Contemporary techniques for identifying key nodes in complex networks typically rely on the static topology of the network, often neglecting the potential dynamic information available. We introduce a novel centrality measurement approach named gravity box-coverage and effective distance (GBED). It capitalizes on the notion that the internal structure of the gravity box encapsulates crucial information about nodes. It transforms static Euclidean distance into dynamic effective distance (ED), extracting concealed insights through an analysis of both static and dynamic topological paths. Initially, the ED between nodes is computed based on node arrival probabilities. Subsequently, the box-coverage algorithm defines the influence area of nodes. The improved gravity model is then applied to estimate the interaction ability between nodes. Finally, the local influence capability score of the node’s box, covering the influence region, is calculated. The global influence capability score of the node is aggregated according to the neighborhood rule. We compare it with five established methods based on nine real-world networks. In the SIR epidemic spreading, the nodes identified by GBED exhibit a broader range of influence, and the correlation between estimated influences of nodes from GBED and real influences by simulation is higher than correlations associated with other algorithms.

Graph contrastive learning has demonstrated outstanding performance in addressing the issue of label scarcity. It still has two limitations: 1) the stacking of graph layers often leads to over-smoothing, hard to distinguish the embeddings of distinct nodes; and 2) traditional algorithms typically model user preferences with a unified intention, neglecting the multifaceted and fine-grained motivations behind user-item interactions. To overcome these shortcomings, we propose an adaptive disentangled contrastive learning (AdaDCL) method tailored for recommendation systems. First, we perform disentangled modeling of global information intentions and introduce a cross-view contrastive learning task, employing a parameterized mask generator for adaptive augmentation. Second, we employ a layer attention mechanism to counter over-smoothing in GNNs, ensuring that meaningful semantic features are preserved across layers. Third, an adaptive hardness negative sampling (AHNS) strategy dynamically selects negative samples based on their hardness levels, reducing the risk of false positives and negatives while enhancing the robustness of contrastive learning. Comprehensive experiments on three benchmark datasets, including Gowalla, and comparisons against twelve state-of-the-art baseline models (e.g., DisenHAN), demonstrate that AdaDCL surpasses the classic LightGCN by 5.89% in Recall@20 and over 7% in NDCG@20 on the Gowalla dataset. These results highlight the effectiveness and generalizability of our approach.

Large-scale networks cannot be effectively addressed by global structure-based techniques due to their high temporal complexity, while local structure-based methods may overlook global information. To overcome these limitations, we propose a novel key node identification method for complex networks, named cycle structure, voting mechanism, ranking principle (CVR). This method adopts a multilevel processing approach and an enhanced voting mechanism. Initially, it incorporates the centrality of the network cycle structure and describes the topological locations of nodes within their neighborhoods. Subsequently, the traditional voting mechanism is refined by incorporating both global and local information from complex networks, providing a more accurate representation of relationships between nodes and the structures of neighborhoods in the network. The extended neighborhood ideology is then integrated with the improved voting mechanism, resulting in an effective method for identifying hidden key nodes. The effectiveness of the CVR method is validated through experiments on nine datasets using nine baseline methods, including the susceptible, infective, recovered (SIR) and linear threshold (LT) models, as well as experiments involving the seed selection technique for choosing initial infection nodes. Results show that CVR improves the infection rate by 4.7%–156.8% under varying infection probabilities in the SIR model.

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).

Abstract The problem of detecting communities in real-world networks has been extensively studied in the past, but most of the existing approaches work on single-domain networks, i.e. they consider only one type of relationship between nodes. Single-domain networks may contain noisy edges and they may lack some important information. Thus, some authors have proposed to consider the multiple relationships that connect the nodes of a network, thus obtaining multi-domain networks. However, most community detection approaches are limited to multi-layer networks, i.e. networks generated from the superposition of several single-domain networks (called layers) that are regarded as independent of each other. In addition to being computationally expensive, multi-layer approaches might yield inaccurate results because they ignore potential dependencies between layers. This paper proposes a multi-domain discrete-time quantum walks (MDQW) model for multi-domain networks. First, the walking space of network nodes in multi-domain network is constructed. Second, the quantum permutation circuit of the coin state is designed based on the coded particle state. Then, using different coin states, the shift operator performs several quantum walks on the particles. Finally, the corresponding update rule is selected to move the node according to the measurement result of the quantum state. With continuous update iteration, the shift operator automatically optimizes the discovered community structure. We experimentally compared our MDQW method with four state-of-the-art competitors on five real datasets. We used the normalized mutual information (NMI) to compare clustering quality, and we report an increase in NMI of up to 3.51 of our MDQW method in comparison with the second-best performing competitor. The MDQW method is much faster than its competitors, allowing us to conclude that MDQW is a useful tool in the analysis of large real-life multi-domain networks. Finally, we illustrate the usefulness of our approach on two real-world case studies.

