• Journal of the Korean association of regional geographers
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• v.11 no.6
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• pp.559-570
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• 2005

The purpose of this paper is to estimate the effect of population change on waste emission in the case of Busan City. The results are as follows : First, population and waste emission in Busan City Show decreasing pattern since 1995. According to increase or decrease of population and waste emission, The 16 Gus in Busan City are categorited into 5 types. Comparing the difference of population and waste emission between 1995 and 2003, we find out a similar trend by 16 Gus in Busan City. Second, the waste emission shows the positive relation with the number of population and the land by use. But there exists multicollinearity between population and the land by use, and the population is considered the main factor of waste emission. Third, the population causes 92% or more of the waste emission in Busan City, and future researches are required for the additional causes of waste generation.

• Korean Journal of Environment and Ecology
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• v.30 no.6
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• pp.970-976
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• 2016

Determining age structure of the population of an endangered species is critical because it could provide basic information about population dynamics. In this study, we assessed the possibility if the growth lines on dorsal scutes of the national monument as well as endangered Reeves' turtle (Mauremys reevesii) can reliably estimate actual ages of the 100 turtles of which actual ages were known and have been housed in Seoul Zoo. We counted the number of growth lines on the first four dorsal scutes and the first left and right lateral scutes of each turtle and compared those with their known actual ages. Ages estimated by the growth lines were overestimated at between 1 and 5 actual ages, but underestimated at between 6 and 9 actual ages, indicating that age estimation using growth lines is only partially applicable at actual ages of less than 6 years old. In addition, using length and width of turtle's dorsal plates, we produced growth curves with equations to estimate actual ages of females combined with juveniles, but its application to estimate actual ages was not reliably possible because all subject turtles which used were at relatively young ages. In conclusion, when estimating actual ages of Reeves' turtles using the number of growth lines on the dorsal scutes, it is recommend to use minimum values at less than 6 lines, but use maximum values at more than 7 lines. As the first study which estimated actual ages of a turtle species using growth lines on the dorsal scutes in Korea, our results could be useful to estimate ages of the endangered Reeve's turtles in the field although its application might be limited.

• Journal of Life Science
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• v.18 no.2
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• pp.175-179
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• 2008

Cornus controversa is a long-lived woody species mostly distributed in East Asia. Random amplified polymorphic DNA (RAPD) markers were used to investigate the genetic diversity and population structure of Korean populations of this species. A high level of genetic variation was found in seven populations of C. controversa. The mean genetic diversity (H) was 0.222 across populations, varying from 0.200 to 0.238. Eighty of the 93 loci (86.0%) showed detectable polymorphism in at least one population. Total genetic diversity values ($H_T$) varied between 0.192 and 0.231, giving an average overall polymorphic loci of 0.212. The interlocus variation of genetic diversity within populations ($H_S$) was high (0.167). Mean of genetic diversity in C. controversa was higher than average values for species with similar life history traits. The sexual reproduction, perennial habitat, and longevity are proposed as possible factors contributing to high genetic diversity. On a per locus basis, the proportion of total genetic variation due to differences among populations ($G_{ST}$) ranged from 0.169 to 0.278 with a mean of 0.216, indicating that about 21.6% of the total genetic variation was among populations. An indirect estimate of the number of migrants per generation (Nm=1.893) indicated that gene flow was extensive among Korean populations of C. controversa.

• Journal of Environmental Health Sciences
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• v.45 no.3
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• pp.273-284
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• 2019

Objective: This study was performed to estimate the number of those who used humidifier disinfectants (HDs) and experienced health effects from exposure to HDs in Korea between 1994 and 2011. Methods: A nationwide interview survey was conducted for the representative sample to identify the proportion of those who used HDs among the general population (n=3,001). Another online survey was conducted for those exposed to HDs to find the proportion of those who experienced health effects among those who were exposed to HDs (n=3,993). Statistics for population size by region and year (1994-2011) were used to estimate the cumulative number of those exposed to HDs and those who experienced health effects. In terms of the proportion of those exposed to HDs, those less than 30 years of age were excluded due to an issue related to information bias. Various approaches for estimation included the capture-recapture method for estimation of those who experienced health effects. Results: The cumulative proportion of those exposed to HDs was 6.7% among the general population, and the proportion of those who experienced health effects among those who were exposed to HDs was 13.9%. Based on these factors, it was estimated that 3.5 to 4.0 million people were exposed to HDs and 350 to 400 thousand experienced health effects at least requiring visiting a hospital. Conclusion: It is suggested that a nationwide representative sample may be essential for population size estimation of those exposed to environmental risk factors and of those who experienced health effects.

• The Journal of Fisheries Business Administration
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• v.41 no.2
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• pp.45-60
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• 2010

The objective of this article was to estimate the market size of recreational fishing in Korea. Data were collected through sample surveys of 3,081 households nationwide in 2008. The number of anglers was directly estimated by applying weights expressed as the ratio of population to the sample. Yields and expenditures were estimated based on modules developed. On the basis of the results, a total of 6,524 thousand anglers caught an estimated 643,343 thousand fish, divided 65.2% on inland lake and 34.8% on saltwater. An angler caught about 98 fish on average in 2008. A typical angler went fishing 9.6 times, divided 8.4 times on inland lake and 5.5 times on sea. An annual expenditure of 5,233.6 billion won was estimated. The total was divided 2,851.4 billion won on inland lake(54.5%) and 2,382.2billion won on saltwater(45.5%). An average angler spent 802 thousand won a year. This study also estimated volumes by various types of fish.

