• 한국생활과학회지
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• 제13권5호
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• pp.777-785
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• 2004

We intend to analyze reasons for low acceptability of protective clothing in pesticide-spraying farmers in Korea, and to use the information for designing new clothing with better acceptability. To understand the attitude of farmers toward wearing protective clothing during spray, a survey was performed on 256 farmers. It is evident that the stress, which is caused by inadequate body temperature regulation, and its accompanying physiological responses are two of the leading factors for the low acceptability of protective clothing. Although the cost of clothing is not an important factor currently, low cost clothing is desirable in the future. Fancy of design is unimportant for new clothing. The results are discussed in conjunction with a desirable research focus for new types of protective clothing. Efforts should be made to ameliorate thermal stress through protective material development and garment design.

• 한국의류산업학회지
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• 제12권4호
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• pp.531-537
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• 2010

The purpose of this study was to review physiological responses and subjective sensations in the cold environment when the subjects wore ensemble with different clo values. Seven healthy male subjects participated in this experiment. This experiment was conducted in a climatic chamber with $-10^sC$ and 50%RH. Subjects wore five different kinds of ensemble[C1 (4.453 clo), C2 (3.452 clo), C3 (2.865 clo), C4 (2.387 clo), and C5 (2.280 clo)]. The experiment was composed of 20 min of rest period, 20min of treadmill exercise(6 km/h) period, 30 min of recovery period. We monitored skin temperature on 7 sites, clothing microclimate and subjective sensations. The clo value had positive correlations with mean skin temperature and clothing microclimate. The subjects feel more warm and humid as the clo value goes up. The subjects reported comfort when they wore C1 and C2 ensemble having over 3 clo value. However, they felt less comfortable during the exercise period since there was high humidity. Skin temperature on the extremities were more dramatically changed by the exercise rather than clo value. Thus it seems that in the cold environment, heat balance can mostly be controlled by the choice of clothing, and the clothes with high clo values can provide higher insulation. In conclusion, our findings suggest that it would be more effective to control clo value depending on the activity level for maintaining comfort level in the cold environment.

• 설비공학논문집
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• 제10권6호
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• pp.721-731
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• 1998

Recently, many researchers are studying the relation between thermal environment and human comfort. The purpose of this study was to obtain basic data which are necessary to determine the thermal comfort sensation and physiological responses for men in winter indoor environment. From January to February 1998, subject experiment was 40 times proceeded under twenty different conditions of air temperature and relative humidity with early-twenty male university students. We examined subjective evaluation, Electrocardiogram(ECG), Electroencephalogram(EEG) of subjects. The results of this study can be summarized as follows : The comfort zone of people in winter was achieved at Standard new effective temperature($SET^*$) $ 25.2^{\circ}C$, PMV range was obtained by Fanger's statistical calculation was －0.27＜PMV＜＋0.62, TSV range obtained subjects vote was －0.76＜TSV＜＋0.36. The largest difference of skin temperature was found at the calf area as air temperature changes. vote rate of human body presented calflongrightarrowheadlongrightarrowforearmlongrightarrowchestlongrightarrowabdo men in turn. Heart rate was decreased at low $SET^*$ and heart rate was increased at high $SET^*$ But there was no change at EEG.

• International Journal of Air-Conditioning and Refrigeration
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• 제8권1호
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• pp.73-83
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• 2000

The purpose of this study is to analyze and characterize the correlation of the thermal comfort sensation with physiological responses for men in winter indoor environment. A number of experiments were conducted under twenty different environmental conditions with college male students. Clinical information on each participant was reported in terms of electrocardiogram (ECG), electroencephalogram (EEG) and self-centered evaluation. The comfort zone in winter is found, throughout the study, at Standard New Effective Temperature (SET$T^+$) of 25.2$^{\circ}C$, Predicted Mean Vote (PMV) between 0.27 and 0.62, and Thermal Sensation Vote (TSV) in the range of -0.76 and 0.36. The largest difference in skin temperature is measured at the calf area with respect to air temperature changes. Skin sensitivity to environment temperature is explained as calf, head, chest and abdomen in descending order. Change in heat rate is analyzed to be in parallel with that of SET$T^+$.

