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Feature Extraction by Multi-Scale Principal Component Analysis and Classification in Spectral Domain 被引量:2
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作者 Shengkun Xie Anna T. Lawnizak +1 位作者 Pietro Lio Sridhar Krishnan 《Engineering(科研)》 2013年第10期268-271,共4页
Feature extraction of signals plays an important role in classification problems because of data dimension reduction property and potential improvement of a classification accuracy rate. Principal component analysis (... Feature extraction of signals plays an important role in classification problems because of data dimension reduction property and potential improvement of a classification accuracy rate. Principal component analysis (PCA), wavelets transform or Fourier transform methods are often used for feature extraction. In this paper, we propose a multi-scale PCA, which combines discrete wavelet transform, and PCA for feature extraction of signals in both the spatial and temporal domains. Our study shows that the multi-scale PCA combined with the proposed new classification methods leads to high classification accuracy for the considered signals. 展开更多
关键词 multi-scale Principal Component Analysis Discrete WAVELET TRANSFORM feature extraction Signal CLASSIFICATION Empirical CLASSIFICATION
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Research on Feature Extraction of Composite Pseudocode Phase Modulation-Carrier Frequency Modulation Signal Based on PWD Transform
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作者 李明孜 赵惠昌 《Defence Technology(防务技术)》 SCIE EI CAS 2008年第4期281-284,共4页
The identification features of composite pseudocode phase modulation and carry frequency modulation signal include pseudocode and modulation frequency. In this paper,PWD is used to extract these features. First,the fe... The identification features of composite pseudocode phase modulation and carry frequency modulation signal include pseudocode and modulation frequency. In this paper,PWD is used to extract these features. First,the feature of pseudocode is extracted using the amplitude output of PWD and the correlation filter technology. Then the feature of frequency modulation is extracted by way of PWD analysis on the signal processed by anti-phase operation according to the extracted feature of pseudo code,i.e. position information of changed abruptly point of phase. The simulation result shows that both the features of frequency modulation and phase change position caused by the pseudocode phase modulation can be extracted effectively for SNR=3 dB. 展开更多
关键词 信号接收系统 信号分析 侦察 电子对抗
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Marine organism classification method based on hierarchical multi-scale attention mechanism
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作者 XU Haotian CHENG Yuanzhi +1 位作者 ZHAO Dong XIE Peidong 《Optoelectronics Letters》 2025年第6期354-361,共8页
We propose a hierarchical multi-scale attention mechanism-based model in response to the low accuracy and inefficient manual classification of existing oceanic biological image classification methods. Firstly, the hie... We propose a hierarchical multi-scale attention mechanism-based model in response to the low accuracy and inefficient manual classification of existing oceanic biological image classification methods. Firstly, the hierarchical efficient multi-scale attention(H-EMA) module is designed for lightweight feature extraction, achieving outstanding performance at a relatively low cost. Secondly, an improved EfficientNetV2 block is used to integrate information from different scales better and enhance inter-layer message passing. Furthermore, introducing the convolutional block attention module(CBAM) enhances the model's perception of critical features, optimizing its generalization ability. Lastly, Focal Loss is introduced to adjust the weights of complex samples to address the issue of imbalanced categories in the dataset, further improving the model's performance. The model achieved 96.11% accuracy on the intertidal marine organism dataset of Nanji Islands and 84.78% accuracy on the CIFAR-100 dataset, demonstrating its strong generalization ability to meet the demands of oceanic biological image classification. 展开更多
