• 제목/요약/키워드: Korean surface temperature

검색결과 12,721건 처리시간 0.046초

A New Forest Fire Detection Algorithm using Outlier Detection Method on Regression Analysis between Surface temperature and NDVI

  • Huh, Yong;Byun, Young-Gi;Son, Jeong-Hoon;Yu, Ki-Yun;Kim, Yong-Il
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2006년도 Proceedings of ISRS 2006 PORSEC Volume II
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    • pp.574-577
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    • 2006
  • In this paper, we developed a forest fire detection algorithm which uses a regression function between NDVI and land surface temperature. Previous detection algorithms use the land surface temperature as a main factor to discriminate fire pixels from non-fire pixels. These algorithms assume that the surface temperatures of non-fire pixels are intrinsically analogous and obey Gaussian normal distribution, regardless of land surface types and conditions. And the temperature thresholds for detecting fire pixels are derived from the statistical distribution of non-fire pixels’ temperature using heuristic methods. This assumption makes the temperature distribution of non-fire pixels very diverse and sometimes slightly overlapped with that of fire pixel. So, sometimes there occur omission errors in the cases of small fires. To ease such problem somewhat, we separated non-fire pixels into each land cover type by clustering algorithm and calculated the residuals between the temperature of a pixel under examination whether fire pixel or not and estimated temperature of the pixel using the linear regression between surface temperature and NDVI. As a result, this algorithm could modify the temperature threshold considering land types and conditions and showed improved detection accuracy.

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온수온돌 난방시 바닥면의 중성온도 설정에 관한 연구 (Establishment of Optimum Floor Surface Temperature Floor in Ondol Heating System)

  • 공성훈
    • 한국주거학회논문집
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    • 제6권2호
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    • pp.51-55
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    • 1995
  • This study presents a real neutral floor surface temperature in floor panel heating system(Ondol). The Ondol heating system can keep the constant temperature. However, the actual temperature when a person sits on a floor can be different from the surface temparature of a floor it self. The contents of this study are as follows : 1) measuring the spatial distributions of thermal conditions 2) the thermal sensation vote of residents is taken in order to investigate the relation between thermal condition and human thermal sensation in sedentary condition 3) estimating the neutral floor surface temperatures by measuring floor surface temperatures.

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소나무로 제조된 우드세라믹의 표면온도변화 - 승온속도 및 최고온도에서 유지시간의 영향 - (A Changes in Surface Temperature of Woodceramics Made from Pinus densiflora S. et. Z. - Effect of Heating Rate and Keeping Time at Maximum Temperature -)

  • 오승원
    • Journal of the Korean Wood Science and Technology
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    • 제35권3호
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    • pp.22-28
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    • 2007
  • 소나무 간벌재로 톱밥보드를 만든 후 우드세라믹을 제조하여 승온속도 및 최고온도에서의 유지시간에 따른 우드세라믹의 표면온도의 변화를 조사하였다. 승온속도 $2^{\circ}C/min$와 유지시간 1시간의 조건으로 제조된 우드세라믹의 표면 온도가 가장 높았다. 히터의 표면 온도보다 우드세라믹의 표면온도의 하강 속도가 느려 우드세라믹이 오랜 시간 열을 유지하고 있음을 알 수 있었다.

도시지역의 토지피복유형이 지표면온도에 미치는 영향: 경기도 일산 신도시를 중심으로 (Effect of the Urban Land Cover Types on the Surface Temperature: Case Study of Ilsan New City)

