• Title/Summary/Keyword: temperature estimation

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Comparison of Land Surface Temperatures Derived from Surface Emissivity with Urban Heat Island Effect (지표 방사율에 의한 지표온도와 도시열섬효과 비교)

  • Jeong, Jong-Chul
    • Journal of Environmental Impact Assessment
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    • v.18 no.4
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    • pp.219-227
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    • 2009
  • Because of urban development and changed land cover types, It is very important to acquire pixel unit of land surface temperature(LST) information when the heat island effect(HIE) of regional area are investigated. The brightness temperature observed by satellite is very useful for assessing the pixel unit of LST distributions for the analysis of thermal environment problems of urban areas. Also, satellite land cover data are very useful to our understanding of surface conditions of study areas. In this study, brightness temperature information of Landsat TM thermal channel was analyzed and compared with land cover information of Jeon-ju city. The atmospheric correction of TM thermal channel carried out to explain for compared LST long term monitoring errors. However, simple estimation and evaluation methods to find a physical relationship between LST from satellite images and in-situ data are compared with reference channel emissivity.

Estimation of Sea Surface Temperature Change by Tide Embankment Construction

  • Shin Dong-hoon;Lee Kyoo-seock
    • Proceedings of the KSRS Conference
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    • 2005.10a
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    • pp.146-148
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    • 2005
  • This study investigates to detect sea surface temperature (SST) and land cover change after tide embankment construction using Landsat Thematic Mapper (TM) thermal infrared (TIR) band data at Shihwa Lake and surrounding area. SST measurement is important for studies of both the structure of the ocean and as the thermal boundary between the ocean and the atmosphere. The TIR band of TM images can be used to detect SST change whose shoreline is complicated and narrow like the study site. The purpose of this study is to estimate SST and land cover change at Shihwa Lake and surrounding area.

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Longitudinal Displacement Analysis for Express Railway PSC Box-Girder Bridges (고속철도 PSC 박스거더의 종방향 신축변위 장기거동분석)

  • Yim Myoung-Jae;Choi Il-Yoon;Lee Jun S.;Lee Hyun-Suk
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.1102-1107
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    • 2004
  • High-speed railway bridges subject to effect of statical loads by temperature change as well as dynamic loads by interaction between vehicle load which run specially fast and behavior of bridges, If suitable longitudinal expansion by temperature change of bridge does not happened, it can cause unhealthy condition for the parts of bridges as well as can generate addition stress to bridges, For these reason, Analysis and Estimation of data about behavior of bridges occupies important factor in that estimate the remaining life of bridges and select the maintenance, repair and retrofit. In this paper, Analysis for the long-term behavior of bridges using Longitudinal displacement and Temperature data that is actuality measured data to the bridges of Seoul-Busan high speed railroad test section has been made.

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A Study on Improvement of Flow Characteristics for Thin-Wall Injection Molding by Rapid Mold Heating (급속 금형가열에 의한 박육 사출성형의 유동특성 개선에 관한 연구)

  • Park Keun;Kim Byung H.
    • Transactions of Materials Processing
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    • v.15 no.1 s.82
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    • pp.15-20
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    • 2006
  • The rapid thermal response (RTR) molding is a novel process developed to raise the temperature of mold surface rapidly to the polymer melt temperature prior to the injection stage and then cool rapidly to the ejection temperature. The resulting filling process is achieved inside a hot mold cavity by prohibiting formation of frozen layer so as to enable thin wall injection molding without filling difficulty. The present work covers flow simulation of thin wall injection molding using the RTR molding process. In order to take into account the effects of thermal boundary conditions of the RTR mold, coupled analysis with transient heat transfer simulation is suggested and compared with conventional isothermal analysis. The proposed coupled simulation approach based on solid elements provides reliable thin wall flow estimation for both the conventional molding and the RTR molding processes.

Development of the Soil Thermal Property and Temperature Measurement System for the Real-time Ampacity Estimation of Underground Power Cables (실시간 지중 전력케이블 용량 평가를 위한 토양 열 특성 및 온도 측정 시스템 개발)

  • Jeong, Seong-Hwan;Kim, Dae-Kyeong;Choi, Sang-Bong
    • Proceedings of the KIEE Conference
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    • 2002.07a
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    • pp.22-24
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    • 2002
  • This paper introduces the real-time soil thermal property analyzer and temperature measuring system which is combined with radio telecommunication technique. To measure the thermal parameters in real-time, the radio telecommunication technique are used the personal communication service (PCS) which is in the world-wide serviced commercially firstly by CDMA. The thermal property analyzer has an ability of measuring thermal resistivity, thermal diffusivity and thermal stability. To estimate the soil thermal properties, the curve fitting algorithm by means of the least square method are used. TCP/IP protocol and MTM are used to install the real-time soil thermal property and temperature measurement system at multiple locations along routes of the underground power cables and to reduce the cost of telecommunication.

