• Korean Journal of Environment and Ecology
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• v.32 no.6
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• pp.582-590
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• 2018

Although there are many studies of the effect of climate change on the breeding phenology and community diversity of amphibians, the studies of variations in reproductive population size of individual species according to climate change are still lacking. We examined the effect of climate change on the reproductive population size of Rana huanrenensis and Hynobius leechii, which bred in mountain valleys, by surveying the reproductive population of the two species between 2005 and 2012 and analyzing the correlation between the variation of the outdoor population and the surrounding climate change factors, obtained from a meteorological observatory located at 5.6 km from the study site. The size of the reproductive population of the two species commonly fluctuated with aan pproximately 3.5-year cycle. That of H. leechii, in particular, decreased significantly over eight years. The air temperature tended to more closely relate with the reproductive population size of R. huanrenensis as was the case of the precipitation with that of H. leechii. The yearly mean highest temperature and spring mean temperature variation consistently decreased over the eight years, and the latter was related with the significantly decreased size of H. leechii reproductive population. These results showed that recent climate change directly could affect the reproductive population size of amphibians, particularly H. leechii, which breeds in mountain valleys.

• Journal for History of Mathematics
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• v.29 no.6
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• pp.353-363
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• 2016

In mathematical population ecology which is an academic field that studies how populations of biological species change as times flows at specific locations in their habitats, PDE models have been studied in many aspects and found to have different properties from the classical ODE models. And different approaches to PDE type models in mathematical biology are still being tried currently. This article investigate various forms to express diffusion effects and review the history of PDE models involving diffusion terms in mathematical ecology. Semi-linear systems representing the spatial movements of each individual as random simple diffusion and quasi-linear systems describing more complex diffusions reflecting interspecific interactions are studied. Also it introduce a few of important problems to be solved in this field.

• Journal for History of Mathematics
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• v.33 no.3
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• pp.167-177
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• 2020

Cooperative behavior may seem contrary to the notion of natural selection and adaptation, but is widely observed in nature, from the genetic level to the organism. The origin and persistence of cooperative behavior has long been a mystery to scientists studying evolution and ecology. One of the important research topics in the field of evolutionary ecology and behavioral ecology is to find out why cooperation is maintained over time. In this paper we take a historical overview of mathematical models representing cooperative relationships from the perspective of mathematical biology, which studies population dynamics between interacting biological groups, and analyze the mathematical characteristics and meanings of these cooperative models.

• Proceedings of the National Institute of Ecology of the Republic of Korea
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• v.4 no.3
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• pp.115-126
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• 2023

Understanding the carrying capacity of a habitat is crucial for effectively managing populations of wild boars (Sus scrofa), which are designated as harmful wild animal species in national parks. Carrying capacity refers to the maximum population size supported by a park's environmental conditions. This study aimed to estimate the appropriate wild boar population size by integrating population characteristics and habitat suitability for wild boars in the Bukhansan National Park using the HexSim program. Population characteristics included age, survival, reproduction, and movement. Habitat suitability, which reflects prospecting and resource acquisition, was determined using the Maximum Entropy model. This study found that the optimal population size for wild boar ranged from 217 to 254 individuals. The population size varied depending on the amount of resources available within the home range, indicating fewer individuals in a larger home range. The estimated wild boar population size was 217 individuals for the minimum amount of resources (50% minimum convex polygon [MCP] home range), 225 individuals for the average amount of resources (95% MCP home range), and 254 individuals for the maximum amount of resources (100% MCP home range). The results of one-way analysis of variance revealed a significant difference in wild boar population size based on the amount of resources within the home range. These findings provide a basis for the development and implementation of effective management strategies for wild boar populations.

• Korean Journal of Human Ecology
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• v.20 no.1
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• pp.71-90
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• 2011

The aim of this study was to investigate on characteristics of sociological and demographic population, marital conflicts and expectations to family counselors' cultural competence surrounding factors of cultural adaptation among immigrated women. This study conducted a survey of 236 immigrated women in Kyonggi province, Seoul metropolitan cities, Cholla and Chunchung provinces and Incheon. The results of this study are as follows: First, a relatively few marital conflicts were found, as a whole, while they had the high levels of expectation to family counselors' cultural competence. Second, immigrated women can be clustered as three different types: 'multiplicity type', 'undifferentiated type' and 'adaptation type'. Third, sociological and demographic population characteristics which were subdivided and clustered according to cultural adaptation made the significant difference between each population. Population with multiplicity type out of the above-stated three types accounted for the highest conflict rates, while population with 'adaptation' type accounted for the lowest conflict rates. Lastly, expectations to family counselors' cultural competence made the significant difference among each population. Population with multiplicity type showed the highest expectation levels on expectations to family counselors' cultural competence, while population with undifferentiated type showed the lowest levels.

• Proceedings of the Korea Society of Environmental Biology Conference
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• 2000.11a
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• pp.8-8
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• 2000

• Journal for History of Mathematics
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• v.24 no.2
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• pp.47-59
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• 2011

Various mathematical models have been widely studied recently in both fields of mathematics and ecology since they help us understand the dynamical process of population changes in biological species living in a certain habitat and give useful predictions. The world population model proposed by Malthus, a British economist, in his work 'An Essay on the Principle of Population' published in the period of 1789~1826 is one of the early mathematical models on population changes. Malthus' models and the carrying capacity models of Verhulst in 1845 were based on exponential type functions. The independent research field of mathematical ecology has been started from Lotka's works in 1920's. Since then various different mathematical models has been proposed and examined. This article mainly deals with single species population change models expressed in terms of ordinary differential equations.

• Human Ecology Research
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• v.62 no.2
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• pp.261-278
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• 2024

This study aims to enhance the life satisfaction of the elderly population in South Korea by exploring their satisfaction levels and identifying influencing factors. Utilizing data from the 17th Korean Welfare Panel, which includes 6,260 individuals aged 65 and older, this study employs independent sample t-tests, one-way ANOVA, and hierarchical regression analysis. The results showed that, in general, the life satisfaction of the elderly population was somewhat lower than that of the general adult population in all areas, except for job satisfaction and satisfaction with housing. Key factors influencing life satisfaction among the elderly population include demographic characteristics (gender, age, economic activity, residence, education level), subjective health status factors, financial factors (disposable income, monthly living expenses), and psychological factors (depression, self-esteem). Notably, psychological factors, particularly self-esteem and depression, profoundly affect all life satisfaction domains. Enhancing life satisfaction necessitates fostering positive self-perception and capabilities in the elderly population, suggesting the need for programs focused on positive emotional experiences. Moreover, depression significantly reduces life satisfaction, underscoring the importance of policy interventions to address negative emotions in this demographic. This study is expected to provide basic data for establishing concrete and effective policies for improving the quality of life for the elderly population. Additionally, by highlighting the importance of positive psychological factors, it is anticipated that the study will offer a new direction for improving the life satisfaction of the elderly population.

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 2000.04a
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• pp.139-141
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• 2000

• Proceedings of the Korean Society of Environment and Ecology Conference
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• 1999.04a
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• pp.43-46
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• 1999