• Title/Summary/Keyword: Impedence

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Evaluation of Consolidation Properties in Soft Soils Using Elastic and Electromagnetic Waves (전단파와 전자기파를 이용한 연약 지반의 실내 압밀 특성 평가)

  • Lee, Chang-Ho;Yoon, Hyung-Koo;Kim, Joon-Han;Lee, Jong-Sub
    • Journal of the Korean Geotechnical Society
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    • v.24 no.8
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    • pp.25-34
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    • 2008
  • A new hybrid oedometer cell is designed and manufactured to investigate a behavior of soft soils by using elastic and electromagnetic waves during consolidation test. Bender elements, which generate and detect shear waves, are placed in the top cap and the bottom plate and mounted on the oedometer wall. Double wedge type electrical resistance probe, which measures local void ratio change, is positioned onto the top cap of the oedometer cell. The bender elements and the electrical resistance probe are anchored into a nylon set screw with epoxy resin. The nylon set screw with epoxy resin minimizes directly transmited elastic waves through the oedometer cell due to impedence mismatch and allows for easy replacement of defected bender elements and electrical resistance probe. Primary consolidation time can be estimated from the slope of electrical resistance versus log time curve and the evolution of shear wave velocity. The shear wave velocity can be used to assess inherent anisotropy when disturbance effects are minimized because particle alignment affects the shear wave velocity. The void ratios evaluated by the electrical resistance probe are similar to those by the settlement during consolidation. This study suggests that the shear wave velocity and the electrical resistance can provide complementary imformations to understand consolidation characteristics such as primary consolidation, anisotropy, and void ratio.

Measurement of the Common Carotid Artery by Ultrasound as a Predictor of Atherosclerosis in Obese Adolescents (비만 청소년에서 동맥경화증을 조기에 예측하기 위한 경부 초음파를 이용한 경동맥 측정)

  • Kim, Ye Jin;Shim, Yoon Hee;Yoo, Joung Hyun;Lee, Keun;Hong, Young Mi
    • Clinical and Experimental Pediatrics
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    • v.48 no.7
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    • pp.745-752
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    • 2005
  • Purpose : Adolescent obesity is known to be associated with complications such as hypertension, coronary artery disease and insulin resistance. We measured the common carotid artery by ultrasound as a predictor of atherosclerosis, and investigated the relationship between carotid artery parameters and serum cytokines in obese adolescents. Methods : Twenty-nine obese adolescents(16-17 years old, obesity index>130 percent) and twentyseven normal controls were included. Obesity index and body mass index were calculated from their height and weight. Skin fold thickness was measured at the triceps, and fat mass and fat distribution by bioelectrical impedence analysis. Blood pressure was measured at resting state and serum lipid, insulin, and homocysteine levels after a 12-hour fasting period. Intimal wall thickness, systolic and diastolic diameters of the common carotid artery were measured by ultrasound, and compliance and distensibility calculated by equation. Results : Systolic and diastolic diameters of the carotid artery significantly correlated with arm circumference, body mass index, fat distribution and fat mass. The higher systolic blood pressure was, the larger systolic and diastolic diameter. The higher diastolic blood pressure was, the larger carotid intimal thickness. Insulin levels had positive correlations with systolic, diastolic diameters and serum homocysteine level with intimal thickness. Conclusion : The carotid artery diameter significantly increased with the degree of obesity and blood pressure. The carotid intimal wall thickness significantly correlated with diastolic blood pressure. Measurement of carotid artery thickness, insulin and homocysteine levels might be useful to predict the development of coronary artery disease.