Abstract Most existing cross-domain recommendation (CDR) systems apply the embedding and mapping idea to tackle the cold-start user problem and, to this end, they learn a common bridge function to transfer the user preferences from the source domain into the target domain. However, sharing a bridge function for all users inevitably leads to biased recommendations. This paper proposes a novel method, named CDR to cold-start users via categorized preference transfer (CDRCPT), to overcome the shortcomings of existing approaches. First, the embeddings of users and items in both the source and target domain are learned through pretraining and we utilize preference encoder to obtain the preference embeddings of users in the source domain. Second, mini-batch clustering is applied in the source domain to group users according to their preferences; here, each cluster identifies a specific class of users, and each cluster is represented by its center. Finally, the general representation is fed into a meta network to learn a bridge function for each available class of users. Experiments on two real data sets show that our CDRCPT method is effective in improving the accuracy and robustness of recommendations.

Abstract Previous key node identification approaches assume that the transmission of information on a path always ends positively, which is not necessarily true. In this paper, we propose a new centrality index called Information Rank (IR for short) that associates each path with a score specifying the probability that such path successfully conveys a message. The IR method generates all the shortest paths of any arbitrary length coming out from a node $u$ and defines the centrality of u as the sum of the scores of all the shortest paths exiting $u$. The IR algorithm is more robust than other centrality indexes based on shortest paths because it uses alternative paths in its computation, and it is computationally efficient because it relies on a Beadth First Search-BFS to generate all shortest paths. We validated the IR algorithm on nine real networks and compared its ability to identify super-spreaders (i.e. nodes capable of spreading an infection in a real network better than others) with five popular centrality indices such as Degree, Betweenness, K-Shell, DynamicRank and PageRank. Experimental results highlight the clear superiority of IR over all considered competitors.

Traditional community detection models either ignore the feature space information and require a large amount of domain knowledge to define the meta-paths manually, or fail to distinguish the importance of different meta-paths. To overcome these limitations, we propose a novel heterogeneous graph community detection method (called KGNN_HCD, heterogeneous graph Community Detection method based on K-nearest neighbor Graph Neural Network). Firstly, the similarity matrix is generated to construct the topological structure of K-nearest neighbor graph; secondly, the meta-path information matrix is generated using a meta-path transformation layer (Mp-Trans Layer) by adding weighted convolution; finally, a graph convolutional network (GCN) is used to learn high-quality node representation, and the k-means algorithm is adopted on node embeddings to detect the community structure. We perform extensive experiments and on three heterogeneous datasets, ACM, DBLP and IMDB, and we consider as competitors 11 community detection methods such as CP-GNN and GTN. The experimental results show that the proposed KGNN_HCD method improves 2.54% and 2.56% on the ACM dataset, 2.59% and 1.47% on the DBLP dataset, and 1.22% and 1.67% on the IMDB dataset for both NMI and ARI. Experiments findings suggest that the proposed KGNN_HCD method is reasonable and effective, and KGNN_HCD can be applied to complex network classification and clustering tasks.

With the development of deep learning and other technologies, the research of information propagation prediction has also achieved important research achievements. However, the existing information diffusion studies either focus on the attention relationships of users or they predict the information according to the diffusion relationships of users, which makes the prediction results have certain limitations. Therefore, a prediction model has been proposed spatial–temporal attention heterogeneous graph convolutional networks (STAHGCNs). First, we use GCN to learn user influence relationships and user behavior relationships, and we propose a user representation fusion mechanism to learn the user characteristics. Second, to account for the dynamics of user behavior, a temporal attention mechanism strategy is used to encode time into the heterogeneous graph to obtain a more expressive user representation. Finally, the obtained user representation is input into the multihead attention mechanism for information propagation prediction. Experimental results performed on the Twitter, Douban, Digg, and Memetracker datasets have shown that the proposed STAHGCN model increased by 8.80% and 6.74% at hits@N and map@N, respectively, which are significantly better than the original latest DyHGCN model. The proposed STAHGCN model effectively integrates spatial factors, such as time factor, user influence, and behavior, which greatly improves the accuracy of information propagation prediction and has great significance for rumor monitoring and malicious account detection.

