• Proceedings of the Korean Information Science Society Conference
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• 2000.04b
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• pp.502-504
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• 2000

현재 내용 기반 검색에 대해서 많은 연구가 이루어지고 있다. 본 논문은 이러한 내용기반 검색 방법중에서 영상의 방향 성분을 이용한 텍스쳐 영상 검색 방법을 제안한다. 본 논문에서 제안하는 검색방법은 웨이블릿(Wavelet) 변화후에 생기는 고대역 부밴드들의 Energy 값을 가지고 텍스쳐 영상의 방향 성분을 구한 다음에 방향 성분에 따른 고대역 부밴드의 Energy와 저대역 부밴드의 GLCM(Gray Level Co-occurence Matrix) Energy 값을 가지고 텍스쳐 영상을 검색하도록 하는 방식으로, 실험을 통해서 검색시 좋은 결과를 보여주는 것을 알 수 있었다.

• Journal of Magnetics
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• v.22 no.1
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• pp.34-42
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• 2017

Material defects in the Steam Generator Tubes (SGT) of sodium cooled fast breeder reactor (PFBR) can lead to leakage of water into sodium. The water and sodium reaction will lead to major accidents. Therefore, the examination of steam generator tubes for the early detection of defects is an important requirement for safety and economic considerations. In this work, the Magnetic Flux Leakage (MFL) based Non Destructive Testing (NDT) technique is used to perform the defect detection process. The rectangular notch defects on the outer surface of steam generator tubes are modeled using COMSOL multiphysics 4.3a software. The obtained MFL images are de-noised to improve the integrity of flaw related information. Grey Level Co-occurrence Matrix (GLCM) features are extracted from MFL images and taken as input parameter to train the neural network. A comparative study on characterization have been carried out using feed-forward back propagation (FFBP) and cascade-forward back propagation (CFBP) algorithms. The results of both algorithms are evaluated with Mean Square Error (MSE) as a prediction performance measure. The average percentage error for length, depth and width are also computed. The result shows that the feed-forward back propagation network model performs better in characterizing the defects.