关键词 integrate information different scales hierarchical multi scale attention lightweight feature extraction focal loss efficientnetv marine organism classification oceanic biological image classification methods convolutional block attention module
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A NEW DIGITAL MODULATION RECOGNITION METHOD USING FEATURES EXTRACTED FROM GAR MODEL PARAMETERS 被引量:3
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作者 Lu Mingquan Xiao Xianci Li Lemin (University of Electronic Science and Technology of China, Chengdu 610054) 《Journal of Electronics(China)》 1999年第3期244-250,共7页
Based on the features extracted from generalized autoregressive (GAR) model parameters of the received waveform, and the use of multilayer perceptron(MLP) neural network classifier, a new digital modulation recognitio... Based on the features extracted from generalized autoregressive (GAR) model parameters of the received waveform, and the use of multilayer perceptron(MLP) neural network classifier, a new digital modulation recognition method is proposed in this paper. Because of the better noise suppression ability of the GAR model and the powerful pattern classification capacity of the MLP neural network classifier, the new method can significantly improve the recognition performance in lower SNR with better robustness. To assess the performance of the new method, computer simulations are also performed. 展开更多
关键词 modulATION RECOGNITION GAR model feature extraction NEURAL network CLASSIFIER
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A High Resolution Convolutional Neural Network with Squeeze and Excitation Module for Automatic Modulation Classification 被引量:1
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作者 Duan Ruifeng Zhao Yuanlin +3 位作者 Zhang Haiyan Li Xinze Cheng Peng Li Yonghui 《China Communications》 SCIE CSCD 2024年第10期132-147,共16页
Automatic modulation classification(AMC) technology is one of the cutting-edge technologies in cognitive radio communications. AMC based on deep learning has recently attracted much attention due to its superior perfo... Automatic modulation classification(AMC) technology is one of the cutting-edge technologies in cognitive radio communications. AMC based on deep learning has recently attracted much attention due to its superior performances in classification accuracy and robustness. In this paper, we propose a novel, high resolution and multi-scale feature fusion convolutional neural network model with a squeeze-excitation block, referred to as HRSENet,to classify different kinds of modulation signals.The proposed model establishes a parallel computing mechanism of multi-resolution feature maps through the multi-layer convolution operation, which effectively reduces the information loss caused by downsampling convolution. Moreover, through dense skipconnecting at the same resolution and up-sampling or down-sampling connection at different resolutions, the low resolution representation of the deep feature maps and the high resolution representation of the shallow feature maps are simultaneously extracted and fully integrated, which is benificial to mine signal multilevel features. Finally, the feature squeeze and excitation module embedded in the decoder is used to adjust the response weights between channels, further improving classification accuracy of proposed model.The proposed HRSENet significantly outperforms existing methods in terms of classification accuracy on the public dataset “Over the Air” in signal-to-noise(SNR) ranging from-2dB to 20dB. The classification accuracy in the proposed model achieves 85.36% and97.30% at 4dB and 10dB, respectively, with the improvement by 9.71% and 5.82% compared to LWNet.Furthermore, the model also has a moderate computation complexity compared with several state-of-the-art methods. 展开更多
