• KIEAE Journal
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• v.5 no.1
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• pp.51-57
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• 2005

In this study, time-dependent concentration variations of VOCs from fixed furniture and Ondol floor widely used as finishing material of the floor were measured, and prediction equations were developed based on the measured results. VOCs were measured and analyzed based on EPA TO-17 and NIOSH 1500, 1501 method respectively, and GC/FID were used for the analysis of VOCs concentration. Measurements were carried out for 10 days after the installation of furniture and for 40 days after the installation of the floor in the residence constructed more than 10 years ago. In both case of floor and furniture installation, time-dependent concentration decay of VOCs can be properly converted into logarithmic scale. Especially in case of furniture, toluene showed the highest concentration and took longest time to decay. As a result of the prediction of VOCs concentration decay under different air change rate using estimated equations, concentration decay rate of indoor VOCs increased rapidly as the air change rate also increased.

• Journal of Home Health Care Nursing
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• v.25 no.2
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• pp.197-208
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• 2018

Purpose: This study investigated the smartphone using time, troubles with smartphone usage, and related factors in Korean adolescent smartphone users. Methods: Data were obtained from 54,603 subjects aged 13 to 18 years in the 2017 13th Korea Youth Risk Behavior Web-based Survey Results: The study analyzed the school type, academic achievement, residence type, weekly average allowance, and usual counselor, perceived stress, happiness, and depression of the subjects showed a significant difference in the variable of troubles experienced by the smartphone user. Multiple sample logistic regression analysis showed that adolescents with low academic achievement (weekday, weekend OR = 1.78, 1.65), low economic status (weekday, weekend OR = 1.17, 1.37), friends with distress counselors (weekday, weekend OR = 1.29, 1.24), weekly average allowance (weekday, weekend OR = 1.85, 1.50), stressed (weekend OR = 1.25), depressed (weekday, weekend OR = 1.26, 1.14), family troubles (weekday, weekend OR = 1.14, 1.15), friendship troubles (weekday, weekend OR = 1.70, 1.38), and academic performance troubles (weekday, weekend OR = 1.28, 1.38) spent more than the average using time on their smartphones. Conclusion: To prevent overdependence on smartphone use among adolescents, a nursing intervention program that relieves stress and lowers depression should be developed.

• Journal of Community Nutrition
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• v.8 no.1
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• pp.31-37
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• 2006

This study is to compare the prevalence of obesity between Korean-American children and Korean children, and to investigate the role of environmental factors in obesity development. Prevalence of child obesity is compared by their residence, parents' anthropometric data, education and occupation, and the length of immigration, and birth place of the children. A total of 593 children between the ages of 9 and 12 were examined. 262 Korean-American children (KcUS group) from New Jersey, USA and 331 Korean children (KcK group) from Seoul, Korea were compared. KcUS group showed a higher obesity rate (male: 12.6% and female: 8.2%), compared to KcK group (male: 8.0% and female: 5.1 %). KcK male children showed lower weight and prevalence of obesity than Korean-American male children who lived in the United States for more than three years. Korean-American female children had higher weight and obesity rate than Korean female children. Waist circumference and hip circumference were also higher in obese children in both KcK and KcUS groups. The children who live in America had an odds ratio of 1.69 to be obese compared to KcK, while those born in America and those who have lived in America for more than 3 years had odds ratios of 1.53 and 1.25 to be obese, respectively. This study found that environmental factors, immigration to America for instance, could playa bigger role in child obese development than the genetic factor.

• Journal of Korean Society for Atmospheric Environment
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• v.19 no.2
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• pp.179-189
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• 2003

The concentration of gaseous elemental mercury (Hg) was measured concurrently with relevant environmental parameters from Yang-Jae monitoring station in Seoul during Sept. 1997 to June 2002. Although data collection was disrupted for certain periods, the grand mean concentration of Hg for this five year period was found at 5.32 $\pm$ 3.53 ng m$^{-3}$ (N = 27,170). Because of short resolution of data acquisition, we were able to examine the temporal variability of Hg at varying time scale. The diurnal variability of Hg, when investigated for each of those five years, indicated consistently the dominance of nighttime over daytime. If examined at seasonal scale, Hg level was systematically higher during winter/spring than summer/fall period. The results of this short-term variability were best explained by the combined effects of such factors as meteorological conditions (formation of inversion layer and seasonal changes) and anthropogenic source processes. However, examination of long-term variation Pattern was much more complicated to explain. Thus, extension of our study is needed to diagnose the future direction in long-term trend of Hg behavior.

