• Journal of the Korea Academia-Industrial cooperation Society
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• v.13 no.9
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• pp.4073-4081
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• 2012

This study was designed to estimate the prevalence of arthritis and to identify subgroups with high prevalence rates of arthritis. Study subjects were 18,406 Korean adults aged 19 and more from the 4th (2007-2009) Korea National Health and Nutrition Examination Surveys data. Annual self-reported prevalence and its rate ratios by demographic and behavioral factors were calculated using SAS 9.2 with survey procedure. The result was as follows. The crude prevalence of arthritis was 11.7% (osteoarthritis 10.2% and rheumatoid arthritis 1.7%). The prevalence was increased by age strata (2.4% in 19-44 aged, 16.4% in 45-64, 38.3% in 65 and more). After adjusting for age, we found the subgroups with high prevalence: older people, women, residents in non-apartment area, separated and divorced people, people with low education, people with several occupations (agricultural and fishery workers, elementary occupations, and unemployed), people with low household incomes, people with medical aid, and people with higher BMI. Those subgroups may be target populations in community health programs to control the disability from arthritis.

• Clinical and Experimental Pediatrics
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• v.54 no.12
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• pp.501-506
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• 2011

Purpose: A high level of air pollutants can increase the number of patients with allergy-related diseases such as asthma and allergic rhinitis (AR). To analyze the association between air pollution and allergic disease, we investigated 2 areas in Korea: Incheon, an industrial area, and Jeju, a non-industrialized area. Methods: Second grade students at elementary schools (11 schools in Incheon and 45 schools in Jeju) were examined in a cross-sectional study. A questionnaire was used and a skin prick test was performed. The levels of $NO_2$, $CO_2$, $O_3$, particulate matter (PM) $PM_{10/2.5}$, formaldehyde, tVOCs, and dust mites in the classrooms and grounds were determined. Results: The levels of outdoor CO, $PM_{10}$, and $PM_{2.5}$ were significantly higher in Incheon (P<0.01). The levels of indoor CO, $CO_2$, $PM_{10}$, $PM_{2.5}$ were significantly higher in Incheon (P<0.01). The prevalence rates of AR symptoms at any time, AR symptoms during the last 12 months, diagnosis of rhinitis at any time, and AR treatment during the last 12 months were significantly higher in Incheon (P<0.01). The prevalence rate of wheezing or whistling at any time, and wheezing during the last 12 months were significantly higher in Incheon (P<0.01). Conclusion: We found that the children living in Incheon, which was more polluted than Jeju, had a higher rate of AR and asthma symptoms compared to children in Jeju. To determine the effect of air pollution on the development of the AR and asthma, further studies are needed.

• Journal of the Korean Society for Advanced Composite Structures
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• v.3 no.1
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• pp.29-34
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• 2012

Even though the longitudinally stiffened laminated composite plates with closed section ribs should be an effective system for axially compressed members, the existing researches on the applications of closed-section ribs, especially for the laminated composite plates, are not sufficient. This study is aimed to examine the influence of the sectional stiffness of U-shaped ribs on the buckling modes and strengths of laminated composite plates. Applying the orthotropic plates with eight layers of the layup $[(0^{\circ})_4]_s$ and $[(0^{\circ}/90^{\circ})_2]_s$, 3-dimensional finite element models for the U-rib stiffened plates were setup by using ABAQUS and then a series of eigenvalue analyses were conducted. From the parametric studies, the minimum required ply thicknesses as well as the buckling strengths were presented for the analysis models. The buckling strengths were compared with the theoretical critical stress equation for simply supported plates based on the Classical laminated plate theory. This study will contribute to the future study for evaluating the minimum required stiffness and optimum design of U-rib stiffened plates.