关键词 automatic modulation classification deep learning feature squeeze-and-excitation HIGH-RESOLUTION multi-scale
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Multi-Scale Mixed Attention Tea Shoot Instance Segmentation Model 被引量:1
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作者 Dongmei Chen Peipei Cao +5 位作者 Lijie Yan Huidong Chen Jia Lin Xin Li Lin Yuan Kaihua Wu 《Phyton-International Journal of Experimental Botany》 SCIE 2024年第2期261-275,共15页
Tea leaf picking is a crucial stage in tea production that directly influences the quality and value of the tea.Traditional tea-picking machines may compromise the quality of the tea leaves.High-quality teas are often... Tea leaf picking is a crucial stage in tea production that directly influences the quality and value of the tea.Traditional tea-picking machines may compromise the quality of the tea leaves.High-quality teas are often handpicked and need more delicate operations in intelligent picking machines.Compared with traditional image processing techniques,deep learning models have stronger feature extraction capabilities,and better generalization and are more suitable for practical tea shoot harvesting.However,current research mostly focuses on shoot detection and cannot directly accomplish end-to-end shoot segmentation tasks.We propose a tea shoot instance segmentation model based on multi-scale mixed attention(Mask2FusionNet)using a dataset from the tea garden in Hangzhou.We further analyzed the characteristics of the tea shoot dataset,where the proportion of small to medium-sized targets is 89.9%.Our algorithm is compared with several mainstream object segmentation algorithms,and the results demonstrate that our model achieves an accuracy of 82%in recognizing the tea shoots,showing a better performance compared to other models.Through ablation experiments,we found that ResNet50,PointRend strategy,and the Feature Pyramid Network(FPN)architecture can improve performance by 1.6%,1.4%,and 2.4%,respectively.These experiments demonstrated that our proposed multi-scale and point selection strategy optimizes the feature extraction capability for overlapping small targets.The results indicate that the proposed Mask2FusionNet model can perform the shoot segmentation in unstructured environments,realizing the individual distinction of tea shoots,and complete extraction of the shoot edge contours with a segmentation accuracy of 82.0%.The research results can provide algorithmic support for the segmentation and intelligent harvesting of premium tea shoots at different scales. 展开更多
关键词 Tea shoots attention mechanism multi-scale feature extraction instance segmentation deep learning
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Study on Image Recognition Algorithm for Residual Snow and Ice on Photovoltaic Modules 被引量:1
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作者 Yongcan Zhu JiawenWang +3 位作者 Ye Zhang Long Zhao Botao Jiang Xinbo Huang 《Energy Engineering》 EI 2024年第4期895-911,共17页
