• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.66.4-67
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• 2016

Our recent investigation (Lee et al. 2015) suggests that the presence of double red clump in the Milky Way bulge is another manifestation of multiple populations observed in halo globular clusters. The origin of Helium enhancement in the 2nd generation population (G2), however, is not yet fully understood. Here we investigate the origin of this super-Helium-rich population in the framework of self-enrichment scenario. We find that chemical enrichments and pollutions by asymptotic giant branch stars and winds of massive rotating stars can naturally reproduce the observed Helium enhancement. The Helium to metal enrichment ratio appears to be ${\Delta}Y/{\Delta}Z=6$ for G2, while the standard ratio, ${\Delta}Y/{\Delta}Z=2$, is appropriate for G1, which is probably enriched mostly by typeII supernovae.

• The Journal of Fisheries Business Administration
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• v.51 no.1
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• pp.67-79
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• 2020

The purpose of this study is to propose a policy improvement plan by analysis of the extinction risk factors reflecting the specificity of fishing villages, fishing village support policies, and settlement conditions of fishing villages as one of the solutions to the immediate problem of fishing village extinction. The results of the study show the higher the level of number of fishing ports, number of returning rural population, and housing diffusion rate, the dependent variable extinction risk index was a positive effect while vacant house ratio and aged house ratio was analyzed to be in was a negative (-) relationship with the dependent variable.The policy implications through this study were to prepare an effective policy to reduce the risk of extinction, to improve urgent settlement conditions, and to prepare a condition to convert returning rural population into fishery population.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2000.07a
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• pp.5-8
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• 2000

The population density of excited species in dc, rf and laser ablation plume plasmas has been measured using laser absorption spectroscopy. It was shown that, when the plasma was modulated by on and off with, the sensitivity and signal to noise (S/N) ratio became high. For example, the atomic O(3$^{5}$ S$^{o}$ $_2$) Population density, No* in $O_2$/He mixtures was obtained by the highest S/N ratio at a frequency of 2.7kHz. In a 20Torr room air, the lowest No* level to be detectable was shown to be an order of 10$^{7}$ cm$^{-3}$ . The population densities of resonance Ar(1S$_2$) and Xe(1S$_4$) levels were also measured in barrier discharges and laser ablation plasmas.

• Communications for Statistical Applications and Methods
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• v.26 no.1
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• pp.11-25
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• 2019

The present paper utilizes auxiliary information to neutralize the effect of non-response for estimating the population mean. Improved ratio type estimators for population mean have been proposed and their properties are studied. These estimators are suggested for both single phase sampling and two phase sampling in presence of non-response. Empirical studies are conducted to validate the theoretical results and demonstrate the performance of the proposed estimators. The proposed estimators are shown to perform better than those used by Cochran (Sampling Techniques (3rd ed), John Wiley & Sons, 1977), Khare and Srivastava (In Proceedings-National Academy Science, India, Section A, 65, 195-203, 1995), Rao (Randomization Approach in Incomplete Data in Sample Surveys, Academic Press, 1983; Survey Methodology 12, 217-230, 1986), and Singh and Kumar (Australian & New Zealand Journal of Statistics, 50, 395-408, 2008; Statistical Papers, 51, 559-582, 2010) under the derived optimality condition. Suitable recommendations are put forward for survey practitioners.

• Journal of Environmental Impact Assessment
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• v.27 no.4
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• pp.394-401
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• 2018

Tendency in ratio of biotope area of environmental impact assessment (EIA) according to population, location, project type, and total project area was analyzed by type of the projects. According to EIA, biotope area ratio is the ratio of the weighted biotope areas and total project area. biotope area is important to resident's health and quality of their life. Ministry of Environment recommends to meet the biotope area ratio standard presented by each project type. The analysis is based on 4 types of project, urban development, industrial comlpex deveopment, tourism development, and waste and sewerage treatment facility, and 55 data extracted from them. It is needed that new standard that the population is reflected, adjustment that region and frequency are considered, and regulation strengthening according to achievement of 'the minimum achievable goals' to improve biotope area policy. The research includes more data and improvements of specific system are needed as a further research.

