• Title/Summary/Keyword: Standard Effective Temperature

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Evaluation of Korean Thermal Sensation in Office Buildings During the Summer Season (여름철 사무실내 한국인의 온열감 평가)

  • Bae, G.N.;Lee, C.H.;Lee, C.S.
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.7 no.2
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    • pp.341-352
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    • 1995
  • In this study, thermal parameters were measured and 213 occupants were also questioned in three office buildings located in Seoul during the summer season. Predicted mean vote-predicted percentage of dissatisfied(PMV-PPD) and standard new effective temperature(SET*) were used for evaluating Korean thermal sensation. The distribution of thermal sensation vote(TSV) and percentage of dissatisfied(PD) is very similar to that of PMV and PPD. By regression analysis, the following regression equation was obtained; TSV=0.339SET*-8.583. In this case, neutral temperature and comfort range are $25.3^{\circ}C$, $23.8{\sim}26.8^{\circ}C$ respectively. Present experimental results obtained from the field study is less sensitive to the temperature change than those obtained from the climate chamber study in Korea. But, thermal sensations are similar to each other near the neutral point. The neutral temperature and comfort range obtained by this experiment are higher than those of ANSI/ASHRAE Standard 55-1974 about $1.4{\sim}1.8^{\circ}C$.

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A study on characteristics of thermal comfort for artificial environmental experiment in winter (동계 인공환경실험에 의한 온열쾌적특성 연구)

  • 박종일;김경훈;정성일
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.10 no.6
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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.

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Characteristics of Thermal Comfort in Environment Chamber for Winter

  • Kim, Kyung-Hoon;Park, Jong-Il;Song, Yong-Gil
    • International Journal of Air-Conditioning and Refrigeration
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    • v.8 no.1
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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$T^+$.

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THE STELLAR COLOR-TEMPERATURE RELATION IN ULTRAVIOLET REGION (자외선 영역에서 별의 색지수와 온도의 상관관계)

  • 최영준;한원용;강영운;이우백
    • Journal of Astronomy and Space Sciences
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    • v.15 no.2
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    • pp.321-333
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    • 1998
  • In order to derive the UV color - effective temperature relation, we calculated the effective temperature and ultraviolet color index for about 118 IUE standard stars. Using differential correction method, the effective temperature was obtained by the best fittings of IUE low-dispersion spectra to the Kurucz model (1993), and the UV color index was calculated from the magnitude differences of the UV wavelength between 2750 $\AA$ and 2950 $\AA$. The temperature determined by the Kurucz model fittings was consistent with that obtained by other investigators (Malagnini & Morossi 1990, Malagnini et al. 1986), except for the low temperature stars. The relations between UV color - effective temperature also was similar to that in Kurucz model.

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DETERMINATION OF STELLAR SURFACE TEMPERAURE USING ULTRAVIOLET SPECTRA (자외선 스펙트럼을 이용한 별의 표면온도 결정)

  • 강영운;지나현;한미려;최영준;한원용;이우백
    • Journal of Astronomy and Space Sciences
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    • v.15 no.1
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    • pp.91-100
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    • 1998
  • Color indexes and effective temperatures for 25 standard stars have been determined as a pilot project which show a relationship between color index and effective temperature in ultraviolet region. The effective temperature was determined by comparing energy distribution curves derived from the IUE low dispersion spectra with Kurucz atmosphere model. The UV color index was deduced by integrating fluxes in $300{\AA}$ interval of the IUE low disperion spectra. The relation between color index and effective temperature in ultraviolet is similar with that of optical region.

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A study on the washing efficiency with various washing conditions - Focus on detergent concentration and temperature - (인공오염포의 세탁조건에 따른 세척효율에 관한 연구 - 세제농도와 용수온도를 중심으로 -)

  • Choi, In-Ryu;Kim, Taemi
    • The Research Journal of the Costume Culture
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    • v.22 no.3
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    • pp.503-510
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    • 2014
  • Nowdays, costumer's washing behavior were often times for remove to light-duty dirt. The purpose of this study is to provide the most effective washing conditions of detergent concentration and temperature conditions for help save energy and water resources required to the washing process. Washing conditions were as follows: 2 kinds of detergents and 4 types of artificially soiled fabrics were used. Detergent concentration was 0%, -10%, and -20% below the recommended conc. of manufacturer's standard. Temperature of bath was $20^{\circ}C$ and $40^{\circ}C$. The results of this study were as follows: First, washing performances of all kind of artificially soiled fabric improved as the temperature of bath at $40^{\circ}C$. Second, the test was conducted under the condition of decreasing respectively -10% and -20% below of the recommended concentration of manufacturer's standard detergent. The average of washing efficiency was not considerably affected by the reduction of 10% below of manufacturer's standard. Third, in case of the water temperature were $20^{\circ}C$, polyester/cotton blended fiber were higher degree of washing efficiency than cotton fiber.