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Estimation of the Heat Budget Parameter in the Atmospheric Boundary Layer considering the Characteristics of Soil Surface (지표면의 특성을 고려한 대기경계층내의 열수지 parameter 추정 -열수지 parameter를 이용한 중규모 순환의 수치예측-)

  • 이화운;정유근
    • Journal of Environmental Science International
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    • v.5 no.6
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    • pp.727-738
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    • 1996
  • An one dimensional atmosphere-canopy-soil interaction model is developed to estimate of the heat budget parameter in the atmospheric boundary layer. The canopy model is composed of the three balance equations of energy, temperature, moisture at ground surface and canopy layer with three independent variables of Tf(foliage temperature), Tg(ground temperature), and qg(ground specific humidity). The model was verilied by comparative study with OSUID(Oregon State University One Dimensional Model) proved in HAPEX-MOBILHY experiment. Also we applied this model in two dimensional land-sea breeze circulation. According to the results of this study, surface characteristics considering canopy acted importantly upon the simulation of meso-scale circulation. The factors which used in the numerical experiment are as follows ; the change for a sort of soil(sand and peat), the change for shielding factor, and the change for a kind of vegetation.

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Estimation of diffusion coefficient at the interface between liquid and vapor phases using the equilibrium molecular dynamics simulation (분자 동역학 모사를 이용한 액상과 기상 계면에서의 확산계수의 예측)

  • Kim, Kyeong-Yun;Choi, Young-Ki;Kwon, Oh-Myoung;Park, Seung-Ho;Lee, Joon-Sik
    • Proceedings of the KSME Conference
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    • 2003.04a
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    • pp.1584-1589
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    • 2003
  • This work applies the equilibrium molecular dynamics simulation method to study a Lennard-Jones liquid thin film suspended in the vapor and calculates diffusion coefficients by Green-Kubo equation derived from Einstein relationship. As a preliminary test, the diffusion coefficients of the pure argon fluid are calculated by equilibrium molecular dynamics simulation. It is found that the diffusion coefficients increase with decreasing the density and increasing the temperature. When both argon liquid and vapor phases are present, the effects of the system temperature on the diffusion coefficient are investigated. It can be seen that the diffusion coefficient significantly increases with the temperature of the system.

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A Estimation of Grinding-Processing by Slotted Wheel (슬롯형 숫돌에 의한 연삭가공성 평가)

  • 강신엽;왕덕현;이윤경
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 1997.04a
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    • pp.832-836
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    • 1997
  • An experimental study on the grinding temperature, surface roughness and Acoustic Emission(AE) signal was conducted with different shapes of wheel. The grinding characteristics by slotted shapes of wheel changed by width and helical angle,were compared with those by general one. Lower grinding temperature was obtained for 30 .deg. helical angel with 10mm width and Root Mean Square(RMS) values of AE signals were lower for slotted shapes rather than general one. Surface roughness characteristic of slotted shapes found to be rough,but the value of roughness for 45 .deg. helical angel with 6mm width, represented to similar tendency general one.

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Genetic Programming Based Compensation Technique for Short-range Temperature Prediction (유전 프로그래밍 기반 단기 기온 예보의 보정 기법)

  • Hyeon, Byeong-Yong;Hyun, Soo-Hwan;Lee, Yong-Hee;Seo, Ki-Sung
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.61 no.11
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    • pp.1682-1688
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    • 2012
  • This paper introduces a GP(Genetic Programming) based robust technique for temperature compensation in short-range prediction. Development of an efficient MOS(Model Output Statistics) is necessary to correct systematic errors of the model, because forecast models do not reliably determine weather conditions. Most of MOS use a linear regression to compensate a prediction model, therefore it is hard to manage an irregular nature of prediction. In order to solve the problem, a nonlinear and symbolic regression method using GP is suggested. The purpose of this study is to evaluate the accuracy of the estimation by a GP based nonlinear MOS for 3 days temperatures in Korean regions. This method is then compared to the UM model and has shown superior results. The training period of 2007-2009 summer is used, and the data of 2010 summer is adopted for verification.

Lifetime Estimation of Amplifier IC due to Electromigration failure (Electromigration 고장에 의한 Amplifier IC의 수명 예측)

  • Lee, Ho-Young;Chang, Mi-Soon;Kwack, Kae-Dal
    • Proceedings of the KSME Conference
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    • 2008.11a
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    • pp.1265-1270
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    • 2008
  • Electromigration is a one of a critical failure mechanism in microelectronic devices. Minimizing the thin film interconnections in microelectronic devices make high current densities at electrrical line. Under high current densities, an electromigration becomes critical problems in a microelectronic device. This phenomena under DC conditions was investigated with high temperature. The current density of 1.5MA/cm2 was stressed in interconnections under DC condition, and temperature condition $150^{\circ}C,\;175^{\circ}C,\;200^{\circ}C$. By increasing of thin film interconections, microelectronic devices durability is decreased and it gets more restriction by temperature. Electromigration makes electronic open by void induced, and hillock induced makes electronic short state.

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