• Proceedings of the KSR Conference
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• 2003.10c
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• pp.623-627
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• 2003

Aging and failure of motor insulation depend on the stresses imposed on it. The insulation life time depends on the severity of the stresses. The electrical aging by transient surge is very important to traction motor in EMU(electric multiple unit). This paper presents the insulation characteristics of stator coil by transient surge from inverter. There are several nondestructive tests available for checking the condition of motor insulation, the probable extent of aging, and the rate of which aging is taking place. So the insulation characteristics of stator coil were each analyzed by measurement of leakage current, dielectric loss($tan{\delta}$), capacitance, polarization index(PI) and partial discharge. The method of diagnosis is able to analyze the aging condition and predict the life of the traction motor in EMU.

• Proceedings of the KIEE Conference
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• 2003.07b
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• pp.1285-1287
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• 2003

The aging of the insulation reduces the electrical and mechanical strength of the insulation. At same point, a voltage surge or mechanical shock from a traction motor start will fracture or break down the insulation. To achieve the expected life usually requires extensive laboratory evaluation of the insulation systems and the use of accelerated aging tests. There are several nondestructive test available for checking. the condition of motor insulation, the probable extent of aging, and the rate of which aging is taking place. So the insulation characteristics of stator coil were each analyzed by measurement of dielectric loss($tan{\delta}$), capacitance and partial discharge. The method of diagnosis is able to analyze the aging condition and predict the life of the traction motor.

• Journal of Korean Medical classics
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• v.12 no.2
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• pp.176-183
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• 1999

Each life has its own properties that distinguish one another. With this property, Oriental medicine suggests original diagnosis and treament. Our process of aging shows typical outline of cycle, i. e. from one's birth to death. Understanding the life cycle of men gives us very good hint to predict one's state of health, possible diseases, characteristics of disease in each term of his/her life cycle. It's because body and mode of diseases change according to age. Aging starts when $\breve{U}$m Essence(陰精)-the essence one receive from parents-dries up or when Deficient Fire(虛火) soars. Parts that compose our body-bones, muscles, flesh, etc.-gradually weaken and worn out as they no longer get support from Yang-Ki(陽氣), In "Yellow Emperor's Classic", aging starts around one's forties when $\breve{U}$m Essence(陰精) is reduced to less than half. However, what is usually accepted is that women start aging from 49 and men 64, regarding significant geriatric disease. As it is mentioned, aging starts with exhaustion of $\breve{U}$m Essence(陰精) which results in soaring Deficient Fire. Main symptoms are weak mental state due to Sin(神) disorder, and weak physical state due to Spleen and Stomacn(脾胃) disorder. Main principle in treating and preventing diseases related to aging is preserving $\breve{U}$m Essence(陰精), as well as fortifying Ki and Blood(氣血). To do this, Lung(肺)-which collects $\breve{U}$m Essence(陰精), and Kidney(腎) stores-which stores $\breve{U}$m Essence(陰精).

• Proceedings of the KIEE Conference
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• 2005.10b
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• pp.573-575
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• 2005

In the steel industry, a steel melting electric arc furnace is used to produce both carbon and alloy steels. Steel scrap which is charged into the furnace is heated by means of electric arc between graphite electrodes and the scrap. In this melting process, current is supplied to the furnace through HCC(high current cable) which connect the furnace and transformer. Four HCCs are assigned to each phase in our system to divide the current. Since a sudden cable breaking result in the shutdown of melting process, an aging detection of HCC is very important for both an improvement of productivity and cost reduction. In this paper, the aging of the HCC is estimated by using the current ratio between four HCCs.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.26 no.2
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• pp.151-157
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• 2013

In this paper, properties of pattern using LBG (Linde-Buzo-Gray) Algorithm was explored including the exactness of K-means algorithm and process time of EM (Expectation Maximization) algorithm in order to develop analysis algorithm of partial discharge pattern in a cable using acoustic data analysis system. Partial discharge was measured by generating inner fault due to lamination of XLPE which is used for cable insulation material. Discharge pattern was analysed by changing the number of swarm article to 2, 4, and 6 in order to interpret swarm structure and properties.

• Proceedings of the KIEE Conference
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• 2002.07c
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• pp.1698-1700
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• 2002

Recently, the HFPD measurement methods that detect high frequency bandwidth of frequency components of partial discharge pulses are proposed and many studies are carried out. The HFPD measurement method is able to detect partial discharge signal in active line, therefore this method has a merit that can does condition monitoring of power equipments and measure growth state of partial discharge erosion with on-line and real time. In this study, the radiated HFPD signals are detected by antenna and aging diagnosis is executed with a neural network algorithm. As a result of this study, the aging diagnosis of insulation material using neural networks is possible.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.55 no.3
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• pp.115-118
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• 2006

In the steel industry, a steel melting electric arc furnace is used to produce both carbon and alloy steels. Steel scrap which is charged into the furnace is heated by means of electric arc between graphite electrodes and the scrap. In this melting process, current is supplied to the furnace through HCC(high current cable) which connect the furnace and transformer. Four HCCs are assigned to each phase in our system to divide the current. Since a sudden cable breaking result in the shutdown of melting process, an aging detection of HCC is very important for both an improvement of productivity and cost reduction. In this paper, the aging of the HCC is estimated by using the current ratio between four HCCs.

• Proceedings of the KIEE Conference
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• 2000.07b
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• pp.1371-1373
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• 2000

In this paper, the complex accelerating degradation of traction motor driven with VVVF controlled inverter were performed on the form coil samples with the 200 Class insulation system. in order to evaluate the reliability and the long-term life. After aging, the dielectric and PD properties were investigated on the 10 cycles aging sample in the range of $20{\sim}160[^{\circ}C]$ and AC $250{\sim}2250[V]$ to diagnosis the condition of end-life and find the dominative factors of degradation.

• International Journal of Safety
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• v.9 no.2
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• pp.11-15
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• 2010

Infrastructures in Japan constructed mostly in high economic growth period become elder & elder, and the troubles & accidents caused by the aging increase. Though investment for the renewal is necessary, the shortage of public fund delays the action. Besides, we expect the decrease of the population that means the decrease of the engineers who take care of social infrastructures. Thus, it is necessary for us to develop Advanced Management system of social Infrastructures (AMI) to realize the efficient and economical operation. Our concept of AMI consists of using ICT, PI (Public Involvement) and establishment of O&M diagnosis system. We expect AMI will support to realize the appropriate repairing, preventive maintenance based on the actual performance, accidents & dangerous experience and education & training of the workers. In this paper, development of AMI for the waste disposal facility as a first example of infrastructures will be shown.

• Proceedings of the KIEE Conference
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• 1993.07b
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• pp.584-587
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• 1993

Mica, which have a good thermal and electrical characteristics, while will cleave easily at these layers. In order to bond mica materials soldily, mica/epoxy composite insulation materials were developed for generator stator winding. There are lots of problems such as delamination and partial discharge of these insulation materials caused by mechanical, electrical and thermal aging. Several experiments have been conducted in order to find the useful diagnostic parameters from the partial discharge phenomena by applying a new measurement techniques. this paper deals with the partial discharge pulse characteristics, which may be a useful diagnostic concept in predicting insulation condition of generator stator insulation materials. Long term insulation aging test shows that partial discharge phase angle an magnitude are identified as one of the main key techniques for insulation diagnosis on generator stator winding.