  • 김현옥;염종민
    • 대한원격탐사학회지
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    • 제28권2호
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    • pp.203-214
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    • 2012
  • 콘크리트와 아스팔트가 상당 부분을 차지하는 도시의 물리적인 환경은 도시열섬효과를 일으키는 주요 원인이며, 일차적으로 토지이용 또는 토양피복에 따른 지표면온도의 상승으로 나타난다. 본 연구에서는 도시의 토지피복유형이 지표면온도에 미치는 영향을 공간해상도가 다른 MODIS, Landsat ETM+과 RapidEye 위성영상을 사용하여 비교 분석해 보았다. 연구대상지인 일산 신도시지역의 지표면온도는 토지 이용에 따라 뚜렷이 구분되는 패턴을 보여주었는데 건폐율이 높은 저층단독주택지구보다 건폐율이 낮고 녹지율이 높은 고층 아파트단지의 지표면온도가 현저히 낮게 나타났다. 토지피복유형과의 관계는 건물이나 도로 등 도시화지역의 면적이 증가할수록 기후존의 지표면온도가 증가하고, 식생과 수면, 그림자 지역의 면적이 늘어날수록 지표면온도는 떨어진다. NDVI와 지표면온도 사이에도 음의 선형상관관계가 나타나지만, 계절적 영향을 배제하기 어렵다는 단점이 있다.

도로 및 기상조건을 고려한 노면온도변화 패턴 추정 모형 개발 (Developing Models for Patterns of Road Surface Temperature Change using Road and Weather Conditions)

  • 김진국;양충헌;김승범;윤덕근;박재홍
    • 한국도로학회논문집
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    • 제20권2호
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    • pp.127-135
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    • 2018
  • PURPOSES : This study develops various models that can estimate the pattern of road surface temperature changes using machine learning methods. METHODS : Both a thermal mapping system and weather forecast information were employed in order to collect data for developing the models. In previous studies, the authors defined road surface temperature data as a response, while vehicular ambient temperature, air temperature, and humidity were considered as predictors. In this research, two additional factors-road type and weather forecasts-were considered for the estimation of the road surface temperature change pattern. Finally, a total of six models for estimating the pattern of road surface temperature changes were developed using the MATLAB program, which provides the classification learner as a machine learning tool. RESULTS : Model 5 was considered the most superior owing to its high accuracy. It was seen that the accuracy of the model could increase when weather forecasts (e.g., Sky Status) were applied. A comparison between Models 4 and 5 showed that the influence of humidity on road surface temperature changes is negligible. CONCLUSIONS : Even though Models 4, 5, and 6 demonstrated the same performance in terms of average absolute error (AAE), Model 5 can be considered the optimal one from the point of view of accuracy.

톱밥과 왕겨 혼합보드로 제조된 세라믹의 표면 온도 변화 - 수지함침율 및 탄화온도의 영향 - (A Change in Surface Temperature of Ceramics Made from Board Mixed with Sawdust and Rice Husk - Effect of Resin Impregnation Rate and Carbonization Temperature -)

  • 오승원;박희준
    • Journal of the Korean Wood Science and Technology
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    • 제38권1호
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    • pp.43-48
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    • 2010
  • 톱밥과 왕겨로 제조된 혼합보드로 세라믹을 제조한 후 수지함침율 및 소성온도에 따른 세라믹의 표면온도를 조사하였다. 경과시간 초기에 표면온도가 급상승 하였으며 수지함침율 60~70%와 소성온도 $1200^{\circ}C$로 제조된 세라믹의 표면온도가 가장 높았다. 히터의 표면온도보다 혼합세라믹의 표면온도 하강속도가 느려 혼합세라믹의 열 보존력이 높음을 알 수 있었다.

온도가 세척계의 표면장력에 미치는 영향(제1보) -세액의 표면장력 성분변화를 중심으로- (Effect of Temperature on the Surface Tensions in the Detergency System(I) -Change of Surface Tension Components of Washing Liquids-)

