• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.1
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• pp.67-74
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• 2000

This paper presents the analysis of partial discharge signals according to the particle states in GIS, for preventing the insulation failure and recognizing the particle states. In this paper, four states of particle (particle on electrode, particle on enclosure, particle on spacer and crossing particle) were simulated. And $\Phi$-Q-N distribution of partial discharge signals was analyzed and the statistical operator of the $\Phi$-Q distribution was analyzed. As a result, it was found that the states of particle were distinguished by analysis of the $\Phi$-Q-N distribution and the statistical operator of the $\Phi$-Q distribution.

• The Proceedings of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.1 no.2
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• pp.62-69
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• 1987

In the thesis research on the C.T.I for the borne by tracking phenolic resin, electolytic errosion appearance of electrode materials causes the part of electrode to increase the failure of tracking. $\circled1$ In the material of insulation in which C.T.I has 350 degree or so, We can obtain the constant value by Cu.Zn electrode than Pt electrode. $\circled2$ C.T.I value has noting to do with resistance rate of electrolyte. $\circled3$ As the contact angle of interface grow, the starting electric stress of corona and the value of C.T.I increase.

• Proceedings of the Korean Institute of IIIuminating and Electrical Installation Engineers Conference
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• 2005.05a
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• pp.47-50
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• 2005

In this paper, we investigate a filtering technique to reduce the adverse effect of long motor leads on H-bridge cascaded 7-level inverter fed ac motor drive. The switching surge voltage becomes the major cause to occur the insulation failure by serious voltage stress in the stator winding of high voltage induction motor. However, the effect of switching surge appears un seriousin high voltage induction motor than low voltage induction motor. Consequently, we demonstrated that the filter connected to the motor terminals greatly reduces the transient voltage stress and ringing, moreover we show lowers the dv/dt of the inverter switching pulse. The results of simulation show the suppression of dv/dt and the reduced peak voltage at the motor end of a long cable.

• Structural Engineering and Mechanics
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• v.5 no.4
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• pp.339-353
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• 1997

Fiber reinforced plastic (FRP) rods provide certain benefits over steel as concrete reinforcement, such as corrosion resistance, magnetic and electrical insulation, light weight, and high strength. FRP composites can be combined with a steel core to form hybrid reinforcing rods that take advantage of properties of both materials. The objective of this study was to characterize the bond behavior of hybrid FRP rods made with braided epoxy-impregnated aramid or poly-vinyl alcohol FRP skins. Eleven rod types were tested using two concrete strengths. Specific topics examined were bond strength, slip, and type of failure in concentric pull-out tests from concrete cubes. From analysis of identical pull-out tests on both hybrid and steel rods, information on relative bond strength and behavior were obtained. It is concluded that strength is similar but slip in hybrid rods is much higher. Hybrid rods failed either by pull-out or splitting the concrete block (with or without yielding of the steel core). Experimental data showed consistency with similar test results presented in the literature.

• KIEAE Journal
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• v.16 no.6
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• pp.77-82
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• 2016

Purpose: Almost every research carried out in our country against the natural disaster is focused on the temporary facilities such as temporary housing, emergency shelter and as a result, it is very hard to find out researches on the ordinary houses which installed integrated systems of hazard-resistant against the natural disaster. Method: To conduct this research, categorizing process for design, structural, environmental and installation elements found in the Hazard-Resistant and Reduction House built for sale in Japan was performed. Result: In this study, several design concepts and subordinate items are recommended for hazard-resistant housing. First, design concept of 'Preparedness' which means security and access to the storage storing goods especially food & beverage for the emergencies is needed. The subordinate items consist of security of stocking space, diversified and circular storage system, and safety storage system. Second, design concept of 'Security' which means security of physical safety space and rapid recovery to returning to daily life against natural disaster is needed. The subordinate items consist of many items including not only structure and facilities but also architectural design method. And finally, design concept of 'Maintenance, Support and Return' which means minimizing the physical and psychological damages and support safety and physical conditions of the victims from the impact of the disaster to returning to daily life is needed. The subordinate items consist of high efficiency insulation/airtightness design, microclimate design, combination of photovoltaic system and storage battery, non-power appliance system against the power failure, storing system for drinking water, rainwater storing and utilization system.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2010.06a
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• pp.104-104
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• 2010

