• Korean System Dynamics Review
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• v.3 no.1
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• pp.61-77
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• 2002

This paper reviews issues and methodological status of system dynamics and suggest some research agenda for its development in Korea. After reviewing some characteristics of system dynamics approach, including dynamic feedback perspective and endogenous point of view, the paper pointed out methodological characteristics of system dynamics. It seems to be the most notable characteristics of System Dynamics that it use both quantitative and qualitative approach in explaining and modelling reality. Besides, System Dynamicists rely more heavily on refutationism than instrumentalism and this allows System Dynamicists follow more strict way of scientific inquiry. For the development of System Dynamics in Korean academic circle, developing training program and curriculum, networking scattered System Dynamicist all over the country, would be the most important task.

• Korean System Dynamics Review
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• v.8 no.1
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• pp.25-47
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• 2007

This paper executes positive analysis about the thesis of 100 volumes which were published for 2000-2006 years through 'Korean System Dynamics Journal', to grope and to see the academic developments of Korean System Dynamics. The summarized analysis results are same as follows. First, Korean System Dynamics researches appear that quantitative researches are much more than qualitative ones. Second, the researches that aimed to solve problem are relatively much more than theory-oriented ones. Third, System Dynamics researches in the department of social science are more abundant than that of science and engineering. Based on these results, for establishing of Korean System Dynamics identity, we will work hard to study qualitative researches, increase the research domains and elevate the academic statue of System Dynamics.

• Proceedings of the KIEE Conference
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• 2007.04a
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• pp.213-215
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• 2007

This paper introduces an emotional behavior decision model for intelligent service robots. An emotional model should make different behavior decisions according to the purpose of the robots. We propose an emotional behavior decision model which can change the character of emotional model and make different behavior decisions although the situation and environment remain the same. We defined each emotional element such as reactive dynamics, internal dynamics, emotional dynamics, and behavior dynamics by state dynamic equations. The proposed system model is a linear system. If you want to add one external stimulus or behavior, you need to add just one dimensional vector to the matrix of external stimulus or behavior dynamics. The case of removing is same. The change of reactive dynamics, internal dynamics, emotional dynamics, and behavior dynamics also follows the same procedure. We implemented the proposed emotional behavior decision model and verified its performance.

• Bulletin of the Korean Chemical Society
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• v.21 no.4
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• pp.419-424
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• 2000

In this study we have investigated the determination of proper time step in molecular dynamics simulation.Since the molecular dynamics is mathematically related to nonlinear dynamics, the analysis of eigenvalues isused to explain the relationship between the time step and dynamics. The tracings of H2 and CO2 molecular dynamics simulation agrees very well with the analytical solutions. For H2, the time step less than 1.823 fs pro-vides stable dynamics. ForCO2, 3.808 fs might be the maximum time step for proper molecular dynamics. Al-though this results were derived for most simple cases of hydrogen and carbon dioxide, we could quantitatively explain why improperly large time step destroyed the molecular dynamics. From this study we could set the guide line of the proper time step for stable dynamics simulation in molecular modeling software.

• Korean System Dynamics Review
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• v.15 no.3
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• pp.37-59
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• 2014

This paper is to study dynamics of populations of religions. As human population is a crucial source of social dynamics, the religious population is a driving force that changes political and cultural landscape of society. Although many christian scholars have reported important causal factors in changing population of christian world, there are few studies on the dynamics of religious population in system dynamics. This paper interprets these dynamic mechanisms in terms of feedback loops and constructs a basic system dynamic model to forecast future trend of religious population in Korean society.

• Journal of the Korean Physical Society
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• v.73 no.9
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• pp.1385-1392
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• 2018

A network with coupled biological neurons provides various forms of collective synchronous dynamics. Such phase-locking dynamics states resemble eigenvectors in a linear coupling system in that the forms are determined by the symmetry of the coupling strengths. However, the states behave as attractors in a nonlinear dynamics system. We here study the collective synchronous dynamics in a neural system by using a novel theory. We exhibit how the period and the stability of individual phase-locking dynamics states are determined by the characteristics of synaptic couplings. We find that, contrary to common sense, the firing rate of a synchronized state decreases with increasing synaptic coupling strength.

