• Title/Summary/Keyword: Surface Temperature

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A Study on the Thermal Performance of Embossing Surface Sandwich Panel During the Summer (여름철 엠보싱 샌드위치 패널의 열적 성능에 관한 연구 -평판 샌드위치 패널과 비교를 중심으로-)

  • 손철수
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.12 no.10
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    • pp.917-924
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    • 2000
  • The purpose of this research is to investigate the thermal performance of embossing surface sandwich panel and flat surface sandwich panel during the summer. To do this research, thermal performances in summer season at the six points of embossing surface sandwich panel and flat surface sandwich panel are investigated focusing on the temperature. Three kinds of embossing surface sandwich panel and one kind of flat surface sandwich panel are used for this research. At the same size of sandwich panel, the average temperature differences of flat surface sandwich panel between average temperature at the 0.5 mm below copper plate and average outside air temperature and surface temperature are higher than those of embossing surface sandwich panel. The average heat transfer rate of flat surface sandwich panel is higher than that of embossing surface sandwich panel. More study will be needed about the size of diameter and height of embossing, and materials of embossing surface sandwich panel.

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Development of Road Surface Temperature Prediction Model using the Unified Model output (UM-Road) (UM 자료를 이용한 노면온도예측모델(UM-Road)의 개발)

  • Park, Moon-Soo;Joo, Seung Jin;Son, Young Tae
    • Atmosphere
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    • v.24 no.4
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    • pp.471-479
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    • 2014
  • A road surface temperature prediction model (UM-Road) using input data of the Unified Model (UM) output and road physical properties is developed and verified with the use of the observed data at road weather information system. The UM outputs of air temperature, relative humidity, wind speed, downward shortwave radiation, net longwave radiation, precipitation and the road properties such as slope angles, albedo, thermal conductivity, heat capacity at maximum 7 depth are used. The net radiation is computed by a surface radiation energy balance, the ground heat flux at surface is estimated by a surface energy balance based on the Monin-Obukhov similarity, the ground heat transfer process is applied to predict the road surface temperature. If the observed road surface temperature exists, the simulated road surface temperature is corrected by mean bias during the last 24 hours. The developed UM-Road is verified using the observed data at road side for the period from 21 to 31 March 2013. It is found that the UM-Road simulates the diurnal trend and peak values of road surface temperature very well and the 50% (90%) of temperature difference lies within ${\pm}1.5^{\circ}C$ (${\pm}2.5^{\circ}C$) except for precipitation case.

Comparison of Surface Temperatures between Thermal Infrared Image and Landsat 8 Satellite (열적외 영상과 Landsat 8 위성으로부터 관측된 지표면 온도 비교)

  • Cho, Chaeyoon;Jee, Joon-Bum;Park, Moon-Soo;Park, Sung-Hwa;Choi, Young-Jean
    • Journal of Korean Society for Atmospheric Environment
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    • v.32 no.1
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    • pp.46-56
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    • 2016
  • In order to analyze the surface temperature in accordance with the surface material, surface temperatures between Thermal InfraRed Image (TIRI) and Landsat 8 satellite observed at the commercial area (Gwanghwamun) and residential area (Jungnang) are compared. The surface temperature from TIRI had applied atmospheric correction and compared with that from Landsat 8. The surface temperatures from Landsat 8 at Gwanghwamun and Jungnang are underestimated in comparison with that from TIRI. The difference of surface temperature between the two methods is greater in summer than in winter. When the analysis area was divided into detailed regions, depending on the material and the position of the surface, correlation of surface temperature between TIRI with Landsat 8 is as low as 0.29 (Gwanghwamun) and 0.18 (Jungnang), respectively. The results were caused from the resolution difference between the two methods. While the surface temperatures of each zone from Landsat 8 were observed almost constant, high-resolution TIRI observed relatively precise surface temperatures. When the each area was averaged as one space, correlation of surface temperature between TIRIs and Landsat 8 is more than 0.95. The spatially averaged surface temperature is higher at Jungnang, representing residential areas, than at Gwanghwamun, representing commercial areas. As a result, the observation of high resolution is required in order to observe the precise surface temperature. This is because it appears that the spatial distribution of the various surface temperature in the range of micro-scale according to the conditions of the ground surface.

