• Korean System Dynamics Review
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• v.10 no.1
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• pp.61-76
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• 2009

We try to use system dynamics to forecast the demand/supply and price, also transportation fare for iron ore. Iron ore is very important mineral resource for industrial production. The structure for this system dynamics shows non-linear pattern and we anticipated the system dynamic method will catch this non-linear reality better than the regression analysis. Our model is calibrated and tested for the past 6 year monthly data (2003-2008) and used for next 6 year monthly data(2008-2013) forecasting. The test results show that our system dynamics approach fits the real data with higher accuracy than the regression one. And we have run the simulations for scenarios made by possible future changes in demand or supply and fare related variables. This simulations imply some meaningful price and fare change patterns.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.35 no.2
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• pp.113-123
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• 2012

In this paper, it is examined how the amount of review time per applicant to a college admission officer system is connected with the performance of the selected students after they enter the college. About five years ago, college admission officers system has been introduced to Korea as a government policy. Thus, for most Korean college, there is not enough number of admission officers, while it takes substantial time to find out whether an applicant has potential ability or not. Thus, it is required to find out some policy alternatives to solve this discrepancy. In this paper, a simulation model is built using System Dynamics theory and simulated to understand the relation between the amount of review time and the performance of the selected students. Finally, some implications and policy suggestions are derived from the simulation results.

• Korean System Dynamics Review
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• v.8 no.2
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• pp.209-234
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• 2007

Recently, balanced scorecard is widely used in the public sector as well as in the private sector. Balanced scorecard system of a particular hospital is a very useful tool in the sense that it shows various measures for the management including the traditional financial measures. However, since it does not show the impact of action items, managers have to analyze his potential decisions. On the other hand, a system dynamics model for the management of a hospital can be used to predict future management status. In this paper, a balanced scorecard system with a system dynamics model is developed for a small sized hospital, and the feasibility and applicability of the system have been tested. It turns out the combination of the balanced scorecard and system dynamics technique can be comprised each other. The balanced scorecard system can take advantage of the data forecasted by the system dynamics model including the implementation of action items taken today. On the other hand, the key performance indicators and action items from the balanced scorecard system provide guidelines the scope and direction of the system dynamics model. The additional efforts of developing a system dynamics model are well compensated by the additional colorful functionalities of the system. This paper also covers the future research areas for the combined system to be more effectively developed.

• Korean System Dynamics Review
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• v.6 no.1
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• pp.17-32
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• 2005

An agricultural commodity production cycle model consisting of corn, beef, and dairy sectors was constructed for the purpose of exploring the propagating effects of large-scale disruptive events. In an initial proof-of-concept exercise, we considered an agricultural disruption scenario in which foot-and-mouth disease (FMD) is introduced into the U.S., causing a large-scale outbreak of the disease in both beef and dairy cattle. The magnitude of disruption to the beef and dairy sectors are presented under the existing W response policy and then improvements under two alternative policies are shown.

• Korean System Dynamics Review
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• v.7 no.2
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• pp.21-34
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• 2006

Korean Government has carried out various support policies for small and midium size enterprises(SMEs). However, effect of the policy might not be realized in short term or the policy has turned out in fail. We found out the time of support is also important. Thus we propose that government should figure out the proper time to support funds according to the companies status(Technology, Production, Marketing) based on System Thinking.

• Korean System Dynamics Review
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• v.12 no.3
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• pp.25-46
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• 2011

Recently, performance auditing system of governmen is carried out as most promising framework of government audit. Performance audit by the Board of Audit and Inspection of Korea involves assessing the causes and effects of government policies, programs, and Institutions with the criteria of economy, efficiency, effectiveness. Performance auditing will contribute to strengthening the values of objective assessments of whether public resources are responsibly and effectively managed to achieve intended results. Nevertheless, there seems to be a problems appears in implementation of audit. That is the problems of tendency return to legitimacy audit which is result from the lack of strong approach and methodology. So, this study purpose to developing stronger audit concepts and methods that add to the process and framework of traditional performance auditing system. First, this study evaluates the limitation of current performance auditing system with the perspective of systems thinking. Second, this study analyzes the process and method of current system and develop the conceptual model of the Dynamics Audit System using the system dynamics methodology, which focused on the appropriate auditing process and framework.

