• 한국지구물리탐사학회:학술대회논문집
• /
• 2003.11a
• /
• pp.501-503
• /
• 2003

Soil-gas radon level and other atmospheric factors have been measured at residual soil profiles that overlie granite bedrock which consists of major geology in Korea for 6 months from November, 2000 to April, 2001. Seasonal variations of soil-gas radon concentration are generally of greater magnitude than day-to-day fluctuations. The highest radon concentrations of 5,131 pCi/L measured during winter season and the lowest radon concentrations of 107 pCi/L during spring season. Two study areas, Bongcheon-dong(granite bedrock) and Seongnam-Yongin(gneiss bedrock) were investigated to assess the radon potential according to their field survey and emanation tests. The mean values of radon decrease in sequentially from Suji-A(813 pCi/L)>Suji-B(757 pCi/L)>Bundang-B(691 pCi/L)>Bundang-A(643 pCi/L)>Bongcheon-dong(513 pCi/L). Estimated soil-gas radon potential using maximum radon emanation ratios of each study area decreases in the order of Bongcheondong(950 pCi/L)>Suji-B(524 pCi/L)>Bundang-A(437 pCi/)>Bundang-B(259 pCi/L)>Suji-A(230 pCi/L) areas. The values of indoor radon and its daughter product concentrations in Bongcheon-dong area show that indoor basement rooms in poor ventilation condition could be classified as extremely high radon risk location of more than 4 pCi/L Rn and 0.02 WL.

• Fashion & Textile Research Journal
• /
• v.22 no.6
• /
• pp.862-872
• /
• 2020

This study explores the effects of facemasks on respiratory, thermoregulatory, cardiovascular responses during exercise on a treadmill and at rest. Five male subjects (25.8 ± 0.8 y, 171.8 ± 9.2 cm in height, 79.8 ± 28.1 kg in weight) participated in the following five experimental conditions: no mask, KF80, KF94, KF99, and N95. Inhalation resistance was ranked as KF80 < KF94 < N95 < KF99 and dead space inside a mask was ranked as KF80 = KF94 < N95 < KF99. The surface area covered by a mask was on average 1.1% of the total body surface area. The results showed no significant differences in body core temperature, oxygen consumption (VO2), carbon dioxide production (VCO2), heart rate or subjective perception among the five experimental conditions; however, cheek temperature, respiratory ventilation and blood pressure were greater for KF80 or KF94 conditions when compared to KF99 or N95 conditions (p<0.05). The differences among mask conditions are attributed to the dead space or specific designs (cup type vs pleats type) rather than the filtration level. In addition, the results suggest that improving mask design can help mitigate respiratory resistance from increased filtration.

• Journal of Environmental Health Sciences
• /
• v.28 no.3
• /
• pp.9-18
• /
• 2002

This study was to observe the occurrence of heterotrophic bacteria in terms of free chlorine residuals in two different water distribution systems belong to both K and Y water treatment plant. The data analyzed in this study showed that in distribution systems(DS), the free chlorine residuals were decreased from 0.10 to 0.56 ㎎/1 for K, and 0.51 and 0.78 ㎎/l for Y The decay of free chlorine were clearly higher in both March and August than those in January. The HPC in DS were ranged from 0 to 40 CFU/ml for K,0 to 270 CFU/ml for Y, on R2A medium. In particular, Its level was relatively high at consumers' ground storage tanks, taps and point-of-end area of Y, The predominant genera found in the distribution systems were Acinetobacter, Sphingomonas (branch of Pseudomonas), Microroccus, Bacillus, Staphylococcus. The diversity of heterotrophic bacteria was increased in the end-point area. Most of them were either encapsulated cells or cocci of gram-positve. In conclusion, the point-of-end area in distribution systems showed that the longer flow distance from WTP the greater diversity and higher level of heterotrophic bacteria due to the significant decay of free chlorine residuals.

