• Journal of Korean Society on Water Environment
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• v.28 no.1
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• pp.137-147
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• 2012

Land surface temperature in ecohydrology is a variable that links surface structure to soil processes and yet its spatial prediction across landscapes with variable surface structure is poorly understood. And there are an insufficient number of soil temperature monitoring stations. In this study, a grid-based land surface temperature prediction model is proposed. Target sites are Andong and Namgang dam region. The proposed model is run in the following way. At first, geo-referenced site specific air temperatures are estimated using a kriging technique from data collected from 60 point weather stations. Then surface soil temperature is computed from the estimated geo-referenced site-specific air temperature and normalized difference vegetation index. After the model is calibrated with data collected from observed remote-sensed soil temperature, a soil temperature map is prepared based on the predictions of the model for each geo-referenced site. The daily and monthly simulated soil temperature shows that the proposed model is useful for reproducing observed soil temperature. Soil temperatures at 30 and 50 cm of soil depth are also well simulated.

• Proceedings of the KSME Conference
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• 2007.05b
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• pp.2512-2517
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• 2007

Effect of natural convention for hot plate surface temperature uniformity was studied by experiments that were adjusted height of chamber and temperature difference. The hot plate chamber is composed of the hot plate and the upper heater and adiabatic vertical wall. The hot plate diameter is 220mm and maintains temperature at $150^{\circ}C$. Flow pattern compares with surface temperature and confirms that natural convection affects on temperature uniformity of hot plate surface. In case, temperature non-uniformity of hot plate surface is due to heater pattern, lots of weak and small flow cells more improve temperature uniformity than stronger flow cells or non-developing flow cell. Improve temperature uniformity $1.2^{\circ}C$ when developing weak and small flow cells.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.5
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• pp.359-364
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• 2013

This study was conducted to develop a model to estimate crop leaf surface temperature. The results were as following; A definition for the daily time based on elapsed time from the midnight (00:00) as "E&E time" with the unit of Kmin. was suggested. The model to estimate the scaled temperature ($T^*e$) of crop leaf surface temperature by scale factor ($T^*$) according to the "E&E time : Kmin."(X) was developed as eq. (1) $T^*e=0.5{\cdot}sin(X+780)+0.5$ (2) $T^*=(Tx-Tn)/(Tm-Tn)$, Tx : Daily leaf temperature, Tm : Daily maximum leaf temperature, Tn : Daily minimum leaf temperature. Relative sensitivity of the measured temperature compared to the estimated temperature of red pepper, soybean and persimmon was 1.078, 1.033 and 0.973, respectively.

• Journal of the Korean Society for Geothermal and Hydrothermal Energy
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• v.14 no.3
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• pp.8-14
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• 2018

PV module power is calculated on PV module surface temperature adjustment by irradiation on the summer and autumn in NOCT(Nominal Operating Cell Temperature) conditions. The summer and autumn periods were selected because of large variation in outdoor air temperature and irradiation. This study was performed to understand relationship between PV module surface temperature and photovoltaic power using field measurement. As a results, it was determined that the amount of irradiation was proportional to the amount of photovoltaic power in the field measurement. However, it was also identified that the PV power generation decreased by increased PV module surface temperatures due to irradiation.

• Tribology and Lubricants
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• v.23 no.2
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• pp.56-60
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• 2007

The main object of this study is to compare the results that have been concluded by the experiment and to estimate the temperature rise that can cause the contacting surface to be damaged. The former studies are based on the Blok and Jaeger formula. By these formulas we assume that two of the contacted objects are a kind of semi-infinite solid and with this assumption we can make a temperature analysis. But this method doesn't consider lubrication conditions and the calculation time requires a lot of time in that we have to face many difficulties in measuring the actual temperature rise. In this study we combines the semi-infinite solid method and the finite volume method to analyze the temperature of the contacting surface. And we measure temperature rise of the contact surface by dynamic thermocouple.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.442-444
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• 2006

On long time scale and over large areas ground surface temperatures (GSTs) track surface air temperatures (SATs). Additionally, GST changes penetrate into the subsurface and are recorded as transient temperature perturbation to the background thermal filed. Therefore, climate change can be reconstructed from borehole temperature measurements We present GST hi story reconstructed from temperature measurements in a borehole at Pocheon The result shows that GST cold period in the late 19th century and then increased by about 2K to 1990. GST history matches well with surface air temperatures measured from 1907 to 2001 at the Seoul Meteorological Station and GST history reconstructed from temperature measurements in three boreholes at Ulsan.

