• Proceedings of the SAREK Conference
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• 2005.11a
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• pp.135-140
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• 2005

Installation of ceiling type unit is achieved by one of efforts for agreeable classroom environment embodiment along with economic growth. But research about changing the position of ceiling type unit is lacking in present. Therefore, this thesis is to study the thermal environment of 5 different position cases of ceiling type, namely Case A, B, C, D, E. Here, Case C is the case that has the position of ceiling type center of the classroom and the other 4 alternatives are 0.7 m away from the Case C according to x and z axis. In this thesis temperature distributions, air current distribution, heat amenities such as PMV of occupants are analyzed as the environmental factors. Through these factors, Case C and Case D are the better position alternatives than the alternatives of Case A, Case B and Case E because the latter cases the air current reaches directly to indoor occupants so that occupants feel chilly. This thesis has a conclusion under the condition of only one inlet air temperature and seat arrangement. But afterwards more inlet air condition and seat arrangement must be considered.

• KIEAE Journal
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• v.13 no.3
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• pp.61-69
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• 2013

The experiment on thermal characteristics of on-dol systems were carried out to apply to New Han-ok's heating system. Change of surface temperature varied with heating times, distribution of surface temperature, radiation property were surveid on four on-dol system in laboratory conditions. Followings are results. 1) "Hwang-to unit" was most favorable condition of the distribution of floor surface temperature. And the results from reaching time to thermal comfort temperature of on-dol system showed that "Hwang-to unit" was the most favorable to continuance of floor temperature. 2) There were a little difference in surface floor radiations of $30^{\circ}C$ for three wet on dol-systems. 3) It was suggested that "Hwang-to unit" is the most appropriate to floor heating system of new han-ok considering eco-friendship and continuance of floor temperature in intermittent heating condition.

• Journal of Korean Living Environment System
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• v.24 no.1
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• pp.95-106
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• 2017

The purpose of this study was to evaluate comfort functions while wearing firefighters' protective gloves in dry and wet conditions at $70^{\circ}C$ air temperature with radiant heat. Four types of firefighting gloves from Korea, Germany, United States, and Japan were evaluated in both dry and wet conditions by eight male firefighters. Firefighters put their hands and forearms wearing gloves into a hands-radiant chamber that maintained at an air temperature of $70{\pm}2^{\circ}C$ ($T_a$) and globe temperature $106^{\circ}C$ ($T_g$). During the exposure, subjects followed a fixed protocol of manual movements and stopped the exposure when they felt being intolerable. Results showed that completion time was extended by 6 min on average when gloves got wet and 15 min for the Japanese gloves was extended when compared to its dry condition (p<.001); microclimate humidity on the palm at the last stage was greater for wet conditions than dry conditions in the all gloves; and skin temperatures on mid-fingertip, palm, and hand were significantly lower for wet conditions than dry conditions especially for Japanese gloves (p<.001). These results indicate that the exposure time without thermal pain to radiant heat could be extended by wetting gloves during the low radiant heat exposure.

• Proceedings of the SAREK Conference
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• 2008.06a
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• pp.976-980
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• 2008

Ventilation equipment performs a cental role to maintain comfort subway environment. So ventilation equipment of Busan subway first line is needed to improvement thermal environment. In this study, condition of thermal environment is presented to improve ventilation equipment at existing subway station platforms by measuring thermal environment of platforms operated ventilation equipment at 14 stations of Busan subway first line. AWS of data in comparison with the neighbouring platforms and thermal environment analysis.

• 한국태양에너지학회:학술대회논문집
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• 2009.04a
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• pp.263-268
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• 2009

The current focus of domestic car industry is moving from technological development to reducing greenhouse gas. This study investigates and measures the HVAC system and indoor air condition of highway buses, which is conducted to develop a HVAC system using natural energy in the future. The measurements show that thermal balance is not fulfilled because heating sources are randomly placed, and relative humidity is in the 20 percent range both in HVAC and non-HVAC systems, which is far below 40%, or the highest thermal comfort level. CO2 concentration was found to be an average of 1500 ppm, but not more than 2522 ppm with 15 persons on board, and with 29 persons on board, an average of 2053 ppm, but not more than 3066 ppm, both of which far exceed allowed CO2 concentration level, or 1000 ppm. Generally, highway buses drop by rest stops and open doors for 15 to 20 minutes for getting in fresh air. But its air improvement effect is temporary, and it exacerbates indoor air condition.

