• Title/Summary/Keyword: Korean surface temperature

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Analyzing the correlation between urban forestry and surface temperature using Landsat TM data

  • Jo, Myung-Hee;Kim, Sung-Jae;Lee, Kwang-Jae
    • Proceedings of the KSRS Conference
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    • 2003.11a
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    • pp.905-907
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    • 2003
  • In this study, the correlation between the heat island effect and the vegetation in Deagu Korea was performed through using Landsat TM data. the island effect, presents high temperature on air like island, is connected with correlation between the surface temperature and the temperature on the air. In this study, surface temperature was analyzed by detecting the change of urban forestry with remote sensing using the vegetation vitality statistics reference (ratio change of the Park greens in Daegu) the heat island effect not only brings the environment pollution but also brings serious problem such as the destruction of ecosystem to city as a whole. Jeff Luvall has studied to restrain the heat island effect by making urban forestry. Even though Daegu had been the serious high temperature urban area the current temperature of Daegu has been dropped. The correlation between the heat island effect and the vegetation index was analyzed by using satellite images.

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Statistical Atmospheric Correction of Lake Surface Temperature from Landsat Thermal Images

  • Han, Hyang-Sun;Lee, Hoon-Yol
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.418-421
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    • 2005
  • In this study, we analyzed surface temperature of lakes in the Han River system, using Landsat-5 and -7 time-series images. Surface temperature was extracted using NASA equation and compared with in situ 10m-depth temperature in Lake Soyang and surface temperature on five other dam lakes downstream. The 24 images out of 29 showed standard deviation of temperature difference less than $2^{\circ}C$, to which a novel statistical atmospheric correction could be applied. The correlation coefficients were 0.950 at Lake Soyang and 0.979-0.997 at the other lakes after atmospheric correction.

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An Experimental Study on Low-Temperature Behavior of Stratified Fluids in a Square Cavity with Upper Cooling Surface (상부에 냉각면이 있는 정방형내 이종유체의 저온거동에 관한 실험적 연구)

  • Lee, D.S.;Kim, B.C.
    • Solar Energy
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    • v.20 no.1
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    • pp.55-62
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    • 2000
  • An experimental study on the stratified fluids with water and silicon oil of same volume in the cavity with upper cooling surface was carried out to investigate the flow characteristics, heat transfer through the interface of fluids, and the applications of thermal behaviors in a square cavity. The experiments were performed with variation of initial temperature and cooling surface temperature. The temperature drop of oil was faster than that of water and freezing was initiated from the interface of oil and water and propagated downward. For the water above $4^{\circ}C$, the cooling rate was faster than that below $4^{\circ}C$ and showed almost same temperature distribution but for the water that of below $4^{\circ}C$, it showed the stable stratified temperature distribution. The lower the initial temperature and the higher the cooling surface temperature was, the longer the supercooling duration.

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The Change of Clothing Insulation and Surface Temperature Measured by Thermography with the Ease of Pattern (의복의 여유분에 따른 단열력의 변화와 Thermogram을 활용한 의복 표면 온도 특성 분석)

  • Lee, Byung-Cheol;Hong, Kyung-Hi;Lee, Ye-Jin
    • Korean Journal of Human Ecology
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    • v.19 no.6
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    • pp.1045-1052
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    • 2010
  • Effects of the ease of pattern on the thermal conditions of clothing were investigated through the measurement of clothing surface temperatures using infrared thermography. Four vests with different pattern ease were worn by five male subjects. Surface temperature distribution on the clothing were then examined using a thermogram to view thermo-regulating characteristics affected by the ease of pattern. Representative surface temperatures were calculated based on the percentage of the surface area within a certain temperature range and the midpoint value of the corresponding area. Representative surface temperatures matches well to the thermal insulation value measured by thermal manikin. Results indicated that representative surface temperature could be a useful quantitative value if some simple calculations were to be used alongside accurate image processing.

The Joining Quality of High Strength Bolt, Nut and Washer Set (S10T & 10.9HRC) under the Surface Treatment Conditions (표면처리별 S10T, 10.9HRC 고장력 볼트 세트의 체결 품질 연구)

  • Choi, Youn-O;Suk, Han-Gil;Hong, Hyeon-Sun
    • Journal of the Korean institute of surface engineering
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    • v.48 no.3
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    • pp.93-99
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    • 2015
  • This test focuses on the correlations between joining axial force at non-room temperature and at room temperature according to the surface treatment (Geomet, Dacro, Green Kote, Armore Galv.). The quality characteristics of the fastening axial force required by the KSB 2819 and EN14399-10 standards were discussed. Surface treatment was implemented to S10T and 10.9HRC sets of bolts under the same environmental factors. Development for the stabilization of the fastening axial force required by each standard should continually be enforced, and the fastening and storage in the field should be maintained at room temperature. Managing stabilization of torque enumerated data is required after application of surface treatment. It is concluded that, by conducting the test of applying surface treatment to effectively manage, each lot-specific rate of axial force at room temperature conditions should be maintained below the maximum 4.47%. The decline rate of axial force should be maintained under 2.15% maximum, and the standard deviation of the room temperature condition should be maintained below 0.5.