• Journal of Advanced Marine Engineering and Technology
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• v.25 no.2
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• pp.331-337
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• 2001

A numerical simulation of the temperature rise for sliding surface in dry contact is based on Jaegers formula combined with a calculated heat input. A gear tooth temperature analysis was performed. The pressure distribution has the Hertzian pressure distribution on the heat source. The heat partition factor is calculated along ling of action. A Temperature distribution of tooth surface is calculated about before and after profile modification. A Temperature of addendum and deddendum in modified gear have reduced.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.4
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• pp.11-16
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• 2015

Spatial and temporal information on near-surface air temperature is important for understanding global warming and climate change. In this study, the estimation algorithm of near-surface air temperature in Korea was developed by using spatial homogeneous surface information obtained from satellite remote sensing observations. Based on LST(Land Surface Temperature), NDWI(Normalized Difference Water Index) and NDVI(Normalized Difference Vegetation Index) as independent variables, the multiple regression model was proposed for the estimation of near-surface air temperature. The different regression constants and coefficients for warm and cold seasons were calculated for considering regional climate change in Korea. The near-surface air temperature values estimated from the multiple regression algorithm showed reasonable performance for both warm and cold seasons with respect to observed values (approximately $3^{\circ}C$ root mean-square error and nearly zero mean bias). Thus;the proposed algorithm using remotely sensed surface observations and the approach based on the classified warm and cold seasons may be useful for assessment of regional climate temperature in Korea.

• Wind and Structures
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• v.36 no.3
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• pp.201-213
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• 2023

In this study, the effect of sea surface temperature (SST) on the distribution of vertical wind speed in the atmospheric boundary layer of coastal areas was analyzed. In general, coastal areas are known to be more susceptible to various meteorological factors than inland areas due to interannual changes in sea surface temperature. Therefore, the purpose of this study is to analyze the relationship between sea surface temperature (ERA5) and wind resource data based on the meteorological mast of Høvsøre, the test bed area of the onshore wind farm in the coastal area of Denmark. In addition, the possibility of coastal disasters caused by abnormal vertical wind shear due to changes in sea surface temperature was also analyzed. According to the analysis of the correlation between the wind resource data at met mast and the sea surface temperature by ERA5, the wind speed from the sea and the vertical wind shear are stronger than from the inland, and are vulnerable to seasonal sea surface temperature fluctuations. In particular, the abnormal vertical wind shear, in which only the lower wind speed was strengthened and appeared in the form of a nose, mainly appeared in winter when the atmosphere was near-neutral or stable, and all occurred when the wind blows from the sea. This phenomenon usually occurred when there was a sudden change in sea surface temperature within a short period of time.

• Proceedings of the Korean Vacuum Society Conference
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• 2016.02a
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• pp.156.2-156.2
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• 2016

The variation of the surface structure of the Al adsorbed W(110) planes according to the coverage and the substrate temperature has been investigated using LEED and ISS When the Al atoms were adsorbed on the W(110) surface at room temperature, a p($1{\times}1$) of the fcc (111) face were found at the coverage higher than 4 ML. When the substrate temperature was kept at 900 K during Al adsorption and the coverage was 1.0 ML, the surface revealed a p($1{\times}1$) of the bcc(110) face and when the coverage is 1.5 ML, the surface showed a p($1{\times}1$) of the bcc (110) face together with a p($1{\times}1$) double domain structure (fcc (111) face) rotated ${\pm}3^{\circ}$ from the [100] direction of the W(110) surface. When Al atoms were adsorbed on the W(110) surface at the substrate temperature of 1000 K and the coverage was higher than 1.0 ML, the surface revealed a p($1{\times}1$) of the bcc(110) face together with p($1{\times}1$) double domain structure(fcc(111) face) rotated ${\pm}3^{\circ}{\sim}5^{\circ}$ from the [100] direction of the W(110) surface. When Al atoms were adsorbed on the W(110) surface at the substrate temperature of 1100 K and the coverage was 0.5 ML, Al atoms formed a p($2{\times}1$) double domain structure When the coverage was 1.0 ML, the double domain hexagonal structure (fcc(111) face) rotated ${\pm}5^{\circ}$ from the [100] direction of the W(110) surface and another distorted hexagonal structure was found. Low-energy electron diffraction results along with ion scattering spectroscopy results showed that the Al atoms followed the Volmer-Weber growth mode at high temperature.