  • 채정희;김성련
    • 한국의류학회지
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    • 제17권4호
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    • pp.511-517
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    • 1993
  • Changes of the surface and interface tension with temperature for washing liquids and alkanes were measured by FACE surface tensiometer. Using the extended Fowkes' equation, the dispersion and polar force components of the surface tension were estimated. The results were as follows : 1. The surface tensions of washing liquids and alkanes decreased almost linearly with the increase of temperature. 2. The interface tensions of 0.25% DBS/alkane increased slowly with the increase of temperature. In the case of nonionic surfactant solutions, however, the interface tensions with alkanes varied with the number of hydrophilic ethylene oxide(EO) groups. 3. Of the surface tension of water at $20^{\circ}C$, the dispersion force component was 25.3 dyn/cm and the polar force component was 47.8 dyn/cm. As the temperature increased, both the polar and dispersion force components decreased in a similar fashion. 4. The dispersion force component of surface tension of 0.25% DBS solution was 30.0 dyn/cm, and the polar force component was 2.2 dyn/cm at $20^{\circ}C$. The two components decreased with the increase of temperature. 5. As the temperature increased, the dispersion force component of surface tension decreased and the polar force component increased significantly for 0.25% NPPG-7.5EO solution. In the case of 025% NPPG-10EO, both the dispersion and polar force components decreased slowly, but the polar force component is expected to increase from $60^{\circ}C$. However, the polar force component of surface tension decreased with the increase of temperature for 025% NPPG-15EO solution, and at the temperature higher than $60^{\circ}C$ the surface tension is expected to be composed of only dispersion force component.

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SPECTRAL LINE-DEPTH RATIO AS A PRECISE EFFECTIVE TEMPERATURE AND SURFACE GRAVITY INDICATOR FOR WARM STARS

  • Kim, Chul-Hee
    • 천문학회지
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    • 제39권4호
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    • pp.125-128
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    • 2006
  • In order to determine the precise effective temperature and surface gravity of warm stars, all synthetic spectral lines in the wavelength range of $4000-5700{\AA}$ with T=6000-7750 K, and log g=3.5, 4.0, and 4.5 for [M/H]=0.0, $V_{rot}$=10 km $s^{-1}$, and $V_{tubl}$=2 km $s^{-1}$ were calculated using the SYNSPEC package(Hubeny, et al., 1995) and the Kurucz(1995) model. Then, the depth-ratios for all line pairs were investigated and we selected two and six depth-ratios appropriate for the surface gravity and temperature indicators, respectively. We plotted six grids with X- and Y-axes for the depth-ratios of surface gravity and temperature, respectively, for the simultaneous estimation of these two atmospheric parameters. This method was applied to the spectum of $\delta$ Scu for the determination of its temperature and surface gravity simultaneously.

손목 피부 온도에 의한 맥센서 어레이(array)의 신호 변동 및 보정 (Signal Change and Compensation of Pulse Pressure Sensor Array Due to Wrist Surface Temperature)

  • 전민호;전영주;김영민
    • 센서학회지
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    • 제26권2호
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    • pp.141-147
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    • 2017
  • A pressure sensor in pulse measurement system is a core component for precisely measuring the pulse waveform of radial artery. A pulse sensor signal that measures the pulse wave in contact with the skin is affected by the temperature difference between the ambient temperature and skin surface. In this study, we found experimentally that the signal changes of the pressure sensors and a temperature sensor were caused by the temperature of the wrist surface while the pressure sensor was contacted on the skin surface for measuring pulse wave. To observe the signal change of the pulse sensor caused by temperature increase on sensor surface, Peltier device that can be kept at a set temperature was used. As the temperature of Peltier device was kept at $35^{\circ}C$ (the maximum wrist temperature), the device was put on the pulse sensor surface. The temperature and pressure signals were obtained simultaneously from a temperature sensor and six pressure sensors embedded in the pulse sensor. As a result of signal analysis, the sensor pressure was decreased during temperature increase of pulse sensor surface. In addition, the signal difference ratio of pressure and temperature sensors with respect to thickness of cover layer in pulse sensor was increased exponentially. Therefore, the signal of pressure sensor was modified by the compensation equation derived by the temperature sensor signal. We suggested that the thickness of cover layer in pulse sensor should be designed considering the skin surface temperature.

MODIS 자료를 이용한 한반도 지표면 온도산출 알고리즘의 비교 연구 (Comparison Study on the Estimation Algorithm of Land Surface Temperature for MODIS Data at the Korean Peninsula)

  • 이순환;안지숙;김해동;황수진
    • 한국환경과학회지
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    • 제18권4호
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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.