• Journal of the Korean association of regional geographers
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• v.16 no.5
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• pp.590-609
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• 2010

The purpose of the study is to propose and evaluate Exploratory Spatial Data Analysis(ESDA) methods for examining age-specific population migration characteristics. First, population migration pyramid which is a pyramid-shaped graph designed with in-migration, out-migration, and net migration by age (or age group), was developed as a tool exploring age-specific migration propensities and structures. Second, various spatial statistics techniques based on local indicators of spatial association(LISA) such as Local Moran''s $I_i$, Getis-Ord ${G_i}^*$, and AMOEBA were suggested as ways to detect spatial dusters of age-specific net migration rate. These ESDA techniques were applied to age-specific population migration of Daegu Metropolitan City. Application results demonstrated that suggested ESDA methods can effectively detect new information and patterns such as contribution of age-specific migration propensities to population changes in a given region, relationship among different age groups, hot and cold spot of age-specific net migration rate, and similarity between age-specific spatial clusters.

• Journal of Radiation Protection and Research
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• v.46 no.4
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• pp.170-177
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• 2021

Background: The International Commission on Radiological Protection is preparing to provide reference dose coefficients for environmental radioiodine intake based on newly developed age-specific biokinetic models. However, the biokinetics of iodine has been reported to be strongly dependent on the dietary intake of stable iodine; for example, the thyroidal uptake of iodine may be substantially lower in iodine-rich regions than in iodine-deficient regions. Therefore, this study attempted to establish a system of age-specific thyroid dose estimation for South Koreans, whose daily iodine intakes are significantly higher than that of the world population. Materials and Methods: Korean age-specific biokinetic parameters and thyroid masses were derived based on the previously developed Korean adult model and the Korean anatomical reference data for adults, respectively. This study complied with the principles used in the development of age-specific biokinetic models for world population and used the ratios of baseline values for each age group relative to the value for adults to derive age-specific values. Results and Discussion: Biokinetic model predictions based on the Korean age-specific parameters showed significant differences in iodine behaviors in the body compared to those predicted using the model for the world population. In particular, the Korean age-specific thyroid dose coefficients for ¹²⁹I and ¹³¹I were considerably lower than those calculated for the world population (25%-76% of the values for the world population). Conclusion: These differences stress the need for Korean-specific internal dose assessments for infants and children, which can be achieved by using the data calculated in this study.

• Journal of Preventive Medicine and Public Health
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• v.28 no.3 s.51
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• pp.651-662
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• 1995

In Korea there is no specific method of age adjustment in noise induced hearing loss(NIHL). We attempted the age adjustment to understand the effects of age on the diagnosis of NIHL. We used the International Standard Organization 1999 as an age adjustment method. We used the 1, 617 otologically normal person's hearing data from a health examination center, and 206 workers diagnosed as NIHL. We concluded as follows; 1. The ISO 7029 function used for age specific hearing loss is not suited to Korean people. 2. The mean of age specific hearing loss is 11.0 6.2dB and the older of age, the more decrease on hearing loss, especially in 4000Hz. 3. The difference of NIHL between before age adjustment and after age adjustment in the 3rd decade is 5.4dB, in the 4th decade is 6.7dB, in the 5th decade is 8.5dB, in the 6th decade is 10.4dB, and in the 7th decade is 12.9dB. The older, the more is the difference. 4. After age adjustment, the number of workers diagnosed as NIHL decreases to 60% of unadjusted.

• Clinical and Experimental Pediatrics
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• v.65 no.3
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• pp.108-114
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• 2022

The Japanese encephalitis (JE) virus is the leading cause of vaccine-preventable encephalitis in Asia. Since the introduction of a universal JE vaccination program and urbanization of Korea, the incidence of JE has dramatically decreased in Korea. However, recent JE cases have occurred, predominantly among unvaccinated adults and with a shift in age distribution. Here we aimed to review the changes in age-specific JE seroprevalence over time and discuss the implications of JE vaccination programs in Korea. Following the last epidemic in 1982-1983, mandatory vaccination for all children aged 3-15 years was conducted annually until 1994. However, JE has reemerged, predominantly affecting unvaccinated adults aged 40 years or older and demonstrating a shift in age distribution toward older populations. The age-specific seroprevalence of the JE virus in Korea has changed noticeably over time. Seropositivity in children and adolescents increased from 10%-59% in the 1970s to 90%-92% in the 1980s after the implementation of the JE vaccination program and increased further to 98% in 2012. No age-specific difference in the seroprevalence of JE was found, and appropriate levels of immunity to JE were maintained for all age groups. Continuous surveillance of the seroprevalence of JE is essential to establish a proper immunization policy in Korea.