IMPROVING EMISSIVITY ESTIMATION IN RETRIEVING LAND SURFACE TEMPERATURE WITH MODIS DATA

  • Lin, Tang-Huang;Liu, Gin-Rong;Tsai, Fuan;Hsu, Ming-Chang
    • Proceedings of the KSRS Conference
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    • 2007.10a
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    • pp.337-340
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    • 2007
  • Many researches conducted to investigate the relationship between surface emissivity and surface temperature in the past two decades and pointed out that the emissivity play a key role in applying remote sensing data to retrieve surface temperature. The task of surface temperature estimation is so important in many research fields, such as earth energy budgets, evapotranspiration, drought, global change and heat island effect. Therefore, it is indispensable to develop an effective and accurate technique to estimate the emissivity for accurate surface temperature estimations. This study developed an improved emissivity estimation technique for the use of surface temperature retrievals with MODIS data. The result of applying this improved technique using Band 31 of MODIS shows that the accuracy of estimated surface temperatures will be improved. This study also uses MODIS data observed in 2005 to establish the relationship between the surface emissivity correction factor and NDVI. Through the use of these correction factors, the land surface temperature can be retrieved more accurate with MODIS data.

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Estimation of Hardened Layer Dimensions Using Multi-Point Temperature Monitoring in Laser Surface Hardening Processes (레이저 표면 경화 공정에서 다점 온도 모니터링을 통한 경화층 크기 예측)

  • 우현구
    • Journal of Institute of Control, Robotics and Systems
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    • v.9 no.12
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    • pp.1048-1054
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    • 2003
  • In laser surface hardening processes, the geometrical parameters such as the depth and the width of a hardened layer can be utilized to assess the hardened layer quality. However, accurate monitoring of the geometrical parameters for on-line process control as well as for on-line quality evaluation is very difficult because the hardened layer is formed beneath a material surface and is not visible. Therefore, temperature monitoring of a point of specimen surface has most frequently been used as a process monitoring method. But, a hardened layer depends on the temperature distribution and the thermal history of a specimen during laser surface hardening processing. So, this paper describes the estimation results of the geometric parameters using multi-point surface temperature monitoring. A series of hardening experiments were performed to find the relationships between the geometric parameters and the measured temperature. Estimation results using a neural network show the enhanced effectiveness of multi-point surface temperature monitoring compared to one-point monitoring.

NASA Model Deviation Correction for Accuracy Improvement of Land Surface Temperature Extraction in Broad Region (NASA 모델의 편차보정에 의한 광역지역의 지표온도산출 정확도 향상)

  • Um Dae-Yong;Park Joon-Kyu;Kim Min-Kyu;Kang Joon-Mook
    • Proceedings of the Korean Society of Surveying, Geodesy, Photogrammetry, and Cartography Conference
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    • 2006.04a
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    • pp.281-286
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    • 2006
  • In this study, acquired time series Landsat TM/ETM+ image to extract land surface temperature for wide-area region and executed geometric correction and radiometric correction. And extracted land surface temperature using NASA Model, and I achieved the first correction by perform land coverage category for study region and applies characteristic emission rate. Land surface temperature that acquire by the first correction analyzed correlation with Meteorological Administration's temperature data by regression analysis, and established correction formula. And I wished to improve accuracy of land surface temperature extraction using satellite image by second correcting deviations between two datas using establishing correction formula. As a result, land surface temperature that acquire by 1,2th correction could correct in mean deviation of about ${\pm}3.0^{\circ}C$ with Meteorological Administration data. Also, could acquire land surface temperature about study region by relative high accuracy by applying to other Landsat image for re-verification of study result.

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Change of Surface Temperature in Woodceramics Made from MDF(II) - Effect of Impregnation Rate and Burning Temperature - (MDF로 제조된 우드세라믹의 표면온도 변화(II) - 수지 함침율과 소성온도의 영향 -)

  • Oh, Seung Won;Byeon, Hee Seop
    • Journal of the Korean Wood Science and Technology
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    • v.31 no.1
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    • pp.41-45
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    • 2003
  • In this study, woodceramics were made from MDF with various resin impregnation rate. To investigate the change of surface temperature of woodceramics, the impregnated MDF was burned at the temp. 600, 800, 1,000, 1,200℃. Surface temperature of woodceramics was increased as impregnation rate and burning temperature was increased. The specimen burned at 800℃ was lower than others. Change of temperature under given temperature increased as time passed and it showed more increased in temperature at burning temperature of 1,200℃. Change of surface temperature increased when floor temperature increased and the temperature was 49.2℃ at 70℃ in floor temperature of 1,200℃ specimen. The decent in surface temperature of woodceramics was the fastest decrease at the burning temperature of 800℃ specimen.

