• The Journal of Industrial Distribution & Business
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• v.11 no.10
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• pp.39-48
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• 2020

Purpose: Management of water is a crucial issue globally and is becoming more critical due to climate change. The purpose of this study is to explore water resource management by considering price and water usage based on river basins and to suggest more efficient residential water demand management in South Korea. Research Design, data, and methodology: This study applied data of water usage and water price of 15 regions in four major river basins by considering up and downstream locations from 1997 to 2017 collected by Ministry of Environment in Korea. This study applied regression analyses, ANOVA, and 2-Way ANOVA to verify its claims. Results: The results found that effects of price on water usage showed significant in many cities. The results also showed that means of water usages differ based on location (upstream and downstream) and river basins. Conclusion: The findings provide important policy and management implications for the improvement of water resource management in terms of demand. The results also indicate that water price should be reconsidered by comparing water price levels with those of OECD countries. Furthermore, the results imply that water management in Korea needs to improve in terms of supply to cope with climate change.

• Health Policy and Management
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• v.29 no.3
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• pp.332-341
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• 2019

Background: This study analyzes the effects of the individual's health behavior on the health and the medical demand for the management of health and medical expenses. Methods: This study uses the Korea Health Panel Survey data from 2010 to 2015. We utilize the panel ordered logit model and the panel Tobit model with the subjective health status and the medical expenses as the dependent variables. Results: Chronic diseases would cause the deterioration of his or her health and the increase in medical expenses. Smoking and drinking alcohol would deteriorate one's health. The total amount of cigarettes increases medical expenses. Exercises could make people healthier, whereas excessive exercise might increase medical expenses. Private health insurance would increase medical expenses. Conclusion: Since health could reduce the medical expenses, people should promote one's health by changing one's behavior for health.

• Journal of Korean Institute of Industrial Engineers
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• v.37 no.3
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• pp.216-228
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• 2011

A logistics system involving a supplier who produces and delivers a single product and a buyer who receives and sells the product to the final customers is analyzed. In this system, the supplier and the buyer establish a contract which specifies that the supplier will deliver necessary amount of the product to raise inventory up to a specified position at the beginning of each period. A new periodic order-up-to-level inventory control policy specifically designed for nonstationary end customer's demand is proposed for the system. Simulations are used to test the efficiency of the proposed policy. An analysis of the test results reveals that the proposed policy performs much better than does the existing order-up-to-level policy, especially when the demand is nonstationary.

• Health Policy and Management
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• v.32 no.1
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• pp.73-93
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• 2022

Background: Appropriate physician workforce projection through reasonable discussions and decisions with a broad view on supply and demand of the workforce, thus, is very important for high-quality healthcare services. The study expects to provide preliminary research data on the workforce diagnosis standard model for Korean physician workforce policy decision through more flexible and objective physician workforce projection in reflection of diverse changes in healthcare policy and sociodemographic environments. Methods: A low flow rate through the causal map was developed, and an objective workforce demand projection from 2019 to 2040 was conducted. In addition, projections by scenarios under various situations were conducted with the low flow rate developed in the study. Lastly, the demand projection of the physician workforce by region of 17 cities and provinces was conducted. Results: First, demand of physicians in 2019 was 110,665, 113,450 in 2020, 129,496 in 2025, 146,837 in 2030, 163,719 in 2035, and 179,288 in 2040. Second, the scenario for the retirement of baby boomers led to a decrease in the growth rate due to time delay. Third, Seoul and Gyeonggi-do account for a high percentage of demand, a very high upward trend was identified in Gyeonggi-do, and as a result, the projection showed that the demand of the physician workforce in Gyeonggi-do would worsen over time. Conclusion: This study is meaningful in that rational and collective physician workforce supply and demand and its imbalance in workforce distribution were verified through various projections by scenarios and regions of Korea with System Dynamics.

