• Proceedings of the KIEE Conference
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• 2006.07a
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• pp.282-283
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• 2006

A frequency relaying algorithm which is used system separation and load shedding to improve transient stability is proposed. The algorithm can trip the generator and shed load in the abnormal frequency condition. The computer simulations of load flow analysis is used to determine the amount of load to be shed in an under frequency condition. Furthermore dynamic brake energization in the simulation is performed for the control of overfrequency.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.96-98
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• 2002

A 765kV Transmission line system plays an important role in delivering the electric power produced at mid-western in Korea. This system will be constructed and operated normally on 2002. By doing the number of test operation in a given time, the reliability on the operation of 765kV transmission system could be secured.

• Proceedings of the KIEE Conference
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• 1998.07d
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• pp.1436-1437
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• 1998

In this paper, the result of experimental investigation into the streaming electrification phenomena of insulating oil under an external dc field effect is described. Energization by positive dc voltage enhanced the streaming electrification. but when the applied voltage was negative, the polarity of streaming current was field strength dependent.

• 제어로봇시스템학회:학술대회논문집
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• 2001.10a
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• pp.157.2-157
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• 2001

This paper describes the synergism of Artificial Neural Network and Fuzzy Logic based approach to improve the reliability of transformer differential protection, the conventional transformer differential protection commonly used a harmonic restraint principle to prevent a tripping from inrush current during initial transformer´s energization but such a principle can not performs the best optimization on tripping time. Furthermore, in some cases there may be false operation such as during CT saturation, high DC offset or harmonic containing in the line. Therefore an artificial neural network and fuzzy logic has been proposed to improve reliability of the transformer protection relay. By using EMTP-ATP the power transformer is modeled, all currents flowing ...

• Proceedings of the KIEE Conference
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• 2002.11b
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• pp.227-230
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• 2002

A 765kV Transmission line system plays an important role in delivering the electric power produced at mid-western in Korea. This system will be constructed and operated normally on 2002. By doing the number of test operation in a given time, the reliability on the operation of 765kV transmission system could be secured.

• Proceedings of the KIEE Conference
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• 2007.07a
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• pp.608-609
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• 2007

본 논문에서는 765kV 선로의 편단가압 시 기존 운전중인 선로에서의 전압상승에 대하여 분석하였다. EMTP-RV를 이용하여 당진T/P$\sim$신서산S/S$\sim$신안성S/S의 실계통 모델을 구현하여, 선로길이 및 전원용량을 변경시키면서 시뮬레이션 하였으며 그 결과를 분석하였다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.6
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• pp.932-937
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• 2008

The transformer inrush current can cause a voltage drop by source impedance. This current can impact sensitive loads by the voltage drop. Therefore, it is necessary to take measures to limit this inrush current. This study, described in this paper, analyzes the power quality affected by transformer inrush current using the X power system in Korea. The Electromagnetic Transients Program(EMTP) is used to analyze the transient phenomenon. We discuss a method to model the hysteresis curve of the transformer in EMTP. We carried out various simulations to analyze the power quality during transformer energization. The analysis results of voltage drop by the inrush current occurrence when certain requirements are met are presented.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.177-185
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• 2000

In this study, the characteristics of various electricity and high resistivity ash collection were measured at superimposed nanosecond pulse energization. The pulse was generated through the hydrogen thyratron. Superimposed pulse was nanosecond duration pulse that had fast pulse rising time 100[ns], short pulse width 500∼850[ns] and pulse fall time 400∼750[ns]. The results of this study are summarized as followings; Frist, compared with the DC ESP(electrostatic precipitator), superimposed pulse ESP could induce higher peak voltage, and had the about 30[%] reduction of ESP collection area and 50∼80[%] reduction of power consumption. showing the same efficiency. Second, enhancement factor H had 1.9∼3.6 with the increase of migration velocity.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.477-479
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• 2000

This paper presents an analysis which compares the effectiveness of different temporary safety grounding methods on working overhead distribution system. The analysis studied direct energization at fault conditions with seven scenarios. The results show that the scenario, single point safety grounding on the working pole with brackets Pairs spaced 2 km apart on both side of a work site is safest grounding method. This can be used to evaluate lineman safety on a overhead distribution systems in Korea.

• Journal of Korean Academy of Nursing Administration
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• v.22 no.1
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• pp.57-66
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• 2016

Purpose: This exploratory study was done to categorize medical personnel's perceptions of burnout and analyzed the characteristics. Methods: Q methodology was applied using a 45 Q-sample categorized on an 11-point scale which was completed by nurses and doctors working at a university hospital in Seoul, Korea. Collected data were analyzed using the PC-QUANL program. Results: Medical personnel's perceptions of burnout were categorized into three types; 33.83% of the total variance was explained. The first type was 'functionally deteriorating pressure' the second type was 'daily powerlessness' and the third was 'achievement-oriented re-energization'. Conclusion: There is a need to establish and apply intervention strategies for each type to alleviate medical personnel burnout and increase work efficiency to qualitatively improve medical services.