For intelligent surveillance systems, abnormal event detection automatically analyses surveillance video sequences and detects abnormal objects or unusual human actions at the frame level. Due to the lack of labelled data, most approaches are semi-supervised based on reconstruction or prediction methods. However, these methods may not generalize well to unseen scene contexts. To address this issue, we present a novel self and mutual scene-adaptive matching method for abnormal event detection. In the framework, we propose synergistic pose estimation and object detection, which effectively integrates human pose and object detection information to improve pose estimation accuracy. Then, the poses are resized to reduce the spatial distance between the source and target domains. The improved pose sequences are further fed into a spatio-temporal graph convolutional network to extract the geometric features. Finally, the features are embedded in a clustering layer to classify action types and compute normality scores. The training data is taken from the training part of common video anomaly detection datasets: UCSD PED1 & PED2, CHUK Avenue, and ShanghaiTech Campus. The proposed framework is evaluated on video sequences with unseen scene contexts in the UCSD PED2 and ShanghaiTech Campus datasets. The detection accuracy and efficiency are also evaluated in detail, and the proposed method for abnormal event detection achieves the highest AUC performance, 84.6%, on the ShanghaiTech Campus dataset and relatively high AUC performance, 96.9% and 74.8%, on UCSD PED2 & PED1 datasets. Compared with other state-of-the-art works, the performance analysis and results confirm the robustness and effectiveness of our proposed framework for cross-scene abnormal event detection.

In this article, we propose a position and orientation-aware one-shot learning framework for medical action recognition from signal data. The proposed framework comprises two stages and each stage includes signal-level image generation (SIG), cross-attention (CsA), and dynamic time warping (DTW) modules and the information fusion between the proposed privacy-preserved position and orientation features. The proposed SIG method aims to transform the raw skeleton data into privacy-preserved features for training. The CsA module is developed to guide the network in reducing medical action recognition bias and more focusing on important human body parts for each specific action, aimed at addressing similar medical action related issues. Moreover, the DTW module is employed to minimize temporal mismatching between instances and further improve model performance. Furthermore, the proposed privacy-preserved orientation-level features are utilized to assist the position-level features in both of the two stages for enhancing medical action recognition performance. Extensive experimental results on the widely-used and well-known NTU RGB+D 60, NTU RGB+D 120, and PKU-MMD datasets all demonstrate the effectiveness of the proposed method, which outperforms the other state-of-the-art methods with general dataset partitioning by 2.7%, 6.2% and 4.1%, respectively.

Due to maritime transportation being the most crucial mode in international trade, maritime traffic safety significantly influences global economic development. Detecting anomalous ship behaviors (DASB) serves as a critical measure to safeguard maritime traffic safety. In recent years, data-driven deep learning technologies have witnessed remarkable advancements, and the introduction of high-quality DASB datasets facilitates the rapid and effective transformation of traditional DASB methods into intelligent ones. In this paper, we initially present a labeled DASB dataset named NCL-DASB, recorded at the Tynemouth port in Newcastle, UK. Subsequently, we propose a standard framework for processing vessel AIS data, enabling the transformation of AIS data into vessel trajectory feature information suitable for deep learning through preprocessing. Finally, we open-source an API for annotating vessel trajectory data in the NCL-DASB dataset, intended for the use of future researchers in their studies.

In this paper, we address the classification of medical actions with only one single sample by developing a novel one-shot learning framework which contains both cross-attention and dynamic time warping (DTW) modules. To be concrete, we firstly transform the raw skeleton sequence into the signal-level image representation. We exploit a metric learning approach, which is the prototypical network for the proposed one-shot learning framework and choose the residual network (ResNet18) as the backbone which is widely used in recent years. Cross-attention is applied for guiding the network to focus on the more important joints from each specific action. The cross-attention mechanism that applies between the support and query set will be adapted for mining and matching the relationships with the human body. Furthermore, a DTW module is introduced to mitigate the temporal information mismatching issue between the actions from the support and query sets. The experimental results on the NTU RGB+D 120 dataset demonstrate the effectiveness of our proposed approach and the improved performance compared to the baseline approach. The code of this work is available at1.