• Journal of Magnetics
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• v.18 no.3
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• pp.250-254
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• 2013

In this research, the linear electrical generator in wave energy farm utilizing resonance power buoy system is studied. The mechanical resonance characteristics of the buoy and the wave are analyzed to maximize the kinetic energy in a relatively small wave energy area where WRPS is operated. In this research, we chose an analog model of the linear electrical generator of which size is one-hundredth of an actual size of it in WPRS (Wave energy farm utilizing Resonance Power buoy System) prior to verifying the characteristics of actual model of linear electrical generator in WRPS. In addition, the finite element analysis is conducted using commercial electromagnetic analysis software named MAXWELL to examine the electric characteristic of linear generator. Finally, for the verification of dynamic and electric characteristics of linear generator, the prototype was manufactured and the experiments to measure the displacement and the output electric power were performed.

• Journal of Ocean Engineering and Technology
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• v.33 no.5
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• pp.447-453
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• 2019

Recently, environmental regulations have been strengthened for SOX, NOX, and CO2, which are ship exhaust gases. In addition, according to the 4th Industrial Revolution, research on autonomous ship technology has become active and interest in electric propulsion systems is increasing. This paper analyzes the power load characteristics of an electric propulsion ship, which is the basic technology for an autonomous ship, in terms of energy management. For the load analysis, data were collected for a 6,800 TEU container ship with a mechanical propulsion system, and the propulsion load was converted to an electric power load and clustered according to the characteristics using a SOM (Self-Organizing Map). As a result of the load analysis, it was confirmed that the load characteristics of the ship could be explained by the operation mode of the ship.

• Journal of the Semiconductor & Display Technology
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• v.20 no.3
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• pp.83-86
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• 2021

In this paper, electric fields in electromagnetic reverberation chambers, which are used as a substitute facility for EM-free anechoic chambers, are analyzed. This paper focused on the 4-5 GHz band, which is expected to adversely affect equipment. To analyze the field uniformity inside the electromagnetic reverberation chamber, electric field strengths are sampled and finite-difference time-domain method was used for numerical analysis. Moreover, Quadratic residue diffuser was used to improve the characteristics of the electromagnetic reverberation chamber and the uniformity of the internal field strength. Standard deviation, tolerance characteristics, and partiality characteristics were compared while varying the aiming point of transmission antenna.

• 한국연소학회:학술대회논문집
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• 2006.10a
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• pp.253-259
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• 2006

The effect of DC electric fields on the flame extinction was investigated experimentally in counterflow configurations for the methane/oxygen/nitrogen diffusion flame. The electric fields was applied by connecting the high voltage and ground terminals to the upper and lower burners, respectively. In case of having electric fields, several modes of flame extinction was observed according to the electric field intensity and strain rate defined by the exit velocity. To visualize and characterize the flame structure and intensity, planar LIF technique was adopted for OH radicals. Consequently, several length scales, including the flame width, thickness, and height from the burner tip, were introduced to explain the various flame behaviors and to characterize the flame extinctions. It was found that the variation of flame width and the chemical reaction are strongly related to a critical electric field intensity, thus the various modes of diffusion flame extinction could be observed due to the electric fields.

• Proceedings of the KIEE Conference
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• 2004.11c
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• pp.547-549
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• 2004

This system is monitors the degree of aging happened at the electric machine. It detects electromagnetic wave generated from the insulator when the voltage is applied to the machine. By analyzing the internal and external factors make the electric, mechanic, or thermal characteristics of the electric machinery deteriorate the electric insulation and eventually cause the partial electric discharge. The continuous partial electric charge accelerates the insulation aging and the insulation breakdown happens at last. This system consists of the relays connected with 10 sensors (40 total) detecting the partial electric discharge ans the temperature, the server, ans the program analyzing and storing the data.

• Proceedings of the KIPE Conference
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• 2002.07a
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• pp.593-597
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• 2002

The power conversion system for Fuel Cell Electric Vehicle(FCEV), technical trend, and a various type of Fuel Cell and its characteristics are presented. Especially, this paper is focused on the control methods of power conversion devices applied for the Fuel Cell Electric Vehicle, configuration of power system and operation mode of the bidirectional DC/DC converter. The prevalent topology for the power conversion systems, simulation results and development a tendency of FCEV and it's market investigations are introduced.

• Journal of the Korean Society of Safety
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• v.29 no.3
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• pp.28-33
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• 2014

Regarding the characteristics of fatal electric shock accident during the past 10 years, fatalities occurred more frequently in July & August, and AM 10-12 PM & 14-16. Also, the electric shock accident is occurred more frequently in the age group from 30 to 40. Especially, the fatal electric shock accident in construction industry covered more than half of total industry. Therefore, it is strongly requested for the protection technology of an electric shock from the low voltage electric path, grounding method and workers. The aim of this study is to propose the policy about the equipment performance standards and/or worker's safety standards to revise the standards for preventing electric shock accidents on safety workings.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.61 no.12
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• pp.1959-1963
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• 2012

Since electric railway load is variable largely due to starting and braking characteristics as well as various operation patterns, load modeling is not easy but complicated. For this reason, a simple technique for modeling of electric railway load of is required to analyze the AC substation system of electric railway. In this paper, a modeling technique of converter-based electric railway load is proposed and is tested using nonlinear loads on Matlab/Simulink.

• Journal of the Korean Society of Safety
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• v.32 no.2
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• pp.21-26
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• 2017

According to the data of Korea Occupational Safety and Health Agency, electric shock accidents during recent 11 years exceeded more than 60% in architecture/other and construction work, the countermeasures for safety are required in the harsh environment of a construction site where moving electric machines and equipments are widely used. The establishment of countermeasure for insulation degradation and defect is required, in consideration of increasing trend for accidents caused by defective insulation among low voltage electrical installation each year. The aim of this study is to propose the policy about portable electrical tool standards and/or worker's safety standards for preventing electric shock accidents on safety workings, and is to develop the technology and the safety device to prevent electric shock for accident prevention reduction through experiments. It obtained the followings through this study; statistical data analysis of late about 10 years of electric shock-related industrial accidents analysis and portable electric tools; safety device development of 'device for testing continuous grounding and power shut-down' to prevent electric shock from portable electric tools. Furthermore, developed results and proposal in this study will help to prevent the electric shock accidents from portable electric tools and will be expected the utilization of policy formulation, educational data and field supplement of the safety device, and etc.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 2008.11a
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• pp.679-680
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• 2008