• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2007.05a
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• pp.463-467
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• 2007

It is necessary to study the prevention and the management of electrical facilities because the electrical fault took place at the dust occurrence area due to environmental pollution. In particular, the dust accumulates easily on insulation material which is exposed an external long time. The leakage current brings out electrical fault after all. Also, it is need to variation of material and shape to repress a leakage current on electrical material. In this paper, we measured a leakage current on electrical material of facilities by dust, and in experiments the prevention to electrical fault was studied.

• International Commerce and Information Review
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• v.11 no.1
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• pp.485-515
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• 2009

In this study aims to research and analyze what are decision factors between a wholly-owned subsidiary and a international company cooperation in the internationalization process. From 57 primary studies found 26 observed variables for aggregation of effect size in the using "Fixed Effect Model" on this mata-analysis. The article also links the theories that are used in the literature, not considered in the most of primary studies, to the empirical results and recommends global management strategy which is needed for business practical affairs. According to the result, the meta-analysis suggests that the number of employees of a MNC, the geological and cultural differneces between the host country and home country, the country-specific international experience of the MNC and export intensity, the international product diversification, the market growth and the market size of the foreign operations, and resource intensity of the foreign operations, the legal restrictions in the host country and the country risk of the home country do exert a significant effect on the decision between cooperative arrangement and a wholly-owned subsidiary. Conversely, for a large number of variables, no significant relationship seems to exist based on the combined results. This is the case, for example, for factor specificity, the r&d-intensity, the subsidiary size, the assets of the MNC and the sales volume of the MNC.

• Transactions of the Korean hydrogen and new energy society
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• v.23 no.6
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• pp.612-618
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• 2012

In this paper, in order to prevent electric shock of high voltage system of HFCV after crash test, insulation performance measurement methods were studied. Under conditions of in-use, insulation performance tests can be divided into measurement method using the vehicle's own RESS as DC voltage source and measurement method using DC voltage from off-vehicle sources. However, these tests can not be applied after a post-crash because parts of high voltage system cover should be removed, and insulation performance can be influenced during these tests. Therefore, we proposed post-crash insulation performance test methods for preventing electric shock through problem analysis of previous post-crash insulation performance tests. Also, test equipment which can measure voltage absence and total energy was developed. We verified performance of the equipment through experiments with vehicle test.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.232-238
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• 2016

This paper presents protection techniques against electric shock in low voltage DC(direct current) grounding systems depending on the analysis of earth fault current paths. Firstly, the comparison between alternating current and direct current on human was conducted, and current threshold values for each current path and for long duration were analyzed. Secondly, the analyses of the earth fault current flows were performed depending on the grounding types and earth fault conditions. Lastly, based on these analyses, adequate protection measures of electric shock depending on low voltage DC grounding types were provided.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.1
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• pp.227-231
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• 2016

Electrical disasters have not been greatly reduced despite continuous prevention efforts until now. However, the smart distribution board which can be measured information about general electrical condition such as current, voltage, power, power factor etc. and electrical safety condition such as over-current, leakage current, arc etc. and communicated analysis information about electrical condition with server will be helpful for the prevention of electrical disasters through real-time surveillance and data analysis under smart grids based on the two-way communication. In this paper, the proposal standard of smart distribution board for electrical safety is suggested about the structure, functional requirements of compositions, communication, security and so on.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.64 no.1
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• pp.188-195
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• 2015

This paper presents measurement error reduction technique of touch and step voltage of grounding system based on numerical analysis. When measuring touch and step voltage of grounding system, auxiliary current probes should be located at suitable places. However, the auxiliary probes can not be located at suitable places in such cases as there are buildings and pavements. Therefore, in this paper, we provided measurement error reduction technique of touch and step voltage of grounding system according to the positions of auxiliary probes and angle between auxiliary probes. Also, measurement error analyses of touch and step voltage of grounding system have been conducted using more than one current probe. Based on these analyses, recommended positions of auxiliary probes within allowable measurement errors were presented.

• 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.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2019-2021
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• 2005

This paper describes the cut off time and the current characteristics of virgin RCDs and deteriorated ones in the seashore. The RCDs(Residual Current Protective Devices) are used for protecting the human body from electrical shock and for preventing facility accidents. According to the Korean standards, the RCDs are installed in panel boards. When RCDs are installed outside, they must be enclosed inside waterproof cases. In the case that RCOs are employed at temporary power sites and electrical facilities on the road, they are exposed to the external environment. As a result, the RCDs deteriorated in the seashore for 3 months showed high failure rate, while the virgin RCDs all complied with Korean Standard. Considering that the RCDs are used under exposed condition outside, the reliance of RCDs must be ensured by modifying the related regulations and codes and by developing Improved models advanced in their performance.

• Proceedings of the KIEE Conference
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• 2005.07c
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• pp.2046-2048
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• 2005

This paper deals with ground potential rise of structure grounding electrode when a test current flows through grounding electrode. In order to analyze the potential gradient of ground surface on structure grounding electrode, the reduced scale model has been used. The structures were designed through reducing real buildings and fabricated with four types on a scale of one-one hundred sixty. The supporter was made to put up with weight of structure and could move into vertical, horizontal, rotary direction. When a test current flowed through structure grounding electrodes, ground potential rise was the lowest value at electric cage type(type B). According to resistivity and absorption percentage in concrete attached to structure, the potential distribution of ground surface appeared differently.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.66 no.6
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• pp.995-1000
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• 2017

In this paper, we present an electrical arc detection algorithm using the mash-up analysis technique which is the core technology for the autonomous electrical safety management system(AESMS) of the multi-unit dwellings. The mash-up analysis technique analyzes the voltage, load current, zero phase current data simultaneously to judge arc faults. In order to develop the arc fault detection algorithm, the characteristics of series arc and parallel arc were analyzed. Also, we propose the mash-up analysis technique that analyzes waveforms of voltage, load current, and zero phase current at the same time. The arc fault detection algorithm was developed using the mash-up analysis technique. The developed algorithm can prevent electrical disasters in an effective way through accident prediction, and it will be used as a basic technology to introduce an autonomous electrical safety management system.