• Title, Summary, Keyword: Temperature

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Indoor Neutral Temperature Range using Temperature and Humidity Perception Assessment

  • Yang, Wonyoung
    • KIEAE Journal
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    • v.16 no.5
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    • pp.29-37
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    • 2016
  • Purpose: Indoor thermal comfort can be identified by combination of temperature, humidity, and air flow, etc. However, most thermal indexes in regard to thermal comfort are temperature dominant since it has been considered as a significant factor affecting to indoor thermal comfort The purposes of this study are to investigate indoor neutral temperature range of young Koreans with humidity perception, and to introduce a neutral temperature for temperature preference as well as temperature sensation in order to define the neutral temperature range chosen by occupants. It could be used as basic data for heating and cooling. Method: 26 research participants volunteered in 7 thermal conditions ($18^{\circ}C$ RH 30%, $18^{\circ}C$ RH 60%, $24^{\circ}C$ RH 30%, $24^{\circ}C$ RH 40%, $24^{\circ}C$ RH 60%, $30^{\circ}C$ RH 30%, $30^{\circ}C$ RH 60%) and completed subjective assessment in regard to temperature/humidity sensation and preference twice per condition in an indoor environmental chamber. Result: In RH 30%, sensation neutral temperature was $25.1^{\circ}C$ for men and $27.0^{\circ}C$ for women, and preference neutral temperature was $25.5^{\circ}C$ for men and $27.8^{\circ}C$ for women. In RH 60%, sensation neutral temperature was $23.6^{\circ}C$ for men and $25.9^{\circ}C$ for women, and preference neutral temperature was $23.4^{\circ}C$ for men and $26.3^{\circ}C$ for women. Neutral temperature increased with increasing relative humidity. Women were sensitive to humidity changes. Men expressed humidity changes as temperature variations. In most conditions, preference neutral temperatures were higher than sensation neutral temperatures, however, the preference neutral temperature for men in humid condition was lower than the sensation neutral temperature.

A High Accuracy and Fast Hybrid On-Chip Temperature Sensor (고정밀 고속 하이브리드 온 칩 온도센서)

  • Kim, Tae-Woo;Yun, Jin-Guk;Woo, Ki-Chan;Hwang, Seon-Kwang;Yang, Byung-Do
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.9
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    • pp.1747-1754
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    • 2016
  • This paper presents a high accuracy and fast hybrid on-chip temperature sensor. The proposed temperature sensor combines a SAR type temperature sensor with a ${\Sigma}{\Delta}$ type temperature sensor. The SAR type temperature sensor has fast temperature searching time but it has more error than the ${\Sigma}{\Delta}$ type temperature sensor. The ${\Sigma}{\Delta}$ type temperature sensor is accurate but it is slower than the SAR type temperature sensor. The proposed temperature sensor uses both the SAR and ${\Sigma}{\Delta}$ type temperature sensors, so that the proposed temperature sensor has high accuracy and fast temperature searching. Also, the proposed temperature sensor includes a temperature error compensating circuit by storing the temperature errors in a memory circuit after chip fabrication. The proposed temperature sensor was fabricated in 3.3V CMOS $0.35{\mu}m$ process. Its temperature resolution, power consumption, and area are $0.15^{\circ}C$, $540{\mu}W$, and $1.2mm^2$, respectively.

Women's Comfort Temperature Range and Dynamic Temperature Change for Maintaining Thermal Comfort in Low Temperature Environment (저온환경에서 여성 온열쾌적성 유지를 위한 쾌적온도범위 및 동적 온도변화 연구)

  • Kim, Soyoung;Lee, Okkyung;Lee, Heeran
    • Fashion & Textile Research Journal
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    • v.22 no.6
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    • pp.853-861
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    • 2020
  • Various types of clothing are being developed to boost thermal comfort during cold winters along with research on change of body temperature when heating is applied. There is a noticeable behavioral difference by gender when using heating panels in a cold environment; however, research on women has been insufficient. This study find a temperature range that provides sustainable thermal comfort in a low temperature environment by observing temperature and change of temperature when subjects are classified according to physical activities or cold sensitivities. For the study results, 8 women in their 20s were subjected to experiment in a low temperature environment for 75 minutes (sitting position: 30 min., running: 15 min., and sitting position: 30 min.). Subjects were asked to turn on/off the heating panel freely to analyze the range of comfortable temperature and clothing microclimate; in addition, skin temperature and heating panel temperature were measured and analyzed at 9 points. As a result, temperature at which subjects turn on and off the heating panel indicated a statistically meaningful difference between the cold sensitivity group depending on exercise or non-exercise. The range of comfortable abdomen temperature was wider than the lower back and was significantly reduced when the subject was running. The range of comfortable temperature was also largest for the heating panel temperature, microclimate, and skin temperature in suggesting that adequate adjustment will be required depending on the surrounding environment or movement of the wearer.

