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Most of the Encryption-then-Compression (ETC) methods can only obtain several limited fixed compression ratios. However, arbitrary encryption compression ratios instead of limited fixed compression ratios are more suitable for practical requirements. To this end, this paper proposed a lossy compression algorithm for encrypted color images with arbitrary compression ratios. It combines the uniform and random downsampling to compress the encrypted images, obtaining arbitrary compression ratios of an encrypted image. The receiver receives the compressed sequence of the encrypted image and obtains the decrypted image by decompression and decryption. The proposed scheme then characterizes the lossy reconstruction of the original image from the decrypted image as an optimization problem with the downsampling compression-based constraint. This scheme designs a convolutional neural network-based image reconstruction model for lossy ETC to resolve this problem, which is denoted the ETC-oriented Reconstruction Network (ETRN). ETRN consists of shallow feature extraction (SFE), residual in residual (RIR), residual content supplementation (RCS), and down-sampling constraint (DC). The experimental simulation results show that the encrypted color image lossy compression algorithm proposed in this paper can obtain excellent compression and reconstruction performance, which fully demonstrates the feasibility and effectiveness of this method. [ABSTRACT FROM AUTHOR]

To solve the problem of inaccurate description and unreliable relation inference in group activity recognition, this paper focused on constructing a scene relationship graph for three aspects: individual, group, and scene, and proposed a scene relationship graph network（SRGN） for group activity recognition. This method included a feature extraction module, a scene relation graph inference module, and a classification module. The feature extraction module extracted individual features, group features, and scene features by convolutional neural network. To fully explore the impact of scene on individual and group descriptions, the scene relation graph inference module learnt individual features and group features by building individual-scene and group-scene relationship graphs in a two-branch framework. Scene graph inference took into account the influence of individual on group and introduced a cross-branch module. It used the classification module to classify individual features and group features for prediction. The experimental results show that the group recognition accuracy of the proposed method on volleyball and collective activity data sets is improved by 1. 1% and 0. 5%,respectively. It verifies the validity of the scene graph in describing individual feature and group feature. [ABSTRACT FROM AUTHOR]

To solve the problem of combustion state recognition in solid oxide fuel cell (SOFC) combustor, this paper proposed a combustion state recognition method based on attention mechanism and image feature pyramid. The method adopted the adaptive gamma correction with weighting distribution (AGCWD) to standardize the input images. It combined two single full connections with 1×1 convolution to replace the squeeze and excitation structure, and proposed a hybrid attention structure combined with spatial attention structure to enhance the ability of feature extraction. To provide multi-scale information communication capability, it constructed the multi-scale bidirectional fusion pyramid by means of bidirectional computation and multi-scale fusion. The experimental results show that the proposed method reaches 99.22% accuracy under the premise of 3.98 M parameters and 397 M floating point operations (FLOPs), and effectively identifies the combustion state in SOFC combustor. [ABSTRACT FROM AUTHOR]

Action recognition (AR) is a hot research area in computer vision field, and has an extensive application prospect for security monitoring, autopilot, production safety etc. Firstly, this paper analysed the connotation and denotation of AR and put forward the technical challenges; Secondly, the paper analysed and compared the working principles of AR from three aspects: time feature extraction, efficient optimization and long-term feature capture; Thirdly, in order to select suitable AR models for different application scenarios, this paper compared the performance characterization of 43 benchmark AR methods in recent ten years based on UCF101, HMDB51, Something-Something and Kinetics400 data sets. Finally, this paper pointed out the future development direction of AR field, and the research results can provide theoretical reference and technical support for video feature extraction and visual content understanding. [ABSTRACT FROM AUTHOR]

In image retrieval based on deep hashing, to solve the problems of low feature extraction efficiency in convolutional neural networks (CNN ) and underutilization of feature correlation, this paper proposed a novel method combining sparse difference network and multi-supervised hashing( SDNMSH ), and used it for efficient image retrieval. SDNMSH took pairs of images as training inputs, and guided hash codes learning through an elaborately designed sparse difference convolutional neural network and a supervised hash function. The sparse difference convolutional layer and the vanilla convolutional layer composed the sparse difference convolutional neural network. The sparse difference convolutional layer could quickly extract rich feature information, to achieve efficient feature extraction of the entire network. At the same time, in order to make full use of the pairwise correlation of semantic information and features, so as to promote the feature information extracted by the network to be more effectively transformed into discriminative hash codes, and then to achieve efficient image retrieval by using SDNMSH, this paper adopted a multi-supervised hash( MSH) function and designed an objective function for this purpose. Extensive experimental results on three widely used datasets MNIST,CIFAR-10 and NUS-WIDE show that SDNMSH achieves better retrieval performance, compared with the state-of-the-arts. [ABSTRACT FROM AUTHOR]