The accumulation of snow and ice on PV modules can have a detrimental impact on power generation,leading to reduced efficiency for prolonged periods.Thus,it becomes imperative to develop an intelligent system capable ... The accumulation of snow and ice on PV modules can have a detrimental impact on power generation,leading to reduced efficiency for prolonged periods.Thus,it becomes imperative to develop an intelligent system capable of accurately assessing the extent of snow and ice coverage on PV modules.To address this issue,the article proposes an innovative ice and snow recognition algorithm that effectively segments the ice and snow areas within the collected images.Furthermore,the algorithm incorporates an analysis of the morphological characteristics of ice and snow coverage on PV modules,allowing for the establishment of a residual ice and snow recognition process.This process utilizes both the external ellipse method and the pixel statistical method to refine the identification process.The effectiveness of the proposed algorithm is validated through extensive testing with isolated and continuous snow area pictures.The results demonstrate the algorithm’s accuracy and reliability in identifying and quantifying residual snow and ice on PV modules.In conclusion,this research presents a valuable method for accurately detecting and quantifying snow and ice coverage on PV modules.This breakthrough is of utmost significance for PV power plants,as it enables predictions of power generation efficiency and facilitates efficient PV maintenance during the challenging winter conditions characterized by snow and ice.By proactively managing snow and ice coverage,PV power plants can optimize energy production and minimize downtime,ensuring a sustainable and reliable renewable energy supply. 展开更多
关键词 Photovoltaic(PV)module residual snow and ice snow detection feature extraction image processing
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A Lightweight Network with Dual Encoder and Cross Feature Fusion for Cement Pavement Crack Detection
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作者 Zhong Qu Guoqing Mu Bin Yuan 《Computer Modeling in Engineering & Sciences》 SCIE EI 2024年第7期255-273,共19页
Automatic crack detection of cement pavement chiefly benefits from the rapid development of deep learning,with convolutional neural networks(CNN)playing an important role in this field.However,as the performance of cr... Automatic crack detection of cement pavement chiefly benefits from the rapid development of deep learning,with convolutional neural networks(CNN)playing an important role in this field.However,as the performance of crack detection in cement pavement improves,the depth and width of the network structure are significantly increased,which necessitates more computing power and storage space.This limitation hampers the practical implementation of crack detection models on various platforms,particularly portable devices like small mobile devices.To solve these problems,we propose a dual-encoder-based network architecture that focuses on extracting more comprehensive fracture feature information and combines cross-fusion modules and coordinated attention mechanisms formore efficient feature fusion.Firstly,we use small channel convolution to construct shallow feature extractionmodule(SFEM)to extract low-level feature information of cracks in cement pavement images,in order to obtainmore information about cracks in the shallowfeatures of images.In addition,we construct large kernel atrous convolution(LKAC)to enhance crack information,which incorporates coordination attention mechanism for non-crack information filtering,and large kernel atrous convolution with different cores,using different receptive fields to extract more detailed edge and context information.Finally,the three-stage feature map outputs from the shallow feature extraction module is cross-fused with the two-stage feature map outputs from the large kernel atrous convolution module,and the shallow feature and detailed edge feature are fully fused to obtain the final crack prediction map.We evaluate our method on three public crack datasets:DeepCrack,CFD,and Crack500.Experimental results on theDeepCrack dataset demonstrate the effectiveness of our proposed method compared to state-of-the-art crack detection methods,which achieves Precision(P)87.2%,Recall(R)87.7%,and F-score(F1)87.4%.Thanks to our lightweight crack detectionmodel,the parameter count of the model in real-world detection scenarios has been significantly reduced to less than 2M.This advancement also facilitates technical support for portable scene detection. 展开更多
