• 제목/요약/키워드: spatial/temporal resolution

검색결과 425건 처리시간 0.029초

히마와리 위성의 산불방사열에너지 자료를 이용한 산불배출가스 추정: 2017년 삼척 및 강릉 산불을 사례로 (Estimation of Fire Emissions Using Fire Radiative Power (FRP) Retrieved from Himawari-8 Satellite)

  • 김대선;원명수;이양원
    • 대한원격탐사학회지
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    • 제33권6_1호
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    • pp.1029-1040
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    • 2017
  • 산불은 다량의 온실가스를 대기 중으로 방출하는 자연재해로서, 이를 효율적으로 감시하기 위해서는 정지궤도 위성의 산불방사열에너지(fire radiative power, FRP)를 활용하는 방법이 필요하다. 본 연구에서는 2017년 5월 6일에 발생한 우리나라 삼척과 강릉 산불을 사례로, 히마와리 위성의 중적외 채널자료를 이용하여 FRP를 산출하였으며, 이를 통해 MODIS(Moderate Resolution Imaging Spectroradiometer)의 제한적인 시간해상도로는 관측이 불가능한 10분 간격의 산불 피해강도의 실시간 모니터링이 가능함을 확인하였다. 또한 히마와리 FRP를 이용하여 강릉 산불의 배출가스를 계산하였으며, 에어코리아 실측치와 비교하였을 때 거리 차에 의한 1~3시간의 지연현상과 함께, 산불배출가스의 시계열 패턴이 매우 잘 일치함을 알 수 있었다. 또한 선행연구에서 고해상도 영상분석을 통해 제시한 산불배출가스 추정량과 비교하였을 때, 100 ha당 배출량이 삼척은 약 12%, 강릉은 약 2%의 차이로 매우 유사한 결과를 나타냈다. 이는 산불 피해면적과 피해강도에 대한 직접적인 분석 없이도, 정지궤도 위성의 FRP만을 이용하여 산불배출가스의 정밀한 추정이 가능함을 의미한다. 이 연구는 향후 발사될 우리나라 정지궤도 기상위성인 GK-2A(Geostationary Korea Multi-Purpose Satellite-2A)의 산불배출가스 추정 및 에어로솔 산출에 활용될 수 있을 것으로 사료된다.

X선관을 이용한 불투명한 물체 내부 유동의 정량적 가시화 연구 (Quantitative Flow Field Visualization of a Flow inside an Opaque Tube Using Angiographic PIV Method)

  • 김국배;임남윤;류재춘;임대현;이형구;이상준
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2007년도 춘계학술대회B
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    • pp.2935-2940
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    • 2007
  • To diagnose circulatory diseases in the viewpoint of hemodynamics, we need to get quantitative hemodynamic information of blood flows related with the vascular diseases with high spatial resolution of tens micrometer and high temporal resolution in the order of millisecond. For investigating in-vivo hemodynamic phenomena, a new diagnosing technique combining medical radiography and PIV method was newly proposed and developed. This angiographic PIV technique consists of a medical X-ray tube, an X-ray CCD camera, a shutter module for double pulses of X-ray, and a synchronizer. The feasibility of the angiographic PIV technique was tested and quantitative flow velocity field distribution of a flow inside an opaque conduit was acquired by the developed system. It can be used for measuring flow phenomena of nontransparent fluids inside opaque conduits.

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국가바람지도 활용시스템 KIER-WindMap$^{TM}$ (Application System for National Wind Map KIER-WindMap$^{TM}$)

  • 김현구;강용혁;이화운;정우식
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.532-533
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    • 2009
  • The national wind map of South Korea has been established as a core data to support national strategy building and promotion of wind energy dissemination. The national wind map has been made by numerical wind simulation with the spatial resolution of 1 km horizontal, 10m vertical and temporal resolution of 1 hour interval for 5 years period (2003-2007). Therefore, an application system linked with the national wind map named KIER-WindMap$^{TM}$ is being developed to be used by the government, local government, developers and researchers. We introduce the current status of the application system and the future development plans.

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국가바람지도 구축전략 수립을 위한 해외사례 분석 (Global Case Study to Setup Establishment Strategy of National Wind Map)

  • 황효정;김현구
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.458-459
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    • 2009
  • This global case study pursues diversification and intensification for an application system of the national wind map which has been developed to support national strategy building and promotion of wind energy dissemination. We chose nine counties' national wind maps and compared their map area, extraction height, temporal and spatial resolution, download services, etc. to derive a best practice for the Korea wind map application system. Therefore, the application system are designed to offer high resolution height information of which covers wind turbine rotor sweeping area and time-series dataset which can be downloaded for further analysis by users. It is anticipated that the system would contribute greatly to wind energy policy, business and research sectors once the derived ideas have been implemented to the application system

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Global GPS Ionospheric Modelling Using Spherical Harmonic Expansion Approach

  • Choi, Byung-Kyu;Lee, Woo-Kyung;Cho, Sung-Ki;Park, Jong-Uk;Park, Pil-Ho
    • Journal of Astronomy and Space Sciences
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    • 제27권4호
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    • pp.359-366
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    • 2010
  • In this study, we developed a global ionosphere model based on measurements from a worldwide network of global positioning system (GPS). The total number of the international GPS reference stations for development of ionospheric model is about 100 and the spherical harmonic expansion approach as a mathematical method was used. In order to produce the ionospheric total electron content (TEC) based on grid form, we defined spatial resolution of 2.0 degree and 5.0 degree in latitude and longitude, respectively. Two-dimensional TEC maps were constructed within the interval of one hour, and have a high temporal resolution compared to global ionosphere maps which are produced by several analysis centers. As a result, we could detect the sudden increase of TEC by processing GPS observables on 29 October, 2003 when the massive solar flare took place.