The Clinical Usefulness of Serum Aminotransferase Activities for Predicting Fatty Liver in Obese Children (비만아에서 지방간의 예측 인자로서 혈청 Aminotransferase의 임상적 유용성)

  • Lim, Seon-Woong;Jeon, Myeong-Won;Park, Sin-Ae;Choi, Kyeong-Dan
    • Pediatric Gastroenterology, Hepatology & Nutrition
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    • v.6 no.2
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    • pp.174-182
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    • 2003
  • Purpose: Non-alcoholic fatty liver disease (NAFLD) has been recognized as an important childhood liver disease, especially where the prevalence of childhood obesity is increasing. The purpose of this study is to clarify the usefulness of elevated serum aminotransferase activities and their ratio for predicting the presence of fatty liver and its severity in obese children. Methods: Forty-four children (M/F 29/15, age 4 to 16 years) with obesity (weight excess>20%) were analyzed retrospectively with medical records based on degree of obesity, bioelectrical impedence, serum aminotransferase activities, lipid profiles and ultrasonography. Results: 1) Ultrasonography was carried out in 34 cases. Elevated serum ALT was found in 89.7% (26/29) of the patients diagnosed as fatty liver by ultrasonography and decreased AST/ALT ratio (<1) was found in 96.6% (28/29). There was a strong correlation between elevated serum ALT (>45 IU/L) or decreased AST/ALT ratio (<1) and the fatty liver in obese children (p<0.05). 2) There was no significant correlation between the serum ALT or AST/ALT ratio and the degree of fatty liver (p>0.05). 3) There was a significant correlation between total cholesterol, triglyceride and fatty liver (p<0.05). Conclusion: Serum ALT activity and AST/ALT ratio were useful to predict the presence of fatty liver diagnosed by ultrasonography in obese children, whereas they were not useful to predict the degree of fatty liver. Therefore, to prevent fatty liver progressing to advanced liver disease, it is necessary to manage and monitor the obese children continuously, especially those who have predicting factors of fatty liver.

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The Relationship of $VO_2$Max/Min in Cardiopulmonary Exercise Test and Fat Distribution (운동부하심폐기능검사상의 분당최대산소섭취량과 체내 지방분포와의 상관관계)

  • Choi, Jae-Chol;Jee, Hyun-Suk;Park, Young-Bum;Park, Sung-Jin;Yoo, Jee-Hoon;Kim, Jae-Yeol;Park, In-Won;Choi, Byoung-Whui;Hue, Sung-Ho
    • Tuberculosis and Respiratory Diseases
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    • v.49 no.4
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    • pp.495-501
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    • 2000
  • Background : Cardiopulmonary exercise test is a useful test for the evaluation of the cardiovascular and respiratory systems. Obese subjects have an increased resting metabolic rate ($VO_2$) compared to non~obese subjects and the increase is more marked during dynamic exercise, which results in the limitation of maximal exercise in obese subjects. In this study, the influence of the obesity and fat distribution on the maximal exercise capacity were evaluated. Methods : Maximal exercise capacity was represented by maximam maximum oxygen uptake and $VO_2$ max in the cardiopulmonary test. Obesity, total fat content and abdomina1 obesity(waist to hip ratio, WHR) were measured by bioelectrical impedence method. Total of 42 volunteers (male 22, fema1e 20) were evaluated. Results : 1) Weight to height ratio (mean$\pm$SD) was 110$\pm$14.9% in men and 100$\pm$11.1% in women. 2) Fat ratio (mean$\pm$SD) was 23.3$\pm$5.2% in men and 27.55$\pm$3.9% in woman. 3) Waist to hip ratio (mean$\pm$SD) was 0.85$\pm$0.04 in men and 0.8$\pm$0.03 in woman. 4) In men, $VO_2$ max/min/Kg was negatively correlated with obesity, fat ratio, and abdominal fat distribution. 5) In woman, $VO_2$ max/Kg was negatively correlated with obesity and fat ratio, but did not show significant relationship with abdominal fat distribution. Conclusion : Obesity was a limiting factor for maximal exercise in both men and women. Abdominal obesity was a limiting factor for maximal exercise in men but its implication to women needs further evaluation.

