Despite the widespread application of radio frequency (RF) signal-based human action recognition, traditional solutions can only recognize seen categories and the perception scope is restrained by the limited activity classes. When a novel category emerges, the model needs to be optimized again on additionally collected samples at the cost of computation and labor burden. To address this challenge, we develop the mmZeAR system, which learns semantic knowledge from available vision data as class attributes and then transforms the classification into a matching problem. Specifically, we build the attribute space by fusing the coarse-grained video classification features and fine-grained angle change features of 3D joint skeletons. Then we design an efficient feature extraction backbone named TriSqN, which integrates triple radar heatmaps into the final representations by sufficiently exploring the heterogeneous and complementary characteristics. Finally, a projection network is developed between semantic attributes and radar features to construct indirect relationships between samples and labels. By implementing mmZeAR on millimeter wave (mmWave) radar signal datasets, our extensive experiments have demonstrated its remarkable recognition accuracy in novel category recognition with zero effort and achieved state-of-the-art performance.

As two important contents in WiFi-based action perception, detection and recognition require localizing motion regions from the entire temporal sequences and classifying the corresponding categories. Existing approaches, though yielding reasonably acceptable performances, are suffering from two major drawbacks: heavy empirical dependency and large computational complexity. In order to solve these issues, we develop LiteWiSys in this article, a lightweight system in an end-to-end deep learning manner to simultaneously detect and recognize WiFi-based human actions. Specifically, we assign different attentions on sub-carriers, which are then compressed to reduce noise and information redundancy. Then, LiteWiSys integrates deep separable convolution and a channel shuffle mechanism into a multi-scale convolutional backbone structure. By feature channel split, two network branches are obtained and further trained with a joint loss function for dual tasks. We collect different datasets at multi-scenes and conduct experiments to evaluate the performance of LiteWiSys. In comparison to existing WiFi sensing systems, LiteWiSys achieves promising precision with lower complexity.

With the development of the Industrial Internet of Things (IIoT), the complex traffic generated by large-scale IIoT devices presents challenges for traffic analysis. Most of existing deep learning-based traffic analysis methods use a single flow for classification, resulting in being misled by the irrelevant flow. Thus, it is necessary to use flow sequences for traffic analysis. However, existing models fail to effectively distinguish unimportant flows in flow sequence, which affects the classification performance. To address the aforementioned challenges, we propose a novel traffic classifier called flow transformer to perform traffic analysis with flow sequences, which leverages multihead attention mechanism to strengthen the information interaction between related flows. Besides, the RF-based feature selection method is designed to select the optimal feature combination, avoiding insignificant features from reducing the performance of the classifier. Experimental results on three real-world traffic datasets demonstrate that our method outperforms state-of-the-art methods with a large margin.

Supervising anonymity network is a critical issue in the field of network security, and traditional traffic analysis methods cannot cope with complex anonymity traffic. In recent years, the traffic analysis method based on deep learning has achieved good performance. However, most of the existing studies do not consider the temporal-spatial correlation of the traffic, and only use a single flow for classification. A few works take continuous flows as flow sequence for traffic classification, but they do not distinguish the different importance of each flow. To tackle this issue, we propose a novel flow-based traffic classifier called FLOW TRANSFORMER to classify anonymity network traffic. FLOW TRANSFORMER uses multi-head attention mechanism to set higher weights for important flows, and extracts flow sequence features according to the importance weights. Besides, the RF-based feature selection method is designed to select the optimal feature combination, which can effectively avoid the insignificant features from reducing the performance and efficiency of the classifier. Experimental results on two real-world traffic datasets demonstrate that the proposed method outperforms state-of-the-art methods with a large margin.