Development of Precise Measuring System for Hot Strip Mill's Rolls (열간압연용 롤 정밀 측정시스템 개발)

  • 이성진;이영진
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 2002.04a
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    • pp.614-618
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    • 2002
  • In hot strip mills, Portable Roll Scanner (the portable roll surface temperature and profile measuring device) can be used to calibrate on-line Process models for strip crown and flatness by measuring the thermal expansion and wear profile of the rolls. And the surface temperature measurement can be used to optimize the roll cooling system. Portable Roll Scanner consists of the measuring device, which has two contact inductive distance transducers for roll profile measurement and one infrared Pyrometer for surface temperature measurement, and computer-based controller that is equipped with the measuring device. By the wireless data communication, the data is transferred to the memory of notebook for further analysis. After roll extraction from mills, Portable Roll Scanner measure the roll profile and surface temperature simultaneously along the work roll face and display the results in the TFT color monitor of notebook. Portable Roll Scanner is useful at mill-side and roll grinding shop.

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Electrical Properties of Woodceramics with Sending an Electric Current (통전한 우드세라믹의 전기적 성질)

  • Oh, Seung Won
    • Journal of the Korean Wood Science and Technology
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    • v.35 no.4
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    • pp.9-13
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    • 2007
  • Using sawdust boards made of pine by differing the percentage of resin impregnation, wood-ceramics were manufactured by carbonizing temperature at $650^{\circ}C$. Their electrical properties and surface temperature were measured by sending an electric current. As electrical resistance of woodceramic was lower, its surface temperature, even in a low voltage, became higher. It seemed to be necessary to applying higher voltage to the woodceramic to raise the surface temperature by target temperature $70^{\circ}C$ or more in this study, according as resistance increased. When the voltage increased, woodceramics showed higher level all in electric current, electric power and surface temperature. Arrival time, electric current and electric power increased with increase of target temperature under constant voltage.

A Study on Scoring Resistance In Lubricated Sliding Contact (윤활 마찰면의 스코링 저항성에 관한 연구)

  • 김해원;홍재학;허준영
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.14 no.2
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    • pp.358-366
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    • 1990
  • As a basic study to clarify the scoring resistance in lubricated sliding contact, the temperature rise on frictional surface was analyzed by theoretical method and the effects of various factors on the temperature rise were examined. On the basic of the results obtained theoretically, the practical equations to calculate the maximum average temperature of the contact surface were proposed which are applicable to sliding contact. Then, the effects of sliding velocity and oil temperature on the seizure behavior, and the relation between seizure and temperature rise were investigated. The following conclusions are deduced : The maximum average temperature rise and the other bulk temperature. The former is affected by the size of heat supply region and the sliding velocity, the latter is affected by heat transfer coefficient. Without regard to the operating condition such as sliding velocity, oil temperature and operating time at each load-step, the maximum average temperature just before seizure is nearly constant except in the region of lower velocity. Consequently, the maximum average temperature of the contact surface in boundary lubrication is a useful criterion to predict the scoring of sliding contact.

SWR as Tool for Determination of the Surface Magnetic Anisotropy Energy Constant

  • Maksymowicz, L.J.;Lubecka, M.;Jablonski, R.
    • Journal of Magnetics
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    • v.3 no.4
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    • pp.105-111
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    • 1998
  • The low energy excitations of spin waves (SWR) in thin films can be used for determination of the surface anisotropy constant and the nonhomogeneities of magnetization in the close-to-surface layer. The dispersion relation in SWR is sensitive on the geometry of experiment. We report on temperature dependence of surface magnetic anisotropy energy constant in magnetic semiconductor thin films of$ CdCr_{2-2x}In_{2x}Se_4$ at spin glass state. Samples were deposited by rf sputtering technique on Corning glass substrate in controlled temperature conditions. Coexistence of the infinite ferromagnetic network (IFN) and finite spin slusters (FSC) in spin glass state (SG) is know phenomena. Some behavior typical for long range magnetic ordering is expected in samples at SG state. The spin wave resonance experiment (microwave spectrometer at X-band) with excited surface modes was applied to describe the energy state of surface spins. We determined the surface magnetic anisotropy energy constant versus temperature using the surface inhomogeneities model of magnetic thin films. It was found that two components contribute to the surface magnetic anisotropy energy. One originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the originates from the exchange interaction term due to the lack of translation symmetry for surface spin as well as from the stray field of the surface roughness. The second one comes from the demagnetizing field of close-to surface layer with grad M. Both term linearly decrease when temperature is increased from 5 to 123 K, but dominant contribution is from the first component.

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Surface Treatment with CO2 to Improve Electrochemical Characteristics of Carbon Felt Electrode for VRFB

  • Yechan Park;Sunhoe Kim
    • Journal of Electrochemical Science and Technology
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    • v.14 no.2
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    • pp.131-138
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    • 2023
  • The carbon felt is usually hired as electrodes for vanadium redox flow battery (VRFB). In the study, surface modification of carbon felt under CO2 atmosphere with variables of operating various temperature ranges between 700℃ and 900℃. The qualitative and quantitative analysis were carried out such as scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS) to observe degree of surface modification. Result of XPS analysis confirmed increase of carbon and oxidation functional group on the surface with increase of temperature. SEM image was discovered similar phenomena. Electrochemical characteristics such as cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) revealed the improved electrode performance with increase of temperature. However, the electrochemical performance under treatments temperature of 900℃ was less than that of under treatment temperature of 850℃ due to weight loss at the treatment temperature of 900℃. From the CV and EIS results, the best electrochemical characteristics was at the temperature of 850℃. That of at the temperature of 900℃ was decreased due to weight loss. The energy efficiencies (EE) obtained from full cell test were 69.37, 80.76, 82.45, and 75.47%, at the temperature of 700, 800, 850, and 900℃, respectively.