• Proceedings of the Korean Society of Medical Physics Conference
• /
• 2004.11a
• /
• pp.49-52
• /
• 2004

A few studies have shown that the function of fusiform face area is selectively involved in the perception of faces including a race difference. We investigated the neural substrates of the face-selective region called fusiform face area In the ventral occipital-temporal cortex and same-race memory superiority In the fusiform face area by the event-related fMRI. In our fMRI study, twelve healthy subjects (Oriental-Korean) performed the implicit distinction of the race while they consciously made familiar-judgments, regardless of whether they considered a face as Oriental-Korean or European-American. In the race distinction as an implicit task, the fusiform face areas (FFA) and the right parahippocampal gyrus had a greater response to the presentation of Oriental-Korean than European-American faces, but in the consciously race distinction between Oriental-Korean and European-American faces, any significant difference in the FFA was not observed. These results suggest that different activation in the fusiform regions and right parahippocampal gyrus resulting from same-race memory superiority could be implicitly taken place by the physiological processes of face recognition.

• Journal of Korean society of Dental Hygiene
• /
• v.23 no.6
• /
• pp.519-527
• /
• 2023

Objectives: This study aimed to investigate the awareness of students majoring in dental hygiene regarding the advanced dental hygiene system for the elderly and people with disabilities. Methods: From September 25 to October 20, 2023, an online survey was conducted with junior and senior students in 27 universities, including eight in the Seoul area, seven in the Chungcheong area, eight in the Yeongnam area, and four in the Honam area. Data analysis methods included frequency analysis, independent t-test, and one-way ANOVA. Results: After graduation, 72.9% of students were willing to work as advanced dental hygienists for the elderly and people with disabilities, and had greater recognition of the system (p=0.042), role (p<0.001), and expected effect (p=0.027) of an advanced dental hygienist than students who were not willing to work in this capacity. Conclusions: It is necessary to introduce a system that recognizes advanced dental hygienists for their expertise in oral hygiene management for the elderly and people with disabilities.

• YAKHAK HOEJI
• /
• v.32 no.5
• /
• pp.362-369
• /
• 1988

Monthly variation of mutagenicity by airborne particulate were studied according to particle size of the particulate. Airborne particulates were collected in Shinchon of Seoul which is commocial and traffic area in 1986. And those were separately collected into two parts such as fine particle (less than $2.5{\mu}m$ aerodynamic diameter) and coarse particle (greater than $2.5{\mu}m$). Extractable organic matters(EOM) were extracted and mutagenicity of the EOM was tested in Salmonella thyphimurium TA 98 by Ames method. While the concentration of coarse particle did not show the seasonal variation, that of fine particle showed great seasonal variation. The contents and mutagenicity of EOM in fine particles were higher than those of coarse particles. So fine particles were expected to contribute to the 90% of mutagenicity in atmosphere by suspended particulates. The content of EOM and mutagenicity by suspended particulates in atmosphere were highest in January all the year around and also higher as much as 6 and 30 times than in July, respectively.

• Journal of Preventive Medicine and Public Health
• /
• v.32 no.1
• /
• pp.9-16
• /
• 1999

Objectives. Few studies have attempted to explain the association between socioeconomic status (SES) and obesity in Korea Especially the studies on same race with different SES at same time are good for SES influence estimation. The present study highlights the influence of SES of parents on adolescent obesity. The subjects are the same race, but live in different areas, with different SES, Seoul and Yangpung in Korea, and Yanbian in China. Methods. The cross-sectional study was conducted in Mar-Jun 1996. We carried out anthropometry, 24 hour-recall diet survey, self-reported questionnaire about sociodemographic characteristics and physical activity. For SES indicators, we used income and education of parents. Results. The relationship between SES of parents, defined as educational status, and obesity in boys in Korea and China is direct, but not significant. The relationship is inverse and nonsignificant among Korean girls, However, for the Korean girls in severe obesity, the relationship is significant. For the Korean-Chinese girls, there is an inverse relationship between the education level and obesity but a direct relationship between the income level of parents and obesity. For the Korean adolescent, there are a direct association between the SES of parents and the nutrients factors such as energy, protein, and fat intake. The energy expenditure of adolescent has no relationship with SES of parents. Conclusion. Among boys, the higher the SES, the greater the risk of obese. Among girls in Korea and Korean-Chinese, on the other hand, the lower the educational status of parents, the greater the risk of obese.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.62 no.6
• /
• pp.51-62
• /
• 2020

