• Journal of Life Science
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• v.20 no.4
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• pp.535-542
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• 2010

This study was carried out to examine anthropometric parameters and related habits in female college students. Mean age, height, and body weight of the subjects in total (n=212) were 20.7 yrs, 161.8 cm, and 53.5 kg, respectively. Anthropometric parameters were measured by bioelectrical impedance analysis. Mean degree of obesity, body mass index (BMI), and waist-hip ratio (WHR) were 98.4%, $20.6\;kg/m^2$, and 0.80 respectively. Surprisingly, 63.7% of the subjects showed unbalanced weak upper bodies compared to their lower bodies. Therefore, they were divided into two groups: unbalanced weak upper body group (UU, n=135) and balanced upper body groups (BU, n=77). Bodyweight, degree of obesity, BMI, and WHR in the UU group were significantly lower than those in the BU group. Amounts of body protein, body fat, and body mineral in the UU group were also significantly lower than those of the BU group. Mid-arm muscle circumference of the UU group ($18.5{\pm}0.8\;cm$) was significantly lower than those of BU group ($20.4{\pm}1.2\;cm$), although mid-arm circumference of the UU group was not significantly different compared to those of the BU group. On a questionnaire on exercise habits, 1.5% of the UU group and 7.8% of the BU group answered that they exercised regularly, and 55.5% of the UU group and 31.2% of the BU group reported that they never exercised (p<0.01). Even in the subjects who exercised, the duration of the exercise was not sufficient because 38.4% of the UU group and 35.8% of the BU group answered that they exercised for less than 30 min. In conclusion, interventions in exercise habits may be needed for female college students who have unbalanced weak upper bodies.

• Journal of Advanced Marine Engineering and Technology
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• v.35 no.8
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• pp.1117-1123
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• 2011

Ungrounded power systems are adopted onboard vessels which enable more stabilized power supply even in case of electric leakage to hull. If earthing faults happen at these systems, they make grounding impedances of power lines unbalanced each other on the three phases, resulting in high voltages to hull which can bring more possibilities of electric shocks and electric fires. This study focuses on how to configure a calculation module for transferring a grounded condition by lowered insulation resistance into a vector diagram of the voltages to hull. By using the module, the loci of neutral points were acquired to analyze how voltages to hull are affected by earthing faults and the distributed capacitances between power lines and hull. The suggested module was simulated and compared to the measured values from a test power system in good results.

• 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.

• The Journal of Korean Institute of Electromagnetic Engineering and Science
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• v.25 no.3
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• pp.319-332
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• 2014

Insertion loss is used as the character to express the efficiency of EMI filter. In this paper, we studied the better method that can measure the insertion loss of EMI filter exactly than the original method. For the achievement of this, the method measuring both common mode(CM) and differential mode(DM) insertion loss with arbitrary input/output impedance is accomplished using a 4-ports S-parameters system for consideration of unbalanced factor. Using this method, when input/output used in specific system is known, CM/DM insertion loss of EMI filter inserted in the system can be calculated. Finally, we applied 4-ports modeling method to 'X/Y capacitor part' and suggested the algorithm for selecting suitable the value of Y-capacitor using mixed mode S-parameters and mixed mode chain S-parameters.

• Journal of the Korean institute of surface engineering
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• v.38 no.4
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• pp.137-143
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• 2005

CrSiN coatings of stepwise changing Si concentration were deposited on stainless steel by closed field unbalanced magnetron sputtering (CFUBM) system. Microstructure of the films due to the Si concentration is measured by XRD. The corrosion behavior of CrSiN coatings in deaerated $3.5\%$ NaCl solution was investigated by potentiodynamic test, electrochemical impedance spectroscopy (EIS) and surface analyses. The microstructure of CrSiN film depends on the Si concentration. When Si/(Cr+si) was under $11.7\%$, preferred orientation is defined at CrN(220), CrN(311) and $Cr_2N(111).$ The results of potentiodynamic polarization tests showed that the corrosion current density and porosity decreased with increasing Si/(Cr+si) ratio. EIS measurements showed that the corrosion resistance of Si-bearing CrN was improved by phase transformation of the film, which leads to increase of pore resistance and charge transfer resistance. At the Si(Cr+si) ratio of 20, the Si-bearing CrN possesses the best corrosion resistance due to the highest pore resistance and charge transfer resistance.