• Korean System Dynamics Review
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• v.3 no.1
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• pp.79-104
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• 2002

A system dynamics project is going on for forecasting automobile market in Korea. The project is made up of three stages, and the first stage has been wrapped up. As the first attempt, most efforts have been focused on the sound foundation rather than the exact forecast. The model consists of three sectors; the supply sector, the demand sector, and the population sector. The supply sector is a simple stock and flow diagrams representing the supply capacities of all automobile types. The major effort is made on the demand sector and the population sector. The demands are divided into three categories; replacement demands, new demands, and additional demands. The model applies “one car per person" concept, and assumes there will be no additional demands for a while. The replacement demands are calculated based on a simple stock and flow diagram. The new demands are calculated via Bass models; each bass model represents a diffusion for each age group. The population is divided into 101 age groups (age 0 to age 100). The model has been calibrated with past 10 year data (1990 - 1999), and tested for the next two years (2000-2001). The results ware acceptable, although a fine tuning is required. Now the second stage is going on, and most of efforts are made how to incorporate the economic and cultural factors.

• Korean System Dynamics Review
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• v.17 no.2
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• pp.5-32
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• 2016

Purpose of this paper is to review series of Limits to Growth studies from its original Rome Club Report published in 1972 to the most recent one in 2012 by Jorgen Randers and finds its implications on concept and strategy of sustainable development. For this purpose first, this paper reviewed series of Limits to Growth studies in details with focus on scenarios used in simulation of world model. Second, response to the original Limit to Growth was reviewed and to see validity of its scenario based simulations, simulated results of interest variables and actual historical data up to the year 2010 was compared. Third, structure and key arguments in both studies, Limit to Growth studies and Our Common Future was explained and compared. Finally, implications of the Limit to Growth studies on concept and strategy for sustainable development was discussed. Based on the comparison, this paper argued that even if the term sustainable development was not used in the Limit to Growth at all, concept and strategies for sustainable development implied in the Limit to Growth are more clear and specific than those of Our Common Future. Since Limit to Growth studies were simulation based ones that produce detailed behaviors on interest variables, it clarifies more clearly the abstract concept of sustainable development and thus, provides specific guidelines for the direction of sustainable policy which has been suffering long from vagueness of concept of sustainable development.

• Korean System Dynamics Review
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• v.7 no.1
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• pp.5-26
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• 2006

Ever increasing dependence of organization on information technology stimulates interactions between individuals and groups in the process of knowledge creation, which overall impies that a reciprocal mechanism lies within the structure of the growth of group intelligence. Individual's intelligence may affect the group intelligence, and vise versa. However, the level of group intelligence is not necessarily determined by the sum of individual's intelligence but the quality of the interactions among the individuals. This study thus aims to conceptually identify the dynamic structure of interactions among the factors influencing the group intelligence level, which is believed to be used as a tool to measure the difference of intelligence between groups. To achieve this goal several attempts were made. First, determinants of intelligence at indiviual level and group level and similarities and differences between individual's and group intelligence were identified from the previous research. Second, causal loop diagrams were developed, which show how individual's intelligence influences group intelligence and vise versa. Third, it was attempted to identify and interpret which feedback loops are most influential in either improving or hapering group intelligence as a whole. Since this study remains only at exploratory level, a more detailed and workable model for field applications has to be developed in the future.

• Journal of Advanced Technology Convergence
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• v.2 no.3
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• pp.59-66
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• 2023

The most important thing in digital transformation is SW technology. However, many companies are having difficulty securing SW technology and manpower. In particular, it is reported that the shortage of SW manpower will increase further. The government is carrying out manpower training policies and many support projects to resolve SW manpower supply and demand policies, but accurate predictions of demand and supply of the software industry are essential for these policies to be effectively established. Therefore, this study developed a simulation using a system dynamics methodology that can perform dynamic structural analysis to resolve the supply and demand imbalance in the software industry. System dynamics is appropriate to find the cause and policy alternatives from a dynamic perspective on the imbalance in manpower supply and demand in the software industry. In detail, the U.S. Bureau of Labor Statistics (BLS) methodology was used to develop a prediction model for manpower demand and supply in the software industry, and scenario analysis was performed to derive policy implications.

