• 한국의류학회지
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• 제22권7호
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• pp.963-968
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• 1998

A study was conducted to investigate the effect of cooling hands of feet on human thermoregulation in the cold. Eight young (22$\pm$1 yr) and eight aged (69$\pm$4 yr) men volun-teered as subjects They stayed at 1$0^{\circ}C$ in the supine posture during the experiment which included hands or feet exposure to the air for 20 minutes. Hand Exposure (HE) and Foot Exposure (FE) were conducted in radomized order and the baseline was kept before HE and FE. Core temperatures, limb skin temperatures adn thermal sensations were measured. Obtained data were analyze using t-test and correlation. Rectal and esophageal tem-peratures increased in the young (YG) and in aged (AG). Change rate of esophageal temperature (Tes) was maintained higher during FE than HE while rectal temperature showed no differences between YG and AG, and between HE and FE. Hand and foot skintemperature in YG and AG decreased similarly during HE and Fe. Forearm skin temperature during HE decreased while leg skin temperature during FE showed no change HE and Fe. It was concluded that the lower cooling. Furthermore, the increase of Tes was greater in young men than aged men. It is also suggested that the wearing behavior can be differently modified between young and aged men.

• Journal of Radiation Protection and Research
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• 제35권3호
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• pp.99-104
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• 2010

The potential ability of environmental temperature to enhance the effect of microwave radiation (7 GHz) was experimentally studied for rabbit heating after simultaneous application of both agents. The tested ambient temperatures (30 and $38^{\circ}C$) didn't exert a considerable influence upon rabbit heat homeostasis after the used duration of exposure (3 hours and 15 minutes, correspondingly). The synergistic interaction of microwave irradiation and ambient temperature was demonstrated for rabbit heating. Power flux density of microwave irradiation was shown to be a determinant of the synergistic interaction effectiveness. For the fixed ambient temperature ($30^{\circ}C$), the synergism was shown to be observed only within a definite power flux density ($0-100\;mW{\cdot}cm^{-2}$), inside of which there was an optimal intensity ($20\;mW{\cdot}cm^{-2}$), which maximized the synergistic effect. Any deviation of the power flux density from the optimal value resulted in a reduction of the synergy. It is concluded that any assessment of the health or environmental risks should take into account the synergistic interaction between ambient temperature and microwave radiation.

• Asian-Australasian Journal of Animal Sciences
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• 제7권2호
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• pp.179-182
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• 1994

A study was conducted using four dairy heifers to determine the effect of 10, 20 and $30^{\circ}C$ environmental temperatures on the physiological responses and heat production, at a fixed level of TDN intake ($60.5\;g/kg^{0.75}\;d$). The analysis showed significant affects of environmental temperature on respiration rate (RR), mean body temperature (Tb), changes in body heat storage (S) and heat production (HP). The HP at $20^{\circ}C$ was almost the same as at $10^{\circ}C$, but the HP at $30^{\circ}C$ was 11% higher than at $10^{\circ}C$. A tendency for an elongation of standing time (ST) with the increase in environmental temperature was also observed. These results suggest that the increase in energy cost of elongation of ST ($9.2\;kJ/kg^{0.75}\;d$) and $1.3^{\circ}C$ increase in Tb ($17.3\;kJ/kg^{0.75}\;d$).

• Asian-Australasian Journal of Animal Sciences
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• 제10권1호
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• pp.64-69
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• 1997

