• 제목/요약/키워드: Wind Field

검색결과 1,589건 처리시간 0.042초

A STUDY ON EXTRACTING THE SURFACE TEMPERATURE USING THERMAL INFRARED OF ASTER IMAGES IN URBAN AREA

  • Jo Myung-Hee;Kim Hyung-Sub;Kim Sung-Jae;Yu Seong-Ok
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2005년도 Proceedings of ISRS 2005
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    • pp.717-720
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    • 2005
  • Recently as large sized urban development and the city ward drifting of population are caused, the urban surface temperature is raised very seriously and rapidly. These artificial developments have destroyed the inner and outer landscapes such as topography and have changed complex local climate such as a sudden rise in temperature, the change of wind field and air pollution. In order to clarify this problem visually, the studies on extracting the thermal infrared and the characteristic analysis of local climate in urban area had been performed by using the sixth band of Landsat TM and ETM+. However, there is a need to alternate Landsat TM and ETM+ because these satellite images are not applied any more. Therefore, in this paper it is proposed to use 2 Aster image (2004.4.17 daily 2b03, 2004.10.10 night 2b03) of EOS AM and to extract the surface temperature. Also, the pattern of surface temperature in urban area and the application possibility in local climate study are proposed by verifying the correlation with A WS data. Also, IKONOS image was used to figure out the artificial development area in visual.

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GIS기반 폭풍해일 시각화를 통한 웹 서비스 시스템 구축 (Web Service System for GIS-based Storm-surge Visualization)

  • 김진아;박광순;권재일
    • 한국HCI학회:학술대회논문집
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    • 한국HCI학회 2009년도 학술대회
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    • pp.611-614
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    • 2009
  • 최근 지구온난화로 인한 기후변화 및 해수면 상승으로 인한 태풍의 내습빈도 및 강도의 증가로 태풍 내습시 연안지역에서 침수 범람과 같은 자연재해로 인한 국민의 인명과 재산 피해가 급증하고 있다. 이에 폭풍 해일 예측을 위한 수치모델의 수립과 개선을 통하여 태풍으로 인해 발생하는 연안지역에서의 해일의 발생시간, 해일의 높이, 해일로 인한 침수 범람 지역을 보다 과학적으로 정확하게 예측하는 연구가 활발히 진행되고 있다. 따라서 본 논문에서는 이러한 예측결과를 일반 국민들에게 보다 효과적으로 전달하고, 폭풍 해일로 인한 침수 범람과 같은 연안재해로 인한 피해를 예방하기 위하여 웹 서비스를 통한 GIS기반 폭풍 해일 시각화 시스템을 개발하였다. 또한 수치모델의 정확한 예측결과 및 연안지역의 정밀 지리정보 구축을 위하여 LiDAR 자료를 이용한 GIS기반 육도-해도 접합을 통한 연안지역의 수 센티미터 해상도의 상세 지리정보를 DEM을 통하여 시각화하였다.

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희생양극법을 이용한 레일부식 저감 방안에 관한 연구 (A Study on Mitigation of Rail Corrosion using Sacrificial Anode Cathodic Protection Method)

  • 최정열;김준형;이규용;김영기;박종윤;송봉환;설진웅
    • 한국안전학회지
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    • 제32권6호
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    • pp.54-60
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    • 2017
  • A railway rail will be corroded by the repetitive sea wind and fog in the splash and tidal zone such as Youngjong grand bridge. And these rusts of rail could be increased by increasing service period, and it frequently occurred the safety accidents or disorders in electrical problem. In this study, the sacrificial anode cathodic protection method was proposed as a measures for reducing the corrosion of the railway rails in the oceanic climate conditions. As the results of immersion test using the salt water during four months, the sacrificial anode cathodic protection method using the aluminum anode(Al-anode) was evaluated that a distinct effect on corrosion reduction in the rails. Therefore the sacrificial anode cathodic protection method was experimentally proven that a disorders in aspects electric and signal of railway operation condition such as direct fixation track system in Youngjong grand bridge could be prevented by reducing rust falling from the rail. In addition, the installation conditions of the anodes directly affect the transmission range of corrosion potential, the sectional loss of anode, and the corrosion reduction effect. Therefore, to expect the corrosion reduction effect of rails under the oceanic climate conditions for railway track, it was important to adopted the appropriate spacing of anode installation by considering the actual field conditions.