• Proceedings of the Korean System Dynamics Society
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• 2007.06a
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• pp.71-92
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• 2007

This paper executes positive analysis about the thesis of 100 volumes which were published for 2000-2006 years through 'Korean System Dynamics proceeding', to grope and to see the academic developments of Korean System Dynamics. The summarized analysis results are same as follows. First, Korean System Dynamics researches appear that quantitative researches are much more than qualitative ones. Second, the researches that aimed to solve problem are relatively much more than theory-oriented ones. Third, System Dynamics researches in the department of social science are more abundant than that of science and engineering. Based on these results, for establishing of Korean System Dynamics identity, we will work hard to study qualitative researches, increase the research domains and elevate the academic statue of System Dynamics.

• Korean System Dynamics Review
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• v.14 no.1
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• pp.89-104
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• 2013

This study aims to explore the potentials of System Dynamics as a tool to understand the community welfare practice by paying attention to the strengths of System Dynamics to complement the weaknesses of the theories and studies of the community welfare practice. The contents of this study are as follows. First, it draws the limitations of its theories and studies by reviewing the literatures related. Second, it outlines the characteristics of the community welfare practice process as well as the strengths of System Dynamics as a tool to understand the community welfare practice. Third, it presents a causal loop model of System Dynamics applied to the community welfare practice process. Lastly, it concludes with the suggestions and implications of the key research findings. This study is expected to be a basic study to highlight the potentials of System Dynamics as a tool to understand the community welfare practice.

• Journal of Mechanical Science and Technology
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• v.19 no.spc1
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• pp.227-236
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• 2005

Multibody system dynamics is based on classical mechanics and its engineering applications originating from mechanisms, gyroscopes, satellites and robots to biomechanics. Multibody system dynamics is characterized by algorithms or formalisms, respectively, ready for computer implementation. As a result simulation and animation are most convenient. Recent developments in multibody dynamics are identified as elastic or flexible systems, respectively, contact and impact problems, and actively controlled systems. Based on the history and recent activities in multibody dynamics, recursive algorithms are introduced and methods for dynamical analysis are presented. Linear and nonlinear engineering systems are analyzed by matrix methods, nonlinear dynamics approaches and simulation techniques. Applications are shown from low frequency vehicles dynamics including comfort and safety requirements to high frequency structural vibrations generating noise and sound, and from controlled limit cycles of mechanisms to periodic nonlinear oscillations of biped walkers. The fields of application are steadily increasing, in particular as multibody dynamics is considered as the basis of mechatronics.

• Journal of Distribution Science
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• v.16 no.3
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• pp.59-68
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• 2018

Purpose - This study empirically examines the effects of environmental dynamics(dynamics of one's own company, dynamics of competitors, and dynamics of customers), within the franchise industry, on the dependence and conflict(dysfunctional conflict and functional conflicts) and the business performances(financial and non-financial). Furthermore, we empirically examined the effects of the dependence of franchise on the conflicts(dysfunctional conflict and functional conflict) and business performances(financial and non-financial). Finally, we empirically examined the effects of the conflicts of franchise (dysfunctional conflict and functional conflict) on the business performances(financial and non-financial). Research design, data, and methodology - Our study conducted a survey on the managers and owners of the franchises located in Seoul, Gyeonggi, and Incheon. The total number of valid samples was 230, and the structural equation model was analyzed by using AMOS program. Results - First, the environmental dynamics(dynamics of one's own company, dynamics of competitors, and dynamics of customers) in the franchise industry were shown to have statistically significant positive effect on the dependence of franchise. Second, among the environmental dynamics in the franchise industry, the dynamics of one's own company and the dynamics of the customers were shown to have a statistically significant positive effect on the dysfunctional conflicts of franchisees. However, in the franchise industry, the dynamics of competitors did not have a statistically significant effect on the dysfunctional conflict of the franchise. Third, in the franchise industry, the environmental dynamics(dynamics of one's own company, dynamics of competitors, and dynamics of customers) did not have a statistically significant effect on the functional conflicts of the franchises. Fourth, the dependence of franchise was shown to have a statistically significant positive effect on the conflicts(dysfunctional conflict and functional conflict). Fifth, the dysfunctional conflict of franchisees was shown to have a statistically significant negative effect on the business performances(financial and non-financial). Sixth, the functional conflicts of franchises was shown to have a statistically significant positive effect on business performances(financial and non-financial). Conclusions - From the franchise industry researches, the environmental dynamics were selected as the preceding factors and the relationship leading to dependence, conflict, and business performance were constructed into model.