• 제목/요약/키워드: height resolution

검색결과 322건 처리시간 0.027초

근육의 전기자극에 의한 X선 회절 분석연구 (A Study on the X-ray Diffraction of the Muscle by the Electrical Stimulation)

  • 김덕술;송주영
    • 생명과학회지
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    • 제8권4호
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    • pp.373-380
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    • 1998
  • A considerable change observed in X-ray diffraction during the muscle contraction was that the movement of myosin head and conformational change of contractile monecules were occurred in the muscle contraction. Time slice requires tension peak after the onset of stimulation and the height of tension peak depends on the number of twitch cycle. The intensity of I$_{11}$, I$_{10}$, 143${\AA}$ reflection is measured with 5ms time resolution and is recorded in isometric tension. The peak height of I$_{11}$ and 143${\AA}$ intensity is changed after the onset of a stimulation I$_{i}$, and the length of twitch is shortened by successive twitches in the case of stimulation TI$_{i}$. On the other hand, the peak height of I$_{11}$ and 215${\AA}$ intensity starts to decrease at the 1st twitch and remains constant at low peak hight without appreciable recovery during the contraction term. In the case of uccessive twitch stimulation, the myosin heads of muscle are once moved from their resting position and never returned to their initial position.

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대기유동장 수치모의 시 지형해상도의 영향 (Influence of Topography Resolution on Atmospheric Flow Simulation)

  • 우상우;김현구
    • 한국신재생에너지학회:학술대회논문집
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    • 한국신재생에너지학회 2009년도 춘계학술대회 논문집
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    • pp.455-457
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    • 2009
  • The purposes of this study are to consider the influence of topography resolution on atmospheric flow simulation and to suggest a method of atmospheric flow simulation using a low-resolution DEM. Simulations using a low-resolution DEM has more critical error at near surface than simulations using high-resolution DEM because it is ignored the small curve topography of high-resolution DEM. Therefore when we convert the height differences between low-resolution DEM and high-resolution DEM into the topography roughness, we can be able to reduce the error on atmospheric flow simulations.

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INFLUNCE OF THE TOPOGRAPHIC INTERPOLATION METHODS ON HIGH-RESOLUTION WIND FIELD SIMULATION WITH SRTM ELEVATION DATA OVER THE COASTAL AREA

  • Kim, Yoo-Keun;Lo, So-Young;Jeong, Ju-Hee
    • 대한원격탐사학회:학술대회논문집
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    • 대한원격탐사학회 2008년도 International Symposium on Remote Sensing
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    • pp.297-300
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    • 2008
  • High-resolution mesoscale meteorological modeling requires more accurate and higher resolution digital elevation model (DEM) data. Shuttle Radar Topographic Mission (SRTM) has created 90 m DEM for entire globe and that is freely available for meteorological modeling and environmental applications. In this research, the effects of the topographic interpolation methods on high-resolution wind field simulation in the coastal regions were quantitatively analyzed using Weather Research and Forecasting (WRF) model with SRTM data. Sensitivity experiments with three different interpolation schemes (four-point bilinear, sixteen-point overlapping parabolic and nearest neighbor interpolation methods) were preformed using SRTM. In WRF modeling with sixteen-point overlapping parabolic interpolation, the coastal line and some small islands show more clearly than other cases. The maximum height of inland is around 140 meters higher, while the minimum of sea height is about 80 meter lower. As it concerns the results of each scheme it seems that the sixteen-point overlapping parabolic scheme indicates the well agreement with observed surface wind data. Consequently, topographic changes due to interpolation methods can lead to the significant influence on mesoscale wind field simulation of WRF modeling.