전차병 점퍼의 착용만족도 및 보온성에 관한 연구 (A Study on Wearing Satisfaction and Thermal Properties of Jumper for Korean Military Tank Drivers)

  • 권서윤;최은미;임채근;신동우;김경필;권오경;정현미
    • 한국의류산업학회지
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    • 제14권2호
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    • pp.261-268
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    • 2012
  • The purpose of this study is to investigate problems of design, fitness, suitability for movement, and wearing comfort of jumper for Korean military tank drivers through analysis of actual wearing condition by questionnaire and field evaluation and to provide basic data for developing its improved design. The survey was done for 477 military tank drivers and evaluation was performed using thermal manikin to measure insulation. The overall satisfaction for design of jumper for military tank driver was over 3.5(likert scale). The overall satisfaction for fitness of jumper for military tank driver was also over 3.5. The satisfactions for material was between 2.39 and 3.13 and the satisfaction for pilling property was the lowest, followed by static property and shape stability after laundering. The satisfactions for movement suitability were standing(3.81), sitting(3,38), raising hand(forward: 2.90, sideward: 3.01), respectively. In insulation evaluation of jumper for military tank drivers and outwears(jacket, jumper), the insulation of jumper for military tank drivers was lower than outwear(jumper) and same with outwear(jacket). The insulation in dynamic and still condition(without wind) of jumper for military tank driver was 0.37clo and 0.31clo, respectively. Its decreation rate in dynamic condition comparing to still condition was 59% which was lower than jacket(0.73clo) and jumper(1.15clo).

An Experimental and Numerical Study of Corona in a Cage with Sandy and Dusty Flow in High Altitude Area

  • Lv, Yukun;Ge, Zekun;Liu, Yunpeng;Zhu, Lei;Wei, Shaoke
    • Journal of Electrical Engineering and Technology
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    • 제10권4호
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    • pp.1726-1733
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    • 2015
  • In order to study the effect of the high-altitude and dusty weather in northwest of China on the corona characteristics of transmission lines, a corona caged based experimental system with sandy and dusty flow condition is numerically investigated and designed. This system overcomes the difficulties caused by harsh environment and offers easy usage for off-site tests. The design parameters are mainly determined by the characteristics of strong sandstorm in northwest region and test requirements. By the comparison of numerical simulation of the particle diffusion in four programs with rectangular or circular air-duct, a practical technology, which introduces swirl to control the particle diffusion length, is obtained. Accordingly, the structure of round air-duct with swirl elbow in inlet and outlet of high level segment is selected as final program. Systems of control and measurement are designed at the same time. Field tuning results show that the test system could ensure the range of sandy and dusty coverage. The wind speed, sandy and dusty concentration could be controlled and meet the requirements of accuracy. The experimental system has many features, such as simple structure, easy to be assembled, disassembled, transported and operated, small space occupied.

장기 수치모사 파랑자료를 바탕으로 한 한국해역의 파랑에너지밀도 분석 (Analysis of Wave Energy Density for Korean Coastal Sea Area Based on Long-Term Simulated Wave Data)

  • 송무석;김도영;김민;홍기용;전기천
    • 한국해양환경ㆍ에너지학회지
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    • 제7권3호
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    • pp.152-157
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    • 2004
  • 한국해양연구원(KORDI)의 파랑자료를 기초로 하여 한반도 근해의 파랑에너지 분포를 분석하였다. 파랑자료는 최근 24년(1979∼2002)간의 바람자료를 바탕으로 HYPA와 WAM모델을 이용하여 모사된 것이다. 파랑에너지, 즉 파력의 평가는 선형이론에 근거한 파주기를 가정하는 형태를 이용하여 하였다. 대략 3 kw/m 정도의 가용 파랑에너지가 한반도 근해에 분포한다고 말할 수 있으며, 계절과 지역에 따라 10 kw/m이상의 파랑에너지가 나타나는 곳도 있다. 제주도의 남서쪽 해역이 상대적으로 양질의 파랑에너지가 존재하는 것으로 평가된다.

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삼각날개 와류장에서의 옆미끄럼과 받음각의 복합효과 (Combined Effects of Sideslip and AOA on the Vortical Flow of Delta Wing)

  • 이기영;손명환
    • 한국항공우주학회지
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    • 제31권2호
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    • pp.17-24
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    • 2003
  • 본 논문은 $65^{\circ}$ 후퇴각을 갖는 삼각날개에 대하여 뿌리시위를 기준으로 한 레이놀즈수 $1.76{\times}10^6$에서 정상 풍동실험에 의한 결과를 보였다. 풍동실험은 총 188개의 압력공과 다채널 데이터 처리 시스템을 사용하여 날개 윗면에서의 압력 분포를 측정하였다. 날개 윗면에서의 압력분포의 분석으로부터 옆미끄럼각과 받음각이 날개의 공력 특성에 미치는 복합적인 영향에 대한 직관을 얻을 수 있었다. 옆미끄럼각이 있는 경우, 바람쪽 날개의 와류강도는 바람 반대쪽 날개의 화류강도보다 훨씬 강하였다. 이와 같은 좌우 날개의 비대칭적인 압력분포로 인하여 음의 롤링모멘트가 발생하였다. 하지만, 일정 범위의 받음각과 옆미끄럼각(${\alpha}$=$24^{\circ}{\sim}36^{\circ}C$, ${\beta}$=$-5^{\circ}{\sim}-15^{\circ}C$)에서는 롤링모멘트의 방향이 갑자기 바뀌는 롤링모멘트 역전현상을 관찰할 수 있었다.