• Korean System Dynamics Review
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• v.8 no.2
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• pp.115-140
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• 2007

Changes in material use, energy use and emissions profiles of steel industry are the result of complex interrelationships among a multitude of technological and economic drivers. To better understand and guide such changes requires that attention is paid to the time-varying consequences that technology and economic influences have on an industry's choice of inputs and its associated outputs. We briefly review the range of policy issues in our paper and assess the impact that climate-change policies may have on energy use and carbon emissions in Korea steel industry. We then present the models of Korea steel industry's energy and product flow regarding environmental regulations by using system dynamics simulation methodology(SD). Time series data and engineering information are combined to endogenously specify changes in technologies, fuel mix, and production processes within dynamic simulation model. Through a various scenario, ramifications that the convention of climate change would to steel industry is analyzed, and based on the study results, strategies against environment changes is contemplated in various perspectives to contribute to minimize the risks concerning the uncertain future and to be conducive to Korea steel industry's sustainable development.

• Korean System Dynamics Review
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• v.9 no.1
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• pp.155-170
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• 2008

The purpose of this study was to develop a system dynamics model for management of glucose metabolism disorders that demonstrated dynamic relationships between insulin and plasma glucose levels over the time. The model was developed to 1) represent the physiology of glucose metabolism for an normal adult subject, 2) to draw causal loop diagram that demonstrate feedback systems of glucose regulation in normal condition and pathologic condition of the type 2 diabetes, 3) to develop an interactive computer simulation model for management of glucose metabolism disorders. The simulation results showed the plasma glucose level for normal persons varied from 75 to 140 which was consistent with clinical findings. As an example for patients we selected a case which varied from 110 to 310. Two types of interventions were chosen to review the model; meal control and insulin administration. The simulation results for those cases also matched well with clinical findings. The developed model can be used as an effective educational tool for patients to develop healthy lifestyle choices. The results also provide a blueprint for health providers to maintain normal blood glucose levels in diabetes patients.

• Korean System Dynamics Review
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• v.8 no.1
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• pp.5-24
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• 2007

This study explores the partnership between government and human service nonprofits in the United States from the perspective of resource dependence theory and extends the theory with system dynamics in order to better explain government-nonprofit service delivery. The article is structured as follows. First, I introduce the historical development of the government-nonprofit partnership in service delivery in the United States. Second, I present an overview of resource dependence theory for government-nonprofit service delivery, including assumptions, key elements, claims, how well it explains the government-nonprofit service delivery, and limitations. Third, I highlight the advantages of system dynamics along with the limitations of resource dependence theory, as an attempt to revise the theory. Finally, I conclude with a summary and suggestions for the next steps in theoretical development and research.

• Korean System Dynamics Review
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• v.8 no.1
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• pp.117-149
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• 2007

This paper aims to analyse the impact of city-county consolidation on promotion practices of local government employees, using system dynamics approach. The cases employed in this study are Cheongju City and Cheongwon County which reached the referendum stage twice but without success. While the idea of consolidating two neighbouring local governments via a merger sounds enticing, some opponents argue that consolidation may cause some problems on the part of local government employees, emphasizing that consolidation could lengthen actual time period needed for local government employees' promotion. The majority of the existing literature on city-county consolidation, however, tends to describe the most successful cases, focusing on the achievements it has made or the political processes associated with it. With this in mind, this paper attempts to identify the impacts of consolidation on the local government employees' promotion time period, utilizing system dynamics approach. It concludes that consolidation could rather shorten the time period of promotion of local government employees concerned from the long term perspective.