• Title/Summary/Keyword: Danage Detection

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Damage Detection of Truss Structures Using Nonlinear Parametric Projection Filter (비선형 파라메트릭 사영필터에 의한 트러스 구조물의 손상 검출)

  • Mun, Hyo-Jun;Suh, Ill-Gyo
    • Journal of Korean Association for Spatial Structures
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    • v.4 no.2 s.12
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    • pp.73-80
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    • 2004
  • In this paper, a study of damage detection for 2-Dimensional Truss Structures using the parametric projection filter theorr is presented. Many researchers are interested in inverse problem and one of solution procedures for inverse problems that are very effective is the approach using the filtering algorithm in conjunction with numerical solution methods. In filtering algorithm, the Kalman filtering algorithm is well known and have been applied to many kind of inverse problems. In this paper, the Parametric projection filtering in conjunction with structural analysis is applied to the identification of damages in 2-D truss structures. The natural frequency and modes of damaged truss model are adopted as the measurement data. The effectiveness of proposed method is verified through the numerical examples.

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Detection of Forest Fire and NBR Mis-classified Pixel Using Multi-temporal Sentinel-2A Images (다시기 Sentinel-2A 영상을 활용한 산불피해 변화탐지 및 NBR 오분류 픽셀 탐지)

  • Youn, Hyoungjin;Jeong, Jongchul
    • Korean Journal of Remote Sensing
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    • v.35 no.6_2
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    • pp.1107-1115
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    • 2019
  • Satellite data play a major role in supporting knowledge about forest fire by delivering rapid information to map areas damaged. This study, we used 7 Sentinel-2A images to detect change area in forests of Sokcho on April 4, 2019. The process of classify forest fire severity used 7 levels from Sentinel-2A dNBR(differenced Normalized Burn Ratio). In the process of classifying forest fire damage areas, the study selected three areas with high regrowth of vegetation level and conducted a detailed spatial analysis of the areas concerned. The results of dNBR analysis, regrowth of coniferous forest was greater than broad-leaf forest, but NDVI showed the lowest level of vegetation. This is the error of dNBR classification of dNBR. The results of dNBR time series, an area of forest fire damage decreased to a large extent between April 20th and May 3rd. This is an example of the regrowth by developing rare-plants and recovering broad-leaf plants vegetation. The results showed that change area was detected through the change detection of danage area by forest category and the classification errors of the coniferous forest were reached through the comparison of NDVI and dNBR. Therefore, the need to improve the precision Korean forest fire damage rating table accompanied by field investigations was suggested during the image classification process through dNBR.