• Proceedings of the KSRS Conference
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• v.2
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• pp.533-533
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• 2006

• Proceedings of the KSRS Conference
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• v.1
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• pp.51-51
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• 2006

• Journal of Environmental Science International
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• v.26 no.10
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• pp.1185-1200
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• 2017

Solid waste management is currently a topic of concern, particularly in the protection of humans and the environment from toxic pollutants and hazardous materials. The importance of solid waste management is recognized at international, national, and community levels. Different agendas have been prioritized and assigned to improve quality of life, productivity, and health, and reduce the burden of pollution. Suitable management of solid waste requires appropriate technology that is affordable, socially accepted, and environmentally friendly. The use of a smart management system involving system dynamics can save energy, money, and labor. System dynamics is a computer-based approach that aids in predicting the behavioral patterns of variables, and correlating dependent and independent variables. The inclusion of system dynamics-based models in solid waste management has recently become more common. In this review, we used system dynamics to determine methods to disentangle solid waste management systems and analyzed different studies on solid waste management using system dynamics in different countries in detail. We also discussed the various software packages that are available for system dynamics and their usefulness for waste management. This review may help in understanding current solid waste management practices using system dynamics.

• 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.

• Korean System Dynamics Review
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• v.8 no.2
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• pp.51-82
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• 2007

The purpose of this paper is exploring changes in land use pattern when considering environmental carrying capacity. A sustainable development requires a society to define sustainability constraints, environmental carrying capacity. Environmental carrying capacity can be defined as a level of human activity a region can sustain at a desired level of quality of environment. This concept of environmental carrying capacity can be applied to land use to explore sustainable land use pattern. Since land use pattern can affect environment in an important way, exploring sustainable land use pattern within the limit of environmental carrying capacity can suggest useful implications for a sustainable regional management and planning. For this purpose, this paper built the environmental carrying capacity land use model and applied it to the Metropolitan Area, Korea. System dynamics modeling methods was used to build the model. The model developed in this paper consisted of 6sectors; population, housing, industry, land, environment, and traffic sector. The model limits its main focus on the NO2 level as an indicator of quality of environment in Metropolitan Area. Box model was translated into system dynamics model and combined to urban dynamics model to estimate NO2 level, the maximum number of population, industry structure, housing and maximum amount of land use for industrial, housing, and green space that can sustain desirable NO2 level. Metropolitan area was divided into 16 areas and the model was applied to each area. Since NO2 is flowing in and out from each area, model was built to allow this transboundering nature of air pollutants. Based on the model estimation, several policy implications for a sustainable land use pattern was discussed.

• Journal of Construction Engineering and Project Management
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• v.5 no.4
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• pp.1-6
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• 2015

Due to unique characteristics of small construction companies, safety management is comprised of complex problems. This paper aims to better understand the complexity and dynamics of safety management in small construction companies. A system dynamics (SD) model was built in order to capture the causal interdependencies between factors at different system levels (regulation, organization, technical and individual) and their effects on safety outcomes. Various tests were conducted to build confidence in the model's usefulness to understand safety problems facing small companies from a system dynamics view. A number of policies were analyzed by changing the value of parameters. The value of a system dynamics approach to safety management in small construction companies is its ability to address joint effects of multiple safety risk factors on safety performance with a systems thinking perspective. By taking into account feedback loops and non-linear relationships, such a system dynamics model provides insights into the complex causes of relatively poor safety performance of small construction companies and improvement strategies.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2002.05a
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• pp.70-70
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• 2002

• International conference on construction engineering and project management
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• 2015.10a
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• pp.92-96
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• 2015

Due to unique characteristics of small construction companies, safety management is comprised of complex problems (e.g., resources constraints, a lack of formalized management structures, low level of management safety commitment etc.). In order to understand causal interdependencies between safety factors at different system levels (regulation, organization, technical and individual), this paper aims to develop a system dynamics (SD) model of safety management in small construction companies. The purpose of the SD model is to better understand why small construction companies have low level of safety performance. A causal loop diagram (CLD) was developed based on literature, with an attempt to map causal relationships between variables. The CLD was then converted into stock and flow diagram for simulation. Various tests were conducted to build confidence in the model's ability to represent the reality. A number of policies were analyzed by changing the value of parameters. The value of a system dynamics approach to safety management in small construction companies is its ability to address joint effects of multiple safety risk factors on safety performance with a systems thinking perspective. By taking into account feedback loops and non-linear relationships, such a system dynamics model provides insights into the complex causes of relatively poor safety performance of small construction companies and improvement strategies.

• Environmental Engineering Research
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• v.19 no.2
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• pp.165-174
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• 2014

A model combining multi-dimensional discretized population balance equations with a computational fluid dynamics simulation (CFD-DPBE model) was developed and applied to simulate turbulent flocculation and sedimentation processes in sediment retention basins. Computation fluid dynamics and the discretized population balance equations were solved to generate steady state flow field data and simulate flocculation and sedimentation processes in a sequential manner. Up-to-date numerical algorithms, such as operator splitting and LeVeque flux-corrected upwind schemes, were applied to cope with the computational demands caused by complexity and nonlinearity of the population balance equations and the instability caused by advection-dominated transport. In a modeling and simulation study with a two-dimensional simplified pond system, applicability of the CFD-DPBE model was demonstrated by tracking mass balances and floc size evolutions and by examining particle/floc size and solid concentration distributions. Thus, the CFD-DPBE model may be used as a valuable simulation tool for natural and engineered flocculation and sedimentation systems as well as for flocculant-aided sediment retention ponds.

• Journal of Microbiology and Biotechnology
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• v.26 no.5
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• pp.900-908
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• 2016

The effects of algal inoculation on chemical oxygen demand (COD) and total nitrogen (TN) removal, and indigenous bacterial dynamics were investigated in municipal wastewater. Experiments were conducted with municipal wastewater inoculated with either Chlorella vulgaris AG10032, Selenastrum gracile UTEX 325, or Scenedesmus quadricauda AG 10308. C. vulgaris and S. gracile as fast growing algae in municipal wastewater, performed high COD and TN removal in contrast to Sc. quadricauda. The indigenous bacterial dynamics revealed by 16S rRNA gene amplification showed different bacterial shifts in response to different algal inoculations. The dominant bacterial genera of either algal case were characterized as heterotrophic nitrifying bacteria. Our results suggest that selection of indigenous bacteria that symbiotically interact with algal species is important for better performance of wastewater treatment.