• Journal of the Korea Concrete Institute
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• v.14 no.2
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• pp.148-155
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• 2002

This research investigates the moisture and aging effects of wastepaper fiber-cement composites. Wastepaper fibers is obtained by a dry process. Wastepaper fiber-cement composites was manufactured by the hatscheck process. The effects of moisture and aging on the performance of wastepaper fiber-cement composites were investigated through accelerated laboratory tests simulating the effects of moisture sensitivity and wet-dry cycles as well as freeze-thaw cycles and long-term drying. They were shown to possess acceptable moisture and aging performance compared with virgin fiber cement composites.

• 전기의세계
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• v.48 no.12
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• pp.12-17
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• 1999

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.849-852
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• 2008

In the wheel tracking test to evaluate abrasion resistance for concrete surface coating materials applied parking lot, weight of the wheel, test temperature, scattered sand amount, wheel speed, etc. various test condition is used for reliable evaluating the abrasion resistance performance of surface coating materials and the results depends on the test condition. In this paper, we carried experimental study as following on abrasion resistance with 2kinds of different environmental conditions. - Commons : real car tire with 300kg of load, 5km/h of speed, 80,000 cycle. - Control A : no other deterioration condition - Control B : scattering 1.0g of sand per every 30rounds from 1m height.

• Journal of the Korea institute for structural maintenance and inspection
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• v.16 no.6
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• pp.82-92
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• 2012

This study proposed a new non-destructive evaluation method for concrete bridge deck deterioration using ground penetrating radar (GPR). To calculate dielectric constant of the concrete bridge deck, an extended common mid-point (XCMP) method was developed for a two-layered structure using an air-coupled GPR antenna setup. The deterioration conditions of the concrete bridge deck such as deterioration depth was evaluated based on the dielectric constant and surface-to-average dielectric constant ratio of the concrete bridge deck. A GPR field test was conducted on an old concrete bridge with asphalt concrete surfacing to validate the new evaluation method. The test results showed that the newly proposed method estimated pavement thickness and deterioration depth of the concrete deck in a reasonable level.

• Journal of Korea Foresty Energy
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• v.21 no.2
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• pp.34-42
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• 2002

This research was carried out to investigate water repellent effectiveness of natural oil treated wood. Linseed oil, castor oil, olive oil, bean oil, perilla oil and sunflower oil were used in this test. For evaluation of water repellent of natural oil treated wood, moisture absorption test, water-drop contact angle test and color difference test of accelerated decomposition by UV and water were used. The moisture absorption amount of natural oil treated wood was less than untreated wood until 3 hours, but it was increased with time, there was no big difference with oil treated wood and untreated wood after 48hours. Oil treated wood and untreated wood showed big difference on contact angle test. It was no big difference by kind and oil concentration. Natural oil treated wood did not showed stability on the weather aging test. Contact angle test could be used on evaluation of wood surface status treated with natural oil.

• Journal of the Korean Society for Nondestructive Testing
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• v.24 no.5
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• pp.525-531
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• 2004

In this paper, the concept of infrared thermography(IRT), the principle of measurement of IRT and how to set up the IR camera for the nondestructive testing are described in detail. Also, its utilization and non-destructive testing(NDT) diagnosis are reviewed. By performing the periodic non-touched WDT through the estimation of thermal patterns related with the temperature for the surface targeted, IRT can be applied to the early prevention of the device failure. For the diagnosis utilization, thermal imaging patterns obtained from IRT for heated blocks with internal defects were estimated through the lion-destructive method and discussed the way of IRT estimation from the analysis of characteristics between material defects and thermal imaging patterns.

• Polymer(Korea)
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• v.29 no.5
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• pp.508-517
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• 2005

The thermal degradation behavior and reliability analysis were investigated using dynamic thermogravimetric analysis (TGA) and accelerated degradation test (ADT) to characterize the dynamic parameters related to thermal degradation of plastic meterials for household electric appliances. In addition, the weathering of the plastic were performed by ADT using Xenon uc, and the color difference of the samples after ADT were measured with Color Eye 3010 specoophotometer. he activation energy for thermal degradation of the samples increased with increasing the rate of weight loss. The Kim-Park method was found to be more effective analysis in describing thermal degradation of plastic meterials. Plastic materials were very sensitive to ultra-violet rays in faster degradation.

• Proceedings of the Korean Society of Disaster Information Conference
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• 2022.10a
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• pp.167-168
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• 2022

본 논문에서는 접지계통에 사용되는 접속계수에 대한 열화특성 분석을 기술한다. 그 접지 시스템의 연결 방법은 IEC 표준에 명시되어 있습니다. 연결부의 열화 특성을 분석하기 위해 인자, 연결 인자를 소금물과 지하에 묻었을 때 열화 시험을 수행하였다. 테스트 연결 계수 C형 슬리브, 클램프 및 발열 용접이 있었습니다. 그 결과, 접속 인자의 대부분이 부식되었고, 전기적 요인이 발생하였다. 저항은 악화된 후에 감소했다. 분석 결과는 접지 시스템의 안전성을 확립하는 데 사용될 수 있다

• 전기의세계
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• v.38 no.11
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• pp.34-47
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• 1989

본고에서는 OF케이블의 gas분석에 관한 언급을 제외하고는 주로 CV케이블의 전기적 특성면에서의 절연열화 진단에 관하여 가장 실용화에 접근한 시험법과 측정결과를 개략적으로 기술하였다. 그러나 소개하지 못한 연구시험중에 있는 신기술도 많이 있다. 다만, 이 여러가지 시험법과 이론이 증명하듯이 최근 전력 케이블의 열화진단 기술을 확립하려는 많은 노력이 경주되고 있다는 것이다. 앞으로 머지않아 이 결과들이 정리되어 최적의 케이블 진단기술이 확립될 것이며 이에따라 전력케이블의 절연파괴 사고를 미연에 방지하므로써 전력공합신뢰도 향상에 이바지 하게 될것으로 확신한다.

• Proceedings of the KIEE Conference
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• 2008.04b
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• pp.214-216
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• 2008

회전기 고정자권선 절연물은 전기적, 기계적, 열적, 환경적 열화요인이 단독 또는 복합적으로 작용하여 열화된다. 본 논문에서는 실제 산업현장에서 운영중인 고전압 전동기의 운영환경을 조사하여 건조환경에서 운영중인 전동기와 다습환경에서 운영중인 전동기에 대하여 절연진단시험을 실시하고 각 시험에서 도출된 절연진단인자를 비교하여 환경적 열화요인이 우세한 운영환경에 따른 절연물의 특성변화를 분석하였다.