• The Korean Journal of Community Living Science
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• v.20 no.1
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• pp.81-89
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• 2009

The purpose of this study was to analyze the patterns and interrelationships for meeting recommendations of physical activity, sedentary behavior, and dietary behavior in elementary school students. A cross-sectional design was used to assess 259 students ages 11 to 13 years. Physical activity (moderate to vigorous physical activity $\geqq$60min/day), sedentary behavior (viewing time for TV, computer, DVD, video, etc<3hr/day), and dietary behavior (servings of fruits and vegetables$\geqq$5times/day) were categorized into two levels: meeting recommendations or not meeting recommendations. Parents' health behaviors and home environmental variables were assessed with self-reported measures. Chi-squared tests and independent t-tests were conducted to compare anthropometric variables and the prevalence of students not meeting the recommendation for the three health behaviors. Comparison between males and females and logistic linear regression were used to determine the interrelationships of three health behaviors. 25.9% of students did not meet the physical activity recommendations. 15.4% did not meet sedentary behavior recommendations, and 41.7% did not meet dietary recommendation. Only 39.8% of students met all three recommendations, but 19.0% did not meet over two recommendations. Patterns that simultaneously did not meet two recommendations were: sedentary and dietary behavior in males (8.1%), and physical activity and dietary behavior in females (10.4%). Students who did not meet dietary recommendations were at greater risk of not meeting physical activity (OR 2.76; 95% CI 1.15 to 6.64), and sedentary behavior (OR 3.07; 95% CI 1.15 to 8.16) compared with students who did meet dietary recommendations. The findings of this study support not an independent behavior approach but a multiple behavior approach taking into account gender and interrelationships among the three behaviors.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.34 no.10
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• pp.1393-1401
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• 2010

In this experimental study, we have examined the correlation between a human carpal motion and a surface electromyogram. The carpal motion patterns have been identified and the main muscles involved in the carpal motion have been determined by investigating the anatomical structure of a carpal. The torque acting against the carpal motion has been applied by using a device for carpal rehabilitation training, and the surface electromyogram signal corresponding to the torque at the main muscles has been measured. The root-mean-square (RMS) magnitude of the surface electromyogram signal has been calculated and used to analyze the correlation between the surface electromyogram signal and carpal motion. The experimental results have proved that for carpal torque values below $0.1\;N{\cdot}m$, the RMS magnitude of the surface electromyogram signal is linearly proportional to the carpal torque magnitude and that the carpal torque magnitude is linearly proportional to the cross-sectional area of the carpal muscles. Further, the analysis of the contribution of each muscle to the carpal motion has shown that the contribution of the most dominant muscle is consistently 60%. These three results can be applied to develop more sophisticated devices or robots for carpal rehabilitation training.

• Pediatric Gastroenterology, Hepatology & Nutrition
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• v.23 no.5
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• pp.457-463
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• 2020

Purpose: To analyze risk factors and various nutrients associated with stunting among children aged 6-60 months. Methods: This is a case-control and cross-sectional study between 40 stunting cases and 40 controls. Data on possible risk factors associated with stunting were obtained through direct interviews and using a questionnaire. Examination of vitamin D, zinc, albumin, and ferritin levels was performed on both groups. Data were analyzed using IBM SPSS Statistics for Windows, Version 23.0 (IBM Co., Armonk, NY, USA) to determine risk factors for stunting and to assess the relationship between nutritional levels and stunting. Results: The incidence of stunting was highest in children aged 12-36 months. Children with low weight and very low weight for age comprised of 55% and 22.5%, respectively, of the study participants. The highest mother's educational level was junior high school (40%). History of low birth weight (LBW) was more commonly observed in the stunting group than that in the control group (25.0% and 7.5%, respectively; p=0.034, odds ratio, 0.310 [95% confidence interval, 0.122-0.789]). Approximately 7.5% of cases had premature birth. Exclusive breast feeding was found to be not correlated with stunting. The mean zinc level in the stunting group was 34.17 ng/mL, which was different from that in the control group (50.83 ng/mL) (p=0.023). Blood ferritin, vitamin D, albumin, and calcium levels were not strongly correlated with stunting. Conclusion: LBW is the main risk factor contributing to stunting and is strongly associated with low zinc level.

