• 한국방재학회 논문집
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• 제6권3호
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• pp.57-68
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• 2006

본 연구에서는 강우의 수문학적 특성을 고려하여 단시간강우의 시간분포를 분석하고, Huff의 무차원 누가곡선을 제시하였으며, 강우의 수문학적 특성은 지속기간, 강우의 발생원인(장마, 태풍, 집중호우, 전선형강우), 구간변화 등으로 분류하였다. 본 연구의 수행으로 인해 얻어진 결과를 요약하면 다음과 같다. 첫째, 국내 도시지역의 단시간 강우의 최대강우강도는 전방위구간에서 발생할 확률이 가장 높게 나타났으며, 둘째, 강우발생원인별 분류에서도 전반적으로 전방위구간에서 최대강우강도가 발생하였으나 태풍의 경우에는 후방위구간에서 최대강우강도가 발생하였다. 셋째, Huff의 6구간 분석에서는 동일한 위치에 해당되는 제2구간에서 우세하였다. 넷째, 전기간 강우자료를 이용한 기존 연구들의 무차원 누가곡선 및 특성변수와의 비교를 실시하여, 수문학적 특성에 따라 무차원 누가곡선의 위치 및 특성변수의 값에서 차이가 발생한다는 것을 알 수 있었다.

• 한국환경보건학회지
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• 제45권6호
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• pp.583-593
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• 2019

Objectives: The purpose of this study was to evaluate the relationship between the frequency score of wearing personal protective equipment (PPE) and concentration of urinary organophosphorus pesticide metabolites in farmers. Methods: The study was conducted in Chungcheongnam-do Province of South Korea. We collected urine samples from 308 farmers from September to December 2017 and May to July 2018. Among them, 17 farmers with urinary creatinine levels outside the normal range were excluded. Information on the frequency of wearing PPE was obtained from the farmers through face-to-face survey. Each frequency of wearing for seven types of PPE was converted into a score and expressed as a total score, which was divided into quartiles. Four types of urinary organophosphorus pesticide metabolites were analyzed using a gas chromatography mass selective detector. Multiple linear regression analysis was used to identify concentrations of urinary organophosphorus pesticide metabolites affected by the frequency of wearing PPE. Results: The average frequency score of wearing PPE was 8.0. The quartiles of frequency score of wearing PPE were divided as follows: 1st quartile (≤1), 2nd quartile (1-6), 3rd quartile (6-12), and 4th quartile (>12). Compared with subjects with a low frequency score of wearing PPE (reference), subjects with a high frequency score of wearing PPE (4th quartile) had lower concentrations of urinary diethyl phosphate (DEP) (p<0.01) and dialkyl phosphate (ΣDAP) (p<0.05), which is the sum of dimethyl phosphate (DMP), DEP, dimethyl thiophosphate (DMTP), and diethyl thiophosphate (DETP). Conclusion: Concentrations of urinary organophosphorus pesticide metabolites were associated with frequency score of wearing PPE. Particularly as the frequency score of wearing PPE increased, concentrations of urinary DMP, DEP, DETP, and ΣDAP significantly decreased. The findings of this study can contribute to the management of health effects among farmers working with pesticides.

• Journal of Yeungnam Medical Science
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• 제36권2호
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• pp.141-147
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• 2019

Background: The present study aimed to evaluate the clinical association between cadmium exposure and hearing impairment among the Korean population. Methods: This retrospective cross-sectional study used the data obtained from the Korean National Health and Nutrition Examination Survey were used for our study. Finally, 3,228 participants were included in our study, which were then divided into quartiles based on their blood cadmium levels: first quartile (1Q), second quartile (2Q), third quartile (3Q), and fourth quartile (4Q) groups. The hearing thresholds were measured using an automatic audiometer at 0.5, 1, 2, 3, 4, and 6 kHz. Hearing loss (HL) was defined as >25 dB average hearing threshold (AHT). Results: All the groups had 807 participants each. The area under the receiver operating characteristic curves of cadmium level for HL were 0.634 (95% confidence interval [CI], 0.621-0.646). The participants in the 4Q group had higher Low/Mid-Freq, High-Freq, and AHT values than those in the other groups in the multivariate analysis after adjusting for confounding factors. The logistic regression showed that the OR for HL per $1{\mu}g/L$ increase in cadmium was 1.25 (95% CI, 1.09-1.44; p=0.002) on the multivariate analysis. Moreover, the multivariate logistic regression analyses revealed that the participants in the 4Q group exhibited a 1.59-, 1.38-, and 1.41-fold higher odds for HL than those in the 1Q, 2Q, and 3Q groups, respectively. Conclusion: High cadmium level quartile was associated with increased hearing thresholds and HL among the Korean adult population.

