• Korean System Dynamics Review
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• v.7 no.2
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• pp.97-120
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• 2006

This paper deals with the extension of and discussion on the System Dynamics model (Jeong & Jeon, 2005) of river crabs in Korea. The previous model has been elaborated to empirically search for the optimal restoration and harvest rates of crabs in the Imjin River, on the basis of theoretical models of population dynamics in the field of bio-mathematics and environmental economics. In this paper, the authors tries to couple a series of new feedback loops related to density restrictions and cannibalistic behaviors with a stage-structured model of the crab ecosystem, and also to endogenize the parameter of baby crabs' survival that is caused by water quality improvement and income increase. Through these extensions and relaxations, the authors are able to argue about the strategic decision of the optimal rates additional considerations as well as the properties of the integrated system that was not covered in the previous paper.

• Korean System Dynamics Review
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• v.3 no.1
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• pp.43-60
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• 2002

This paper describes the forecast of wholesale price in competitive Korean electricity market using the system dynamics approach. The system dynamics concepts have been implemented with the Ithink software. This software facilitates the development of stock and flow model with information feedback. Using this model, the future wholesale electricity price can be computed hour by hour, quarterly, and yearly. This model also gives the energy planner the opportunity to create different scenarios for the future of deregulated wholesale markets in Korea. Also It will lead to increased understanding of competitive wholesale market as a complex, dynamic system. Research results show that the plant construction appeared in waves of boom and bust in Korean electricity market like real estate construction. That is, the Korea wholesale market's new power plants and the market price will appear the Boom and Bust cycle. It is very similar behavior as real estate industry. In case of consideration of DSM program, The DSM savings lead to a somewhat different timing of the booms in construction and of price spikes. But the DSM programs do not eliminated the fundamental dynamics of the boom and bust. And the wholesale price is maintained at the lower level compared to the case of without DSM program. However, the unexpected result is found that due to the lower market price, Investor make significantly less investment in new CCs, which leads to the higher wholesale price after 2010. It suggests that the DSM Policy must be implemented with the dynamics of competitive Electricity Market.

• Journal of KSNVE
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• v.10 no.1
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• pp.117-122
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• 2000

The dynamics of train has recently been analysed in many cases and very complex nonlinear creep theories have been developed by many engineers. But much calculation time is spent and latest complex creep theories cannot be adapted in train analysis. In this study efficient and fast train analysis method was suggested. Many of degree of freedom were reduced in multi-vehicle system using equivalent system and fast calculation time was achieved. And the accuracy of equivalent system method was proved by linear and nonlinear dynamic analysis.

• Journal of The Korean Society of Agricultural Engineers
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• v.56 no.6
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• pp.45-53
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• 2014

This study presents a system dynamics modeling approach to simulate daily streamflow in a watershed including wastewater treatment plant which contributes to irrigation water supply. The conceptual system dynamics model considering the complex and dynamic hydrological processes in the watershed was developed. The model was calibrated and validated each for two years based on observed flow data. Model performances in terms of $E_{NS}$, RSR, PBIAS, and $R^2$ were 0.64, 0.60, -3.6 %, and 0.64 for calibration period, and 0.66, 0.58, -2.6 %, and 0.66 for validation period, respectively, showing an applicability on generating the daily streamflow. System dynamics modeling approach could help better understand the hydrological behavior of the watershed being reused wastewater for agriculture, by providing graphical dynamics of the hydrological processes as well as conventional rainfall-runoff model results.

• Korean System Dynamics Review
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• v.11 no.1
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• pp.59-83
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• 2010

The Korean Government decided to reduce 30% of carbon emissions as of 2020, tightening regulations to reduce greenhouse gas in the international society. Therefore it will burden Korean logistics industry that overland trucking freight covers 70~80% of all, to lower emissions. As known, rail and coast(feeder) transport systems can be substituted for road transport but there are many problems to solve in Korean multimodal (intermodal) transport system such as time, cost, etc. Because of this, multimodal transport system should be improved systematically. For the reason, it aims to study a conceptual model with Thinking Process of TOC(theory of constraints) and System Dynamics to help improve the existing multimodal transport system for green logistics.

