• Journal of the Korean Society of Safety
• /
• v.16 no.1
• /
• pp.37-42
• /
• 2001

The severity of electric shock is entirely dependent on body resistance. When the human body becomes a part of electric circuit, the body resistance is given as a function of shock scenario. Factors which consist of applied voltage, shock duration, body current path and contact area, etc.. The body resistance is defined as the voltage applied to subjects divided by the body current. To secure safety of the subjects, the experiment is conducted on 10 subjects, the body current is limited to 4mA. And only three factors under many shock scenario conditions are used to determine the body resistance. The three factors are the applied voltage, the current pathway and the contact area. The object of this work is to estimate the dynamic resistance of the human body as a function of applied voltage using the body current at low-voltage levels. The data of the body current at low-voltage levels are extrapolated to high-voltage levels using two analytic functions with specified constants calculated by numerical method. Also we can provide permissible body voltage for various copper electrodes on the basis of the data determined with the dynamic resistance and the body current.

• Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
• /
• v.27 no.9
• /
• pp.90-99
• /
• 2013

To analyze the effectiveness of the resistive leakage current monitoring as a technology preventing electrical accidents, in this paper, we have estimated the phase of the body impedance by using the body impedance model and the body impedance data from IEC. We also have analyzed the phase of the electric body current in the case of 60Hz/220V. From these results, we concluded that deliberate researches about the phase of the electrical body current and related regulations must be carried out before the resistive leakage current monitoring unit is used to protect electric shock. And we concluded that the resistive leakage current monitoring unit can be utilized to prevent electrical fires caused by electric leakage current without unwanted circuit break due to capacitive leakage current flowing from line filter capacitors to the earth.

• Journal of the Korean Society of Safety
• /
• v.16 no.3
• /
• pp.53-60
• /
• 2001

This paper presents a graphical method for hazard assessment of electric shock by safety criteria. For the human body to be safety actual body current should not exceed safety criteria, i.e. allowable body current. The assessment method presented in this paper is based m the safety criteria of the IEEE Standard 80 as well as the IEC 479-1. The hazard can be assessed in terms of alterable touch voltages instead of alterable body current. Thus, the hazard assessment of given electric shock condition is referred to a procedure by which the actual touch voltages are compared with the allowable (safe) touch voltages. Since the IEC 479-1 safety criteria are nonlinear, the graphical method is presented for the hazard assessment. Body current and body voltage are calculated with the allowable touch voltage. A comparison of the safety criteria of two widely accepted standards, i.e. the IEEE Std 80 End the IEC 479-1 is proposed. Also Thevenin equivalent resistance is obtained from electric shock model expressed by two-port earth-grid-foot system. On the basis of calculated results, the allowable touch voltage, the body current and the body voltage we can conduct the hazard or safety assessment and estimate the severity of electric shock.

• Ocean Systems Engineering
• /
• v.7 no.2
• /
• pp.121-141
• /
• 2017

The purpose of this paper is to understand and model the slow current (~2 m/s) effects on the global response of a floating offshore platform in waves. A time-domain numerical simulation of full wave-current-body interaction by a quadratic boundary element method (QBEM) is applied to compute the hydrodynamic loads and motions of a floating body under the combined influence of waves and current. The study is performed in the context of linearized potential flow theory that is sufficient in understanding the leading-order current effect on the body motion. The numerical simulations are validated by quantitative comparisons of the hydrodynamic coefficients with the WAMIT prediction for a truncated vertical circular cylinder in the absence of current. It is found from the simulation results that the presence of current leads to a loss of symmetry in flow dynamics for a tension-leg platform (TLP) with symmetric geometry, resulting in the coupling of the heave motion with the surge and pitch motions. Moreover, the presence of current largely affects the wave excitation force and moment as well as the motion of the platform while it has a negligible influence on the added mass and damping coefficients. It is also found that the current effect is strongly correlated with the wavelength but not frequency of the wave field. The global motion of a floating body in the presence of a slow current at relatively small encounter wave frequencies can be satisfactorily approximated by the response of the body in the absence of current at the intrinsic frequency corresponding to the same wavelength as in the presence of current. This finding has a significant implication in the model test of global motions of offshore structures in ocean waves and currents.

• Korean Journal of Community Nutrition
• /
• v.2 no.2
• /
• pp.197-205
• /
• 1997

This study was conducted to investigate adolescents' body size and their concerns and perceptions about body image. Group means of heights and weights were 171.5cm and 60.3kg for boys and 159.3cm and 52.3Kg for girls. Body Mass Index(BMI) of the subjects were 20.5 for boys and 20.6 for girls. Only 11.5$\%$ of subjects were overweight or obese, however 42.5% of subjects had experienced weight control, and the main reason for weight control was to lose weight(80.6$\%$). In concern for body image and frequency of eating distrubance ; females had more concern than males, the group who had attempted weight control had more concern than those who had not, and the group who were overweight had more concern than those who were under and normal weight. In perception about body image, using a set of nine figure drawings arranged from very thin to very heavy figures, subjects rated their current figure, considered figure(how they appeared to others), ideal figure, and attractive figure. For boys, the current, ideal, and most attractive figures were almost identical, but for girls, the ideal figure was significantly thinner than current figure and attractive figure was significantly thinner than current figure. The greater the preference for thinner figure as idal and attractive figure, the higher the concern for body image and frequency of eating distrubance. Thus it seems that a distorted perception of ideal body size affects adolescents' concern for body image and eating behaviors.

