• Proceedings of the KAIS Fall Conference
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• 2009.05a
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• pp.376-377
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• 2009

현재 철도는 물류의 운송과 대중교통수단으로 다양하게 활용되고 있다. 또한 친환경적인 면에서 매우 중요한 교통수단으로 각광을 받고 있다. 이에 따라 철도의 안전은 고려해야 할 가장 중요한 부분 중에 하나이다. 특히 철도의 건널목과 역사 내의 플랫폼과 같은 개방된 공간에 대한 안전관리는 매우 중요하다. 개방된 공간에서는 사고발생의 위험요소들이 다수 존재하기 때문에 이러한 위험요소들을 줄이기 위해 열차의 1차적인 통제를 담당하는 기관사와의 상황인식 정보의 공유가 필요하다. 상황인식 정보는 특정 공간에 따라 다양하게 존재할 수 있다. 따라서 OSGi 플랫폼을 사용하여 다양한 상황인식 정보들을 공유하고 활용할 수 있도록 하는 것이 본 연구의 목적이다.

• Proceedings of the KIEE Conference
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• 2001.11b
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• pp.142-145
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• 2001

Recently transmission and distribution power facilities have been often damaged severely by fire which broke out around the facilities in forest. It causes a power failure and thus gives an economic losses to both the public and the power utilities. Sometimes the fire can happen by an electrical accident such as the electrical short circuit or the ground short circuit. In this paper, trend of breaking out the fire has been investigated and an countermeasure against the economic losses due to the fire has been studied.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.06a
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• pp.256-257
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• 2008

Recently, with the increase of demand of electricity, electric cable or electric transfer machine are rapidly developed and meet the demand with the extra high voltage and massive capacity, the dangers of electrical accident of insulator are increasing by the electric stress, insulation degradation and insulation breakdown in insulator. In this paper, it is investigated that the temperature dependance of dielectric strength in nano-composites. We obtained that breakdown voltage of 0.4 [wt%] specimens is higher than the other $SiO_2$ content.

• Journal of the Korean Society of Safety
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• v.25 no.2
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• pp.24-28
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• 2010

The nuclear power Plant onsite AC electrical power sources are required to supply power to the engineering safety facility buses if the offsite power source is lost. Typically, Diesel Generators are used as the onsite power source. The 125 VAC buses are part of the onsite Class 1E AC and DC electrical power distribution system. The DC power distribution system ensure the availability of DC electrical power for system required to shutdown the reactor and maintain it in a safety condition after an anticipated operational occurrence or a postulated Design Base Accident. Recently, onsite DC power supply system trip occurs the loss of system function. To obtain the performance such as reliability and availability, we analyzed the cause of battery charger trip and described the improvement of DC power supply system reliability. Finally, we provide reliability performance criteria of charger in order to ensure the probabilistic goals for the safety of the nuclear power plants.

• The Transactions of the Korean Institute of Power Electronics
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• v.19 no.3
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• pp.257-265
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• 2014

This paper proposes a simple compensation method for switches of the unclamped voltage in the three-level NPC inverter. Voltages of inner-switches can be unclamped in the three-level NPC (neutral point clamped) inverter. It can cause the problem of the switch fault accident. By adding a capacitor, switches of the unclamped voltage can be clamped. Through the analysis of the circuit, the reason behind switches being unclamped was verified which leads to the solution method that designs a compensation capacitor. The proposed method was validated through the simulation and experimental results.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.67 no.6
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• pp.708-714
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• 2018

Islanded operation of a microgrid can ensure the reliable operation of the system when a large accident occurs in the main grid. However, because the generation capability of a microgrid is typically limited, a microgrid operator should take islanded operation risk into account in scheduling its generation resources. To address this problem, in this paper we have proposed two unit commitment formulations based on the islanding scenario that reflect the expected and worst-case values of the islanded operation risk. An optimal resource scheduling strategy is obtained for the microgrid operator by solving these optimization problem, and the effectiveness of the proposed method is investigated by numerical simulations.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.1169-1170
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• 2007

The primary objective of this paper is to examine the capacity of electrical transmission in electric railway according to the type of feeding system. Although supply capacity of railway substation are sufficient and there is no accident, due to the electrical transmission limit of feeding line the voltage breakdown may occur when large capacity of electric load at feeding line exist. So, using multi-port analysis model, we draw P-V curve due to feeding method, load, location and power factor of electric locomotive.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2002.08a
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• pp.37-40
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• 2002

Ground connection began by experimenting lightning with the use of a kite and it means electric appliances, communication equipments, measuring instruments and so on connecting the Earth in order to flow away overcharged electricity. There are two kinds of earth connection: Power Ground and Signal Ground. Power Ground is for preventing an electric shock and in general there's no current in the connector. However in an accident, there's a quick flow of electricity out to the Earth. Signal Ground is not only for the safety of appliances but also for the safety of equipment operation. This paper is about connection for noise and interference reduce in order to prevent wrong operation and distortion of signal in the electrical appliances which can take place in cable TV.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.11
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• pp.1009-1014
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• 2007

A detailed study on aged sleeves for old transmission lines was carried out to clarify the deterioration of sleeves and the condition of installation. A lot of removed aged sleeves from transmission lines were investigated. Many biased installed cases and corrosion of steel sleeve part were found. These defects can cause a serious accident such as blackout during operating. The temperature distribution within sleeve of ACSR conductor was precisely measured and examined, conducted as part of series of studies on large currents in transmission lines. According to measurements of the conductor temperature near a joint(sleeve and clamp), the electrical resistance of joint is lower than that of the same length conductor. The detailed results were presented in the text.

• Annual Conference of KIPS
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• 2014.04a
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• pp.792-795
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• 2014

매년 고속도로 교통사고로 많은 사람이 목숨을 잃고 있으며 이 중 1차 사고에 이은 2차 충돌사고로 인한 교통사고는 전체 고속도로 교통사고의 14%이며, 치사율은 50%에 이른다. 본 논문에서는 고속도상의 2차 충돌사고 예방을 위한 실시간 사고 정보 분석 및 알림 기술을 제안한다. 제안 기술은 블랙박스와 내비게이션 길 안내 기술, 교통정보 및 센서를 활용한 사고 인식 기술, 통신형 내비게이션 및 위치 공유 기술 그리고 사고 정보 알림 기술을 바탕으로 현재 주행 중인 고속도로의 정보를 종합적으로 인식하여 사고 및 정차를 판별하여 사용자에게 알려줌으로써 2차 충돌사고를 예방한다.