• International Journal of Human Ecology
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• v.14 no.2
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• pp.69-78
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• 2013

This study analyzed the changes in household consumption expenditure of retired households using Korean panel data. We compared the pre and post retirement-consumption levels in different consumption categories using panel data. Paired t-test showed that changes in the consumption patterns before and after retirement were not significant except for the households in the third net worth quartile. Analyzing the effect of retirement on the level of household consumption expenditure, this study found that the effect of retirement was not significant in overall, although retirement had a negative effect on the level of consumption expenditure among households in the lowest net worth distribution. Understanding changes in consumption patterns of retiring households provides important information to design social security policies.

• Communications for Statistical Applications and Methods
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• v.24 no.1
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• pp.15-27
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• 2017

This paper introduces a two-parameter discrete distribution based on a continuous two-parameter bathtub distribution. It is the only two-parameter discrete distribution that shows a bathtub-shaped hazard function. Some statistical properties of the distribution are discussed. Three different methods are used to estimate its two unknown parameters. The point estimators of the parameters have no closed form. The bootstrap method is used to estimate the distributions of these point estimators. Different approximations of the interval estimations for the two-parameters are discussed. Real data sets are analyzed to show how this distribution works in practice. A simulation study is performed to investigate the properties of the estimations obtained and compare their performances.

• Journal of Nutrition and Health
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• v.32 no.5
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• pp.585-591
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• 1999

The purpose of the present study was to measure the dietary folate intake of Korean women of childbearing age. Folate intake obtained from 24-hour recall method and food frequency questionnaire was assessed in two hundred and ninety-three nonpregnant and non-lactating healthy women of childbearing age. The mean folate intake of women aged 20-29 was 112.8ug/day, 49.3% of their recommended level of 250ug/day. Folate intake of women aged 30-49 was 129.0ug/day, significantly higher than that of participants aged 20-29. A quartile analysis on the folate intake revealed that there significant differences in the consumption of dark green, leafy vegetables (p<0.01), other vegetables (p<0.01), and fruits and legumes(p<0.05) between the highest of childbearing age is far from adequate. To reach of the present study show that the folate intake of Korean women of childbearing age is far from adequate. To reach the recommended intake level of 250ug/day for women of childbearing age, folate supplementation and special nutrition education promoting folate intake might be necessary.

• 중국학논총
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• no.67
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• pp.157-177
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• 2020

The rapid change in the university environment due to the decrease in the school-age population calls for enhancing the competitiveness of China-related departments. In this paper, the university's competitiveness and dropout rate were studied in combination with various factors such as geographical location of Chinese-related departments set up at national universities, convergence with other departments, competition rate for entrance exams, scholarships, and employment rate that have a comprehensive impact on student satisfaction. In particular, the dropout rate presented research results that could help universities strengthen their competitiveness in China-related departments, such as by differentiating customized academic strategies according to the atmosphere of elimination through multiple regression analysis and quantile analysis. We hope this thesis will be the basis for policymaking and judgment in China-related departments.

• Annals of Occupational and Environmental Medicine
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• v.34
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• pp.41.1-41.10
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• 2022

Background: In Korea, few studies clarify insomnia and its association and absenteeism or presenteeism. Therefore, this study aims to examine the association between insomnia and absenteeism/presenteeism using the sixth Korean Working Conditions Survey. Methods: Insomnia was evaluated by the Minimal Insomnia Symptoms Scale (MISS). Absenteeism and presenteeism were assessed by asking if the employee had experienced absence or working despite being ill for the prior 12 months at the point of the survey. Multiple logistic analyses were conducted to explore insomnia and its association with absenteeism and presenteeism. Results: The odds ratios of insomnia for absenteeism and presenteeism were 3.48 (95% confidence interval [CI]: 2.76-4.39) and 3.68 (95% CI: 3.18-4.26) in the fully adjusted model. As the MISS scores increased, absenteeism and presenteeism showed the increasing trend that odd ratios increased accordingly from the first to the fourth quartile. Conclusions: This study observed that insomnia was related to both absenteeism and presenteeism among Korean employees.