• Korean Journal of Community Nutrition
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• v.26 no.1
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• pp.37-47
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• 2021

Objectives: The purpose of this study was to discover the changes in obesity prevalence and dietary habits in Korean adults residing in various residential areas during the last 10 years. Methods: Data on Korean adults aged 19 years and above was obtained from the 4th (2007-2009) and the 7th (2016-2018) Korea National Health and Nutrition Examination Survey. The subjects were classified into metropolitan (4th: n=5,977, 7th: n=6,651), urban (4th: n=4,511, 7th: n=5,512) and rural (4th: n=3,566, 7th: n=2,570) based on their residence. The general characteristics, nutrient intake, intake amount, food groups, and healthy dietary factors were analyzed. The association between residential areas and obesity prevalence were analyzed by multiple logistic regression. Results: In urban and rural areas, the obesity rate increased in the 7th survey compared to the 4th survey, excluding the metropolitan area. The carbohydrate intake decreased, and lipid intake increased in the 7th survey compared to the 4th survey. Over the same period, the intake of cereals and vegetables decreased, and the intake of meat and processed foods increased. Rural residents had a higher intake of cereals and vegetables, and a lower intake of milk and processed foods than those in metropolitan areas and urban residents. The proportion of subjects who practiced a healthy diet increased in the 7th survey compared to the 4th survey. In the 4th survey, there was no relationship seen between the prevalence of obesity and the subject's residential area, but in the 7th survey, the odds ratio of obesity was higher in rural areas than in the metropolitan areas, confirming the regional gap (OR: 1.16, 95% CI=1.00-1.36, P=0.044). Conclusions: This study showed that the obesity prevalence increased in rural residents compared to metropolitan residents, indicating a gap between the regions. The nutrient intake and intake of food groups changed in the 10 years under consideration, and there were differences seen between regions. Therefore, it is necessary to formulate a policy that will reduce obesity prevalence and health inequalities between regions.

• Korean Journal of Community Nutrition
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• v.14 no.1
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• pp.22-30
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• 2009

This study aimed to examine nutritional status and similarities of diets between Vietnamese female immigrants and Korean spouses and dietary changes of Vietnamese females after immigration. Subjects were 608 couples visiting 13 medical centers for the Cohort of Intermarried Women in Korea from November 2006 to November 2007. Anthropometric and biochemical measurements were obtained and dietary intakes were assessed using one-day 24-hour recall. Sixty-eight percent of wives answered there have been changes in their diets and consumptions of meats, fish, dairy products, vegetables, and fruits increased after immigration. Energy intakes of wives and spouses were 1491.7 kcal and 1788.8 kcal, respectively, showing most couples (80.1%) consumed less than the Korean estimated energy requirements. More than half of the couples were below the Korean estimated average requirements of zinc, vitamin $B_2$, and folate. The correlation coefficients between couples ranged 0.15-0.38 for unadjusted, 0.22-0.35 for per 1000 kcal, and 0.21-0.40 for energy-adjusted, respectively. The proportions of couples in the same quartiles of each nutrient intake and in the same answers of each question of Mini Dietary Assessment were about 30% across nutrients and around 50% across questions. The length of residence is related to similarities of nutrient intakes between couples: similarities decreased after 3 years of residence in Korea. In conclusion, nutritional intakes of inter-married couples were inadequate although wives reported that their dietary intakes increased after immigration. Inadequate nutrient intakes of wives were partly explained by similar diets between couples because these wives without enough adjustment to Korean culture were more likely to follow what their spouses ate. Findings from this study may be helpful to improve the nutritional status of inter-married couples and make policies and programs for them. A follow-up study should identify factors affecting inadequate nutritional status of intermarried couples and similarities of their diets.

• Journal of the Korean Society of Marine Environment & Safety
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• v.27 no.1
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• pp.153-160
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• 2021

Nitrous oxide is a global warming substance and is known as the main cause of the destruction of the ozone layer because its global warming effect is 310 times stronger than carbon dioxide, and it takes 120 years to decompose. Therefore, in this study, we investigated the characteristics of NOx emission from N2O reduction by thermal decomposition of N2O. Bunsen premixed flames were adopted as a heat source to form a high-temperature flow field, and the experimental variables were nozzle exit velocity, co-axial velocity, and N2O dilution rate. NO production rates increased with increasing N2O dilution rates, regardless of nozzle exit velocities and co-axial flow rates. For N2O, large quantities were emitted from a stable premixed flame with suppressed combustion instability (Kelvin Helmholtz instability) because the thermal decomposition time is not sufficient with the relatively short residence time of N2O near the flame surface. Thus, to improve the reduction efficiency of N2O, it is considered effective to increase the residence time of N2O by selecting the nozzle exit velocities, where K-H instability is generated and formed a flow structure of toroidal vortex near the flame surface.

