Weakly supervised anomalous behavior detection is a popular area at present. Compared to semi-supervised anomalous behavior detection, weakly-supervised learning both eliminates the need to crop videos and solves the problem of semi-supervised learning’s difficulty in handling long videos. Previous work has used graph convolution or self-attention mechanisms to model temporal relationships. However, these methods tend to model temporal relationships at a single scale and lack consideration of the aggregation problem for different temporal relationships. In this paper, we propose a weakly supervised anomaly detection framework, MTDA-Net, with emphasis on modeling different temporal relationships and enhanced semantic discrimination. To this end, we construct a new plug-and-play module, MTDA, which uses three branches, Multi-headed Attention (MHA), Temporal Shift (TS), and Dilated Aggregation (DA), to extract different temporal sequences. Specifically, the MHA branch can globally model the video information and project the features into different semantic spaces to enhance the expressiveness and discrimination of the features. The DA branch extracts temporal information of different scales via dilated convolution and captures the temporal features of local regions in the video. The TS branch can fuse the features of adjacent frames on a local scale and enhance the information flow. MTDA-Net can learn the temporal relationships between video segments on different branches and learn powerful video representations based on these relationships. The experimental results on the XD-Violence dataset show that MTDA-Net can significantly improve the detection accuracy of abnormal behaviors.

To address the challenges of detecting a large number of objects and a high proportion of small objects in aerial drone imagery, we proposed an aerial dense small object detection algorithm called Global Normalization Attention Mechanism You Only Look Once (GNYL) based on the Global Normalization Attention Mechanism. In the backbone network of GNYL, we embedded a GNAM (Global Normalization Attention Mechanism) that explores channel attention features and spatial attention features from input features in a concatenated manner. It utilizes batch normalization’s scale factors to suppress irrelevant channels or pixels. Furthermore, the spatial attention sub-module introduces a three-dimensional arrangement with a multi-layer perceptron to reduce information loss and amplify global interaction representation. Finally, the computed attention weights are weighted to form the global normalized attention weights, which increases the utilization of effective information in input feature channels and spatial dimensions. We have optimized the backbone network, feature enhancement network, and detection heads to improve detection accuracy while ensuring a lightweight detection network. Specifically, we have added a small object detection layer to enhance the localization accuracy for the abundant small objects in aerial imagery. The algorithm’s performance was evaluated using the publicly available VisDrone2019 dataset. Compared to the baseline network YOLOv8l, GNYL achieved a 7.2% improvement in mAP_0.5 and a 5.0% improvement in mAP_0.95. Compared to CDNet, GNYL showed a 14.5% improvement in mAP_0.5 and a 9.1% improvement in mAP_0.95. These experimental results demonstrate the strong practicality of the GNYL object detection network for detecting dense small objects in the aerial imagery captured by unmanned aerial vehicles.

Nasopharyngeal carcinoma (NPC) is a malignant tumor, and early diagnosis and timely treatment are important for NPC patients. Accurate and reliable detection of NPC lesions in magnetic resonance (MR) images is very helpful for the disease diagnosis. However, recent deep learning methods need to be improved for NPC detection in MR images. Because NPC tumors are invasive and usually small in size, it is difficult to distinguish NPC tumors from the closely connected surrounding tissues in a huge and complex background. In this paper, we propose an automatic detection method, named MWSR-YLCA, to accurately detect NPC lesions in MR images. Specifically, we design two modules, the multi-window settings resampling (MWSR) module and an improved YOLOv7 embedded with a coordinate attention mechanism (YLCA) module, to detect NPC lesions more accurately. First, the MWSR generates a pseudo-color version of MR images based on a multi-window resampling method, which preserves richer information. Subsequently, the YLCA detects the NPC lesion areas more accurately by constructing a novel network based on an improved YOLOv7 framework embedded with the coordinate attention mechanism. The proposed method was validated on an MR image set of 800 NPC patients and obtained 80.1% mAP detection performance with only 4694 data samples. The experimental results show that the proposed MWSR-YLCA method can perform high-accuracy detection of NPC lesions and has superior performance.

Sarcasm often arises from subtle contrasts between literal meaning and speaker intention. As online communication increasingly includes voice-based content, detecting sarcasm across speech and text becomes more important—and more complex. The existing methods usually focus on generic multimodal fusion but often miss how sarcasm manifests differently in each modality. We propose a model that explicitly encodes audio signals into the textual representation space, allowing prosodic cues to inform language understanding. To extract relevant features at different levels, we use a multi-scale convolutional architecture. The experiments show consistent gains over prior models on both text and speech sarcasm detection tasks.

Location information on Twitter plays a critical role in emergency detection, event recommendation, and disaster warning. However, only a limited amount of Twitter data are geotagged. Previous research has presented various models for inferring location based on text, social relations, and contextual data, yielding highly promising results. Nonetheless, these existing methods have certain limitations that need to be addressed. Firstly, most of the existing methods overlook the role of local celebrities (well-known users in the local community) as indicators of location within the social network. Secondly, they fail to consider the associations between words in tweets, resulting in insufficiently rich features extracted from the tweets. We propose a multi-view-based location inference model called MVGeo to overcome these limitations. In the network view, our approach employs the Gaussian Mixture Model (GMM) to identify and retain local celebrities, thereby strengthening user location associations. In the tweet view, we construct a heterogeneous graph based on the co-occurrence relationship between words in tweets and the user’s mentioned relationship with the words. This allows us to fully leverage the local correlation between words and the global correlation to extract tweet features more comprehensively. Finally, we employ a modified multi-layer graph convolutional network, called Gate-GCN, to fuse the network and tweet information. This expansion of the feature space enables us to extract sample features from multiple perspectives. To demonstrate the effectiveness of MVGeo, we conduct exhaustive experimental evaluations on a publicly available dataset and compare its performance against several state-of-the-art benchmark models. The results confirm the superior performance of the proposed model.