Information diffusion prediction plays a crucial role in understanding the propagation of information in social networks, encompassing both macroscopic and microscopic prediction tasks. Macroscopic prediction estimates the overall impact of information diffusion, while microscopic prediction focuses on identifying the next user to be influenced. While prior research often concentrates on one of these aspects, a few tackle both concurrently. These two tasks provide complementary insights into the diffusion process at different levels, revealing common traits and unique attributes. The exploration of leveraging common features across these tasks to enhance information prediction remains an underexplored avenue. In this paper, we propose an intuitive and effective model that addresses both macroscopic and microscopic prediction tasks. Our approach considers the interactions and dynamics among cascades at the macro level and incorporates the social homophily of users in social networks at the micro level. Additionally, we introduce adversarial training and orthogonality constraints to ensure the integrity of shared features. Experimental results on four datasets demonstrate that our model significantly outperforms state-of-the-art methods.

Group Recommendation means recommending satisfying activities to a group of users in social networks. Most existing aggregation methods mainly focus on aggregating the user's rating for the item according to the rating feature. They ignore the rationality and interpretability of user weights in aggregate function. Moreover, the user weights determined by these methods cannot be adaptively changed with different groups and items. In this paper, we propose an adaptive (AG) aggregation method based on item genre. The AG method does two things: first, uses item genre information to extract a reasonable user weight; second, performs adaptive weight modeling. In addition, we consider that there will be interactions among members in the group decision-making process, so the weights of members may be adjusted appropriately. In order to consider this reasonable factor in our recommendation system, we improved the AG method from the perspective of group member weight deviation. Extensive experimental results on MovieLens dataset clearly demonstrate the effectiveness of our proposed AG.

Understanding the dynamic properties of epidemic spreading on complex social networks is essential to make effective and efficient public health policies for epidemic prevention and control. In recent years, the concept of network embedding has attracted lots of attention to deal with various network analytic tasks, the purpose of which is to encode relationships or information of networked elements into a low-dimensional vector space. However, most existing embedding methods have focused mainly on preserving static network information, such as structural proximity, node/edge attributes, and labels. On the contrary, in this paper, we focus on the embedding problem of preserving dynamic characteristics of epidemic spreading on social networks. We propose a novel embedding method, namely EpiRep, to learn node representations of a network by maximizing the likelihood of preserving groups of infected nodes due to the epidemics starting from every single node on the network. Specifically, the Susceptible-Infectious model is adopted to simulate the epidemic dynamics on networks, and the Continuous Bag-of-Words model with negative sampling is used to obtain node representations. Experimental results show that the EpiRep method outperforms two benchmark random-walk based embedding methods in terms of node clustering and classification on several synthetic and real-world networks. The proposed method and findings in this paper may offer new insight for source identification and infection prevention in the face of epidemic spreading on social networks.

Diffusion on social networks refers to the process where opinions are spread via the connected nodes. Given a set of observed information cascades, one can infer the underlying diffusion process for social network analysis. The independent cascade model (IC model) is a widely adopted diffusion model where a node is assumed to be activated independently by any one of its neighbors. In reality, how a node will be activated also depends on how its neighbors are connected and activated. For instance, the opinions from the neighbors of the same social group are often similar and thus redundant. In this paper, we extend the IC model by considering that: 1) the information coming from the connected neighbors are similar and 2) the underlying redundancy can be modeled using a dynamic structural diversity measure of the neighbors. Our proposed model assumes each node to be activated independently by different communities (or components) of its parent nodes, each weighted by its effective size. An expectation maximization algorithm is derived to infer the model parameters. We compare the performance of the proposed model with the basic IC model and its variants using both synthetic data sets and a real-world data set containing news stories and Web blogs. Our empirical results show that incorporating the community structure of neighbors and the structural diversity measure into the diffusion model significantly improves the accuracy of the model, at the expense of only a reasonable increase in run-time.

A cellular automaton model based on dynamic floor-field is proposed by incorporating the effect of guiding information during evacuation process. The guiding information which is regarded as an important factor to pedestrian dynamics is depicted by introducing a parameter to adjust the static value and the moving direction of pedestrians to move to the emergency exit which is not familiarized by most of the people. In addition, rules are made to deal with conflicts and the following behavior is introduced during the simulation process. Applying the proposed model, simulation of a room with two exits is presented. The simulation result shows that: (i) Several typical phenomena during pedestrian evacuation have been observed during the simulation process, e.g. arching, alignment and clogging. (ii) In comparison to the static model, guiding information has been proved as a key factor to increase the evacuation efficiency which is approximately 43.75%.

Diffusion is known to be an important process governing the behaviours observed in network environments like social networks, contact networks, etc. For modeling the diffusion process, the Independent Cascade Model (IC Model) is commonly adopted and algorithms have been proposed for recovering the hidden diffusion network based on observed cascades. However, the IC Model assumes the effects of multiple neighbors on a node to be independent and does not consider the structural diversity of nodes' neighbourhood. In this paper, we propose an extension of the IC Model with the community structure of node neighbours incorporated. We derive an expectation maximization (EM) algorithm to infer the model parameters. To evaluate the effectiveness and efficiency of the proposed method, we compared it with the IC model and its variants that do not consider the structural properties. Our empirical results based on the MemeTracker dataset, shows that after incorporating the structural diversity, there is a significant improvement in the modelling accuracy, with reasonable increase in run-time.