Hongbin Liu is a graduate student at the College of Air Traffic Management, Civil Aviation Flight University of China. His research focuses on low-altitude UAV path planning, urban airspace modeling, semantic-risk assessment, and intelligent transportation systems. His recent work investigates GeoSOT-H-based three-dimensional airspace representation, multi-granularity semantic-risk modeling, hierarchical A* path planning, and dynamic replanning under temporary no-fly constraints for urban low-altitude UAV emergency supply delivery. He is also interested in airport surface operation safety and computer vision-based risk perception.