• 대기
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• 제18권3호
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• pp.199-206
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• 2008

This study employs a structural time series method in order to model and estimate stochastic trend of surface temperatures of the globe, Northern Hemisphere, and Northeast Asia ($20^{\circ}N{\sim}60^{\circ}N$, $100^{\circ}E{\sim}150^{\circ}E$). For this study the reanalysis data CRUTEM3 (CRU/Hadley Centre gridded land-surface air temperature Version 3) is used. The results show that in these three regions range from $0.268^{\circ}C$ to $0.336^{\circ}C$ in 1997, whereas these vary from $0.423^{\circ}C$ to $0.583^{\circ}C$ in 2007. The annual mean temperature over Northeast Asia has increased by $0.031^{\circ}C$ in 2007 compared to 1997. The climate change in surface temperatures over Northeast Asia is slightly higher than that over the Northern Hemisphere.

• Architectural research
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• 제10권1호
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• pp.1-11
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• 2008

A Steel column with damaged spray-applied fire resistive material (SFRM) may exhibit reduced structural performance due to the effects of elevated temperature during fire events. Thus, the fire load behavior of steel columns with removed or reduced SFRM needs to be examined to predict the structural damage by fire. FEM analyses were performed for the flange thinning removal models in which the SFRM was reduced as a constant strip in thickness at the top flange of the column. The temperature results for all models obtained from the heat transfer analyses were included as an initial condition in the FEM structural analyses. In this study, the results of analysis show that even small remnants of SFRM led to an effective reduction of temperature at any given fire duration, and improved significantly the axial load capacity of a column as compared to the complete removal cases of SFRM.

• 한국기계가공학회지
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• 제11권4호
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• pp.180-184
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• 2012

3-way ball valves have been mostly used for high temperature/high pressure valves using in petrochemical carriers and oil tankers, which requires high quality products with confidentiality and durability. As a larger disaster may be generated by leakage of oil or gas from valves, thus the present research applied a numerical analysis method with thermal-structural coupled field analysis and the performance test. The Max stress by parts was confirmed through thermal-structural coupled field analysis and develop the 3-way ball valve design, which is safe on operating condition. And its performance was verified by carrying out pressure test, leakage test and durability test for the manufactured 3-way ball valves with satisfying it's regulations.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2016년도 춘계 학술논문 발표대회
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• pp.120-121
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• 2016

Recently, the building has been changed into high-rise and long span and this yields a development of high performance structural steels in construction market. According to this effect, the SM 520 and the SM 570 were developed and utilized into steel building industry. However, the study for fire resistance of them were not done actively. In this study, to know and comparative the fire resistance performance of long span beams built up with high strength structural steels an analytical method is going to applied using mechanical and thermal properties at high temperature.

• Steel and Composite Structures
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• 제1권1호
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• pp.111-130
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• 2001

This paper presents an effective, reliable and accurate method for prediction of structural behaviour of steel frames at elevated temperature. The refined plastic hinge method, which has been used successfully in the second-order elasto-plastic analysis of steel frames at ambient conditions, is adopted here to allow for time-independent fire effects. In contrast to the existing rigorous finite element programs, the present method uses the advanced analysis technique that provides a simple and reliable means for practical study of the behaviour of steel frames at elevated temperature by a limiting stress model. The present method is validated against other test and numerical results.

• 한국추진공학회지
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• 제5권3호
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• pp.1-9
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• 2001

잠수함용 재료로 개발된 고강도 구조용강의 충격 시험이 수행되었다. 특히 샤르피 충격시험기를 이용하여 저온에서 구조용 강의 충격특성을 평가하였다. 최소흡수에너지, 최대흡수에너지, 연성 취성 천이온도를 결정하기 위하여 hyperbolic tangent curve fitting법을 이용하였다. 시험결과로부터 샤르피 충격에너지와 횡팽창량 사이의 비례 관계식을 산출하였다. 시험온도 변화에 따른 파단면 특성을 평가하기 위하여 SEM을 이용하여 파단면을 관찰하였다.

• Journal of Magnetics
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• 제3권1호
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• pp.21-30
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• 1998

An artificially modulated magnetic Co/Pd multilayer is one of the promising candidates for high density magneto-optic (MO) recording media, due to large Kerr rotation angle in the wavelength of a blue laser beam. however, since multilayer structure, as well as amorphous structure, is a non-equilibrium state in terms of free energy and MO recording is a kind of thermal recording which is conducted aound Curie temperature (Tc) of the recording media, when the multilayer is used for the MO recording media, changes in the multilayer structure are occurred as the amorphous structure do. Therefore, the assessment of the structural stability in the Co/Pd multilayer is crucially important both for basic research and applications. As the parameter of the structural stability in this research, modulation amplitude and particle size of the Co/Pd multilayer are measured in terms of Ar sputtering pressure and heat treatment temperature. From the results of the research, we find out that the magnetic exchange energy in the structural changes of a magnetic multilayer structure and suggest the operating temperature range for MO recording in the Co/Pd multilayer for the basic research and applications, respectively.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 2004년도 추계 학술발표회 제16권2호
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• pp.585-590
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• 2004

An analytical method is proposed for the analysis of the reinforced concrete flexural beam subjected to high temperature. The analysis procedure for the material properties, in this study, is subdivided into two types; thermal properties for temperature distribution analysis and mechanical properties for structural analysis. Using F.D.M. and segmentation method, the program was made to predict the thermal behavior of RC beams during heating. In previous studies, the structural behavior of fire damaged RC beams was investigated though experiments. Comparing the result by program to the one by experiment, the comparison indicated that the proposed segmentation method for the thermal respose analysis present fairly a good agreement with experiment.

• 한국산학기술학회논문지
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• 제13권8호
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• pp.3352-3357
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• 2012

본 논문은 열매체(Synthetic Heat Transfer Fluid) 보일러의 화재원인을 분석하기 위하여 3차원 자동설계 프로그램인 CATIA를 활용하여 설계하였다. 또한 3차원 유한요소 코드인 ANSYS를 활용하여 설계된 열매체보일러에 대하여 구조해석을 실시하였다. 구조해석을 통하여 열매체보일러의 정상상태와 화재 후의 최대온도(maximum temperature), 최대응력(maximum stress), 최대변형율(maximum strain) 등을 구하였다.

• 한국진공학회지
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• 제7권s1호
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• pp.1-6
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• 1998

The influence of the order-disorder structural transition on the magnetic and mageto-optical, and transport properties of Fe-Al and Co-Al alloy films has been investigated. The disordered states in the alloy films were prepared by vapor quenching deposition on glass substrates cooled by liquid nitrogen. The experimental study of the magento-optical properties of the ordered and disordered Fe-Al and Co-Al alloy films has been carried out in 1.05-5.0 eV energy range at room temperature. The transport properties have been measured in 2-300K temperature range with and without magnetic field of 0.5T. The influence of the order-disorder structural transition on the magnetic and magneto-optical properties was discussed by using the effective medium approximation and the structural defect approach. That on the temperature dependence of the resistivity was analyzed in a framework of the partial localization of the electronic states and the variable range hopping conductivity.