• The Korean Journal of Nuclear Medicine
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• v.6 no.2
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• pp.1-6
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• 1972

• Journal of Radiation Protection and Research
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• v.3 no.1
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• pp.37-43
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• 1978

• Journal of the Korean Statistical Society
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• v.35 no.3
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• pp.331-341
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• 2006

An approximate distribution of the plug-in estimator of the squared coefficient of variation ($CV^2$) is derived by using Edgeworth expansions under general population models. Also bias of the estimator is investigated for several important distributions. Under the normal distribution, we proposed the new estimator for $CV^2$ based on median of the sampling distribution of plug-in estimator.

• Korea journal of population studies
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• v.17 no.2
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• pp.116-135
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• 1994

China's population and family planning program has heen successful. Women's fertility as measured by total fertility rate (TFR) has declined from 5.8 in 1970 to 2.3 in 1990, accordingly the annual crude birth rate(CBR) has declined from 34 per thousand in 1970 to 21 per thousand in 1989, and the annual natural growth rate from 2.6 percent in 1970 to 1.4 percent in 1989 (Coale and Chen, 1987; SSB, 1991; Gu, 1994). While this is indeed an astonishing achievement for a developing country to have its fertility down to replacement within a short period, some new issues emerging along with the rapid fertility decline require careful considerations. One of them is the uprising of the sex ratio at birth in China. The 1990 population census reported the sex ratio at birth in China of 113.8 in 1989, which is ohviously much higher than the acceptable level of normal ratio around 106. It has received since then a lot of tention in China and abroad, among demographic professionals and governmental agencies alike (Hull, 1990; Johansson and Nygren, 1991; Xuand Guo, 1991; Tu, 1993; Gu and Xu, 1994; among others). Based on the available demographic data and research results this paper will first have a review of the patterns and trends of sex ratio at birth in China, then turn to the immediate causes of abnormal sex ratio at birth and the determinants of the son preference, followed with a conceptual framework for understanding of the phenomenon, and finally the policy implications and recommendations will be discussed.

• The Korean Journal of Applied Statistics
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• v.33 no.1
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• pp.11-23
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• 2020

Sampling design should provide statistics to meet a given accuracy while saving cost and time. However, a large number of non-responses are occurring due to the deterioration of survey circumstances, which significantly reduces the accuracy of the survey results. Non-responses occur for a variety of reasons. Chung and Shin (2017, 2019) and Min and Shin (2018) found that the accuracy of estimation is improved by removing the bias caused by non-response when the response rate is an exponential or linear function of variable of interests. For that case they assumed that the error of the super population model follows normal distribution. In this study, we proposed a non-response bias adjusted estimator in the case where the error of a super population model follows the gamma distribution or the log-normal distribution in a business survey. We confirmed the superiority of the proposed estimator through simulation studies.

• The Journal of the Korean Society for Microbiology
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• v.9 no.1
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• pp.41-45
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• 1974

On day 2 after treatment of Lewis rat with 25mg of hydrocortisone, the cell number in the thymus was reduced to less than 10% of the matched control. By day 12 after hydrocortisone treatment the thymic cell population was recovered almost its original value and on day 24 after treatment the number of thymocytes was equivalent to that of normal thymocytes. The density distribution profile of hydrocortisone treated rats as compared with normal rats showed a marked decrease in the denser fraction D while the lighter fractions. (A plus B, and C) showed a considerable proportional increase. The proportion of dead cells in thymus suspension from hydrocortisone treated rats was higher than that from their normal counterparts. On separation, the dead cells accumulated selectively in the pellet and A fraction. The response of the thymocytes from hydrocortisone treated rats to PHA was increased compared to that from normal rats. Among the subpopulations, D fraction, which was relatively unresponsive in normal rats, showed a marked increase in PHA response and C fraction showed some increase in the response.

• Nutritional Sciences
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• v.7 no.1
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• pp.3-7
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• 2004

This study was performed to investigate the effect of a raw diet (RD) on blood glucose and immune function in non-diabetic (normal) and streptozotocin (STZ)-induced diabetic rats. Male Sprague-Dawley rats were assigned to four groups (normal control, normal RD, diabetic control and diabetic RD). The control groups and the RD groups were fed an AIN-diet and RD for four weeks, respectively. Weight gain was statistically lower in the RD groups than in the controls. Fasting plasma glucose was significantly lower in the diabetic RD group than in the diabetic control group. The $CD4^+$ T-cell population was higher along with the $CD4^+/CD8^+$ ratio of the mesenteric lymph nodes in the normal RD group compared to the other groups. It can be concluded that RD may reduce the plasma fasting glucose concentration in diabetic rats and improve mesenteric lymph node immune function in normal rats.

• Korean Journal of Community Nutrition
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• v.11 no.3
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• pp.317-326
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• 2006

To explore the relationship between weight status and food intake pattern, the Nutrition Survey results of the 2001 National Health and Nutrition Survey were analyzed. Dietary intake data of Korean adults aged 20 to 64. years who participated in the 2001 National Health and Nutrition Survey, was used along with their demographic data. Subjects were classified into 4 groups based on the BMI value of subjects: underweight, normal, overweight and obese. For male adults, obese subjects had significantly higher mean intake of energy, protein, carbohydrates, and fat than normal subjects. In addition, obese male adults consumed more animal foods, especially more meats, than normal subjects. However, females obese subjects did not show higher intake of energy or fat. Although obese male adults showed higher energy intake, calcium and iron intake per 1000 kcal was lower than normal adults. Average calcium intake in females was low; about 70% of RDA regardless of obesity level. In addition, riboflavin and Vitamin A intake was lower in overweight and obese female than in normal females. Percentage of subjects with low fruit and vegetable intake (< 400 g per day) was also high in female subjects. These results showed that food and nutrient intake patterns of obese population were different between male and female adults. These dietary intake patterns need to be considered in developing and implementing nutrition policy and intervention programs to prevent and control obesity. Moreover, the National Survey and monitoring system should be developed for continuous and effective investigation on the relationship between obesity and dietary intake.

• Korean Journal of Poultry Science
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• v.18 no.3
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• pp.151-159
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• 1991

As a part of investigation on causes of drop in egg production in domestic chicken breeding farm, bacteriological contamination on air, feed, drinking water and artificial insemination instruments of randomly selected three farms was surveyed. Total bacterial population in the air was very high in all of the chicken houses tested and was not significantly different among these farms . However, total bacterial counts in the air of the problem house having egg drop problem and colibacillosis was higher than normal house within the problem farm. Bacterial population in the assorted feed was low before or after administration on the normal farm while it was much more increased after administration than before administration on the problem farm. Bacterial population of the drinking water in the source of water supply was very low and has no differences among farms tested. Also, bacterial population in the normal farm was not significantly different between source of water supply and after administration. However, population of total bacteria and coliform bacteria after administration was increased. Bacterial population was much higher in the artificial insemination instrument of problem farm than normal farm. However, this bacterial population in the problem farm was decreased to those of normal farm after these instruments were sanitized.

• Journal of the Korean Data and Information Science Society
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• v.17 no.2
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• pp.291-300
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• 2006

In this research, the performance of widely used Bayesian estimators such as Bayes estimator, empirical Bayes estimator, constrained Bayes estimator and constrained empirical Bayes estimator are compared by means of a measurement under balanced loss function for the typical normal-normal situation. The proposed measurement is a weighted sum of the precisions of first and second moments. As a result, one can gets the criterion according to the size of prior variance against the population variance.