• 태양에너지
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• 제20권1호
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• pp.97-108
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• 2000

The purpose of this study is to minimize the heat transfer surface area and cold fluid exit temperature of heat exchanger which applied to the refrigeration and air-conditioning system by utilizing the thermoelectric principle. Both uniform and non-uniform current distribution methods which applied to the analysis of the TE elements that incorporates heat exchanger were investigated. The non-uniform current distribution method had the better coefficient of performance and had the lower cold fluid exit temperature of the TE cooling system than the uniform current distribution method. It was found that if a TE cooling system incorporates a heat exchanger, a non-uniform current distribution should guarantee to the lowest cold fluid exit temperature. Also, the hybrid method (combination of the uniform and non-uniform current distribution method) is investigated to achieve the best results by combining the uniform and non-uniform current distributions. The results show that it can lower the cold fluid exit temperature and reduce the heat transfer surface area for the parallel flow arrangement if we apply the constant current in some entry region and the non-uniform increasing current in the direction of the cold fluid flow afterwards.

• 대한원격탐사학회지
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• 제35권1호
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• pp.151-162
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• 2019

Surface temperature has been derived from the MODIS/ASTER airborne simulator (MASTER) mid-wave infrared single channel data using the MODerate resolution atmospheric TRANsmission (MODTRAN) radiative transfer model with input data including the University of Wisconsin (UW) emissivity, the National Centers for Environmental Prediction (NCEP) atmospheric profiles, and solar and line-of-sight geometry. We have selected the study area that covers some surface types such as water, sand, agricultural (vegetated) land, and clouds. Results of the current study show the reasonable geographical distribution of surface temperature over land and water similar to the pattern of the MASTER L2 surface temperature. The thorough quantitative validation of surface temperature retrieved from this study is somehow limited due to the lack of in-situ measurements. One point comparison at the Salton Sea buoy shows that the present estimate is 1.8 K higher than the field data. Further comparison with the MASTER L2 surface temperature over the study area reveals statistically good agreement with mean differences of 4.6 K between two estimates. We further analyze the surface temperature differences between two estimates and find primary factors to be emissivity and atmospheric correction.

• 한국해양공학회지
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• 제2권2호
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• pp.104-111
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• 1988

This paper deals with the micro-surface-cracks behavior on the unnotched smooth specimens of Type 304 stainless steel at $593^{\circ}C$ in air under creep and creep-fatigue conditions that have 10 mim and 1 min load holding times respectively. The behaviors of the micro-surface-cracks have been visualized by means of surface replica method and optical micro-photography. The quantitative characteristics of initiation, growth and coalescence of micro-surface-cracks have been investigated by observing and measuring the crack growth behaviors. some of the important results are as follows: Main crack initiates at grain boundary in the early stage(10 to 20%)of its life time and grows through coalescence and finally leads to fracture. The distribution of micro-surface-crack length, 2a, can be plotted against the composite Weibull distribution. The growth rate of the main crack can be plotted against the stress intensity factor, crack tip opering displacement and J integral.

• 한국지리정보학회지
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• 제8권2호
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• pp.21-30
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• 2005

본 연구는 도시지역에서 지표용도를 결정하는 요인으로서 토지이용과 식생분포를 설정하고 이들의 상호관계를 규명하는 것을 목적으로 한다. 이를 위하여 대구광역시를 사례지역으로 위성영상을 판독하고 그 결과를 수치지도와 중첩하여 분석을 실시하였다. 지표온도와 식생지수(표준식생지수)는 위성영상분석을 통하여 도출하였고 토지이용자료는 통계청이 지난 2001년 제작한 기초단위구 자료를 통하여 획득하였다. 분석결과 예상한 바와 같이 지표온도는 식생분포와 토지이용분포와 깊은 상관관계가 있는 가운데 식생상태보다는 토지이용에 의해 더욱 많은 영향을 받는 것으로 나타났다. 이에 따라 본 연구는 토지이용과 지표온도와의 관계규명에 초점을 두었다. 이를 위하여 본 연구는 18개로 구분된 토지이용을 표면온도에 따라 Duncan 검증방법으로 7-8개의 그룹으로 분류하였다. 이에 의하면 지표온도는 제조업과 관련된 토지이용이 많은 지역에서 가장 높았고, 그 뒤를 이어 도심상업지역이 높았다. 반면 농업 및 임야지역의 지표온도가 가장 낮게 나타났다.