关键词 Shallow feature extraction module large kernel atrous convolution dual encoder lightweight network crack detection
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Ship recognition based on HRRP via multi-scale sparse preserving method
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作者 YANG Xueling ZHANG Gong SONG Hu 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第3期599-608,共10页
In order to extract the richer feature information of ship targets from sea clutter, and address the high dimensional data problem, a method termed as multi-scale fusion kernel sparse preserving projection(MSFKSPP) ba... In order to extract the richer feature information of ship targets from sea clutter, and address the high dimensional data problem, a method termed as multi-scale fusion kernel sparse preserving projection(MSFKSPP) based on the maximum margin criterion(MMC) is proposed for recognizing the class of ship targets utilizing the high-resolution range profile(HRRP). Multi-scale fusion is introduced to capture the local and detailed information in small-scale features, and the global and contour information in large-scale features, offering help to extract the edge information from sea clutter and further improving the target recognition accuracy. The proposed method can maximally preserve the multi-scale fusion sparse of data and maximize the class separability in the reduced dimensionality by reproducing kernel Hilbert space. Experimental results on the measured radar data show that the proposed method can effectively extract the features of ship target from sea clutter, further reduce the feature dimensionality, and improve target recognition performance. 展开更多
关键词 ship target recognition high-resolution range profile(HRRP) multi-scale fusion kernel sparse preserving projection(MSFKSPP) feature extraction dimensionality reduction
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Underwater Image Enhancement Based on Multi-scale Adversarial Network
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作者 ZENG Jun-yang SI Zhan-jun 《印刷与数字媒体技术研究》 CAS 北大核心 2024年第5期70-77,共8页
In this study,an underwater image enhancement method based on multi-scale adversarial network was proposed to solve the problem of detail blur and color distortion in underwater images.Firstly,the local features of ea... In this study,an underwater image enhancement method based on multi-scale adversarial network was proposed to solve the problem of detail blur and color distortion in underwater images.Firstly,the local features of each layer were enhanced into the global features by the proposed residual dense block,which ensured that the generated images retain more details.Secondly,a multi-scale structure was adopted to extract multi-scale semantic features of the original images.Finally,the features obtained from the dual channels were fused by an adaptive fusion module to further optimize the features.The discriminant network adopted the structure of the Markov discriminator.In addition,by constructing mean square error,structural similarity,and perceived color loss function,the generated image is consistent with the reference image in structure,color,and content.The experimental results showed that the enhanced underwater image deblurring effect of the proposed algorithm was good and the problem of underwater image color bias was effectively improved.In both subjective and objective evaluation indexes,the experimental results of the proposed algorithm are better than those of the comparison algorithm. 展开更多