In order to accurately predict the short-term passenger flow of urban rail transit for multiple stations, this paper proposed a deep learning model, SAE-ConvLSTM, combining convolutional long short-term memory ( ConvLSTM) and stack autoencoder (SAE) . This paper considered thirteen external factors related to passenger flow, whose features would be extracted by SAE with successive layers and thus obtain more representative features. It proposed ConvLSTM to extract spatiotemporal features of passenger flow, which was combined with the resulting external factors to predict short-term passenger flow of multiple stations simultaneously. And it developed latent action Monte Carlo tree search ( LA-MCTS) to optimize the parameters of SAE. Compared with genetic algorithm( GA), particle swarm optimization ( PSO), simulated annealing algorithm (SA) and tabu search (TS), LA-MCTS performed best in terms of effect and efficiency. This paper conducted extensive experiments. The results show that SAE-ConvLSTM works better than shallow machine learning model-back propagation neural network ( BPNN), support vector regression mode(SVR),autoregressive integrated moving average model ( ARIMA ),and deep learning modellong and short time memory network ( LSTM), convolutional neural network (CNN) and Conv LSTM without external features, ConvLSTM external features without SAE, CNN + LSTM and CNN + LSTM with external features, in terms of root mean square errors ( RMSE), mean absolute errors ( MAE) and mean absolute percentage errors ( MAPE), and the goodness of fit ( R² ) . [ABSTRACT FROM AUTHOR]

Mild cognitive decline is the early stage of Alzheimer's disease, and the feature extraction and classification of mild cognitive decline using EEG signals is an important method for diagnosing mild cognitive decline. In the automatic detection technology of mild cognitive decline based on electroencephalogram artificial intelligence, the existing research only extracted a certain feature in the electroencephalogram signal or simply concatenates multiple features, which caused these methods to fail to well consider the correlation between different features and it would cause the problem of dimensional disaster. This paper proposed a convolutional neural network based automatic detection algorithm for resting state electroencephalogram data of mild cognitive decline. By extracting the power spectrum and brain network features of the electroencephalogram, it fused the two features by matrix operation, and designed a convolutional neural network to classify the fused features. This method achieves a high accuracy rate on the data set collected by a hospital in Shanghai. In addition, by inputting different subsets of the feature set, this method found the few groups of features that contribute the most to mild cognitive decline, thereby it also had a certain interpretability. Experiments on the dataset of this paper, it p roves the advantages of the power brain network for the automatic diagnosis of mild cognitive decline. [ABSTRACT FROM AUTHOR]

Most of the existing steganalysis methods have weak generalization ability and cannot effectively detect unknown steganalysis algorithms, which makes the accuracy of their classification greatly reduced in the practical application process. To solve this problem, this paper proposed an image steganalysis method based on group convolution and snapshot ensembling（Snapshot Ensembling steganalysis network, SENet）. Firstly, residual convolution block and group convolution block are used to extract the features of the image. Secondly, the model with the best performance is obtained as the snapshot model in each training period. Finally, the selected snapshot models are integrated to classify the images. This method uses the techniques of group convolution and snapshot ensembling to avoid the high training cost of traditional integration methods and the limited generalization ability of a single classifier. Experimental results show that this method can improve the accuracy of steganographic analysis model, and can effectively classify when the training set and test set are mismatched, and has high model generalization ability. [ABSTRACT FROM AUTHOR]

The existing aspect-based sentiment analysis models ignore the syntactic relationship between words and fail to extract targeted semantic information. To alleviate the problem, this paper proposed an aspect-based sentiment analysis model to focus on local contextual features. The core idea was to construct local context weighted adjacency graph and dynamic weighting method, and generated aspect word features focusing on local context information through graph convolutional neural network. Specifically, the model adopted the local context dynamic weighting method to increase the attention to the local context during the feature extraction process. Secondly, it assigned weights to the context nodes based on the syntactic dependency relationship, and constructed an adjacency graph for the local context weighting. Finally, under the influence of the multi-layer graph convolutional neural network, it continuously extracted the aspect word features focusing on the local context information. The experimental results shows that, compared with ASGCN, the macro-F1 value on the restaurant and laptop datasets increase by 1.76% and 1.12%, respectively. With the local context weighting, local feature focusing can help to improve the classification effect. [ABSTRACT FROM AUTHOR]

