• Journal of Preventive Medicine and Public Health
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• v.36 no.2
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• pp.137-146
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• 2003

Objectives : Impaired hearing is a prevalent occupational hazard, not only in industry, but also in the armed forces. In military life, noise has unusual characteristics, and constitutes a serious hazard to hearing. The aim of this study was to analyze the hearing threshold data in order to compare the hearing loss among shipyard workers, representing different workers, and a military service background. Methods : A cross-sectional audiological survey, combined with a questionnaire study, was conducted on a stratified random sample of 440 shipyard workers, with long-term exposure to noise. The employees were divided into four groups, according to their working and military service backgrounds, in relation to their exposure to noise. Results : As expected, the working and military noise exposure group (Group I) had significantly poorer hearing than the other groups. The high frequencies (2-8 kHz) showed the greatest difference in terms of poorer fearing in both ears. The prevalence of noise-induced hearing loss (NIHL) was highest in Group I. A logistic regression analysis was applied to determine the dependence of the NIHL in relation to age, smoking, drinking, working duration, ear protection, past history of ear diseases, and working and military sonics backgrounds, on the noise exposure The important factors found to be related to the NIHL, in relation to noise exposure were: age, work duration, and working and military service backgrounds. The adjusted odds ratio estimates for NIML in the right ear were 4.5 times greater (95% CI 1.7-11.6) for the military noise exposed group, and 7.9 times greater (95% CI 2.0-31.3) for the working noise exposed group than in the controls. The hearing thresholds at the pure-tone average and 4 kHz were significantly increased with age and work duration with both the working and military service backgrounds. Conclusions : From these results, specific preventive programs were planned, which should be assessed by epidemiological surveillance of the military noise exposed population.

• Journal of Nutrition and Health
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• v.41 no.8
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• pp.839-850
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• 2008

This study describes the demographic and diet-related psychosocial correlates of nutrition label use, and examines the relationship between label use and diet. Self-reported dada from a population-based cross-sectional survey of 2073 Korean women aged 20 to 60 years were collected to identify demographic and health-related characteristics, belief on diet-disease relationship, awareness on importance of healthy eating practice and diet quality associated with label use. Label users, who are in the stage of action and maintenance (31.6%), were more likely to have belief on nutrient-disease relationship (in sodium, cholesterol, sugar and trans fat) and were more likely to have higher awareness of the importance of healthy eating practice compared with label nonusers, who are in the stage of precontemplation, contemplation and preparation. Label users were more likely to have higher dietary quality compared with label nonusers [odds ratio (OR) = 2.01; 95% confidence interval (CI): 1.66, 2.44](P < 0.001). Also, label use appeared to be associated with the consumption of diets that were higher vegetables and fruits, and lower in cholesterol. The findings of this study suggests that reading nutrition labels on food packages may improve food choices and enable healthful dietary practices.

• Restorative Dentistry and Endodontics
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• v.32 no.6
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• pp.530-541
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• 2007

Currently, various Nickel-Titanium rotary files are used in endodontic treatment, but there is no one perfect system that can be applied to any clinical situation. Therefore, the combined uses of various file systems which can emphasize the advantages of each system are introduced as hybrid instrumentation. The ProTaper system is efficient in body shaping and apical pre-enlargement but is reported to have more possibility of transportation and produce more aberrations and deformation in more or less severe curved canals. Recently, new ProTaper system(ProTaper Universal) with different configuration and cross-sectional design to overcome the week points of ProTaper have been marketed. The purpose of this study was to compare and evaluate the shaping abilities of ProTaper, ProTaper Universal system, and two hybrid methods using S-series of ProTaper Universal and Hero Shaper or ProFile. The time lapses for instrumentation were measured and the used files were inspected for distortion. The pre- and post-instrumented root canals were scanned and superimposed to evaluate the aberrations and reduction of root canal curvature and change of radius of canal curvature. The increased canal width and apical centering ratio were calculated at 1, 2, 3, 4 and 5 mm levels from apical foramen. Under the conditions of this study, the ProTaper Universal seems to have better shaping ability than ProTaper in terms of instrumented width and instrumentation time. It may be suggested that the ProTaper Universal system is efficient as much as hybrid instrumentation using ProTaper and other constant-tapered NiTi file systems in highly experienced operators.

• Journal of Korean Society of Forest Science
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• v.85 no.2
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• pp.288-299
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• 1996