The objective of this study was to estimate an optimum ecological flow rate in the Banbyeon stream based on the two representative fish species. Hydraulic stream environment was simulated with HEC-RAS for two water flow regimes and used for the PHABSIM hydraulic simulation. A dominant species of Zacco platypus and an endemic species of Squalidus chankaensis tsuchigae were selected as the representative fishes whose habitat conditions were evaluated for the spawning and adult stages. Weighted usable area (WUA) was estimated based on habitat suitability index (HSI) and PHABSIM habitat simulation. Overall deep water zone in the stream demonstrated greater WUA which implies better habitat status. The estimated WUA for Zacco platypus as the dominant species was about five times greater than Squalidus chankaensis tsuchigae at the stream flow of 12 ㎥/s. The optimum ecological flow rates were 15 ㎥/s and 25 ㎥/s for the respective spawning and adult stages of Zacco platypus, while 5 ㎥/s was estimated for both the life cycles of Squalidus chankaensis tsuchigae. Assuming that the dominant species may survive better in wider flow regimes, the optimum ecological flow rate should be determined rater based on the endemic species and flow rate of 5 ㎥/s was suggested for the Banbyeon stream.

• Journal of Nutrition and Health
• /
• v.38 no.3
• /
• pp.219-225
• /
• 2005

The objective of the study was to define dietary patterns in the representative Korean adult population and to explore their associations with other factors. The Korean National Health and Nutrition Survey was conducted on a stratified random sample (n = 9,968) of the Korean population in 2001. This study analyzed data of 5,721 adult population aged 30 and over. Demographic and lifestyle factors were assessed by questionnaires and food consumption by a 24-h recall method. Cluster analysis identified two dietary patterns with 22 food groups: the larger group that included $85\%$ of total subjects was named as the 'traditional' pattern due to greater intakes of white rice, kimchi, and vegetables, and the smaller group was named as the 'modified' pattern which had greater intakes of noodles, bread, snack, and fast foods. The modified pattern had significantly higher proportion in younger age, higher educational level, residing in metropolitan area, and higher household income. The modified group showed significantly higher intake of all nutrients except carbohydrate. Percent of energy from fat intake, $22\%$ was significantly higher in the modified group than $14\%$ in the traditional group. There were no differences in prevalence of metabolic syndrome and its 5 components among patterns. In conclusion, there were two distinctive patterns that were associated with socio-demographic, nutrient intake, and health risk factors in Korea. It should be considered when designing nutrition policy and intervention program.

• Journal of the Korean Geotechnical Society
• /
• v.32 no.2
• /
• pp.19-30
• /
• 2016

It is well known that water leakage from decrepit sewer pipe mainly causes frequent occurrence of ground subsidence in urban area. Thus, laboratory model tests were carried out to investigate ground behaviour according to location of sewer fracture and various relative densities of surrounding soil. The portion of fractured pipe was assumed to be 20% compared to the circumference of pipe, and to be positioned at the top and bottom of the pipe. Ground conditions were made as loose sand ($D_r=30%$) and dense sand ($D_r=70%$). In addition, comparison and analysis with results of model tests were carried out by Finite Element analysis. As a result, not only water leakage from the bottom of pipe (scenario 2) caused greater ground behaviour than leakage from the top of pipe (scenario 1), but also much greater surface settlement occurred when the ground condition is loose.