Tiancai Liang

Yingjie Wu, Kongyang Chen, Tiancai Liang

Road potholes threaten driving safety and increase infrastructure maintenance costs, while large-scale and timely pothole detection remains challenging in urban road networks. Vehicle-mounted vibration sensing offers a low-cost and scalable solution, however, continuous transmission of raw acceleration streams causes high communication overhead. Also, vibration patterns induced by potholes are often confused with those caused by manholes, speed bumps, and other local road structures. To address these challenges, this paper proposes an edge-cloud collaborative pothole detection framework based on onboard vibration event screening and federated temporal segmentation. At the vehicle side, a Gaussian Mixture Model (GMM)-based module adaptively models background vibration and screens candidate abnormal events from continuous acceleration streams. The onboard module acts as a lightweight high-recall filter and uploads only compact candidate event segments with their contextual information. At the server side, pothole detection is formulated as a point-wise temporal segmentation task. A 1D Attention U-Net is developed to distinguish potholes from vibration-similar road events by capturing multi-scale temporal features and preserving event boundary information. Furthermore, the model is trained under a federated learning framework to exploit distributed multi-vehicle data while accommodating non-IID vehicle data distributions. Experiments on multi-vehicle vibration sensing data show that the proposed framework reduces unnecessary data transmission from smooth road segments and improves fine-grained pothole detection under both centralized and federated settings.

Fengbin Zhang, Haoyi Fan, Ruidong Wang et al.

Networks are ubiquitous in the real world such as social networks and communication networks, and anomaly detection on networks aims at finding nodes whose structural or attributed patterns deviate significantly from the majority of reference nodes. However, most of the traditional anomaly detection methods neglect the relation structure information among data points and therefore cannot effectively generalize to the graph structure data. In this paper, we propose an end-to-end model of Deep Dual Support Vector Data description based Autoencoder (Dual-SVDAE) for anomaly detection on attributed networks, which considers both the structure and attribute for attributed networks. Specifically, Dual-SVDAE consists of a structure autoencoder and an attribute autoencoder to learn the latent representation of the node in the structure space and attribute space respectively. Then, a dual-hypersphere learning mechanism is imposed on them to learn two hyperspheres of normal nodes from the structure and attribute perspectives respectively. Moreover, to achieve joint learning between the structure and attribute of the network, we fuse the structure embedding and attribute embedding as the final input of the feature decoder to generate the node attribute. Finally, abnormal nodes can be detected by measuring the distance of nodes to the learned center of each hypersphere in the latent structure space and attribute space respectively. Extensive experiments on the real-world attributed networks show that Dual-SVDAE consistently outperforms the state-of-the-arts, which demonstrates the effectiveness of the proposed method.

Saghir Ahmed Saghir Alfasly, Yongjian Hu, Tiancai Liang et al.

Vehicle Re-identification is attracting more and more attention in recent years. One of the most challenging problems is to learn an efficient representation for a vehicle from its multi-viewpoint images. Existing methods tend to derive features of dimensions ranging from thousands to tens of thousands. In this work we proposed a deep learning based framework that can lead to an efficient representation of vehicles. While the dimension of the learned features can be as low as 256, experiments on different datasets show that the Top-1 and Top-5 retrieval accuracies exceed multiple state-of-the-art methods. The key to our framework is two-fold. Firstly, variational feature learning is employed to generate variational features which are more discriminating. Secondly, long short-term memory (LSTM) is used to learn the relationship among different viewpoints of a vehicle. The LSTM also plays as an encoder to downsize the features.