A study was conducted on the effects of ploughing on physiological responses of male and female Bali-cattle. A $2{\times}2{\times}6{\times}8$ factorial design (2 seasons, 2 sexes, 6 days and 8 consecutive time of measurements every 30 minutes) was employed. Responses during the cool/humid season were lower than hot/dry; respiration rate (RR) was 52 vs 75/min, rectal temperature(RT) was 39.1 vs $39.5^{\circ}C$ and skin temperature (ST) was 37.1 vs $37.6^{\circ}C$. Within sexes, males were less tolerant than females in that their RR (66 vs 61 breath/min), RT (39.4 vs $39.2^{\circ}C$) and ST (37.6 vs $37.1^{\circ}C$) were each higher than females during work. With increasing time, during the average 2.5 h working period gradual increases in RR, RT and ST were recorded and the overall increases of 84 breath/min, $1.9^{\circ}C$ and $13.8^{\circ}C$ respectively (p < 0.001). Packed cell volume (PCV) data indicated significant difference between sexes, time and season (p < 0.001, p < 0.05 and p < 0.001 respectively). Within time (before and after 2.5 h working) the PCV decreased from 27.4 to 25.6%.

• 한국의류학회지
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• 제25권2호
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• pp.339-349
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• 2001

This study was investigated the effects of ambient temperatures and menstrual cycle on Resting Metabolic Rate(RMR), Rectal Temperature(Tre), Skin(forehead, chest, abdomen, forearm, hand, thigh, leg, foot) Temperatures, and subjective thermal sensations in 8 young Korean females(ages 22-25, voluntarily). The Tre and the Skin Temperatures were measured in once every five minute for one hour. RMR was measured three times at 30 minutes intervals by indirect calorimetry. All measurements were gathered during Luteal Phase(LP), Menstruation(M), and Follicular Phase(FP) at two levels of ambient temperatures; low(17~21$^{\circ}C$) and middle(21.1~$25^{\circ}C$). LP were the highest values during FP and M in RMR, Tre, forehead temperature, chest temperature and abdomen temperature, while the leg(leg and foot) and arm(forearm and hand) temperatures were higher during FP rather than during LP at each ambient temperature. The downward curve of Tre in the experiment was larger during FP than LP. The values in subjective thermal sensations were most comfortable during LP than M and FP at each ambient temperature. The LP-FP differences in core and mean skin temperatures, and resting metabolic rate, were more significant at middle ambient temperatures than at low ambient temperatures.

• 한국의류학회지
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• 제35권7호
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• pp.713-720
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• 2011

This study investigated the effect of cold acclimatization training on body composition including weight, fat mass, and muscle mass with 10 subjects (5 males and 5 females). During the 3-week acclimatization training program, they visited an artificial climate chamber ($15^{\circ}C$) 15 times and were exposed to cold environment with light clothing for 2 hours. Body composition was measured before and after cold training using bioelectric impedance analysis that was later compared by a paired t-test. In the process of thermoregulation, muscle contraction was accompanied by increased substrate metabolism for rising heat production. After cold training, the muscle mass increased and fat mass decreased significantly (p<.1, p<.05), subsequently the body composition changed. It was found that cold acclimatization training could be used as a treatment for obesity. It was suggested that further investigation on the long term effects of mild cold exposure using clothing and its potential applicability as an obesity treatment.

• 한국동물학회지
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• 제18권4호
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• pp.173-180
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• 1975

Sprague-Dawley 系인 成熟한 雄性흰쥐를 對照群과 實驗群으로 나누어 對照群은 $23^\\circ C$에서 保存하였으며 實驗群은 $30^\\circ C 및 33^\\circ C$에서 各各 240時間 및 64時間동안 繼續하여 溫度順應시켰다. 溫熱順應의 各 時間區마다 血淸알칼리性 및 酸性 Phosphatase의 活性을 測定하였다. $30^\\circ C$에서는 上記 酵素活性의 變化相은 $33^\\circ C$에 比하여 一般的으로 顯著하였다. 다시 말하면 $30^\\circ C$에서의 溫熱順應에 있어서 血淸알칼리性 및 酸性 Phosphatase는 對照群에 比하여 一般的으로 높은 活性의 恒定特續性을 나타내었다. 以上의 結果로 미루어 보아 上記 酵素는 $30^\\circ C$의 溫熱順應에 있어서 生化學的으로 直接 또는 間接으로 溫度調節에 關與하고 있는 것으로 思料된다.

