• Korea journal of population studies
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• v.33 no.2
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• pp.85-111
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• 2010

South Korea has experienced a rapid fertility decline and notable mortality improvement. As the drop in TFR was quicker and greater in terms of tempo and magnitude, it cast a new challenge of population projection - how to improve the forecasting accuracy in the country with a super-low fertility pattern. This study begin with the current status of the national population projection as implemented by Statistics Korea by comparing the 2009 interim projection with the 2006 official national population projection. Secondly, this study compare the population projection system including projection agencies, projection horizons, projection intervals, the number of projection scenarios, and the number of assumptions on fertility, mortality and international migration among super-low fertility countries. Thirdly we illustrate a stochastic population projection for Korea by transforming the population rates into one parameter series. Finally we describe the future challenges of the national population projection, and propose the projection scenarios for the 2011 official population projection. To enhance the accuracy, we suggest that Statistics Korea should update population projections more frequently or distinguish them into short-term and long-term projections. Adding more than four projection scenarios including additional types of "low-variant"fertility could show a variety of future changes. We also expect Statistics Korea topay more attention to the determination of a base population that should include both national and non-national populations. Finally we hope that Statistics Korea will find a wise way to incorporate the ideas underlying the system of stochastic population projection as part of the official national population projection.

• Korea journal of population studies
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• v.33 no.1
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• pp.161-189
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• 2010

Dealing with uncertainty has been a critical issue in demographic and population forecasting since 1980. This study reviews methodological developments in demographic and population forecasting over the last several decades. First, this study reviews the important issue of the uncertainty surrounding demographic forecasts. Several limitations of the traditional scenario approach to dealing with uncertainty are also discussed. Second, in forecasting demographic processes such as mortality, fertility, and migration, three approaches of stochastic forecasting are identified and discussed: expert judgment, statistical modeling, and analysis of historical forecast errors. Finally, this study discusses the current issues and directions for future research in stochastic demographic forecasting.

• Journal of Korean Society of Rural Planning
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• v.28 no.2
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• pp.61-69
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• 2022

This study categorizes and identifies the characteristics of the living areas of rural dwellers through cluster analysis using mobile floating population data. As a result, rural areas in Korea were classified into 34 rural living areas, and 5 types of rural living areas were derived. Although the 'Suburban in Mega City Areas' and 'Suburban in Regional City Areas' derived through this study have advantages in terms of accessibility to large cities, they are important for rural space management as they can undermine the unique values of rural areas due to urban expansion. In addition, 'Unclassified areas' have low accessibility in the national space, and there is a need to provide their own settlement environment. The population of rural areas in Korea exhibited a phenomenon of widespread migration. This means that rural residents who depend on metropolitan areas are provided with SOC beyond administrative boundaries. Therefore, there is a need to move away from establishing a homogeneous regional plan that does not consider population movement. Through this study, it was possible to understand the rural living area formed by the population movement occurring in the rural area. This is different in that the existing studies classified the national space based on the interconnectedness between regions, beyond the limitations of categorizing regions with homogeneous characteristics based on endogenous indicators. At this point in time when the need for a rural space plan is emphasized, it is important to understand the living area of rural dwellers and to design an appropriate rural plan. Therefore, the establishment of a rural plan suitable for the region using the results of this study can increase the efficiency of the project for revitalization of the rural area and contribute to the creation of an attractive national space.

• Ocean and Polar Research
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• v.34 no.3
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• pp.275-286
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• 2012

Over the last 20 years there have been more than 3000 peer-reviewed papers relating to climate change and biodiversity published, and still the numbers are increasing. However, most studies focused on the impacts of climate change at population or community levels, and the results invariably reveal that there has been, or will be, a negative effect on the structure and pattern of biodiversity. Moreover, the climate change models and statistical analyses used to test the impacts are only newly developed, and the analyses or predictions can often be misled. In this review, I ask why an individual's life history is considered in the study how climate change affects biodiversity, and what ecological factors are impacted by climate change. Using evidence from a range of species, I demonstrate that diverse life history traits, such as early growth rate, migration/foraging behaviour and lifespan, can be shifted by climate change at individual level. Particularly I discuss that the optimal decision under unknown circumstance (climate change) would be the reduction of the ecological fitness at individual level, and hence, a shift in the balance of the ecosystem could be affected without having a critical impact on any one species. To conclude, I summarize the links between climate changes, ecological decision in life history, the revised consequence at individual level, and discuss how the finely-balanced relationship affects biodiversity and population structure.

• Korea journal of population studies
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• v.11 no.1
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• pp.185-196
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• 1988

This study considers inter-jurisdictional fiscal externalities between a central city and suburbs, rigorously examines. and empirically tests the suburban-exploitation-of-central-cities hypothesis. Using micro-migra4ion data, house-holds 'intra-metropolitan migration between 1985 and 1990 Is examined based on a random utility model. It is found that efficient population distribution between a central city and suburbs can be achieved when local government stake into account inter-jurisdictional externalities. External aids from the federal and state governments should be given to public services such as education, welfare, health, and employee retirement services, if they intend to arrest central city decline. Regional tax sharifs can be another way of dealing with these externalities.

• Journal of Environmental Science International
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• v.30 no.10
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• pp.811-820
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• 2021

The population variation of Spanish mackerel (Scomberomorus niphonius) according to its major prey abundance was analyzed using monthly catches of coastal set net fisheries in the southern waters off Gyeongsangnam-do and eastern waters off Gyeongsangbuk-do of Korea from 2006 to 2019. The abundance of Spanish mackerel and its prey species fluctuated almost simultaneously with time lags of +2 to -2 months between the set net fisheries in the southern and eastern waters. The generalized additive model revealed that the abundance of Spanish mackerel was influenced by its prey species such as hairtail and anchovy in southern waters, and common mackerel and horse mackerel in eastern waters. The model deviance explained 49% and 42% of Spanish mackerel abundance in southern and eastern waters respectively. These results suggest that the abundance of Spanish mackerel is affected by seasonal migratory prey fish species in the coastal areas and can be linked to their northerly migration.