Analysis of Solar Surface Data Obtained by Domless Solar Telescope of Hida observatory

  • 김현남;;;김갑성;최광선
    • 천문학회보
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    • 제35권1호
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    • pp.28.1-28.1
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    • 2010
  • Ground-based solar observations have several merits such as wider field of view and higher time cadence than those of satellite observations. The Domeless Solar Telescope of Hida Observatory is designed to acquire solar surface images at the highest possible spatial resolution using two types of spectrographs: a vertical spectrograph with the highest wavelength resolution in the world, and a horizontal spectrograph that can take images of the sun in multi-wavelength over the entire visible solar spectrum. The temporal variation of fine features such as chromospheric grains in the supergranulation cells and facular points in the network region has been obtained using DST Ca II K lines compared with Hinode Ca II H lines. This analysis is expected to provide a fundamental tool for research of diverse phenomena on the solar surface.

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Angiographic PIV기법 개발 및 성능 평가 (Development of angiographic PIV and performance evaluation)

  • 정성용;김국배;임남윤;이상준
    • 한국전산유체공학회:학술대회논문집
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    • 한국전산유체공학회 2008년도 춘계학술대회논문집
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    • pp.683-686
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    • 2008
  • To diagnose vascular diseases from the viewpoint of hemodynamics, detailed quantitative hemodynamic information of related blood flows with a high spatial resolution of tens micrometer and a high temporal resolution in the order of millisecond were required. For investigating the hemodynamic phenomena of vascular circulatory diseases, a new diagnosing technique combining a medical radiography and PIV method was newly developed. This technique consisted of a medical X-ray tube, an X-ray CCD camera, a shutter module for double pulse-type X-ray source, and a synchronizer. Through several preliminary tests, the feasibility of the angiographic PIV technique was verified. For in-vivo measurements to real blood flows, we developed tracer microcapsules which were optimized to this system by encapsulating a contrast material of iodine with a matrix material of PVA (polyvinylpyrrolidone). In near future, the angiographic PIV technique would be useful for diagnosing hemodynamic phenomena of vascular diseases and for their early detection.

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Assessing the Nano-Dynamics of the Cell Surface

  • Bae, Chil-Man;Park, Ik-Keun;Butler, Peter J.
    • 비파괴검사학회지
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    • 제32권3호
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    • pp.263-268
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    • 2012
  • It is important to know the mechanism of cell membrane fluctuation because it can be readout for the nanomechanical interaction between cytoskeleton and plasma membrane. Traditional techniques, however, have drawbacks such as probe contact with the cell surface, complicate analysis, and limit spatial and temporal resolution. In this study, we developed a new system for non-contact measurement of nano-scale localized-cell surface dynamics using modified-scanning ion-conductance microscopy. With 2 nm resolution, we determined that endothelial cells have local membrane fluctuations of ~20 nm, actin depolymerization causes increase in fluctuation amplitude, and ATP depletion abolishes all membrane fluctuations.

Application of the 3D Discrete Wavelet Transformation Scheme to Remotely Sensed Image Classification

  • Yoo, Hee-Young;Lee, Ki-Won;Kwon, Byung-Doo
    • 대한원격탐사학회지
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    • 제23권5호
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    • pp.355-363
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    • 2007
  • The 3D DWT(The Three Dimensional Discrete Wavelet Transform) scheme is potentially regarded as useful one on analyzing both spatial and spectral information. Nevertheless, few researchers have attempted to process or classified remotely sensed images using the 3D DWT. This study aims to apply the 3D DWT to the land cover classification of optical and SAR(Synthetic Aperture Radar) images. Then, their results are evaluated quantitatively and compared with the results of traditional classification technique. As the experimental results, the 3D DWT shows superior classification results to conventional techniques, especially dealing with the high-resolution imagery and SAR imagery. It is thought that the 3D DWT scheme can be extended to multi-temporal or multi-sensor image classification.

High-speed Two-photon Laser Scanning Microscopy Imaging of in vivo Blood Cells in Rapid Circulation at Velocities of Up to 1.2 Millimeters per Second

  • Boutilier, Richard M.;Park, Jae Sung;Lee, Ho
    • Current Optics and Photonics
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    • 제2권6호
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    • pp.595-605
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    • 2018
  • The two-photon process of microscopy provides good spatial resolution and optical sectioning ability when observing quasi-static endogenous fluorescent tissue within an in vivo animal model skin. In order to extend the use of such systems, we developed a two-photon laser scanning microscopy system capable of also capturing $512{\times}512$ pixel images at 90 frames per second. This was made possible by incorporating a 72 facet polygon mirror which was mounted on a 55 kRPM motor to enhance the fast-scan axis speed in the horizontal direction. Using the enhanced temporal resolution of our high-speed two-photon laser scanning microscope, we show that rapid processes, such as fluorescently labeled erythrocytes moving in mouse blood flow at up to 1.2 mm/s, can be achieved.