• Korean Journal of Community Nutrition
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• v.10 no.5
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• pp.677-692
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• 2005

The assessment of sodium intake is complex because of the variety and nature of dietary sodium. This study intended to develop a dish frequency questionnaire (DFQ) for estimating the habitual sodium intake and a short DFQ for screening subjects with high or low sodium intake. For DFQ112, one hundred and twelve dish items were selected based on the information of sodium content of the one serving size and consumption frequency. Frequency of consumption was determined through nine categories ranging from more than 3 times a day to almost never to indicate how often the specified amount of each food item was consumed during the past 6 months. One hundred seventy one adults (male: 78, female: 93) who visited hypertension or health examination clinic participated in the validation study. DFQ55 was developed from DFQ112 by omitting the food items not frequently consumed, selecting the dish items that showed higher sodium content per one portion size and higher consumption frequency. To develop a short DFQs for classifying subjects with low or high sodium intakes, the weighed score according to the sodium content of one protion size was given to each dish item of DFQ25 or DFQ14 and multiplied with the consumption frequency score. A sum index of all the dish items was formed and called sodium index (Na index). For validation study the DFQ112, 2-day diet record and one 24-hour urine collection were analyzed to estimate sodium intakes. The sodium intakes estimated with DFQ112 and 24-h urine analysis showed $65\%$ agreement to be classified into the same quartile and showed significant correlation (r=0.563 p<0.05). However, the actual amount of sodium intake estimated with DFQ112 (male: 6221.9mg, female: 6127.6mg) showed substantial difference with that of 24-h urine analysis (male: 4556.9mg, female: 5107.4mg). The sodium intake estimated with DFQ55 (male: 4848.5mg, female: 4884.3mg) showed small difference from that estimated with 24-h urine analysis, higher proportion to be classfied into the same quartile and higher correlation with the sodium intakes estimated with 24-h urine analysis and systolic blood pressure. It seems DFQ55 can be used as a tool for quantitative estimation of sodium intake. Na index25 or Na index14 showed $39\~50\%$ agreement to be classified into the same quartile, substantial correlations with the sodium intake estimated with DFQ55 and significant correlations with the sodium intake estimated with 24-h urine analysis. When point 119 for Na index25 was used as a criterion of low sodium intake, sensitivity, specificity and positive predictive value was $62.5\%,\;81.8\%\;and\;53.2\%$, respectively. When point 102 for Na index14 was used as a criterion of high sodium intake, sensitivity, specificity and positive predictive value were $73.8\%,\;84.0\%,\;62.0\%$, respectively. It seems the short DFQs using Na index 14 or Na index25 are simple, easy and proper instruments to classify the low or high sodium intake group.

• Journal of Nutrition and Health
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• v.50 no.1
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• pp.98-110
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• 2017

Purpose: The purpose of this study was to evaluate the dietary potassium intake, Na/K intake molar ratio, consumption of 18 food groups, and foods contributing to potassium intake of Korean adults as well as the relationships among quartile of potassium intake level and blood pressure, blood biochemical index. Methods: This study was conducted using the Korea National Health and Nutrition Examination Survey, 2007~2010. The total number of subjects was 20,291. All analyses were conducted using a survey weighting to account for the complex survey design. Results: Overall average intakes of potassium were 2,934.7, 3,070.6, 3,078.1, and 3,232.0 mg/day, and they significantly increased by year in Korean adults. The average dietary potassium intake was close to adequate intake (AI), whereas that of women was considerably lower than the AI. The Na/K intake molar ratio in males (2.89~3.23) was higher than in females (2.62~2.95). The major food groups contributing to potassium intake were vegetables, cereals, and fruits/meats. The two major foods contributing to potassium intake were polished rice and cabbage kimchi. The rankings of food source were as follows; polished rice > cabbage kimchi > potato > oriental melon > sweet potato > seaweed > radish > apple > black soybean. In 50~64 year old females, systolic blood pressure (SBP) significantly decreased (p < 0.01) and HDL-cholesterol significantly increased (p < 0.05) as potassium intake increased. Triglyceride (TG) was significantly higher in the other quartile of potassium intake level than in the first quartile (p < 0.05). Conclusion: In conclusion, our study suggests the need for an appropriate set of dietary reference intakes according to caloric intake by sex and age groups and for development of eating patterns to increase potassium intake and decrease sodium intake.

