• Proceedings of the KSR Conference
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• 2007.05a
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• pp.1244-1249
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• 2007

Pursuing sustainable development throughout society and industry and the field of environmental policy, each international organization or nation has performed international standardization projects on environmental management activities for their system as well as environmental assessment for a product such as life cycle assessment (LCA) and life cycle inventory database (LCI DB), and the environmental aspects have been increasingly demanded as crucial evaluation specifications. Moreover, the conventional environmental policy, which represents the direct-control, has been more dependent on the market forces and product itself after the Climate Change Convention., and the Integrated Product Policy (IPP, EU) is applied vigorously to strengthen global competitiveness of a product and to achieve the effect of environmental improvement for it. According to change of the international railway market, the value of Eco-Design has been increasingly important in developed countries including EU. Thus, each country is establishing its own guidelines, software and database for each product, and developing new policies through Eco-Design with practical results in marketing. To react this and develop Korean railway as an environment-friendly industry with priority to other transportation system as well as maintain high place in technology, the direction of RACE software development of main function is introduced, which is exclusively used for EMU to assess both environmental and economic aspects with LCA and eco-efficiency (EE).

• Journal of Digital Convergence
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• v.19 no.1
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• pp.343-348
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• 2021

This study investigated the method of constructing and combining blocks based on the atomic design system in order to propose a framework for rescue of a reusable design system. For that, I first looked at the necessity of a design system and examples of snow white, skeuomorphic design, flat design, and material design. In addition, molecules, atoms, organisms, templates and pages of atomic design using the principles of chemistry as metaphors were defined through literature studies. In order to implement a new framework, an interface inventory was constructed, and among them, font, color, image and control elements were extracted as core visual elements, and guidelines were defined, and molecular elements were classified and composed of atoms based on them. Blocks are constructed in the form of blocks based on the design pattern most used in the content inventory, and the framework is constructed to implement a layout based on a visual grid and design a page through a combination of blocks. The significance of this paper is that the new framework helps team consistency and collaboration by reusing blocks and supports file sharing and updating.

• Asian Journal of Atmospheric Environment
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• v.5 no.4
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• pp.278-291
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• 2011

Korea has experienced dramatic development and has become highly industrialized and urbanized during the past 40 years, which has resulted in rapid economic growth. Due to the industrialization and urbanization, however, air pollutant emission sources have increased substantially. Rapid increases in emission sources have caused Korea to suffer from serious air pollution. An air pollutant emissions inventory is one set of essential data to help policymakers understand the current status of air pollution levels, to establish air pollution control policies and to analyze the impacts of implementation of policies, as well as for air quality studies. To accurately and realistically estimate administrative district level air pollutant emissions of Korea, we developed a Korean Emissions Inventory System named the Clean Air Policy Support System (CAPSS). In CAPSS, emissions sources are classified into four levels. Emission factors for each classification category are collected from various domestic and international research reports, and the CAPSS utilizes various national, regional and local level statistical data, compiled by approximately 150 Korean organizations. In this paper, we introduced for the first time, a Korean national emissions inventory system and release Korea's official 2007 air pollutant emissions for five regulated air pollutants.

• The Journal of Asian Finance, Economics and Business
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• v.7 no.12
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• pp.863-867
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• 2020

This study was conducted on financial data of 38 economic groups listed on Vietnam's stock market for the period 2009 - 2019 and it aims to provide an empirical evidence on the impact of working capital management policy on performance in all phases of the economic cycle of Vietnamese economic groups. The study uses FGLS estimation method with 2 dependent variables ROA, GOP, independent variables including INV, AR, AP, CCC, dummy variable representing different phases of the economic cycle, variables Control includes CAT, CR, LEV, SZ, GR. Research shows that the greater the level of investment by companies in liquid assets corresponding to a certain level of activity (shown by average days of inventory (INV), average days of collection. (AR), cash flow cycle (CCC)) the lower the rate of return on assets. The study also provides additional evidence of the negative effects of economic crisis on the performance of economic groups. The study also shows that the number of short-term asset cycles has a positive impact on operational efficiency, and the level of debt use has a negative impact on operational efficiency. This result implies that the managers of economic groups can increase the efficiency of businesses through a reasonable working capital policy.