• 전기의세계
• /
• v.29 no.1
• /
• pp.21-27
• /
• 1980

The effect of electric shock on human body is enormousness, which leads to warmth, tingling, and even death. The mean values of perception currents obtained on 91 men and 39 women are about 0.77(mA) for men and 0.57(mA) for women. The mean value for women is approximately seven tenths that of men. An individual can tolerate, with no adverse effects, repeated exposure to the reactions associated with currents of his let-go level, and the mean value of let-go currents obtained from 27 normal men is 6.29(mA). Lethal currents flowing human body is very dangerous even for a short time. So, it is necessary to have recourse to animal experiments ot determine lethal current for human. An analysis of experimental data indicates that body weight and shock duration are important factors in determining the lethal current. It is suggested that the relationship between current and shock duration is given by I=K/.root.T, and lethal current is proportional to body weight, where I is the current in milliampere, and T is the time in seconds.

• The Transactions of the Korean Institute of Electrical Engineers A
• /
• v.53 no.8
• /
• pp.461-465
• /
• 2004

This paper analysed the induced current density by electric field of human body under the 765 kV transmission line considering permittivity and conductivity. As permittivity of human body is very high as $10^6$ at 60 Hz, special numerical computation technique in Surface Charge Method(SCM) for composite media with extremely different properties is applied to reduce calculation error of induced current density and electric field inside the human body. Calculation results show that the average of the induced current density inside human body is about 3mA/$m^2$, which is less than ICNIRP criterion (10mA/$m^2$).

• ETRI Journal
• /
• v.17 no.4
• /
• pp.1-12
• /
• 1996

A novel body-tied silicon-on-insulator(SOI) n-channel metal-oxide-semiconductor field-effect transistor with grounded body electrode named GBSOI nMOSFET has been developed by wafer bonding and etch-back technology. It has no floating body effect such as kink phenomena on the drain current curves, single-transistor latch and drain current overshoot inherent in a normal SOI device with floating body. We have characterized the interface trap density, kink phenomena on the drain current ($I_{DS}-V_{DS}$) curves, substrate resistance effect on the $I_{DS}-V_{DS}$ curves, subthreshold current characteristics and single transistor latch of these transistors. We have confirmed that the GBSOI structure is suitable for high-speed and low-voltage VLSI circuits.

• Proceedings of the Korean Society of Machine Tool Engineers Conference
• /
• 2000.04a
• /
• pp.66-72
• /
• 2000

Commercial eddy current dynamometers control the torque of ratating body (poer supply machine) with the field coil current being operated as a braking force. In this paper, we studied about the relation between the field coil current and the torque load of eddy current dynamometer. By the torque measuring analysis of eddy current dynamometer, it is linear relation between the brake force measured from the torque meter (e.g. load cell, strain gage or spring balance etc.) which is installed at the case of dynamometer and the multiply of shaft rpm by the square of field coil current (N$\times$Ia2). To prove the relation, it was experimented and showed that the torque operated by the rotating body can be measured with the shaft rpm and the field coil current of eddy current dynamometer. This result shows a possibility that eddy current dynamometer can measures the torque of rotating body without special torque measuring devices.

• Korean Journal of Community Nutrition
• /
• v.10 no.6
• /
• pp.930-942
• /
• 2005

This study was performed to investigate body image perceptions of women about themselves and their preschool children and also to investigate the relationship between these perceptions. Subjects were 545 women and their children (279 boys and 268 girls) residing in Daejeon city. $67.7\%$ of women were classified as normal group, $18.6\%$ as overweight group, and $13.8\%$ as underweight group by BMI. $68.5\%\;and\;78.7\%$ of their boys and girls, respectively, were classified as normal group, $22.4\%\;and\;16.4\%$ as overweight group, $9.1\%\;and\;4.9\%$ as underweight group by WLI. Women made relatively accurate judgments on their current body sizes and selected their body images as the most desirable one. But they preferred plumper figures for their children and failed to perceive their overweight children as overweight. While $74.7\%$ of women wished to be thinner, $81.1\%$ of them wished their children to be fatter. Women spending less then 100 thousand won and more than 500 thousand won as monthly food expenses and having only one child perceived their children's current body sizes the lowest and the highest, respectively. Women wished boys to be fatter than girls. Their current body sizes were correlated positively with the children's current body size (p < .01), and their healthiest, attractive, and 'wish' figures were correlated positively with children's current, healthiest, attractive, and 'wish' figures (p < .05- p < .01). Body size dissatisfaction (wish to be thinner) and BMI of women were correlated negatively with children's healthiest and attractive figures (p < .01). These findings suggest that in order to correct the women's body image misperceptions and to prevent childhood obesity, mother's perception about healthy body images for themselves and their children need to be included in nutrition education. Also, it is necessary to assist mothers to understand the relationship of body size and weight status with the risk of chronic disease which might appear later in their children's life. (Korean J Community Nutrition 10(6) : $930\∼942$, 2005)