• Journal of the Korean Geographical Society
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• v.42 no.6
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• pp.930-939
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• 2007

This study intends to demonstrate that the population decrease in the City of Busan has been resulted from the move of the city's population towards suburbs as well as the out-migration towards the Seoul metropolitan area. To grasp the pattern in the spatial shift of the Busan's population, I analyze the change of population and households within the city and the migration at the inter-regional and intra-metropolitan scales. The major findings of the study are as follows: First, Busan has experienced population decline since 1995, as other large cities, such as Seoul and Daegu have done. Second, despite the population decrease, the number of households has been increased in Busan. Third, the residents of Busan have mostly moved not only to the Seoul metropolitan area but also to the suburban region of Busan. This finding may well contradict the long-standing belief that the continued decrease in the Busan population could be the result of the out-migration toward the Seoul metropolitan area. Fourth, the residential suburbanization in Busan can be interpreted as the extensive intra-metropolitan dispersion, which means the growth of the Busan metropolitan area.

• Korean Journal of Remote Sensing
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• v.33 no.6_2
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• pp.1119-1137
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• 2017

This study assessed the water provisioning and climate mitigation ecosystem services of the urban forest in Seoul and Gyeonggi-do. The ecosystem service assessment is conducted based on natural function, natural function and population, and natural function and the beneficiary of the ecosystem service. Then, the impact of climate change on ecosystem services is analyzed to figure out the sensitivity of the impact on the beneficiary when the natural function of forest destroys under climate change. Gyeonggi-do has higher function-based water provisioning ecosystem service than Seoul. And population-based water provisioning ecosystem service appears to be higher in the densely populated area. On the other hand, beneficiary-based water provisioning ecosystem service by applying both natural water supply function and beneficiary distribution appears different with the result of population-based water provisioning service assessment. In other words, regions with high beneficiary population show higher ecosystem service than those with a low beneficiary population even though they have the same water storage function. In addition, climate change has a negative impact on the water provisioning ecosystem service. Under climate change, water provisioning service is expected to decrease by 26%. For climate mitigation service, regions close to the forest seem to have a low temperature, which indicates their high climate mitigation service. The center of the city with high beneficiary population shows high beneficiary-based ecosystem service. The climate change impacts the forest growth to decrease which affect the beneficiary-based climate mitigation ecosystem service to decrease by 33%. From this study, we conclude that beneficiary-based function and ecosystem service assessment is needed as well as the supply-based classification of forest function suggested by Korea Forest Service. In addition, we suggest that not only supply-based function classification and ecosystem service assessment but also beneficiary-based function classification and ecosystem service assessment is needed for managing the urban forest, which has been destroyed by climate change. This will contribute to revaluing cases where a forest with low natural function but high beneficiary-based ecosystem service, which is not considered under the current forest function-based assessment system. Moreover, this could assist in developing a suitable management plan for the urban forest.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.3
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• pp.1387-1390
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• 2014

Background: The aim of this study was to evaluate trends in incidence of breast cancer in women less than 40 years in Asia. Materials and Methods: Registered cases of female breast cancer age less than 40 years and corresponding person years were ascertained from the CI5plus for 10 registries in Asia for the duration of 1970- 2002. Cases were categorized into three age groups: 16-40, 16-29, and 30-40. The 16-40 age group was adjusted to world age population structure. Joinpoint regression analysis was conducted to determine the annual percent of change (APC) and the average annual percent of change (AAPC) for each age group. Results: A total of 23,661 cases of breast cancer occurred in the 10 registries during the 32 years (1970-2002) of follow-up. The overall age adjusted (16-40 group) breast cancer incidence rate increased from 2.28-4.26 cases per 100,000 population corresponding to an AAPC of 2.6% (95%CI 2.1, 3.0). The trend in incidence for the age group 16-29 increased from 0.45-1.07 corresponding to an AAPC of 2.8% (95%CI 1.9, 3.7). In age group 30 to 40, the incidence ranged from 13.3 in year 1970 to 24.8 in year 2002 corresponding to an AAPC of 2.7% (95% CI 2.3, 3.1). There were two statistically significant changing points in the regression line for the age groups 30-40 and 16-40: one point in the year 1975 with an APC of 6.1 (5.1, 7.1), and the other in 1985 with an APC of 0.4% (0.01, 0.8). Conclusions: Our study proved that: 1) the incidence of breast cancer in young women has increased in Asian population during the study period; 2) the rate of increase was very high during the period of 1980-1990.

• Animal Bioscience
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• v.36 no.3
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• pp.417-428
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• 2023

Objective: Few studies have genetically monitored chickens over time, and no research has been conducted on ducks. To ensure the sustainable management of key duck breeds, we used microsatellite markers to monitor Brown Tsaiya ducks over time genetically. Methods: The second, fourth, sixth to eighth generations of the Brown Tsaiya duck selected for feeding efficiency and control lines were included in this study to investigate the genetic variations, effective population size, population structure and the differentiation between populations over time with 11 microsatellite markers derived from Brown Tsaiya duck. Results: The results showed there were a slight decrease in the genetic variations and an increase in within-population inbreeding coefficient (F_IS) in both lines, but no consistent increase in F_IS was observed in each line. The effective population size in the second and eighth generations was 27.2 for the selected line and 23.9 for the control line. The change in allele richness showed a downward trend over time, and the selected line was slightly lower than the control line in each generation. The number of private alleles (N_p) in the selected line were higher than in the control line. Moderate differentiation was observed between the second and eighth generations in the selected line (F_ST = 0.0510) and the control line (F_ST = 0.0606). Overall, differentiation tended to increase with each generation, but genetic variation and structure did not change considerably after six generations in the two lines. Conclusion: This study provides a reference for poultry conservation and helps to implement cross-generation genetic monitoring and breeding plans in other duck breeds or lines to promote sustainable management.