• Fashion & Textile Research Journal
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• v.24 no.5
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• pp.655-665
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• 2022

This study evaluated the validity of a newly developed mobility protocol examining the comfort functions and requirements of personal protective equipment (PPE) for COVID-19 healthcare workers. Eight males (age: 24.7 ± 3.0 y, height: 173.4 ± 2.3 cm, and body weight 69.9 ± 3.7 kg) participated in the following three PPE conditions: (1) Plastic gown ensemble, (2) Level D ensemble, and (3) Powered air purifying respirator (PAPR) ensemble. The mobility protocol consisted of 10 different tasks in addition to donning and doffing. The 10 tasks were repeated twice at an air temperature of 25oC with 74% RH. The results showed significant differences among the three PPE conditions in mean skin temperature, local skin temperatures (the forehead, thigh, calf, and foot), clothing microclimate (the chest and back), thermal sensation, thermal comfort, and humidity sensation, while there were no significant differences in heart rate or total sweat rate. At rest, the subjects felt less warm and more comfortable in the PAPR than in the Level D condition (P<0.05). However, subjective perceptions in the PAPR and Level D conditions became similar as the tasks progressed and mean skin and leg temperature became greater for the PAPR than the Level D condition (P<0.05). An interview was conducted just after completing the mobility test protocol, and suggestions for improving each PPE item were obtained. To sum up, the mobility test protocol was valid for evaluating the comfort functions of PPE for healthcare workers and obtaining requirements for improving the mobility of each PPE item.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.17 no.5
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• pp.397-403
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• 2005

The thermal comfort of occupants is directly related to several environmental factors such as velocity of air flow, turbulence intensity and temperature distribution of indoor air. The purpose of this study is to evaluate the indoor air flow and temperature distribution in office area using under-floor air-conditioning system (UFAC System) based on the results from physical measurements and to perform a Computer Fluid Dynamics (CFD) under the same condition of inlet and outlet as field measurement. The results from the CFD simulation are similar to those from the field measurement. The results show that UFAC system is provide proper indoor condition for occupants.

• Fashion & Textile Research Journal
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• v.10 no.5
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• pp.683-689
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• 2008

The purpose of this study was to investigate physiological responses such as rectal temperature, skin temperature, micro climate, sweat rate and subjective sensations using cold protective clothing with five different clo value. The clo value was measured by thermal manikin in windless condition. Healthy five 20's males volunteered as subjects for wearing trial experiment. The climate chamber was controlled at $50^{\circ}C$, 65% RH. The experiment consisted of repeated exercise and recovery periods. We found that the higher clo value has, the higher mean skin temperature, micro climate and sweat rate show. They felt warm and wet with higher insulation clothing. Thermal comfort increased in the last recovery period after exercise. There was significant difference between five cold protective clothing. In correlation analysis of clo value, it showed that correlation coefficient(r) values were more than 0.8. Therefore, in terms of clothing insulation, we found that correlation between thermal manikin experiment and wearing trial experiment was high. Clothing insulation could be variable according to many factors such as body movement, covering area, clothing gap, layering and design. Considering the body movement, we thought that insulation measurement need to carry out both thermal manikin experiment and wearing trial experiment.

• Fashion & Textile Research Journal
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• v.13 no.6
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• pp.959-965
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• 2011

The purpose of this study was to evaluate the effect of wearing induced micro current brassiere on the physiological responses of women. Four women participated to wear a different brassiere condition: with and without micro current chips. Subjects were carried out after wearing the induced micro current brassiere for 120minutes. Eardrum temperature, skin temperature, blood pressure, heart rate, thermal perception, humid perception, and comfort perception were obtained. The results were as follows. The brassiere with micro current chips showed better performance on weight loss than the brassiere without micro current chips. Participants in a higher level of BMI were more likely to lose greater weight. Mean skin temperatures decreased with micro current chips. Participants felt more comfortable for walking in micro current brassiere than in brassiere without micro current chips.

• Journal of the Korean Society of Clothing and Textiles
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• v.28 no.8
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• pp.1175-1185
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• 2004

This study evaluated thermo-physiological and subjective properties of improved disposable coveralls for railroad carriage maintenance through climatic chamber trials and a filed study. Subjects wore five kinds of disposable coveralls (Type A: a disposable coverall on the market, Type B: a coverall with an improved hood and size-adjustable design, Type C: a coverall with a portable hood, Type D: a coverall with small holes for ventilation, Type E: a sleeveless coverall, Type F: a separated type of coverall with half sleeves) The air temperature in the climatic chamber was set in 9$^{\circ}C$ and 30$^{\circ}C$ For each condition, subjects simulated the railroad work for 120min. and rectal temperature, skin temperatures, clothing microclimate and subjective sensations were measured. The results of chamber trials showed rectal temperature and clothing microclimate did not display significant differences by clothing type. In 30$^{\circ}C$ air temperature, mean skin temperature was higher in Type E and Type F than in Type A(p＜0.05) but between the improved coveralls(B-F), we could not find any significant difference. In the case of thermal comfort, the most preferred types were Type B and Type C in 9$^{\circ}C$ and Type F in 30$^{\circ}C$. All subjects felt more comfortable in the improved coveralls than in coveralls of the market (Type A). In field study, workers preferred Type B, Type C and Type F to Type A but the most favorite type differed by the specific type of work. Especially, workers were dissatisfied that Type D tore easily due to lots of small holes around the armpits and Type I did not protect workers＇ shoulder and arms from oil contamination. According to the climatic chamber trials and field study, the most effective coveralls were Type B and Type C for winter and Type F for summer.