• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.161-163
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• 1998

The interruption performance of EHV class gas circuit breakers critically depends on the flow conditions inside interrupter and the external circuit conditions. In case of puffer type gas circuit breakers the flow conditons are significantly influenced by arcing time. In this paper the calculated results of RRRV and pressure rise at current zero with varying arcing time are presented and the effect of arcing time on the thermal interruption performance of EHV class gas circuit breakers is analyzed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.21 no.8
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• pp.81-86
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• 2007

This paper proposes the scheme to improve the current direct load control(DLC) program by inspecting the problems of the DLC program. In order to increase the number of the customers participating DLC program, a reduction of the base incentive and an increase of the direct load control incentive are suggested based on the interruption cost of electric power considering the characteristics of load types and the introduction of demand side bidding is recommended. Secondly, the standards of power system operations is required to control DLC program efficiently for the penalty, interruption times, the number of interrupting loads, notice time for the load interruption and the periods of the DLC program contract.

• KIEE International Transactions on Power Engineering
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• v.4A no.4
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• pp.171-177
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• 2004

In the current age of the information oriented society in which we live, many people use PCs and are dependant on the databases provided by the network server. However, online data can be missed during the occurrence of a blackout and furthermore, power failure can greatly effect Power Quality. This has resulted in the trend of using interruption-free live-line work when trouble occurs in a power system. However, 83% of the population receives an electric shock experience when a laborer is performing interruption-free live-line work. In the interruption-free method, education and training problems have been pinpointed. However, there are few instructors to implement the necessary training. Furthermore, the trainees undergo only a short training period of just 4 weeks. In this paper, to develop a method with no restrictions on time and place and to ensure a reduction in the misuse of materials, immersion type virtual reality (or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by performing the equivalent action in a safe environment. Thus, it can be valuable to apply this training system to such dangerous work as 'Interruption-free live-line work exchanging COS (Cut-Out-Switch)'. In this program, the user carries out work according to instructions displayed through the window and speaker and cannot perform other tasks until each part of the task is completed in the proper sequence. The workers using this system can utilize their hands and viewpoint movement since they are in a real environment but the trainee cannot use all parts and senses of a real body with the current VR technology. Despite these weak points, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has high potentiality.

• Proceedings of the KIEE Conference
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• 1998.07a
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• pp.164-166
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• 1998

This paper presents the results of the measured pressure-rise and the analyzed results of the cold gas flow-field in a 72.5kV 20kA gas circuit breaker for the electrical railway system. The analysis of cold gas flow field and the calculation of electric field strength have been performed in 3 types of interrupters and the low current interruption capability has been estimated for each of the gas circuit breaker considering the opening speed, the nozzle shape and the stroke length.

• Proceedings of the Korea Institute of Applied Superconductivity and Cryogenics Conference
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• 2003.10a
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• pp.291-293
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• 2003

Applicability and economical feasibility of a Superconducting Fault Current Limiter (SFCL) have been investigated using the PSS/E simulation for a bus bar coupling at the real 154 ㎸ KEPCO power grid near Seoul. For the investigated substation, the maximum fault current exceeds the interruption rating of 4 circuit breakers (CB) out of 9 installed in the substation. The simulation showed that a SFCL installed in the bus tie position effectively limits the fault currents to save 4 CBs, which are to be replaced by ones of gloater interruption rating, otherwise. We suggest that the optimum resistance of the SFCL be 10 Ohm for the given grid.