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The Clinical Usefulness Measurement of the Whole Body Percent Fat Calculated by the Part Bone Mineral Density Measurement (부분골밀도 측정을 통해 산출되는 체지방률의 임상적 유용성에 대한 평가)

  • Kang, Young-Eun;Kim, Eun-Hye;Kim, Ho-Sung;Choi, Jong-Sook;Choi, Woo-Jun
    • The Korean Journal of Nuclear Medicine Technology
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    • v.15 no.1
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    • pp.3-9
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    • 2011
  • Purpose: Generally dual energy X-ray absorptiometry has been used for the purpose of evaluation of osteoporosis and treatment. Recently the interest of obesity came to be high and body percent fat test is increasing. Existing measure of body fat have to scan the whole body can be evaluated, but only lumbar spine and hip measurements was assumed to be whole body fat as well as improving the software. It tries to check whether the part measured value not being whole body measurement has the validity or not compared with the value calculated with the method that it is different, it forgives through a correlation with a (BIA) and (BMI). Materials and Methods: In 2010, the body percent fat was measured among the examinee coming to the Asan Medical Center public health care center from March till August against 90 females more than 40 years old through (DXA) and BIA. BMI utilized the value which wrote an hight and weight measured through the body measuring instrument in the examinee information and is automatically calculated. In addition, it classified as the low weight ($13-18.5kg/m^2$), normal ($18.5-25kg/m^2$), and corpulence ($25-30kg/m^2$) based on BMI and so that it could check whether there was the difference according to the weight or not BMI and BIA and correlation between DXA were analyzed in each group. The statistical program for the analysis used SPSS 12.0. Results: The comparison of DXA at 3 which it divides into the low weight and normal and corpulence groups and BIA did not show the difference noted statistically in all groups and the between group comparison was exposed to do not have a meaning. The body percent fat measured by the correlation analysis result DXA at the state that it doesn't divide into the group showed the high correlation (r=0.908, p0.01) noted statistically compared with BMI and showed the high correlation noted statistically in a comparison with BIA (r=0.927, p0.01). Conclusion: It confirmed that the whole body percent fat presumed from the part bone density measurement showed the excel correlation compared with BIA and BMI and information is high. There is still no clear standard about the presumed whole body percent fat and it is difficult to evaluate the fat evaluation by the bone mineral density measurement. However, it is determined that the information offering which is more objective through the comparative study with the body percent fat which is very efficient and in that it can obtain till the information about a fat as well as diagnosis of the osteoporosis through the bone density checkup is measured by the afterward telegraph bone density checkup and is clinically useful is possible.

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Nutritional and Health Status of the Elderly Living in Songnam - I. Anthropometric Measurements and Biochemical Nutritional Status - (성남지역 노인의 영양 및 건강상태 조사 I. 신체 계측 및 생화학적 영양상태)

  • 권종숙;이홍재
    • The Korean Journal of Food And Nutrition
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    • v.16 no.4
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    • pp.310-320
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    • 2003
  • To study the nutritional and health status of the elderly in Songnam, the anthropometic measurments, fat composition of body(FAT), blood pressure(BP) and blood test for analyzing biochemical indies of the elderly in seongnam were carried out in 338 free-living elderly (161 men, 177 women) aged from 58 to 92. Anthropometric measurements and blood pressure were assessed, and body fat was analyzed by BI(Bioelectrical Impedence) method. Biochemical measurements including blood glucose(BG), GPT, serum total cholesterol(TC) and albumin(AL) were analyzed. Average heights of the subjects were lower than the standards established in the Korean Recommended Dietary Allowances, and average weights were similar to the standards. FAT were significantly higher in women(36.4%) than men(27.7%), and both groups showed higher values than the reference. Mean systolic BP levels of men and women were 153.3mmHg and 153.7mmHg, and diastolic BP levels were 87.5mmHg and 86.0mmHg, respectively, and there were no significant differences between the sex. Mean BG levels of men and women were 115.9mg/㎗ and 123.7mg/㎗, respectively, and there were no significant differences between the sex and among the age groups. Mean GPT levels of men and women were 19.4unit and 18.1unit, respectively, and women older than 75 years showed significanly low levels of GPT compared to other women's age groups. Mean TC levels of men and women were 186.0mg/㎗ and 206.6mg/㎗, respectively, and significantly higher TC levels were shown in women than men. Mean AL levels of men and women were 4.8g/㎗ and 4.8g/㎗, respectively, and men aged 50 ∼ 64 years showed significant high AL levels compared to other age groups of men. It was suggested that nutrition education program was a good way to improve health status of the elderly.