의사결정트리를 이용한 돈사 환경데이터와 일당증체 간의 연관성 분석 모델 개발 (Development of a model to analyze the relationship between smart pig-farm environmental data and daily weight increase based on decision tree)

  • 한강휘;이웅섭;성길영
    • 한국정보통신학회논문지
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    • 제20권12호
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    • pp.2348-2354
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    • 2016
  • 최근 농업분야에서 IoT(Internet of Things)기술을 통해 다양한 생체 및 환경 정보를 DB(data base)로 구축할 수 있게 되면서 빅 데이터를 이용한 기계학습 분석이 증가하고 있다. 기계학습 분석을 통해 농업의 생산량과 가축의 질병 등을 예측할 수 있게 되어 농업경영에서 효율적인 의사결정을 돕는다. 본 논문에서는 스마트 돈사의 다양한 환경데이터와 몸무게데이터를 이용하여 환경정보와 일당증체의 연관성 모델을 도출하고 그 정확도를 분석하였다. 이를 위해 기계학습의 M5P tree기법을 적용하였다. 분석을 통해 일당증체량이 풍속에 큰 영향을 받는 것을 확인하였다.

Development of a Government GIS for Forest Management at Hsinchu County in Taiwan

  • WU Mu-Lin;CHEN Shiann-Kai;FU Chi-Mei;FAN Jeng-Peng;FU Shyh-Shiou
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2004년도 Proceedings of ISRS 2004
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    • pp.68-71
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    • 2004
  • Hsinchu Science Park, one of the most productive electronic sites in the world, is located at Hsinchu County. Hsinchu County Government is entitled for daily management to pursue the objectives of making every county citizen prosperous. Several web-based management information systems have been developed for county management and were widely implemented. However, forest management is one of several tasks which need development of web-based geographic information systems. The objectives of this paper are to develop GIS for forest management at Hsinchu County in order to solve problems encountered in the rapid changing circumstance. The objectives of forest management at Hsinchu County have been changed a little bit in the last decade. Now, it mainly focuses on public and private forest, tree planting, wind break forest management, and plane forest planting. The major ingredients of GIS for forest management are user-friendly, task-oriented, and direct linking to the existing GIS at Hsinchu County. AreIMS and ArcGIS were used for web-based GIS. Field operations of forest management depend on PDA and GPS such that ArcPAD is implemented both on personal computers and PDA. Computer programming is required for database management and development of application modules in forest management. Color digital orthophoto maps at scale of 1:5000 provide very useful background information. Forest management at Hsinchu County now is operated in an efficient way that GIS, remote sensing, GPS and PDA are working smoothly.

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저수지 플러싱 방류가 하류 수질에 미치는 영향 모의를 위한 수질모델의 성능 평가 (Evaluation of the Performance of Water Quality Models for the Simulation of Reservoir Flushing Effect on Downstream Water Quality)

  • 정용락;정세웅;윤성완;오동근;정희영
    • 한국물환경학회지
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    • 제25권1호
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    • pp.48-57
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    • 2009
  • A two-dimensional (2D), laterally-averaged hydrodynamic and water quality model, CE-QUAL-W2 was applied to evaluate the performance on simulating the effect of flushing from Daecheong Reservoir on the downstream water quality variations during the flushing events held on November, 2003 and March, 2008. The hydraulic and water quality simulation results were compared with field measurement data, as well as a one-dimensional (1D), unsteady model (KORIV1) that revealed limited capability in the previous study due to missing the resuspension process of river bottom sediments. The results showed that although the 2D model made satisfactory performance in reproducing the temporal variations of dissolved matters including phosphate, ammonia and nitrate, it revealed poor performance in simulating the increase of biological oxygen demand and suspended sediment (SS) concentrations during the passage of the flushing flow. The reason of the error was that the resuspension process of the 2D model is only the function of shear stress induced by wind. In reality, however, as shown by significant correlation between bottom shear stress ($\tau$) and observed SS concentration, the resuspension process can be significantly influenced by current velocity in the riverine system, especially during flushing event. The results indicate that the resuspension of river bottom materials should be incorporated into the water quality modeling processes if $\tau$ is greater than a critical shear stress (${\tau}_c$) for better simulation of flushing effect.