• Title/Summary/Keyword: Wind Field

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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
    • Proceedings of the KSRS Conference
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    • 2005.10a
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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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Web Service System for GIS-based Storm-surge Visualization (GIS기반 폭풍해일 시각화를 통한 웹 서비스 시스템 구축)

  • Kim, Jin-Ah;Park, K.S.;Kwon, Jae-Il
    • 한국HCI학회:학술대회논문집
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    • 2009.02a
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    • pp.611-614
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    • 2009
  • Understanding the severity of the typhoon-induced storm-surge helps in planning reaction and in preventing further disaster. Natural disasters due to the storm-surge are predictable from accurate observations and forecasts from numerical simulations. What we can do is to make intelligent effort to minimize the loss due to the disaster to the most extent with the technology of early warning, forecast and prevention activity. In this paper, we propose the design of GIS-based Web Service System to visualize the time-varying storm-surge's height and wind field data effectively with 3 different kinds of resolution for predict and prevent storm-surge disasters. This system is one of the efforts to provide the storm-surge forecast service to general public and share two-way more helpful information to coastal resident through the Internet.

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

  • Choi, Jung-Youl;Kim, Jun-Hyung;Lee, Kyu-Yong;Kim, Young-Ki;Park, Jong-Yoon;Song, Bong-Hwan;Seol, Jin-Woong
    • Journal of the Korean Society of Safety
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    • v.32 no.6
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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.

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

  • Kwon, Seo-Yoon;Choi, Eun-Mi;Lim, Chae-Guen;Shin, Dong-Woo;Kim, Kyung-Pil;Kwon, Oh-Kyung;Jeong, Hyun-Mi
    • Fashion & Textile Research Journal
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    • v.14 no.2
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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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    • v.10 no.4
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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.

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

  • Song Museok;Kim Doyoung;Kim Min;Hong Keyyong;Jun Kichun
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.7 no.3
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    • pp.152-157
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    • 2004
  • Wave energy distribution along the Korean coastal sea area was analysed based on the calculated wave data at KORDI. The wave data for the analysis is for the last 24 years (1979∼2002) and the model is HYPA and WAM using known wind field. The wave energy or wave power was evaluated based on the linear wave theory with a simple wave period assumption. The results shed some idea on the amount of usable wave energy and the sites of higher efficiency. It is fair to say that 3kw/m wave energy is easily observable and 10kw/m is frequently available depending on the season and location. The south west region of Jeju island is believed to have the highest overall wave energy density.

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

  • Lee, Gi Yeong;Son, Myeong Hwan
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.31 no.2
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    • pp.17-24
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    • 2003
  • This paper presents results from steady wind tunnel test conducted on a $65^{\circ}$ delta wing at a root chord Reynolds number of $1.76{\times}10^6$. In these experiments, the wing was instrumented with 188 pressure taps, conjunction with powerful multi-channel data logging system, allowed the wing upper surface pressure distribution to be measured. Analysis indicates that the wing upper surface distribution can provide considerable insight into the comvined aerodynamic effects of angle of attack and sideslip on the wing. In a sideslip condition, the strength of the vortex on the windward side is much stronger than that of leeward side. This asymmetric pressure disstribution betwwen each side of wings result in a negative value of rolling moment. However, at a certatin range of angle of attck and sideslip angle(${\alpha}$=$24^{\circ}{\sim}36^{\circ}C$, ${\beta}$=$-5^{\circ}{\sim}-15^{\circ}C$) abrupt change of sign of rolling monent, rolling monent reversal, was observed.

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

  • Han, KangHwi;Lee, Woongsup;Sung, Kil-Young
    • Journal of the Korea Institute of Information and Communication Engineering
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    • v.20 no.12
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    • pp.2348-2354
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    • 2016
  • In recent days, IoT (Internet of Things) technology has been widely used in the field of agriculture, which enables the collection of environmental data and biometric data into the database. The availability of big data on agriculture results in the increase of the machine learning based analysis. Through the analysis, it is possible to forecast agricultural production and the diseases of livestock, thus helping the efficient decision making in the management of smart farm. Herein, we use the environmental and biometric data of Smart Pig farm to derive the accurate relationship model between the environmental information and the daily weight increase of swine and verify the accuracy of the derived model. To this end, we applied the M5P tree algorithm of machine learning which reveals that the wind speed is the major factor which affects the daily weight increase of swine.

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
    • Proceedings of the KSRS Conference
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    • 2004.10a
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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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Evaluation of the Performance of Water Quality Models for the Simulation of Reservoir Flushing Effect on Downstream Water Quality (저수지 플러싱 방류가 하류 수질에 미치는 영향 모의를 위한 수질모델의 성능 평가)

  • Jung, Yong Rak;Chung, Se Woong;Yoon, Sung Wan;Oh, Dong Geun;Jeong, Hee Young
    • Journal of Korean Society on Water Environment
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    • v.25 no.1
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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.