Yue Wu Fangfang Qiang Wujie Zhou Weiqing Yan PFCNet: Enhancing Rail Surface Defect Detection With Pixel-Aware Frequency Conversion Networks. 606-610 2025 32 IEEE Signal Process. Lett. https://doi.org/10.1109/LSP.2025.3525855 db/journals/spl/spl32.html#WuQZY25 streams/journals/spl