• Communications of the Korean Mathematical Society
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• v.34 no.1
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• pp.239-251
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• 2019

In this paper we introduce a new formulation of symmetric homogeneous bivariate means that depends on the variation of a given continuous strictly increasing function on (0, ${\infty}$). It turns out that this class of means includes a lot of known bivariate means among them the arithmetic mean, the harmonic mean, the geometric mean, the logarithmic mean as well as the first and second Seiffert means. Using this new formulation we introduce a lot of new bivariate means and derive some mean-inequalities.

• IE interfaces
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• v.17 no.1
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• pp.78-83
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• 2004

We consider the sensitivity of average inventory cost rate when true values of the parameters in the EOQ model are unknown over known ranges. In particular, in the case that the valid range on the true economic lot size are known, we provide a formula for estimating the lot size under minimax criterion. Moreover, to estimate the valid range, we apply the propagation of errors technique. Then, we present a scheme to find a (valid) lot size, based on the estimated range of the true lot size from the propagation of errors technique.

• IE interfaces
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• v.10 no.1
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• pp.47-55
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• 1997

This paper deals with an assembly process of the TFT glasses and the color filters in LCD manufacturing. Two specific problems are presented and solved. One is a matching problem to find the best matches between a set of TFT glasses and a set of color filters, which result in the maximum number of good LCD assemblies. A simple mathematical model is constructed for this problem and an optimal solution can be obtained using an existing algorithm. The other is a main problem that requires a determination of an economic lot size of the color filters which are going to be assembled with a given set of TFT glasses. A Bayesian dynamic forecasting model is developed to predict the defective patterns of color filters. Based on the predicted defective rate of color filters, the minimum lot size of the color filters can be determined to minimize the probability of losing good TFT glasses and color filters.

• Journal of the Korean Operations Research and Management Science Society
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• v.28 no.4
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• pp.31-37
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• 2003

This paper deals with a stowage plan for plates in a warehouse. This plan includes how to place each plate and how to sequence outgoing lots for picking. A group of plates in an outgoing lot should be loaded in the same outgoing pallet and between two elates in the same lot, no plate from other than the lot should be placed. Since the approach to the plates is only from above, when the plates in the different lots are placed mixed in a warehouse, we have to temporarily move many of plates in some other place to let a plate in the lot for which loading is under way go out. Our purpose is to minimize those temporary moves. We analyze the computational complexity of several problems arising in the stowage plan of a plate warehouse.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2003.05a
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• pp.1028-1034
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• 2003

We consider the sensitivity of average inventory cost rate when true values of the parameters In the EOQ model are unknown over known ranges. In particular, In the case that the valid range on the true economic lot size are known. we provide a formula for estimating the lot size under minimax criterion. Moreover, to estimate the valid range, we apply the propagation of errors technique. Then, we present a scheme to find a (valid) lot size. based on the estimated range of the true lot size from the propagation or errors technique.

• Journal of Korean Society for Quality Management
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• v.24 no.3
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• pp.77-93
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• 1996

This paper is concerned with the International Standard ISO 2859-1 (1989), Sampling Plans Indexed by Acceptable Quality Level (AQL) for Lot-by-Lot Inspection, his standard is AQL type sampling scheme, and incorporates switching rules to move among normal, tightened, and reduced inspections. Sample size code letters and inspection levels of ISO 2859-1 are the same as those of other attributes standards MIL-STD-105D, ANSI Z1.4, and KS A 3109. But ISO 2859-1 has more simple switching rules than KS A 3109 has. The sampling procedures of the ISO 2859-1 are matched to the variables international standard ISO 3951 to enable us to move between them. Composite OC and ASN curves are given for AQL 2.5% and code letter F.

• Journal of the Korea Institute of Building Construction
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• v.4 no.2
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• pp.73-80
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• 2004

The purpose of this study was to look up the proper inventory management system in construction industry. it is important for construction company to improve competitiveness and to reduce construction cost. Lot-sizing techniques were applied to rebar procurement in apartment project. The results of this study were as follows; the method of Groff's marginal cost showed the best performance of other techniques and the method of Norman showed a similar result.

• Journal of Korean Institute of Industrial Engineers
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• v.32 no.2
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• pp.98-103
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• 2006

In this research, the single machine capacitated lot-sizing and scheduling problem with sequence- dependent setup costs and setup times (CLSPSD) is considered. This problem is the extension of capacitated lot-sizing and scheduling problem (CLSP) with an additional assumption on sequence-dependent setup costs and setup times. The objective of the problem is minimizing the sum of production costs, inventory holding costs and setup costs satisfying customers' demands. It is known that the CLSPSD is NP-hard. In this paper, the MIP formulation is presented. To handle the problem more efficiently, a conceptual model is suggested, and one of the well-known meta-heuristics, the simulated annealing approach is applied. To illustrate the performance of this approach, various instances are tested and the results of this algorithm are compared with those of the CLPEX. Computational results show that this approach generates optimal or nearly optimal solutions.

• 한국전산유체공학회:학술대회논문집
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• 2011.05a
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• pp.477-482
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• 2011

In the present study, the diffusion process of hydrogen leaking from a FCV (Fuel Cell Vehicle) in an underground parking lot was analyzed by numerical simulations in order to assess the risk of a leakage accident. The temporal and spatial changes of the hydrogen concentration as well as the flammable region in the parking lot were predicted numerically. The effects of the leakage flow rate and an additional ventilation fan were investigated to evaluate the ventilation performance in the parking lot to relieve the accumulation of the leaked hydrogen gas. The present numerical analysis can provide useful information such as the distribution of the leaked hydrogen concentration for safety of various hydrogen applications.

• Journal of the Korean Institute of Rural Architecture
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• v.5 no.2
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• pp.10-19
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• 2003

The purpose of this study was to analyze the formation and change of road-block-lot of the old inner city in cheongju The result of this study are as follows; (I)Among others a system roads of in around the old castle in cheongju city is most of feature north and south direction of road. Lot system is organic relations of north and south direction of road. Therefore, urban tissue in around the old castle in cheongju city is established order road system keep on the change of expansion urban tissue. (2) Block type classified into non-division, 2division and over 3division. (3) The square block remains mostly in Cheongju old castle, two-division block was around south of castle. And block of the grid-form street system divided into over 3 division. Through the guideline about characteristic of block type, residential area should be developed as a characteristics area in the urban area.