• Proceedings of the Korean Radioactive Waste Society Conference
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• 2012.10a
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• pp.255-256
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• 2012

• Development and Reproduction
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• v.21 no.4
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• pp.475-475
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• 2017

• Proceedings of the KIEE Conference
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• 2002.07b
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• pp.990-992
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• 2002

30kW electrical power conversion system is delveloped for the variable speed wind turbine system. In the wind energy conversion system(WECS) a synchronous generator with field current excitation converts the mechanical energy into electrical energy. As the voltage and frequency of generator output vary according to the wind speed, a dc/dc boosting chopper is utilized to maintain constant dc link voltage. Grid connection type PWM inverter supply currents into the utility line by regulating the dc link voltage. The active power is controlled by q-axis current which the reactive power can be controlled by d-axis current reference change. The phase angle of utility voltage is detected using s/w PLL(Phased Locked Loop) in d-q synchronous reference frame. This scheme gives a low cost power solution for variable speed WECS.

• Journal of the Korea Safety Management & Science
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• v.12 no.3
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• pp.81-91
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• 2010

This study carried out the investigation about the actual conditions of the management, disaster analysis and safety awareness on excavator in one of construction equipment and tried to make it's preventive measures. To achieve this, first of all, the accident of the internal Construction Industry process Investigation and Analysis, and then analyze an cause of accident based on it. Next, For the conditions of safety management conduct a survey to Investigation and Analysis and Propose preventive measures. The results of this study can be summarized as follows. 1st, Status of safety awareness and management of construction equipment tend to seek quickly and easily for the interests of sight. 2nd, Half the precincts of the equipment is causing major disaster. 3rd, The risk of excavator operation's indicators and drivers is so much potential. 4th, The preventive measures are needed for strengthening safety education, professional legal education, changes in safety awareness, the development of prevention system.

• 한국전자현미경학회:학술대회논문집
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• 2005.11a
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• pp.135-139
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• 2005

• Proceedings of the Korea Air Pollution Research Association Conference
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• 2004.05a
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• pp.194-196
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• 2004

• Proceedings of the Korean Environmental Sciences Society Conference
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• 2016.10a
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• pp.227-227
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• 2016

• Proceedings of the KIEE Conference
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• 1998.11a
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• pp.128-130
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• 1998

A simplified control method for the single-phase active power f1Iter is proposed. This method has the advantages of using only one current sensor, a simple control circuit and low implementation cost. A model of this method is derived. A prototype is also developed to demonstrate the performance of this method. The test results show that the proposed active power filter has the expected performance.

• Proceedings of the Materials Research Society of Korea Conference
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• 1998.08a
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• pp.115.4-115
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• 1998

• Proceedings of the KIEE Conference
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• 1994.07a
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• pp.369-372
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• 1994

In this paper, a voltage type dual PWM converter which achives the bidirectional power flow between a AC supply and a DC bus voltage is described. In PWM modulator, there exist a time difference between the sampling time and carrier wave, it achieves stable modulation even the disturbance in the synchronous AC source voltage. And this paper proposes the compensation method and the control method related a disturbance of synchronous signal using the low pass filter and phase shifter for the stable modulation. As a result the voltage type dual PWM converter makes the imput current wave as sinusoid, and performs the high power factor driving.