• Nuclear Engineering and Technology
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• v.49 no.8
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• pp.1636-1644
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• 2017

The main purpose of this article is to describe the magnetohydrodynamic stagnation point flow of Walter-B nanofluid over a stretching sheet. The phenomena of heat and mass transfer are based on the involvement of thermal radiation and chemical reaction. Characteristics of Newtonian heating are given special attention. The Brownian motion and thermophoresis models are introduced in the temperature and concentration expressions. Appropriate variables are implemented for the transformation of partial differential frameworks into sets of ordinary differential equations. Plots for velocity, temperature, and nanoparticle concentration are displayed and analyzed for governing parameters. The skin friction coefficient and local Nusselt and Sherwood numbers are studied using numerical values. The temperature and heat transfer rate are enhanced within the frame of the thermal conjugate parameter.

• Journal of the Korean housing association
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• v.4 no.2
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• pp.55-62
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• 1993

지금까지 연구해 온 바닥난방이 인체에 미치는 생리적, 심리적 영향에 관한 실험결과를 종합하여(건강한 여자를 피험자로 한 경우) 바닥난방의 Optimum Thermal Environmental Conditions 를 검토할 때는 다음의 조건을 만족시켜야 한다. (1) 저온 화상의 위험성을 고려하여 접촉부위의 피부온도가 $40^{\circ}C$를 넘지 않을 것. (2) 생리적 영향으로써 평균 피부온도가 $33{\;}-{\;}34^{\circ}C$의 범위일 것. (3) 심리적 영향으로써 온냉감 평가가 열적중성(slightly cool - slightly warm)으로 평가하고, 쾌적감 평가가 쾌적한 것으로 평가할 것. (4) 바닥온도에 대한 만족감 평가가 높을 것. (5) 흑구온도는 직접바닥에 앉는 자세에서는 $17^{\circ}C$ 이상, 의자에 앉는 자세에서는 $19^{\circ}C$ 이상일 것. 이상의 조건을 만족시키는 범위가 바닥난방의 Optimum Thermal Environmental Zone (Fig.7) 이라고 생각된다.

• Structural Engineering and Mechanics
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• v.24 no.6
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• pp.699-707
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• 2006

In the paper, a direct method of solution of the Navier equation is presented. An orthotropic thick hollow cylinder under a one-dimensional steady-state temperature distribution and a uniform magnetic field with general types of thermal and mechanical boundary conditions is considered. The Navier equation in terms of displacement is derived and solved analytically by the direct method, and magnetothermoelastic responses and perturbation of the magnetic field vector in the orthotropic thick hollow cylinder is described. The present method is suitable for orthotropic thick hollow cylinders placed in an axial magnetic field with arbitrary thermal and mechanical boundary conditions. Finally, numerical examples are carried out and discussed.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1213-1218
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• 2004

Film growth rate of InP and GaAs using TMI, TMG, TBA and TBP is numerically predicted and compared to the experimental results. Obtained results show that the film growth rate is very sensitive to the thermal condition in the reactor. To obtain exact thermal boundary conditions at the reactor walls, we analyzed the gas flow and heat transfer in the reactor including outer tube as well as the inner reactor parts using a full three-dimensional model. The results indicate that the exact thermal boundary conditions are important to get precise film growth rate prediction.

• Proceedings of the Korean Society Of Semiconductor Equipment Technology
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• 2003.12a
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• pp.192-199
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• 2003

Film growth of InP and GaAs using TMIn, TMGa, TBAs and TBP is numerically predicted and compared to the experimental results. To obtain exact thermal boundary conditions at the reactor walls, the gas flow and heat transfer are analyzed for full three-dimensional reactor including outer tube as well as the inner reactor parts. The results indicate that the exact thermal boundary conditions are important to get precise film growth rate prediction since film deposition is mainly controlled by the temperature dependent diffusion. The results also show that thermal diffusion plays an important role in the upstream region.

• Steel and Composite Structures
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• v.12 no.2
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• pp.129-147
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• 2012

In this paper, the thermal buckling analysis of rectangular composite laminated plates is investigated using the Differential Quadrature (DQ) method. The composite plate is subjected to a uniform temperature distribution and arbitrary boundary conditions. The analysis takes place in two stages. First, pre-buckling forces due to a temperature rise are determined by using a membrane solution. In the second stage, the critical temperature is predicted based on the first-order shear deformation theory. To verify the accuracy of the method, several case studies were used and the numerical results were compared with those of other published literatures. Moreover, the effects of several parameters such as aspect ratio, fiber orientation, modulus ratio, and various boundary conditions on the critical temperature were examined. The results confirm the efficiency and accuracy of the DQ method in dealing with this class of engineering problems.

• Journal of the Korean Society for Precision Engineering
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• v.25 no.1
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• pp.92-98
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• 2008

The flame image observation and analysis has been investigated for combustion monitoring and management of the pulverized coal firing for thermal power plant, especially for lower nitrogen oxide generation and safer operation. We aimed at obtaining the relationship between burner flame image information and emissions of nitrogen oxide and unburned carbon in furnace utilizing the flame image processing methods, by which we quantitatively determine the conditions of combustion on the individual homers. Its feasibility test was undertaken with Samchonpo thermal power plant #4 unit which has 24 burners, through which the system was observed to be effective for evaluating the combustion conditions and continuous monitoring to prevent future loss of ignition.

• 한국방재학회:학술대회논문집
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• 2008.02a
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• pp.653-655
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• 2008

In order to examine the influences by the extreme weather changes on the human physical conditions, we need to undertake human biometeorology research such as the assesment on the extreme heat's influences on human health. Most of the preceding studied have been found to be focused on the influences by extreme heat on the human body, they used statistics on the daily mortality. But thismethod estimate an indirectly influences by extreme heat on the human body. So, to be able to predict the possible directly influences by the extreme heat on the physical conditions. We measure thermal stress by extreme heat.

• Transactions of the Korean Society of Automotive Engineers
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• v.14 no.5
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• pp.9-16
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• 2006

The present study is to simulate coolant flow in IC engine cooling passages under subcooled nucleate boiling conditions and investigate thermal stress analysis of the solid part. To consider nucleate boiling heat transfer effect, Chen's empirical formula is used through user subroutine programing in CFD code and then nucleate boiling model is compared with Robinson's experimental results, which shows reasonable agreement. This Chen's nucleate boiling model is applied to single cylinder IC engine model and we do cylinder liner thermal stress analysis using commercial FEM code.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.17 no.3
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• pp.1-12
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• 2021

In this study, the effects of various operational conditions for floor radiant heating system were researched by experiments. Hot water supply set temperature, indoor air set temperature and supply water flowrate were considered as operational conditions. The control method for this system is On-Off control of automatic thermostatic valve. The purpose of this study is to evaluate indoor thermal control characteristics and energy performance, respectively. As a result, if lower supply water temperature is applied, the supply and return temperature difference is reduced and energy consumption of heat supply is also reduced.