Abstract Target-specific sentiment analysis is an emerging topic in the field of text mining but current approaches to deriving the polarity of a sentence suffer from two main drawbacks: on one hand, we lack of a large and well-curated corpus, and on the other hand, current solutions based on deep learning are particularly vulnerable to the attack of adversarial samples. A novel target-specific sentiment classification method is proposed. Firstly, the method of masking target entities is applied to replace synonyms and insert words randomly; secondly, the target-specific sentiment classification model of adversarial learning is constructed with six baseline models; finally, we combine data enhancement and adversarial learning to construct target-specific sentiment classification model. Experimental results show that Macro-F1 values are improved by 0.30–2.91, 0.88–2.42 and 0.13–1.94% compared to the six baseline models by using Laptop14, Restaurant14 and Twitter original datasets, respectively, using Adversarial learning. Using word-masking data enhancement samples and Adversarial learning from Laptop14, Restaurant14 and Twitter shows that Macro-F1 values are improved by 0.9–2.64, 1.59–3.09 and 0.18–1.71% compared to the six baseline (SC), respectively. Our method can effectively improve the quality of samples, it improves the classification performance and the capability of adversarial samples defense.

In view that the K-shell decomposition method can only effectively identify a single most influential node, but cannot accurately identify a group of most influential nodes, this article proposes a hybrid method based on K-shell decomposition to identify the most influential spreaders in complex networks. First, the K-shell decomposition method is used to decompose the network, and the network is regarded as a hierarchical structure from the inner core to the periphery core. Second, the existing centrality methods such as H-index are used as the secondary score of the proposed method to select nodes in each hierarchy of the network. In addition, for the sake of alleviating the overlapping problem, the Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) method is introduced to calculate the comprehensive score of secondary score and overlapping range, and the node with the highest comprehensive score will be selected in each round. The proposed algorithm can be used as a general framework to improve the existing centrality method which can represent nodes with definite values of centrality. Experimental results show that in the susceptible–infected–recovered (SIR) model experiment, compared with the benchmark methods, the infection scale of the proposed K-TOPSIS method in nine real networks is improved by 1.15%, 2.23%, 1.95%, 3.12%, 6.29%, −0.37%, 4.01%, 0.48%, and 0.48%, respectively. The novel method is improved by 0.44, 1.18, 1.16, 11.30, 2.03, 2.53, 2.70, and 2.13 in average shortest path length experiment, respectively, except for Facebook network. It shows that the novel method is reasonable and effective.

Most rumor detection methods extract the features of rumor through two aspects of text semantics and propagation structure to achieve automatic rumor classification, while most of the existing methods do not realize that false and irrelevant interactions in the propagation structure will reduce the accuracy of rumor detection. In addition, most of the existing rumor detection methods failed to effectively extract key clues from the comments of social network users. In response to these phenomena, this article proposes a social network rumor detection method combining a dual attention mechanism and graph convolutional network (GCN) (dual-attention GCN, DA-GCN). First, build an event propagation graph; then, the GCN is used to extract the propagation structure information of each event-related microblog (tweet), and the attention mechanism is combined to suppress the false and irrelevant interactive relationships. Therefore, the anti-interference propagation structure features are extracted from the propagation graph. Second, to fully utilize the clues in users’ comments, this article makes use of the attention mechanism to fuse source microblog (tweet) with the comment–retweet information and extract interactive semantic features from it. Finally, the above two features are fused to generate a new event representation. Experimental results show that the proposed DA-GCN has an accuracy of 94.4%, 90.5%, and 90.2% on the Weibo dataset, the Twitter15 dataset, and the Twitter16 dataset, respectively, and has achieved excellent performance in the early rumor detection task, which proves that the proposed method is reasonable and effective.

The autoencoder network has been proven to be one of the powerful techniques for recommender systems. Currently, the ways of utilizing autoencoder in recommender systems can be divided into two categories: modeling user-item interaction rely solely on autoencoder and integrating autoencoder with other models. Most existing methods based on autoencoder assume that all features of model’s input are equally the same contributing to the final prediction, which can be regarded as attention weight vectors; however, this hypothesis is not reliable, especially when exploring users’ interaction frequency with different items. Moreover, combining autoencoder with traditional methods, the usual strategy is to leverage a linear kernel of the inner product of user and item vectors to predict user preferences, which will lead to insufficient expression power and hurt the performance of recommendation when facing data sparsity and cold start problems. To tackle the above two problems, we propose a novel hybrid deep learning model for top-n recommendation, called attentive stacked sparse autoencoder (A-SAERec), which can capture attention weights vector of a user for items, and then combined with the neural matrix factorization to improve the performance of recommender model. Extensive experiments on four real-world datasets show that our A-SAERec algorithm has significant improvements over state-of-the-art algorithms.

