• Korean Journal of Remote Sensing
• /
• v.35 no.4
• /
• pp.609-616
• /
• 2019

Land surface temperature ($T_s$) is a critical variable for understanding the surface energy exchange between land and atmosphere. Using the data measured from micrometeorological flux towers, three types of $T_s$, obtained using a thermal-infrared radiometer (IRT), a net radiometer, and an equation for sensible heat flux, were compared. The $T_s$ estimated using the net radiometer was highly correlated with the $T_s$ obtained from the IRT. Both values acceptably fit the $T_s$ from the Terra/MODIS (Moderate Resolution Imaging Spectroradiometer)satellite. These results will enhance the measurement of land surface temperatures at various scales. Further, they are useful for understanding land surface energy partitioning to evaluate and develop land surface models and algorithms for satellite remote sensing products associated with surface thermal conditions.

• Journal of the Korean Solar Energy Society
• /
• v.36 no.2
• /
• pp.1-7
• /
• 2016

This study was experimentally performed to analyze the growth characteristics of a plant(wax tree or privet) using the surface temperature measured from thermal images captured using a thermal camera with water and cider. To do that, this study measured every each 12 hours the surface temperature and the stem temperature of leaves attached to the plant sample until the plants wilt on summer season in the laboratory room. From the experimental results, this study revealed that the temperature of front and back of the leaves is a little different due to the pore. The mean surface temperature of a leaf in cider is $0.52^{\circ}C$ higher than that of a leaf in water. The phenomena that the leaves of plants fall could be also demonstrated using the surface temperature. Before a leaf is falling from the tree, the temperature of the stem is lowered about $2^{\circ}C$ than those of other parts in a leaf. This result can be validated from previous result performed in University of Wisconsin.

• Horticultural Science & Technology
• /
• v.31 no.4
• /
• pp.503-511
• /
• 2013

The purpose of this study was to evaluate temperature reduction and heat budget of extensive modular green roof planted with Sedum sarmentosum and Zoysia japonica. Plant height and green coverage were measured as plant growth. Temperature, net radiation and evapotranspiration of concrete surface, green roof surface, in-soil and bottom were measured from August 2 to August 3, 2012 (48 hours). On 3 P.M., August 3, 2012, when air temperature was the highest ($34.6^{\circ}C$), concrete surface temperature was highest ($57.5^{\circ}C$), followed by surface temperature of Sedum sarmentosum ($40.1^{\circ}C$) and Zoysia japonica ($38.3^{\circ}C$), which proved temperature reduction effect of green roof. Temperature reduction effect of green roof was also shown inside green roof soil, and bottom of green roof. It was found that Zoysia japonica was more effective in temperature reduction than Sedum sarmentosum. Compared with the case of concrete surface, the highest temperature of green roof surface was observed approximately 2 hours delayed. Plant species, temperature and soil moisture were found to have impact on surface temperature reduction. Plant species, air temperature, soil moisture and green roof surface temperature were found to have impact on temperature reduction in green roof bottom. As results of heat budget analysis, sensible heat was highest on concrete surface and was found to be reduced by green roof. Latent heat flux of Zoysia japonica was higher than that of Sedum sarmentosum, which implied that Zoysia japonica was more effective to improve thermal environment for green roof than Sedum sarmentosum.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.19 no.2
• /
• pp.55-69
• /
• 2016

Significant efforts are being devoted in mitigating the urban heat island effect, and extensive green roofs are an option for mitigation. The purpose of this study was to compare the surface temperature, vegetation types, and plant species on an extensive green roof. Test beds were created in May 2015, and the surface temperature was monitored from June to August. The test beds comprised polyculture and monoculture. Polyculture was divided into three types, and monoculture comprised eight plant species. An extensive green roof is effective in reducing temperature by forming a shade and preventing sunlight from falling on the surface of buildings, which mitigates the urban heat island effect. Consequently, the surface temperature of the green roof and that of concrete during summer reduced from $17.8^{\circ}C$ to $7.3^{\circ}C$. The temperature reduction was greater on using polyculture than on using monoculture, but monocultures of Sedum takesimense, Hemerocallis dumortieri, Allium senescens, Aster yomena, Belamcanda chinensis, and Aster koraiensis also produced good results. The temperature reduction effects of Polygonatum odoratum var. pluriflorum f. variegatum, Phlox subulata, and Thymus quinquecostatus var. japonica were excellent compared with those of concrete but were less than those of other plant species. Careful attention is needed for the management of extensive green roofs. Studies on the plant species and types of extensive green roof should continue to mitigate the urban heat island effect.

• Journal of The Geomorphological Association of Korea
• /
• v.25 no.4
• /
• pp.89-101
• /
• 2018

In Mt. Halla, an arctic-alpine plant Diapensia lapponica var. obovata largely clings to rock surfaces. We observed the rock-surface temperatures of a rocky ridge on the summit area of the mountain from late April 2009 to early May 2010 in order to examine the diurnal and annual temperature variations and the thermal amplitude. We also investigated temperature regimes such as the frequency of freeze-thaw cycles and the temperature change, which might endanger the habitat through frost weathering. For comparison of slope aspects, temperature monitoring was carried out on the north and south faces of the same rocky ridge. The south face experiences the high daily maximum rock-surface temperatures and the high thermal amplitudes during the unfreezing season of May to November 2009. The temperature regimes are considered to exert physiological stress to the arctic-alpine plant. In addition, the south face shows the high frequency of freeze-thaw cycles during the seasonal freezing period of December 2009 to April 2010. This indicates that the south face is susceptible the exfoliation and granular disintegration of rock surfaces, which results in habitat destruction. As a consequence, the south face is believed to be less favorable for the establishment and growth of the arctic-alpine plant than the north face on the summit area of Mt. Halla.

