• 한국해양공학회지
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• 제6권1호
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• pp.52-61
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• 1992

The steady laminar mixed convection from vertically misaligned, isothermal plastes has been studied by numerical procedure. The governing equations are solved by the finite difference method using successive using successive over relaxation scheme at Re=100-800, $Gr=10^3-10^6$, Pr=0.71 and dimensionless plate spacings b/L=0.1-1.0. The plume interaction caused by the thermal interference of twoplates is observed. As Reynolds numbers increase, the optimum plate spacings are moved to narrow spacings at the same Grashof number and as Grashof numbers increase, to wide spacings at the same Reynolds number.

• 오토저널
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• 제15권3호
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• pp.68-74
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• 1993

The mixed convection heat transfer has been studied numerically for misaligned and parrallel arrays of two flat plates at 100.leg.Re.leg.700, 0.1.leg.B.leg.1.0, 0.2.leg.leg.PHI.$_{R}$.leg.1Gr=10$^{4}$ and Pr=0.71. For misaligned plates and parallel plates, the optimum plate spacings move to the narrow spacing as Reynolds number and .PHI.$_{R}$ increase and can be expressed by the correlation equations at Gr=10$^{4}$. The optimum plate spacings for parallel plates sharply move to the narrow spacing compared with misaligned plates. The maximum mean Nusselt number of parallel plates shows higher value than that of misaligned plates and can be expressed by the correlation equations at Gr=10$^{4}$.EX>.

• 한국대기환경학회지
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• 제12권3호
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• pp.231-241
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• 1996

The effect of radiation and buoyancy on the thermophoresis phenomenon owing to the presence of highly absorbing, emitting particles (such as soot or pulverized coal) suspended in a two phase flow system was investigated numerically for a turbulent mixed convection flow. The analysis of conservation equations for a gas-particle flow system was performed on the basis of a two-fluid model from a continuum Eulerian viewpoint. The modified van Driest and Cebeci mixing length turbulence model was adopted in the anaylsis of turbulent flow. In addition, the P-1 approximation was used to evaluate the radiation heat transfer. As expected from the particle concentration and drift velocity distribution, the cumulative collection efficiency E (x) becomes larger when the buoyancy effect increases (i.e. higher Grashof number), while smaller as the radiation effect increases (i.e. higher optical thickness).

• 대한기계학회논문집
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• 제14권6호
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• pp.1645-1651
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• 1990

본 연구에서는 두 개의 수직 등온 평판이 평행하게 배열된 경우의 혼합대류 열전달에 대하여 무차원 평판 간격, b/l와 Grashof수, 레이놀즈수를 변수로 유한차분 법을 사용 수치해석하고, 두평판사잉의 간섭현상과 열전달을 최대로 하는 최적 평판간 격을 구하였다.

• Communications for Statistical Applications and Methods
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• 제27권3호
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• pp.301-311
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• 2020

Schwarz's Bayesian information criterion (BIC) is one of the most popular criteria for model selection, that was derived under the assumption of independent and identical distribution. For correlated data in longitudinal studies, Jones (Statistics in Medicine, 30, 3050-3056, 2011) modified the BIC to select the best linear mixed effects model based on the effective sample size where the number of parameters in covariance structure was not considered. In this paper, we propose an extended Jones' modified BIC by considering covariance parameters. We conducted simulation studies under a variety of parameter configurations for linear mixed effects models. Our simulation study indicates that our proposed BIC performs better in model selection than Schwarz's BIC and Jones' modified BIC do in most scenarios. We also illustrate an example of smoking data using a longitudinal cohort of cancer patients.

• Journal of applied mathematics & informatics
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• 제5권1호
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• pp.73-90
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• 1998

In this paper we introduce and study a number of new classes of quasi variational inequalities. using essentially the projection technique and its variant forms we prove that the gen-eralized set-valued mixed quasivariational inequalities are equivalent to the fixed point problem and the Wiener-Hopf equations(normal maps). This equivalence enables us to suggest a number of iterative algorithms solving the generalized variational inequalities. As a special case of the generalized set-valued mixed quasi variational in-equalities we obtain a class of quasi variational inequalities studied by Siddiqi Husain and Kazmi [35] but there are several inaccuracies in their formulation of the problem the statement and the proofs of the problem the statement and the proofs of their results. We have removed these inaccuracies. The correct formulation of thir results can be obtained as special cases from our main results.

• Nuclear Engineering and Technology
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• 제49권8호
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• pp.1645-1653
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• 2017

This investigation explores the thermally stratified stretchable flow of an Oldroyd-B material bounded by a linear stretched surface. Heat transfer characteristics are addressed through thermal stratification and heat generation/absorption. Formulation is arranged for mixed convection. Application of suitable transformations provides ordinary differential systems through partial differential systems. The homotopy concept is adopted for the solution of nonlinear differential systems. The influence of several arising variables on velocity and temperature is addressed. Besides this, the rate of heat transfer is calculated and presented in tabular form. It is noticed that velocity and Nusselt number increase when the thermal buoyancy parameter is enhanced. Moreover, temperature is found to decrease for larger values of Prandtl number and heat absorption parameter. Comparative analysis for limiting study is performed and excellent agreement is found.

• 한국생산제조학회지
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• 제23권6호
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• pp.602-608
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• 2014

Mixed-model production lines are often used in manufacturing systems. In production lines, different product types are simultaneously manufactured by processing small batches. This paper describes a new welding assembly technology involving the development of experimental models for a mixed-model production line in an automobile company. Due to the extensive number of models, the design of a welding assembly system is complicated. Performance evaluation is an important phase in the design of welding assembly lines in a mixed-model production environment. In this study, a new welding assembly technology for a mixed-model production method was used to weld the package tray and dash panel of a vehicle.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2021년도 봄 학술논문 발표대회
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• pp.327-328
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• 2021

In the manufacturing process of ready-mixed concrete, quantity management directly affects the workability and strength of concrete. Therefore, water quantity is the most important management factor for water quality control of ready-mixed concrete. It can be said that the number of unit water in the mix design, the water quantity due to the surface water contained in the aggregate used, and the water quantity taking into account the concentration of sludge contained in the recycling water when using the recycling water are factors that affect the quantity management of ready-mixed concrete. In this study, as a stable quality control method of ready-mixed concrete, a quantity management method by aggregate surface water and a sludge concentration management method according to the use of recycling water were proposed. Thus, we tried to suggest an efficient quantity management method for stabilizing the quality of ready-mixed concrete.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2005년도 창립60주년 기념 추계 학술대회
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• pp.24.1-24.1
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• 2005