• The Korean Journal of Ecology
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• v.16 no.3
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• pp.305-316
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• 1993

Stands profiles, yearly changes in growth of annual rings, age and diameter structure, and spatial distribution pattern of individuals in the Pinus densiflora stands around the Yeocheon industrial complex were investigated. Growth of annual ring in Pinus densiflora, which survived when vegetation of this area was damaged by air pollutants, was suppressed for about 10 years since 1974 when factories in this area began to operate, but since then such suppressed growth tended to be recovered. It was supposed that the suppresed growth was originated from air pollution and that improvement of growth since the suppressed period was due to the release from competition with them by death of neighbouring trees and the resuction of the amount of air pollutants. Physiognomy of Pinus densiflora stands showed mosaic pattern composed of different patches. Spatial distribution pattern of individuals an stand profiles were similar to those of Pinus densiflora stands regenerated after natural and artificial disturbances. In an age distribution diagram, age of Pinus densiflora population ranged from 1 to 33 years, Among these individuals were recrited corresponded to the suppresed period of growth of annual ring in Pinus densiflora survived when the vegetation was damaged by air pollution. On the other hand, from the result of analysis of frequency distribution diagram of diameter, it was postulated that even if whis Pinus densiflora community can be maintained as it is for the time being, it might be changed to Quercus community with the lapse of time.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.22
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• pp.10021-10025
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• 2014

Background: The study aimed to describe the age distribution of breast cancer diagnosis among Chinese females for comparison with the United States and the European Union, and provide evidence for the screening target population in China. Materials and Methods: Median age was estimated from hospital databases from 7 tertiary hospitals in China. Population-based data in China, United States and European Union was extracted from the National Central Cancer Registry, SEER program and GLOBOCAN 2008, respectively. Age-standardized distribution of breast cancer at diagnosis in the 3 areas was estimated based on the World Standard Population 2000. Results: The median age of breast cancer at diagnosis was around 50 in China, nearly 10 years earlier than United States and European Union. The diagnosis age in China did not vary between subgroups of calendar year, region and pathological characteristics. With adjustment for population structure, median age of breast cancer at diagnosis was 50~54 in China, but 55~59 in United States and European Union. Conclusions: The median diagnosis age of female breast cancer is much earlier in China than in the United States and the European Union pointing to racial differences in genetics and lifestyle. Screening programs should start at an earlier age for Chinese women and age disparities between Chinese and Western women warrant further studies.

• Asian Journal of Business Environment
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• v.9 no.4
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• pp.23-28
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• 2019

Purpose - With rapid population aging in Korea, changes in the population structure will result in a rise in the fiscal burden. This paper investigates the effects of population aging on fiscal spending based on Korea's province data and country panel data from the OECD. Research design, data, and methodology - We use province-level fiscal data from Local Finance Integrated Open System and the Korean Statistical Information Service and also collect country panel data from the OECD. To investigate the relationship between population aging and fiscal expenditures, our analysis uses the fixed effects model. Results - The empirical analysis based on Korean local finance and country panel data show that population aging has a positive impact on social welfare expenditures and it also has a positive impact on spending related to children and the elderly, implying that population aging may lead to an increase in fiscal spending via an increase in social welfare expenditures and spending related to children and the elderly. Conclusion - These empirical results suggest that countries like Korea that expect to experience rapid population aging need to pay more attention to prepare for the expected increase in age-related spending in the near future.

• Animal cells and systems
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• v.14 no.4
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• pp.315-322
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• 2010

We studied and compared the age structure, body size, and growth rates of field populations of two Korean salamander species (Hynobius yangi and Hynobius quelpaertensis) to elucidate important aspects of basic population dynamics of these two endemic Hynobius species. In both populations, females were sexually mature at three years of age, while H. yangi and H. quelpaertensis males matured at two and three years of age, respectively. Both males and females of H. yangi and H. quelpaertensis attained a maximum age of 11 years and 10 years, respectively. In both species, the snout-vent length (SVL) and body weight (BW) of the females were greater than those of the males. The SVL, BW, and asymptotic SVL of both male and female H. yangi were smaller than those of H. quelpaertensis. The adult growth rates after sexual maturation of male and female H. yangi were lower than those of H. quelpaertensis, possibly resulting in the smaller body size of the former, although overall growth coefficients were not significantly different between the two species. We also compared the age structure and growth rates of three Korean and three Japanese species of Hynobius.

• Korea journal of population studies
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• v.21 no.2
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• pp.58-82
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• 1998

It is usually proposed that job security of old age workers is hampered by the structure of wage increasing with age. This paper sets forth a model to comprehend the characteristic of the old age workers' labor market and policy implications derived from it. In order to stimulate demand for old age workers, policy initiatives should be taken as follows : the wage criteria should be simplified which apply differently from one institution to other; incentives relatively favorable for employing old age workers' in manufacturing sector should be also given to service sectors; employment subsidy or other tax incentives should be given for labor contract after the retirement age; licensing and evaluation system for job ability should be introduced based on occupation & job analysis. To lower the reservation wage of workers, mortgage loan for house and long-term low interest loan for tuition fees should be developed together with stabilization of housing cost. Wedding culture which requires high expense should be amended. Above all, it is necessary to install reasonable social security system. Policy orientation should also pay attention to reduce labor supply of the old aged via aiding old age workers' firm opening and voluntary civil service together with developing various honor programs for members of civil corps.