This is the basic study to investigate the amount of transpirational water loss in thrifty mature Quercus mongolica stand by the heat pulse method. The differences of heat pulse velocity by direction and depth, differences of heat pulse velocity by dominant, codominant and suppressed trees, diurnal changes of heat pulse velocity due to the change of leaf water potential, vapor pressure deficit and radiation, and sap flow path way in sapwood by dye penetration were measured in stems. Finally the amounts of daily and annual transpiration in stand were calculated by the heat pulse velocity. The results obtained were summarized as follows : 1. Relationship between heat pulse velocity(V) and sap flow rate(SFR) was obtained as a equation of SFR=1.37V. 2. The sap flow rate was high in the order of dominant, codominant, and suppressed trees. The daily heat pulse velocity changed with radiation, temperature and vapor pressure deficit. 3. The heat pulse velocity showed the similar diurnal variation as the leaf water potential change. 4. The heat pulse velocity showed the highest value in May(4.0cm/hr in average), the lowest one in July(2.9cm/hr in average). 5. The heat pulse velocity in the same stem presented the highest value in the northern direction, medium in western, and the lowest in southern and eastern. 6. The heat pulse velocity in stem was highest in 0.5cm, medium in 1.0cm, and lowest in 1.5cm depth from the surface of stem. 7. The sap flow path way in stem showed sectorial straight ascent pattern in four sample trees. 8. The amount of sap flow(SF) was presented as a equation of $SF=1.37A{\cdot}V$(A: the cross-sectional area of sapwood, V: heat pulse velocity), and especially SF was larger in dominant tree than codominant and suppressed trees. 9. The amount of daily transpiration was 5.6ton/ha/day, and its composition ratio was 72% at day and 28% at night. 10. The amount of stand transpiration per month was largest in May(168ton/ha/month), lowest in July(125ton/ha/month). The amount of stand transpiration per year was 839ton/ha/year.

• Journal of agricultural medicine and community health
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• v.40 no.3
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• pp.126-136
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• 2015

Objectives: This study was performed to investigate the effects of a health education program for the aged on knowledge about the warning signs and symptoms of acute myocardial infarction and stroke. Methods: Data from 337 elderly people (159 participated and 178 non-participated) at senior centers in Jeju-si were collected by 1 to 1 interview from January to March 2012, one year after the education program provided. Two stages of study were performed: Cross-sectional, case-control study on the level of knowledge about the warning signs and symptoms; and multivariate logistic regression to fine out predictors of optimal awareness. Results: No significant discrepancy of knowledge level between case and control group was found. The knowledge level as high as a surge was shown in both groups one year later. A surge of knowledge had been shown after the education provided in one month. The factors affecting the optimal level of knowledge were education (Odds ratio 3.01; Confidence Interval 1.72-5.26; P-value <0.001) and 7 days of watching TV news per week (2.97; 1.68-5.23; P<0.001). However, participation in the health education was not significant (1.60; 0.98-2.61; P=0.059). Conclusions: The effects of a targeted program in high-risk groups for cardio-cerebrovascular disease are only guaranteed in the enhancement by a population-based mass-media education campaign.

• Sleep Medicine and Psychophysiology
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• v.5 no.1
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• pp.88-102
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• 1998

Objectives : We attempted to study obstructive sleep apnea symptoms prevalence and sleep apnea-associated factors in Korean rural adult population. Methods : In 1,441 adult subjects of three rural communities selected by cluster sampling, we administered an epidemiologic survey using questionnaire methods from July 14, 1996 to July 28, 1996. Results : 1) In 14.1% of the subjects, snoring was reported to occur almost daily and 2.9% of the subjects reported sleep apnea symptoms occurring almost daily. 2) Snoring and sleep apnea symptoms were found more frequently in males or in mid-aged group(45 - 64 years old) than in females or in younger- and older-aged groups, respectively. Compared with the subjects who have no snoring, the subjects who have snoring or sleep apnea symptoms had greater body mass index(BMI), waist-hip ratio, hemoglobin level, RBC count, and higher diastolic blood pressure. 3) Cigarette smoking and alcohol drinking more than once a week were significantly associated with suffering from sleep apnea symptoms. 4) In multiple logistic regression analysis, being male, mid-aged, and greater BMI were independently associated with the presence of snoring and sleep apnea symptoms. Conclusion : We conclude that, in the Korean rural adult population, males or mid-aged group suffers more from snoring and sleep apnea symptoms than females or younger- and older-aged groups. In addition, being male, mid-aged, and greater BMI were significantly associated independently with the presence of snoring and sleep apnea symptoms.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.6
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• pp.135-146
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• 2011

Steel structures have been generally painted to prevent corrosion damage. However, the painted film is deteriorated with increase in service life, and then corrosion damage resulting in cross sectional area occurs on steel surface. As a result, the buckling strength of steel structures can be decreased due to the corrosion damages. The evaluation method of the axial buckling strength of columns about a variety of section shapes and supporting conditions have been presented, but evaluation method of buckling strength about irregular nonprismatic columns is not established. In this study, the axial buckling strength of corroded steels was evaluated based on the buckling test results of corroded steel specimens that were cut off at a temporary steel structure. The corroded specimens were picked up total 10 specimens according to various slenderness ratio from the web of a temporary structure's main beam. The length of specimens is 200, 300, 400, 500 and 600mm respectively. The rust productions were removed by the chemical treatment. Then, the surface geometry was measured at intervals of $1{\times}1mm$ by using the optical 3D digitizing system, and the residual thickness of the specimens was calculated. The axial buckling test was performed on 10 corroded specimens and 12 non-corroded specimens under the fixed-fixed support condition. From the test results, the effect of corrosion damages on axial buckling load was investigated. Regardless of corrosion damage degree, the axial buckling strength of corroded specimens and non-corroded specimens was evaluated identically by using minimum average residual thickness or average residual thickness to minus its standard deviation. Reasonable measuring intervals of residual thickness was proposed by using the results to apply for practical works.

