• The Journal of the Korea institute of electronic communication sciences
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• v.15 no.6
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• pp.1145-1150
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• 2020

After the Davos Forum, the recent 4th Industrial Revolution has become an area of interest to countries around the world. Among the technologies of the 4th industrial revolution, the ubiquitous computing environment requires a convergence environment of various devices, networks, and software technologies, and the RFID technology that identifies objects among the IoT technology fields is applied to all industries and has a competitive edge. Systems to which RFID technology is applied are being used in various industrial fields, especially! It is efficiently used for accurate inventory management and SCM management in the field of distribution and logistics. If the RFID system is built in a cloud-based environment, it will be possible to secure reliability in distribution management in consideration of an effective logistics management system and economic feasibility. This study is a study on the RFID system in a cloud computing environment to reduce the cost of operating or maintaining an application server to improve the economy and reliability.

• Industrial Engineering and Management Systems
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• v.12 no.3
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• pp.281-287
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• 2013

In this paper, we introduce a roots method that uses the roots inside the unit circle of the associated characteristics equation to evaluate the steady-state system-length distribution at three epochs (pre-arrival, arbitrary, and post-departure) and sojourn-time distribution in GI/PH/1 queueing model. It is very important for an air base to inspect airplane oil because low-quality oil leads to drop or breakdown of an airplane. Since airplane oil inspection is composed of several inspection steps, it sometimes causes train congestion and delay of inventory replenishments. We analyzed interarrival time and inspection (service) time of oil supply from the actual data which is given from one of the ROKAF's (Republic of Korea Air Force) bases. We found that interarrival time of oil follows a normal distribution with a small deviation, and the service time follows phase-type distribution, which was first introduced by Neuts to deal with the shortfalls of exponential distributions. Finally, we applied the GI/PH/1 queueing model to the oil train congestion problem and analyzed the distributions of the number of customers (oil trains) in the queue and their mean sojourn-time using the roots method suggested by Chaudhry for the model GI/C-MSP/1.

• Journal of Korean Society for Quality Management
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• v.19 no.2
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• pp.96-107
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• 1991

At the design stage of a plant, the plausible causes and pathways of release of hazardous materials are not clearly known. Thus there exist large amount of uncertainties on the consequences resulting from the operation of a fusion plant. In order to better handle such uncertain circumstances, we utilize the Probabilistic Risk Assessment(PRA) for the safety analyses on fusion power plant. In this paper, we concentrate on the tritium release accident. We develop a simple model that describes the process and flow of tritium, by which we figure out the locations of tritium inventory and their vulnerability. We construct event tree models that lead to various levels of tritium release from abnormal initiating events. Branch parameters on the event tree are assessed from the fault tree analysis. Based on the event tree models we construct influence diagram models which are more useful for the parameter updating and analysis. We briefly discuss the parameter updating scheme, and finally develop the methodology to obtain the predictive distribution of consequences resulting from the operating a fusion power plant. We also discuss the way to utilize the results of testing on sub-systems to reduce the uncertain ties on over all system.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.37 no.1
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• pp.60-67
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• 2014

This paper considers an inbound ordering and outbound dispatching problem for multi-products and multi-vehicles in a third-party distribution center. The demands are dynamic over a discrete and finite time horizon, and replenishing orders are shipped in various transportation modes and the freight cost is proportional to the number of vehicles used. Any mixture of products is loaded onto any type of vehicles. The objective of the study is to simultaneously determine the inbound lot-sizes, the outbound dispatching sizes, and the types and numbers of vehicles used to minimize total costs, which consist of inventory holding cost and freight cost. Delivery time window is one of the general dispatching policies between a third-party distribution center and customers in practice. In the policy, each demand of product for a customer must be delivered within the time window without penalty cost. We derive mixed integer programming models for the dispatching policy with delivery time windows and on-time delivery dispatching policy, respectively and analyze the effect on a dispatching policy with delivery time windows by comparing with on-time delivery dispatching policy using various computational experiments.

• Korea Journal of Hospital Management
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• v.4 no.1
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• pp.1-20
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• 1999

Since the late 1980s, there have been radical changes in the managerial environment of Y University Medical Center(YUMC). Externally, the competition among hospitals has intensified due to the establishment of universal health insurance in 1939 and the entrance of large enterprises into the health care industry in the early 1990s. In addition, government regulation of medical institution is becoming stricter. Also, consumer groups have continued to demand the respect for patient rights and improvement of the quality of medical services. Internally, the financial condition of YUMC has worsened, not only because weak control and poor mediation in its large-scale structure have made its operation inefficient, but also because the rates of increase in the prices of goods and labor have grown faster than any increases in revenues. This study on materials management at YUMC presents a way for YUMC to reduce costs and increase its productivity, thereby overcoming its financial difficulties and dealing with external pressures. This study utilized the case studies of the materials purchasing and medical supply management in the United States and the comparative analysis of management to suggest short-term and long-term alternatives for innovation in YUMC. The goals of the short-term alternatives for innovation are to centralize the purchasing and supply departments and to simplify the decision-making processes. Through these attempts, it is estimated that YUMC's costs could be reduced by $600,000 per year. In the long-term, it is necessary to consider introducing a Supply Processing Distribution(SPD) system and setting up a centralized electronic system for supply and inventory management, although it is difficult to estimate the effect of cost-cutting because of the lack of analysis data. Thus, YUMC should thoroughly analyze initial investment costs and economical efficiency generated from long-term alternatives.