• 한국지리정보학회지
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• 제4권1호
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• pp.57-66
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• 2001

본 연구에서는 도시표면온도를 추출하기 위하여 다시기 Landsat TM band 6 영상을 이용하여 과학기술부의 4가지 모델 즉 two-point linear model, linear regression model, quadratic regression model, cubic regression model에 대하여 각각 공간분석을 실시하였으며 그 결과를 AWS(automatic weather station) 관측자료와 상관 및 회귀분석 함과 동시에 GIS 공간분석 기법을 이용하여 도시 표면온도의 공간적 분포특성을 규명하였다. Landsat TM band 6으로부터 추출된 표면온도를 기초로 하여 토지피복별 표면온도 분포를 분석한 결과 도시 및 나지 지역이 가장 높은 온도분포대를 형성하고 있었으며, 표면온도와 NDVI간의 상관분석결과 평균 -0.85 정도의 음의 상관성을 확인할 수 있었다. 이와 같은 결과는 향후 기상환경 특성을 고려한 도시계획수립에 있어 중요한 인자로 작용할 것으로 사료된다.

• Journal of Advanced Marine Engineering and Technology
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• 제26권2호
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• pp.200-208
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• 2002

The flash temperature of the cam-roller contacting surface for a marine diesel engine was analysed numerically. The elastohydrodynamic lubrication pressure and film thickness were adopted to get more accurate frictional coefficient, heat flux and temperature distribution. The maximum flash temperature was increased with both the increasing slip ratio of the contacting surfaces and increasing external load. This study tells that the temperature analysis is an indispensable procedure in designing elastohydrodynamic lubrication contacts on which the slip occurs.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1408-1411
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• 1996

In arc welding processes, because of the complexity and nonlinearity of heat transfer phenomena, it is often difficult to design an effective control system based upon an exact mathematic model. In this paper, we simulated the welding process for various welding conditions and positions to investigate the variations of temperature distribution for those cases. Those will be used as a preinformation for developing quality control system for arc welding process.

• 한국군사과학기술학회지
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• 제17권4호
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• pp.456-462
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• 2014

Infrared(IR) guided heat-seeking missiles uses IR emissions from aircraft to detect and track a target. Due to passive characteristic of the IR guidance, early detection of the missile is difficult and it is significant threat to aircraft survivability. Therefore, IR signature prediction of the aircraft is an important aspect of the stealth technology. In this study, we simulated IR signature of the aircraft in real atmospheric conditions. Aircraft surface temperature distribution was calculated by using RadthermIR code. Based on temperature distribution, IR radiance and BRDF(Bidirectional Reflectance Distribution Function) image were simulated for different weather(seasonal) and background(sky/soil) conditions. The IR contrast tendencies are not aligned with surface temperature or magnitude of target IR radiance. Therefore, it is essential to simulate IR signature with various conditions and background to acquire reliable database.

• 한국주거학회논문집
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• 제25권5호
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• pp.43-50
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• 2014

This study assesses thermal environment of detached housing area by classifying buildings types with codes based on spatial characteristics and forms of the detached housing area and applying heat island alleviation measures, especially focused on FBCs (Form-Based Codes). We analyzed shapes and materials of outdoor space with 3D-CAD, which can affect the surface temperature of the case studies, focusing on heat island alleviation measures, and performed space design by applying relevant climate factors to a simulation. As to the 3D surface temperature and HIP distribution, low-temperature distribution was shown in the case studies when we applied heat island alleviation measures. FBCs (Form- Based Codes) is being developed for the purpose of creating new urban environment. This study is significant because it pays attention to the effects of surface temperatures on accumulation of sensible heat and reviews heat island alleviation measures with outdoor space shapes/materials in order to lower surface temperatures, aiming at improved pleasantness of the detached housing area.

• 한국임상수의학회지
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• 제19권2호
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• pp.121-124
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• 2002

This study was performed to examine the distribution of mean body surface temperature in 11 clinically healthy dogs. In stable state, ventral and dorsal part of each individual is scanned by digital infrared thermography. The body surface temperature of dorsocranial(DCr), dorsocaudal(DCd), ventrocranial(VCr) and ventrocaudal(VCd) regions were measured by Region Of Interersts(ROI). The mean body surface temperatures of adult dogs were higher than those of puppies in each regions. In addition mean body surface temperature of the ventral region was higher than that of dorsal region.