Zhentao Liu Xue Ye Fang Sun Yi Lu PHTop: Sketch Recognition Technology Based on Graph Topology Neural Network. 1-8 2025 IJCNN https://doi.org/10.1109/IJCNN64981.2025.11229388 conf/ijcnn/2025 db/conf/ijcnn/ijcnn2025.html#LiuYSL25 streams/conf/ijcnn