• Journal of Preventive Medicine and Public Health
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• v.39 no.3
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• pp.235-242
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• 2006

Objectives: We wanted to determine the distribution of the clustering of the metabolic risk factors and we wanted to evaluate the related factors in young schoolchildren. Methods: A cross-sectional study of metabolic syndrome was conducted in an elementary school in Seoul, Korea. We evaluated fasting glucose, triglyceride, HDL cholesterol, blood pressures and the body mass index, and we used parent-reported questionnaires to assess the potential risk factors in 261 children (136 boys, 125 girls). We defined the metabolic risk factors as obesity or at risk for obesity ($\geqq$ 85th percentile for age and gender), a systolic or diastolic blood pressure at $\geqq90th$ percentile for age and gender, fasting glucose at $\geqq110mg/dl$, triglyceride at $\geqq110mg/dl$ and HDL cholesterol at $\leqq40mg/dl$. Results: There were 15.7% of the subjects who showed clustering of two or more metabolic risk factors, 2.3% of the subjects who showed clustering for three or more risk factors, and 0.8% of the subjects who showed clustering for four or more risk factors. A multivariate analysis revealed that a father smoking more than 20 cigarettes per day, a mother with a body mass index of = $25kg/m^2$, and the child eating precooked or frozen food more than once per day were associated with clustering of two or more components, with the odds ratios of 3.61 (95% CI=1.24-10.48), 5.50 (95% CI=1.39-21.73) and 8.04 (95% CI=1.67-38.81), respectively. Conclusions: This study shows that clustering of the metabolic risk factors is present in young schoolchildren in Korea, with the clustering being associated with parental smoking and obesity as well as the child's eating behavior. These results suggest that evaluation of metabolic risk factors and intervention for lifestyle factors may be needed in both young Korean children and their parents.

• Journal of Preventive Medicine and Public Health
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• v.31 no.4 s.63
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• pp.828-843
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• 1998

To find the association of perception of health status with lifestyle of different ethnic groups living in north-eastern part of China, a cross-sectional questionnaire survey was done by 10 local health workers for 375 Korean immigrants and 217 Chinese whose age was 30 years old or more. Because Korean immigrants showed higher mortality than Chinese, we expected to find significant lifestyle related with perception of health status which was known to be a predictor of mortality by different ethnic groups. The results were as follows : 1. We found that 59.7% of Yanbian Koreans and 42.9% of Yanbian Chinese felt unhealthy (p=0.000). 2. For Yanbian Koreans, significant variables associated with perception of health status were selected through logistic regression analysis and they were sex; female to male with an OR=2.45 (95% confidence interval[CI] 1.06, 5.64), prevalence of chronic illness with an OR=5.48 (95% CI: 4.62, 15.56), mont of meal; small or moderate to full with an OR=2.67 (95% CI : 1.40, 5.09), preference of spicy food with an OR=1.78 (95% CI : 1.04, 3.04), and less amount intake of vitamin $B_2$, with an OR=2.29 (95% CI : 1.33, 3.93). 3. For Yanbian Chinese, significant variables associated with perception of health status were prevalence of chronic illness with an OR=4.97 (95% CI : 2.11, 11.68), history of taking ginseng with an OR=3.72 (95% CI : 1.33, 10.43), and less intake of vitamin C with an OR=0.18 (95% CI : 0.07, 0.46). In conclusion, sex, presence of chronic illness, dietary habit, and amount of $vitamin-B_1$ intake were associated with perception of health status in Yanbian Koreans. Presence of chronic illness, experience of ginseng intake, and amount of vitamin C intake were associated with perception of health status in Yanbian Chinese. To prove cause-effect relation between perception of health status and lifestyle, further study is needed for these different ethnic groups.

• Journal of Preventive Medicine and Public Health
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• v.31 no.1 s.60
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• pp.59-71
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• 1998

