• Journal of Korean Society of Industrial and Systems Engineering
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• v.40 no.4
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• pp.29-37
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• 2017

This papers focuses on remanufacturing processes in a closed loop supply chain. The remanufacturing processes is considered as one of the effective strategies for enterprises' sustainability. For this reason, a lot of companies have attempted to apply remanufacturing related methods to their manufacturing processes. While many research studies focused on the return rate for remanufacturing parts as a control parameter, the relationship with demand certainties has been studied less comparatively. This paper considers a closed loop supply chain environment with remanufacturing processes, where highly fluctuating demands are embedded. While other research studies capture uncertainties using probability theories, highly fluctuating demands are modeled using a fuzzy logic based ambiguity based modeling framework. The previous studies on the remanufacturing have been limited in solving the actual supply chain management situation and issues by analyzing the various situations and variables constituting the supply chain model in a linear relationship. In order to overcome these limitations, this papers considers that the relationship between price and demand is nonlinear. In order to interpret the relationship between demand and price, a new price elasticity of demand is modeled using a fuzzy based nonlinear function and analyzed. This papers contributes to setup and to provide an effective price strategy reflecting highly demand uncertainties in the closed loop supply chain management with remanufacturing processes. Also, this papers present various procedures and analytical methods for constructing accurate parameter and membership functions that deal with extended uncertainty through fuzzy logic system based modeling rather than existing probability distribution based uncertainty modeling.

• Journal of the Korean Society for Aeronautical & Space Sciences
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• v.44 no.1
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• pp.88-97
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• 2016

A closed loop thermal control system simulates space thermal environment to verify the satellites' functionality in extremely cold/hot temperature. It is composed of a cryogenic blower, thermal shroud, heater, cryogenic valves. This paper presents an overview of closed loop thermal control system's design parameter and test results for control parameter. A capacity of blower is calculated through energy balance equation and an advantage/disadvantage for a shroud material and a type was analysed. The thermal control system is controlled by a constant density of fluid in the system. A requested performance of closed loop thermal control system was verified by measuring a homogeneity and stability of shroud through control parameter such as density and RPM of blower.

• Bulletin of the Korean Chemical Society
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• v.24 no.6
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• pp.859-863
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• 2003

We report on the theoretical positron affinities of closed-shell atomic anions. The second-order many-body perturbation theory is applied taking the positron-electron interaction as a perturbation. The corrections for the complete basis set effects to the second order affinity are calculated based on the variational and nonvariational energy functionals of explicitly correlated geminals. It is shown that the explicitly correlated methods accelerate the convergence of the expansion significantly giving the account of the cusp behavior outside the orbital space.

• The Pure and Applied Mathematics
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• v.17 no.2
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• pp.175-183
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• 2010

Using Darbo's fixed point theorem, we establish the existence of monotone solutions for a nonlinear quadratic integral equation of Volterra type in the Banach space of real functions defined and continuous on a bounded and closed interval.

• Communications of the Korean Mathematical Society
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• v.25 no.2
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• pp.303-311
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• 2010

Recently, some authors [3, 4, 11, 12, 15] adopted the concept of the so-called generalized R-KKM maps which are used to rewrite known results in the KKM theory. In the present paper, we show that those maps are simply KKM maps on G-convex spaces. Consequently, results on generalized R-KKM maps follow the corresponding previous ones on G-convex spaces.

• Journal of the Korean Statistical Society
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• v.25 no.4
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• pp.545-556
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• 1996

In this paper, we introduce a new concept of partial ordering which permits us to compare pairs of the dependence structures of a new hitting times for POD multivariate vector process of interest as to their degree of POD-ness. We show that POD ordering is closed under convolution, limit in distribution, compound distribution, mixture of a certain type and convex combination. Finally, we present several examples of POD ordering processes.

• Journal of Chest Surgery
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• v.10 no.1
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• pp.140-142
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• 1977

Total of 52 patients having ventricular septal defect were operated on using extracorporeal circulation in the 8 years period between 1969 and 1977. Of these, the very rare and interesting were the cases of ventricular septal defect seen in twin boys. Their defects were Type II and Type III in each which had been closed with Teflon felt patch in one and with primary suture in the other. Their postoperative courses were uneventful without complications of any.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
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• 2003.04a
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• pp.3-8
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• 2003

In this study, using linear and nonlinear deformation theories and by closed-form analysis and finite difference energy methods, respectively, various buckling load factors are obtained for stiffened laminated composite panel with trapezoidal type stiffeners and various longitudinal length to radius ratios, which are made from Carbon/Epoxy USN 125 prepreg and are simply-supported on four edges under uniaxial compression, and then for them, optimal design analyses are carried out by the nonlinear search optimizer, ADS.

• Bulletin of the Korean Mathematical Society
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• v.40 no.1
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• pp.85-89
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• 2003

Let V be a localizing infinite-dimensional complex Banach space. Let X be a flag manifold of finite flags either of finite codimensional closed linear subspaces of V or of finite dimensional linear subspaces of V. Let E be a holomorphic vector bundle on X with finite rank. Here we prove that E is uniform, i.e. that for any two lines $D_1$ R in the same system of lines on X the vector bundles E$\mid$D and E$\mid$R have the same splitting type.

• 제어로봇시스템학회:학술대회논문집
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• 2000.10a
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• pp.21-21
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• 2000

In this paper, we design the state feedback gain using linear matrix inequality(LMI) to the multiobjective synthesis, in the magnetic bearing system with integral type servo system. The design objectives can be a H$\_$$\infty$/ performance, asymptotic disturbance rejection, time-domain constraints, on the closed-lnp pole location. To the end, we investigated the validity of the designed controller through results of simulation.