• 수면정신생리
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• 제5권1호
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• pp.1-11
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• 1998

Chronobiology is the area of medicine that is, how time-related event shape our daily biologic responses and apply to any aspect of medicine with regard to altering pathophysiology and treatment response. In mammals, there are several evidences that prove suprachiasmatic nuclei(SCN) is the major circadian pacemaker and the circadian rhythm influences so many biological aspects of an living organism such as rest-activity, thermoregulation, reproduction, and endocrine system. In case of human beings, there had been little information of circadian system. That may be due to the experimental, technical difficulties to study but also to the fact that human has the more complex environments that may alter the circadina rhythm like the artificial light, many socio-cultural aspects and so forth. However, several reports of these days indicate human's circadian system is composed of two or more circadian oscillators and SCN is the major circadian oscillator among them like the other mammals. Free-running circadinan period of mankind is about 24 hours rather than about 25 hours, and rest-activity rhythm is polymodal like other species. In addition to that, human may have capcities to change the circadian rhythm as the seasonal changes of daynight schedule. In this article, the author will summarize recent progress of anatomy and physiology of the circadian clock mechanism in humans.

• 감성과학
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• 제20권4호
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• pp.135-142
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• 2017

In the present study, we investigated the physiological effects of smartphone use at night when the display luminance and white balance were differently manipulated. Two levels of luminance and two types of white balance were combined to form four types of displays. Subjects were instructed to use smartphones between 23:00 to 01:00 twice a week for two weeks, and for each trial, subjects were given one of the four display types. Melatonin concentration in the saliva, body temperature and heart rate were measured before and after each experiment. The experimental result showed that the low luminance display supported melatonin secretion and thermoregulation compared to the high luminance display. With regard to the white balance, higher melatonin level was observed when using the display that filtered blue light. The low luminance display together with yellowish tint best supported restful sleep at night in terms of every physiological response. This study collectively demonstrates that bright and blue light emitted from smartphone displays adversely affect melatonin secretion, body temperature, and heart rate, and therefore, suggests the use of a display with low luminance or a display that filters blue light for a restful sleep at night.

• 한국의류학회지
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• 제25권10호
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• pp.1745-1753
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• 2001

본 연구는 한랭 환경 하에서의 인체의 국소 가온 자극이 생리, 감각반응에 끼치는 영향을 검토했다. 건강한 성인여자 7명을 대상으로, 기온 $25^{\circ}C$, 습도50%의 환경 하에서 균일한 국소 가온을 부하 했을 때 피부온, 고막온, 손가락, 발가락 혈류량, 온냉감, 쾌적감의 반응에 미치는 영향을 검토한 결과는 다음과 같다. 1) 국소가온에 의해 가온 부위 피부온은 유의하게 상승하고 가온 부위에 따라 상승도에는 유의한 차가 보였다. 2) 국소가온에 의해 고막온은 머리의 가온 시에 높은 상승, 전완의 가온 시에 상승하고, 다른 가온 부위에서는 하강의 경향이 보였다. 3) 국소가온에 의해 혈류량의 변화는 3개의 군으로 분류된다. 가온과 함께 손가락 혈류량이 증가하는 군, 발가락 혈류량이 변화하는 군, 양쪽의 혈류량이 적게 변화하는 군으로 나누어진다. 이것을 각 피험자의 평균 피부온 수준 즉 체온조절 수준과 관계 있는 것으로 논할 수 있다 4)국소 가온에 의해 각 부 위 피부온으로의 파급효과는 머리, 상완의 가온 시에 크지만 대퇴, 하퇴 다리의 가온 시에는 대부분의 부위에서 영향이 보이지는 않았다. 5) 이와 같이 국소 가온에 의 한 생리, 감각반응은 가온 부위에 따라 다르고 머리, 상완의 가온 시에는 생리반응이 크고 하퇴, 다리의 가온시에는 국소의 감각변화가 컸다.