• Animal Bioscience
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• 제35권11호
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• pp.1635-1648
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• 2022

Thermal stress due to extreme changes in the thermal environment is a critical issue in cattle production. Many previous findings have shown a decrease in feed intake, milk yield, growth rate, and reproductive efficiency of cattle when subjected to thermal stress. Therefore, selecting thermo-tolerant animals is the primary goal of the efficiency of breeding programs to reduce those adverse impacts. The recent advances in molecular genetics have provided significant breeding advantages that allow the identification of molecular markers in both beef and dairy cattle breeding, including marker-assisted selection (MAS) as a tool in selecting superior thermo-tolerant animals. Single-nucleotide polymorphisms (SNPs), which can be detected by DNA sequencing, are desirable DNA markers for MAS due to their abundance in the genome's coding and non-coding regions. Many SNPs in some genes (e.g., HSP70, HSP90, HSF1, EIF2AK4, HSBP1, HSPB8, HSPB7, MYO1A, and ATP1A1) in various breeds of cattle have been analyzed to play key roles in many cellular activities during thermal stress and protecting cells against stress, making them potential candidate genes for molecular markers of thermotolerance. This review highlights the associations of SNPs within these genes with thermotolerance traits (e.g., blood biochemistry and physiological responses) and suggests their potential use as MAS in thermotolerant cattle breeding.

• 한국산업융합학회 논문집
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• 제2권2호
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• pp.11-21
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• 1999

This objective of this paper is to investigate the evaluation and indiction of human thermal comfort in building environment. The issue of defining the boundaries of acceptable thermal comfort conditions in buildings and urban may have significant implication for building design and also may have urban design by climate considerations. And then it is to apply the thermal comfort condition to environmental design by using passive methods in Korea. Since 1920. architects have conducted studies to measure thermal comfort in houses under hot and humid conditions, while industrial hygienists have studied the effects of temperature and humidity on the performance of factory workers. Thermal comfort can be influenced by many variables. This paper conducted to review the previous researches and the human heat balance equation, and to analyse in order to reveal the meaning and usage of the thermal comfort index in two traditional essays, Fanger's PMV and Gagge's ET* Their comfort indexes compared with each other. They were based on human heat balance equation and psychological and physiological responses in the laboratory tests. The researchers and the architectural engineers using thermal comfort index shall be careful in decided the use of indexes and be necessary to recognize the value concept of the design criteria for thermal comfort. Therefore, The opinion of the authors is that different comfort standards have to apply for each building and urban with different climatic conditions.

• The Korean Journal of Physiology
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• 제24권1호
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• pp.171-180
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• 1990

In 19 cats anesthetized with ${\alpha}-chloralose$ effects of taurine and ${\beta}-alanine$ on the responses of wide dynamic range (WDR) cells to mechanical, chemical and thermal stimuli were investigated in the lumbar spinal cord of the cat. Also studied was an interaction of strychnine with taurine in affecting the activities of WDR cells. Following intravenous administration of taurine, the responses of WDR cells to all types of mechanical stimuli were markedly enhanced, demonstrating that the response to pressure was most sensitive to taurine action. When the receptive field was exposed to thermal stimuli ($50^{\circ}C$) for 20 sec. taurine increased activity of WDR cell to 169.5% of the control value. The $K^{+}$-induced activation of WDR cells was invariably suppressed after taurine administration. Intravenously administered strychnine remarkably reduced the enhanced response of WDR cell to natural stimuli resulting from intravenous administration of taurine. Also ${\beta}-alanine$ markedly activated the response of spinal dorsal horn cell to natural mechanical stimuli. These findings suggest that neutral amino acid and its derivative such as ${\beta}-alanine$ and taurine can enhance the response of WDR cells to different stimuli in cats.