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격자유형과 해상도를 고려한 2차원 홍수범람 모델링 (Two-Dimensional(2-D) Flood Inundation Modeling Considering Mesh Type and Resolution)

  • 김병현
    • 대한토목학회논문집
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    • 제39권2호
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    • pp.247-256
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    • 2019
  • 본 연구에서는 홍수모델링을 위해 삼각격자와 사각격자를 포함하는 혼합격자의 적용이 가능한 2차원 Godunov형 유한체적모형을 이용하여 격자형상과 해상도에 따른 홍수위, 홍수범람범위, 모형의 계산시간을 비교 분석하였다. 연구유역은 2000년 10월 29일부터 11월 19일까지 22일 동안 홍수가 발생한 영국의 Upton-upon Severn 유역이다. 홍수 모델링을 위해 고해상도 LiDAR (Light Detection And Ranging)를 이용하여 지형자료를 구축하였으며, 격자유형 및 해상도에 따른 2차원 홍수모델링 결과는 홍수기간 동안 촬영된 4개의 ASAR (Airborne Synthetic Aperture Radar) 영상자료와 비교하였다. 본 연구는 동일한 지형과 경계조건을 사용하더라도, 격자의 형상과 해상도에 따라 홍수위와 범람범위가 큰 차이를 가질 수 있음을 보여주었으며, 2차원 홍수모델링의 목적과 상황에 맞는 적절한 격자유형과 해상도의 선택이 필요함을 보여준다.

고해상도 광학영상과 SAR영상으로부터 생성된 수치표고모델의 정확도 분석 (Accuracy Analysis of DEMs Generated from High Resolution Optical and SAR Images)

  • 김충;이동천;염재홍;이용욱
    • 한국측량학회:학술대회논문집
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    • 한국측량학회 2004년도 춘계학술발표회논문집
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    • pp.337-343
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    • 2004
  • Spatial information could be obtained from spaceborne high resolution optical and synthetic aperture radar(SAR) images. However, some satellite images do not provide physical sensor information instead, rational polynomial coefficients(RPC) are available. The objectives of this study are: (1) 3-dimensional ground coordinates were computed by applying rational function model(RFM) with the RPC for the stereo pair of Ikonos images and their accuracy was evaluated. (2) Interferometric SAR(InSAR) was applied to JERS-1 images to generate DEM and its accuracy was analysis. (3) Quality of the DEM generated automatically also analyzed for different types of terrain in the study site. The overall accuracy was evaluated by comparing with GPS surveying data. The height offset in the RPC was corrected by estimating bias. In consequence, the accuracy was improved. Accuracy of the DEMs generated from InSAR with different selection of GCP was analyzed. In case of the Ikonos images, the results show that the overall RMSE was 0.23327", 0.l1625" and 13.70m in latitude, longitude and height, respectively. The height accuracy was improved after correcting the height offset in the RPC. i.e., RMSE of the height was 1.02m. As for the SAR image, RMSE of the height was 10.50m with optimal selection of GCP. For the different terrain types, the RMSE of the height for urban, forest and flat area was 23.65m, 8.54m, 0.99m, respectively for Ikonos image while the corresponding RMSE was 13.82m, 18.34m, 10.88m, respectively lot SAR image.

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이미지 및 USN 기반 원격 적설량 측정 시스템 (An Image-Based Remote Snow Height Measurement System using a USN)

  • 이형봉;문정호;정태윤
    • 대한임베디드공학회논문지
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    • 제6권2호
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    • pp.76-85
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    • 2011
  • In conventional methods for measuring snow height, a graduated pole is installed on ground in an area of interest and the snow height is manually read from the pole. Recently, automated snow height measurement systems have been introduced to improve the conventional methods. The automated measurement systems, however, are quite expensive since they use the reflection of ultrasonic waves or laser beams. In addition, it is not easy to move the location of the automated measure systems. This paper proposes a snow height measurement system equipped with image sensors and wireless communication capability via a USN and the Internet. The proposed system has a resolution of 5 cm and easy to deploy without difficulties, which can be usefully used to monitor unforseen local snowfalls.

