line to supply the power to electrical and electronic control equipments. Because this kind of noise could damage the device or could be a source of malfunction, many devices like a filter and surge suppressor are developed to cut off the noise. But those device could not disconnected from the power line, so it remain some problem and on be used in limited area, In this paper, we present performance test results NCT(noise Cut Transformer) with excellent performance for reducing the high frequency noise and surge existing in the power line.

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Three-Dimensional Electric Field Calculation around Substation Busbars Using Adaptive Technique (적응적 기법을 이용한 전력소 모선하의 3차원 전계분포 해석)

  • Myung, Sung-Ho;Lee, Byeong-Yoon;Park, Jong-Keun;Kim, Suk-Won;Kim, Eung-Sik;Lee, Jae-Bok;Ha, Tae-Hyun
    • Proceedings of the KIEE Conference
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    • 1996.07c
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    • pp.1892-1894
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    • 1996
  • This paper presents optimal charge arrangement through potential error analysis. In order to decide the number of charges per conductor for a large system, adaptive simulation charge arrangement technique has been proposed. "Grouping" technique which means to divide analysis domain into two groups has been described through field error analysis. By this method, the size of matrix to calculate E field at a calculation point is reduced remarkably. The proposed method is applied to the electric field calculation around the Substation busbars.

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Evaluation of Restoration Capability in Radial Primary Distribution System (배전계통의 복구능력 평가방법)

  • Lim, Seong-Il;Ha, Bok-Nam;Lee, Jung-Ho;Cho, Nam-Hun;Lee, Seong-Jae
    • Proceedings of the KIEE Conference
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    • 1999.11b
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    • pp.267-269
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    • 1999
  • One of the main jobs of the operators is to make it sure to have a service continuity in a fault situation. This paper proposes a restoration index which indicates the restoration capability of the feeder in case of a fault. A necessary and sufficient condition for a feeder to have 100% restoration of the outage is also described.

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RE(Radiated Emission) Characteristics of Partial Discharge on Stator Winding for Rotating Machines (회전기 고정자 권선의 부분발전 방사특성)

  • Kang, Dong-Sik;Hwang, Don-Ha;Lee, Ki-Chang;Lee, Jae-Bok;Kim, Yong-Joo
    • Proceedings of the KIEE Conference
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    • 2005.07c
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    • pp.2115-2117
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    • 2005
  • 회전기기인 고압 전동기 및 발전기의 고정자권선에서 나타나는 운전중 부분방전 진단을 위한 방법의 하나로 비접촉식 센서를 이용한 부분방전 측정에 관한 연구가 최근 들어 활발히 진행되고 있다. 그러나 이들 권선에서 나타나는 부분방전의 방사특성에 대하여 정확한 측정이 국내에서 체계적으로 검토된 실적이 없는 실정이다. 본 논문에서는 회전기 고정자권선의 부분방전 현상을 측정하는데 이용될 비접촉식 부분방전 진단센서를 개발함에 있어서 필요한 측정 주파수대역을 선정하는데 이용하고자, 여러 종류의 고정자 권선을 대상으로 전압을 인가하여 발생되는 부분방전의 펄스의 방사특성 및 잡음특성을 실험실적으로 측정하여 고찰하였다.

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Distributed Restoration System Considering Security based on Multi-Agent (보안 기능을 고려한 Multi-Agent 기반의 분산형 정전복구 시스템)

  • Lim, Il-Hyung;Lim, Sung-Il;Choi, Myeon-Song;Hong, Sug-Won;Lee, Seung-Jae;Kwon, Sung-Chul;Lee, Sung-Woo;Ha, Bok-Nam
    • Proceedings of the KIEE Conference
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    • 2007.07a
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    • pp.27-28
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    • 2007
  • 본 논문은 배전계통을 운영함에 있어서 배전자동화 시스템의 가장 중요한 기능인 정전복구 기능에 대해서 현재의 중앙집중 방식에서 분산형으로 보다 효율적인 처리를 위한 알고리즘을 제안하였다. 분산형으로 처리하기 위하여 단말장치들을 Intelligent 기능에 능동 자율학습 기능을 보완할 수 있는 Multi-Agent 기법을 알고리즘에 도입하였다. 기존의 agent 기법을 응용한 연구는 적용 대상이 불분명한데 반해 본 논문에서는 적용 대상도 분명하고 현재 계통에도 바로 적용이 가능한 알고리즘을 제안하였다. 또한 Multi-Agent 기반 분산형 정전복구 시스템의 약점이라 할 수 있는 통신망 보안에 대해서 위협사례들을 분석하고, 이 위협들에 대한 보안알고리즘 적용방안을 제시하였다. 본 논문에서 제시한 알고리즘들을 PC 기반으로 예제계통을 꾸며 그 성능을 입증하였다.

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Screening of Herbal Extracts to Reduce PAR-2 and Cytokine Expression Related to Atopic Dermatitis in Keratocytes (피부세포에서 아토피 피부염의 유발과 관련된 PAR-2 및 사이토카인의 발현을 감소시키는 한약재 탐색)

  • Park, Sun-Min;Lee, Jung-Bok;Kim, Da-Sol
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.25 no.2
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    • pp.270-274
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    • 2011
  • The prevalence of atopic dermatitis has markedly increased in recent years but the mechanism has not been clearly revealed. Recent study exhibited that atopic dermatitis was exacerbated by the increase of proteinase-activated receptor (PAR)-2 expression, which activated $I{\kappa}B$ kinase --> nuclear factor kappa B. Therefore, we determined whether the allergens of dust mites induced the expression of PAR-2, intercellular adhesion molecule-1 (ICAM-1, adehision molecule), interleukins (IL)-6 in HaCaT keratocytes and which herbal 1,3-butylene glycol extracts (Mori Cortex Radicis, Sanguisorba officinalis L., Arctium lappa Linne, Torilis japonica DC, Melia azedarach Linne var. japoinca Makino) suppressed their expression. Dust mite allergen increased PAR-2, ICAM-1 and IL-6 expression in HaCaT cells in a dose-dependent manner up to $3{\mu}g/mL$ but their expression reached the plateau over the dosages. The allergen ($3{\mu}g/mL$) also secreted more cytokines such as tumor necrosis factor (TNF)-${\alpha}$ and IL-6 into the media. Among five different herbal extracts ($50{\mu}g/mL$), Mori Cortex Radicis and Sanguisorba officinalis L. suppressed the PAR-2, ICAM-1 and IL-6 expression in HaCaT cells, which was activated by dust mite allergen ($3{\mu}g/mL$) and they also reduced the secretion of TNF-${\alpha}$ and IL-6 into the media. In conclusion, Mori Cortex Radicis and Sanguisorba officinalis L. can effectively reduce the prevalence and progression of atopic dermatitis by dute mite allergen.