• Proceedings of the KIEE Conference
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• 2000.11a
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• pp.232-235
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• 2000

Design and experiments of a nondestructive system to inspect deterioration of ACSR-OC (ACSR Outdoor Cross-linked Polyethylene Insulated Wire usually used in HV overhead distribution lines presented in this paper. ACSR-OC conductor built to pollutants air for a long period would be easily progress to corrode so that it may lead to the reduction of the effective cross section area of conductors. A fault diagnosis system consisting of a solenoid sensor, a constant current source with RF frequency signal processing unit and a motor driver/controller designed and implemented. This instrument can dot the sensor output variation due to deterioration corrosion, continuously. As a result, it was shown such corrosion detector can readily be utilized estimating the diameter change due to deterioration overhead distribution lines and in giving an warning or inform before severe aged conductor lead to fail.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1453-1458
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• 2006

KTX Railway rolling stock wheel run its course to corrode, deteriorate and wear away through out the time. So it is natural that the performance and ability of wheel gets declined. The frequency characteristic analysis were accomplished to above trend and shock wave flow to wheels were examined. The result will be used to find Railway rolling stock wheel crack and maintenance method hereafter.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.44 no.6
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• pp.9-14
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• 2012

Currently a variety of efforts to conserve and restore the injured the Annal of the Joseon Dynasty are continued and many studies about the aging pathway of the beeswax-treated volume have being progressed. In this study, two chambers were set up to assess the influence of VOCs(Volatile Organic Compounds) generated in process of beeswax deterioration. One chamber was closed and the other was continuously ventilated in order to remove the VOCs. In results, the acid compounds of beeswax-treated Hanjis aged in closed chamber was more than that aged in ventilated chamber. The folding endurance of beeswax-treated Hanjis aged in closed chamber was lower than that aged in ventilated chamber. Accumulated acid compounds of beeswax-treated Hanji in closed chamber may cause accelerated aging and strength decrease. In conclusion, accumulated acid compounds can accelerate the aging of beeswax-treated Hanji and cause the severe deterioration of inside of beeswax-treated volume. Therefore, to preserve more safely beeswax-treated volumes of the Annals of the Joseon Dynasty, it is essential that VOCs emitted from beeswax-treated volume are ventilated.

• Journal of Korea Technical Association of The Pulp and Paper Industry
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• v.45 no.6
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• pp.10-16
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• 2013

This study aims to carry out the final evaluation on the deterioration stability of dewaxing and strengthening treatments devised to conserve and restore the beeswax-treated volumes of the Annals of the Joseon Dynasty. Thus, this study artificially deteriorated dewaxed Hanji, strengthened Hanji and beeswax-treated Hanji with optimized processing conditions applied, and comparatively analyzed the deterioration characteristics of each kind of Hanji. As a result of this study, it turned out that there was the loss of physical strength and the value of $L^*$ was increased and the values of $a^*$ and $b^*$ were decreased from removing beeswax after dewaxing by supercritical fluid extraction (SFE). Also deteriorated strength during dewaxing was reinforced by strengthening treatment with methylcellulose and it showed higher strength than beeswax-treated Hanji. From the evaluation on deterioration stability after dewaxing and strengthening, it turned out that deterioration stability of strengthened Hanji is the superior. Therefore, it is presumed that conservation of aged beeswax-treated Hanji can be improved and extended when dewaxing and strengthening are applied under optimum conditions.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2005.07a
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• pp.562-563
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• 2005

In case of aged porcelain, the failure in basic performance tests happened in cool-heat tests. Based on this characteristic, we studied the method predicting failure phenomena through more severe accelerated cool-heat ageing and accelerating thermal mechanical performance tests. Test results indicated that the thermal stress by temperature gradient was more severe parameter than thermal stress by quenching cycles within a category of standard or accelerating methods. And there is no the deterioration of statistic strength, but the deterioration of strength according to accelerating tests is serious.

• Journal of Sasang Constitutional Medicine
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• v.22 no.1
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• pp.49-58
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• 2010

1. Objectives: The purpose of this study is to find out the Anti-Oxidative effects of Soyangin Hyeongbangpaedok-san(HBP) in kidney and spleen cells of aged rats. 2. Methods: Aged rats used in this experiment were 6, 52, 68 weeks old. Each age group was divided into three groups again. One group was given no treatment, another group was dosed normal saline and the other group was dosed HBP decoction. The antioxidant effects of HBP decoction were measured by the levels of SOD, GSH, MDA and NO. 3. Results: and Conclusions: 1) The activity of SOD was significantly increased in kidney cells of 68w-HBP group. Deterioration of the activity of SOD in kidney cells was significantly suppressed according to increasing in age of the week. 2) The level of NO was significantly decreased in kidney cells of 68w-HBP group. Deterioration of The level of NO in kidney cells was significantly suppressed according to increasing in age of the week. 3) The activity of SOD was increased in spleen cells of 52w and 68w-HBP group. 4) The level of GSH was significantly increased in spleen cells of 68w-HBP group.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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• v.14 no.6
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• pp.43-50
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• 2000

Design and experiments of a nondestructive testing system with a solenoid eddy current sensor to inspect deterioration of ASCR-OC (ACSR Outdoor Cross-linked Polyethylene Insulated Wires) usually used in HV overhead distribution lines in domestic areas in presented in this paper. Through corrosion mechanisms and deterioration results for ACSR-OC conductors are examined, it is shown that corrosion may lead to the reduction of the effective cross section area of conductors is proposed. The measurement system consisting of a constant current source with a RF frequency, a signal processing unit and a motor driver/ controller is designed and implemented. This instrument has such capabilities as detecting the sensor output and estimating diameter change of the testing conductors, continuously. As a result, it was verified that such corrosion detector system with an eddy current sensor can be shown good effectiveness for estimating the serious faults due to deterioration in overhead distribution lines and giving an early warming before severe aged conductor may lead to fail.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.63 no.2
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• pp.297-305
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• 2014

Nowadays new water supply projects have been on the decline as the water-power constructions have saturated, which means that the existing power equipment have slowly aged and they require more efforts to maintain the system performance. An effective asset management method of power equipment has become a great necessity from both economical and technical aspects. To be balanced, the asset management should look into all three parts: management, engineering, and information. The purpose of this paper is to study a Risk-Based Maintenance (RBM) matrix method through the deterioration evaluation algorithm for an efficient reliability assessment of oil-immersed power transformers by considering both asset management and technical evaluation. Make use of this result, the equipment will be decided to be replace or repair otherwise on service.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2007.06a
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• pp.538-540
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• 2007

A detailed study on aged sleeves for old transmission lines was carried out to clarify the deterioration of sleeves and the condition of installation. A lot of removed aged sleeves from transmission lines were investigated. Many biased installed cases and corrosion of steel sleeve part were found. These defects can cause a serious accident such as blackout during operating. The detailed results were presented in the text.

• Journal of the Korean Institute of Electrical and Electronic Material Engineers
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• v.20 no.11
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• pp.1009-1014
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• 2007

A detailed study on aged sleeves for old transmission lines was carried out to clarify the deterioration of sleeves and the condition of installation. A lot of removed aged sleeves from transmission lines were investigated. Many biased installed cases and corrosion of steel sleeve part were found. These defects can cause a serious accident such as blackout during operating. The temperature distribution within sleeve of ACSR conductor was precisely measured and examined, conducted as part of series of studies on large currents in transmission lines. According to measurements of the conductor temperature near a joint(sleeve and clamp), the electrical resistance of joint is lower than that of the same length conductor. The detailed results were presented in the text.