• 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.

• 대한기계학회논문집
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• 제16권2호
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• pp.207-225
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• 1992

The study is concerned with the thermo-viscoplastic finite element analysis of axisymmetric forward hot extrusion through square dies. The problem is treated as a nonsteady state problem because the distribution of temperature and material properties are continuously changing with the punch travel. In square die extrusion, difficulties arise from the severe distortion and die interference of elements at the aperture rim of the die even with a small punch travel. And finite element computation is impossible without intermittent remeshing. Accordingly, an automatic remeshing technique is proposed by employing specially designed mesh structure near the aperture rim. The analysis of temperature distribution includes heat conduction through material interfaces, heat convection and radiation to the atmosphere and is carried out by decoupling the heat analysis from the analysis of the deformation. The extrusion load and the distributions of strain rate and temperature are computed for the given cases rendering reasonable results. Computed grid distortions are found to be in good agreement with the experimental results. It has been thus shown that the proposed method of analysis can be effectively applied to the axisymmetric hot extrusion through square dies.

• 한국전산구조공학회논문집
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• 제20권2호
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• pp.157-164
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• 2007

고준위폐기물을 지하 500m의 화강암 암반의 처분장에 장기간(약 10,000년 동안) 처분 시 폐기물에서 발생하는 열에 의하여 처분용기 및 처분용기를 감싸고 있는 주위 구조물(벤토나이트 버퍼, 암반 등)의 처분시간 경과에 따른 온포분포 변화를 알아내는 것은 처분장 설계를 위하여 매우 중요하다. 본 논문에서는 수치해석기법을 이용하여 고준위폐기물에서 발생하는 열에 의한 처분용기 및 벤토나이트 버퍼, 처분동굴을 포함하는 복합구조물의 온도분포 변화를 구하였다. 특히 처분 후 500년의 처분시간 경과에 따른 복합구조물의 온도분포 해석을 수행하여 온도분포 변화를 구하였다. 시간에 따른 온도분포 변화에 대한 해석결과를 분석한 결과 처분장 각 구성부분별로 차이는 있으나 처분초기부터 구성부분별로 각각 다르게 온도가 증가하는데 가장 늦은 부분은 150년까지 완만하게 온도가 증가하다가 그 이후에는 온도가 서서히 감소하는 것으로 나타났다.

• Steel and Composite Structures
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• 제22권4호
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• pp.889-913
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• 2016

Vibration analysis of embedded functionally graded (FG)-carbon nanotubes (CNT)-reinforced piezoelectric cylindrical shell subjected to uniform and non-uniform temperature distributions are presented. The structure is subjected to an applied voltage in thickness direction which operates in control of vibration behavior of system. The CNT reinforcement is either uniformly distributed or functionally graded (FG) along the thickness direction indicated with FGV, FGO and FGX. Effective properties of nano-composite structure are estimated through Mixture low. The surrounding elastic foundation is simulated with spring and shear constants. The material properties of shell and elastic medium constants are assumed temperature-dependent. The motion equations are derived using Hamilton's principle applying first order shear deformation theory (FSDT). Based on differential cubature (DC) method, the frequency of nano-composite structure is obtained for different boundary conditions. A detailed parametric study is conducted to elucidate the influences of external applied voltage, elastic medium type, temperature distribution type, boundary conditions, volume percent and distribution type of CNT are shown on the frequency of system. In addition, the mode shapes of shell for the first and second modes are presented for different boundary conditions. Numerical results indicate that applying negative voltage yields to higher frequency. In addition, FGX distribution of CNT is better than other considered cases.