Evaluation of Effective Temperature for Estimate Design Thermal Loads in Steel Deck of Steel Box Girder Bridges (강상자형교의 강바닥판에서 설계온도하중을 위한 유효온도 산정)

  • Shin, Dong-Wook;Kim, Kyoung-Nam;Choi, Chul-Ho;Lee, Seong-Haeng
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.17 no.6
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    • pp.77-87
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    • 2013
  • A present LSD (limited state design) code for temperature load in the domestic bridge design has applied a uniform standard for various bridge types. In this study, in order to calculate the effective temperature, a specimen of steel box girder bridge section with real size dimension was manufactured. For a year, the temperature data were measured at the 18 point in steel deck of steel box girder bridges specimen. Effective temperature within the cross section according to atmospheric temperature was calculated by this experiment data. The analyzed results were very similar correlation when compared with the effective temperature of the Euro Code. Therefore, the effective temperature which calculated based on the present data could be used as the basic data in order to present to the appropriate design criteria for the thermal loads on the domestic bridge design.

Experimental Study on the Effective Temperature Calculation of Concrete Box Girder Bridge (콘크리트 박스거더교의 설계 유효온도 산정을 위한 실험적 연구)

  • Lee, Seong-Haeng
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.21 no.11
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    • pp.740-745
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    • 2020
  • To calculate the reasonable design temperature load of a concrete box girder bridge, one bridge test specimen was made. The temperature gauges installed on the bridge test specimen measured 48 sets of temperature per day at 30-minute intervals during the summer and winter periods of one year. The temperature measured at each station was treated statistically to calculate the trend line and standard error, and the temperature distribution and trend line at the representative station were presented. The maximum effective temperature and the lowest effective temperature were calculated from the air temperature suggested by Euro code. The maximum effective temperature was calculated to be 1.5 to 2℃ higher than the Euro code at 35℃ and above. In comparison, the lowest effective temperature was 0.5 to 1.1℃ lower at -13℃ to-19℃. Compared to the effective temperature of this study according to the highest and lowest 50-year frequency of the Yangsan region, the highest effective temperature was 4.7℃ higher, and the lowest effective temperature was 4.5℃ lower. Considering the increasing climate change and reflecting the results of this analysis, it is deemed necessary to make the current temperature design standards larger.

Estimation of Climatological Standard Deviation Distribution (기후학적 평년 표준편차 분포도의 상세화)

  • Kim, Jin-Hee;Kim, Soo-ock;Kim, Dae-jun
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.19 no.3
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    • pp.93-101
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    • 2017
  • The distribution of inter-annual variation in temperature would help evaluate the likelihood of a climatic risk and assess suitable zones of crops under climate change. In this study, we evaluated two methods to estimate the standard deviation of temperature in the areas where weather information is limited. We calculated the monthly standard deviation of temperature by collecting temperature at 0600 and 1500 local standard time from 10 automated weather stations (AWS). These weather stations were installed in the range of 8 to 1,073m above sea level within a mountainous catchment for 2011-2015. The observed values were compared with estimates, which were calculated using a geospatial correction scheme to derive the site-specific temperature. Those estimates explained 88 and 86% of the temperature variations at 0600 and 1500 LST, respectively. However, it often underestimated the temperatures. In the spring and fall, it tended to had different variance (e.g., increasing or decreasing pattern) from lower to higher elevation with the observed values. A regression analysis was also conducted to quantify the relationship between the standard deviation in temperature and the topography. The regression equation explained a relatively large variation of the monthly standard deviation when lapse-rate corrected temperature, basic topographical variables (e.g., slope, and aspect) and topographical variables related to temperature (e.g., thermal belt, cold air drainage, and brightness index) were used. The coefficient of determination for the regression analysis ranged between 0.46 and 0.98. It was expected that the regression model could account for 70% of the spatial variation of the standard deviation when the monthly standard deviation was predicted by using the minimum-maximum effective range of topographical variables for the area.

Customized Eyelid Warming Control Technique Using EEG Data in a Warming Mask for Sleep Induction (수면유도용 온열안대를 위한 뇌파기반의 맞춤형 온열제어 기법)

  • Han, Hyegyeong;Lee, Byung Mun
    • Journal of Korea Multimedia Society
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    • v.24 no.8
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    • pp.1149-1160
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    • 2021
  • Lack of sleep time increases risks of fatigue, hypomnesis, decreased emotional stability, indigestion, and dementia. The risks can be reduced by providing eyelid-warming, inducing sleep and improving sleep quality. However, effective warming temperature to an person varies depending on physical condition and the individual. The various types of frequencies can be identified in brain wave from a person and amount of frequencies is also changed continuously before and after sleep. Therefore we can identify the user's sleep stage with brain wave, namely EEG. Effective sleep induction is possible if warming temperature to a person is controlled based on EEG. In this paper, we propose customized warming control techniques based on EEG for a efficient and effective sleep induction. As an experiment, sleep induction effects of standard sleep mask and customized temperature control techniques sleep mask are compared. EEG data and warming temperature were measured in 100 experiments. At customized warming control techniques, experiments showed that the ratio of alpha and theta waves increased by 3.21%p and the time to sleep decreased by 85 seconds. It will contribute to effective sleep induction and performance verification methods in customized sleep mask systems.