• The Journal of the Korea Contents Association
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• v.16 no.8
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• pp.366-375
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• 2016

This study evaluates the degree of the inequality of medical care expenditure and private health insurance benefits and the relation with household income inequality in korea health care system. This study used the 2014 korea Health Panel survey, and study method is Gini coefficient. The main results are as follow. First, average household income in 1st income quartile is 6,290,000won and 10st income quartile is 101,930,000won. And Gini coefficient of Korea household income is 0.3756. In other words, family income inequality is quite serious. Second, the Gini coefficient of the public institution supported medical care expenditure, such as health insurance and public assistance, is 0.0761, and the Gini coefficient of the expenditure of transportation fee and medical materials etc that don't supported is 0878. The inequality in medical care expenditure in public health care system and without public support aren't serious all. Third, Gini coefficient in excluding household medical care expenditure from household income slightly increased. That is, the medical care expenditure of our country household is the factor of aggravating the inequality of household income. Fourth, Gini coefficient of private health insurance benefits is 0.0927. Therefore, the ineqality in private insurance benefits is low. In addition, the Gini coefficient of the sum of private insurance benefits and household income is 0.3672. it decrease from Gini coefficient(0.3756) of household's. Private health insurance perform the functions somewhat weaken household income inequality. However, it is very little improvement.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.34 no.1
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• pp.117-133
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• 2014

In this study, we analysed impacts of the recent increasing trend of exceedance rainfall thresholds for separation of data set and different research periods using Quantile Regression (QR) approach. And also we performed significant test for time series data using linear regression, Mann-Kendall test and Sen test over the Korean major 8-city. Spring and summer precipitation was tend to significant increase, fall and winter precipitation was tend to decrease, and heavy rainy days in last 30 years have increased from 3.1 to 15 percent average. In addition, according to the annual ranking of rainfall occurs Top $10^{th}$ percentile of precipitation for 3IQR (inter quartile range) of the increasing trend, most of the precipitation at the point of increasing trend was confirmed. Quantile 90% percentile of the average rainfall 43.5mm, the increasing trend 0.1412mm/yr, Quantile 99% percentile of the average rainfall 68.0mm, the increasing trend in the 0.1314mm/yr were analyzed. The results can be used to analyze the recent increasing trend for the annual maximum value series information and the threshold extreme hydrologic information. And also can be used as a basis data for hydraulic structures design on reflect recent changes in climate characteristics.

• Journal of Preventive Medicine and Public Health
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• v.41 no.2
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• pp.115-120
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• 2008

Objectives : The purpose of this study was to examine the relationship between serum ferritin and the metabolic syndrome (MS). Methods : We conducted a cross-sectional study of 1,444 adults over age 40 and under age 70 that lived in a rural area and participated in a survey conducted as part of the Korean Rural Genomic Cohort Study (KRGCS). The MS was defined as the presence of at least three of the followings : elevated blood pressure, low high density lipoprotein cholesterol, elevated serum triglycerides, elevated plasma glucose, or abdominal obesity. After adjustment for age, alcohol intake, menopausal status, body mass index (BMI), high sensitivity C-reactive protein (hs-CRP), and alanine aminotransferase (ALT), odds ratios (ORs) for the prevalence of the MS by sex were calculated for quartiles of serum ferritin using logistic regression analysis. Results : The MS was more common in those persons , with the highest levels of serum ferritin, compared to persons with the lowest levels, in men (37.1% vs. 22.4%, p=0.006) and women (58.8% vs. 34.8, p<0.001). In both sexes, the greater the number of MS components presents, the greater the serum ferritin levels. After adjustment for age, alcohol intake, and menopausal status, the OR for metabolic syndrome, comparing the fourth quartile of ferritin with the first quartile, was 2.21 (95% confidence interval; CI=1.26-3.87; p-trend=0.024) in men and 2.10 (95% CI=1.40-3.17; p-trend=0.001) in women. However, after further adjustment for BMI, hs-CRP, and ALT, the ORs were statistically attenuated in both sexes. Conclusions : Moderately elevated serum ferritin levels were not independently associated with the prevalence of the MS after adjusting for other risk factors. Further studies are needed to obtain evidence concerning the association between serum ferritin levels and the MS.