• 한국경영과학회지
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• 제8권2호
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• pp.9-25
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• 1983

A new approach to cross impact analysis using probabilistic system dynamics(PSD) is presented in this article. The previous models using PSD consist of system dynamics models as a basis which are interacting with cross impact analysis (CIA) sectors. In this model, the policy impact analysis part is separated from the CIA sectors and is constituted an independent subsectors of the model. The policy subsector is designed to separate the policy impact and provide feedback both to the system dynamics base model and cross impact analysis sectors. The new technique is applied to the forecasting, assessment and policy formulation of air pollution in Seoul metropolitan area in 2,000. The results show that the new tool consider policy effects more effectively than the previous PSD models.

• Nuclear Engineering and Technology
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• 제36권1호
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• pp.64-72
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• 2004

The purpose of this study is to develop a system dynamics model for the assessment of the organizational and human factors in a nuclear power plant which contribute to nuclear safety. Previous studies can be classified into two major approaches. One is the engineering approach using tools such as ergonomics and Probability Safety Assessment (PSA). The other is the socio-psychology approach. Both have contributed to find organizational and human factors and to present guidelines to lessen human error in plants. However, since these approaches assume that the relationship among factors is independent they do not explain the interactions among the factors or variables in Nuclear Power Plants. To overcome these restrictions, a system dynamics model, which can show cause and effect relationships among factors and quantify the organizational and human factors, has been developed. Handling variables such as the degree of leadership, the number of employees, and workload in each department, users can simulate various situations in nuclear power plant organization. Through simulation, users can get insights to improve safety in plants and to find managerial tools in both organizational and human factors.

• 한국시스템다이내믹스학회:학술대회논문집
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• 한국시스템다이내믹스학회 2000년도 하계학술대회발표논문집
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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.

• 한국시스템다이내믹스연구
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• 제1권2호
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• pp.5-31
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• 2000

The summit meeting of the South North Korean leaders was a turning point in the relationships between the two countries. It was followed by the Red-Cross Meeting, Minister-Level Meeting, economic agreements, which have increased the relationship more colorful in both quantities and qualities. However, the half-century period for separation was too long to overcome all the problems by only one event. The two countries have quite different social systems; one politically strong person is governing the North, while many interest groups are involved in political decision making processes in the South. In short, it would take a long time to settle down all the problems residing between the two countries. A system dynamics model is developed to describe the long term dynamics of the relations between the South and North Koreas. As a first attempt, the model focuses only on the diplomatic meeting issues between the South and North. The model aggregates diplomatic issues into 5 categories; economic issues, security issues, infrastructure, cultural issues, and past problems. It assumes that there would not be any dramatic changes between the two countries. It is a conceptual model composed of around 200 variables, and should not be used as a forecast tool. However, it captures most of the logics discussed in the papers and conferences concerning the South and North Korea relations. Many sensitivity studies and Monte Carlo simulations have shown that the simulation results matches with mental models of experts; that is the model can be used as a learning tool or as a secondary opinion until the data required by the model is collected. In order to analyze the current situation, five scenarios are simulated and analyzed; the functional approach, the conditional approach, the balanced approach, the circumstantial approach, and the strategic approach. The functional approach represents that the South makes efforts in the area where the possibility of agreement is high for the next 10 years. The conditional approach is a scenario where the South impose all difficult issues as conditions for resolving other diplomatic issues. The balanced approach is resolving the five issues with the same priorities, while the circumstantial approach is resolving issues which seem to be resolved easily. Finally, another optimum approach has been seek using the system dynamics model developed. The optimum strategy (it is named as the strategic approach) was strikingly different from other four approaches. The optimum strategy is so complicated that no one could find it with mental model(or by just insights). Considering that the system dynamic model used to find the optimum is a simplifind (maybe over simplified) version of the reality, it is concluded that a well designed system dynamics model would be of great help to resolving the complicated diplomatic problems in any kind.

• 한국시스템다이내믹스학회:학술대회논문집
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• 한국시스템다이내믹스학회 2002년도 추계학술대회발표논문집
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• pp.59-100
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• 2002

본 연구는 공여 된 신지가 기업회생에 어떠한 영향을 미치고 어떠한 역할을 하는지 시스템 다이내믹스 모형 개발과 시뮬레이션을 통해서 검증한다. 국내 기업회생 사례연구를 통해서 어떻게 조직시스템이 공여 된 신지에 반응을 하는지를 알아보고 공여 된 신뢰와 기업회생에 관한 관계를 수리적으로 모형 화한다. 그리고 공여 된 신지가 어떻게 조직시스템을 위기의 상황에서 다시 회생하도록 움직이는지 알아보기 위해서 시스템 다이내믹스 모형을 개발한다. 모형은 '문제의 발생-해결' 의 관점에서 구축하였고, 공여 된 신뢰에 대한 선행이론으로 귀인이론, 위지 커뮤니케이션을 통한 위기공유를 도출하였다. 본 연구는 시뮬레이션 결과를 통해 공여 된 신지가 기업회생의 새로운 조건이라는 사실을 검증함으로써 기업회생의 동태적 과정에 대한 이론적 통찰과 실무적 시사점을 제공한다.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2008년도 추계학술대회논문집
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• pp.668-669
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• 2008