• Journal of Korea Port Economic Association
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• v.33 no.1
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• pp.75-87
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• 2017

The purpose of this study is to utilize the system dynamics to carry out a medium and long-term forecasting analysis of the bunker price. In order to secure accurate bunker price forecast, a quantitative analysis was established based on the casual loop diagram between various variables that affects bunker price. Based on various configuration variables such as crude oil price which affects crude oil consumption & production, GDP and exchange rate which influences economic changes and freight rate which is decided by supply and demand in shipping and logistic market were used in accordance with System Dynamics to forecast bunker price and then objectivity was verified through MAPEs. Based on the result of this study, bunker price is expected to rise until 2029 compared to 2016 but it will not be near the surge sighted in 2012. This study holds value in two ways. First, it supports shipping companies to efficiently manage its fleet, offering comprehensive bunker price risk management by presenting structural relationship between various variables affecting bunker price. Second, rational result derived from bunker price forecast by utilizing dynamic casual loop between various variables.

• Journal of the Korea Society for Simulation
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• v.27 no.3
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• pp.53-63
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• 2018

Since warfare surroundings getting complex and diverse in the future, it is not simple to make appropriate structures and organizations for military groups along the phenomenon. Therefore, this study proposes a methodology of verification for army staff's structure and organization by units in the future using System Dynamics(SD). The procedure of using SD for the verification is a calculation of database(DB), the design of causal loop diagram, and the simulation and analysis. First, DB such as individuals' workload and time is calculated through observation after a real group of staff. Second, the causal loop diagram is considered by a flow of task, and it is modeled. Third, the DB is entered into the model and simulated for analyzing of appropriacy. This study used Powersim program for designing the SD model. One of the weaknesses of the methodology of this study is possibilities of a different result by the DB by observers and perspectives by analysts. As supplementation for the weakness, this study includes research analysis and surveys for the total analysis. The meaning of this study is that it suggests a methodology of warfighting experimentation to analyze structure and organization of military groups with quantifying suitability in the scientific method.

• Journal of Digital Convergence
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• v.19 no.1
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• pp.67-75
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• 2021

Despite the increase in sales of imported vehicles in Korea, research on the sales forecast of parts logistics centers is very limited. This study aims to perform a sales prediction on bestselling goods in the automobile part logistics center. System dynamics was adopted as a methodology for the prediction method, which considered causal relationship of variables that affected the dynamic characteristics and feedback loops. The analysis results showed that the consumable sales amount of oil increased over time. As a result of conducting the MAPE, the model was assessed to be a reasonable predictive model of 31.3%. In addition, the sales of battery products increased from every October in both of actual and predicted data followed by the peak sales in December and then decrease from next February. This study has academic implications that it secured actual data of specific imported automobile part logistics center, which has not done before in previous studies and quantitatively analyzed the prediction of the quantity of released goods of future sales through system dynamics.

• Korean System Dynamics Review
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• v.7 no.1
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• pp.67-90
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• 2006

A series of system dynamics model was developed for forecasting demand and supply of human resource in the electricity industry. To forecast demand of human resource in the electric power industry, BLS (Bureau of Labor Statistics) methodology was used. To forecast supply of human resource in the electric power industry, forecasting on the population of our country and the number of students in the department of electrical engineering were performed. After performing computer simulation with developed system dynamics model, it is discovered that the shortage of human resource in the electric power industry will be 3,000 persons per year from 2006 to 2015, and more than a double of current budget is required to overcome this shortage of human resource.

• Journal of Korean Society of Water and Wastewater
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• v.28 no.6
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• pp.755-763
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• 2014

In this paper, a System Dynamics(SD) computer simulation model has been developed to assess the effects of developing and providing an alternate water source. A water service index was also developed to estimate the level of overall customer satisfaction on water supply service. Data from the Busan water supply service and the Korea Development Institute regarding the Nak Dong river bank storage development were utilized during the modeling processes. Some important indicators of the system under study were analyzed by the simulations of development of the alternate water source for Busan. The developed SD model and the water service index can be further utilized as a tool that can assess the extent and timing of an additional service improvement project.

• Korean Journal of Construction Engineering and Management
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• v.17 no.1
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• pp.28-39
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• 2016

Since 2002, Korea Government has introduced Green Standard for Energy and Environmental Design Certification for reducing GHG emission in building area. However, total number of G-SEED Certification is only around 1% of total number of approved apartment buildings despite the various boosting policies. In this situation, most boosting policies and policy improvement researches are leaning toward the supplier's aspect. However, comprehensive relation and dynamics between consumer and supplier has to be considered because housing market is operated by market participants' mutual interaction. Therefore, this research presents system dynamics models based on decision making analysis of consumer and supplier in G-SEED Certification apartment building market. Then, this research evaluate the validity of boosting policies using the model. The proposed analysis can assist government to make next G-SEED Certification boosting policy.