Traffic congestion has become a global concern due to continuous increase in traffic demand and limited road capacity. The ability to predict traffic congestion propagation, which depicts the spatiotemporal evolution of the congestion scenario, is essential for developing smart traffic management systems and enabling road users to make informed route choices. In this work, we study the behavior of congestion propagation at the road segment level, and leverage this to develop a novel machine learning framework that characterizes and predicts the congestion evolution among different road segments in the traffic network. In particular, our framework can infer the likelihood of congestion propagation between any pair of road segments through single or multiple propagation paths. The proposed framework relies on a network embedding module to learn a representation for each road segment, and a propagation model which calculates the congestion propagation likelihood based on the learned representations. Specifically, an asymmetric embedding of local proximity and global tendency (AE-LPGT) is relied upon for learning low dimension embeddings of the road segments which incorporate various realistic properties of congestion propagations, such as the local proximity property, global propagation tendency, and asymmetric transitivity of congestion propagations. Experimental results with Singapore traffic data show that our method significantly outperforms the state-of-the-art, and the congestion propagation properties in our embeddings have significant impact on the prediction performance.

Multimodal public transport networks (MMPTNs) in modern cities are becoming increasingly complex. This makes finding optimal journey routes challenging due to a large number of transfer options that need to be properly considered. Furthermore, the complexity of the problem is compounded when multiple conflicting travel criteria are considered (e.g., travel time, walking distance, travel fare, etc.). This paper proposes a transfer graph (TG) model to explore the transfer opportunities of the MMPTN to support efficient journey route planning. TG considers all possible transfer opportunities, while employing a representative mechanism to optimize the TG structure that supports efficient route planning algorithms. Based on the proposed TG, we develop two exact algorithms to search the Pareto-optimal solutions for multi-criteria journey planning (MCJP) over the MMPTN. The first algorithm runs faster by eliminating many partial solutions at an early stage, which is more suited for lowering computation time at the expense of marginal degradation in output quality. In contrast, the second algorithm provides a more dependable solution by incorporating accurate journey time prediction that caters to the evolving traffic conditions. We also develop techniques to accelerate the TEDE and TEAE algorithms. Experiments on real-world public transport networks and traffic data demonstrate the effectiveness of our approach for MCJP. Experiment results also reveal interesting insights on the impact of the TOs, number of transfers, and number of travel criteria on MCJP algorithms, which can contribute to better public transportation planning.

Metaverse applications often require many new 3D point cloud models that are unlabeled and that have never been seen before; this limited information results in difficulties for data-driven model analyses. In this paper, we propose a novel data-driven 3D point cloud analysis network GN-CNN that is suitable for such scenarios. We tackle the difficulties with a few-shot learning (FSL) approach by proposing an unsupervised generative adversarial network GN-GAN to generate prior knowledge and perform warm start pre-training for GN-CNN. Furthermore, the 3D models in the Metaverse are mostly acquired with a focus on the models’ visual appearances instead of the exact positions. Thus, conceptually, we also propose to augment the information by unleashing and incorporating local variance information, which conveys the appearance of the model. This is realized by introducing a graph convolution-enhanced combined multilayer perceptron operation (CMLP), namely GCMLP, to capture the local geometric relationship as well as a local normal-aware GeoConv, namely GNConv. The GN-GAN adopts an encoder–decoder structure and the GCMLP is used as the core operation of the encoder. It can perform the reconstruction task. The GNConv is used as the convolution-like operation in GN-CNN. The classification performance of GN-CNN is evaluated on ModelNet10 with an overall accuracy of 95.9%. Its few-shot learning performance is evaluated on ModelNet40, when the training set size is reduced to 30%, the overall classification accuracy can reach 91.8%, which is 2.5% higher than Geo-CNN. Experiments show that the proposed method could improve the accuracy in 3D point cloud classification tasks and under few-shot learning scenarios, compared with existing methods such as PointNet, PointNet++, DGCNN, and Geo-CNN, making it a beneficial method for Metaverse applications.

The adoption of large-scale MPSoCs and the globalization of the IC design flow give rise to two major concerns: high power density due to continuous technology scaling and security due to the untrustworthiness of the third-party intellectual property (3PIP) cores. However, little work has been undertaken to consider these two critical issues jointly during the design stage. In this paper, we propose a design methodology that minimizes the energy consumption while simultaneously protecting the MPSoC against the effects of hardware trojans. The proposed methodology consists of three main stages: 1) Task scheduling to introduce core diversity in the MPSoC in order to detect the presence of malicious modifications in the cores, or mute their effects at runtime, 2) Vendor assignment to the cores using a novel heuristic that chooses vendor-specific cores with operating speed that minimizes the total energy consumption of the MPSoC, and 3) Explore optimization opportunities for further energy savings by minimizing idle periods on the cores, which are caused by the inter-task data dependencies. Experimental results show that our solutions consume only 1/3 energy of existing solutions without increasing schedule length while satisfying the security constraints.