• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.2208-2209
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• 2008

최근 국제 표준 및 규격의 국내 도입에 따라 다양한 접지 방식에 대한 안전성과 신뢰성이 요구되고 있으나, 현재 국내 규정은 국제 규격과 부합되지 않는 측면이 있다. 따라서, 국내 건축물의 접지시스템에 대한 정확한 현장 실태를 바탕으로 국내 실정에 맞는 접지시스템의 개발이 요구되고 있다. 본 논문에서는 아파트, 공장, 상가, 학교 등의 신축 건물에 시설된 접지방식 및 등전위 본딩 실태 등을 현장 조사를 중심으로 분석하였다. 접지실태조사는 접지방식, 접지단자의 접속방식, 공결방식, 접지요소간의 접속방식 등을 분석하였으며, 등전위 본딩 실태조사는 IEC 60364에 규정된 방법을 근거로 계통외 도전성 부분과 기기외함의 연속성을 평가하였다.

• Journal of the KSME
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• v.33 no.9
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• pp.793-802
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• 1993

이 글에서는 부 온도저항계수를 갖는 탄소파이버를 열선으로 이용하고 이를 구동한는 증폭회로의 구성에 관한 연구, 3차원 속도측정용 열선프로브의 접지단자를 3개의 열선이 공통으로 사용하는 공통접지 삼축 열선프로브와 유속계의 특성에 대해 고찰한다. 또한 과열비가 다른 두 개의 저 온도형 열선 유속계를 이용하여 유동장의 온도와 속도를 동시에 측정한는 방법과 임의 형태의 유체온도정보를 이용한 열선유속계의 일반적인 온도보상방법에 관하여 논의하여 열선유속계의 원리와 그 응용 등을 간단히 설명함으로써 관심 있는 분들의 이해를 돕고자 한다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.6
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• pp.66-71
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• 2003

Electronic equipments made from integrated circuits and small-sized semiconductors is protected by surge protective devices(SPDs) such as ZnO varistors, Zener diode and gas discharge tube from lightning overvoltages. However the clamping voltage of SPDs is greatly influenced by the method of installing the SPDs. In this paper, the protective effects of SPDs according to types of system groundings were experimentally investigated. The separate grounding is a particularly undesirable way to install SPDs. The effectiveness of the common grounding point for ZnO varistors is more pronounced than that for gas discharge tubes. The common grounding at the terminal of SPDs is recommended as a best method of installing SPDs.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.20 no.11
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• pp.1130-1137
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• 2009

This paper proposes a new clock routing design for suppressing clock harmonic effects in a Printed Circuit Board (PCB) for a terrestrial Digital Multimedia Broadcasting(DMB) system. Typical crystal reference frequencies that are widely used in DMB tuners are 16.384 MHz, 19.2 MHz, 24.576 MHz. When the high-order harmonic components of these reference frequencies fall near the RF channel frequencies, receiver sensitivity of the tuners is seriously degraded. In this work, we propose a new clock routing design in order to address the clock harmonic coupling issue. The proposed design incorporates two inductors for isolating the clock ground from the main ground, and adopts a new strip line-style routing instead of the conventional microstrip line style routing to minimize the overlap area with the main ground. As a result, the RF sensitivity of the T-DMB tuner is improved by 2 dB.

• Proceedings of the Korea Institute of Fire Science and Engineering Conference
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• 2013.04a
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• pp.188-189
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• 2013

본 논문에서는 산업현장과 교육시설에서의 가정용 소형 단상변압기의 규격품 사용 여부와 운영상의 안전성 실태를 분석하였다. 전기용품 안전 관리법에 따른 법정인증을 받지 않은 제품이 5개 조사되었으며, 단자 체결형 변압기의 경우 전원선 접속 불량(헐거움), 설치 및 고정 불량, 접지 미체결(누락), 전압조정 핸들 파손, 변압기 상부 가연물 방치가 주요 불합리 항목으로 조사되었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.6
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• pp.67-74
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• 2010