• 한국분무공학회지
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• 제27권1호
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• pp.11-17
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• 2022

In upcoming Post Stage-V and Tier 5 regulations of construction machineries, nitrogen oxide (NOx) emissions are strictly limited in cold start conditions. In response to this, a method of improving NOx conversion efficiency has been applied by installing an electric heating catalyst (EHC) in front of conventional urea-SCR systems so that the evaporation and thermal decomposition of urea-water solution can be promoted in cold start conditions. In this strategy, the evaporation and thermal decomposition of urea-water solution and corresponding NOx conversion efficiency are governed by temperature conditions inside the EHC. Therefore, characterizing the temperature distribution in the EHC under various operating conditions is crucial for the optimized operation and control of the EHC in Urea-SCR systems. In this study, a 1-D modeling analysis was performed to predict the heater surface temperature distribution in EHC under various operating conditions. The reliability of prediction results was verified by comparing them with measurement results obtained using an infrared (IR) camera. Based on 1-D analysis results, the effects of various EHC operation parameters on the heater surface temperature distribution were analyzed and discussed.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1991년도 추계학술대회 논문집 학회본부
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• pp.115-118
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• 1991

The temperature distribution on the superconducting thin-film is analyzed as moving constant field is applied above upper critical field. The distribution of magnetic field is derived in the normal spot. Governing equation is obtained with the help of the equation of conservation of energy. The temperature distribution and the heat dissipation are obtained through computer simulation by the method of numerical analysis. Maximum temperature is occured in the most right side inside normal spot. The temperature is increased abruptly inside the normal spot, and decreased more gradually outside normal spot in the direction of moving field as velocity is increased. Increasing the velocity rather than increasing magnitude of the normal spot and the applied field makes maximum temperature larger. Heat dissipation is affected by the velocity rather than the magnitude of normal spot and the applied field.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1987년도 전기.전자공학 학술대회 논문집(II)
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• pp.1292-1295
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• 1987

In noninvasive temperature measurement within body, this paper is presented temperature measurement method in security and with effect from Applicator by electromagnetic, and it is analyzed heat generation quantity or temperature rise distribution by computer simulation within body. In this paper, two-dimensional model is considered and temperature distribution produced by RF capacitive heating system is analyzed by using Finit Element Method (F.E.M). A passibility of temperature distribution control is examined based on the position and size of Applicator.

• 한국전기전자재료학회:학술대회논문집
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• 한국전기전자재료학회 2001년도 하계학술대회 논문집
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• pp.780-782
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• 2001

The mold transformer has anti-burnt and possibility of small size contrary to oil-immersed transformer. The mold transformer has generally cooling duct between low voltage coil and high voltage coil and also made by one body molding for small size and low loss. In this paper, the temperature distribution of designed 50kVA pole mold transformer for power distribution is investigated by FEM program. The designed transformer is also manufactured and temperature rise test is carried out.

• 한국신재생에너지학회:학술대회논문집
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• 한국신재생에너지학회 2006년도 춘계학술대회
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• pp.431-433
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• 2006

Accurate information on the ground surface temperature is essential for design of a borehole heat exchanger and thus ensuring the performance of a ground source heat pump system along with knowledge on thermal diffusivity and conductivity of ground. In this study we analyzed the shallow subsurface temperature monitoring data of 58 Korea Meteorological Administration synoptic stations. As a result, we compiled mean annual ground surface temperature distribution map using multiple regression analysis of the monitoring data.

• 대한원격탐사학회:학술대회논문집
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• 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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• pp.173-177
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• 2005

The purpose of this study is to analyze the principal causes of increases in air temperature on platforms of railway station. We analyzed the distribution of air temperature on Shinkansen platforms at Station 'A' using Computational Fluid Dynamics (CFD). We focused on the factors that influence the temperature dynamics associated with heat generated by trains and station buildings and their effect on the ambient temperature on platforms. In the case of heat generated by trains, air temperature on Shinkansen platforms increased by 4 to 7 degrees compared to when trains generated no heat. When a 50-m high station building was located on the windward side of the platforms, air temperature on Platform X was 2 degrees higher than when the station buildings were absent. Air? temperature on platforms VII to IX increased progressively, and the maximum air temperature on platform VIII was 3 K higher than if station buildings were absent.