Aiming at the low accuracy of timing synchronization problem in orthogonal frequency division multiplexing (OFDM) system due to the multipath interference, this paper proposed a 1-D CNN-based two-stage timing synchronization method for OFDM systems. In the first stage, it employed the classical cross-correlation method, which realized the initial extraction of path features and thus captured the auxiliary synchronization point of the timing synchronization according to the distinguishable paths. Based on the captured auxiliary synchronization point, it developed the 1-D CNN network for learning timing offset of second stage. Finally, it estimated the timing offset by combining the processes during two stages. Compared with the compressed sensing-based synchronization method and the extreme learning machine-based synchronization method, the two-stage timing synchronization method for OFDM systems investigated improves the accuracy of timing synchronization, while effectively reducing the computational complexity and processing delay. [ABSTRACT FROM AUTHOR]

Rain streaks and fog brought by rain can degrade the quality of images taken outdoors. In order to remove the in-fluence of rain and fog on images, this paper proposed an image derain method based on rain and fog separation processing and multi-scale convolutional neural network. Firstly, it extracted the rain lines and image details to the high frequency layer using guided filtering, while separated the fog and background information to the low frequency layer. Then it constructed a multi-scale convolutional neural network to remove the rain lines in the high frequency layer, and incorporated multiple dense connection modules into the network to improve the accuracy of feature extraction. Secondly, it constructed a lightweight defogging network with multi-layer feature fusion to remove the fog in the low frequency layer, and used the parameter integration structure to avoid estimation of multiple atmospheric scattering model parameters resulting in sub-optimal solutions. Finally, it combined the processed high and low frequency results to restore a clear image. Tested on several synthetic rain and fog datasets as well as on real natural scene images, the qualitative and quantitative results show that the proposed method removes rain and fog while retaining color information well, and improves the image structure similarity by 0. 02 to 0. 08 and the image peak signal-to-noise ratio by 0. 2 to 3. 5 dB compared to recent algorithms. [ABSTRACT FROM AUTHOR]

In order to solve the problem that the Transformer model cannot apply to mobile devices with limited computational resources due to its huge number of parameters and computational complexity, this paper proposed a mobile-friendly lightweight image recognition network called FuseNet. FuseNet utilized convolutional neural network to extract local feature information and self-attention to excel in modeling global information, and it integrated the features of both local and global representations into a single feature extraction module, which efficiently combined the advantages of the two different structures to achieve a high accuracy with a small model size. Experiments demonstrate that FuseNet with different model sizes can achieve good performance without using pre-training and it can well apply to mobile devices. FuseNet-B achieves 80. 5% accuracy with 14. 8 M parameters on ImageNet-1 K dataset, the performance exceeds the same volume of Transformer models and convolutional neural networks. [ABSTRACT FROM AUTHOR]

In the field of CXR image classification, current studies mostly use convolutional neural network and transfer learning technology. But in the process of rapidly constructing a network without considering the specificity of the CXR image. To solve the above problem, this paper proposed a novel XDense-RC-net. Based on the DenseNet model, this method improved the capability of feature extraction and feature fusion by introducing a new spatial attention mechanism in the densely connected layer, Optimized Transition module of DenseNet by using two different pooling strategies to enhance the noise immunity of the model. XDense-RC-net used the chest X-ray14 (multilabel and 14-class) and COVIDx (single label and 3-class) datasets for validating. In the multi-label classification experiments, the average AUC score reached 0.854, which is 0.109 higher than the benchmark method. In the single-label classification experiments, the average accuracy reached 96.75%, which is 7.75% higher than the baseline model. The results show that XDense-RC-net improves the accuracy of CXR image classification and can generalize to multilabel and single-label classification tasks. [ABSTRACT FROM AUTHOR]

In the large data environment, there are many problems in the parallel deep convolution neural network（DCNN） algorithm, such as excessive data redundancy, slow convolution layer operation and poor convergence of loss function. This paper proposed a parallel deep convolution neural network optimization algorithm based on the Im2 col method. First, the algorithm proposed a parallel feature extraction strategy based on Marr-Hildreth operator to extract target features from data as input of convolution neural network, which can effectively avoid the problem of excessive data redundancy. Secondly, the algorithm designed a parallel model training strategy based on the Im2 col method. The redundant convolution kernel is removed by designing the Mahalanobis distance center value, and the convolution layer operation speed is improved by combining the MapReduce and Im2 col methods. Finally, the algorithm proposed an improved small-batch gradient descent strategy, which eliminates the effect of abnormal data on the batch gradient and solves the problem of poor convergence of the loss function. The experimental results show that IA-PDCNNOA algorithm performs well in deep convolution neural network calculation under large data environment and is suitable for parallel DCNN model training of large datasets. [ABSTRACT FROM AUTHOR]