• Korean Journal of Health Education and Promotion
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• v.27 no.1
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• pp.1-8
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• 2010

Objectives: Human papillomavirus (HPV) infection is highly associated with cervical cancer. So, the modification of the risk factors of HPV infection is essential for prevention of cervical cancer. This study was performed to evaluate the risk factors of HPV infection. Methods: HPV test of 12,337 study population conducted using Hybrid-Capture II assay(HC-II) and self-administered questionnaires were collected. The study population was people who visited hospital-based medical screening center from January to December 2007 and all were female employees or employees' partner. Results: In logistic regression analysis, smoking and alcohol drinking were significant factors, with odds ratios of 1.328 (95% CI 1.010~1.746) and 1.644 (95% CI 1.309~2.066), respectively. Nutritional supplements was also significant factor, which odds ratio was 1.161 (95% CI 1.004~1.343). Oral contraceptives was positive association with HPV infection (odds ratio 2.108; 95% CI 1.217~3.652), whereas condom was negative association (odds ratio 0.851; 95% CI 0.740~0.979). Conclusion: HPV Prevalence of 12,377 study population was 11.4%. Smoking, alcohol drinking, nutritional supplements and oral contraceptives were possible risk factors of HPV infection, and condom had possible preventive effect on HPV infection. Further prospective and comprehensive studies about HPV risk factors are required.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.36 no.2
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• pp.144-150
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• 2003

Reproductive biology and population dynamics of Latreutes planirostris were investigated on the south western waters of Korea from June 2001 to May 2002. This paper describes sex ratio, population growth, and reproductive aspects of Latreutes planirostris. Brood size was an isometric function of female carapace length. Based on dry weight, reproduction effort (mass of eggs/mass of female) averaged 0.23. Ovarian examination showed that there was significantly higher gonadosomatic index from May to September, with a peak in June. Statistical analysis revealed that the ovarian dry weight of females with eyed eggs was significantly higher than that of those with non-eyed eggs. This suggests that females were potentially consecutive breeders. Sex ratio showed that female is more numerous than male. Growth parameters mortality and recruitment were estimated by monthly length-frequency data. Growth parameters were estimated, using the seasonalized von Bertalanffy growth function model $(L\infty\;=\;12.70\;mm\;CL,\;K\;=\;0.87yr^{-1},\;C\;=\;0.96,\;WP\;=\;0.59)$. The recruitment pattern was twice a year.

• Korea journal of population studies
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• v.17 no.2
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• pp.98-115
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• 1994

This study is attempting to examine the possible determinants of the rise of the sex ratio at birth from 106 to 110 in past decade in Taiwan. The basic hypothesis for the sudden rise of the sex ratio at birth is due to a combination of prenatal sex determination and abortion. The reasoning for this hypothesis involves three types of considerations - motivation, norm, and access. The theory is evaluated by analyzing data from birth registration and a large and representative sampie of Taiwanese wives of childbearing age. The empirical data seem to support the theoretical preposition and the basic hypothesis that the rise of the sex ratio at birth in Taiwan is due to a combination of prenatal sex determination and abortion. There is striking evidence of son-preference in the rise of the sex ratio at birth in higher birth order. In 1990 the sex ratio was 119 for third births and 128 for fourth and fifth births compared to the expected 106. Also, the 1991 KAP data indicated that women who have only daughters but no any son are more likely to make prenatal sex screening and terminate their pregnancies in male live births at higher birth order. Obviously, genetic diagnosis through chorionic villus sampling which was available in recent years was misused for prenatal sex determination and sex selective abortion.

• Journal of the Korean Statistical Society
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• v.27 no.3
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• pp.331-348
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• 1998

In this paper, we have proposed some robust Bayes estimators using ML-II priors as well as certain empirical Bayes estimators in estimating the finite population mean in the presence of auxiliary information. These estimators are compared with the classical ratio estimator and a subjective Bayes estimator utilizing the auxiliary information in terms of "posterior robustness" and "procedure robustness" Also, we have addressed the issue of choice of sampling design from a robust Bayesian viewpoint.

• KDI Journal of Economic Policy
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• v.26 no.1
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• pp.105-140
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• 2004

Korea is entering the class of aging population nations. This paper investigates the extent demographic factors and the aging population affect the saving rate, using an extended life-cycle/permanent-income hypothesis on saving. The results of the tests with Korean household survey data from 1977 to 2002 reveal that real saving rates increase when the duration of lifetime and per household real disposable income rise, and decrease when the growth rate of income and net worth-to-GDP ratio rises. The growth rate of per household real disposable income has negative effects, suggesting that households calculate their life cycle income in a forward looking manner. The elasticities with respect to a change in the lifetime horizon and the growth rate of per household income are 0.58 and -0.03, respectively. A one percent rise in the net worth to GDP ratio reduces the saving rate by 0.3 percent. A one percent rise in per household income increases it by 0.33 percent. The younger-age and the elder-age dependency ratios have insignificant effects on the household saving rate behavior. When Korean life expectancy rises, the private saving rate declines modestly and the government saving rate declines substantially. The economy's real net saving rate declines from 33 percent in 2002 to 30 percent by the year 2030.