Research on Improved YOLOv7 Based Vehicle Speed and Traffic Flow Detection System - An Ping; Yanfeng Xue; Bohao Yao; Shihao Xiao; Xiang Zhang; Liming Li (Advances in Artificial Intelligence, Big Data and Algorithms - Proceedings of the 3rd International Conference on Artificial Intelligence, Big Data and Algorithms (CAIBDA 2023) - 16-18 June 2023, Zhengzhou, China, 2023)