• Journal of Ecology and Environment
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• v.31 no.3
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• pp.183-191
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• 2008

To determine the age structure of a Hynobius leechii breeding population and analyze relationships between the order of entrance to breeding ponds and physical parameters and age, we studied a wild population of the species in the Research Forests of Kangwon National University in Chuncheon, Kangwon, South Korea from March 16 to April 13, 2005. The age of breeding males ranged one to nine years old and that of females ranged from three to nine years old. The asymptotic sizes of males and females were 6.36 and 6.51 cm, respectively, and the growth coefficients of males and females were 0.71 and 0.81, respectively. The snout-vent length (SVL), head length, and body mass of males were all positively correlated with their age, but female age did not show a significant relationship with any physical parameter. The tail depth, body mass, and condition factors (SVL/body mass $\times$ 100) of both males and females were negatively related with the order of entrance to the breeding pond. The head width and SVL of males were also negatively correlated with the order of entrance, but the SVL of females was positively related with the order of entrance. These results suggest that physical parameters are more important determinants of breeding migration patterns than age. We discuss which of two hypotheses, the mate opportunity hypothesis and the susceptibility hypothesis, is better able to explain the order of entrance to breeding ponds for male and female H. leechii.

• Korea journal of population studies
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• v.24 no.2
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• pp.179-206
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• 2001

This study examines degree of fairness migrant workers in Korea feel with their wages in comparison to those of their homeland and Korean workers who do the same job in Korea as theirs, and what factors affect the feelings. For the study, 742 migrant workers from China, Vietnam, Philippines, and Indonesia employed by manufacturing firms in Seoul and Gyenggi areas were surveyed. The results show that most migrant workers in Korea feel unfair about their wages, and the feeling of unfairness appears more strongly when comparing with the Korean workers than with their homeland workers. The effectiveness of variables affecting fairness also varies according to the object of comparison: in comparison to homeland workers, age, sex, monthly income before migration, money spent for employment, and satisfaction with working conditions are significant: in comparison to Korean workers, ethnicity, sex, legal status, satisfaction with working conditions are significant.

• Korea journal of population studies
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• v.19 no.2
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• pp.77-105
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• 1996

The rural problems which we are facing start from the extremely small sized population and the skewed population structure by age and sex. Thus we analyzed the change of the rural population. And we analyzed the recent return migration to the rural areas by comparing the recent in-migrants with out-migrants to rural areas. And by analyzing the rural village survey data which was to show the current characteristics of rural population, we found out the effects of the in-migrants to the rural areas and predicted the futures of rural villages by characteristics. The changes of rural population composition by age was very clear. As the out-migrants towards cities carried on, the population composition of young children aged 0~4 years was low and the aged became thick. The proportion of the population aged 0~4 years was 45.1% of the total population in 1970 and dropped down to 20.4% in 1995, which is predicted to become under 20% from now on. In the same period(1970~1995), the population aged 65 years and over rose from 4.2% to 11.9%. In 1960, before industrialization, the proportion of the population aged 0~4 years in rural areas was higher than that of cities. As the rural young population continuously moves to cities it became lower than that in urban areas from 1975 and the gap grew till 1990. But the proportion of rural population aged 0~4 years in 1995 became 6.2% and the gap reduced. We can say this is the change of the characteristics of in-migrants and out-migrants in the rural areas. Also considering the composition of the population by age group moving from urban to rural area in the late 1980s, 51.8% of the total migrants concentrates upon age group of 20~34 years and these people's educational level was higher than that of out-migrants to urban areas. This fact predicted the changes of the rural population, and the results will turn out as a change in the rural society. However, after comparing the population structure between the pure rural village of Boeun-gun and suburban village of Paju-gun which was agriculture centered village but recently changed rapidly, the recent change of the rural population structure which the in-migrants to rural areas becomes younger is just a phenomenon in the suburban rural areas, not the change of the total rural areas in general. From the characteristics of the population structure of rural village from the field survey on these villages, we can see that in the pure rural villages without any effects from cities the regidents are highly aged, while industrialization and urbanization are making a progress in suburban villages. Therefore, the recent partial change of the rural population structure and the change of characteristics of the in-migrants toward rural areas is effecting and being effected by the population change of areas like suburban rural villages. Although there are return migrants to rural areas to change their jobs into agriculture, this is too minor to appear as a statistic effect.

• Korea journal of population studies
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• v.18 no.2
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• pp.70-97
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• 1995

The main purpose of this paper is to analyze the trend of urbanization and population distribution in North Korea. Although North Korean data lack comparable details, attention has been given to the comparison of urban system between North and South Korea. In North Korea, the pace of urbanization was most rapid just after the Korean War, from 1954 to 1960. However, the pace slowed down markedly in the early 1970s and has remained sluggish since then. North Korea is currently much less urbanized than South Korea. As specific features of urbanization in North Korea, emergence of new cities along inland borders, prominence of intermediate-sized cities, and sudden population growth of major cities due to boundary expansion are stressed. Available demographic data also indicate an overwhelming primacy of Pyongyang Municipality in the urban system, and rapid growth of satellite cities in the west-central region. It appears that, in North Korea, urbanization process has been a product of the government's development policies rather than individual's socioeconomic motivation to migrate urbanward. Finally, migration issues after unification of the Korean Peninsula and related problems are discussed in this study.