• Korea journal of population studies
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• v.15 no.2
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• pp.15-59
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• 1992

After world war II Japanese life expectancy has been improved remarkably, and reached the highest level in the world around late 1970's. The life expectancy of Korean has also shown tremendous improvement in recent years with about 20 year's gap from the Japanese. The reason of rapid improvement of life expectancy can be explained by changes in the structure of cause of death due to health system, living standard, social welfare, health behavior of individuals and so on. Korean in Japan is placed under different situations from both Korean in Korea and Japanese in these regards, and expected to show different picture of cause of death pattern. The objective of this study is the comparision of changing patterns of cause of death of three population groups, Korean in Japan, Korean in Korea and Japanese, and to investigate the reasons which effect to the structural difference of mortality cause with special emphasis on health ecological aspects. One of the major limitations of the Korean causes of death statistics is the under-registration which ranges about 10% of the total events, and inaccuracy of the exact cause of death. Some 20% of registered deaths were unable to classify by ICD. However, it is concluded that the Korean data are evaluated as sufficient to stand for over-viewing of trends of cause of death pattern. The evaluation is done by comparing data from registration and field survey over the same population sample. Population data of Korean in Japan differ between two sources of data; census and foreigner's registration. Correction is done by life table method under the assumption that age-specific mortality pattern would accord with that of the Japanese. The crude death rate was lowest among Korean in Japan, 5.7 deaths per 1,000 population in 1965. The crude death rates of Korean in Japan and Japanese are increasing recently influenced by age structure while Korean in Korea still shows decreasing tendency. The adjusted death rate is lowest among Japanese, followed by Korean in Japan, and Korean in Korea. The leading causes of death of Korean in Korea until 1960's was infectious diseases including pneumonia and tuberculosis. The causes of death structure changed gradually to accidents, neoplasm, hypertensive disease, cerebro-vascular disease in order. The main difference in cause of death between Korean and Japanese if high rate of liver diseases and diabetes for both Korean in Japan and Korea. A special feature of cause of death among Korean in Korea is remakably high rate of hypertensive disease, which is assumed to be caused by physicians tendency in choosing diagnostic categories. The low ischemic heart disease and high vasculo-cerebral disease are the distinctive characteristic of the three population groups compared to western countries. Specific causes of death were selected for detailed sex, age and ethnic group comparisons based on their high death rates. Cancer is the cause of death which showed most dramatical increase in all three population groups. In Korea 20.1% of all death were caused by cancer in 1990 compared with 10.5% in 1981. Cancer of the liver is the leading cause of cancer death among Korean in Japan for both sexes, followed by cancer of the lung and cancer of the stomach, while that of Korean in Korea is cancer of the stomach, followed by cancer of the liver and cancer of the lung for male. Causes of infant mortality were examined among the three population groups since 1980 on yearly bases. For both Japanese and Korean in Japan, leading cause of death ranks as conditions originating in the perinatal period, congenital anomalies, accidents and other violent causes. Trends since 1980 for these two population groups in the leading cause of infant mortality showed no changes. On the contrary, significant changes in leading cause of death structure in Korea were observed : the ranking of leading cause of death in 1981 were congenital asnomalies, pneumonia bronchitis, infectious disease, heart disease, conditions originating in the perinatal period, accident and other violent causes ; in 1990 the ranking shifted to congenital anomalies, accident, pneumonia bronchities, conditions originating in the perinatal period, infectious disease. The mortality rate by congenital anomalies in Korea continuously grew than any other causes. Larger increase ocurred during the 1990's

• Journal of the Society of Disaster Information
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• v.10 no.3
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• pp.466-480
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• 2014

In addition to aging social problem, the problem of older age structure ratio in the fire service organization playing the leading role of the disaster response activities is also expected to be this serious situation. In the case of Seoul fire fighting organization, it is expected that the ratio of over the age 50 reaches 31% or 40% between from 10 to 15 years later from now on, but this will be a serious problem in the fire fighting personnel needing a healthy body and physical strength in the disaster situation unlike the civil servants of general staff. Therefore, the purpose of this study is to take measures that can adapt to a new disaster environment of Increasing proportion of the elderly population by presenting the criteria of age limit of fire fighting field activities to analyze the relevance of the ability to perform on-site activities and age of Seoul fire civil servants, by using three analysis criteria.