Particle Size of Aerosol from 0.25% Cadmium Chloride Nebulizing Solution for Inhalation Toxicology Study (흡입독성 연구에 이용될 0.25% 염화카드뮴 네뷸라이징 용액 에어로졸의 입경)

  • Jeung Jae Yeal;Lee Ki Nam
    • Journal of Physiology & Pathology in Korean Medicine
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    • v.17 no.5
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    • pp.1257-1263
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    • 2003
  • The modified engineering methodology and the modified electronic circuit in classical ultrasonic principles were applied to ultrasonic aerosol nebulizer for inhalation toxicology study of cadmium aerosol. 1532.96ppm Cd nebulizing solution was used to generate cadmium aerosol for particle size analysis with the modifying source and inlet temperatures. The results of particle size analysis for cadmium aerosol were as following. The highest particle counting for source temperature 20℃ was 399.75 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 50℃ was 399.70 × 10² in inlet temperature 50℃ and particle diameter 0.75㎛. The highest particle counting for source temperature 70℃ was 411.14 × 10² in inlet temperature 100℃ and particle diameter 0.75㎛. The ranges of geometric mean diameter were 0.74-0.79㎛ in source temperature 20℃, 0.65-0.72㎛ in source temperature 50℃, and 0.65-0.80㎛ in source temperature 70℃. The smallest geometric mean diameter was 0.65㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest geometric mean diameter was 0.80㎛ in source temperature 70℃ and inlet temperature 100℃. The ranges of geometric standard deviation were 1.71-1.80 in source temperature 20℃, 1.27-1.61 in source temperature 50℃, and 1.27-2.29 in source temperature 70℃. The lowest geometric standard deviation was 1.27 in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the highest geometric standard deviation was 2.29 in source temperature 70℃ and inlet temperature 100℃. Generated aerosol for cadmium inhalation toxicology study was polydisperse aerosol with the above geometric standard deviation 1.2. The ranges of mass median diameter(MMD) were 1.75-2.25㎛ in source temperature 20℃, 1.27-1.61㎛ in source temperature 50℃, and 1.27-2.29㎛ in source temperature 70℃. The smallest MMD was 1.27㎛ in source temperature 50, 70℃ and inlet temperature 20, 50℃, and the largest MMD was 2.29㎛ in source temperature 70℃ and inlet temperature 100℃. Cadmium chloride concentration in nebulizing solution affected the particle size and distribution of cadium aerosol in air. MMO for inhalation toxicology testing in OECD and EU is less than 3㎛ and EPA guidance is less than 4㎛. In our results, in source temperatures of 20, 50, 70℃, and inlet temperatures of 20, 50, 100, 150, 200, 250℃ were conformed to the those guidance.

Change in the Plant Temperature of Tomato by Fogging and Airflow in Plastic Greenhouse (포그분사 및 공기유동에 의한 온실재배 토마토의 엽온 변화)

  • Nam, Sang-Woon;Kim, Young-Shik;Seo, Dong-Uk
    • Journal of Bio-Environment Control
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    • v.23 no.1
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    • pp.11-18
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    • 2014
  • To investigate the influence of surrounding environment on the plant temperature and examine the effect of plant temperature control by fogging and airflow, plant temperature of tomato, inside and outside air temperature and relative humidity, solar radiation and wind speed were measured and analyzed under various experimental conditions in plastic greenhouse with two-fluid fogging systems and air circulation fans. According to the analysis of plant temperature and the change of inside and outside air temperature in each condition, inside air temperature and plant temperature were significantly higher than outside air temperature in the control and shading condition. However, in the fogging condition, inside air temperature was lower or slightly higher than outside air temperature. It showed that plant temperature could be kept with the temperature similar to or lower than inside air temperature in fogging and airflow condition. To derive the relationship between surrounding environmental factor and plant temperature, we did multiple regression analysis. The optimum regression equation for the temperature difference between plant and air included solar radiation, wind speed and vapor pressure deficit and RMS error was $0.8^{\circ}C$. To investigate whether the fogging and airflow contribute to reduce high temperature stress of plant, photosynthetic rate of tomato leaf was measured under the experimental conditions. Photosynthetic rate was the highest when using both fogging and airflow, and then fogging, airflow and lastly the control. So, we could assume that fogging and airflow can make better effect of plant temperature control to reduce high temperature stress of plant which can increase photosynthetic rate. It showed that the temperature difference between plant and air was highly affected by surrounding environment. Also, we could estimate plant temperature by measuring the surrounding environment, and use it for environment control to reduce the high temperature stress of plant. In addition, by using fogging and airflow, we can decrease temperature difference between plant and air, increase photosynthetic rate, and make proper environment for plants. We could conclude that both fogging and airflow are effective to reduce the high temperature stress of plant.

