• Proceedings of the Korean Institute Of Construction Engineering and Management
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• 2006.11a
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• pp.74-79
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• 2006

Generally, policymakers have a tendency to target achieving individual policy goals rarely considering their effects as a whole. In addition, the conventional policymaking practice lacks considerations on the various needs of industry participants and their response to public policies. To address this issue, a system dynamics model as a simulation model-based approach, which can examine the effectiveness of public policies in a systematic manner, is presented with an application example of the Singaporean government's policies to enhance construction productivity. Using this simulation model, the governmental policies are tested in a qualitative manner. Having obtained policy implications from the model structure and simulation results, suggestions and guidelines are provided to make the governmental policies more effective. Finally, based on the research findings it is concluded that the simulation model-based approach could be useful for construction policymaking.

• Journal of Korean Society of Water and Wastewater
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• v.34 no.2
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• pp.105-114
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• 2020

In this study, based on the System Dynamics (SD) methodology, the interrelationship between the factors inherent in the operation of the New Technology Certification System (NTCS) in Korea was identified by a causal map containing a feedback loop mechanism in connection with 'new technology development investment', 'commercialization of new technology', and 'sales by new technology'. This conceptualized causal map was applied to the simulation of the operations of the New Excellent Technology and Environmental Technology Verification System (NET&ETV) run by the Ministry of Environment among various NTCSs in Korea. A SD computer simulation model was developed to analyze and predict the operational performance of the NET&ETV in terms of key performance indices such as 'sales by new technology'. Using this model, we predicted the future operational status the NET&ETV and found a policy leverage that greatly influences the operation of the NET&ETV. Also the sensitivity of the key indicators to changes in the external variables in the model was analyzed to find policy leverage.

• Journal of Technology Innovation
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• v.22 no.3
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• pp.101-133
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• 2014

Climate change and low-carbon consumer movement is demanding proper response around the world while rising oil price increases consumers' needs for green car. As a preliminary study to establish an industrial platform for green car and bring out corporate strategies, this article aims to propose an academic research framework by using various methodologies including conceptual/mathematical modeling, system dynamics, and ABM from different angles. First, an analysis framework for the industrial platform was introduced to analyze green car cases, required elements were proposed, and econometrics was applied to build a basic model related to green platform (two-sided market). Also, to analyze from a dynamic perspective, a system dynamics model was applied to green car environment to build a system dynamics analysis model that is applicable to particular green car industry analysis. Lastly, an agent based model was used to study the way to activate the hybrid car market in Korea from individual consumers' perspective. Based on the result, vehicle policies that are either being enforced or planned to be enforced in the Korean HEV market can be analyzed.

• Proceedings of KOSOMES biannual meeting
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• 2003.11a
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• pp.7-11
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• 2003

Ship is being operated under a highly dynamic environments and many factors are related with ship's collision and those factors are interacting. So, an analysis on the ship's collision causes is very important to prepare countermeasures which will ensure the safe navigation. And the analysis confirmed that ship's collision is occurred most frequently and the cause is closely related with human factor. The main purpose of this study is to build a model of human factors in ship's collision cause using SD(System Dynamics} approach and to measure a effect which is risk control countermeasures of ship's collision. To achieve this aim, the structure analysis on the causes of ship's collision using FSM are performed, and the structure was changed by quantitative, qualitative factors and their feedback loops in casual map. This model was performed over 20 years(1993-2012) in a standard simulation model and 8 policy simulation models.

• Proceedings of KOSOMES biannual meeting
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• 2004.05b
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• pp.29-34
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• 2004

Ship is bring operated under a highly dynamic environments and many factors are related whit marine accident and those factors are interacting. An analysis on the marine accident is very important to prepare countermeasures which will ensure the safe navigation This paper aims to build a model of the rouses and improved policy for marine accident using SD(System Dynamics) approach and to measure a effect which is risk control countermeasures of marine accident The methodology of this paper is to perform the causes and improved policy for marine accident using Brainstorming method, and was to changed by quantitutive, qualitative factors and their feedback loops in casual map. This model was performed over 23 years($1997\~2020$) in a standard simulation model and 4 policy simulation models.