With the advent of nano-particle fillers in insulating materials, the insulating materials of superior quality have come to fore. In the recent past, nanocomposite LDPE/XLPE (Low Density Polyethylene/Cross Linked Polyethylene) power cable dielectrics have been synthesized. A preliminary evaluation of these new class of materials seem to show that, addition of small amounts of sub-micron inorganic fillers improved the dielectric properties of the composite, in particular, the volume resistivity, and the DC breakdown strength. The thermal behaviour, for example, the stability of composites against decomposition and ensuing electrical failure, do not seem to have been addressed. In a conventional XLPE insulated cable, the average thermal breakdown strength and maximum temperature at the onset of breakdown were seen to be markedly lower than the corresponding intrinsic breakdown strength and decomposition temperature. In this page, analysis of DC Breakdown of nano-composite insulating material for HVDC Cable is introduced.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.3
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• pp.273-280
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• 2007

In this paper, the ZnO surge arrester performance of power distribution class has been studied under different manufacturing conditions such as housing materials(polymeric, porcelain), interface sealants and one-body molding type. In the recent years, the polymeric ZnO surge arresters have been developed and put into operations based on their excellent characteristics. For polymeric surge arresters, the inner gas volume is extremely small, especially in solid insulation polymeric arresters there are not any gas volume inside arresters in the structure due to polymeric materials are filled into the internal gas volume. The sealing integrity is related to safe operation of surge arrester, the prime failure reason of porcelain housed arresters is moisture ingress. In this paper, the sealing integrity of polymeric surge arresters is investigated with moisture multi-aging test and ingress test. The evaluation techniques are used to inspect the sealing integrity of polymeric arresters, including leakage current, surface temperature, reference voltage and dissipation factor.

• Proceedings of the KIEE Conference
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• 1996.07c
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• pp.1765-1768
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• 1996

It is well known that the degradation transformer oil is mainly effected to the failure of transformer. In this paper it is discussed the characteristics of the degradation sensor checking transformer oil condition in live line. The degadation sensor composed with base ring, electrodes and porous ceramic passed through the transformer oil and checked the transformer oil condition with sensor's leakage current. It is important to minimize the leakage current of base ring and connection parts. To investigate the leakage current of base ring and connection parts it is examined the characteristics of V-T-I and DC 2 KV and other examinations. It is verified that ionized transformer caused by the expansion of oil temperature increase in the leakage current of porous ceramic sensor. It is certificated that the leakage current of other parts of porous ceramic is very small (about 2 %) than the porous ceramic and it is confirmed that the leakage current in porous ceramic is changed sensitively according to the new oil(NO) and and the degradation oil(DO).

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.17 no.2
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• pp.66-72
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• 2003

The global assessment system for medium voltage power cable systems has been developed The minimum purpose of diagnostic activity is the economic discrimination and maintenance of bad cables which is likely to cause cable system failure. I have adapted the Aging Time Constant Method to construct the power cable assessment system for the diagnostic purpose. From the field application test and breakdown test results, it could be concluded that the diagnostic system was successful art convenient for the discrimination and maintenance of the bad cables, which is likely to fail sooner or later, economically.

• Proceedings of the KSME Conference
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• 2000.04a
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• pp.121-126
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• 2000

Metal/Ceramic structures have many attractive properties, with great potential for applications that demand high stiffness, as well as chemical and biological stability, thermal and electrical insulation. They are currently in use for mechanical and thermal protection in cutting tool and engine parts. With all their great advantage, ceramics suffer from one major problem they are brittle, and are especially susceptible to cracking from surface contacts. Delamination at the interfaces with adjacent layers is a particularly disturbing problem, and can cause premature failure of a composite system. so determination of adhesive properties of coating is one of the most important problems for the extension of the use of coated materials. In this work, mechanical characteristics of Interface of ceramic/Metal composites are evaluated by means of hardness test, indentation test apparent interfacial toughness and bonding strength test. The interface indentation test provides a relation between the applied load(P) and the length of the crack(a) created at the interface between the coating and the substrate.