• Journal of the East Asian Society of Dietary Life
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• v.20 no.1
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• pp.175-186
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• 2010

This study was conducted to investigate the body weight control, attitudes, lifestyles and dietary habits according to the obesity index of elementary school students. This study utilized questionnaires and body composition measurements collected with a bio- electrical impedance analyzer(Inbody 4.0). Specifically, differences between the underweight group, normal group, and overweight group were tested by a $x^2$-test or ANOVA and Duncan's multiple range test. The subjects consisted of 571 elementary school students residing in Chonbuk Province. The average age, height, weight, and BMI of the male subjects was 11.5 years, 150.0 cm, 45.2 kg and $20.0\;kg/m^2$, respectively. The average age, height, weight, and BMI of the female subjects was 11.5 years, 152.2 cm, 46.1 kg and $19.8\;kg/m^2$, respectively. Twenty percent of the subjects were in the underweight group, 52.2% were in the normal weight group, and 27.8% were in the overweight group according to the Korean Pediatrics Society standards. A total of 50.2% of the subjects were dissatisfied with their body weight, while 36.8% of underweight, 42.3% of normal weight, and 81.1% of overweight subjects were dissatisfied with their weight. Fifty two percent of the subjects had attempted to reduce their body weight, including 50% of the normal weight group. The main reason for wanting to reduce body weight was to maintain health. The percentage of subjects who had received body weight control education was 41.3%, but 77.6% of the subjects thought it was necessary. Poor time management, lack of physical activity, portion size of meals, unbalanced diet, frequent consumption of convenience foods, and frequent snacking all affected the obesity index. Overall, the results of this study indicate that it is necessary to develop weight control programs for all elementary school students who are underweight, normal weight, and overweight.

• Korean Journal of Community Nutrition
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• v.12 no.4
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• pp.477-488
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• 2007

Prevalence of an obese population has been increasing in Korea. Obesity is considered a major risk factor for chronic degenerative diseases. Specifically, prevalence of obesity is prominent for adult woman in Korea. In many weight control programs, weight change did not often show any beneficial effects for health. These facts discourage people in the program. Thus in this study, the anthropometry, blood pressure, serum biochemical indices and dietary habits were compared by percent body fat change for adult women to show the beneficial effects of the weight control program. Study subjects were 134. Measurements were done before and after the weight control program. Percent Body Fat (PBF) was measured by bioelectrical impedance analysis. Using PBF changes, subjects were grouped as I (more than 1% increase), M (${\pm}1%$ change), and D (more than 1% decrease). Data were analyzed using SPSS 12.0 program. Among the 134 participants, 13 increased their weight and 100 decreased. For PBF, 19 increased and 59 decreased. Statistical significant differences were shown for anthropometric assessments before and after for all weight, fat mass, percent body fat, waist-hip ratio and body mass index. I had increases, and D shows decreases. But the difference of D is large than M. Systolic and diastolic blood pressures decreased in all groups (p < 0.05). Fasting blood glucose decreased in all groups but were statistically significant only in D. Also triglyceride decreased in D (p < 0.05). Thus health conditions showed desirable changes in I < M < D in order. Dietary habit changes were desirable with only D. Weight, BMI and other indicators for obesity is not the real indicator for PBF. Recently it is easy to measure PBF. Thus, for weight control programs and to show benefits of the program, PBF is a good indicator for adult women in Korea.

• Journal of the Institute of Electronics Engineers of Korea TC
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• v.48 no.9
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• pp.47-53
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• 2011

The signal transmission properties of the connector such as insertion loss and return loss are investigated using analysis procedure of S-parameter simulation, equivalent model extraction, and characteristic impedance calculation. S-parameter simulation is performed by connector's modeling and solving based on 3-dimensional finite element method. The connector's equivalent model of ${\pi}$ type is are proposed and extracted with an optimization process of circuit analysis simulator. The characteristic impedance of the connector is calculated with results of circuit analysis simulation and S-parameter data. According to the connector's characteristic impedance, it's revised design is carried out. In this work, the connector's effective contact area is increased and its body is applied as a high dielectric material in order to increase its capacitance and then obtain impedance matching. Therefore, return loss of the connector is improved by approximately 10 dB due to its design revision.

• Journal of Community Nutrition
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• v.6 no.3
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• pp.121-124
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• 2004

Objective : The paper aims to provide predictive coefficients via BIA for the assessment of body composition in children and adolescents to serve clinical as well as research purposes. Methods : Body composition via dual-energy x­ray absorptiometry (DXA) and bioelectric impedance as well as other anthropometric index were derived from meaurements on 1026 children and adolescents aged from 6 to 18 years from Beijing City. The best subset regression and principle component analysis were adopted to build the predictive coefficients with the logarithm of body composition via DXA as response variable. Results : Condition index ${\varphi}$ of fat-free mass multiple linear regression achieves 113.49 and 91.18 for males and females respectively, demonstrating severe multicollinearity among anthropometric indexes in children and adolescents. BIA predictive coefficients base on the best subset regression and principle component analysis boast a content predictive value for lean mass ($r^2$ = 0.9697 and 0.9664 for boys and girls respectively, p < 0.0001) and for Fat$\%$ ($r^2$ = 0.7705 and 0.6959 for boys and girls respectively, p < 0.0001). Conclusions : BIA method is applicable for the prediction of body composition for children and adolescents.

