Recommender Systems in real scenarios suffer from poor representation ability of user–item interaction graph caused by data sparsity and data noise. Most of the existing models have problems of instability and limited generation ability. This article proposes a novel recommendation method called graph generative diffusion with hard negative sampling contrastive learning recommendation method (GGDHSCL) to overcome the limitations above. First, the latent diffusion model (L-diffusion) and parametric topological noise reduction network (PTDNet) were introduced as view generators to improve the limited representation ability and mitigate noise. Second, dual-view contrastive learning was constructed to alleviate the limitations of high-quality data in the recommendation system and the problem of model collapse in the training process. Third, a hard negative sampling strategy was proposed to improve the self-supervised signal. We extensively compared our method with 14 popular baselines on four public datasets (Yelp, BeerAdvocate, Gowalla, and LastFM). Experiments show an improvement of recommendation quality (e.g., that on the BeerAdocate dataset, NDCG@40 is improved by 3.6% and Recall@40 is improved by 3.3% on BeerAdvocate dataset).

The importance of social network alignment (SNA) for various downstream applications, such as social network information fusion and e-commerce recommendation, has prompted numerous professionals to develop and share SNA tools. However, malicious actors can exploit these tools to integrate sensitive user information, thereby posing cybersecurity risks. Although many researchers have explored attacking SNA (ASNA) through network modification attacks to protect users, practical feasibility remains challenging. In this study, we propose an effective node injection attack via a dynamic programming framework (DPNIA) to address the problem of modeling and solving ASNA within a limited time and balancing the costs and benefits. DPNIA models ASNA as a problem of maximizing the number of confirmed incorrect correspondent node pairs with greater similarity scores than the pairs between existing nodes, thereby making ASNA solvable. A cross-network evaluation method is employed directly to identify node vulnerabilities, facilitating progressive attacking from easy to difficult. In addition, an optimal injection strategy searching method based on dynamic programming is used to determine which links should be added between the injected and existing nodes, thereby enhancing the effectiveness of the attack at a low cost. Experiments on four real-world datasets demonstrated that DPNIA consistently and significantly surpasses various baselines when attacking both multiple networks simultaneously and a single network.

Drug-drug interaction (DDI) refers to the inhibitory or enhancing effects between different drugs. Existing DDI prediction methods primarily use graph neural networks (GNNs) to directly represent drug molecular features. However, they often ignore the 3D structures of different atoms within drug molecules and the impact of noise in GNNs on DDI prediction. Consequently, the accuracy of GNN-based DDI prediction remains unsatisfactory. To address these limitations, this study proposes a DDI prediction method based on atomic 3D position encoding and an elastic message passing graph neural network (A3DPE-EMPGNN). Firstly, we construct an atomic feature network based on an attention mechanism and a message passing neural network. This network leverages 3D position encoding based on the molecular centroid to learn the features of different atoms and their associated chemical bonds, thereby constructing a graph-based molecular representation. Secondly, we design a molecular feature network that incorporates an attention mechanism, utilizing multi-head attention to capture interaction information between different drug molecules. Thirdly, we employ an adversarial attack detection and defense strategy, integrating supervised and contrastive loss learning to optimize the model and enhance its robustness while performing DDI prediction. Lastly, we evaluate the effectiveness of A3DPE-EMPGNN on two real-world datasets. Experimental results clearly demonstrate that our method achieves over 98% accuracy across ACC, AUC, AP, and F1-score, outperforming state-of-the-art GNN-based models.

In the real world, the stable operation of a network is usually inseparable from the mutual support of other networks. In such an interdependent network, a node in one layer may depend on multiple nodes in another layer, forming a complex one-to-many dependence relationship. Meanwhile, there may also be higher-order interactions between multiple nodes within a layer, which increase the connectivity within the layer. Interlayer dependencies and intralayer connectivity may become key factors affecting network reliability, because failures within a layer will propagate to another layer through dependencies, and the cascading effects within and between layers may trigger catastrophic network collapse. However, existing research on one-to-many interdependence often neglects intralayer higher-order structures and lacks a unified theoretical framework for interlayer dependencies. Moreover, current research on interdependent higher-order networks typically assumes idealized one-to-one interlayer dependencies, which does not reflect the complexity of real-world systems. These limitations hinder a comprehensive understanding of how such networks withstand failures. Therefore, this article investigates the robustness of one-to-many interdependent higher-order networks under random attacks. Depending on whether node survival requires at least one dependence edge or multiple dependence edges, we propose four interlayer interdependence conditions and analyze the network’s robustness after cascading failures induced by random attacks. Using percolation theory, we establish a unified theoretical framework that reveals how higher-order interaction structures within intralayers and interlayer coupling parameters affect network reliability and system resilience. In addition, we extend our study to partially interdependent hypergraphs. We validate our theoretical analysis on both synthetic and real-data-based interdependent hypergraphs, offering insights into the optimization of network design for enhanced reliability.