In this paper, we introduce various coarse-grained elastic network modeling (ENM) techniques as a novel computational method for simulating atomic scale dynamics in macromolecules including DNA, RNA, protein, and polymer. In ENM, a system is modeled as a spring network among representative atoms in which each linear elastic spring is well designed to replace both bonded and nonbonded interactions among atoms in the sense of quantum mechanics. Based on this simplified system, a harmonic Hookean potential is defined and used for not only calculating intrinsic vibration modes of a given system, but also predicting its anharmonic conformational change, both of which are strongly related with its functional features. Various nano and bio applications of ENM such as fracture mechanics of nanocomposite and protein dynamics show that ENM is one of promising tools for simulating atomic scale dynamics in a more effective and efficient way comparing to the traditional molecular dynamics simulation.

• International Journal of Automotive Technology
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• 제7권1호
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• pp.25-34
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• 2006

For decades, simulation technique has been well validated in areas such as computer and communication systems. Recently, the technique has been much used in the area of transportation and traffic forecasting. Several methods have been proposed for investigating complex traffic flows. However, the dynamics of vehicles and diversities of driver characteristics have never been considered sufficiently in these methods, although they are considered important factors in traffic flow analysis. In this paper, we propose a traffic simulation tool called Multi-Agent for Traffic Simulation with Vehicle Dynamics Model (MATDYMO). Road transport consultants, traffic engineers and urban traffic control center managers are expected to use MATDYMO to efficiently simulate traffic flow. MATDYMO has four sub systems: the road management system, the vehicle motion control system, the driver management system, and the integration control system. The road management system simulates traffic flow for various traffic environments (e.g., multi-lane roads, nodes, virtual lanes, and signals); the vehicle motion control system constructs the vehicle agent by using various vehicle dynamic models; the driver management system constructs the driver agent capable of having different driving styles; and lastly, the integrated control system regulates the MATDYMO as a whole and observes the agents running in the system. The vehicle motion control system and driver management system are described in the companion paper. An interrupted and uninterrupted flow model were simulated, and the simulation results were verified by comparing them with the results from a commercial software, TRANSYT-7F. The simulation result of the uninterrupted flow model showed that the driver agent displayed human-like behavior ranging from slow and careful driving to fast and aggressive driving. The simulation of the interrupted flow model was implemented as two cases. The first case analyzed traffic flow as the traffic signals changed at different intervals and as the turning traffic volume changed. Second case analyzed the traffic flow as the traffic signals changed at different intervals and as the road length changed. The simulation results of the interrupted flow model showed that the close relationship between traffic state change and traffic signal interval.

• 한국시스템다이내믹스학회:학술대회논문집
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• 한국시스템다이내믹스학회 2007년도 추계학술대회 발표논문집
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• pp.17-31
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• 2007

• 한국시스템다이내믹스연구
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• 제5권2호
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• pp.89-123
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• 2004

Using materials recovered from the waste stream instead of virgin resources as a raw material in manufacturing has great environmental and economic benefits. However, there is lack of public interest in needs for integrated waste management and its relevant facilities, because of NIMBY syndrome, This article has proposed a system dynamics model for the study of the potential and systemic consequences of resource circulation management system(RCMS) policy for a Sudokwon landfill site in Korea. The results of the study indicate that the effects of RCMS are seen continuously to increase in term with both the community welfare level and the resource and energy level. Moreover the effects of RCMS appear sharply in the first half of the simulation period.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2000년도 제15차 학술회의논문집
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• pp.138-138
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• 2000

In this paper, a methodology for designing a controller based on inverse dynamics for speed control of DC motors is presented. The proposed controller consists of a prefilter, the inverse dynamic model of a system and a fuzzy logic controller. The prefilter prevents high frequency effects from the inverse dynamic model. The model of the system is characterized by a nonlinear equation with coulomb friction. The fuzzy logic controller regulates the error between the set-point and the system output which may be caused by disturbances and it simultaneously traces the change o( the reference input. The parameters of the model are estimated by a genetic a]gorithm. An experimental work on a DC motor system is carried out to illustrate the performance of the proposed controller