• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.205-210
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• 2014

The micro grid considered in this paper consists of a diesel generator, a photovoltaic array, a wind turbine, a fuel cell, and a energy storage system. This paper explains and simulates the micro grid components in terms of accuracy and efficiency of having a system model based on the costs of fuel as well as operation and maintenance. For operational efficiency, the objective function in a diesel generator consists of the fuel cost function similar to the cost functions used for the conventional fossil-fuel generating plants. The wind turbine generator is modeled by the characteristics of variable output. The optimization is aimed at minimizing the cost function of the system while constraining it to meet the customer demand and safety of micro grid. The operating cost in fuel-cell system includes the fuel costs and the efficiency for fuel to generate electric power. To develop the overall system model gives a possibility to minimize of the total cost of micro grid. The application of optimal operation can save the interruption costs as well as the operating costs, and improve reliability index in micro grid.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.18 no.2
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• pp.157-166
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• 2004

Recently, switchboards for MV/LV distribution customers have been united and digitalized rapidly. This paper suggestes the effective information visualization method for the data mesured from cubicle switchboard for MV/LV distribution customers. We developed the algorithm that analyzes a large number of mesured data and displays them to users overall, such as fire index, power condition index, switchboard safety index, and power diminution index. Using a touch screen made users to operate it easily. User interface was also strengthened by taking graph visualization. We guess the information visualiztion method suggested in this paper shows the new direction that heavy electrical equipments including switchboards are going to develop in the future.

• Journal of Korean Tunnelling and Underground Space Association
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• v.13 no.5
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• pp.371-383
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• 2011

It is important to secure illumination for the driver's safety because the tunnel is a space for changing brightness quickly, and lighting fixtures of the tunnel have consumed a lot of electric lighting energy for operating in both the daytime and at night. This study aims to evaluate daylighting performance of Mirror Reflector System for luminous environment improvement of tunnel space by using RADIANCE simulation program. The results of simulation show that illuminance of bar type is higher than illuminance of pole type at 20 m from the tunnel entrance.

• Journal of the Korean Society of Systems Engineering
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• v.10 no.1
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• pp.43-48
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• 2014

The door system for railway vehicles is the critical device directly influences on safety and satisfaction of passengers, Recently, electrical type of passenger door system is widely used for EMU type train instead of pneumatic type of passenger door system. The estimation of MTBF and failure rates for electrical type door system is essential. The manufacturor simply provides intrinsic reliability data for the railway operator. But actual reliability data based on operation and maintenance data is not complying with intrinsic reliability. In this study, operation and failure data associated with electrical door system were analyzed in order to determine actual MTBF and failure data. Intrinsic reliability data and service reliability data were studied to finallize much more practical and reliable actual reliability. Relax 2011 was used to predict intrinsic reliability and 217Plus model was also used to estimate of actual reliability data based on field data. Furthermore, it is necessary to keep studying on reliability prediction methodology and applying it in the field and doing research on improvement of reliability through feedback as well.

• Journal of Distribution Science
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• v.18 no.9
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• pp.67-75
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• 2020

Purpose: The purpose of this study is to enhance sales promotion efficiency for using solid refuse fuel facilities. Renewable energy technology using Solid Refuse Fuel (SRF) is an economic efficiency technology that recovers waste by burning various wastes. A survey on the pollutants discharged from the solid fuels facilities was investigated so that the SRF facilities could be expanded, distributed and reflected in the policy. Research design, data, and methodology: In this study, 9 business sites using SRF and Bio-SRF as main raw materials were investigated for 2 years. The characteristics of target business sites such as the type of fuel used, combustion method, combustion temperature, daily fuel consumption and environmental prevention facilities were studied. Results: The average pollution & ammonia concentration of Bio-SRF facilities was found to be 88.15% higher than that of SRF facilities. But the average acetaldehyde concentration of SRF facilities was found to be 88.15% higher than that of Bio-SRF facilities. Conclusions: The main issue is how much electric power generation using combustible materials affects air pollution. The waste recycling law provides the standard value according to the fuel property, but there is a considerable gap with the mixed fuel. Therefore, for efficient utilization of facilities using solid fuel products, additional research is needed to improve the distribution structure of exhaust pollutants is needed.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.9 no.7
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• pp.1439-1444
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• 2005