关键词 Underwater image enhancement Generative adversarial network multi-scale feature extraction Residual dense block
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A multi-scale convolutional auto-encoder and its application in fault diagnosis of rolling bearings 被引量:12
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作者 Ding Yunhao Jia Minping 《Journal of Southeast University(English Edition)》 EI CAS 2019年第4期417-423,共7页
Aiming at the difficulty of fault identification caused by manual extraction of fault features of rotating machinery,a one-dimensional multi-scale convolutional auto-encoder fault diagnosis model is proposed,based on ... Aiming at the difficulty of fault identification caused by manual extraction of fault features of rotating machinery,a one-dimensional multi-scale convolutional auto-encoder fault diagnosis model is proposed,based on the standard convolutional auto-encoder.In this model,the parallel convolutional and deconvolutional kernels of different scales are used to extract the features from the input signal and reconstruct the input signal;then the feature map extracted by multi-scale convolutional kernels is used as the input of the classifier;and finally the parameters of the whole model are fine-tuned using labeled data.Experiments on one set of simulation fault data and two sets of rolling bearing fault data are conducted to validate the proposed method.The results show that the model can achieve 99.75%,99.3%and 100%diagnostic accuracy,respectively.In addition,the diagnostic accuracy and reconstruction error of the one-dimensional multi-scale convolutional auto-encoder are compared with traditional machine learning,convolutional neural networks and a traditional convolutional auto-encoder.The final results show that the proposed model has a better recognition effect for rolling bearing fault data. 展开更多
关键词 fault diagnosis deep learning convolutional auto-encoder multi-scale convolutional kernel feature extraction
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Disease Recognition of Apple Leaf Using Lightweight Multi-Scale Network with ECANet 被引量:4
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作者 Helong Yu Xianhe Cheng +2 位作者 Ziqing Li Qi Cai Chunguang Bi 《Computer Modeling in Engineering & Sciences》 SCIE EI 2022年第9期711-738,共28页
To solve the problem of difficulty in identifying apple diseases in the natural environment and the low application rate of deep learning recognition networks,a lightweight ResNet(LW-ResNet)model for apple disease rec... To solve the problem of difficulty in identifying apple diseases in the natural environment and the low application rate of deep learning recognition networks,a lightweight ResNet(LW-ResNet)model for apple disease recognition is proposed.Based on the deep residual network(ResNet18),the multi-scale feature extraction layer is constructed by group convolution to realize the compression model and improve the extraction ability of different sizes of lesion features.By improving the identity mapping structure to reduce information loss.By introducing the efficient channel attention module(ECANet)to suppress noise from a complex background.The experimental results show that the average precision,recall and F1-score of the LW-ResNet on the test set are 97.80%,97.92%and 97.85%,respectively.The parameter memory is 2.32 MB,which is 94%less than that of ResNet18.Compared with the classic lightweight networks SqueezeNet and MobileNetV2,LW-ResNet has obvious advantages in recognition performance,speed,parameter memory requirement and time complexity.The proposed model has the advantages of low computational cost,low storage cost,strong real-time performance,high identification accuracy,and strong practicability,which can meet the needs of real-time identification task of apple leaf disease on resource-constrained devices. 展开更多