• The Korean Journal of Physiology
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• 제30권1호
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• pp.85-96
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• 1996

Adenosine and its analogues are known to possess analgesic effects and to be involved in the opiate-induced antinociception as well. This study was designed to investigate the effects of three adenosine agonists, 5'- (N-cyclopropyl) -carboxamidoadenosine(CPCA), 5'-N-ethylcarboxamidoadeno-sine (NECA) and $N^6-cyclohexyladenosine$ (CHA) on the signal transmission in the spinal cord and also to elucidate mechanisms of their actions in the anesthetized cat. All the tested adenosine agonists(i.v,) exerted inhibitory effects on the responsiveness of the wide dynamic range (WDR) cells, the inhibitory action of CHA, an adenosine $A_1$ receptor agonist, $(80{\mu}g/Kg)$ being most weak. The intravenous CPCA, an adenosine $A_2$ receptor agonist, $(20{\mu}g\;/Kg)$ and NECA, nonspecific adenosine receptor agonist, $(20{\mu}g\;/Kg)$ inhibited the responses of WDR cells to pinch and C fiber stimulation more strongly than those to brush and A fiber stimulation. CPCA (i.v.) also suppressed the responses of WDR cells to thermal stimulus. And all the CPCA-induced inhibitions were caffeine-reversible. When CPCA was directly applied onto the spinal cord or intravenously administered into the spinal cat, on average, about three quarters of the CPCA-induced inhibitory effect was abolished. On the other hand, in the animal with spinal lesions in the ipsilateral dorsolateral area, the CPCA-induced inhibition was comparable to that observed in the spinal cats. In conclusion, this study shows that adenosine agonists strongly suppress the responses of WDR cells to pinch, C fiber stimulation and thermal stimuli mainly through the supraspinal adenosine $A_2-receptors$.

• 한국의류산업학회지
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• 제16권1호
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• pp.167-174
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• 2014

The physical properties of textile materials and thermal physiological responses of the human subjects were evaluated with 4 different types of the army combat uniforms including US, German, Korean and general uniforms for this study. 8 male adults were used as the human subjects and the tests were done in the environmental chamber that was $25{\pm}0.1^{\circ}C$ of temperature, $65{\pm}5%$ of relative humidity and below 0.3 m/sec of air velocity. The test protocol consisted the rest period for 20 min., the exercise period for 20 min., the rest period for 20 min., the exercise period under wind condition for 20 min., and the recovery period for 20 min. The human subjects walked with 4.5 km/hr for 10 min., ran 7.5 km/hr for 10 min. during the first exercise period and walked and ran with the same speeds under 3.5 m/sec of the air velocity that simulated outdoor condition during the second exercise period. The test results of the study were as follows; The wind condition affected the skin and microclimate temperature of the human subjects lower compared to without wind condition, but had insignificant effect on the humidity control. The low air permeability of Korean uniform caused blocking the elimination of the humidity from the body and the regulation of body temperature. However, Korean uniforms could be the excellent one with the designs considering the ventilation of the uniforms and the textile fabrics with better air permeability.

• 한국의류학회지
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• 제28권5호
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• pp.713-722
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• 2004

This study examined the effects of two kinds of functional sun hats through a head-manikin test and a climatic chamber trial for farm workers in summer. Experiment was composed of four conditions. The first condition was the condition without any hat (Control). The second was the condition with a sun hat on the market (Hat A). The third was the condition with a functional sun hat made of reflective fabric (Hat B). The last was the condition with a functional sun hat having a ventilating structure as well as reflective fabric (Hat C). For the subjects in the climatic chamber trials, 12 healthy males volunteered. Air temperature, relative humidity and globe temperature in the chamber was maintained at $33{\pm}0.5^{\circ}C,\;65{\pm}5%RH\;and\;39{\pm}1^{\circ}C\;(WBGT\;33^{\circ}C)$. Subjects did a simulated red pepper-work (50-min work and 10-min rest, twice repetition) for 120 min. As the result of head-manikin test, the surface temperature on middle of back-neck was the lowest in Hat B of four conditions and the surface temperature on top of head was the lowest in Hat C. As the result of climatic chamber trials, there were apparent differences between with (Hat A, Hat B, Hat C) and without a sun hat (Control). In rectal temperature ($T_{re}$), mean skin temperature ($\={T}_{sk}$), heart rate (HR), total sweat rate (TSR), The physiological heat strain was less in the condition with hats than in the condition without a sun hat. As the increasing rate in Tre, Hat B is the most effective hat for alleviation heat strain. As the subjective responses, Hat B was the most effective hat for thermal comfort even though the difference was not significant. Hat C was less effective than Hat B and the reason might be the increase of weight due to inserting the ventilating structure.