AIS needs hish efficiency and safety in terms of operational management and, in the aspect of service range, it is time to minimize shadow regions through propagation evaluation of AIS transmitter. Thus this study analyzes shadow regions and the scope of propagation of waves from stations through the electric wave environment of AIS. First, this study examines the characteristics of AIS wave and draws up methods to analyze the scope of propagation of waves according to the characteristics. Second, this study finds out service regions and shadow regions of the 22 stations across the nation by analyzing the actual data based on climate and topography. Lastly, this study summarizes the results of wave conductivity evaluation and conductivity problems and proposes improvement measures.

• Journal of the Korean Society of Hazard Mitigation
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• v.8 no.4
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• pp.87-90
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• 2008

This research is to study and analyze our country's management of disasters, the present condition of cultural heritages bases on the examples of temples, and Japan's safety management prevention of buddhist temple. As a result, this research aims to how to improve the temple fire prevention system. To improve the anti-fire system of temples, it is important to make new laws about fire lose to minimize cultural property lose. Secondly, to protect self-contained type fire alarm device, with aerosol type hand propelled fire extinguishers to prevent fire lose. Lastly, construction work of electric engineer is necessary to prevent temple fire loses.

• The Transactions of the Korean Institute of Electrical Engineers A
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• v.55 no.8
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• pp.322-328
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• 2006

In this paper, The impulse un-tripping characteristics and the electro magnetic compatibility characteristics are compared with each other. The performance of impulse un-tripping test exists at domestic standard (KSC 4613). However test items are insufficient because the more test items such as EMC exist at international standard (IEC). Also, Electric Appliances Safety Certificate has taken the certificate test since July 2004 in Korea but did not confirm the EMC performance for RCCBs made in Korea. Thus, in this paper, We experiment with Oscillatory waves immunity test and the 7 EMC tests for 32 RCCBs of 4 types (mini, home standard, plug, outlet) for 16 brands according to IEC standard 61009-1 and 61008-1. As a result, 24 RCCBs proved to be poor for surge immunity test. However the RCCBs operating incorrectly for surge immunity test operate correctly for oscillatory waves immunity test. Thus, the correlation between oscillatory waves immunity test and EMC test is little and standard for compatibility of combination surge at IEC 61000-4-5 should be added to KS standard as soon as possible.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.1
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• pp.19-23
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• 2000

Partial discharges(PD)in air insulated electric power apparatus often lead to deterioration of solid insulation by electron bombardments and electrochemical reaction. The PD caused to reduce the life time of power apparatus and to increase power losses. Thus understanding and classification of PD patterns in air are very important to discern sources of PD. In this paper, PD in air by using statistical methods was investigated. We classified air discharges, corona, surface discharges and cavity discharges by Kohonen network. For classification of PD patterns, we used statistical operators and parameters such as skewness$(S^+,\; S^-),\; kurtosis(K^+, K^-),\; mean phase(AP^+, AP^-)$, cross-correlation factor(CC) and asymmetry derived from the mean pulse-height phase distribution$(H_{avg}(\phi))$, the max pulse-height phase distribution $(H_{qmax}(\phi))$, the pulse count phase distribution $(H_n(\phi))$ and the pulse height vs. Repetition rate $(H_q(n))$.

• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.431-433
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• 2000

The hydroelectric Power plant of the KOWACO have been establishing and operating a full scale electric power facility, doing the largest generation during the flood period of the summer season. When the huge capacity generator is run like the Chung-Ju's hydroelectric Power plant, the generator current per generator flows a great current estimated at 5,900 A. The bus bar of a great current flows in cubicle, owing to the bus bar current Eddy current is created around magnetic substance and a local heating phenomenon occurs due to Joule heat finally. a local heating phenomenon still exists the danger of safety accident due to contact and accompanies losses enough to healing capacity inevitably. this study applies and examines related theory and numerical formula about the heating cause of a great current & enforces technical verification about the method of heating reduction previous managed at the site.