Ground Surface Temperature Distribution of Korea (우리나라 지표면 온도 분포)

  • Koo, Min-Ho;Song, Yoon-Ho
    • 한국신재생에너지학회:학술대회논문집
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    • 2006.06a
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    • pp.431-433
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    • 2006
  • Accurate information on the ground surface temperature is essential for design of a borehole heat exchanger and thus ensuring the performance of a ground source heat pump system along with knowledge on thermal diffusivity and conductivity of ground. In this study we analyzed the shallow subsurface temperature monitoring data of 58 Korea Meteorological Administration synoptic stations. As a result, we compiled mean annual ground surface temperature distribution map using multiple regression analysis of the monitoring data.

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Effects of Thermal Properties and Water Retention Characteristics of Permeable Concrete Pavement on Surface Temperature (투.보수성 시멘트 콘크리트 포장의 열물성 및 수분보유특성이 표면온도에 미치는 영향)

  • Ryu Nam-Hyang;Yoo Byung-Rim
    • Journal of the Korean Institute of Landscape Architecture
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    • v.34 no.1 s.114
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    • pp.21-36
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    • 2006
  • This study was undertaken to analyze the effects of pavement thermal properties and water retention characteristics on the surface temperature of the gray permeable cement concrete pavement during the summer. Following is a summary of major results. 1) The hourly surface temperature of pavement could be well predicted with a heat transfer model program that incorporated the input data of major meteorological variables including solar radiation, atmospheric temperature, dew point, wind velocity, cloudiness and the evaporation rate of the pavements predicted by the time domain reflectometry (TDR) method. 2) When the albedo was changed to 0.5 from an arbitrary starting condition of 0.3, holding other variables constant, the peak surface temperature of the pavement dropped by 11.5%. When heat capacity was changed to $2.5\;kJm^{-3}K^{-1}\;from\;1.5\;kJm^{-3}K^{-1}$, surface temperature dropped by 8.0%. When daily evaporation was changed to 1 mm from 2 mm, temperature dropped by 5.7%. When heat conductivity was changed to $2.5\;Wm^{-1}K^{-1}\;from\;1.5\;Wm^{-1}K^{-1}$, the peak surface temperature of the pavement fell by 1.2%. The peak pavement surface temperature under the arbitrary basic condition was $24.46^{\circ}C$ (12 a.m.). 3) It accordingly became evident that the pavement surface temperature can be most effectively lowered by using materials with a high albedo, a high heat capacity or a high evaporation at the pavement surface. The glare situation, however, is intensified by raising of the albedo, moreover if reflected light is absorbed into surrounding physical masses, it is changed into heat. It accordingly became evident that raising the heat capacity and the evaporative capacity may be the moot acceptable measures to improve the thermal characteristics of the pavement. 4) The sensitivity of the surface temperature to major meteorological variables was as follows. When the daily average temperature changed to $0^{\circ}C\;from\;15^{\circ}C$, holding all other variables constant, the peak surface temperature of the pavement decreased by 56.1 %. When the global solar radiation changed to $200\;Wm^{-2}\;from\;600\;Wm^{-2}$, the temperature of the pavement decreased by 23.4%. When the wind velocity changed to $8\;ms^{-1}\;from\;4\;ms^{-1}$, the temperature decreased by 1.4%. When the cloudiness level changed to 1.0 from 0.5, the peak surface temperature decreased by 0.7%. The peak pavement surface temperature under the arbitrary basic conditions was $24.46^{\circ}C$ (12 a.m.)

A Study on the Responsibility of Thin film instantaneous surface temperature probe of a Dual-pipe structure (이중관 구조 박막형 순간온도 프로브의 응답성에 관한 연구)

  • Choi, Seok-Ryeol;Park, Kyoung-Suk
    • 한국연소학회:학술대회논문집
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    • 2003.12a
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    • pp.237-242
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    • 2003
  • The measurement study of instantaneous temperature at combustion chamber wall and the temperature of combustion gas has been under lots of research and development to conclude the temperature process in internal combustion engine for combustion characteristics analysis. The measurement with fast responsibility should be used for temperature measurement inside combustion chamber wall since temperature of wall changes, due to the various gas temperature, irregularly during the combustion. Therefore, thin film instantaneous surface temperature probe, which characterizes the fastest and the most accurate responsibility among contact typed temperature measurement, was used for the experiments. This new thin film instantaneous surface temperature probe improved the problems of noise and durability. The optimal coating thickness of thin film instantaneous surface temperature probe was proven to be $10{\mu}m$ for the best responsibility and durability. It also allowed the stable temperature measurement be taken up to $1,200^{\circ}C$ and proven to be read possibly from the combustion chamber wall.

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