?url_ver=Z39.88-2004&rft_id=10.1109%2FACCESS.2021.3073921&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.au=Zhu%2C+Qiuchen&rft.aulast=Zhu&rft.aufirst=Qiuchen&rft.date=21+April+2021&rft.issn=2169-3536&rft.atitle=Hierarchical+Convolutional+Neural+Network+with+Feature+Preservation+and+Autotuned+Thresholding+for+Crack+Detection&rft.title=IEEE+Access&rft.genre=article