• Journal of the Korean Society of Environmental Restoration Technology
• /
• v.8 no.6
• /
• pp.34-44
• /
• 2005

The objective of this study is to analyze the thermal properties of various green roof type. The experimental districts, have different soil thickness, soil type, the existence of module and the different kinds of vegetation, had installed. A measurement was conducted in Seoul University to investigate the thermal impacts of rooftop greening. The measurement point of temperature were 30, located in soil surface, middle of the soil layer, under the module, hard surface and soffit surface of each experimental district. The experimental investigation lasted from 6th August to 29th August, a total of 24 days. The results showed that green roof can contribute thermal benefits by soil and vegetation and reduce building energy consumption by a role of insulation. It's also better to make soil thickness over 20cm and various vegetation that should be more effective. The district installed only soil also could be effective for reducing the temperature of roof surface. Therefore, the increase of soil thickness and various vegetation could reduce more temperature of roof surface and building energy consumption. Also, it's helpful to reduce temperature that plant coverage rate be raised.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.58 no.4
• /
• pp.37-46
• /
• 2016

This study is to estimate COMS (Communication, Ocean and Meteorological Satellite) daily land surface temperature (LST) of Korea Peninsula from 15 minutes interval COMS LST (COMS LST-15) satellite data. Using daily observed LST data of Automated Agriculture Observing System (AAOS) 11 stations from January 2013 to May 2015, the COMS daily LST was compared and validated. For the representative time for daily mean LST value from COMS LST-15, the time of 23 : 45 and 0:00 showed minimum deviations with AAOS daily LST. The time zone from 23 : 45 to 1:15 and from 7 : 30 to 9 : 45 showed high determination coefficient (R2) of 0.88 and 0.90 respectively. The daily COMS LST by averaging COMS LST-15 of the day showed R2 of 0.83. From the 5 cases of results, the COMS daily LST could be extracted from the average LST by using 15 minutes data from 7 : 30 to 9 : 45.

• Journal of the Korean institute of surface engineering
• /
• v.55 no.6
• /
• pp.433-440
• /
• 2022

Environmental pollution caused by power plant exhaust gas is highlighted and eco-friendly regulations are being strengthened. However, due to the abundant reserves and low prices of coal, still the most used for power generation in the world. Therefore, flexible operation of coal-fired power plants to reduce emissions has become an inevitable option. However, lowering the output increases the possibility of acid dew point corrosion as the exhaust gas temperature decreases. The dew point corrosion occurs when condensable gases such as SO₃, HCl, NO₂ and H₂O cools below the saturation temperature. SO₃ is already well known to cause severe low- temperature corrosion in coal-fired power plants. Therefore, this study aims to prevent damage that may occur during operation by analyzing the dew point and corrosion resistance with exhaust gas temperature and sulfuric acid concentration of the power plant economizer tube.

• Journal of the Optical Society of Korea
• /
• v.20 no.6
• /
• pp.770-777
• /
• 2016

It has been a challenge for researchers to accurately measure high temperature creep strain online without damaging the mechanical properties of the pipe surface. To this end, a noncontact method for measuring high temperature strain of a main steam pipe based on digital image correlation was proposed, and a system for monitoring of high temperature strain was designed and developed. Wavelet thresholding was used for denoising measurement data. The sub-pixel displacement search algorithm with curved surface fitting was improved to increase measurement accuracy. A field test was carried out to investigate the designed monitoring system of high temperature strain. The measuring error was less than $0.4ppm/^{\circ}C$, which meets actual measurement requirements for engineering. Our findings provide a new way to monitor creep damage of the main steam pipe of a boiler of an ultra-supercritical power plant in service.

• Journal of The Korean Society of Agricultural Engineers
• /
• v.59 no.1
• /
• pp.11-20
• /
• 2017

This study is to estimate the spatial soil moisture using multiple linear regression model (MLRM) and 15 minutes interval Land Surface Temperature (LST) data of Communication, Ocean and Meteorological Satellite (COMS). For the modeling, the input data of COMS LST, Terra MODIS Normalized Difference Vegetation Index (NDVI), daily rainfall and sunshine hour were considered and prepared. Using the observed soil moisture data at 9 stations of Automated Agriculture Observing System (AAOS) from January 2013 to May 2015, the MLRMs were developed by twelve scenarios of input components combination. The model results showed that the correlation between observed and modelled soil moisture increased when using antecedent rainfalls before the soil moisture simulation day. In addition, the correlation increased more when the model coefficients were evaluated by seasonal base. This was from the reverse correlation between MODIS NDVI and soil moisture in spring and autumn season.