한반도 산악 지역의 지형분산 스펙트럼과 중규모 수치모의에서의 효과 분석 (The Analysis of Terrain Height Variance Spectra over the Korean Mountain Region and Its Impact on Mesoscale Model Simulation)

  • 안광득;이용희;장동언;조천호
    • 대기
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    • 제16권4호
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    • pp.359-370
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    • 2006
  • Terrain height variance spectra for the Korean mountain region are calculated in order to determine an adequate grid size required to resolve terrain forcing on mesoscale model simulation. One-dimensional spectral analysis is applied to specifically the central-eastern part of the Korean mountain region, where topographical-scale forcing has an important effect on mesoscale atmospheric flow. It is found that the terrain height variance spectra in this mountain region has a wavelength dependence with the power law exponents of 1.5 at the wavelength near 30 km, but this dependence is steeply changed to 2.5 at the wavelength less than 30 km. For the adequate horizontal grid size selection on mesoscale simulation two-dimensional terrain height spectral analysis is also performed. There is no directionality within 50% of spectral energy region, so one-dimensional spectral analysis can be reasonably applied to the Korea Peninsula. According to the spectral analysis of terrain height variance, the finer grid size which is higher than 6 km is required to resolve a 90% of terrain variance in this region. Numerical simulation using WRF (Weather Research and Forecasting Model) was performed to evaluate the effect of different terrain resolution in accordance with the result of spectral analysis. The simulated results were quantitatively compared to observations and there was a significant improvement in the wind prediction across the mountain region as the grid space decreased from 18 km to 2 km. The results will provide useful guidance of grid size selection on mesoscale topographical simulation over the Korean mountain region.

복잡한 해안지역의 지역특성을 고려한 대기 유동장에 따른 SO2 (Numerical Simulation of Dispersion Fields of SO2 according to Atmospheric Flow Field to Reflect local characteristics in Complex Coastal Regions)

  • 이화운;원혜영;최현정;이강열;김현구
    • 한국환경과학회지
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    • 제14권3호
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    • pp.297-309
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    • 2005
  • Recently air quality modeling studies for industrial complex and large cities located in the coastal regions have been carried out Especially, the representation of atmospheric flow fields within a model domain is very important, because an adequate air quality simulation requires an accurate portrayal of the realistic three­dimensional wind fields. Therefore this study investigated effect of using high resolution terrain height data and FDDA with observational data to reflect local characteristics in numerical simulation. So the experiments were designed according to FDDA and the detail terrain height with 3sec resolution or not Case 30s was the experiment using the terrain height data of USGS without FDDA and Case 3s was the experiment using the detail terrain height data of Ministry of Environment without FDDA and Case 3sF was experiment using the detail terrain height data of Ministry of Environment with FDDA. The results of experiments were more remarkable, In Case 3s and Case 3sF, temperature indicated similar tendency comparing to observational data predicting maximum temperature during the daytime and wind speed made weakly for difference of terrain height Also Case 3sF had more adequate tendency than Case 3s at dawn.

IFSAR, 방위방향 Aliasing 제거 및 인터페로그램 생성 생성 알고리즘 (IFSAR, Azimuth Aliasing Resolution, and Interferogram Generation Algorithms)

  • 홍인표;박한규
    • 한국통신학회논문지
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    • 제27권4B호
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    • pp.397-402
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    • 2002
  • SAR 데이터를 이용하는 IFSAR 기법은 응용분야가 다양하며, 레이더의 위상정보를 이용하여 고 정밀 고도정보를 추출할 수 있는 유일한 첨단기술이다. 본 논문에서는 IFSAR 기법을 구현하는 전체 알고리즘을 고찰하였다. 그리고 SAR 데이터의 방위방향 aliasing 제거 및 인터페로그램을 생성하는 알고리즘을 제안하였으며, 실험을 통하여 이를 검증하였다. 실험결과 방위방향 aliasing이 제거되고 적합한 인터페로그램이 생성되었다. 따라서 본 논문에서는 정밀한 고도정보를 추출하는데 필수적인 인터페로그램 생성방안 및 IFSAR 알고리즘 주요 모듈에 대한 개발방안을 제시하였다.

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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