• Transactions of the Korean Society of Mechanical Engineers B
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• v.37 no.4
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• pp.353-358
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• 2013

The current interruption method is considered to be an efficient way of measuring the resistance of a fuel cell. In this study, the ohmic area specific resistances (ASRs) of polymer electrolyte fuel cells with different types of bipolar plates were evaluated using the current interruption method. The ohmic ASRs of both a fuel cell with graphite bipolar plates and a fuel cell with graphite foil-based assembled bipolar plates decreased as the current density increased. On the other hand, with increasing cell temperature, the ohmic ASRs of a fuel cell with graphite bipolar plates were decreased by a reduction in the proton transport resistance through the membrane, and the ohmic ASRs of a fuel cell with graphite foil-based assembled bipolar plates were increased by the differences in thermal expansion between different components of the bipolar plates.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.12
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• pp.74-81
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• 2011

A computational approach was developed to understand about the arc quenching process in a gas circuit breaker(GCB). This approach is a program to analyze the gas flow in the breaker. The arc is processed at the same time. The program was used the so-called FLIC method for gas analysis techniques. It was referenced that the arc is interpreted the 'a Simplified Enthalpy Flow Arc Model'. In order to validate about the results of the program, a Auto Puffer GCB was chosen as the test subject. Because, the breaker is the one that arc current is interrupted by using the arc heating. And also, the current interrupting capability can be obtained only owing to the positive utilization(auto puffer) of the clogging phenomenon, without other puffer actions. In this paper, it has been realized that the entire arc quenching process is computerized, which is based on the self-flow current interruption by the auto puffer action. This program, which was verified through experiments, produced good results.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.53 no.1
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• pp.22-30
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• 2004

As an information-oriented society comes, many people use PC and depend on database that network server has. However, the online data can be missed when a blackout happens and also a power failure effects on standard of judgment on Power Quality. Thus, it is reason of a trend using interruption-free live-line work when a trouble happens to power system. However, the 83％ among the number of people who receive an electric shock experience when a laborer is doing interruption-free live-line works. In interruption-free method, the education and the training problem has been issued. However, we have a few instructors for that training. Furthermore, the trainees have short training period, just 4 weeks. In this paper, to develope the method that has no restriction of a time and place and reduce the wasteful materials, immersion type virtual reality(or environment) technology is used. The users of a 3D immersion type VR training system can interact with the system by doing same action in the real safe environment. Thus, it can be valuable to apply this training system to a dangerous work like as "Interruption-free live-line work exchanging COS(Cut-Out-Switch)". In this program, the user works with a instruction on the window and speaker and can't work other tasks until each part of the task completed. The workers using this system can use their hands and viewpoint movement as he is in a real environment but the trainee can't use all parts and senses of a real body with the current VR technology. Despite of this weak point, when we consider the trends of improvement in electrical devices and communication technology, we can say that 3D graphic VR application has a high potentiality.

• Korean Journal of Occupational Health Nursing
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• v.30 no.2
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• pp.57-67
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• 2021

Purpose: This study was conducted to investigate the influence of professional self-concept, ego-resilience, and job stress on job performance in reemployed nurses after career interruption. Methods: The participants were 207 nurses who worked at hospitals with more than 100 beds located in Seoul, Gyeonggi and Gangwon provinces. The nurses had experienced a career interruption of at least one year, and had less than five years of experience at the current workplace. The collected data were analyzed utilizing SPSS 24.0 program and using descriptive statistics, t-test, ANOVA, Pearson correlation coefficients, and multiple regression. Results: The participants' job performance, professional self-concepts, ego-resilience, and job stress showed significant positive correlations. It was found that the professional self-concept, ego-resilience, and job stress had an effect on the participant's job performance in order, and explained 51.3% of variance in job performance. Conclusion: To improve the job performance of career disconnected nurses, it is necessary to reinforce job stress control, professional self-concept, and level of ego-resilience.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.6
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• pp.255-260
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• 2006

Arc Fault Current is an which occurrs in two opposite electrode. In this paper, arc current control algorithm is designed for the interruption of arc fault current which is occurred in the low voltage network. This arc is one of the main causes of electric fire. General arc current sensor has troubles for detecting arc currents, thus we would like to propose the arc current detection method without current sensor. In this parer, arc discharge currents within power lines are being detected through the arc current control algorithm.