• Journal of Energy Engineering
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• v.12 no.3
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• pp.241-252
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• 2003

As more and more residential complexes will be developed in the future, this paper tries to establish the definitions and standards for the estimation of power demands in these areas and propose standards for the estimation of power demands for power companies and construction companies to settle the debates surrounding this issue. Through a survey and analysis of existing areas, new standards that will enable more accurate estimation of power demands in new cities complexes to be developed in the future are established by calculating the average load density, load factor, utilization factor by area, use and building size after dividing the facilities into building type. Also, for general hospitals, sports facilities and government buildings of the non residential building category, metropolitan areas, where these facilities are concentrated, are surveyed and analyzed.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.16 no.2
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• pp.90-97
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• 2002

In this paper we study the performance test items and improvement plans of surge protective devices for low-voltage power circuits used in railway system. Above of all, the sources of electromagnetic interference in railway system are researched. And then we compared domestic railway standard with IEC and IEEE standards far the test items and methodologies of surge protective devices. Through the investigations, we found that the domestic standard is behind in the number of test items and methods on surge protective devices. As the countermeasures, we suggest removing component tests of surge protective devices, separating standards for power and signal standards, and using international surge waveform. In applying to domestic railway surge protective devices, surge limiting voltage measuring and surge endurance tests by international standard methods are good result.

• Korean Journal of Optics and Photonics
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• v.34 no.3
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• pp.99-105
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• 2023

The performance of astronomical telescopes can be negatively affected by atmospheric turbulence. To address this issue, techniques for atmospheric turbulence correction have been developed, requiring the simulation of atmospheric turbulence in the laboratory. The most practical way to simulate atmospheric turbulence is to use a phase plate. When measuring a phase plate that simulates strong turbulence, a Shack-Hartmann wave-front sensor is commonly used. However, the laser power decreases as it passes through the phase plate, potentially leading to a weak laser signal at the sensor. This paper investigates the need to control the laser power when measuring a phase plate that simulates strong atmospheric turbulence, and examines the effects of the laser power on the measured wavefront. For phase plates with relatively high Fried parameter r₀, the laser power causes a variation of over 10% in r₀. For phase plates with relatively low r₀, the laser power causes a variation of less than 5%, which means that the influence of the laser power is negligible for phase plates that simulate strong atmospheric turbulence. Based on the system described in this paper, a phase plate simulating strong atmospheric turbulence can be measured at a laser power of 5 mW or higher. Therefore, controlling the laser's output power is necessary when measuring a phase plate for simulating atmospheric turbulence, especially for phase plates with low r₀ values.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2008.05a
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• pp.78-81
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• 2008

Capacitors are known as condensers. They play an important in the industrial site because of benefits such as var support, improved voltage control and power factor, increased system capacity, and reduction of system power losses. But capacitors can be seriously affected by bad power quality such as transient and impulsive overvoltage, overload, harmonics. Capacitor standards and application guides are revised or supplemented by speedy technology advancements in the manufacturing of capacitors and in the power electronics. This paper presents various illustrations and comparison for several standards of power system capacitors.

• Proceedings of the KIEE Conference
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• 2004.05b
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• pp.220-222
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• 2004

The IEC standards related to the Technical Regulation in Korea Electricity Business Act are classified into the standards/guides for electrical system and the specifications for electrical equipment/materials. IEC Standard 60364 "Electrical Installations of Buildings" and IEC Standard 61936 "Power Installations Exceeding 1 kV AC" prepared by IEC Technical Committee(TC) 64 and TC 99 respectively, are representative standards for electrical installations of buildings, substations, industrial plants, etc.

• Proceedings of the KSR Conference
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• 2008.06a
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• pp.1549-1552
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• 2008

Urban transit consists of signaling system, railway systems, power facilities systems and the other complicated facilities and the standards notify the standardizations, safety standards, performance standards and quality certification standards according to the Urban Transit Act. The government notifies and recommends these standards to improve the performance, safety and maintenance efficiency of urban transit. Now, we need to manage the records and traceability of the standards because they have reciprocal relations with the others so that, if some standards have been changed it could make some problems to the others. As a result, in this research, we suggest the way to manage the traceability of the standards by using the computation support tools.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.2065-2069
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• 2008

Urban transit consists of signaling system, railway systems, power facilities systems and the other complicated facilities and the standards notify the standardizations, safety standards, performance standards and quality certification standards according to the Urban Transit Act. The government notifies and recommends these standards to improve the performance, safety and maintenance efficiency of urban transit. Now, we need to manage the records and traceability of the standards because they have reciprocal relations with the others so that, if some standards have been changed it could make some problems to the others. As a result, in this research, we suggest the way to manage the traceability of the standards by using the computation support tools.

• Proceedings of the Korean Nuclear Society Conference
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• 2005.05a
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• pp.976-977
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• 2005

• Journal of Drive and Control
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• v.7 no.3
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• pp.13-19
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• 2010

• The Transactions of the Korean Institute of Power Electronics
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• v.9 no.4
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• pp.390-396
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• 2004

Recently, there have been Increasing demands for high power factor and low harmonic distortion in the current drawn from utility. The harmonic limits imposed by international standards. It need the PFC techniques in order to reduce line current harmonics and comply with the standards. The average current control method that is the most proper PFC control method in a switching power supply of middle and high power has been used mostly to PFC control method. However, the switching device of PFC circuit has frequently destructed at power return after instantaneous power interrupt. Therefore, this paper have verified the cause of this problems and proposed the solution through simulation and experiment