• Journal of Environmental Science International
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• v.18 no.4
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• pp.355-367
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• 2009

Comparison study on the land surface temperatures, which are calculated from four different algorithms for MODIS data, was carried out and the characteristics of each algorithm on land surface temperature estimation were also analysed in this study. Algorithms, which are well used for various satellite data analysis, in the comparisons are proposed by Price, Becker and Li, Ulivieri et al., and Wan. Verification of estimated land surface temperature from each algorithm is also performed using observation based regression data. The coefficient of determination ($R^2$) for daytime land surface temperature estimated from Wan's algorithm is higher than that of another algorithms at all seasons and the value of $R^2$ reach on 0.92 at spring. Although $R^2$ for Ulivieri's algorithm is slightly lower than that for Wan's algorithm, the variation pattern of land surface temperature for two algorithms are similar. However, the difference of estimated values among four algorithms become small at the region of high land surface temperature.

• Proceedings of the KSME Conference
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• 2004.04a
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• pp.1243-1249
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• 2004

This study is focused on the comparison between the internal saturation temperature of the working fluid and the surface temperature of adiabatic zone of two-phase closed thermosyphons with various helical grooves. Distilled water, methanol and ethanol have been used as the working fluid. In the present work, a copper tube of the length of 1200mm and 14.28mm of inside diameter is used as the container of the thermosyphon. Each of the evaporator and the condenser section has a length of 550mm, while the remaining part of the thermosyphon tube is adiabatic section. A experimental study was carried out for analyzing the performances of having 50, 60, 70, 80, 90 helical grooves. A plain thermosyphon having the same inner and outer diameter as the grooved thermosyphons is also tested for the comparison. The results show that the numbers of grooves and the type of working fluids are very important factors for the operation of thermosyphons. A good agreement between the internal saturation temperature of working fluid and the surface temperature of adiabatic zone of two-phase closed thermosyphons with various helical grooves is obtained.

• 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.

• Journal of the Korean Vacuum Society
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• v.8 no.3A
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• pp.181-186
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• 1999

The diffusion of oxygen atoms on tungsten (110) surface is studied by comparison of experiment results and recent calculations. It has been suggested that the thermodynamic factor which is inversely proportional to be compressibility has strong temperature dependence which may cause non-Arrhenius behavior of diffusion coefficient. Recent experiments, however, indicate effectively no temperature dependence of this factor and support the view that non-Arrhenius behavior originates from the dynamic factor rather than the thermodynamic factor. Discrepancies in coverage dependence of physical quantities between theory and experiment are discussed.

• Journal of the Korean Society of Manufacturing Process Engineers
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• v.19 no.4
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• pp.9-15
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• 2020

Carbon fiber reinforced plastic (CFRP) is a composite material useful in the aerospace and automotive industries because of its light weight and high strength. In this study, side milling tests were carried out using AlCrN, diamond-like carbon (DLC), and diamond-coated end mills. Additionally, a comparison study according to the cobalt content was conducted. Thus, tool wear and surface quality were examined and the influences of using coating and a certain material type were analyzed. The surface roughness of the machined surface was measured. Microscope observations revealed that the CFRP fiber at the machined surface was not damaged even at a cutting distance of 3,000 mm. Therefore, this study showed that the diamond-coated end mill containing 6% cobalt is appropriate for milling CFRP.

• Journal of the Korean institute of surface engineering
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• v.29 no.5
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• pp.338-344
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• 1996

This study was an investigation of plasma-induced damages on silicon substrate in the semiconductor manufacturing technology. The plasma-induced damage level on silicon substrate was analyzed and compared in various plasma etching systems. The analysis methods were therma wave, life-time recovery, SCA (Surface Charge Analyzer) and TRXF (Total Reflection X-ray Fluorescence) measurements, and the measured values were compared for each systems. In the comparison of the values which were obtained by a system that had low life-time recovery, there was not any differences in DC parameters. However, the reflesh time distribution of device of that system had decreased about 10 to 20m sec compared to a system which had high life-time recovery.

• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2022.11a
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• pp.323-324
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• 2022

This paper explains the comparison results of surface current measurement using X-band Radar image through analysis. Measurements were carried out from February 2022 using the X-band Radar for marin ships installed at Sokcho Beach. Based on the Korea Hydrographic and Oceanographic Agency ocean observation buoys, the accuracy of surface current(current speed) measurement was verified through comparison and analysis of measurement data.

• Proceedings of the Korean Society of Fisheries Technology Conference
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• 1998.06a
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• pp.382.2-383
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• 1998

• Journal of The Korean Astronomical Society
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• v.13 no.1
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• pp.27-33
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• 1980

Surface density distributions for globular clusters were obtained from photoelectric surface photometry (using centered aperture photometry). These surface brightness profiles were then compared with the theoretical surface density distribution of King's model. From the comparison of the theoretical and observed surface density distributions, we determine he structural parameters of the clusters (the core radius $r_c$, the tidal cut off $r_t$, and the concentration factor C).

• Proceedings of the KSME Conference
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• 2001.06b
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• pp.65-69
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• 2001

In this study, the deformation of the free surface motion of a magnetic fluid for the change in electromagnetic force is discussed. In case, magnetic fluid in characteristics of fluid adjusted to the opposite direction of the gravity direction. Thus, the device of a magnetic fluid proposed the complete zero-leakage Sealing and the surface actuator. The device of surface deformation as well comparison between numerical simulation and experiments as will be presented.