关键词 Apple disease recognition deep residual network multi-scale feature efficient channel attention module lightweight network
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RealFuVSR:Feature enhanced real-world video super-resolution
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作者 Zhi LI Xiongwen PANG +1 位作者 Yiyue JIANG Yujie WANG 《Virtual Reality & Intelligent Hardware》 EI 2023年第6期523-537,共15页
Background Recurrent recovery is a common method for video super-resolution(VSR)that models the correlation between frames via hidden states.However,the application of this structure in real-world scenarios can lead t... Background Recurrent recovery is a common method for video super-resolution(VSR)that models the correlation between frames via hidden states.However,the application of this structure in real-world scenarios can lead to unsatisfactory artifacts.We found that in real-world VSR training,the use of unknown and complex degradation can better simulate the degradation process in the real world.Methods Based on this,we propose the RealFuVSR model,which simulates real-world degradation and mitigates artifacts caused by the VSR.Specifically,we propose a multiscale feature extraction module(MSF)module that extracts and fuses features from multiple scales,thereby facilitating the elimination of hidden state artifacts.To improve the accuracy of the hidden state alignment information,RealFuVSR uses an advanced optical flow-guided deformable convolution.Moreover,a cascaded residual upsampling module was used to eliminate noise caused by the upsampling process.Results The experiment demonstrates that RealFuVSR model can not only recover high-quality videos but also outperforms the state-of-the-art RealBasicVSR and RealESRGAN models. 展开更多
关键词 Video super-resolution Deformable convolution Cascade residual upsampling Second-order degradation multi-scale feature extraction
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基于持续同调算法的光伏热斑识别与分类方法 被引量:1
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作者 孙海蓉 张洪玮 +1 位作者 唐振超 周黎辉 《太阳能学报》 北大核心 2025年第5期285-292,共8页
针对光伏组件中红外热斑的识别及分类需训练样本数量较大以及准确率还有待提高的问题,提出一种基于持续同调算法与卷积神经网络相结合的热斑识别方法。首先使用拓扑数据分析中的持续同调算法,将红外热图像中RGB三通道上的数值映射到三... 针对光伏组件中红外热斑的识别及分类需训练样本数量较大以及准确率还有待提高的问题,提出一种基于持续同调算法与卷积神经网络相结合的热斑识别方法。首先使用拓扑数据分析中的持续同调算法,将红外热图像中RGB三通道上的数值映射到三维坐标系形成三维点云,然后进行持续同调计算,预先提取出图片内部所包含的拓扑特征,再将提取出的特征向量化处理后以固定的顺序排列,映射到图像的像素中去,并与图片的亮度及对比度特征相结合,最后将处理后的图像数据输入到调整后的LeNet-5卷积神经网络模型中,实现对光伏红外热斑的分类识别,并通过混淆矩阵计算各项性能指标,以评估模型的性能。实验结果表明,该模型有效地提取出隐藏在图像内部的高维拓扑特征,并与其他特征进行有利地互补结合,解决图像数据无法直接输入到持续同调算法中以及高维度拓扑特征无法直接作为深度学习模型输入的问题,同时提高了光伏红外热斑的分类识别准确率,且显著减少了所需的计算资源。 展开更多
关键词 光伏组件 特征提取 卷积神经网络 拓扑数据分析 持续同调 光伏热斑
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面向杂乱场景的机械臂抓取位姿预测方法
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作者 李轩青 陈燕 《机电工程》 北大核心 2025年第6期1185-1192,共8页
针对复杂场景下机器人抓取智能化程度及抓取精度不足等问题,提出了一种新颖的机器人抓取位姿预测方法,即实时抓取网络(RGN)。首先,引入KPConv作为骨干网络,将其用于超点与密集点的特征提取,提出了一种新颖的几何特征计算方法,并利用交... 针对复杂场景下机器人抓取智能化程度及抓取精度不足等问题,提出了一种新颖的机器人抓取位姿预测方法,即实时抓取网络(RGN)。首先,引入KPConv作为骨干网络,将其用于超点与密集点的特征提取,提出了一种新颖的几何特征计算方法,并利用交叉注意力机制实现了多源特征的融合目的;然后,提出了区域关联特征提取模块,借助于几何特征信息进行了区域划分,通过多层感知机进一步完成了抓取位姿的预测,利用抓取系统运动链将夹爪位姿映射到了机械臂关节角特征上,控制机械臂完成了抓取;最后,引入了多样性损失函数,并将其与基线模型进行了对比,利用GraspNet-1Billion数据集和Cornell数据集开展了复杂场景下机械臂抓取性能的测试实验。研究结果表明:采用RGN方法可使抓取预测精度得到大幅提升,最大提升幅度达78.2%;将传统手工特征与深度学习相融合,对机械臂抓取位姿预测精度的提升起到了关键作用,这一规律可为构建良好的机械臂抓取模型提供具体参考方向。 展开更多
关键词 机器人抓取 抓取位姿估计 实时抓取网络 点云 深度学习 特征提取模块 交叉注意力模块
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一种自适应残差卷积自编码网络及其故障诊断应用
