• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.11
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• pp.1022-1027
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• 2005

An experimental study is conducted to investigate the characteristics of the ion wind generated by the electric field between a needle electrode and the parallel plate electrodes. The ion wind enhances heat and mass transfer between the surface and the surrounding gas. Moreover such enhancement makes no noise or vibration. This study is conducted to develop the electronic cooling device. The measured gas velocities and heat transfer coefficients are proportional to the applied voltage. The heat transfer coefficient can be increased as compared with a natural convection. The maximum enhancement of heat transfer obtained in this system is $47\%$ for 3 W in heat transfer rate.

• Proceedings of the KIEE Conference
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• 2002.07a
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• pp.475-477
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• 2002

본 논문에서는 765kV 송전선로의 일부구간에서 발생되고 있는 풍소음의 대책으로 개발된 저풍소음 도체를 소개하고 이 도체방식을 개발하기 위해 수행된 전기환경장해 및 풍소음 저감 영향에 대한 시험결과를 제시하고 있다. 저풍소음 도체는 우수한 풍소음 저감기능을 가지면서도 기존 전선에 비해 추가적인 전기환경 문제가 발생되지 않아야 하는데, 기존 전선과 달리 전선 주위에 돌기부가 있어서 전계 집중에 따른 환경장해 발생의 우려가 있다. 이러한 이유 때문에 전기환경 모의시험설비인 코로나 케이지를 이용한 코로나 발생 특성 시험을 수행하여 환경설계기준 만족 여부를 확인하였으며, 실규모 시험선로를 이용한 장기 실증시험을 실시하여 송전선로 주변에서 실제 발생 가능한 라디오 장해와 같은 전기환경 장해량에 대한 평가를 실시하여 풍소음 저감효과와 환경설계기준에 만족하는 결과를 얻을 수 있었다.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.4
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• pp.74-80
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• 2003

Ionic wind is produced by a corona discharge when a DC high voltage is applied across the point-to-plane gap geometry. The corona discharge phenomena have been investigated in several beneficial application fields such as electrostatic cooling, ozone generation, electrostatic precipitation and electrostatic spraying. Recently ionic wind might be used in aerodynamic, for example, heat transfer, airflow modification, and etc. In this work, in order to analyze the control behavior of the velocity and amount of ionic wind produced by the positive DC corona discharges. The ionic wind velocity was measured as a function of the applied voltage, diameter of the punched hole on plate electrode and separation between the point-to-plate electrodes. As a results, the airflow is generated from the tip of needle to the plate electrode in the needle-to-punched-plate electrode systems. The ionic wind velocity is linearly increased with an increase in applied voltage and ranges from 1 to 3 m/sec at the locations of 100-200 mm from the punched-plate.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.24 no.9
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• pp.693-698
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• 2012

In the present work, numerical analyses of broadcasting LED light with ion wind generator have been carried out for enhancement of cooling performance. Ion wind generator is produced and experimented before analysis. With the use of result of experiments, broadcasting LED light model is computed. Ion wind velocity into LED light is varied with 0~3 m/s. Based on the numerical results, the area of duct-type ion wind generator was designed to reduce the volume flow rate of ion wind. The modified inlet geometry shows sufficient cooling capability. And, through modified ion wind generator, the volume flow rate of ion wind has been largely reduced.

• Electric Engineers Magazine
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• v.250 no.6
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• pp.28-31
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• 2003

765KV 송전선로는 실규모 시험선로를 통한 장기시험을 통해 코로나로 인한 소음, 라디오 잡음뿐만 아니라 전계, 자계, 풍소음 등에 대한 충분한 검토를 통해 환경친화적인 설계를 통해 건설되었다. 표는 500KV급 및 765KV급 선로와의 비료자료로서 Gmax는 환경장해의 주요인자로 작용한다.

• Journal of Astronomy and Space Sciences
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• v.25 no.1
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• pp.25-32
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• 2008

Using the solar wind data of 2000 observed by ACE, We classified the interplanetary shock on basis of shock driver. We examined the physical properties of shock drivers such as the ratio of charge states(O7/O6) and thermal index$(I_{th})$. Most of 51 interplanetary shocks are driven by interplanetary coronal mass ejections(ICME; magnetic cloud and ejecta) and high speed streams. According to the test of temperature(O7/O6) and $I_{th}$, we found that ICMEs originated from region with hot source in corona.

• Journal of Astronomy and Space Sciences
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• v.26 no.4
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• pp.439-450
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• 2009

Recurrent enhancements of relativistic electron events at geosynchronous orbit (GREEs) were observed in 2006. These GREE enhancements were associated with high-speed solar wind streams coming from the same coronal hole. For the first six months of 2006, the occurrence of GREEs has 27 day periodicity and the GREEs were enhanced with various flux levels. Several factors have been studied to be related to GREEs: (1) High speed stream, (2) Pc5 ULF wave activity, (3) Southward IMF Bz, (4) substorm occurrence, (5) Whistler mode chorus wave, and (6) Dynamic pressure. In this paper, we have examined the effectiveness about those parameters in selected periods.

• Journal of KSNVE
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• v.6 no.1
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• pp.89-95
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• 1996

If the transmission line voltage is greater than 500kV, audible noise (AN) and hum noise (HN) due to corona discharges on the conductor would be an important design factor for the conductor selection of transmission line. Also there is an aeolian noise: wind noise(WN) from the tower and the conductor due to wind. This paper presents the results of a statistical analysis of audible noise, hum noise, aeolian noise of 6-480mm$^{2}$ conductor bundle in KEPRI 765kV Test Transmission Line which was constructed to develop 765kV double circuit AC transmission line for the first time in the world. The result of the analysis shows that 6-480mm$^{2}$ conductor bundle and tower satisfy configuration the audible noise design criterion of 50dB(A).

• Journal of Satellite, Information and Communications
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• v.6 no.2
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• pp.97-101
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• 2011

Interplanetary space between Sun and Earth is area of flowing very fast solar wind which is contained X ray, flare, corona mass, etc. occurred Sun surface to Earth. This solar wind is affected directly to Earth magnetosphere and ionosphere so that this bring out broadcasting and communication interruptions, satellite operation obstacles and power gird defects and etc..Solar wind flow in interplanetary space is measured as solar wind speed, density and direction by measuring scintillation value to be produced during radio source is passed through solar wind. The wider effective collective areas and the more radio sources, accuracy of solar wind measuring is got higher. Function test was performed using 3 tiles which was manufactured as prototype. Restriction of quantity of tiles, test was performed to confirm whether measured beam pattern is complied with requirement or not. In this paper, it is shown design and their specification of ground interplanetary radio measurement system as well as technical issues and resolutions which were raised during design phase. Also result of function verification test using prototype is suggested. It is confirmed that measured beam pattern was met with requirement.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.16 no.4
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• pp.318-323
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• 2004

When a strong electric field is applied between a sharply curved electrode and a blunt surface, the corona may result in a gas movement in the electrode gap which is directed toward the blunt surface. That is called the corona wind. It enhances heat and mass transfer between the surface and the surrounding gas. Moreover such enhancement causes no noise or vibration, which can be applied in complex, isolated geometries, and allows simple control of surface temperatures. This paper examines the relationship between the corona wind and the relative humidity. The facility consists of high voltage power supply thin tungsten wire, plate electrode, multimeter, microammeter and flow meter. Gas velocity is a linear function of voltage, relative humidity and is proportional to the square root of the current. The maximum velocities for the positive and negative corona discharge are 1.9 m/s (2.74 CMM/m), 1.5 m/s(2.15 CMM/m), respectively.