• Proceedings of the Korea Water Resources Association Conference
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• 2019.05a
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• pp.397-397
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• 2019

With the consequences of climate change becoming more evident, research on climate-associated risks has become a basis for climate adaptation and mitigation. Amongst the different sectors and natural resources considered in assessing such risks, drought is one impact to our environment that experiences stress from climate change but is often overlooked and has the potential to bring severe consequences when drought occurs. For example, when temperatures are higher, water demand increases and water supply decreases; when precipitation patterns fluctuate immensely, floods and droughts occur more frequently at greater magnitudes, putting stress on ecosystems. Hence, it is important for us to evaluate drought risk to observe how different climate change and socioeconomic scenarios can affect this vital life resource. In this study, we review the context of drought risk on the basis of climate change impacts and socioeconomic indicators. As underlined in the IPCC AR5 report, the risks are identified by understanding the vulnerability, exposure, and hazards of drought. This study analyzed drought risk on a global scale with different RCP scenarios projected until the year 2099 with a focus on the variables population, precipitation, water resources, and temperature.

• Journal of the Korean Geographical Society
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• v.51 no.6
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• pp.837-851
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• 2016

The growth and development of Gwangyang city was a result of the POSCO Gwangyang Works, and Gwangyang city is one of typical firm citys in Korea. The objective of this study is to identify and examine the change of migration and population structure in Gwangyang city from 2001 to 2010. Since 1981, total number of population of Gwangyang city increased from 78,478 in 1981 to 145,512 in 2010. The population structure by age was changed with population increase since 2001, and 30-40 aging group was 35% of total in 2010. During 2001-2010, the netmigraion showed -2,925 people, however, the number of inmigrants were overtaking the number of out-migrants since 2008. The most common reason of in-migrants was occupation(49.5%). Factors influencing Gwangyang City's population growth and oversupply are the location of POSCO Gwangyang Works and steel-related enterprises, opening and construction of Gwangyang container berth, the related development projects and establishment of Gwangyang Bay Area Free Economic Zone, and the local policies of Gwangyang City connected with these large-scale national projects. As a result, the number of manufacturing-related businesses increased due to various regional development projects conducted in Gwangyang City, and the growth of the business continued to increase due to the increase of younger people and births.

• Health Policy and Management
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• v.2 no.1
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• pp.147-166
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• 1992

The purpose of this study is to analyze the effects of the health center hospital on the health service utilization pattern of the rural population in a county. Two field studies had been conducted in Yonchon County, Kyunggi Province, on February 1989 and on August 1991 before and after the establishment of the Yonchon health center hospital. This study revealed that Yonchon health center hospital occupied 7.3% of total outpatient visits and 16.8% of hospitalization of the county population and the self-sufficient rate of the outpatient visit and hospitalization of Yonchon County between two field studies increased by 1.7% and 20.9% each. Yonchon health center hospital contributed to the growth of the public health sector but it weakened the role of health sub-centers. For the efficient health service utilization of the population in that County, more investment to health center hospital would be needed and the primary health activities of the health subcenter should be enforced.

• 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.

• KDI Journal of Economic Policy
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• v.42 no.3
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• pp.1-32
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• 2020

This paper studies urban growth in Korean cities. First, I document that population growth patterns change over time and that the current population distribution supports random urban growth. I confirm two empirical laws-Zipf's law and Gibrat's law-both of which hold in the period of 1995-2015, but do not hold in the earlier period of 1975-1995. Second, I find a systematic employment growth pattern of Korean cities in spite of the random population growth. I examine market access effects on employment growth. Market access, a geographical advantage, has a significant influence on urban employment growth. The market access effect is higher in the Seoul metropolitan area than in the rest of the country. This effect is stronger on employment growth in the manufacturing industry compared to employment growth in the service industry. These results are robust with various checks (e.g., different definitions of urban areas). The results here suggest that policymakers should consider geographical characteristics when they make policy decisions with respect to regional development.

• Korean Journal of Environmental Agriculture
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• v.16 no.4
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• pp.291-294
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• 1997

The purpose of this study was to investigate the change of microbial flora of using coal fly ash as humidity conditioner during the household garbage composting.The summarized results of microbial flora were as follows:There was no difference of t he seasonal fluctuation of mesophilic and themophilic microorganisms.The population of thermophilic actinomycetes was rapidly increased in winter,but not much changed in spring and summer.Thermophilic and mesophilic fungal flora were increased at the same time,but the population of thermophilic fungal flora was smaller than that of mesophilic. The population of bacteria, actinomycestes and fungi showed not much difference.