• Korea journal of population studies
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• v.29 no.2
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• pp.53-88
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• 2006

The major aim of this paper is to develop a hypothetical set of age-specific fertility rates which are logically derived and reasonably accurate in the projection of future population. The first procedure is to select a generalized log-gamma distribution model, which includes Coale-McNeil nuptiality model, in order to estimate and project a set of age-specific fertility rates by birth cohort and birth order. The second is to apply the log-gamma model with an empirical adjustment to the actual data to estimate and project the future fertility rates for relatively young birth cohorts who did not complete their reproductive career. This study reconstructs or translates a set of cohort age-specific fertility rates into a set of period age-specific fertility rates which must be hypothesized in order to establish the broader framework of future population projection. For example, the fertility at age 20 in the year of 2020 is the fertility at age 20 for the cohort born in 1990, while the fertility at age 21 in the year of 2020 is the fertility at 21 for the cohort born in 1989. In turn, once a set of age-specific fertility rates for the cohorts who were born up to the year of 2010, it is possible for one to establish an hypothetical set of period age-specific fertility rates which will be needed to project the future population until the year of 2055. The difference in the hypothetical system of age-specific fertility rates between this study and the 2005 special population projection comes from the fact that the fertility estimation/projection model used in this study was skillfully exploited to reflect better actual trend of fertility decline caused by rise in marriage age and increasing proportion of those who remain single until their end of reproduction. In this regard, this paper argues that the set of age-specific fertility rates derived from this study is more logical and reasonably accurate than the set of those used for the 2005 special projection. In the population projection, however, the fundamental issue of the hypothetical setting of age-specific fertility rates in relation to the fertility estimation/projection model is about how skillfully one can handle the period effects. It is not easy for one to completely cope with the problem of period effects except for the a minor period adjustment based on recent actual data, along with the given framework of a cohort-based fertility estimation/projection model.

• Pediatric Infection and Vaccine
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• v.3 no.2
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• pp.175-184
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• 1996

Purpose : This study was intended to measure seropositivities and the levels of mumps- and rubella-specific IgG of MMR vaccinees over 17 months of age in Korea. Materials and Methods : From June 1994 to April 1995 we obtained sera from visitors of well baby clinic and patients in Korea University Hospital, who were MMR vaccinees over 17 months of age and had no evidence of immunodeficiency. These 275 study population include 145 males and 130 females. Mumps- and rubella-specific IgG antibody levels were measured by ELISA. Cut-off values for seropositivity were 20 GU(Gamma Unit) in mumps and 0.17 in rubella. Results : 1) As age increased, seropositivities of mumps-specific IgG increased significantly, being 69.0% in 1.5~2 year, 75.0% in 3~4 year, 76.0% in 5~6 year, 90.0% in 7 year, 100% in 8 year, 96.9% in 9 year, 97.4% in 10 year, 97.4% in 11 year, and 96.6% in 12 year of age(p<0.001). 2) As age increased, the levels of mumps-specific IgG antibody(mean${\pm}$standard deviation, GU) increased significantly, being $64.9{\pm}66.5$ in 1.5-2 year, $117.7{\pm}126.4$ in 3~4 year, $152.3{\pm}147.1$ in 5~6 year, $194.3{\pm}168.2$ in 7 year, $258.1{\pm}190.6$ in 8 year, $193.1{\pm}130.1$ in 9 year, $225.7{\pm}119.6$ in 10 year, $220.7{\pm}114.3$ in 11 year, and $222.3{\pm}127.1$ in 12 year of age(p<0.001). There was positive correlation between age and mumps-specific antibody level (r=0.3282, p<0.001). 3) As age increased, seropositivities of rubella-specific IgG decreased significantly, being 72.4% in 1.5~2 year, 75% in 3~4 year, 72% in 5~6 year, 60% in 7 year, 44.4% in 8 year, 40.6% in 9 year, 28.2% in 10 year, 23.1% in 11 year, and 17.2% in 12 year of age(p<0.001). 4) As age increased, rubella-specific IgG decreased significantly, being $0.462{\pm}0.356$ in 1.5~2year, $0.438{\pm}0.306$ in 3~4 year, $0.287{\pm}0.179$ in 5~6 year, $0.204{\pm}0.139$ in 7 year, $0.189{\pm}0.153$ in 8 year, $0.124{\pm}0.121$ in 9 year, $0.093{\pm}0.114$ in 10 year, $0.104{\pm}0.135$ in 11 year, and $0.080{\pm}0.001$ in 12 year of age(p<0.001). There was negative correlation between age and rubella-specific IgG titer (r=-0.551, p<0.001). Conclusions : Eventhough seropositivities and the level of mumps-specific IgG increased as age increased, they are not enough to prevent mumps infection in 1.5 to 6 years of age. Seropositivities and the level of rubella-specific IgG decreased as age increased. Appropriate change in vaccine schedule may be needed to decrease the risks of mumps and rubella infection.