• 토지주택연구
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• 제14권4호
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• pp.17-37
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• 2023

전체 주택 시장에서 보증부 월세시장이 차지하는 비중은 전세 지분을 잠식하며 지난 30년 간 지속적으로 증가하여(1990년 8.2% → 2020년 21.0%) 2.6배로 확대되었다. 월세 부담 분포는 공공임대 월세 지원의 확대와 고가 월세의 등장으로 월세시장 재편으로 이어지고 있다. 월세 가구의 소득 분포는 저소득 월세 가구의 소득 둔화와 고소득 월세 가구의 출현으로 양극화가 진행되고 있다. 이에 본 연구는 보증부 월세시장을 통해 월세시장의 구조적 변화와 소득-임대료 간 부정합 현상을 정량화하는 지표로 월세 가구의 임대료와 소득을 동시에 비교하여 그 추이를 측정하였다. 11개년도(2006~2021년) 주거실태조사 마이크로데이터를 이용하여 2006년(기준연도) 월세 임대료(전월세 전환율 반영)와 월세 가구 소득을 각각4분위 분포로 구획한 후 10~15년 후(분석연도) 나타난 변화를 전국과 16개 광역시·도(세종시 제외) 공간 단위에서 분석하였다. 그 결과, 전국적인 월세 주택 공급에서 최고가 4분위(25% → 18%)와 3분위(25% → 20%)의 축소로 중·상위 월세 주택 공급난을 보인 반면 공공임대주택 공급으로 2분위(25% → 28%)와 최저가 1분위(25%→ 35%)는 확대되었다. 월세 가구의 수요 측면에서 최고소득 4분위(25% → 21%)의 축소와 달리 최저소득 1분위(25% → 31%)는 확대되었다. 16개 광역시·도를 비교해보면, 월세 임대료와 월세 가구소득의 변화 방향과 강도에 있어서 지역 간 상당한 격차가 확인되었다. 특히, 서울의 월세 주택 시장은 공급 양극화로 서울 월세 가구의 소득 분포와 불균형을 이루었다. 아파트 월세시장의 구조적 변화 양상은 비아파트 월세시장과 차별화되었다. 본 연구의 결과는 향후 지역별 월세 주택 시장에서 보증부 월세 가구의 소득 분위별로 부담 가능한 임차 주택 재고를 확보하고 지역별 소득과 임대료 분포 간의 균형을 유지할 수 있는 주거안정 방안을 마련하는데 기초자료로 활용될 수 있을 것이다.

• Journal of Electrical Engineering and Technology
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• 제11권1호
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• pp.93-99
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• 2016

The present study aims to increase the amount of surface flux by changing the magnetic directions of a spherical magnet (NdFeB) consisting of four poles. For this purpose, the magnetic directions of quartile spherical slices constituting the spherical magnet are manipulated and their three-dimensional analyses are carried out by using finite-element method via Maxwell environment. The analysis of the magnetic quartile spheres with four different magnetic directions are compared to the each other, and then the quartile sphere with the best surface flux distribution is suggested for rotor structure. It is clear emphasized that the induced torque of the spherical motor, in which such a rotor is used, will be improved as well.

• Clinical and Experimental Pediatrics
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• 제61권4호
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• pp.121-128
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• 2018

Purpose: Obesity has been associated with higher total blood mercury levels, based on animal studies; however, studies that focus on children and adolescents are lacking. We aimed to assess the association between total blood mercury levels and the incidence of overweight and abdominal obesity in Korean adolescents. Methods: The study population comprised 1,567 adolescents (793 boys and 774 girls; aged 10-19 years), who participated in the Korea National Health and Nutrition Examination Survey 2010-2013. We analyzed total blood mercury levels according to obesity status in all participants. Results: The geometric mean of total blood mercury levels was $1.93{\mu}g/L$. Participants with overweight ($2.20{\mu}g/L$) and obesity ($2.17{\mu}g/L$) had higher levels than those with normal weight ($1.86{\mu}g/L$, P<0.0001). The prevalence of overweight significantly increased with elevation of the total blood mercury quartile in both sexes. Increased incidence of abdominal obesity corresponding to increased total blood mercury level was observed in boys. After adjusting for covariates, those in the highest total blood mercury quartile were found to be at higher risk of overweight/obesity than those in the lowest quartile in both sexes (odds ratio [95% confidence interval]: boys, 3.27 [1.66-6.41]; girls, 1.90 [1.03-3.49]). The association between total blood mercury quartile and abdominal obesity was significant after controlling for covariates in boys (2.35 [1.05-5.24]). Conclusion: Our results suggest an association between total blood mercury levels and overweight in Korean adolescents.

• Nutrition Research and Practice
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• 제7권5호
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• pp.409-417
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• 2013

This study was performed to determine the effects of dietary calcium (Ca) intake, milk and dairy product intake, and serum vitamin D level on bone mineral density. The survey data from the 2008-2009 Korea National Health and Nutrition Examination Survey (KNHANES) for adults (3,819 males, 5,625 females) aged > 20 years were examined; osteoporosis was defined according to the standards for Asian populations (T-score < -2.5). The risk for osteoporosis significantly decreased as Ca intake increased; this effect persisted (quartile 4 vs. quartile 1 of Ca intake: odds ratio [OR] 0.66; 95% confidence interval [CI]: 0.50-0.87) even after adjustment for gender, age, and other factors (body mass index, serum vitamin D, menstruation, female hormone intake, menopausal status, and the number of days per week of muscular strength exercise). Additionally, the risk for osteoporosis significantly decreased as the Ca/P ratio increased (quartile 4 vs. quartile 1: OR 0.76; 95% CI: 0.58-0.98). The degree of risk was 0.96 (0.66-1.38) in those who consumed < 1 portion of milk or dairy products daily, and 0.71 (0.53-0.96) in those who consumed > 1 portion per day, compared with those who had zero intake. The risk for osteoporosis significantly decreased as the serum 25(OH) vitamin D level increased. From these results, we advocate an increase in Ca, milk, and dairy product intake, and that serum 25(OH) vitamin D levels be maintained within the normal range, for the maintenance of bone health and the prevention of osteoporosis in adults.