• The Journal of Society for e-Business Studies
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• v.14 no.4
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• pp.267-286
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• 2009

Most companies in automobile part industry need a SCM (Supply Chain Management) system under the cooperation with suppliers for assembling a automobile. Automobile part industry has a industry feature of hierarchical structure like 1st, 2nd, 3rd vendors. Recently, new cases to implement RFID (Radio Frequency Identification) technology appear in various areas required for integrated information system. Especially, supply chain environment in automobile part industry turns toward ubiquitous computing environment. Most companies in automobile part industry are interested in implementing RFID-based supply chain management system, which makes them shorten the business process, share the transaction information, and enhance the collaborative relationship between trading partners. This paper intends to implement RFID technology in the physical distribution area of automobile part industry such as warehousing, delivering, inventory management. The purpose of this paper is to improve the collaborative relationship of supply chain network using RFID applied to u-SCM system in ubiquitous computing environment. The contribution of this paper is to suggest a new system approach to transform existing business process into new business process through designing and implementing a RFID based SCM system using UML techniques.

• Korea Journal of Hospital Management
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• v.4 no.2
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• pp.266-285
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• 1999

The purpose of this study is to identify influencing factors for successful introduction, implementation and management of HMRPS through assessment of the employees attitude toward HMRPS in technical, administrative, and organization behavioral areas. Data were collected from 157 HMRPS employee members' self-reporting questionnaire in three university hospitals in the city of Seoul and Kyonggi Province from November 5 to November 10, 1997. Relevant literature on industry company MPR system theory was reviewed to develop the theoretical framework. The results were as follows: The employee's recognition of tangible benefit were more significantly influenced success than intangible benefit for successful operation relating the HMRPS. Concerning the employee's recognition of the successful HMRPS and the factor of influenced success was significantly positive correlation between tangible and intangible benefits and success factor in technical, administrative, and organizational behavior area. This study showed that major factor affecting the employee's recognition of tangible and intangible benefit for successful HMRPS. For tangible benefits; Success factors in the technical areas were quality of the data and information, efficiency of inventory management and rescheduling of operation plan. Success factors in the administrative areas were: role of top management. Success factors in the organization behavioral areas were; simplicity of the HMRPS, human resistance to change. For intangible benefits; Success factors in the organization behavioral areas were; user involvement, simplicity of HMRPS, human resistance to change. Futhermore as the exact evaluation of successful factors of HMRPS implement is needed, research for the development of systemic variables of physical distribution system control, methods, capacity of system, duration and other environment in many of 30 hospitals or more, and for the empirical study for HMRPS.

• Journal of the Korean Operations Research and Management Science Society
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• v.30 no.3
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• pp.81-93
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• 2005

This paper models supply chain uncertainties in the dynamic Newsboy Problem context. The system consists of one supplier and one retailer who place an order to the supplier every period. Demand uncertainty is modeled as stochastic period demand, and supply uncertainty as the uncertainty in quantities delivered by the supplier. The supplier delivers exactly the amount ordered by the retailer with probability of $\beta$ and the amount minus K with probability of $(1-\beta)$ We formulate the problem as a dynamic programming problem and derive the first-order optimality condition. Through a numerical study, we measure the extent to which the cost decrease due to the reduction in supply uncertainty depends on the level of demand uncertainty. One of the most important findings In this paper is that this cost decrease is relatively small if demand uncertainty is kept high, and vice versa. We also backup this numerical result by analyzing the distribution of ending Inventory under the supply and demand uncertainties.

• Industrial Engineering and Management Systems
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• v.13 no.1
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• pp.1-14
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• 2014

With a steep increase of the global disaster relief efforts around the world, the relief supply chain and humanitarian logistics play an important role to address this issue. A broad overview of operations research ranges from a principle or conceptual framework to analytical methodology and case study applied in this field. In this paper, we provide an overview of this challenging research area with emphasis on the corresponding optimization problems. The scope of this study begins with classification by the stage of the disaster lifecycle system. The characteristics of each optimization problem for the disaster supply chain are considered in detail as well as the logistics features. We found that the papers related to disaster relief can be grouped in three aspects in terms of logistics attributes: facility location, distribution model, and inventory model. Furthermore, the literature also analyzes objectives and solution algorithms proposed in each optimization model in order to discover insights, research gaps and findings. Finally, we offer future research directions based on our findings from the investigation of literature review.

• Journal of Distribution Science
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• v.17 no.9
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• pp.5-13
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• 2019

Purpose - This study investigates the key features of Quick Response as the fundamental form of supply chain collaboration by reviewing the selected past studies. Based on the findings from the literature review, this study provides the guideline for future researchers and business practitioners who search for more advanced collaboration programs. Research design, data, and methodology - This study conducts the literature review on the past studies that had researched Quick Response. The selected studies are analyzed in terms of how to represent Quick Response in the models and which issue to address. Results - This study finds that the past studies lack a unified concept of Quick Response, and they fail to provide the consistent guideline on how to run this program in practices. The literature review also shows that only a small number of research issues has been addressed by most researchers. Conclusions - On the purpose of figuring out the real value of Quick Response, this study suggests that future studies apply its extensive application to the entire supply chain system. This study also shed light on the potential of Quick Response to be a more advanced supply chain collaboration program with additional collaborative functions other than information sharing.