Abstract In view of the fact that the existing public opinion propagation aspects are mostly based on single-layer propagation network, these works rarely consider the double-layer network structure and the negative opinion evolution. This paper proposes a new susceptible-infected-vaccinated-susceptible negative opinion information propagation model with preventive vaccination by constructing double-layer network topology. Firstly, the continuous-time Markov chain is used to simulate the negative public opinion information propagation process and the nonlinear dynamic equation of the model is derived; secondly, the steady state condition of the virus propagation in the model is proposed and mathematically proved; finally, Monte Carlo method is applied in the proposed model. The parameters of simulation model have an effect on negative public opinion information propagation, the derivation results are verified by computer simulation. The simulation results show that the proposed model has a larger threshold of public opinion information propagation and has more effective control of the scale of negative public opinion; it also can reduce the density of negative public opinion information propagation and suppress negative public opinion information compared with the traditional susceptible infected susceptible model. It also can provide the scientific method and research approach based on probability statistics for the study of negative public opinion information propagation in complex networks.

Abstract This paper proposes a new information dissemination and opinion evolution IPNN (Information Propagation Neural Network) model based on artificial neural network. The feedforward network, feedback network and dynamic evolution algorithms are designed and implemented. Firstly, according to the ‘six degrees separation’ theory of information dissemination, a seven-layer neural network underlying framework with input layer, propagation layer and termination layer is constructed; secondly, the information sharing and information interaction evolution process between nodes are described by using the event information forward propagation algorithm, opinion difference reverse propagation algorithm; finally, the external factors of online social network information dissemination is considered, the impact of external behavior patterns is measured by media public opinion guidance and network structure dynamic update operations. Simulation results show that the proposed new mathematical model reveals the relationship between the state of micro-network nodes and the evolution of macro-network public opinion. It accurately depicts the internal information interaction mechanism and diffusion mechanism in online social network. Furthermore, it reveals the process of network public opinion formation and the nature of public opinion explosion in online social network. It provides a new scientific method and research approach for the study of social network public opinion evolution.

A nonlinear dynamic emergency public event information diffusion system and mathematical model for public events are proposed based on the propagation dynamics. First, public emergency information communication is analyzed and designed, the opinion evolution is divided into and the viewpoint of value, influence, interest, conformity, intimacy five factors of information diffusion for public emergencies; second, the dynamic diffusion network is designed; information propagation mathematical public emergencies the final model is constructed; the proposed model and social reality and the true statistics of empirical experiments are simulated and analyzed. The experimental results show that the model and the real emergency public event propagation process are consistent, the development trend can predict public events, and the proposed mathematical model is reasonable and effective.

With the rapid development of wireless sensor network (WSN) technology and its localization method, localization is one of the basic services for data collection in WSN. The localization accuracy often depends on the accuracy of distance estimation. Because of the constraint in size, power, and cost of sensor nodes, the investigation of efficient location algorithms which satisfy the basic accuracy requirement for WSN meets new challenges. This paper proposes a novel intelligent node localization algorithm in WSN based on beacon nodes to improve the precision in location estimation. Firstly, system model of WSN node localization is constructed according to the WSN environment. Then traditional WSN node localization methods such as DV‐HOP, GA, and PSO are studied. Localization algorithm of WSN is proposed by using dynamic mathematics modeling. And the result of simulation, which is compared to the traditional algorithm, indicated that this algorithm is better to improve the accuracy and coverage of WSN. The simulation results show that the performance of the proposed WSN location algorithm is better than the traditional localization algorithms.

Recommender systems are used to make recommendations about products, information, or services for users. Most existing recommender systems implicitly assume one particular type of user behavior. However, other recommender system utilizes different particular type information by combining different techniques to improve the quality of the recommendation. This paper proposed a novel personalized recommendation method that utilizes semi-supervised clustering based Gaussian mixture model, which provides a hybrid recommender method by combining demographic method and user-based collaborative filtering method. The result from various simulations using MovieLens data set shows that the proposed recommender method performs better and helps to improve the quality of recommendation rating.