• Journal of Preventive Medicine and Public Health
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• v.11 no.1
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• pp.41-48
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• 1978

To examine the result of the government Medical Aid Program which began in January, 1977 as a part of social security policy implementation, all the medical records of the clients and official statistics in the year were analysed. The specific objectives this study pursues include the magnitudes and patterns of morbidity and utilization, and the characteristics of clients. One Korean rural area, Koje county was selected as the study area and subsequently all the clinics and hospitals assigned to work out the Aid Program are the subjects for the survey. A brief summary of the sutdy results as follows: a. The clients of Koje county are 6.4% of the total population in the area, more than the average percentage of the clients in Korea. It reflects on low level of economic status of the residents of the area. b. The population structure of the clients indicates that the large proportions of young and old age group are overwhelming, while the middle age group share very small portions. c. The utilization rates for primary care are 2.0 persons, 11.6 visits and 22.6 treatment days per 100 persons per months. Annual hospitalization is rated as 13.7 cases and 164 days per 1,000 persons, The utilization rates are slightly lower than those expected rates during planning period but eventually become higher than those of general population in rural Korea. d. The factors which influence the utilization rates are identified with client group (low income vs indigent), age and sex. e. The utilization pattern for primary care demonstrates seasonal variation similar to the pattern of general rural population in the low income group, but none in the indigent group. f. The most common diseases revealed at the primary care clinics are the acute respiratory infection (26.9%), acute gastritis (10.8%), skin and subcutaneous infection (6.8%). The cases of acute conditions are outnumbered than the cases of chronic condition. 8. The clinics, hospitals and other related health institutions are well cooperated in dealing health care services in their own capacities. Considering the above results Medical Aid Program generated satisfactory results at least in the utilization aspect.

• Korea journal of population studies
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• v.9 no.2
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• pp.53-66
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• 1986

This study was carried out to determine the mortality level and it's related demographic factors in Korea since 1942. In order to clarify the changes in structure of mortality and the causes of death, the indices such as Crude Death Rate(CDR) or Life Expectancy at Birth were used. The author examined the mortality levels and major causes of death and performed the relevant demographic analysis. The followings are the summary of this study: 1. The CDR declined rapidly till 1960's. Such improvement slowed down from 1960's to mid 1970's and stabilized afterwards. It was due to the change of age composition, namely, the increase of aging population. 2. The Life Expectancy at Birth increased rapidly till mid 1960's. But elongation of the Life Expectancy slowed down after then. Especially in female, it slowed down more. 3. Changing patterns of major causes of death summarize that, till 1960's infectious diseases were major causes of death, but recently non-infectious diseases like chronic degenerative diseases became more prevalent. 4. The elongation of Life Expectancy at Birth till mid 1960's was mainly resulted by $_4{q}_1$. But the major contributing factor of the improvement in Life Expectancy at Birth in female is he reduction of $_$\infty${q}_{50}$ recently. In male, the improvement in Life Expectancy at Birth is due to the reduction of $_1{q}_0$. recently. 5. The age-sex-specific mortality rates revealed that $_n{q}_x$ declined in common throughout the period, even though there exists some variability of their ranges as age changes. Consequently, this study seems to suggest that the demographic transition in Korea occurred between late 1960's and early 1970's. In other words, the rapid change before late 1960's was eased in early 1970's. The slow change in this period caused a stabilizing pattern. Therefore, the population change is expected to be stabilized continuously.

• Korean Journal of Environment and Ecology
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• v.38 no.2
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• pp.169-177
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• 2024

This study investigated whether population dynamic analysis based on the height characteristics of Abies nephrolepis was feasible. It was necessary because existing population dynamic analyses based on age and diameter at breast height (DBH) made it difficult to reflect the slow growth characteristics of Abies nephrolepis in harsh environments of high altitudes. The limitations of population dynamics analysis based on the age and DBH distribution of Abies nephrolepis in Seoraksan, Odaesan, and Taebaeksan National Parks, where Abies nephrolepis populations are representative, were verified, and the characteristics of height growth were investigated to comprehensively analyze whether a vertical structure based on height could reveal the population dynamics. The result of this study showed some limitations in understanding the population dynamics of Abies nephrolepis based on age distribution due to practical difficulties in sampling all trees and variations in age distribution within the same community depending on factors such as light conditions. Moreover, it was challenging to differentiate the distribution of DBH classes at fine levels, making it difficult to reflect the rapid growth characteristics of Abies nephrolepis when light conditions become suitable after prolonged stays in smaller DBH classes under shade conditions. However, a comprehensive analysis of the height characteristics of Abies nephrolepis revealed that the density corresponding to the population dynamic characteristics of Abies was high and adequately reflected the predominant tree death at similar height stages, as well as the U-shaped population dynamics at the lower stratum. Moreover, it was possible to identify a transition point in height values under shaded conditions, where the annual growth of Abies nephrolepis individuals in the lower stratum increases significantly, indicating that Abies nephrolepis individuals can escape from competition with other shrubs and undergo vigorous growth only at this height level. Therefore, this study confirmed that a vertical structure based on height can be utilized to understand the population dynamics of Abies nephrolepis in high altitudes, and it is expected that future studies on height characteristics can intuitively reveal the maintenance status of Abies nephrolepis populations in the field.