目的:为解决人脸口罩识别中边缘和移动端设备存储与计算资源受限的问题,提出一种基于YOLOv5轻量化网络的人脸口罩识别方法。方法:选取由主干网络(Backbone)、颈部模块(Neck)和头部模块(Head)组成的YOLOv5模型作为基础框架。首先,使用Shu...目的:为解决人脸口罩识别中边缘和移动端设备存储与计算资源受限的问题,提出一种基于YOLOv5轻量化网络的人脸口罩识别方法。方法:选取由主干网络(Backbone)、颈部模块(Neck)和头部模块(Head)组成的YOLOv5模型作为基础框架。首先,使用ShuffleNetv2轻量化网络对Backbone部分进行修改替换;其次,在Neck部分引入Ghost模块和C3_S模块;最后,为提升检测精度,融入卷积块注意力模块(convolutional block attention module,CBAM),形成Shuffle_Yolo_GS_CBAM模型。选用AIZOO数据集训练和验证模型,通过平均精度均值(mean average precision,mAP)、每秒传输帧数(frames per second,FPS)、每秒10亿次的浮点运算数(giga floating-point operations per second,GFLOPS)和参数量评估模型对人脸口罩的识别效果。结果:该模型识别人脸口罩的mAP为89.5%,FPS为158.7帧/s,参数量和GFLOPS分别为2.38 M和4.5 GFLOPS。与YOLOv5s相比,虽然检测精度略有下降,但检测速度提升了39.7%,模型参数量减少了67.3%,模型运算量减少了73.8%。结论:提出的方法在提高检测速度、减少参数量和计算量、保障检测精度方面表现良好,适合部署在边缘和移动端设备上进行人脸口罩识别。展开更多
Despite cities being recognized as being potential sources of microplastic pollution to the wider environment, most surveys of COVID-19 plastic-based litter have been undertaken through linear transects of marine beac...Despite cities being recognized as being potential sources of microplastic pollution to the wider environment, most surveys of COVID-19 plastic-based litter have been undertaken through linear transects of marine beaches. For the far fewer number of studies conducted on inland and urban locations, the site-specific focus has primarily been surveys along the length of streets. The present study is the first to specifically assess the standing stock (i.e., moment-in-time) of littered face masks for the entire surface area of urban parking lots. The density of face masks in 50 parking lots in a Canadian coastal town (0.00054 m2 ± 0.00051 m2) was found to be significantly greater than the background level of littering of town streets. Face mask density was significantly related to visitation “usage” of parking lots as gauged by the areal size of the lots and of their onsite buildings, as well as the number of vehicles present. Neither parking lot typology nor estimates of inferred export (various measures of wind exposure) and entrapment (various metrics of obstruction) of face masks had a significant influence on the extent of whole-lot littering. In consequence, modelling of the potential input of mask-derived microplastics to the marine environment from coastal communities can use the areal density of face masks found here in association with the total surface area of lots for individual municipalities as determined through GIS analysis.展开更多
文摘目的:为解决人脸口罩识别中边缘和移动端设备存储与计算资源受限的问题,提出一种基于YOLOv5轻量化网络的人脸口罩识别方法。方法:选取由主干网络(Backbone)、颈部模块(Neck)和头部模块(Head)组成的YOLOv5模型作为基础框架。首先,使用ShuffleNetv2轻量化网络对Backbone部分进行修改替换;其次,在Neck部分引入Ghost模块和C3_S模块;最后,为提升检测精度,融入卷积块注意力模块(convolutional block attention module,CBAM),形成Shuffle_Yolo_GS_CBAM模型。选用AIZOO数据集训练和验证模型,通过平均精度均值(mean average precision,mAP)、每秒传输帧数(frames per second,FPS)、每秒10亿次的浮点运算数(giga floating-point operations per second,GFLOPS)和参数量评估模型对人脸口罩的识别效果。结果:该模型识别人脸口罩的mAP为89.5%,FPS为158.7帧/s,参数量和GFLOPS分别为2.38 M和4.5 GFLOPS。与YOLOv5s相比,虽然检测精度略有下降,但检测速度提升了39.7%,模型参数量减少了67.3%,模型运算量减少了73.8%。结论:提出的方法在提高检测速度、减少参数量和计算量、保障检测精度方面表现良好,适合部署在边缘和移动端设备上进行人脸口罩识别。
文摘Despite cities being recognized as being potential sources of microplastic pollution to the wider environment, most surveys of COVID-19 plastic-based litter have been undertaken through linear transects of marine beaches. For the far fewer number of studies conducted on inland and urban locations, the site-specific focus has primarily been surveys along the length of streets. The present study is the first to specifically assess the standing stock (i.e., moment-in-time) of littered face masks for the entire surface area of urban parking lots. The density of face masks in 50 parking lots in a Canadian coastal town (0.00054 m2 ± 0.00051 m2) was found to be significantly greater than the background level of littering of town streets. Face mask density was significantly related to visitation “usage” of parking lots as gauged by the areal size of the lots and of their onsite buildings, as well as the number of vehicles present. Neither parking lot typology nor estimates of inferred export (various measures of wind exposure) and entrapment (various metrics of obstruction) of face masks had a significant influence on the extent of whole-lot littering. In consequence, modelling of the potential input of mask-derived microplastics to the marine environment from coastal communities can use the areal density of face masks found here in association with the total surface area of lots for individual municipalities as determined through GIS analysis.
