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改进YOLOv7的PCB缺陷检测算法 被引量:5
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作者 王玲 向北平 张晓勇 《机械科学与技术》 北大核心 2025年第1期9-18,共10页
针对检测印刷电路板(Printed circuit board, PCB)缺陷任务中,通用物体检测算法难以区分目标缺陷与背景,从而导致检测精度低等问题,提出一种改进YOLOv7的PCB表面缺陷检测模型。首先,在主干提取网络用Conv2Former(Transformer-style conv... 针对检测印刷电路板(Printed circuit board, PCB)缺陷任务中,通用物体检测算法难以区分目标缺陷与背景,从而导致检测精度低等问题,提出一种改进YOLOv7的PCB表面缺陷检测模型。首先,在主干提取网络用Conv2Former(Transformer-style convolutional network)模块替代ELAN模块,保留空间信息的同时加强全局信息关联性,有效减少参数量。其次,删除20×20的大目标检测层,增加160×160的小目标检测层,以此保留更多小目标信息。此外,在特征融合网络引入SimAM(Similarity-based attention mechanism)注意力机制,不引入额外参数的同时提升检测精确度。最后,将Focal损失函数与CIoU损失函数结合,优化损失函数中高质量与低质量样本的权重分配,提升检测效果。实验结果表明,改进后的模型平均检测精度达到95.3%,相较于原模型精度提高了3.6%,参数量为10.97 MB,仅为原模型参数量的三分之一,改进后的模型能够更准确地识别PCB缺陷,有效降低漏检和误检率。 展开更多
关键词 PCB表面缺陷检测 YOLOv7 conv2former SimAM Focal-CIoU
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CNN-BiLSTM-Attention Model in Forecasting Wave Height over South-East China Seas 被引量:6
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作者 Lina Wang Xilin Deng +4 位作者 Peng Ge Changming Dong Brandon J.Bethel Leqing Yang Jinyue Xia 《Computers, Materials & Continua》 SCIE EI 2022年第10期2151-2168,共18页
Though numerical wave models have been applied widely to significant wave height prediction,they consume massive computing memory and their accuracy needs to be further improved.In this paper,a two-dimensional(2D)sign... Though numerical wave models have been applied widely to significant wave height prediction,they consume massive computing memory and their accuracy needs to be further improved.In this paper,a two-dimensional(2D)significant wave height(SWH)prediction model is established for the South and East China Seas.The proposed model is trained by Wave Watch III(WW3)reanalysis data based on a convolutional neural network,the bidirectional long short-term memory and the attention mechanism(CNNBiLSTM-Attention).It adopts the convolutional neural network to extract spatial features of original wave height to reduce the redundant information input into the BiLSTM network.Meanwhile,the BiLSTM model is applied to fully extract the features of the associated information of time series data.Besides,the attention mechanism is used to assign probability weight to the output information of the BiLSTM layer units,and finally,a training model is constructed.Up to 24-h prediction experiments are conducted under normal and extreme conditions,respectively.Under the normal wave condition,for 3-,6-,12-and 24-h forecasting,the mean values of the correlation coefficients on the test set are 0.996,0.991,0.980,and 0.945,respectively.The corresponding mean values of the root mean square errors are measured at 0.063 m,0.105 m,0.172 m,and 0.281 m,respectively.Under the typhoon-forced extreme condition,the model based on CNN-BiLSTM-Attention is trained by typhooninduced SWH extracted from the WW3 reanalysis data.For 3-,6-,12-and 24-h forecasting,the mean values of correlation coefficients on the test set are respectively 0.993,0.983,0.958,and 0.921,and the averaged root mean square errors are 0.159 m,0.257 m,0.437 m,and 0.555 m,respectively.The model performs better than that trained by all the WW3 reanalysis data.The result suggests that the proposed algorithm can be applied to the 2D wave forecast with higher accuracy and efficiency. 展开更多
关键词 Conv2D CNN-BiLSTM-Attention wave forecasting significant wave height TYPHOON
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面向ADS-B信号辐射源个体识别的轻量化模型设计
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作者 王艺卉 闫文君 +4 位作者 徐从安 查浩然 桂冠 陈雪梅 葛亮 《太赫兹科学与电子信息学报》 2023年第9期1100-1108,共9页
针对辐射源个体识别高精确度、轻量化、实时性的现实应用需求,提出了面向广播式自动相关监测(ADS-B)信号辐射源个体识别的轻量化模型设计方法。根据信号数据特点进行解码处理,并对不均衡样本进行权重调节,改善样本质量;通过分组卷积获... 针对辐射源个体识别高精确度、轻量化、实时性的现实应用需求,提出了面向广播式自动相关监测(ADS-B)信号辐射源个体识别的轻量化模型设计方法。根据信号数据特点进行解码处理,并对不均衡样本进行权重调节,改善样本质量;通过分组卷积获取不同维度的细微特征,与初始特征拼接,实现多维互补特征融合,并联同步进行提高识别效率。利用Ghost bottleneck结构实现网络模型压缩与跨层连接,在融合多维特征的同时节省计算资源。实验结果表明,本文算法结构精简,计算量低,识别率达到95.2%,并在不同容量的样本识别中效果稳定。本文算法较好地平衡了辐射源个体识别精确度、轻量化与高时效的需求。 展开更多
关键词 辐射源个体识别 Conv2D层 Ghost bottleneck结构 轻量化设计
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