• Proceedings of the KIPE Conference
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• 2005.07a
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• pp.102-105
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• 2005

For transferring the primary power to the secondary one, the high frequency series resonant converter has been widely used for the contactless power supply system. However, the high frequency series resonant converter has the disadvantages such as the low efficiency, the high voltage gain characteristics and deviation of the phase angle in the overall load range. To improve this disadvantage, In this paper, the characteristics of the high efficiency and unit voltage gain as well as in phase are revealed in the proposed three-level LCLC ( Inductor - Capacitor - Inductor -Capacitor)resonant converter. The results are verified on the simulation based on the theoretical analysis and the 4kW experimental prototype.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.05a
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• pp.454-457
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• 2004

The high degree of uncertainty in customer demands forces companies of today to equip with a flexible and adaptable structural organization. It also has an influence on the configuration of the company's supply chains, since the members in supply chains are dependent to the goods customers need. If a company can not come up with the customers' requirements and their level of satisfaction, the competitiveness of the company will be weaken in the market places. To meet such conditions, therefore, reconfiguration of supply chains should be considered as an important factor in a complex, dynamic, and fluctuating market environment. In this paper, therefore, we have adapted a fractal concept to SCM to facilitate reconfiguration of supply chains. To do so, we have first introduce fractal-based SCM, referred to as fSCM. Then, we have described definitions of the reconfigurability in supply chains and the methodology of Dynamic Restructuring Process (DRP) in supply chains including specific strategies and constraints. An exemplary model will also be briefly illustrated to demonstrate how supply chains conduct DRP autonomously.

• Fire Science and Engineering
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• v.24 no.6
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• pp.20-27
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• 2010

In smoke control systems the amount of air supply is almost the same as that of smoke exhaust. This study analyzed the effect of supply air velocity on the smoke exhaust behavior using FDS tool. The results showed that fire plume can be disheveled by the rapid air velocities developed when the air supply inlet is located near the fire plume. Disheveled smoke caused the rapid descent of smoke layer level and the reduced visibility. To increase the efficiency of smoke exhaust systems supply air inlet should be located sufficiently far from the location of the fire plume.

• Industrial Engineering and Management Systems
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• v.11 no.1
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• pp.54-69
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• 2012

Chan and Qi (SCM 8/3 (2003) 209) developed an innovative measurement method that aggregates performance measures in a supply chain into an overall performance index. The method is useful and makes a significant contribution to supply chain management. Nevertheless, it can be cumbersome in computation due to its highly complex algorithmic fuzzy model. In aggregating the performance information, weights used by Chan and Qi-which aim to address the imprecision of human judgments-are incompatible with weights in additive models. Furthermore, the default assumption of linearity of its scoring procedure could lead to an inaccurate assessment of the overall performance. This paper addresses these limitations by developing an alternative measurement that takes care of the above. This research integrates three different approaches to multiple criteria decision analysis (MCDA)-the multiattribute value theory (MAVT), the swing weighting method and the eigenvector procedure-to develop a comprehensive assessment of supply chain performance. One case study is presented to demonstrate the measurement of the proposed method. The performance model used in the case study relies on the Supply Chain Operations Reference (SCOR) model level 1. With this measurement method, supply chain managers can easily benchmark the performance of the whole system, and then analyze the effectiveness and efficiency of the supply chain.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2008.10a
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• pp.267-284
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• 2008

Consider a supply chain where products are produced at a manufacturing system, shipped to a distribution center, and then supplied to customers. The distribution center controls inventory based on a base-stock policy, and whenever a unit of product is demanded by a customer, an order is released to the production system. Unsatisfied demand is backordered, and the inventory and backordered units are a function of the base-stock level. The manufacturing system is modeled as an M/M/s/c queueing system, and orders exceeding the limited buffer capacity are blocked and lost. The throughput of the manufacturing system and the steady state distribution of the outstanding orders are functions of number of servers and buffers of the manufacturing system. There is a profit obtained from throughput and costs due to servers and buffers of the manufacturing system, and also costs due to inventory positions of the distribution center, and we want to maximize the total production profit minus the total cost of the supply chain by simultaneously determining the optimal number of servers and buffers of the manufacturing system and the optimal base-stock level of the distribution center. We develope two algorithms, one analytical but without guarantee of the optimal solution and one optimal but without complete analytical proofs. The problem integrates strategic problem of the manufacturing system with tactical problem of the distribution center in a supply chain.

