• Journal of the Korea Safety Management & Science
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• v.20 no.3
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• pp.37-46
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• 2018

According to enhancement of roles and functions of enterprises' distribution centers, recent trend of distribution centers are specialization and diversification which have generated lots of new distribution center building or expansion of the existing ones and led attention on stock transfer importance in case of distribution center relocation. This thesis is a study for how to reduce stock transfer leadtime in order to minimize business risk and how to increase inventory accuracy when stock ownership is transferred in case of distribution center relocation, and to provide inventory accuracy management methods and inventory in/out management types, detailed definition to evaluate level for inventory accuracy management and pros/cons by inventory in/out management type assuming 'the higher inventory accuracy before stock transfer, the shorter stock transfer leadtime when distribution center is relocated'. This thesis provides detailed procedure to secure an absolute stock transfer leadtime and process to confirm hugh inventory accuracy by stakeholders which should be sloved by Task Force Team for stock transfer in case of distribution center relocation.

• Management Science and Financial Engineering
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• v.18 no.2
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• pp.1-4
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• 2012

We study optimal trading strategy of a market maker with stock inventory. Following Avellaneda and Stoikov (2008), we assume the stock price follows a normal distribution. However, we take a constant expected rate of the stock return and assume that the stock volatility is an inverse function of the stock price level. We show that the optimal bid-ask spread of the market maker is wider for a higher expected rate of stock returns.

• Proceedings of the Safety Management and Science Conference
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• 2005.11a
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• pp.194-198
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• 2005

Inventory information system is providing the benefits of smoother demand, lower inventories(work in process, safety stock) and reduced costs. This study focused on improvement of safety level inventory efficiency by inventory information system. The results indicated that inventory information system allowed the company to serve its customers more surely and efficiently.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.36 no.1
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• pp.96-102
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• 2013

This paper makes a detailed comparison between two metrics designed for measuring customer's satisfaction in the retail industry. The first metric, which is called the customer service level, has not been widely used due to the intrinsic requirement on the parameter assumption(s) of the demand distribution. Unlike the customer service level metric the in stock ratio metric does not require any requirements on the demand distribution. And the in stock ratio metric is also very easy to understand the meaning. To develop the detailed planning activities for business with the in stock ratio metric on hand one should collect some information as following : 1) POS (Point of sales) data, 2) Inventory Data 3) Inventory Trend.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.385-391
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• 2017

This study was conducted to estimate litter carbon stock change from the National Forest Inventory (NFI) data for national greenhouse gas inventory report. Litter carbon stocks were calculated from the NFI dataset in NFI5 (2008) and NFI6 (2013) in Gangwon province. Total carbon stock change of litter was $0.68{\pm}0.71\;t\;C/ha$ from NFI5 (2008) to NFI6 (2013), however, there was no significant difference between the both dataset at 2008 and 2013 year. Litter carbon stock of coniferous stands was higher than deciduous stands in NFI5 (2008) and NFI6 (2013) (P<0.05). This study was limited to pilot study, so we will assess litter carbon stock using more complete data from NFI systems. It can be used as data sources for national greenhouse gas inventory report on forest sector.

• Journal of Climate Change Research
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• v.7 no.4
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• pp.485-492
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• 2016

For reporting national greenhouse gas inventory in forest sector, the forest growing stock from the National Forest Inventory (NFI) system has used as activity data sources. The National Forest Inventory system was changed from rotation system by province to annual system by 5 years across the country. The forest growing stocks based on the new inventory system produced a different trend compared to the previous estimations. This study was implemented to recalculate previous forest growing stocks for time series consistency at a national level. The recalculation of forest growing stock was conducted in an overlap approach by the IPCC guideline. In order to support the more consistency data, we used calibration factors between applied stand volumes in 1985 and 2012, respectively. As a result, the time series of recalculated forest growing stock was to be consistency using the overlap approach and the calibration factor with the lower middle/middle site index. According to the applied overlap period, however, we will recalculate activity data using more complete data from national forest inventory system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.38 no.3
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• pp.8-13
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• 2015

One of the most usual indicators to measure the performance of any inventory policy is the mean physical stock. In general, when estimating the mean physical stock in periodic review inventory systems, approximate approaches are often utilized by practitioners and researchers. The mean physical stock is generally calculated by a simple approximation. Still these simple methods are frequently used to analyze various single stockpoint and multi-echelon inventory systems. However, such a simple approximation can be very inaccurate. This is particularly true for low service levels. Even though exact methods to calculate the mean physical stock have been derived, they are available for specific cases only and computationally not very efficient, and therefore less useful in practice. In literature, approximate approaches, such as the simple, the linear, and Simpson approximations, were derived for the periodic review inventory systems that allow backorders. This paper modifies the approximate approaches for the lost sales case and evaluates the modified approximate approaches. Through computational experiments, average (and maximum) percentage deviations of mean physical stock between the exact method and the modified approximations are compared in the periodic review inventory system with lost sales. The same comparison between the modified and the original approximations are also conducted, in order to examine the performance of modified approximations. The results show that all modified approximations perform well for high service levels, but also that the performance may deteriorate fast with decreasing service level. The modified Simpson approximation is clearly better. In addition, the comparison between the modified and the original approximations in the periodic review inventory system with lost sales shows that the modified approximation outperforms the original approximation.

• Journal of the Korean Operations Research and Management Science Society
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• v.15 no.1
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• pp.63-72
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• 1990

This problem in this paper concerns the determination of safety stock for multi-echelon invenetory system. In this model the criterion is to minimize system safety stock subject to a service level constraint and expected annual total cost. Then, safety stock is determined by minimizing expected annual total cost and satisfying given service level. This expected annual total cost is obtained by expected total inventory holding cost plus the expected total stockout cost. Numerical example is given in a three-echelon inventory system. The results obtained by the use of the Hill Algorithm.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.4
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• pp.71-81
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• 2005

This Paper focuses on the effects of outside competition on an optimal echelon base stock level in a two stage supply chain. This is new in that we have been studying the effects of inside competition within a supply chain up to now. It is known that the optimal echelon base stock level with inside competition within a supply chain is less than the global optimal echelon base stock level without inside competition. This is due to the ' public goods ' nature of inventory. That is, more inventory is better, but one wants the other to invest more, thus resulting in under-investment. However, this phenomenon becomes weaker as outside competition increases. We show that as outside competition becomes stronger, the ' public goods ' effects decrease and the optimal echelon base stock level increases. If the level of competition is sufficiently high, the optimal echelon base stock level goes even higher than the global optimal echelon base stock level. We develop a theoretical model for the analysis and conduct a numerical analysis.

• International Journal of Advanced Culture Technology
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• v.3 no.2
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• pp.1-14
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• 2015

The purpose of this paper is to reveal two problems in the existing inventory systems in retail market, and to suggest a Two-Bin System under Automatic Ordering System considering only base-stock. Large retailers already have a sophisticated inventory system based on an automatic ordering principle. However, why does the out-of-stock (OOS) happen in large discount stores in spite of having a good inventory system? This paper suggests two systems after finding the root causes concerning the previous question. For evaluating the performance of each system, the random 200 data set in each sample group was generated from MINITAB 16 and obeyed the Poisson distribution. The existing inventory system in retail market cannot help generating OOS due to indwelling contradiction in itself. The reasons are the ordering deadline and the relationship between ordering quantity and base stock. This paper also demonstrates that these previous studies on inventory fall into the closed loop. Also the paper shows that the performance of the replenishment policy was better than traditional methods dealing with ordering quantity and base stock.