Voluntary vaccination is essential to protect oneself from infection and suppress the spread of infectious diseases. Voluntary vaccination behavior is influenced by factors, such as age and interaction patterns. Differences in health consciousness and risk perception based on age result in heterogeneity in vaccination behavior among different age groups. Higher-order interactions among individuals of various ages facilitate the dissemination of vaccine-related information, further influencing vaccination intentions. To investigate the impact of individual age and interaction patterns on vaccination behavior, we propose an epidemic-game coevolution model in which age structure and higher-order interactions are considered. Based on the theoretical framework of epidemic-game coevolution, this work calculates the evolutionarily stable strategies and dynamic equilibrium under imitation dynamics in the well-mixed population. Extensive numerical experiments show that infants and the elderly exhibit conservative attitudes toward vaccination, and the vaccination levels of these two groups have no significant impact on the vaccination behavior of other age groups. The vaccination behavior of children is highly active, while the vaccination behavior of adults depends on the relative cost of vaccination. The increase in vaccination levels among children and adults leads to a decrease in vaccination levels in other groups. Furthermore, the infants exhibit the lowest level of vaccination, while the children have the highest vaccination rate. Higher-order interactions significantly enhance vaccination levels among children and adults.

Online users are typically active on multiple social media networks (SMNs), which constitute a multiplex social network. With improvements in cybersecurity awareness, users increasingly choose different usernames and provide different profiles on different SMNs. Thus, it is becoming increasingly challenging to determine whether given accounts on different SMNs belong to the same user; this can be expressed as an interlayer link prediction problem in a multiplex network. To address the challenge of predicting interlayer links, feature or structure information is leveraged. Existing methods that use network embedding techniques to address this problem focus on learning a mapping function to unify all nodes into a common latent representation space for prediction; positional relationships between unmatched nodes and their common matched neighbors (CMNs) are not utilized. Furthermore, the layers are often modeled as unweighted graphs, ignoring the strengths of the relationships between nodes. To address these limitations, we propose a framework based on multiple types of consistency between embedding vectors (MulCEVs). In MulCEV, the traditional embedding-based method is applied to obtain the degree of consistency between the vectors representing the unmatched nodes, and a proposed distance consistency index based on the positions of nodes in each latent space provides additional clues for prediction. By associating these two types of consistency, the effective information in the latent spaces is fully utilized. In addition, MulCEV models the layers as weighted graphs to obtain representation. In this way, the higher the strength of the relationship between nodes, the more similar their embedding vectors in the latent representation space will be. The results of our experiments on several real-world and synthetic datasets demonstrate that the proposed MulCEV framework markedly outperforms current embedding-based methods, especially when the number of training iterations is small.

With the rapid development of Internet of things technology, the application of intelligent devices in the medical industry has become ubiquitous. Connected devices have revolutionized clinicians and patient care but also made modern hospitals vulnerable to cyber attacks. Among the security risks, botnets are of particular concern, which can be used to control thousands of devices for remote data theft and equipment destruction. In this paper, we propose a non-Markovian spread dynamics model to understand the effects of botnet propagation, which can characterize the hybrid contagion situation in reality. Based on the Susceptible-Adopted-Recovered model, we introduce nonredundant memory spread mechanism for global propagation, as a tuner to adjust spreading rate difference. For describing the proposed model, we extend a heterogeneous edge-based compartmental theory. Through extensive numerical simulations, we reveal that the growth pattern of the final adoption size versus the information transmission probability is discontinuous and how the final adoption size is affected by hybrid ratio α, global scope control factor ϵ, accumulated received information threshold T, and other parameters on ER network. Furthermore, we give the theory and simulation result on BA network and also compare the two hybrid methods—single infection in one time slice and double infections in one time slice—to evaluate the influence on final adoption size. We found in SIOT hybrid contagion scenario the final adoption size shows the phenomenon of a decline followed by an increase versus different hybrid ratio, and it is both verified in theory and numerical simulation. Through validation by thousands of experiments, our developed theory agrees well with the numerical simulations.