• 한국전산유체공학회:학술대회논문집
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• 2005.10a
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• pp.39-44
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• 2005

In HANARO, a multi-purpose research reactor of 30 MWth, the emergency water supply system consists essentially of an emergency water storage tank located in the level of about thirteen meter (13 m) above the reactor core, a three inch ('3\%') diameter water injection pipe line including injection valves from the tank to the reactor cooling inlet pipe and a test loop to do periodic system performance test. When the water level of the reactor pool comes down to the extremely low due to a loss of reactor pool water accident the emergency water stored in the tank should be fed to the core by the gravity force and at that time the design flow rate is eleven point four kilogram per second (11.4 kg/s). But it is impossible periodically to measure the injection flow rate under the emergency condition because the normal water level should be maintained during the reactor operation. This paper describes a flow network analysis to simulate the flow rate under the emergency condition. As results, it was confirmed through the analysis results that the calculated flow rate agrees with the design requirement under the emergency condition.

• Journal of the Korean Operations Research and Management Science Society
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• v.32 no.1
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• pp.93-104
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• 2007

We consider a supply chain where products are shipped to warehouse from manufacturing system to customers. Products are supplied from either in-house regular manufacturing or the secondary source such as subcontractor. The inventory in warehouse is controlled by base-stock policy, that is, whenever a demand arrives from customer, an order is released to the manufacturing system. Unsatisfied demand is backlogged. The manufacturing system is modeled as M/M/s+1/c queueing system, and the orders exceeding the given limit care blocked and lost. The steady state distribution of the outstanding orders and the throughput of the manufacturing system are functions of the level of engagement In the secondary source. There is a profit obtained from throughput and cost not only due to the engagement of the secondary source in the manufacturing system but also inventory positions. We want to maximize the total production profit minus the total cost of the production system by simultaneously determining the optimal level of engagement of the secondary source and the optimal base-stock level of the inventory. We develop two algorithms : one without guarantee of the optimal solution but with the small number of computations, the other optimal but with more computations.

• Journal of the Korean Data and Information Science Society
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• v.25 no.4
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• pp.755-767
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• 2014

Recently, many firms have introduced information and communication technology (ICT) into supply chain. However, existing studies have not yet insisted definite conclusion with respect to ICT impact on supply chain. Thus, this study subdivides supply chain performance which previous researchers have studied comprehensively while suggesting perspective of the use of firm's ICT capabilities. We classify ICT capabilities into four types of group and then analyze the difference between groups regarding each factor of supply chain performance by ANOVA analysis and Tukey method. As a result of analysis, the group in which all ICT capabilities are high shows the highest level of integration and flexibility performance among supply chain performances. On the other hand, the group in which all ICT capabilities are low presents the lowest level of integration and flexibility performance. We also provide more precise and specific information with practitioners by analyzing the difference between groups with regard to detailed measurements on integration and flexibility variables.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.43 no.1
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• pp.87-109
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• 2020

Supply chain management can be defined as an information system that connects the inside and outside of a company. Its purpose is to systematically and strategically manage the flow of information, resources and services to improve the long-term performance of the entire organization, including individual companies connected to the supply chain, and the quality of service provided to customers. The ultimate goal of SCM is to create synergy through organic integration of supply and demand based on cooperation and collaboration with stakeholders in the supply chain. This study is based on the hypothesis that the company's management performance will improve as the level of SCM improves. Most of the previous studies dealt with the relationship between corporate performance and SCM in the IT area. In this study, research was conducted through human capacity with IT system. The causal relationship was demonstrated, and there was a difference in the perception of the results of this study depending on whether or not smart factories were consulted in the era of the 4th Industrial Revolution. There is a need to examine the links between management's value chain and its causal relationship.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.05a
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• pp.155-156
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• 2021

The development history of China's big data is relatively short, and it has only been ten years so far. Although the application level of big data in real life is not high, some achievements have been made in the supply chain. Various kinds of data will be generated in the actual operation of the supply chain. If these data can be effectively classified and used, the "bullwhip effect" of the operation of the supply chain can be also effectively improved. Thus this paper proposes the development of a supply chain collaborative inventory management model and application framework using big data.