• Korean Journal of Community Nutrition
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• v.26 no.6
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• pp.467-481
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• 2021

Objectives: The purpose of this study was to examine the biochemical characteristics, intake of energy, and nutrients by household income levels of Korean adolescents aged 12 to 18 years. Methods: Data from the 6th (2013 ~ 2015) Korea National Health and Nutrition Examination Survey (KNHNES) were used for the study. A total of 1,839 (966 boys, 873 girls) subjects were included, and they were divided into four income groups according to their household income level. We examined general characteristics (gender, region of residence, skipping or not-skipping breakfast, lunch, dinner, frequency of eating-out), anthropometric characteristics (height, weight, weight status), biochemical characteristics (fasting plasma glucose, blood urea nitrogen, creatinine, triglycerides, cholesterol, HDL-cholesterol, hemoglobin, and hematocrit), the quantitative intake of energy and nutrients using the Korean Dietary Reference Intakes (KDRI), and the qualitative intake evaluated by the nutrition adequacy ratio (NAR) and mean nutrition adequacy ratio (MAR) of the four groups. Results: There were significant differences by income group within the region of residence and the rate of skipping breakfast, lunch, and dinner. The low-income group had a higher rate of skipping breakfast, lunch, and dinner. According to the income group, there was a difference in the height of boys, and there was no difference in the weight and obesity of boys and girls. In the biochemical characteristics, only the hematocrit of girls showed differences by income group. The quantitative intake of energy and nutrients compared with KDRI differed by income group. There were differences in energy, carbohydrates, proteins, thiamin, riboflavin, niacin, and phosphorus levels in boys and protein, vitamin A, niacin, and sodium levels in girls. The qualitative intake of energy and nutrients examined using NAR and MAR also differed according to the income group. The NAR showed differences in calcium in boys and vitamin C and calcium in girls. The MAR revealed differences in both boys and girls by income group. Conclusions: Among adolescents in the low-income group, the rate of skipping meals was high, and the quantitative and qualitative intake of energy and some nutrients was low. It is suggested that the nutritional intake can be improved by lowering the rate of skipping breakfast, lunch, dinner. We suggest that even just providing breakfast in schools can be considered highly effective in improving the rate of avoidance of skipping meals and improving nutrient intake. Also, we suggest that it is necessary to improve the food environment, food availability, and food accessibility through national and social support for low-household income adolescents.

• The Journal of Korea Institute of Information, Electronics, and Communication Technology
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• v.16 no.1
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• pp.50-59
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• 2023

The purpose of this study was to analyze the patients hospitalized with damage by injury code based on data for two years in 2020 and 2021 of A institution located in Gangneung, Gangwon-do. Analyzed the injury codes with a large number of occurrences per year, and analyzed the injury codes of external causes accordingly. The cause of the injury code was analyzed by analyzing the frequency of the injury code of external causes. Injury code S0650 had the highest frequency of injury code of external causes W189 and X5999, which was judged to be the cause of traumatic subdural hemorrhage without open intracranial wounds when falling in an unspecified place or toilet. Injury code S72120 had the highest frequency of injury code of external causes W010 and W180, and it was judged to be the cause of obstructive femoral intertrochanteric fracture that occurs when falling in the residence. The injury code S32090 had a high frequency of X5999, and it was analyzed that it caused the obstructive fracture of the lumbar region due to an accident caused by exposure in an unspecified place, and the injury code S72.090 had a high frequency of W010 and W180. It was confirmed that the cause of the obstructive fracture of the femoral neck was mainly caused by slipping or slipping in the residence, and the injury code S0220 had a high frequency of the injury code of external causes Y049, and it was confirmed that the fibula was fractured mainly by the force or fist. As such, the cause of the injury code was analyzed by analyzing the frequency of the injury code for each injury code of external causes.

• Journal of Preventive Medicine and Public Health
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• v.40 no.6
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• pp.461-466
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• 2007

Objectives : The purpose of this study was to examine the determinants of sterilization in South Korea. Methods : This study was based on the data from the Korea National Fertility Survey carried out in the year 2000 by the Korea Institute of Health and Social Affairs. The subjects of the analysis were 4,604 women and their husbands who were in their first marriage, in the age group of 15-49 years. The data were analyzed by multiple logistic regression analysis. Results : Consistent with the findings of previous studies, the woman#s age and the number of total children increased the likelihood of sterilization. In addition, the year of marriage had a strong positive association with sterilization. Interestingly, the number of surviving sons tended to increase the likelihood of sterilization, whereas the woman#s education level and age at the time of marriage showed a negative association with sterilization. Religion, place of residence, son preference, and the husband#s education level, age and type of occupation were not significant determinants of sterilization. Conclusions : The sex of previous children and lower level of education are distinct determinants of sterilization among women in South Korea. More studies are needed in order to determine the associations between sterilization rate and decreased fertility.