• Journal of the Korean Society of Industry Convergence
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• v.1 no.1
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• pp.21-30
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• 1998

The purpose of this study is to clarify the floor temperature on the human body and to estimate thermal comfort zone in a heated room. In order to evaluate the effects of floor heating, a series of experiments were carried out using Korean subjects. The following experiments were conducted: 1) to obtain the effective radiation area and configuration factors of the person in the sitting posture on a floor to get the mean radiant temperature, 2) to measure contacted area of the person to the floor to calculate conduction heat rate, 3) to measure convective heat transfer coefficient of the body and 4) to know the thermal comfort zone of indoor environment heated by ON-DOL. Subjects were exposed to the following conditions: combinations of air temperature $20^{\circ}C$, $22.5^{\circ}C$, $25^{\circ}C$, and floor temperature $20^{\circ}C$, $22.5^{\circ}C$, $25^{\circ}C$, $27.5^{\circ}C$, $30^{\circ}C$, $32.5^{\circ}C$, $35^{\circ}C$, $37.5^{\circ}C$, $40^{\circ}C$ under still air and 50% relative humidity in the controllable artificial climate chamber. To evaluate the effect of heat conduction between the body and a floor modified mean skin temperature was defined. Weighting coefficient to calculate mean skin temperature were modified with the contacted area. The experiments revealed a positive correlation between the modified operative temperature and the modified mean skin temperature. The modified mean skin temperature can indicate the effect of heat conduction between body and a floor surface.

• Transactions of the Korean Society of Automotive Engineers
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• v.10 no.4
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• pp.158-165
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• 2002

This Paper deals with the headlamp lens surface temperature distribution of p/c headlamp using the three categories of H4 halogen bulbs. Glass is gradually replaced by P/C for the lens material off vehicle headlamp due to the weight reduction and stream lined body of a vehicle. With this trend, the newly established standards for a headlamp with a P/C lens in Europe requires that the heat generated by a bulb should not distort the lens surface. Also the requirements fur the bulb of a headlamp are being enforced in U.S.A & Europe. However, such requirements are not established yet in Korea. By using three kinds (60/55w, 100/90w, 130/90w) of H4 halogen bulbs in this experiment, the surface temperature distribution and Max. temperature on the lens were measured. The results of this study implies the necessity of requirement fur the bulb off headlamp.

• Journal of the Korean Burn Society
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• v.21 no.1
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• pp.17-21
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• 2018

Purpose: This study aimed to evaluate the thermal protective function of firefighter clothes and gloves through real scale fire simulations. Methods: Firstly, the fire simulation by real scale flame was performed for firefighter clothes. A manikin equipped with firefighter clothes was directly exposed to flames which energy average is 84 Kw/m². for 22 seconds. Heat flux gauges attached on the body measured surface temperature elevation. Secondly, we also performed the other fire simulation by hot plate exposure to firefighter gloves. Firefighter gloves with heat flux gauges exposed hot plate which temperature is 300℃ in both dry and moist conditions. Primary outcome was surface temperature change of manikin body (first simulation) and hand (second simulation) over times. Results: In the first flame simulation, the surface temperature of face and shoulders elevated more rapidly comparing with the other body surface area when initial period of flame shutter open. After 18sec of shutter open, the surface temperature of upper trunk elevated rapildy. After shutter closure, high surface temperature kept continuously on right side of face and left shoulder. In the second hot plate simulation, fingers and palms showed higher surface temperature than the other areas of hands in the both dry and wet conditions. Conclusion: This study suggests that the real scale flame enables firefighter clothes to lose their heat protective function suddenly after 18 seconds. Additionally, the protective function of firefighter gloves were relatively weaker in the palmar side of fingers than the other parts of hand. There should be additional study for evaluate thermal protection performance of firefighter clothes. And, further effort for reinforce palmar side of fingers of firefighter gloves should be done.

• Korean Journal of Human Ecology
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• v.15 no.4
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• pp.647-650
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• 2006

The factors affecting clothing comfort are temperature, humidity, and air velocity of clothing microclimate which is the temperature and the humidity between the skin surface and the innermost garment, clothing pressure and clothing texture to the skin. This study was designed to estimate the distribution of clothing microclimate on the upper body. All the data of this study were collected from volunteered male subjects in the controlled climate chamber laboratory in which the temperature was $25\pm1^{\circ}C$, the relative humidity $50\pm5%$, and the air velocity 30cm/sec. All subjects should wear long-sleeved inner wear and pants woven in 100% cotton. Clothing microclimate temperature at 16 sites on the chest and 16 sites on the back was measured. The results were as follows: the distribution of the clothing microclimate temperature on the upper body was $30.6\sim34.7^{\circ}C$ on the breast and $31.5\sim35.4^{\circ}C$ on the back. While a mean temperature on the chest was 33.3$^{\circ}C$, it was 33.1$^{\circ}C$ on the back.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.151-157
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• 2002