• Korean Journal of Construction Engineering and Management
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• v.20 no.2
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• pp.68-78
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• 2019

Recently, housing prices have surged, and the government has implemented various regulations, such as finance and taxes. Because of the policy, the nationwide housing price have stabilized, but polarization has occurred. Some argue that regulation can adversely affect the actual demand. Therefore, not only the correlation between market variables but also ripple effect of policy has to be analyzed in policy planning and analysis from a microscopic point of view. In this study, a simulation model was developed by integrating system dynamics for analyzing market structure and agent-based model for modeling decision process of market participants. This research applied the financial regulation and the tax regulation to the model and evaluated the policy effectiveness. This study reveals which feedback dominates according to the policies, which have same purpose. It is because market participants make different decision for each policy. Furthermore, there were other ripple effects not only in the policy target submarket but also in other submarket.

• Korean Journal of Construction Engineering and Management
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• v.13 no.1
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• pp.148-159
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• 2012

Recently construction companies' capital condition has been aggravated due to low profit, fierce competition and market contraction. For this reason, the companies rely on public construction projects that protect construction fee by regulations. Despite these regulations, problems regarding progress payment are constantly happening. Also, insufficient analysis on interaction between contractors makes policy making difficult. Thus, in this study, interaction between contractors are quantitatively determined according to delay of application and payment based on current public construction regulations on construction stage. A system dynamics model is used, which analyzes the problems based on an interaction between contractors, and solutions for progress payment application and payment delay are suggested according to the research results.

• Korean Journal of Construction Engineering and Management
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• v.8 no.5
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• pp.119-131
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• 2007

Design build (DB) is a construction project delivery system which has become one of the favored ones and the growth of DB by the public agencies has been steadily increasing. DB can be viewed as an evolutionary project delivery system, since DB project team members collaborate on work with each other, keep seeking cost effective and innovative alternatives that meet the construction needs of the project. Thus DB outperformed others in delivery speed, cost saving, and turnover quality. In Korea, DB projects likewise have steadily increased that it is needed to analyze characteristics of DB delivery system in Korea. For that purpose, this research would offer an analysis of characteristics of DB delivery system in Korea using system dynamics model with investigating the public market trend, comparing DB performance to DBB, and analyzing questionnaire survey.

• Korean System Dynamics Review
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• v.7 no.1
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• pp.119-146
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• 2006

City of Gyeongju's referendum finally offered the long-waited low-level radioactive waste disposal site in November 2005. Gyeongju's positive decision was due to the various economic rewards and incentives the national government promised to the city. 300 million won for an accepting bonus, 8.5 billion won, annual revenue fro the entry quantity of waste into the city's disposal site, the location of the headquarter building of the Korean Hydro and Nuclear Power Co., and the accelerator research center. All of the above will affect the city's infrastructure and the citizens' economic and cultural lives. Population, land use, economic structure, environment and quality of life will be affected. Some will be very positive, and some will be positive. This research project will see the future of the city and forecast the demographic, economic, physical and environmental changes of the city via computer simulation's system dynamics technique. This kind of simulation will help City of Gyeongju's what to prepare for the future. The population forecasting of the year 2026 will be 289,069 with the waste disposal site, and 279,131 without the waste disposal site in Gyeongju. The waste disposal site and the relocation of the company headquarters and location of the accelerator research center will attract 9,938 individuals more with 511 manufacturing shops and 1944 service jobs. The population increase will bring 3,550 more houses constructed in the city. Land use will also be affected. More land will be developed. However, mad, water plant and waste water plant will not be expanded as much. The city's financial structure will be expanded, due to the increased revenues from the waste disposal site, and property tax revenues from the middle-class employees of the company, and the high-powered scientists and technologists from the accelerator research center. All in an, the future of the city will be brighter after operating the nuclear waste disposal site inside the city.

• Journal of Korea Port Economic Association
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• v.31 no.2
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• pp.23-40
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• 2015

This study measures how Korean shipping policies influence the expansion of the country's merchant fleet using system dynamics. It uses various indexes as factors influencing the gross tonnage of the Korean merchant fleet, such as the Baltic Dry Index, Howe Robinson Container Index, China Containerized Freight Index, and Worldscale Index, as well as the US dollar-Korean won exchange rate, world merchant fleet statistics, and the debt ratio of Korean shipping companies. After establishing the simulation model, the mean absolute percentage error is found to be less than 10%, confirming the accuracy of the model. Therefore, a sensitivity analysis is conducted to measure the influence of the selected shipping policies, including the gross tonnage of vessels registered under the Korean second registry system, loans of publicly owned financial institutions to shipping companies, ship investment fund, and the number of shipping companies participating in the tonnage tax scheme. The sensitivity analysis reveals that the influence of vessel tonnage and loans to shipping companies is the most significant, while that of the number of companies participating in the tonnage tax scheme is minimal.