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作者 潘天成 陈龙 +1 位作者 蒲春雷 陈志强 《机电工程》 北大核心 2025年第3期529-538,共10页
针对传统卷积自编码器(CAE)会将不同故障产生的相似信号进行相同的非线性变换,导致故障诊断准确率下降的问题,提出了一种自适应残差卷积自编码网络(ARCAE),并将其应用于滚动轴承故障诊断中。首先,在残差模块的基础上,引入了自适应参数... 针对传统卷积自编码器(CAE)会将不同故障产生的相似信号进行相同的非线性变换,导致故障诊断准确率下降的问题,提出了一种自适应残差卷积自编码网络(ARCAE),并将其应用于滚动轴承故障诊断中。首先,在残差模块的基础上,引入了自适应参数化修正线性单元(APReLU),建立了自适应残差模块(ARM),ARM可以对相似的输入特征进行自适应非线性变换,避免了特征的错误识别;其次,在CAE中嵌入多级ARM,构建了ARCAE,增加了CAE的深度,提取了更具鉴别性的深层次特征,同时有效防止了网络加深而造成的性能退化;最后,基于ARCAE建立了针对一维信号的故障诊断新方法,将其应用于无监督滚动轴承故障诊断中,并通过两个不同类型的实验,对上述方法的有效性进行了验证。研究结果表明:在恒定转速工况下,ARCAE的诊断准确率最高,平均准确率达到了97.05%,且标准差仅为0.007,远低于其他几种传统CAE网络;在变转速工况下,ARCAE模型诊断准确率仍然是最高的,平均准确率达到了93.25%,由此说明ARCAE具有较高的特征提取能力和分类准确率;此外,变转速工况下,由于转速变化导致不同状态的振动信号特征差异变大,诊断难度加大,但与其他几种传统CAE网络相比,ARCAE诊断准确率下降最少,仅为5.37%,说明ARCAE具有更强的鲁棒性和稳定性。 展开更多
关键词 滚动轴承 自适应残差卷积自编码网络 自适应参数化修正线性单元 自适应残差模块 无监督故障诊断 特征提取
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基于MCNN-APReLU的滚动轴承故障诊断方法
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作者 赵小强 郭海科 《兰州理工大学学报》 北大核心 2025年第5期37-45,共9页
针对传统滚动轴承故障诊断方法因特征提取不充分而导致在变噪声、变工况和变负荷情况下准确率不佳,提出了多通道卷积神经网络的滚动轴承故障诊断方法.首先,设计了多通道的密集连接模块,加强了不同卷积层之间的信息联系,有效提取了故障信... 针对传统滚动轴承故障诊断方法因特征提取不充分而导致在变噪声、变工况和变负荷情况下准确率不佳,提出了多通道卷积神经网络的滚动轴承故障诊断方法.首先,设计了多通道的密集连接模块,加强了不同卷积层之间的信息联系,有效提取了故障信息;然后,设计了包含自适应参数化修正线性单元激活函数的空洞卷积模块,给每个通道赋予不同的权重系数,提取更重要、更关键的信息;最后,使用Inception模块进行特征降维并进一步提取故障特征,通过多分类函数实现滚动轴承的故障诊断.同时,使用美国凯斯西储大学轴承数据集和东南大学变速箱数据集进行验证.结果表明:平均准确率在变噪声实验中为98.5%,在变负荷实验中为91.7%~97.7%,在变工况实验中为87.79%~96.71%;使用变速箱数据集时故障诊断准确率高达99.84%.与其他滚动轴承故障诊断方法相比,该方法对于不同数据集以及变噪声、变负荷和变工况条件下准确率更高且泛化能力更好. 展开更多
关键词 特征提取 密集连接 卷积神经网络 Inception模块 识别分类
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基于MAFM-YOLOv8的学生课堂表现检测
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作者 莫建文 姜贵昀 +1 位作者 袁华 梁豪昌 《计算机工程与设计》 北大核心 2025年第6期1825-1831,共7页
针对智慧教室场景中学生课堂表现检测遇到的目标尺度大小不一、容易出现遮挡、目标密集度高、重叠以及小目标等问题,提出一种基于MAFM-YOLOv8的学生课堂表现检测模型。提出一个多尺度自适应特征提取模块,增强模型对不同尺度特征信息的... 针对智慧教室场景中学生课堂表现检测遇到的目标尺度大小不一、容易出现遮挡、目标密集度高、重叠以及小目标等问题,提出一种基于MAFM-YOLOv8的学生课堂表现检测模型。提出一个多尺度自适应特征提取模块,增强模型对不同尺度特征信息的自适应特征提取能力,用深度可分离卷积代替普通卷积,减少模块中卷积的计算量;采用高效多尺度注意力模块,增强模型对小目标的特征提取能力;采用WIOU损失函数来增强模型在类别不均衡数据集上的训练效果,提升检测性能。实验结果表明,改进YOLOv8算法在学生课堂表现检测中mAP50达到了87.2%,相比原模型提升了3.2%,验证该方法可以有效提高检测精度。 展开更多
关键词 智慧教室 学生课堂表现检测 MAFM-YOLOv8 多尺度自适应特征提取模块 深度可分离卷积 高效多尺度注意力 WIOU损失函数
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基于频率与注意力机制的图像去雾算法
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作者 王军 孟儒君 程勇 《计算机系统应用》 2025年第1期161-170,共10页
由于大气雾和气溶胶的存在,图像能见度显著下降且色彩失真,给高级图像识别带来极大困难.现有的图像去雾算法常存在过度增强、细节丢失和去雾不充分等问题.针对过度增强和去雾不充分的问题,本文提出了一种基于频率和注意力机制的图像去... 由于大气雾和气溶胶的存在,图像能见度显著下降且色彩失真,给高级图像识别带来极大困难.现有的图像去雾算法常存在过度增强、细节丢失和去雾不充分等问题.针对过度增强和去雾不充分的问题,本文提出了一种基于频率和注意力机制的图像去雾算法(frequency and attention mechanism of the image dehazing network,FANet).该算法采用编码器-解码器结构,通过构建双分支频率提取模块获取全局和局部的高低频信息.构建频率融合模块调整高低频信息的权重占比,并在下采样过程中引入附加通道-像素模块和通道-像素注意力模块,以优化去雾效果.实验结果显示,FANet在SOTS-indoor数据集上的PSNR和SSIM分别为40.07 dB和0.9958,在SOTS-outdoor数据集上分别为39.77 dB和0.9958.同时,该算法也在HSTS和Haze4k测试集上取得了不错的结果,与其他去雾算法相比有效缓解了颜色失真和去雾不彻底等问题. 展开更多
关键词 图像去雾 双分支频率提取模块 注意力机制 特征融合 编码器-解码器结构
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基于电−振信号联合的电动机故障诊断研究
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作者 惠阿丽 周睿香 +2 位作者 韦鹏 魏礼鹏 荣相 《工矿自动化》 北大核心 2025年第10期114-122,共9页
针对煤矿井下电动机复杂工况下单一信号(电流、振动)故障诊断精度有限、多故障并存导致识别困难的问题,基于机电耦合特性及多传感器信息互补性,提出基于电−振信号联合的电动机故障诊断方法。分别对电动机电流信号和振动信号在时域、频... 针对煤矿井下电动机复杂工况下单一信号(电流、振动)故障诊断精度有限、多故障并存导致识别困难的问题,基于机电耦合特性及多传感器信息互补性,提出基于电−振信号联合的电动机故障诊断方法。分别对电动机电流信号和振动信号在时域、频域和时频域内捕获故障信息,在通道维度上融合生成包含多域信息的特征彩色图像,丰富故障表征信息。构建了一种嵌入改进卷积块注意力模块(ICBAM)的双通道残差网络(DCResNet)模型ICBAM−DCResNet,通过多层残差块和ICBAM的注意力机制,挖掘图像样本的深层特征,最后进行融合并实现分类,实现电−振信号联合的故障诊断。对比实验结果表明,多域融合相比单一分析域诊断精度更高,ICBAM−DCResNet模型比深度残差网络(ResNet)模型性能更好,对信号样本的特征提取能力更强。在公开数据集上的实验结果表明,基于电−振信号联合的电动机故障诊断方法的准确率达99.8%,对转子故障和轴承故障均能取得不错的识别效果,泛化性较好。 展开更多
关键词 电动机故障诊断 电流信号 振动信号 多域特征提取 双通道残差网络 卷积块注意力模块
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