• Biomedical Science Letters
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• v.16 no.3
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• pp.169-177
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• 2010

Osteoporosis is a disease that increases the fracture rates and a major cause of increased mortality and morbidity in the elderly people. This study is to determine which components of body composition and metabolic syndrome risk factors are important to bone health, we analysed the relationship among bone mineral density (BMD), body composition and metabolic syndrome risk factors in females. Totally 630 females participated in a medical check-up program (mean age 47 years) were selected for this study. Body composition analysis was performed by segmental bioelectrical impedance method, muscle mass, and percent body fat were measured. We also measured metabolic syndrome risk factors including abdominal obesity, HDL-cholesterol, triglyceride, blood pressure and fasting glucose level. Metabolic syndrome was defined by NCEP-ATP III criteria. The lumbar spine and femoral neck BMD were measured using the dual energy X-ray absorptiometry. Osteopenia and osteoporosis were observed in 180 and 51 persons, respectively. Muscle mass and HDL-cholesterol decreased in osteopenia and osteoporosis groups compared to the control group, and the grade was shown progressively by the symptoms. Significant positive correlation between BMD and muscle mass was observed. Multi variable regression analyses showed that % body fat and muscle mass were independent predictors of BMD after adjustment of age, height and weight. In conclusion, the BMD showed negative correlation with the metabolic and body composition was associated with BMD.

• Journal of the Korean Institute of Telematics and Electronics B
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• v.32B no.7
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• pp.1010-1024
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• 1995

An intelligent trajectory control method that controls a direction and a average velocity for a prosthetic arm by force and direction estimations using EMG signals is proposed. 3 stage linear filters are used as a real time joint trajectory planner to minimize the impact to human body induced by arm motions and to reduce muscle fatigues. We use combination of MLP and fuzzy filter for a limb direction estimation and a time model of force for determining a cartesian trajectory control parameter. EMG signals are acquired by using a amputation simulator and 2 dimensional joystick motion. Simulation results of the proposed method show that the arm is effectively followed the desired trajectory by estimated foreces and directions. This method reduces the number of electrodes and attatched sites compared with the method using Hogan's impedance control.

• Journal of Korean Medicine for Obesity Research
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• v.5 no.1
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• pp.21-29
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• 2005

Objectives : This study was carried out to evaluate the difference of body mass index(BMI) distribution and the difference of effect of weight reduction program among Sasang constitution. Methods : Sasang constitution was differentiated by QSCC II of 875 cases. Body composition was analysed by bioelectrical impedance analysis(Inbody 3.0, Biospace, Seoul, Korea) in before and after treatment to evaluate the effect among Sasang constitution. The weight reduction program including very low calorie diet, electrical acupuncture and herbal medicine was treated to all cases equally during 1 month. Results and Conclusions : The group of Taeum was more obese and less reducted in body fat mass and % body fat in tools of percent rates of the changes than other type of Sasang constitution. In conclusion, the group of Taeum is more easy to become obese and more difficult to treat obesity

• Proceedings of the KIPE Conference
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• 2016.07a
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• pp.353-354
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• 2016

본 논문은 IEC 60479 표준 "인체감전의 생리학적 현상"에 제시되어 있는 인체감전 현상에 대하여 교류환경과 직류환경에서 인체임피던스의 특성을 실험을 통하여 분석한다. 연구 결과, 적어도 상용주파수 이하에서는 IEC 60479 표준에서 제시하는 인체 임피던스 모델의 수정이 필요함을 발견하였다. 또한 도출된 실험 결과를 활용하여 직류 배전시스템의 TN 접지방식에서 인체 감전 및 설비 누전에 따른 사고에 대하여 구분동작이 가능한 직류전용 누설전류 검출(DC Residual Current Detection) 기법을 제안한다.

• Transactions of the Korean Society of Automotive Engineers
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• v.21 no.2
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• pp.159-165
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• 2013

ESD damage by Charged Cable Model (CCM) is introduced. Due to its own impedance characteristic unlike Human Body Model (HBM) or Machine Model (MM) electric component can be destroyed even though it is located after typical protection circuit. Possible mechanism of ESD damage to automotive electric control unit (ECU) in vehicle environment by CCM discharge was investigated. Based on investigation, field-returned vehicle whose ECU is expected to be damaged by CCM discharge was tested to reproduce it and similar electric component destruction inside ECU was observed. Suggestions to reduce the possibility of ESD damage by CCM are introduced.

• Korean Journal of Community Nutrition
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• v.3 no.2
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• pp.190-201
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• 1998

This study was carried out with 505(243 boys and 262 girls in the Sungnam area) high school students to investigate the effects of eating behavior and anthropometric variables of weight and height on excercise performance. General characteristics about subjects and eating behavior were surveyed by questionnaire, anthropometric data were collected using two methods. The weight and height of subjects in 1996 were measured, but the same data in 1995 were collected from health records of each student. Body fat content of subjects was measured by BIA(Body Impedance Analysis). The grades of exercise performance, which were evaluated by physical education teachers were collected from records of a physical strength test score of each subject. From these, the following result were found. Groups with different eating behaviors such as skipping meals, overeating, food preference for a specific food(milk, carbonated drink etc.) were significantly different in their weight and height and body fat contents. The growth rate of height in first and second grade boys was significantly higher than that for grade boys. The amount of weight gain from second grade to third grade was significantly more than that of other grades both for boys and girls. The mean of BMI was $21.66\pm{2.95}$ in boy, $21.50\pm{2.62}$ in girls. The percentage of body fat was $24.91\pm{6.55%}$ in boy $34.73\pm{4.88%}$ in girls. Amounts of body fat were significantly increased in third grade. The group with higher fat content and the higher BMI group had lower values of physical strength. And the ability to exercises perform decreased significantly by promotion of grade. The other variables such as degree of concern about weight control and preference of exercise, and frequencies of exercise per week were significant factors in body fat content and physical strength. As a countermeasure for these problems, nutrition and health education must be developed for adolescents and a practical, proper physical activity guidance campaign for them is necessary.