• 산업경영시스템학회지
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• 제37권4호
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• pp.116-125
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• 2014

In this paper, we investigate an inventory and production system in a three-layer supply chain system involving a single supplier, single manufacturer and multiple retailers. Earlier study in this type of supply chain only consider a single raw material in order to produce single item, but we consider raw materials in order to produce multiple items. It is assumed that the cycle time at each stage is an integer multiple of the adjacent downstream stage. We develop an iterative solution procedure to find the order quantity for the multiple items and raw materials that minimizes the supply chain-wide total cost per unit time of the supplier and manufacturer's raw materials ordering and holding, setup and finished items holding, the retailer's ordering and inventory holding. Numerical examples are presented to show that the proposed heuristic gives good performance.

• 한국자기학회:학술대회 개요집
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• 한국자기학회 2000년도 International Symposium on Magnetics The 2000 Fall Conference
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• pp.461-461
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• 2000

We have investigated electronic structuresof antiferromagnetic YBaCo_2O_5 using the local spin-density approximation (LSDA) + U method. The charge and orbital ordered insulating ground state is correctly obtained with the strong on-site Coulomb interaction. Co^{2+} and Co^{3+} ions are found to be in the high spin (HS) and intermediate spin (IS) state, respectively. The tetragonal to orthorhombic structural transition is responsible for the ordering phenomena and the spin states of Co ions. The large contribution of the orbital moment to the total magnetic moment indicates that the effect of the spin-orbit coupling is very important in YBaCo_2O_5.

• International Journal of Reliability and Applications
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• 제13권1호
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• pp.49-56
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• 2012

Using total time on test transform (TTT), a new approach is taken for testing exponentiality versus the unknown age, exponential better than equilibrium life in convex ordering (EBELC). Selected critical values are tabulated for sample size n =2(2)50 and powers of the test are estimated for some commonly used distributions in reliability. Finally real example is presented to illustrate the theoretical results.

• 산업경영시스템학회지
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• 제31권2호
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• pp.43-50
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• 2008

In this paper we suggest the methods that compute the total inventory cost based on EOQ and the total inventory cost based on OMMIP. The total inventory cost consists of purchasing cost, ordering cost, inventory holding cost, stockout cost and so on. This papers also proposes the method that decides optimum order quantity as the order amount to minimize the total inventory cost with comparison of EOQ total inventory cost and OMMIP total inventory cost according to inventory holding cost as a fraction of unit cost.

• 대한안전경영과학회지
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• 제12권4호
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• pp.153-160
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• 2010

In this paper, effects of information sharing in multi-level supply chain management have been studied through simulation. The simulation model consists of a manufacturing company as a center, three suppliers, two logistic centers, and three different retail supply lines of each logistics centers. The mathematical model and the simulation were developed when real-time information sharing occurs and does not occur in supply chain under the assumption that each company applies (s, S) inventory policies. In addition, this paper analyzed the effects of the change of variables related to total costs, which compose of total ordering cost, total transportation cost, total carrying cost and shortage cost that are caused by the change of demand of three different patterns with the way of information sharing.

• 대한산업공학회지
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• 제11권1호
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• pp.41-49
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• 1985

This paper studies the two supplier inventory system in which order-level inventory policy with constant leadtimes is adopted. An optimal ordering policy to achieve the expected minimum total inventory cost is found by utilizing the concepts of the equivalence relation. Sensitivity analysis of the system parameters, the replenishment cost and the unit price, is done through a numerical example.

• 산업경영시스템학회지
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• 제13권22호
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• pp.35-42
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• 1990

This paper deals with a single machine scheduling problem with a quadratic penalty function of completion times. The objective is to find a optimal sequence which minimizes the total penalty. A new type of node elimination procedure and precedence relation is developed that determines the ordering between adjacent jobs and is incorporated into a branch and bound algorithm. In addition, modified penalty function is considered and numerical examples are provided to test the effectiveness of the optimum algorithm.

• 대한산업공학회지
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• 제19권1호
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• pp.73-77
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• 1993

This paper considers an Economic Order Quantity Model under random life cycle. It is assumed that the life cycle of the product is unknown; a random variable. Three cost parameters are considered; ordering cost, inventory carrying cost and salvage cost. Expected total cost is the optimization criterion. We show that the optimal cycle length is unique and finite, and present a simple line search method to find an optimal cycle length.

• 한국경영과학회:학술대회논문집
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• 대한산업공학회/한국경영과학회 1990년도 춘계공동학술대회논문집; 한국과학기술원; 28 Apr. 1990
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• pp.222-244
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• 1990

A multi-echelon structure of manufacturing and distribution system in considered, where the raw materials are transformed into a finished good through a number to manufacturing echelons and it is distributed to the lower echelons(retailers, or customers). The raw material, work-in-process, finished good inventory and the distribution costs are unified into one model. The objective is to determine the ordering policy of raw materials, manufacturing lot size, the number of sub-batch and the distribution policy of the finished good which minimize the annual total system cost. A computer program for a heuristic search technique is developed, by which a numerical example is examined.

• 한국지능시스템학회논문지
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• 제5권1호
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• pp.21-24
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• 1995

Fuzzy inference method is introduced to order totally a partiallyordered system. When there there are more than one order indices and fuzzy order rules, the proposed method provides one order index by mixing them.