• Journal of Korean Society of Transportation
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• v.12 no.1
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• pp.85-95
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• 1994

While bicycles are an exhaust-free and low energy consuming mode of transport, the use of them is getting decreased. The aim of this research is to find out current levels of bicycle ownership and to estimate the ownerships of the bicycles by spatial structure and social factors in the metropolitan area. The parameters which affect on the characteristics of the bicycle ownership are classified into aggregate and disaggregate categories. The ownerships of the bicycles are estimated by the multiple regression analysis using urban characteristics data and the binary logit analysis using household characteristics data. The results of this study to population, car ownership, and number of male in the household, and negatively by the population density.

• Korea journal of population studies
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• v.27 no.1
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• pp.81-90
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• 2004

The aim of this study is to estimate the own price elasticities for tobacco demand among Korean urban households. Using the expenditure data of smoking urban households, the quadratic almost ideal demand system is estimated. The estimated price elasticity of tobacco demand is -0.52 on the average value. The higher households income, the higher education level of households head, and the higher number of children, the tobacco demand gets more inelastic.

• Health Policy and Management
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• v.29 no.3
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• pp.312-322
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• 2019

Background: Since 2003, Korea has consistently shown the highest suicide rate among the Organization for Economic Cooperation and Development countries, and suicide remains the major cause of death. In particular, men are 2-3 times more likely to commit suicide than women, which called the 'gender paradox of suicide.' The areas with frequent suicide have spatially clustered patterns because suicide with a social contagion spreads around the neighborhood. The purpose of this study was twofold. The first was to estimate the hotspot areas of age-standardized male suicide mortality from 2008 to 2015. The second was to analyze the relationship between the hotspot areas and the regional characteristics for study years. Methods: The data was collected through the Korean Statistical Information Service. The study areas were 227 si gun gu administrative districts in Korea. The hotspot area was used as a dependent variable. Socio-demographic variables (number of marriages per 1,000 population, number of divorces per 1,000 population, and urbanization rate), financial variables (financial independence and social security budget), and health behaviors (EuroQol-5 dimension [EQ-5D], and depression experience rate) were used as independents variables. Results: The hotspot areas were commonly located in Gangwon-do, Chungcheongnam-do, Gyeongsangbuk-do, and Chungceongbuk-do. According to the results of panel logit regression, the number of divorces per 1,000 population, social security budget, and EQ-5D were statistically significant variables. Conclusion: The results of hotspot analysis showed the need for establishing a prevention zone of suicide using hotspot areas. Also, medical resources could be considered to be preferentially placed in the prevention zone of suicide. This study could be used as basic data for health policymakers to establish a suicide-related policy.

• Journal of the Korean Operations Research and Management Science Society
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• v.42 no.1
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• pp.29-41
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• 2017

Korea is expected to become a super-aged society by 2050. Given an aging population and the increasing pressure for the early retirement, a sufficient social safety net for elderly population becomes important. The Korean government introduced public reverse mortgage program in 2007, which is a product for aging seniors and the elderly, The number of reverse mortgage subscribers has also steadily grown. The demand continues to grow, but the reverse mortgage over a long period of time is a highly uncertain and risky product in the position of guarantee or lending institution. Thus, suitable demand prediction of the reverse mortgage subscribers is necessary for stable and sustainable operation. This study uses a Bass diffusion model to forecast the long-term demand for reverse mortgage and provides insight into reverse mortgage by forecasting demand for stability and substantiality of the loan product. We represent the projections of new subscribers on the basis of the data obtained from Korea Housing Finance Corporation. Results show that potential market size of Korean reverse mortgage reaches approximately 760,000-1,160,000 households by 2020. We validate the results by comparing the estimate of the cumulative number of subscribers with that found in literature.

• Journal of the Korean housing association
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• v.21 no.3
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• pp.125-134
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• 2010

The purpose of this study is to estimate the housing demands in order to address a suitable housing policy for a metropolitan city of Daegu in South Korea. Although the population of Daegu declines, a number of households increase since a number of people per households decrease. Currently a household with four people is a main housing type, however it is expected that a household with one or two increase. In 2017, a household with one will be dominant. Estimating housing sizes and their demand, the households below $60\;m^2$ gradually decline while those over $85\;m^2$ is expected to rise. Nevertheless, the demands for the house below $60\;m^2$ in its size increase at 39.2 per cent. Currently a house with $60\;m^2$ is being constructed. In particular, that of $85\;m^2$ gradually increases. The current trends may result in the widening gaps between the household demand and supply of Daegu. Therefore, it is recommended that relevant local authorities and developers should consider providing various house sizes by taking the current housing demand of Daegu into account.