Most of domestic low-voltage consumers are supplied from the TN-C system of KEPCO, but their load installations have established according to the national statutory standard for electrical installations based on the TT system. In this work, to propose the proper system earthing arrangements of ensuring the protection of information-technology equipment against lightning surges, the protection performance of TT and TN systems against lightning surges was investigated. As a result, when lightning surge was injected to the neutral line of distribution system, the potential difference between the equipment earth terminal and neutral point of low-voltage mains in a TT system was significantly raised. The TT system is not advised due to the risk of damage to the sensitive computer equipment. Main equipotential bonding is an important requirement for protection of low-voltage installations against lightning surges. The TN system provides the best means to reduce the incoming lightning surges through the neutral line of low-voltage service systems. In addition, It is highly recommended to install the additional earthing at the service position of low-voltage consumers.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.16 no.8 s.99
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• pp.835-841
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• 2005

In this paper, a novel sized-reduced CPW(Coplanar Waveguide) balun is proposed. It has a crossing structure between signal line and ground planes of CPW transmission line for the $180^{\circ}$ phase inversion. The$3{\lambda}/4$ CPW transmission line is reduced to ${\lambda}/4$ in physical length while the electrical length is preserved to $270^{\circ}$ by the $180^{\circ}$ phase inverting structure, while the previous balun by Lim et at. has a long $3{\lambda}/4$ transmission section to from the Wilkinson divider structure having out of phase between output ports. In addition, the measured data which show the crossing structure has the wanted $180^{\circ}$ phase change is presented in this work.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• v.9 no.2
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• pp.693-696
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• 2005

Parallel and cross of the electrical power and telecommunication network is become accelerated, because telecommunication equipments are constructed according to road for efficient maintenance of domestic telecommunication network. The electrical power network can generate an electrostatic induction, and is itself transmission medium from electrical transient phenomenon such as lighting. So, transient phenomenon of lightning surge is induced to telecommunication network, and then it is damaged by connecting between electrical ground of electrical power network and telecommunication network. In this study, we found that cut-off of return path current by separate distance between electrical ground of electrical power network and telecommunication network, and cut-off of electrostatic induction voltage by grounding unused leads of both terminals of the electrical and telecommunication network have good effect as the protection methods of telecommunications network from electrical transient phenomena.

• Proceedings of the KIEE Conference
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• 2004.07c
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• pp.2049-2051
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• 2004

Bow-tie 마이크로스트립 패치형태로 초광대역 안테나를 설계 제작하였다. 보다 광대역화된 특성을 얻기 위해 급전구조 변화와 반원형태의 기생페치를 추가하였다. 제작된 안테나는 입력단자 부분의 접지면을 전제하고 VSWR${\leq}$2를 기준으로, 슬롯형태가 아닌 패치형태로도 2.3GHz${\sim}$5.5GHz까지 대역폭비 2.4 : 1의 초광대역 특성을 나타냈다. 또한, 수평 단면 패턴에 대하여 넓은 주범을 가지며, 전 대역에서 안정된 방사패턴을 유지 하였다.

• 한국초전도학회:학술대회논문집
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• v.9
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• pp.71-74
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• 1999

We have fabricated high-T$_c$ superconducting YBa$_2Cu_3O_{7-{\delta}}\;/SrTiO_3/\;YBa_2Cu_3O_{7-{\delta}}$ (YBCO/STO/YBCO) multilayer structure on (001) $SrTiO_3$ substrate by using pulsed laser deposition technique for applying to ground plane of single flux quantum digital circuits. In this structure, the top and bottom YBCO layers were connected through the holes in the STO insulating layer. The critical temperature of the two YBCO layers connected each other was 86 K after annealing at 500 $^{\circ}C$ in $O_2$ atm for about 60 hr. This result shows that the annealing process is very important fabricating YBCO/STO/YBCO multilayer structure An experiment to optimize the fabrication process of YSCO/ST0/YBCO multilayer structure with good quality is in progress.