• Journal of the Korea Safety Management & Science
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• v.15 no.1
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• pp.217-229
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• 2013

As customers' demands for diversified small-quantity products have been increased, there have been great efforts for a firm to respond to customers' demands flexibly and minimize the cost of inventory at the same time. To achieve that goal, in SCM perspective, many firms have tried to control the inventory efficiently. We present an mathematical model to determine the near optimal (s, S) policy of the supply chain, composed of multi suppliers, a warehouse and multi retailers. (s, S) policy is to order the quantity up to target inventory level when inventory level falls below the reorder point. But it is difficult to analyze inventory level because it is varied with stochastic demand of customers. To reflect stochastic demand of customers in our model, we do the analyses in the following order. First, the analysis of inventory in retailers is done at the mathematical model that we present. Then, the analysis of demand pattern in a warehouse is performed as the inventory of a warehouse is much effected by retailers' order. After that, the analysis of inventory in a warehouse is followed. Finally, the integrated mathematical model is presented. It is not easy to get the solution of the mathematical model, because it includes many stochastic factors. Thus, we get the solutions after the stochastic demand is approximated, then they are verified by the simulations.

• Journal of the Korea Safety Management & Science
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• v.6 no.3
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• pp.141-152
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• 2004

Supply chains for agricultural commodities with their various constraints such as production lead time, seasonal production, and methods of storage are limited in the extent to which techniques like Just-in-Time (JIT) inventory management can be applied. It is beyond the ability of producers to control harvest time and many agricultural products are perishable so that they can incur exceptional losses in storage if they are not handled correctly. This is a source of additional costs and inefficiency in supply chain management. The purpose of this study is to reduce or eliminate such sources of loss and inefficiency and to identify success factors for the JIT inventory management system where it can be applied for agricultural products. Where JIT techniques can be applied in supply chain management for agricultural products, costs such as transportation, inventory, and storage losses can be reduced with concurrent increases in efficiency. In the paper, some of the problems associated with applying JIT inventory control methods in supply chain management for agricultural commodities will be reported through a series of case studies.

• Proceedings of the Safety Management and Science Conference
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• 2004.05a
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• pp.191-201
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• 2004

Supply chains for agricultural commodities with their various constraints such as production lead time, seasonal production, and methods of storage are limited in the extent to which techniques like Just-in-Time (JIT) inventory management can be applied. It is beyond the ability of producers to control harvest time and many agricultural products are perishable so that they can incur exceptional losses in storage if they are not handled correctly. This is a source of additional costs and inefficiency in supply chain management. The purpose of this study is to reduce or eliminate such sources of loss and inefficiency and to identify success factors for the JIT inventory management system where it can be applied for agricultural products. Where ]IT techniques can be applied in supply chain management for agricultural products, costs such as transportation, inventory, and storage losses can be reduced with concurrent increases in efficiency. In the paper, some of the problems associated with applying ]IT inventory control methods in supply chain management for agricultural commodities will be reported through a series of case studies.

• Journal of the Korea Safety Management & Science
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• v.11 no.3
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• pp.113-119
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• 2009

본 연구는 공급자(supplier), 중간분배자(retailer/distributor) 그리고 고객(customer)으로 구성된 2 단계 공급사슬을 대상으로 공급자가 수요 증대를 목적으로 중간분배자에게 일정기간 동안 제품대금에 대한 지불 연기를 허용한다는 가정 하에 중간분배자의 최적 재고정책 결정을 위한 재고 모형을 다루었다. 소비성 상품의 경우, 고객의 수요는 일반적으로 상품 진열대에 진열되어있는 상품의 재고량에 많은 영향을 받는 것으로 알려져 있다. 따라서 본 연구에서는 이와 같은 상황을 고려하여 고객의 수요가 중간분배자의 재고량에 영향을 받는다는 가정 하에 재고 모형을 설계하였고, 모형 분석을 통하여 이익을 최대화하는 경제적 주문량 결정 방법을 제시하였다. 또한 예제를 통하여 제시된 해법을 적용하고, 그 타당성을 보였다.