• Journal of Nutrition and Health
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• 제39권8호
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• pp.832-840
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• 2006

This study was performed to investigate the relationship between diet quality and food cost and identify the effects of food cost on healthy diet among Korean adult. Among the subjects of 2001 National Health and Nutrition Survey 1,641 men and 1,765 women aged from 30 to 49 years were selected and their information of dietary intakes, socio-demo-graphic information, and anthropometric data were analyzed. For the analysis, subjects were classified to quartile based on their daily food cost. Food guidelines provided by Korean Nutrition Society was regarded as a model of healthy diet. Subjects in the lowest quartile of food cost consumed inadequate amount of food from all food categories of the guidelines. Many subjects in the highest quartile not only satisfied the recommended amount of the Food Guide but also seemed to overeat high energy density foods. Even in the highest quartile, about 90% of subjects did not satisfied recommended amount of dairy products. According to the calculated cost of healthy diet, the average cost did not seem to be more expensive than the current mean food cost of the subjects, and most cost-sensitive food intake was observed in the meat fish beans eggs category. The implications of study results were: 1) all the high cost diets did not indicate the high quality of diet, 2) most practical matter of healthy diet in low income group seemed whether they could afford the expense of meat and fish, 3) nutrition education was required to most subjects for healthy diet.

• 한국식품영양학회지
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• 제30권1호
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• pp.74-82
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• 2017

This study was conducted to evaluate the risk of overweight and obesity in adolescents consuming snacks frequently from 2007~2009, Korean National Health and Nutrition Examination Survey (KNHANES). The subjects (12~14 years: n=523; 15~18 years: n=614) were presented with food frequency questionnaires, and they were classified according to their gender and frequency of snack consumption. In the age group of 12~14 years, boys and girls (boys OR: 1.11, 95% CI: 0.52~2.39, girls OR: 12.45, 95% CI: 2.26~68.51) who consumed yogurt frequently had a higher risk of overweight and obesity at the highest quartile frequency compared with the lowest quartile after adjustments for multiple confounding factors, including age, physical activity, frequency of eating out and snack consumption, and energy intake. In the age group of 15~18 years, girls (OR: 1.01, 95% CI: 0.34~2.99) consuming fried foods had a higher risk of overweight and obesity at the highest quartile frequency compared with the lowest quartile after adjustments for multiple confounding factors, including age, physical activity, frequency of eating out and snack consumption, and energy intake. Thus, we conclude that frequent consumption of yogurt and fried foods increases the risk of overweight and obesity in adolescents. These findings suggest that the risk of overweight and obesity is associated with the frequency of snack consumption.

• Journal of Nutrition and Health
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• 제36권2호
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• pp.167-174
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• 2003

This study investigated associations between nutrient intake, lumbar bone mineral density (BMD) , and bone mineral content (BMC) among 33 ovariectomized women (mean age =47.2 y) . Forty-five premenopausal women participated as a control group. The BMD and BMC of the lumbar spine (L$_2$-L$_4$) were measured by dual energy x-ray absorptiometry. Nutrient intake was estimated by the convenient method and a quantitative food frequency questionnaire was designed for this study that included the most commonly consumed foods sources of calcium. Participants were asked to identify all daily physical activities, and the number of hours per activity. The participants were also grouped by calcium intake. The total calcium intake of all participants was estimated by dietary calcium intake and then the subjects were divided into quartiles to assess the lumbar BMD and BMC of the highest quartile and the lowest quartile of calcium intake. The ovariectomized women consumed 602 mg/d of calcium which is 86% of RDA. There were significant differences in lumbar BMD and BMC between control and ovariectomized group. Within ovariectomized group the highest quartile calcium intake group had significantly greater lumbar bone mineral density and bone mineral content than the lowest quartile calcium intake group. Correlation analysis revealed that the ALP was positively associated with calcium index in control women, while ALP was positively associated with energy intake in ovariectomized women. And body weight was positively correlated with the spinal BMD and BMC in all women. The spinal BMD was negatively associated with menarche age, number of child, and the age of last child delivery, and age in control women. However, neither menarche age nor the age of last child delivery were associated with both spinal BMD in ovariectomized women. These results confirmed that ovariectomized and low calcium intake is associated with poor bone mineral density. Energy and calcium intake and adequate body weight should be recommended in ovariectomized women to prevent osteoporosis.