摘要：

目前目标检测技术日趋成熟, 但是针对在线听课行为的识别仍存在挑战。针对在线课堂人为监管力度不足、目标检测模型复杂度较高所导致的在线课堂行为识别不精准、模型计算量较高等问题, 提出一种基于改进的YOLOv8在线听课行为检测与识别方法。首先在YOLOv8n的基础上添加BiFPN双向特征金字塔网络来进行特征融合, 以增加特征提取的能力, 提高模型识别准确度; 其次在Head端采用C3Ghost模块替代C2f模块, 以大幅减少模型计算量。实验结果表明, 提出的YOLOv8n-BiFPN-C3Ghost模型在线上听课行为数据集上的mAP@0.5和mAP@0.5∶0.95指标分别为98.6%和92.6%, 相比其他课堂行为识别模型在精度上最高提升了4.2%和5.7%, 计算量为6.6 GFLOPS, 比原模型降低了19.5%。YOLOv8n-BiFPN-C3Ghost模型能以更低的运算成本精确地实现在线听课行为的检测和识别, 可以实现对学生在线课堂学习情况的动态、科学识别。

关键词: 目标检测, 在线课堂, 听课行为识别, 性能优化, 特征融合

Abstract:

Target detection technology is advancing, but recognizing online listening behavior remains a challenge. Inaccurate identification of online classroom conduct and high model computation owing to limited human supervision and complex target detection models pose problems. To address this, we employed an upgraded YOLOv8-based method to detect and identify online listening behaviors. This approach incorporates a Bidirectional Feature Pyramid Network (BiFPN) to fuse features based on YOLOv8n, thereby enhancing feature extraction and model recognition accuracy. Second, the C3Ghost module is selected over the C2f module on the Head side to minimize the computational burden significantly. The study demonstrates that the YOLOv8n-BiFPN-C3Ghost model achieved an mAP@0.5 score of 98.6% and an mAP@0.5∶0.95 score of 92.6% on an online listening behavior dataset. The proposed model enhanced the accuracy by 4.2% and 5.7%, respectively, compared with other classroom behavior recognition models. Moreover, the required computation amount is only 6.6 GFLOPS, which is 19.5% less than that of the original model. The YOLOv8n-BiFPN-C3Ghost model is capable of detecting and recognizing online listening behavior with greater speed and accuracy while utilizing lower computing costs. This will ultimately enable the dynamic and scientific recognition of online classroom learning among students.

Key words: target detection, online classroom, listening behavior recognition, performance optimization, feature fusion