• Management Science and Financial Engineering
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• v.11 no.2
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• pp.1-17
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• 2005

In this article we consider a supply chain consisting of a risk-sensitive manufacturer and a riskneutral retailer. The manufacturer maximizes her individual expected profit by designing a supply chain coordinating returns contract (SCRC) that consists of (i) a channel coordinating returns policy that maximizes the supply chain joint expected profit, and (ii) a profit sharing arrangement that gives the retailer an expected profit only slightly higher than that in the no returns case so that it is just enough to induce the retailer to accept the SCRC. Thus, the manufacturer captures as high a percentage as possible of the jointly maximum supply chain profit. However, this contract can sometimes lead to the manufacturer's resulting realized profit being lower than that in the no returns case when demand is lower than expected. In this context, even though profit is sufficiently attractive on average, will the risk-sensitive manufacturer ever consider applying a SCRC? Our research raises this question and focuses on designing a SCRC that can significantly increase the probability of the manufacturer's resulting realized profit being at least higher than that in the no returns case.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 1996.04a
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• pp.477-480
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• 1996

The main objective of this research is to develop the optimal control method for a Distribution Center - multi Branch inventory distribution system. With the continuous review policy, the distribution center places an order for specific order quantity to an outside supplier, and the order quantity is replenished after a certain lead time. Also, each branch places an order for particular order quantity to the distribution center to satisfy the customer demands, and receives the replenishment after a lead time. When an out of stock condition occurs during an order cycle, a backorder is placed to the upper level to fill the unfilled demands. With these situation, variable demand and variable lead time are used for better industrial practice. Futher, actual lead times with a generic lead time distribution are used in developing the control model. Under the actual lead time model, the customer service measures actually attained for the distribution center and each branch are explained as the effective customer service measures. Thus, throughout the optimal control (using computer search procedures), we can set the desired service levels for the distribution center and each branch to produce the effective service level for each branch which is consistent with the goal level of service for each branch. At the same time, the entire distribution system keeps minimum inventories.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.32 no.1
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• pp.117-129
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• 2009

The bullwhip effect is known as the significant factor which causes unnecessary inventory, lost sales or cost increase in supply chains. Therefore, the causes of the bullwhip effect must be examined and removed. In this paper, we develop two analytical tools for the bullwhip effect control in supply chains. First, we develop the quantitative models for computing the bullwhip effect in a three-stage supply chain consisted of a single retailer, a single distributor and a single manufacturer when the fixed-interval replenishment policy is applied at each stage. The quantitative models are developed under the different conditions for the demand forecasting and share of customer demand information. They are validated through the computational experiments. Second, we develop a simulation-based decision support system for the bullwhip effect control in a more diverse dynamic supply chain environment. The system includes a what-if analysis function to examine the effects of varying input parameters such as operating policies and costs on the bullwhip effect.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.1
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• pp.32-41
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• 2008

This paper studies a joint EOQ and EPQ model in which a stationary demand can be satisfied by recycled products as well as newly purchased products. The model assumes that a fixed quantity of the used products are collected from customers and later recovered for reuse. The recovered products are regarded as perfectly new ones. We also assume that the number of orders for newly purchasing items and the number of recovery setups in a cycle can be mutually independent integers. Under these assumptions, we develop an optimization model obtaining the economic order quantity for newly procured products, the optimal lot size for the recovery process, and the sequence of the orders and the setups, simultaneously. And then a simple solution procedure to find a local optimal control parameter set is proposed. To validate the model and the solution procedure, finally, some computational experiments are presented.

• Journal of Korean Institute of Industrial Engineers
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• v.39 no.5
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• pp.440-449
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• 2013

We consider a reverse supply chain with a production facility and a recovery facility, and address the joint control of production and disposal decisions for sustainable operations. Demands are satisfied from on-hand inventory of serviceable products, replenished via manufacturing or remanufacturing. Sold products may be returned after usage and each returned product is disposed of or accepted for recovery. Accepted returned products are converted into serviceable products after remanufacturing process. Formulating the model as a Markov decision process, we characterized the structure of the optimal production and disposal policy as two monotone switching curves under a special condition. Three types of heuristic policies are presented and their performance is numerically compared.

• IE interfaces
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• v.11 no.1
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• pp.55-66
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• 1998

Fleet sizing and distribution of empty equipments are two of the most critical problems in managing transportation system. This paper develops a cost model for sizing a fleet and establishing decentralized redistribution polices of empty equipments by building from inventory theory of multi-echelon system in hub-and-spoke network. An analytical approach to determine control variables of redistribution policies in each terminal and fleet size of the transportation system is proposed and its results are validated by simulation model. Numerical experiments are conducted with respect to parameters of the model and test results for assumptions of the model are discussed.