• Health Policy and Management
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• v.3 no.1
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• pp.146-168
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• 1993

The study was conducted to project supply and demand of the nurses till year 2010 based on analysis of supply and demand of nurses up to year 1991. Results of the study will provide invaluable information for nurses manpower planning as well as overall health manpower planning for the 21th century. It is projected that nurses will be oversupplied based on the current prductivity which is undesirable situation if the quality of care is considered, and undersupplied based on the the medical law as well as optimal productivity. Thus, it is desirable to increase active supply of nurses. One of the ways of increasing active supply would be increasing the size of training and education. But, considering low employment rate of nurses which is about 59% better way of solving problems related to nurses shortage would be improvement in nurses' employment rate. According to simulation study done as part of this study, if nurses' employment rate goes up to 80%, there is no need for increasing the size of training to meet the demand at the level of medical law.

• 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.

• Industrial Engineering and Management Systems
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• v.14 no.2
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• pp.129-158
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• 2015

It is necessary for retailers to determine the optimal ordering policy of products considering supply disruptions due to a natural disaster and a production process failure as quality and machine breakdowns. Under the situation, a dualsourcing supply chain (DSSC) is one of effective SC for retailers to order products reliably. This paper proposes the optimal ordering policy of a product in a DSSC with a retailer and two manufacturers. Two manufacturers may face supply disruptions due to a natural disater and a production process failure after they received the retailer's order of products. Here, two scenarios of demand information of products are assumed: (i) the demand distribution is known (ii) mean and variance of the demand are known. Under above situations, two types of DSSC are discussed. Under a decentralized DSSC (DSC), a retailer determines the optimal ordering policy to maximize his/her total expected profit. Under the integrated DSSC (ISC), the optimal ordering policy is determined to maximize the whole system's total expected profit. Numerical analysis investigates how demand information and supply disruptions affect the optimal decisions under DSC and ISC. Besides, profitability of supply chain coordination adjusting the wholesale price is evaluated to encourage the optimal decision under ISC.

• Journal of Korean Society for Quality Management
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• v.14 no.1
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• pp.47-52
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• 1986

Slow-moving items whose cost is so high and/or whose demand is so low the optimal policy is to place a reorder immediately whenever a demand occurs. This is a continuous review (S-1,S) inventory policy which means that whenever a demand for an arbitrary number of units is accepted, a reorder is placed immediately for that number of units. This paper show optimal inventory level ($S^*$) when arrivals tend to get discouraged and recommend practical difficulties of deciding stockholding policy of slow-moving items. Also, a simple numerical example is provided.

• Health Policy and Management
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• v.25 no.1
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• pp.53-62
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• 2015

Background: Supplier induced demand (SID) indicates the case when doctors increase the demand of the patients, following their (physicians') own best interests rather than patients'. This may occur when asymmetry of information exists between suppliers and consumers. This study aims to confirm whether SID exists in the Korean setting, particularly by dividing SID into both 'induced demand effect' and 'availability effect.' Methods: Induced demand effect and availability effect are differentiated following Carlsen & Grytten's theoretical frame which divides doctor density regions into high and low ones. Results: Positive correlation between doctors' density and utilization of their services was found, which could be interpreted as 'availability effect.' Conclusion: The result suggests that additional medical use for additional doctor, particularly in the area of low doctor density, can be interpreted to occur to meet the basic medical need of the people rather than as a result of unnecessary induced demand. It is important to make more medical doctors provided and to distribute them appropriately across the region in such a country like Korea where doctor's density is relatively low.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1994.04a
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• pp.427-431
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• 1994

The objective of this paper is to provide an inventory control policy for the system that carries a single item with a multiple demand classes, when the demand is Poisson distributed random variable. The inventory control process includes the process of determining the reorder point, and the process of inventory control during the lead time. The goal of the optimization process is to achieve the service level of each demand class as well as the system-wide total service level at a preset desired service level while sustaining a minimum average inventory.