An Experimental Study on the Shortest optimum time for Body Temperature measurement (체온측정에 필요한 최단적정시간규명을 위한 실험적 연구)

  • 홍여신;이선옥
    • Journal of Korean Academy of Nursing
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    • v.5 no.2
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    • pp.38-50
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    • 1975
  • This study was conducted to find the shortest optimum time for taking oral temperature and axillary temperature, which does not affect reliability of body temperature. For this purpose, first, the time at which all the samples are reaching maximum temperature is identified Second, the mean maximum temperature is compared with the mean temperature of each consecutive measurement by T-test to find the time at which no significant changes in temperature occurs along time sequence. Third, optimum temperatures are set at points of -0.2℉, -0.4℉, -0.6℉, -0.8℉, -1.0℉, -1.2℉, -1.4℉, from maximum temperature. A point of time at which 90% of samples reach at optimum temperature is identified and defined as optimum time. The study sample, a total of 164 cases were divided into two groups according to their measured body temperature. The group with body temperature below 37 $^{\circ}C$(A group) and above 37$^{\circ}$1'C (B group) were compared on the time required to reach maximum temperature and optimum temperature. The results are as follow. 1. The time required for total sample to reach maximum temperature was 13 minutes in both groups by oral method, 15 minutes in A group and 13 minutes in B group by axillary method. Time required for 90 % of cases reach maximum temperature by oral method was 10 minutes in both group. By axillary method, 12 minutes in A group. (Ref: table 2) 2. Statistical analysis by means of T-test, the time which does not show a significant change by oral method were 12 minutes in A group and 11 minutes in B group, and by axillary method 14 minutes in A group and 11 minutes in B group. (Ref: table 5, 6.) 3. Where optimum temperature was defined as maximum temperature minus 0.2 ℉, optimum time was found 8 minutes in both groups by oral method, and 11 minutes in A group and 9 minutes in B group by axillary method 4. Where optimum temperature was defined as maximum temperature minus 0.4 ℉, optimum time was found 7 minutes in A group and 6 minutes in B group by oral method, and 9 minutes in A group and 7 minutes in B group by axillary method 5. Where optimum temperature was defined as maximum temperature minus 0.8 ℉, optimum time was found 6 minutes in A group and 6 minutes in B group by axillary method (Ref: table 7, 8, 9, 10) 6. The commonly practiced temperature taking time, 3 minutes in oral method and 5 minutes in axillary method can be accepted as pertinent when physiological variation of body temperature at the mean level of -1, 2 ℉ is accepted. 7. The difference in time required to resister maximum temperature was compared between the group with body temperature below 37$^{\circ}C$ and above 37$^{\circ}$1'C, and found no significant difference in oral mettled and 1 - 4 minute difference in axillary method with shorter time requirement in feverish group.

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The Design of an Automatic System for Dairy Cattle Breeding I - The Choice of Temperature Sensor for Body Temperature Measuring - (낙농의 자동화 시스템 구성 I - 체온 감지 온도센서의 선정 -)

  • 김형주;정길도;한병성;김용준;김동원;김명순
    • Journal of Biosystems Engineering
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    • v.23 no.1
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    • pp.83-90
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    • 1998
  • In this paper the automatic system for dairy cattle has been desisted such as body temperature measuring unit, feed supplying unit and temperature control unit. Since e disease is strongly related to the body temperature of cattle, early detection of the abnormal temperature would prevent the severe problems which nay occur in dairy farms. An electronic component AD590J is used as temperature sensor for the system, The device is highly robust against the noise since the output signal is the current so it can be applied to a long distance sensing The resolution of signal is 0.1$^{\circ}C$ and the current is 10㎷ Also 12-bit A/D converter is desisted fir interfacing the sensor with a one-chip microprocessor. A temperature measuring experiment using the developed system has been done for measuring the temperature of human beings and the system was proven to be useful for measuring the body temperature of dairy cattle properly. A geared AC motor is used for the feed supplying unit The heater and fm are used as temperature control unit. The feed supplying unit and temperature control unit are well operating in the laboratory experiment.