• Journal of Preventive Medicine and Public Health
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• v.42 no.6
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• pp.386-391
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• 2009

Objectives : This cross-sectional study was performed to examine if the serum gamma-glutamyltransferase (GGT) level that is within its normal range is associated with the risk of type 2 diabetes and if the association between the waist hip ratio (WHR) and type 2 diabetes is different depending on the serum GGT levels. Methods : The study subjects were 23,436 persons aged 40 years or older and who participated in regular health check-ups at 11 hospitals (males: 5,821, females: 17,615). The gender-specific quintiles of the serum GGT and WHR were used to examine the associations with type 2 diabetes. Results : The serum GGT levels within their normal range were positively associated with type 2 diabetes only in women. The adjusted odds ratios (ORs) were 1.0, 1.0, 1.4, 2.1, and 2.5 according to the quintiles of the serum GGT ($p_{trend}$<0.01). The WHR was more strongly associated with the prevalence of diabetes among the women with a high-normal serum GGT level as compared with those with a low-normal serum GGT level (p for interaction=0.02). For example, the adjusted ORs for women with a low normal serum GGT level were 1.0, 1.2, 1.5, 2.2, and 2.4 according to the quintiles of the WHR, while those figures were 1.0, 2.4, 3.6, 5.0, and 8.3 among the women with a high normal serum GGT level. However, in men, the serum GGT was very weakly associated with type 2 diabetes and the association between the WHR and type 2 diabetes was not different depending on the serum GGT level. Conclusions : Serum GGT within its normal range was positively associated with type 2 diabetes, and central obesity was more strongly associated with the prevalence of type 2 diabetes when the serum GGT level was highnormal. However, these associations were observed only in women, which is different from the previous findings. The stronger relation between central obesity and type 2 diabetes among women with a high-normal serum GGT level can be useful for selecting a group that is at high risk for type 2 diabetes irregardless of whatever the underlying mechanism is.

• Korean journal of health promotion
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• v.18 no.4
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• pp.177-183
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• 2018

Background: Many studies have reported that adolescents living with single parent have a high risk of obesity. However, those studies did not explore the implication of the gender of single parent living with adolescents. This study investigated the differences in obesity rates according to status of co-residence with their parents in Korean adolescents. The family living with single parent was classified into the family living with single father and the family living with single mother. Methods: This cross-sectional study involved 59,602 adolescents who participated in the 2017 Korea Youth Risk Behavior Web-based Survey. The data on height, weight, status of co-residence with parents, and the other variables were obtained through online questionnaires. Results: In male adolescents, the family living with single mother was related to a high proportion of obesity (odds ratio [OR] 1.24, 95% confidence interval [CI] 1.09-1.40) and overweight (OR 1.17, 95% CI 1.03-1.34). However, in female adolescents, the family living with single father was related to a high proportion of obesity (OR 1.49, 95% CI 1.23-1.82). In addition, female adolescents living with neither parent were more likely to be obese (OR 1.47, 95% CI 1.13-1.91) and overweight (OR 1.31, 95% CI 1.00-1.70). Conclusions: This study showed a risk of obesity in adolescents living with single parent differs according to the gender of single parent living with adolescents. Not adolescents living with a same-gender parent, but those living with an opposite-gender parent have a high risk of obesity.

• Korean journal of health promotion
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• v.17 no.2
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• pp.109-118
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• 2017

Background: Abdominal obesity as measured by waist-to-height ratio (WHtR) may have stronger and inverse associations with cardiovascular (CV) health than overall obesity as measured by body mass index (BMI). However, there was some challenges for controversies. We aimed to examine the associations of WHtR and BMI with CV health among Korean children using data of the 2010-2012 Korea National Health and Nutrition Examination Survey. Methods: A cross-sectional study was conducted with the sample of 2,363 children by analyzing by gender and two-age groups (10-12 and 13-18 years). Overall obesity was categorized into 3 groups by BMI percentile: non-overweight (<85), overweight (${\geq}85$), and obesity groups (${\geq}95$). Abdominal obesity was categorized into 2 groups by WHtR: normal (<0.5) and abdominal obesity groups (${\geq}0.5$). The CV health score was defined as a z-score by calculating the sum of 7 CV factors. Results: The overweight/obesity groups had significantly lower CV health scores than the normal group (P<0.05) in boys and girls aged either 10-12 years or 13-18 years after adjusting for covariates. The abdominal obesity group also showed significantly lower CV health scores than the normal group (P<0.05) in all the groups; this significant association remained significant in boys aged 13-18 years even after further adjusting for BMI category (P<0.01). Conclusions: Among boys aged 13-18 years, abdominal obesity as measured by WHtR was significantly and inversely associated with CV health, independent of BMI category. Therefore, it should be considered to assess the level of abdominal obesity as a measure of CV health in late adolescent boys.