• The Transactions of the Korean Institute of Electrical Engineers D
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• 제50권12호
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• pp.597-603
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• 2001

In the mathematical model for the transmission dynamics of HIV infection described in previous papers, the population under consideration is assumed to be homogeneous community of homosexual males for which the parameter x represents the constant rate at which individual members of the population acquire new sexual partners. This is a gross oversimplification since it is well known that individuals vary widely in their levels of sexual activity and in this papers the heterogeneous model is modified to allow for this variation. The pattern on the epidemic character of HIV, the causative agent of AIDS, was analysed by heterogeneous-mixing model. The computer simulation was performed using real date.

• Journal of the Korean Society for Industrial and Applied Mathematics
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• 제14권3호
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• pp.189-200
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• 2010

A numerical method is proposed and analyzed to approximate a mathematical model of age-dependent population dynamics with spatial diffusion. The model takes a form of nonlinear and nonlocal system of integro-differential equations. A finite difference method along the characteristic age-time direction is considered and primal mixed finite elements are used in the spatial variable. A priori error estimates are derived for the relevant variables.

• Journal of the Korean Statistical Society
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• 제10권
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• pp.145-157
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• 1981

Regional relocation of population in Korea is required strongly from natural and environmental sides for substantial growth of economy and the rigorous revival national economy against especially internationalization. This paper aimed for analysed the population distribution by regional and special characteristics of the inter-migration and showed the direction of population policy through the model building. Relocation methods of population by region has been examined through the process from the approach method by Haurin's production function to the approach by the utility function. The examination of the development model is done efficiently, how utility these approach models are depends on that scientific and composite plan for population problems against forced policy should be taken precedence.

• Korean System Dynamics Review
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• 제12권1호
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• pp.59-74
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• 2011

This article deals with an economic evalutation of the 'Pasture Project of Kum River', which is the farming plan of mitten crabs in a stream of it. An augmented model of social capital is based on the past ecological-economic system dynamics model and elaborated further with suggestions of social capital literature. During the modeling process a chain diagram of causal relations and its relevant mathematical equations are presented for simulating the project performance, and the simulation results are provided to contrast the dynamic behaviors of the former ecological-economic model with ones of the new model incorporating social capital. The results indicate that an increase in the economic benefit of the project could happen in case of considering the process of social capital accumulation around the case area, which can be regarded as a remarkable trial to approve the common confidence in the role of social capital to enhance an economic achievement.

• Proceedings of the Korea Society for Simulation Conference
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• 한국시뮬레이션학회 2001년도 The Seoul International Simulation Conference
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• pp.20-36
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• 2001

The purpose of this paper is estimating environmental carving capacity of Seoul Metropolitan Area for a sustainable city management using system dynamics model. A sustainable development requires a society to define sustainability constraints or environmental limits, environmental carving capacity. Environmental carving capacity can be defined as the level of human activity which a region can sustain at an acceptable quality of life level. This concept of environmental carving capacity has several important application to sustainable city planning and management. If the limitation of a human activity can be supported by a scientific data on carving capacity, the resulting decision and actions could more easily win public support for a sustainable development. However, one of the key issues is how to operationalize the carving capacity. In this paper, the environmental carving capacity was operationalized as a maximum number of industry structure, population, and housing that can sustain certain level of environmental quality of Seoul Metropolitan Area. The model developed in this paper consisted off sectors: population, housing, industry, land, and environmental sector. The model limits its main focus on the NO$_2$level of ambient air of Seoul. Carving capacity Seoul Metropolitan Area was estimated by figuring out the maximum number of population, industry structure, housing at an equilibrium point that sustain a desirable NO$_2$level. Based on the model estimation, several policy implications for a sustainable city management was discussed.

• Proceedings of the KSRS Conference
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• 대한원격탐사학회 1998년도 Proceedings of International Symposium on Remote Sensing
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• pp.3-8
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• 1998

Using GIS and socio-economical data the relationship between human activities and global environmental change Is Analysed from the view point of food productivity and CO2 emission. Under the assumption that the population problem, the food problem and global warming due to energy consumption can be stabilized through managing land use, impacts of human activities such as consumption of food, energy and timber on global environment changes, and global population capacity are Analysed using developed system dynamics model in the research. In the model the world is divided into two groups: OECD countries and the others. Used global land use data set Is land cover map derived from satellite data, and potential distribution of arable land is estimated by the method of Clamor and Solomon which takes into consideration spatial distribution of climate data such as precipitation and evapotranspiration. In addition, impacts of CO2 emission from human activities on food production through global warming are included in the model as a feedback. The results of the analysis for BaU scenario and Toronto Conference scenario are similar to the results of existing models. From the result of this study, the human habitability in 2020 is 8 billion people, and CO2 emission in 2020 based on BaU Scenario and on Toronto Scenario is 1.7 and 1.2 times more than the 1986's respectively. Improving spatial resolution of the model by using global data to distribute the environmental variables and sauce-economical indices is left for further studies.

• Communications of the Korean Mathematical Society
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• 제22권4호
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• pp.623-640
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• 2007

The Lotka-McKendrick model which describes the evolution of a single population is developed from the well known Malthus model. In this paper, we introduce the Lotka-McKendrick model. We approximate the solution to the model using hp-discontinuous Galerkin finite element method. The numerical results show that the presented hp-discontinuous Galerkin method is very efficient in case that the solution has a sharp decay.

• Proceedings of the Korean System Dynamics Society
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• 한국시스템다이내믹스학회 2006년도 추계학술대회 발표논문집
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• pp.49-69
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• 2006

본 논문은 선행연구인 정회성${\cdot}$전대욱 (2005)의 모형을 중심으로 선행연구에서 미처 다루지 못한 체계 변화 및 모형 확장 등에 대해 다루고 있다. 선행연구에서는 우리나라의 참게 복원사업에 대한 개체수 동태모형(population dynamics)과 자원 경제학적 이론모형을 근거로 생태${\cdot}$경제 통합시스템에 대한 동태모형을 도출하고 이를 통해 실증분석을 수행하였는데, 본 논문에서는 이 통합 모형에 있어서 밀도 제약(density restriction)과 공식 행위(cannibalistic behavior), 주민참여에 의한 환경개선 등 일련의 가정들에 대한 확장을 통해 보다 일반화된 통합체계 및 시스템 다이내믹스 분석을 제시한다. 이와 같은 모형 확장 및 파라메터의 내생화 등은 관련 피드백 루프들의 변형과 추가 등을 의미하며, 이와 같은 변화를 포함한 확장 모델을 제시하고 분석함으로써 참게 복원사업에 대한 보다 폭넓은 논의를 제시하고자 한다.

• Korean System Dynamics Review
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• 제11권1호
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• pp.27-57
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• 2010

This article deals with an ecological-economic analysis of the 'Pasture Project of Kum River', which is the farming plan of mitten crabs using Jichun, a stream of the River Kum where the natural propagation of mitten crabs are blocked because of the estuary dam constructed in 1990. Toward analyzing the ecological and economic effects of the crab releasing and harvesting activities in Jichun, a two-stage cohort model of population dynamics with cannibalistic behaviors and density restrictions in biomathematics is adopted, despite of the current infertility in Kum, considering the opportunity of establishing dam fishways in the near future. This study moreover presents a method of parameter estimation especially with assuming a steady state of the ecosystem, and performs various analyses such as the risk measurement of climate change and the economic value of such fishways.

• Proceedings of the Zoological Society Korea Conference
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• 한국동물학회 2003년도 한국생물과학협회 학술발표대회
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• pp.36-36
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• 2003

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