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Deformation Properties of TiC-Mo Eutectic Composite at High Temperature (TiC-Mo 공정복합재료의 고온 변형특성)

  • Shin, Soon-Gi
    • Korean Journal of Materials Research
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    • v.23 no.10
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    • pp.568-573
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    • 2013
  • The deformation properties of a TiC-Mo eutectic composite were investigated in a compression test at temperatures ranging from room temperature to 2053 K and at strain rates ranging from $3.9{\times}10^{-5}s^{-1}$ to $4.9{\times}10^{-3}s^{-1}$. It was found that this material shows excellent high-temperature strength as well as appreciable room-temperature toughness, suggesting that the material is a good candidate for high-temperature application as a structure material. At a low-temperature, high strength is observed. The deformation behavior is different among the three temperature ranges tested here, i.e., low, intermediate and high. At an intermediate temperature, no yield drop occurs, and from the beginning the work hardening level is high. At a high temperature, a yield drop occurs again, after which deformation proceeds with nearly constant stress. The temperature- and yield-stress-dependence of the strain is the strongest in this case among the three temperature ranges. The observed high-temperature deformation behavior suggests that the excellent high-temperature strength is due to the constraining of the deformation in the Mo phase by the thin TiC components, which is considerably stronger than bulk TiC. It is also concluded that the appreciable room-temperature toughness is ascribed to the frequent branching of crack paths as well as to the plastic deformation of the Mo phase.

Daily Changes in Red-Pepper Leaf Surface Temperature with Air and Soil Surface Temperatures

  • Eom, Ki-Cheol;Lee, Byung-Kook;Kim, Young-Sook;Eom, Ho-Yong
    • Korean Journal of Soil Science and Fertilizer
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    • v.47 no.5
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    • pp.345-350
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    • 2014
  • This study was conducted to investigate the changes in daily surface temperature of red pepper leaf compared to air and soil surface temperature. The maximum, minimum and average daily temperatures of red pepper leaf were 27.80, 11.40 and $19.01^{\circ}C$, respectively, which were lower by 0.10, 7.60 and $3.86^{\circ}C$ than air temperature, respectively, and lower by 15.00, 0.0 and $4.38^{\circ}C$ than soil surface temperature, respectively. Mean deviations of the difference between measured and estimated temperature by the E&E Model (Eom & Eom, 2013) for the air and surface temperature of red pepper leaf and soil were 0.64, 1.82 and $4.77^{\circ}C$, respectively. The relationships between measured and estimated scaled factor of the air and surface temperature of red pepper leaf and soil were very close to the 1:1 line. Difference between air and surface temperature of red pepper leaf showed a linear decreasing function with the surface temperature of red pepper leaf. Difference between soil surface temperature and air and surface temperature of red pepper leaf linearly increased with the soil surface temperature.

A Study on the Temperature Characteristics of the Floor Cooling System of Mock-up Experimentent (Mock-up실험에 의한 바닥복사 냉방시스템의 온도특성에 관한 연구)

  • Yoo, Ho-Chun;Lee, Young-A
    • Journal of the Korean Solar Energy Society
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    • v.28 no.6
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    • pp.48-57
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    • 2008
  • The research analyzed the distribution of the indoor temperatures of a radiant floor cooling system through mock-up experiments. It investigated the temperature difference of feed water, the vertical temperature difference of indoor air, the temperature difference of floor surface, and so on. The following is the results of the research. First, the research shows that the difference between indoor temperature and outside temperature was the smallest when the temperature of feed water was set at 16$^{\circ}C$. In addition, the temperature changes according to indoor positions (wall, room, floor, and ceiling) were the most uniform. Thus, the research found that the cold water temperature of 16$^{\circ}C$ is the most proper. In addition, it confirmed that the feed water temperature of 18$^{\circ}C$ is effective because the temperature can lower the temperature of a room to 13.55$^{\circ}C$, which is lower than the temperature of a non-cooling mode. Second, an investigation on the temperature distribution of vertical air in indoor space shows that the temperature distribution had a difference of 0.2 to 1.9$^{\circ}C$ on the average, which satisfies the range of 3.0$^{\circ}C$ in the standard of ISO.