Clustering is a fundamental task in graph data mining, including both node-level and graph-level clustering. While the former has been extensively explored to capture local structures and features, the latter has gained attention for its ability to capture global relationships and high-level abstractions. However, existing methods often address these two tasks in isolation, which not only wastes computational resources but also fails to fully leverage the knowledge from both levels to improve each other, hindering consistent performance improvement. To this end, we propose a novel Unified Graph Clustering Network called UGCN, which employs both local and global graph information to address node- and graph-level clustering collaboratively. In detail, we design a dual-branch projector that performs joint learning at both node and graph levels. The first branch extracts node-level features and projects them into distinct cluster layers, where the derived prototypes are used to refine graph attributes and highlight clustering-friendly substructures. In parallel, the second branch captures subgraph embeddings and aggregates them into discriminative graph-level representations. we align the two branches through joint contrastive objectives to establish a bidirectional interaction: refined prototypes guide subgraph and graph-level clustering, while graph-level pseudo-labels provide feedback to enhance node-level clustering. Extensive experimental results across seven datasets demonstrate that our method significantly outperforms existing state-of-the-art approaches.

The Internet of Medical Things (IoMT) has emerged as a research hotspot in both academic circles and medical institutions. Within IoMT systems, IoT devices collect and upload patient data via sensors, enabling doctors to provide remote treatment to patients. However, the sensitive data involved in IoMT has raised concerns regarding user authentication and data privacy. To address these issues, signcryption has emerged as a promising solution, offering integrity, confidentiality, and unforgeability. Unfortunately, most existing signcryption schemes are not practical for IoMT due to their high computational and storage requirements. In this paper, we propose a signcryption scheme that can provide efficient identity authentication and data sharing for IoMT. Our designed scheme facilitates the secure transmission of medical data between doctors and patients, effectively verifies user legitimacy, and minimizes the risk of private information leakage. To achieve this, we leverage aggregate signature technology to batch verify the correctness of patients' medical data. We also formally prove the security of our proposed design, including existential unforgeability against chosen message attack (EU-CMA) and indistinguishability against chosen plaintext attack (IND-CPA). Finally, comprehensive performance evaluations show that compared with existing schemes, our verification time remains stable at 0.05 seconds, independent of the number of messages. The evaluation results demonstrate that our solution is practical and efficient.

This paper addresses the critical need for accurate and reliable point cloud quality assessment (PCQA) in various applications, such as autonomous driving, robotics, virtual reality, and 3D reconstruction. To meet this need, we propose a large language model (LLM)-guided PCQA approach based on graph learning. Specifically, we first utilize the LLM to generate quality description texts for each 3D object, and employ two CLIP-like feature encoders to represent the image and text modalities. Next, we design a latent feature enhancer module to improve contrastive learning, enabling more effective alignment performance. Finally, we develop a graph network fusion module that utilizes a ranking-based loss to adjust the relationship of different nodes, which explicitly considers both modality fusion and quality ranking. Experimental results on three benchmark datasets demonstrate the effectiveness and superiority of our approach over 12 representative PCQA methods, which demonstrate the potential of multi-modal learning, the importance of latent feature enhancement, and the significance of graph-based fusion in advancing the field of PCQA.

Mobile crowdsensing (MCS) is an efficient approach for large-scale sensing data collection by leveraging the mobility and capability of mobile devices. To avoid the weaknesses of traditional centralized crowdsensing systems, blockchain has been introduced to secure the process of MCS. This paper studies a location-aware scenario, where privacy of users are protected in a blockchain- based MCS system, and formulates an optimization problem to maximize the coverage given a budget based on reverse auction. An incentive mechanism named MMCB is further proposed and implemented as smart contracts in blockchain to solve the problem. We demonstrate that the mechanism achieves a set of desirable properties, including computation efficiency, individual rationality, truthfulness, budget feasibility, approximation, and privacy preservation. To protect the identity privacy of workers and obtain anonymity, a linkable ring signature is employed in smart contracts. In addition, a Pedersen commitment is utilized for protecting workers’ bid profile and the submitted sensing data is encrypted and only accessible to the requester. We implement a prototype system based on the Hyperledger Fabric platform, and the evaluation results show that our privacy-preserving incentive mechanism architecture improves 36.2% coverage and reduces 53.1% payment with better security level compared to the state-of-the-art schemes.

The imaging genetics approach generates large amount of high dimensional and multi-modal data, providing complementary information for comprehensive study of Schizophrenia, a complex mental disease. However, at the same time, the variety of these data in structures, resolutions, and formats makes their integrative study a forbidding task. In this paper, we propose a novel model called Joint Sparse Collaborative Regression (JSCoReg), which can extract class-specific features from different health conditions/disease classes. We first evaluate the performance of feature selection in terms of Receiver operating characteristic curve and the area under the ROC curve in the simulation experiment. We demonstrate that the JSCoReg model can achieve higher accuracy compared with similar models including Joint Sparse Canonical Correlation Analysis and Sparse Collaborative Regression. We then applied the JSCoReg model to the analysis of schizophrenia dataset collected from the Mind Clinical Imaging Consortium. The JSCoReg enables us to better identify biomarkers associated with schizophrenia, which are verified to be both biologically and statistically significant.

With the development of multi-model neuroimaging technology and gene detection technology, the efforts of integrating multi-model imaging genetics data to explore the virulence factors of schizophrenia (SZ) are still limited. To address this issue, we propose a novel algorithm called group sparse of joint non-negative matrix factorization on orthogonal subspace (GJNMFO). Our algorithm fuses single nucleotide polymorphism (SNP) data, function magnetic resonance imaging (fMRI) data and epigenetic factors (DNA methylation) by projecting three-model data into a common basis matrix and three different coefficient matrices to identify risk genes, epigenetic factors and abnormal brain regions associated with SZ. Specifically, we introduce orthogonal constraints on the basis matrix to discard unimportant features in the row of coefficient matrices. Since imaging genetics data have rich group information, we draw into group sparse on three coefficient matrices to make the extracted features more accurate. Both the simulated and real Mind Clinical Imaging Consortium (MCIC) datasets are performed to validate our approach. Simulation results show that our algorithm works better than other competing methods. Through the experiments of MCIC datasets, GJNMFO reveals a set of risk genes, epigenetic factors and abnormal brain functional regions, which have been verified to be both statistically and biologically significant.

The increasing diversity of Internet-of-Things (IoT) application scenarios and explosive growth of access devices have brought more frequent exchanges of resources between different administrative domains. Cross-domain authentication has become a key to safeguard communication and resource interaction among domains. Traditional centralized authentication schemes present heavy management overhead and trust challenges in cross-domain scenarios. Most of existing studies are incapable of establishing trust relationships between domains deployed with different authentication schemes, rendering such high-cost schemes difficult to be generalized. Further, the cross-domain scenario of IoT also raises additional requirements for device privacy and system overhead. In order to tackle these issues, this paper proposes a complete cross-domain authentication and privacy protection scheme, called CCAP, for the IoT based on consortium blockchain. CCAP achieves cross-domain authentication among the IoT domains which may have different configurations from each other. Further, CCAP can be cost-effectively deployed in resource-limited IoT domains and can offer privacy protection and efficient and secure communication for IoT devices. We demonstrate the effectiveness and efficiency of the scheme through experiments in virtual and physical experiment environments as well as comparing and analyzing CCAP with state-of-the-art work.