• Journal of Korean Society of Transportation
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• v.11 no.3
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• pp.67-82
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• 1993

The effects of passing lanes on traffic flow on rural two-lane highways have been investigated in this research. Field study results were compared with the computer simulation model, TRARR, TRARR model appears to be in good agreement with field study results except that average speed and distribution of platoon sizes showed a small amount of discrepancy, which is believed to be caused by too large a headway definition of 6 second for a vehicle platoon. Using the TRARR model, 4 situations including the existing condition, installation of passing lanes, improvement of design speed, and expansion to a four lane highway were evaluated. Traffic volume levels of 500,1000, and 1500 vph and truck composition of 20 and 40% were also considered making a total of 24 computer runs. It is concluded in this research that the installation of passing lanes is the most effective method to improve traffic operation on two-lane high ways except the alternative of four lane highway expansion.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.17 no.9
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• pp.797-804
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• 2007

A study was carried out to investigate the fluid-structure interaction phenomena of buried hydrophone system that exposed complex loads due to handling, transportation and installation. The buried hydrophone system has necessarily neighborhood structures for installation. Because of the neighborhood structure, acoustic field is deformed. We analyze the piezoelectric-structural-acoustic coupled problem and the results to use a finite element analysis software, ANSYS, which has an coupled field analysis capability. The effect of the component of hydrophone system is revealed altogether in pressure distribution. So, we classify and analyze the problem by four different compositions for decomposition.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.13 no.2
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• pp.178-178
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• 1999

In recent years, the electromagnetic environments are varied with the increase of power consumption and the spread of household electric appliances. Most of the interests to date have concentrated in the area of human health effects associated with exposure to power frequency electric and magnetic fields, and thus the precise measurement and analysis are required. In this paper, the measurements and analysis of the extremely low frequency(ELF) electric and magnetic fields produced by actual 22.9[kV] distribution lines were performed. The experiments have been carried out by lateral profile, and the theoretical analyses were made by use of FIELDS program for the sate of comparison with the experimental data. Electric and magnetic field intensity were strong under power distribution lines, and were inversely proportional to lateral distance. The profiles of electric and magnetic fields were M and ∩ shapes, respectively, and the measured data were good in agreement with the theoretical results. Both the electric and magnetic field intensity were increased with increasing the measurement height.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.25 no.6
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• pp.42-48
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• 2011

Generally, the structure without the stator core Axial Field Permanent Magnet (AFPM) generator was simple and there was nearly no cogging toque. And because it had the wide driving rate area, it had been being mainly used in the small wind power generation system. However, AFPM generator with non-slotted stator can't generate high voltage at low wind speed due to long air-gap. It is the reason of output efficiency drop. Therefore, in this paper, the AFPM synchronous generator with internal rotor and dual slotted stators for the small wind turbine is studied, and deal with a cogging torque minimization through the determination of optimum pole-arc ratio.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.24 no.9
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• pp.150-158
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• 2010

We had experienced the several system failures which were concerned about zero sequence voltages at the tertiary side of 345[kV] transformers. In this paper, we had considered the zero sequence voltage and its reduction methods at the 345[kV] auto-transformer tertiary. For analysis, we used EMTP(Electro-Magnetic Transients Program). The calculation results by EMTP were compared with the measured data of the field tests. From the calculation and the field tests, we had verified that it is due to pre-saturation characteristics of the potential transformer. So, we had improved its saturation characteristics and applied it at real site. After improvements, we could reduce the zero sequence voltage below the setting level of the relay.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.29 no.12
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• pp.33-39
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• 2015

This paper examines the insulation performance of synthetic air and dry air. This examination was conducted based on dielectric strength in uniform and non-uniform field, electric field distribution by interior structure and defects in gas insulation switchgear (GIS) and insulation performance in different temperatures. From this review, it was found that eco-insulation gas required to possess low moisture content for power equipment in the distribution class. The results of this paper are valuable to ensure the insulation design and insulation reliability of GIS using air.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.295-297
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• 2004

The overvoltage generated by the lightning strokes has been doing considerable damage to the distribution network as well as the consumer facility until now. Because most of the lightning strokes are accompanied by a storm, the aftermath of damage to the consumer is so serious. Therefore it is very important to survey the optimal operation plan by the field test of distribution lightning facilities. In this paper we have accomplished the field test to verify the impulse characteristic of Secondary Arrester(SA), and analyzed the effect of the SA in power distribution system.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2004.05a
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• pp.335-340
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• 2004

To analyze risk factors of temporary power installations, the investigation was carried out for power receiving system and pack and panel boards at construction sites. The subject was variable such as an airport, an apartment, a municipal playground. There are many risk factors caused by inadequate working environments and the deterioration of temporary power installations using equipment with minimum safety devices at construction sites. There, it is intended to present problems and preventive measures against electrical shock accidents, through analyzing risk factors of real field condition and investigating temporary power installations all over the country.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.26 no.5
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• pp.48-57
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• 2012

This paper analyzes the characteristic of gird connected photovoltaic power generation system which is available to connect the utility. Renewable energy photovoltaic power system has been linked to the system to analyze the impact of photovoltaic system. It is measured that power data for the Grid connected photovoltaic power plant with instantaneous measuring and 3-sec measuring for 7 days. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. A cumulative probability approach is the most commonly used method to solve time varying harmonics. So, it is used 50[%] cumulative probability approach. This paper provides an in depth analysis on power quality field measurement of the Grid connected photovoltaic power plant.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2006.05a
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• pp.272-277
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• 2006

High speed electric trains have nonlinear loads including converters and inverters for the contol synchronous motors. Harmonic field measurements have shown that the harmonic contents of a waveform varies with time. Direct application of the harmonic assessment to the snapshot measurements would result in ambiguous conclusions depending on which instant is sampled. A cumulative probablistic approach is the most commonly used method to solve time varying harmonics. This paper provides an in depth analysis on harmonics field measurement of the high speed electric train loads, harmonics assessment by the international harmonic standards IEC 61000-3-6 and IEEE std. 519-1992, and harmonics simulation using EDSA program for the case study.