• 전기학회논문지
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• 제58권5호
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• pp.994-998
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• 2009

Existing cooling technologies no longer provide adequate heat dissipation due to excessive heat generation caused by the growing component density on electronic devices. An ionic gas pump can be used for the thermal management of micro-electronic devices, since the size of pump can be reduced to a micrometer scale. In addition, the gas pump allows for gas flow control and generation without moving parts. This ideal property of gas pump gives rise to a variety of applications. However, all these applications require maximizing the wind velocity of gas pump. In this study a barrier discharge type gas pump, with a needle-shaped corona electrode instead of a plate-shaped corona electrode, has been investigated by focusing on the corona electrode shape on the wind velocity and wind generation yield. As a result, the enhanced wind velocity and wind generation yield of 1.76 and 3.37 times were obtained with the needle-shaped corona electrode as compared with the plate-shaped corona electrode of the proposed barrier discharge type gas pump.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제48권5호
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• pp.373-378
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• 1999

In order to analyse the degradation mechanism of polymer materials for outdoor condition, FRP laminate was exposed to high temperature and ultraviolet rays. Then, thedegradation process was evaluated by comparing contact angle, surface potential decay, and polarity effect respectively. Especially, the analysis of surface degradation phenomena by corona charging method showed the exact correlation with the result of chemical properties. Therefore we can confirm that the application of corona charging method on the identification of degradation process is very useful. If this method is usedin degradation studies on the polymer surface, it will be more effective on the surface analysis of polymer insulators. With corona charging method and chemical spectrum analysis, it was possible concretely to define degradation process on the polymer surface exposed at the situation of different environmental conditions.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2004년도 하계학술대회 논문집 Vol.5 No.1
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• pp.503-506
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• 2004

In this paper we investigated the changes of surface hydrophobic characteristics on silicone rubbers by corona discharge treatment and also investigated the distribution and the behavior of low molecular weight(LMW) silicone fluid which was extracted by solvent-extraction with gel permeation chromatography(GPC). It was shown that contact angle was $110.5^{\circ}$ on initial sample but contact angle was approximately decreased to $10^{\circ}$ after 45 minutes. However the surface hydrophobic characteristic on silicone rubbers which were removed from corona discharge was recovered within 5 hours. It was shown that corona discharge insured the increase of diffusible LMW chains, which could lead to recover the surface hydrophobicity. The surface hydrophobic characteristics on silicone rubbers and the recovery mechanism based on our results were discussed.

• 유통과학연구
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• 제19권11호
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• pp.27-36
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• 2021

Purpose: COVID-19, government regulation and social media have changed many aspects of life including consumption behavior. The influence of social media by spreading massive news about COVID-19 also have the impact toward emotions threat, perceived risk, and perceived value of consumption behavior in Bengkulu Province, Indonesia. This research aims to analyze the extent to which changes in the consumption behavior, mainly for purchasing of corona prevention products through indirect distribution channels. Research design, data and methodology: This research was descriptive quantitative using the IPA method with sample of people in Bengkulu Province. This study obtained 208 respondent data from questionnaires and tested the validity and reliability with corrected-item total correlation method. Results: The study found that COVID-19 pandemic and government regulation variable were in quadrant II, in quadrant III there were social media variable, emotions threat and perceived risk. Meanwhile, in quadrant IV there were perceived value variable. Conclusions: The findings indicated that COVID-19 and government regulation are the most variable that influence people to buy corona prevention product, meanwhile perceived value is the less influence variable. Therefore, government and marketers have to prepare strategic plan in order to raise people awareness to avoid corona by buying corona prevention product.

• 전기의세계
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• 제29권8호
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• pp.532-537
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• 1980

Effect of Argon and Sulfur hexafloride in the transformer oil are experimented under non-uniform A.C. electric field. The result has shown that the corona frequency and corona charge quantity in liquid dielectrics were varied with gas condition in the oil and affected by the additives. SF$_{6}$ that has the effects of pressure and electrical negative characteristic is the most effective. The corona is considered to be the breakdown of bubble produced by gas contained in the oil or by dissociated ion of the oil molecules.s.

• 전기의세계
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• 제21권4호
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• pp.22-26
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• 1972

The vibration of power lines in rainy environments was researched using the concentric cylindrical gap to which D.C. voltage was applied. Consequently, it has been solidly conformed that the vibration of power lines begins at threshold voltage of corona, and that the amplitude of the vibration increases as the numbers of falling water drop per unit time increase. The vibration phenomen take place in straight line, elliptic or circular motion as voltage is applied the numbers of vibration nearay accord with the elastic vibrarion theory.

• Journal of applied mathematics & informatics
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• 제9권1호
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• pp.341-347
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• 2002

Given operators X and Y acting on a Hilbert space H, an interpolating operator is a bounded operator A such that AX = Y. An interpolating operator for n-operators satisfies the equation $AX_i = Y_i$, for i = 1,2…, n. In this paper, we investigate Hilbert-Schmidt interpolation problems in tridiagonal algebra by connecting the classical corona theorem.

• Journal of applied mathematics & informatics
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• 제42권4호
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• pp.777-783
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• 2024

Topoloical index is a numerical quantity which is correlates to properties of chemical compound . In this paper, we define operator graph namely, Edge ss-corona graph and we study structured properties of that graph. Also, establish the upper and lower bounds for First Zagreb index, Second Zagreb index, First Gourava index, SK₁ index, Forgotten topological index and EM₁ index of edge SS-corona graph.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1995년도 하계학술대회 논문집 C
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• pp.1105-1107
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• 1995

In order to examine closely the corona degradation of epoxy composites, the corona electrets which are formed by appling high voltages, 300[kV/cm], to epoxy composites are experimented to measure TSC(thermally stimulated currents) at the temperature range of $-160{\sim}200[^{\circ}C]$ and to investigate the various aspects due to corona degradation in this study.

• 대한전기학회논문지:전기물성ㆍ응용부문C
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• 제54권9호
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• pp.421-426
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• 2005

A wire-plate discharge system with a slit barrier has been proposed and investigated experimentally by focusing on the discharges on the slit barrier and ozone generation characteristics. This wire-plate discharge system with a slit barrier can generate an intensive corona discharges, and produce corona discharge twice, once from the corona wire electrode and second time from the surface and the slits of the slit dielectric barrier. As a result this propose wire-plate discharge system with the slit barrier can produce greatly increased ozone than without the slit barrier. This type of wire-plate discharge system with the slit barrier could be used for effective ozone generation as a means with retard to the removal of pollutant gas