• Proceedings of the Korean System Dynamics Society
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• 2000.07a
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• pp.29-45
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• 2000

The purpose of this paper is understanding the dynamics of knowledge based industries in Korea and suggesting policy recommendations for supporting those industries. Following KIETs (1999) definition of knowledge intensity, this paper classified industries in Kyung Ki Province according to several knowledge indicators including R＆D activity and human capital content. Having classified industries, this paper investigates growth dynamics of knowledge based industries in Kyung-Ki Province. Based on surveys on some 280 knowledge based industries in Kyung-Ki province, growth path of those industries were identified using path analysis. Using the growth path and coefficient identified by the analysis, system dynamics model was build to simulate dynamics of knowledge based industries in Kyung-Ki province. With the model, further analysis was made to investigate some policy measures that can promote knowledge based industries.

• Korean System Dynamics Review
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• v.13 no.1
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• pp.41-62
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• 2012

The purpose of this study is to examine Korea's social conflict structure from System Dynamics perspective and to suggest policy direction for conflict resolution. Unlike previous studies on Korea's social conflict, this study tries to find out core structure of Korea's social conflict with help of studies on system archetypes. As a result, Korea's social conflict structure was analyzed as a combined prototype of 'limit to the growth' archetype and 'success to the successful' archetype. Based on this combined system archetype, a simple conflict model was simulated to examine the magnitude of conflict and success that could be reached under different conditions. With simulation results, policy suggestions were made for conflict resolution.

• Korean System Dynamics Review
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• v.2 no.2
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• pp.41-62
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• 2001

Perhaps, one of the typical emerging markets drawing tremendous attention from not only business professionals but also policy-makers would be the mobile Internet services. In recent years many research institutes reported their predictions on the growth of the mobile Internet services market, announcing that the market would show explosive growth and replace the wired Internet service market rapidly. Unfortunately, however, the reality we are facing at present is quite different from their expectations. The realized share of the mobile services in Korea last year has turned out remaining only about one percent of the total network service revenue. What are the reasons for the gap between the prospects and the reality? Starting from this question, this paper attempts to explore the generic pitfalls of the traditional number-crunching methods adopted thus far for the forecast of newly emerging market trends, and present an alternative by introducing systems thinking to the mobile Internet service market as an example, followed by its rationale as a new tool for forecasting and some reasoning about why traditional methods are no longer appropriate.

• Transactions of the Korean Society of Automotive Engineers
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• v.7 no.9
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• pp.212-219
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• 1999

This paper describes the NANDO VDC (Vehicle Dynamics Control) system for the vehicle stability enhancement and consists of the control strategies , computer simulation and tests on the various road surface. This VDC system controls the dynamic vehicle motion in the emergency situation such as the final oversteer/understeer andallows the vehicle to follow the course as desired by the driver. The system is based on an active yaw control and its performance verified by the test is shown. Also the comparison between the MANDO VDC System and a competitor is carried out.

• Korean System Dynamics Review
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• v.4 no.2
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• pp.71-94
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• 2003

The purpose of this dissertation is to build a development density control model and estimate optimum developmental density level for a sustainable urban growth management. To develop the model, system dynamics modeling approach was used. The model was developed to analyze how urban growth, transition, and decay occur depending on the interaction among population, houses, industry structure, land and urban infrastructure such as road, water supply, and sewage treatment facilities. The model was applied to Anyang city to estimate optimum density level. Extensive computer simulation was conducted to find out the maximum numbers of population, industry structure, houses, and cars that can be adequately sustained with the current Anyang city's infrastructure capacity. The computer simulation result shows that the city is overpopulated by some 90,000 people. It nab analyzed that 20％ increase of existing capacity of urban infrastructure is necessary to support current population of Anyang city. To reduce the population to the adequate level whereby the current urban infrastructure can sustain, the current city regulation on floor area ratio needs be strengthened at least 20％ to 35%.