• Journal of the Korea Safety Management & Science
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• v.3 no.1
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• pp.35-44
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• 2001

Today's environment of enterprise is changing. They have to face customers' demands with the right product, the right service and supply them at the right time. And aIso cut down logistics and inventory cost and bring up the Profit as much as they can. This means the change of putting enterprise first in importance to putting customer first in importance. therefore to correspond to customer's demand, shorting lead time is becoming a essential condition. The answer to this changes of environment is supply chain management In this study, we use Goldratt's drum-buffer-rope scheduling in between manufacturer and supplier. And when shortage of inventory occur, search for the supply chain's CCR. Pressing CCR for more production, and supply Inventory from logistic center to guide for inventory buffing. using logistic warehouse between manufacturer and supplier, can execute function of buffer.

• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.702-707
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• 2006

There have been certain extent of material inventory in construction site because of difficulties in ordering by small quantity, strategy of securing future requirements and prevention of delay. However, carrying these inventory entails a financial cost called inventory holding cost and decrease construction productivity, so proper inventory management in construction industry is important for construction efficiency and cost reduction. This study tries to find analytical method of inventory management. It includes ordering decision which decide how much to order and when to order. Setting these strategies including deciding safety inventory, input and ouput variability are able to controled.

• Journal of Korean Port Research
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• v.14 no.1
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• pp.37-45
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• 2000

Centralized safety stock in a periodic replenishment system which consists of one central warehouse and m regional warehouse can reduce backorders allocating the centralized safety stocks to regional warehouse in a certain instant of each replenishment cycle. If the central warehouse can not monitoring inventories in the regional warehouse, then we have to predetermine the instant of allocation according to demand distribution and this instant must be same for all different replenishment cycle. However, transition of inventory level in each cycle need not to be same, and therefore different instant of the allocation may results reduced shortage compare to the predetermined instant of allocation. In this research, we construct a dynamic model based on the assumption of monitoring inventories in the regional warehouse everyday, and develop an algorithm minimize shortage in each replenishment cycle using dynamic programming approach.

• Journal of the Korean Geotechnical Society
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• v.25 no.12
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• pp.27-35
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• 2009

KICT (Korea Institute of Construction and Technology) and KISTEC (Korea Infrastructure Safety and Technology Corporation) have been carrying out inventory survey on cut slopes along national roads since 2006. Unlike precision safety check, cut slope inventory survey is a simple check about cut slope's characteristics with the naked eye to collect the data base of slope maintenance. Inventory survey is classified into general status, cut slope characteristics and inspector opinions. The inventory data are analyzed to identify dangerous slopes and decide a safety ranking. In this paper, we performed a correlation analysis using SPSS (ver.15) about the 10,461 cut slope inventory data which are collected in Kangwondo and Chungcheongdo from 2006 to 2008. We calculated the correlation coefficient between cut slope inventory data and the danger score derived from the data. And we evaluated cut slope inventory data which have the more influence on the danger degree of cut slope. According to results of correlation analysis, we found that inventory data influencing cut slope danger degree are stuck and fallen rock, orientation of discontinuity and angle of upper slope. And these data are slightly different by regionally. Later on, if inventory research is finished, we will understand regional characteristics of cut slopes.

• Journal of Information Technology Services
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• v.10 no.3
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• pp.49-59
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• 2011

A ship scheduling model is presented for the raw material transportation problem with yard storage constraints in a steel mill. The problem is formulated as 0, 1 mixed integer programming considering such constraints as loading port conditions, ship size and hold capacity, unloading conditions, and yard storage space. In addition, inventory related constraints including safety stock are taken into consideration to support the continuous operations of steel making process. The proposed model has been implemented and applied successfully to a real world problem, and its results show the improvement of performance compared to the traditional method. For example, the arrival dates of ships are determined satisfying the constraints. The total inventory level is minimized at the stock yard as a result. Also, the safety inventory level is always kept at the planning stage, and the standard deviation of total inventory level is reduced significantly. Further research is expected to develop efficient heuristics to have a better response time for even larger scale problems.

• Proceedings of the Korean Geotechical Society Conference
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• 2008.03a
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• pp.858-862
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• 2008

KICT has been carrying out inventory research on the cut slopes of national roads. Inventory research results are basic data used in cut slope management system. Inventory data are classified by general status, cut slope characteristics and inspector opinion. Cut slope inventory data are utilized to figure out dangerous slopes and decide survey ranking of detailed safety diagnostication. This paper drew the distribution of dangerous cut slopes using inventory data in Chungcheongdo, then verified an efficiency on distribution of dangerous cut slopes by comparing occurrence frequency of real collapsed cut slopes.