To examine the association of hypertension with cluster of obesity, abnormal glucose and dyslipidemia in Korean urban population, we conducted this cross-sectional study among 3027 men and 2127 women age 20-85 years who visited a prevention center between May 1991 and June 1995 for a multiphasic health check at St. Mary's Hospital, Seoul. By the self-administered questionnaire, the informations of educational attainments, monthly income, alcohol consumption, cigarette smoking, and physical excercise level were obtained. Height, weight, and blood pressure were measured by a trained nurse. The fasting blood sugar (FBS), total cholesterol, high density lipoprotein (HDL) cholesterol and triglyceride were tested by enzyme method. Low density lipoprotein (LDL) cholesterol was calculated by 'total cholesterol - HDL cholesterol - triglyceride/5'. For testing the differences of cardiovascular risk factors between hypertension and normotension group, 1-test and $\chi^2$-test were performed. For the age adjusted odds ratios of hypertension in persons with obesity, abnormal glucose, and dyslipidemia compared with normal, logistic regression was performed by using SAS pakageprograme. The results obtained were as follows: 1. Age, weight, body mass index(BMI), blood glucose, total cholesterol, LDL cholesterol, and triglyceride of hypertension group in men and women were significantly higher than normotension group, but height and HDL cholesterol of hypertension group only in women significantly lower than normotension group. The frequency of obesity $(BMI\geq25kg/m^2)$, abnormal glucose $(\geq\;120mg/dl)$, hypercholesterolemia $(\geq\;240mg/dl)$, lower HDL cholesterol (<45 mg/dl in women only), higher LDL cholesterol $(\geq\;160mg/dl)$, and hyper hypertriglyceridemia $(\geq\;250mg/dl)$ in hypertension group of men and women were significantly higher than normotension group. 2. Systolic and diastolic blood pressure were negatively correlated with hight, but positively with age, weight, BMI, total cholesterol, LDL cholesterol, and triglyceride in men and women. BMI was positively correlated with fasting blood sugar, total cholesterol, LDL cholesterol and triglyceride but negatively with HDL cholesterol. 3. The age adjusted odds ratios of hypertension were as follows in men and women : among persons who were obese compared with those nonobese, 2.53 (95% Confidence Intervals [C.I.] 2.08-3.07) and 2.22 (95%C.I. 1.71-2.87): among persons who were abnormal glucose compared with those normoglycemic, 1.43 (95%C.I 1.13-1.82) and 2.01 (95%C.I 1.36-2.94): and among persons who were dyslipidemia (hypercholesterolemia or lower HDL cholesterol or higher LDL cholesterol or hypertriglyceridemia) compared with those normal lipid, 1.59 (95%C.I 1.30-1.95) and 1.51 (95%C.I 1.16-1.96). After combined more than one risk factor, the odds ratios were increased. Among persons with cluster of obesity, abnormal glucose, and dyslipidemia, the odds ratio of hypertension was 2.25 (95%C.I 1.47-3.37) in men and 3.02 (95%C.I 1.71-5.30) in women. In conclusion, it was suggested that hypertension was associated with cluster of obesity, abnormal glucose, dyslipidemia in this Korean urban population.

• Journal of Preventive Medicine and Public Health
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• v.32 no.2
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• pp.228-235
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• 1999

Objectives: Despite the importance of human immunodeficiency virus(HIV) transmission through heterosexual contact, the features of heterosexual transmission has not been well studied in Korea. So we conducted a cross sectional study to determine the transmission rates in married couples and assess risk factors for male to female heterosexual transmission of HIV. Methods: 169 HIV-infected males and their female sex partners were recruited from 1985 to tune 1998. We examined female sex partner's HIV infection status and interviewed male index partners and their female sex partners about demographic characteristics and sexual practices. We analysed heterosexual transmission rate by epidemiologic characteristics, disease status and sexual practices. And we assessed risk factors for HIV infection by univariate and multivariate analysis. Results: 30 female sex partners were infected at enrollment, yielding an transmission rate of 17.8%. Among couples who had used condoms consistently, none of the female sex partners was infected with HIV. In univariate analysis the significant risk factors were full blown AIDS status (OR=4.1, 95% CI: 1.49-11.43) and low CD4 T cell count of index partners at enrollment (OR=7.8, 95% CI: 2.19-27.80). In multivariate analysis HIV-1 RNA levels was significant risk factor when adjusted by CD4 T cell courts and mean sexual contacts per month (OR=19.2, 95% CI: 1.03-357.59) Conclusion: The risk of male to female heterosexual transmission increased with advanced stages of HIV infection in the index male partners.