This study examined the changes in body temperature through conductive heat applied to the body and clarified the influences of body fluid on the thermal effects. Body fluid was measured using the Segmental Bioelectrical Impedance Analysis method. The subjects consisted of 13 men and 14 women. TBW was 37.56 (4.35 L for men and 29.93 (3.12 L for women, with the former being significantly (p<0.01) higher. The amount of body fluid in the right and left legs was 6.46 (0.83 L and 6.39 (0.86 L for men and 4.78 (0.49 L and 4.78 (0.49 L for women, respectively, with men's values being significantly (p<0.01) higher than women's on both the right and left sides. The maximal change in the surface temperature was 33.93 (0.61(C at the start of a warm bath to 3407 (0.61(C after 14 min for men. In contrast, the maximal change was 33.38 (0.99(C at the start to 33.73 (0.86(C after 18 min for women. For the other sites, the maximal temperature in Depths 1 and 2 was attained earlier for men than for women. The decrease in body temperature after the end of warming was more remarkable for men. Men had fluid with a higher conductivity than women, indicating influences of body fluid on the changes in body temperature. There were few changes in body composition with a partial bath having a crossed effect, indicating that this is a safe therapeutic method for elderly people.

• Journal of the Korean Society of Clothing and Textiles
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• v.48 no.3
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• pp.501-510
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• 2024

This study aimed to compare the cooling effect of specific body parts to increase workers' thermal comfort. The parts to be cooled comprised the head and neck; the coolant was a phase change material. The participants were ten men in their 20s of average size according to the 8th Size Korea. The experiment was conducted under the following conditions: 28.0 ± 0.5℃, 60.0 ± 5.0% RH, and 0.2 ± 0.1m/s. The exercise consisted of participants moving for 15 min at a constant speed of 80 BPM; later, a subjective sensation was performed, and the clothing surface temperature was measured. In doing so, heat, wetness, and discomfort after exercise were confirmed to have increased without a coolant. Significant differences over time appeared only when no coolant was used, showing that thermal comfort decreased. Despite the addition of coolant, the clothing surface temperature gradually increased over time, but it decreased with coolant rather than without it. Therefore, additional coolant areas, a lower temperature, and simultaneous cooling convection were required to improve thermal comfort.

• Journal of the Korean Mathematical Society
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• v.44 no.6
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• pp.1397-1415
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• 2007

We consider an inverse heat conduction problem(IHCP) in a quarter plane which appears in some applied subjects. We want to determine the heat flux on the surface of a body from a measured temperature history at a fixed location inside the body. This is a severely ill-posed problem in the sense that arbitrarily "small" differences in the input temperature data may lead to arbitrarily "large" differences in the surface flux. A semi-discrete central difference scheme in time is employed to deal with the ill posed problem. We obtain some error estimates which also give the information about how to choose the step length in time. Some numerical examples illustrate the effects of the proposed method.

• Progress in Superconductivity and Cryogenics
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• v.15 no.3
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• pp.20-23
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• 2013

In the development of high temperature superconducting (HTS) power machines, HTS bushing is one of core technologies. In particular, the insulation body with sheds and electrical insulation at cryogenic temperature have attracted a great deal of interest from the view point of the size, weight and efficiency of bushing. In this study, the electrical and mechanical characteristics of various insulators for body in liquid nitrogen ($LN_2$) were investigated. And the surface discharge distance, collar length of GFRP sheds were studied. To emit bubbles between sheds, the shape and arrangement of shed were studied. The shed structure for 60 kV class HTS bushing were designed with regular arrangement.

• Transactions of the Korean Society of Machine Tool Engineers
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• v.17 no.6
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• pp.23-27
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• 2008

This study is to evaluate the tool life of portable beveler which have various cooling system. It was compared with 3 different bevelers which has each other cooling system. Beveler A has no cooling system, beveler B has the cooling system for only inside of body, and beveler C has the cooling system for both the cutter and inside of body. The temperature of beveler A cutter surface had been continuously increasing as processing, but the rising tendency of temperature of beveler B cutter surface has slightly changed. In case of beveler C, the temperature is maintained. The tool life of beveler C is about 105m which is around 400% of beveler A(25m), and around 130% of beveler B(80m).

• Korean Journal of Human Ecology
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• v.7 no.1
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• pp.139-146
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• 1998

The actual clothing conditions of male collegian were surveyed to analyse clothing contents and the rate of wearing underwear. Then, clothing microclimate, physiological responses, and subjective sensations were investigated through wearing trials on human body in climatic chamber based on the results from the survey. The results were follows: 1. Male collegian wore T-shirts, jeans, and socks in summer, and total clothing weight per body surface area was $561g/m^2$. The number of clothes for upper body were 1 layer, but the number of clothes for lower body were 2 layers. Subjective sensations have no significant difference with wearing underwear. 2. Most physiological responses including temperature inside clothing, mean skin temperature, skin temperature of chest, abdomen, thigh, and lower leg, and sweat rate, were higher in with-underwear than in without-underwear. But pulse rates were not significantly different between with-and without-underwear.