• Proceedings of the KIEE Conference
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• 2009.07a
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• pp.391_392
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• 2009

DTS 시스템에서 측정하는 분포온도 데이터는 지중케이블의 상태 감시에 유용하게 사용될 수 있다. 본 연구에서는 분포온도센서로부터 획득되는 온도 데이터를 기반으로 지중케이블의 상태 감시 및 실시간 허용용량을 산정할 수 있는 모니터링 시스템을 개발하였다. 본 시스템은 사례 기반의 모니터링 GUI를 구축하는 것을 지양하고, 임의의 지중케이블 시스템에 적용이 가능한 GUI 설정 기능을 갖추었으며, 케이블의 동적허용용량 산정 모듈, 분포온도 해석 모듈, 경보 모듈, 설정 모듈, 이력조회 모듈 등으로 구성된다.

• Proceedings of the Korea Concrete Institute Conference
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• 2009.05a
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• pp.267-268
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• 2009

s manufacturing the Precast Concrete simulation structure, we generally investigated the temperature characteristics of the concrete according to diversity of the cement and heat curing condition respectively.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.5
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• pp.1665-1673
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• 1991

본 연구에서는 운전이력이 다른 보일러 과열기 및 재열기에서 수취한 Cr-Mo강 증기관을 대상으로 이 SP 시험법을 도입하여 SP시험에 의한 재질열화의 평가 가능성을 연구 검토하였다.

• Journal of the Korea Concrete Institute
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• v.21 no.4
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• pp.481-488
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• 2009

It has been reported that the magnitude and the development rate of autogenous shrinkage of cement paste, mortar and concrete were affected by history and magnitude of inner temperature at an early age. But it was not enough to explain the relation between hydration heat and autogenous shrinkage at an early age, because there was no certain analysis on histories of hydration heat and autogenous shrinkage in previous studies. In our prior study, to understand the relationship between hydration heat and autogenous shrinkage of concrete at an early age, the analysis method for histories of hydration heat and autogenous shrinkage was suggested. Based on this method, early age properties of hydration heat and autogenous shrinkage of high strength concrete with different sizes and hydration retardation were investigated in this study. As a result of the study, properties of hydration temperature and autogenous shrinkage were different according to specimen size and hydration retardation. However, there was a close relationship between hydration temperature and autogenous shrinkage at an early age, especially between HHV and ASV as linear slopes of the sections where hydration temperature and autogenous shrinkage increase rapidly; the higher HHV, the higher ASV and the greater ultimate autogenous shrinkage. And it was found that, among the setting time, bend point and temperature increasing point, they were close relationship each other on cement hydration process.

• Korean Journal of Crystallography
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• v.12 no.3
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• pp.157-161
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• 2001

The observe relaxation phenomena and freezing behavior in Pb(Mg/sub ⅓/Nb/sub ⅔/O₃, relaxor ferroelectrics, weak electric-field properties as well as strong electric-field properties were investigated. The temperature dependence of the dielectric properties obtained using the low electric-field of 1 V/w was investigated. The dielectric properties obtained from the slope of the dielectric hysteresis loop and the temperature dependence of the pyroelectric properties were also investigated. When fitting all the experimental data with the Vogel-Filcher relation, a close agreement between the experimental data and equation was observed. The freezing temperature could be consistently calculated by the various methods.

• Proceedings of the Acoustical Society of Korea Conference
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• 1998.06d
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• pp.29-34
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• 1998

Egg white의 gel화에 따른 음속과 흡수의 변화가 60와 75$^{\circ}C$에서 크게 나타난 것이 egg white의 어느 단백질 성분에 의한 것인가를 조사하기 위해 egg white의 주요한 단백질 성분인 obalbumin, conalbumin, ovomucoid protein에 대해 gel화에 따른 음속 및 흡수의 변화를 온도 10-95$^{\circ}C$의 범위에서 초음파pulse법을 사용하여 측정하였다. Ovalbumin는 7$0^{\circ}C$, conalbumin는 5$0^{\circ}C$에서 gel화가 시작되었고 ovomucoid는 측정온도범위내에서는 gel화가 진행되지 않았다. Gel화하는 이상의 온도에서 음속과 흡수에 대하여 aging측정을 행하여 gel화에 의한 dam속과 흡수의 변화를 관측하였다. 그 결과 conalbumin는 5$0^{\circ}C$, ovalbumin는 75$^{\circ}C$에서 음속과 흡수의변화가 많이 일어났다. Egg white의 60와 75$^{\circ}C$의 gel화에 의한 음속과 흡수의 큰 변화는 각각 conalbumin과 ovalbumin에 의한 것임을 알았고 Conalbumin과 ovalbumin는 aging 온도를 parameter로하여 이력현상이 관측되었다.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.11a
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• pp.131-132
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• 2021

According to the domestic specification, the curing of the specimen for strength management used to determine the time of the mold deformity of the structure concrete in early spring and early autumn is cured in the field structure condition. However, when the seal curing is performed in the field, the temperature of the specimen is very low compared to the temperature of the actual structure, so the strength of the structure concrete predicted based on the strength of the specimen is much undervalued than the actual one, which causes the mold to be deformed. Therefore, this study analyzed the temperature history and compressive strength characteristics of the specimen for strength management through other sealing curing at 5℃ and concrete of the actual structure, and presented the most suitable curing method.

• The Journal of the Acoustical Society of Korea
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• v.9 no.6
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• pp.74-80
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• 1990

천연 단백질인 egg white의 gel화의 과정을 초음파 측정에 의하여 연구하였다. Egg white는 6 0℃ 이상의 어떤 온도에서 aging 측정을 하면 gel화의 진행에 따라 흡수는 증가, 음속은 감소하였다. Egg white의 gel 화는 60℃와 75℃에서 크게 진행하였고, egg white gel의 비가역성을 반영해서 음속과 흡수 모두 이력현상이 관측되었다.

• Journal of Energy Engineering
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• v.8 no.4
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• pp.605-611
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• 1999

Conventional methods for assessing remaining life of critical high temperature components in fossil power plants rely on nondestructive inspection practices and accompanying life analysis based on fracture mechanics By using these conventional methods. It has been difficult to perform uninterrupted in-service inspection for life prediction. Thus, efforts have been made for developing on-line remaining life monitoring systems employing information on the shape of structures, operating variables and material properties. In thus study, a software for on-line life monitoring system which performs real-time life evaluation of a high temperature system headers was developed. The software is capable of evaluating creep and fatigue life usage from the real-time stress data calculated by using temperatures/stress transfer Green functions derived in advance for the specific headers. The major benefits of the developed software life in determining future operating schedule, inspection interval, and replacement plan by monitoring real-time life usage based on prior operating history.

• Fire Science and Engineering
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• v.26 no.6
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• pp.45-50
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• 2012

The spalling causes the sever reduction of the cross sectional area with the exposure of the reinforcing steel, which originates a problem in the structural behaviour. By coating surface of high strength concrete with fireproof mortar, the high strength concrete is protected from the spalling in fire and the method to constrain the temperature increase of steel bar within the concrete. The purpose of this study is to investigate the temperature history properties of lightweight mortar using perlite and polypropylene fiber for fire protection covering material. For this purpose, selected test variables were the contents and length of polypropylene fiber. As a result of this study, it has been found that addition of polypropylene fiber to mortar modifies its pore structure and this causes the internal temperature to rise. And it has been found that a new lightweight mortar can be used in the fire protection covering material.