Objectives: The scale of buildings and their distribution is key indicators to measure the economic and social development of a region. Therefore, it is significant to study the extraction of buildings based on remote sensing images. Existing neural network methods still have shortcomings in the completeness of building extraction and the accuracy of building edges. To solve the above problems, this paper proposes a multi-level feature fusion network (MFFNet) based on high-resolution images. Methods: Firstly, we use edge detection operators to improve the ability of the network to recognize the boundaries of buildings. Secondly, we use a multi-path convolution fusion module to extract building features from multiple dimensions, and introduce a large receptive field convolution module to break through feature extraction. The process is limited by the size of the receptive field. After fusing the extracted features, the convolutional attention module is used to compress them, and the global features are further mined by pyramid pooling, so as to achieve high-precision extraction of buildings. Results: The current mainstream UNet, pyramid scene parsing network (PSPNet),multi attending path neural network (MAPNet) and multiscale-feature fusion deep neural networks with dilated convolution (MDNNet) are used as the comparison methods, and we use Wuhan University Aerial Image Dataset, Satellite Dataset II (East Asia) and Inria Aerial Image Dataset as experimental data for testing. Compared with the other four methods, MFFNet improves intersection over union, precision, recall, F1-score and mean average precision by 1.53%, 2.65%, 2.41%, 3.32% and 1.19% on average, achieves a better effect. Conclusions: MFFNet not only accurately captures the detail features of buildings, but also strengthens the extraction and utilization of global features. It has better ex‐ traction effect on large buildings and buildings in complex environment. [ABSTRACT FROM AUTHOR]

The research in 3D human pose estimation from 2D images has achieved great success in recent years. However, the performance of existing 3D human pose estimation methods may degrade significantly in complicated scenarios. To improve the accuracy and robustness of 3D human pose estimation in unconstrained scenarios, this paper proposed ARGP-Pose, a monocular 3D pose estimation framework by exploring the relationship between the joint points of a 3D human pose. To be more specific, the proposed method included a new joint point preprocessing method and a 3D pose estimation network. The preprocessing method enhanced structural features and extracted the relationship among joint points, which were used as input of the following pose estimation network. Also, the proposed network fused local information of each joint point and the global information of the overall pose for rich feature extraction. Additionally, the proposed method extracted the temporal information by using a self-attention module, which achieved further performance boost. Last, for a complex human pose, this method decomposed the prediction of the whole pose into the prediction of each point, which again improved the estimation accuracy for human bodies with complex pose variations. The experimental results obtained on several well-known benchmarking datasets, such as Human3.6M and HumanEva-I, demonstrate the merits and superiority of the proposed method. [ABSTRACT FROM AUTHOR]

When traditional convolutional neural networks are used in mineral species identification, due to their large parameters and the limitations of fixed input image resolution, sufficient computing resources and image preprocessing are required, which are difficult to deploy in actual exploration. For this reason, based on the depth separable convolution,combined with the attention mechanism, this paper constructs a mineral intelligent recognition model through dense connection, and this model can train multi-resolution mineral images. Ex perimental results show that the model's memory usage is only 20 Mb, the verification accuracy and the test accuracy are both higher than 90 %, the classification effect is better than the classic convolutional neural network, and it shows excellent ability to distinguish positive and negative samples. These results show that the proposed model h as fewer parameters and low memory footprint which is suitable for portable devices. This model can successfully identify mineral images with different resolutions, which has good generalization and potential application. [ABSTRACT FROM AUTHOR]