• Asian Pacific Journal of Cancer Prevention
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• v.15 no.6
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• pp.2461-2464
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• 2014

Background: Cancer accounts for 12.6% of total deaths in the world (just after heart disease). Materials and Methods: Frequency and age-specific incidence rates of breast and gynecologic cancers in Iran are calculated based on the dataset of the National Cancer Registry of Iran in 2005. Results: Gynecologic and breast cancer accounted for 7.6% and 25.6% of total cancer cases, respectively. Ovarian cancer was the most frequent gynecologic cancer followed by endometrium. Endometrial cancer revealed the highest age specific incidence rate followed by ovary (after 59 years). Conclusions: Regarding disease burden, breast and gynecologic cases account for 33.4% of total cancer patients. The age specific incidence rate is a useful guide in epidemiologic and future plans.

• Korean Journal of Child Studies
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• v.11 no.2
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• pp.82-97
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• 1990

The purpose of this study was to investigate (1) the developmental level of children's concept of gender by age and sex. (2) children's sex-specific behaviors by age and sex, and (3) children's sex-specific behaviors by developmental level of gender constancy. The subjects were 164 children (forty 3-year-olds, forty-three 5-year-olds, forty 7-year-olds and forty-one 9-year olds) with nearly equal numbers of boys and girls. They were selected from two kindergartens and one elementary school. A quasi experiment was carried out with the procedures described by Slaby and Frey (1976) to measure children's developmental level of the concept of gender constancy. Two experiments were carried out to observe children's sex-specific behaviors: one for children's toy choice behavior and the other for children's interaction with their peers. Statistical methods adopted for data analysis were frequencies. percentiles, mean. and $X^2$. It was found that children's sex-specific behaviors were different according to their developmental level of gender constancy. Children's developmental level of gender constancy was significantly different according to their age, but there was no difference according to their sex. Children's toy-choice behavior was significantly different according to their age and sex. Children's sex-specific behaviors were significantly different according to their concept of gender constancy.

• Journal of Korean Academy of Nursing
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• v.37 no.1
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• pp.44-51
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• 2007

Purpose: The purpose of this study was to compare suicide mortality by region in South Korea. Method: Suicide mortality differentials were calculated for several mortality indicators by geographical regions from raw data of the cause of death from KNSO. Results: The results are as follows; the Crude suicide death rate was 22.63 per 100,000. The highest was in Kangwon showing 37.84% whereas, Chungnam, and Jeonbuk followed after. Suicide was 4.4% of all causes of death, but Inchon and Ulsan showed a higher proportion. The male suicide death rate was 31.12 per 100,000 and females 14.09. The ratio of gender suicide mortality was 2.21, per 100,000 and was the highest in Jeju. For age-specific suicide death rates, the rate increased as age advanced, showing 2.33 per 100,000 in 0-19years, 18.68 in 20-39, 30.48 in 40-59, 63.33 in 60 years and over. In Ulsan, Kangwon, and Inchon, age-specific suicide death rates of the 60 and over age group were higher than other regions, Daegu, Busan, and Kangwon showed a higher age-specific suicide mortality of the 40-59 age group, and Kangwon, Jeonnam, and Chungnam had a higher age-specific suicide mortality of the 20-39 age group. Conclusions: Suicide mortality differed by region. These results can be used for a regional health care plan and planning for suicide prevention by regions.

• Structural Engineering and Mechanics
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• v.52 no.1
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• pp.97-113
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• 2014

In the present work appropriate concrete material models have been proposed to predict drying shrinkage and specific creep of High-performance concrete (HPC) using Artificial Neural Network (ANN). The ANN models are trained, tested and validated using 106 different experimental measured set of data collected from different literatures. The developed models consist of 12 input parameters which include quantities of ingredients namely ordinary Portland cement, fly ash, silica fume, ground granulated blast-furnace slag, water, and other aggregate to cement ratio, volume to surface area ratio, compressive strength at age of loading, relative humidity, age of drying commencement and age of concrete. The Feed-forward backpropagation networks with Levenberg-Marquardt training function are chosen for proposed ANN models and same implemented on MATLAB platform. The results shows that the proposed ANN models are more rational as well as computationally more efficient to predict time-dependent properties of drying shrinkage and specific creep of HPC with high level accuracy.