Deep convolutional neural network is widely used in the field of medical image segmentation. In recent years, multi-scale fusion structure is used to improve segmentation network, which often increases the complexity of the model and reduces the training efficiency while improving the accuracy. To solve these problems, this paper proposed a novel segmentation algorithm for WU-Net pulmonary nodules. It improved the U-Net by introducing an improved residual connection module into the original down-sampling coding channel and mean while using the information channel improved by the new dep module to complete feature extraction and feature fusion. In the experiment, it used LUNA16 dataset to train and verify the model. Meanwhile, comparative experiments used some newly segmentation models. In the experiment with scale of nodules, the Dice coefficient and IoU of proposed model can reach 96.72% and 91.78% respectively.F1-score can reach 92.41% after adding 10% negative samples, which is 1.23% higher than UNet3+.In the experiment with scale of lung parenchyma, the Dice coefficient and IoU of proposed model can reach 83.33% and 66.79% respectively, which is 1.35% and 2.53% higher than RU-Net. The training efficiency of WU-Net is the highest, which is 39.6% higher than U-Net spend. The result shows that WU-Net has improved segmentation effects and training efficiency of model as well. [ABSTRACT FROM AUTHOR]

The size of the receptive field of the convolutional neural network is related to the size of the convolution kernel. And the traditional convolution uses a fixed-size convolution kernel, which limits the feature perception ability of the network model. In addition, due to the parameter sharing mechanism of the convolutional neural network, it used the same feature extraction method for all pixels in the spatial region. However, there are differences in the distribution of noise signals and clean speech signals in the noisy spectrogram, especially in the complex noise environment, the general convolution method is difficult to achieve high-quality speech signal feature extraction and choosing. In order to solve the above problems, this paper proposed a multi-scale region adaptive convolution module, which used multi-scale information to improve the feature perception ability of the model and automatically allocated the area adaptive convolution achieve and improved the denoising ability of the model. The experiments on the TIMIT public datasets show that the proposed algorithm has achieved satisfactory results in the metrics of speech quality and intelligibility. [ABSTRACT FROM AUTHOR]

In order to solve the problems of insufficient feature extraction of sEMG end-to-end gesture recognition and low accuracy of multi-gesture recognition, this paper proposed a multi-stream convolutional EMG gesture recognition network model fusing attention mechanism. The proposed model generated sub-myoelectrograms from multi-channel time-domain sEMG through sliding windows and used a multi-stream convolutional neural network to fully extract the semantic features of each sampled channel sEMG, and then aggregated them to obtain rich multi-channel gesture semantic features. At the same time, the proposed model calculated the attention distribution map of semantic features from temporal and feature channel dimensions to strengthen the useful features and weaken the useless features, further improved the accuracy of multi-gesture recognition. The experiment used the Ninapro dataset for training and testing and compared with the mainstream electromyogram recognition model. The experimental results show that the proposed model has better performance in recognition accuracy, which proves the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

In order to improve the correctness and efficiency of tree species recognition, to slow down the occurrence of overfitting, and to enhance the practicality of tree recognition techniques, this paper proposed a tree recognition method based on an improved convolutional neural network. The approach started with compressing the channel in the Xception framework to further exploit the average pool of global feature mapping, and changing the hybrid attention connection to parallel connection. Next, a randomly selected part of the feature map was normalized and re-entered into the neural network after using the attentional feature map cropping method. Finally, ablation experiment was performed and the accuracy of tree species recognition was up to 98.90% in the tree dataset when the learning rate was 0.1 and the iteration was 50 times. The study showed that the proposed improved convolutional neural network had better recognition effect on tree recognition. And the memory of the convolutional neural network architecture was reduced to 133.9 MB and the time consumed was only 458 ms. Using the improved convolutional neural network not only improved the accuracy of tree recognition, but also reduced the time cost. [ABSTRACT FROM AUTHOR]

Facial features play different functions in expressing different emotions, the only use of convolutional neural network for feature extraction and expression recognition of facial features may not lead to enough focus on the key feature information of facial expressions. However, the feature information only extracting from the key parts such as eyes or mouth may not be sufficient. This p aper proposed a facial expression recognition method of tri-path networks based on the optimal convolutional neural network called TP-FER. Based on the convolutional neural network, this method used three input channels to focus on the face, eyes and mouth regions respectively for feature extraction and expression discrimination. Then it used the fusion technology based on the decision layer to make the final decision. At last, it adopted relative majority voting method based on the recognition results of the three channels to obtain the overall optimal recognition rate. This paper conducted several experiments on JCK + dataset and self-built dataset with this method. The results show that the ove rall expression recognition rate is improved in both datasets. This method can make full use of the different channel characteristics that focus on not only the key features such as eyes and mouth but also the comprehensive information of the whole face, and improve the express ion recognition rate effectively. In addition, it can also provide data support for neuropsychological related research. [ABSTRACT FROM AUTHOR]