Despite the success of Graph Neural Networks (GNNs) in modeling recommender systems as bipartite graphs, their ability to capture diverse user-item relations remains limited by the sparsity of observed interactions, which fails to reveal the underlying latent intents. We propose IACLR (Intention Alignment via Contrastive Learning for bipartite graph Recommendation), a framework that constructs an Intent-Graph by augmenting the bipartite recommendation graphs with an implicit intent layer. Instead of relying solely on observed edges, IACLR introduces a set of intent nodes that bridge users and items through shared semantic and behavioral patterns. These nodes are used to construct an Intent-Graph, where they act as both intermediaries that enrich structural connectivity and global anchors that summarize latent user interests. Within this graph, IACLR performs contrastive alignment across multiple data views and enforces consistency among users, intents, and items, thereby enhancing robustness under data sparsity. Experiments on benchmark datasets (e.g., Amazon-books and Yelp) demonstrate that IACLR consistently outperforms strong graph-based, revealing its effectiveness in capturing fine-grained user–item relationships and integrating multi-faceted signals. The framework is applicable to various recommendation scenarios, including academic paper recommendations, e-commerce, and content platforms.

Graph neural networks (GNNs) are widely used in information retrieval, but they often require large amounts of labeled data. To address this problem, self-supervised methods like graph contrastive learning (GCL) are developed to learn from graph structures without labeled data. However, GCL faces a challenge in practice. Plenty of traditional GCL methods differ fundamentally from GNNs in handling neighboring nodes, hindering effective contrastive learning. To address the above issue, we propose a graph self-supervised learning model based on Contrastive Graph Matching (ConGM). The model effectively mitigates the conflict between GCL methods and the homophily assumption of GNNs by using linear node matching and quadratic edge alignment mechanisms to treat some neighboring nodes as both positive and negative samples, rather than considering all neighboring nodes as negative samples as in traditional GCL methods. Additionally, to tackle the imbalance of positive and negative samples in edge alignment, we design a bi-level negative sample selection strategy to choose appropriate hard negative samples. Extensive experiments conducted on multiple benchmark datasets have validated the effectiveness of our proposed method.

Signed bipartite graphs are widely employed in social networks, recommender systems, and other domains, where the nodes represent two different sets, such as users and commodities, and the links have positive and negative signs to reflect the ratings. Link sign prediction is a crucial task, but the link class imbalance when one type of link (e.g., the head class) is significantly more numerous than another (e.g., the tail class) makes this task extremely challenging. To address this challenge, we propose a Line-Graph-Based Dynamic Balancing Prediction (LDBP) method. Specifically, we first convert the links of a signed bipartite graph into nodes of a line graph, and then the link class imbalance problem in the bipartite graph is naturally transformed to the problem of node class imbalance in the line graph. To tackle this problem, we introduce a Centroid Contrastive Learning (CCL) method and design a Dynamic Synthesis & Deletion (DSD) strategy for the tail-class nodes. By dynamically adjusting the quantity of synthesized tail-class nodes, we obtain a Balanced Line Graph (BaLG). Extensive experiments on real-world datasets demonstrate the effectiveness of our method in improving the accuracy of link sign prediction and addressing the issue of link class imbalance.

Personalized news recommendation plays a vital role in mitigating information overload, yet challenges persist in accurately capturing user preferences and fine-grained interests. Leveraging the semantic understanding and extraction capabilities of large language models (LLMs), we propose a Multi-Interest Personalized News Recommendation (MIPNR) model to address these issues. MIPNR separately models user interests at the user, news, and entity levels. Specifically, we introduce a Category-Guided Interest-News Matching (CGIN-Matching) method to identify potential interests, a Local News Entity Graph (LNEG) to model subtle entity relationships, and an entity-wise attention mechanism to extract fine-grained interests. In addition, LLMs are used to generate explicit textual descriptions of user preferences. Extensive experiments on real-world datasets demonstrate the effectiveness of our approach.

Continual graph learning (CGL) aims to mitigate the topological-feature-induced catastrophic forgetting problem (TCF) in graph neural networks, which plays an essential role in the field of information retrieval. The TCF is mainly caused by the forgetting of node features of old tasks and the forgetting of topological features shared by old and new tasks. Existing CGL methods do not pay enough attention to the forgetting of topological features shared between different tasks. In this paper, we propose a transformer-based CGL method (Trans-CGL), thereby taking full advantage of the transformer's properties to mitigate the TCF problem. Specifically, to alleviate forgetting of node features, we introduce a gated attention mechanism for Trans-CGL based on parameter isolation that allows the model to be independent of each other when learning old and new tasks. Furthermore, to address the forgetting of shared parameters that store topological information between different tasks, we propose an asymmetric mask attention regularization module to constrain the shared attention parameters ensuring that the shared topological information is preserved. Comparative experiments show that the method achieves competitive performance on four real-world datasets.

Cold-start is a long-standing and challenging problem in recommendation systems. To tackle this issue, many cross-domain recommendation approaches are proposed. However, most of them follow a two-stage embedding-and-mapping paradigm, which is hard to be optimized. Besides, they ignore the structure information of the user-item interaction graph, resulting in that the embedding is insufficient to capture the latent collaborative filtering effect. In this paper, we propose a Dual Autoencoder Network (DAN), which implements cross-domain recommendations to cold-start users in an end-to-end manner. The graph convolutional network (GCN) based encoder in DAN explicitly captures high-order collaborative information in user-item interaction graphs. The two-branched decoder is proposed for fully exploiting the data across domains, and therefore the elaborate reconstruction constraints are obtained under a domain swapping strategy. Experiments on two pairs of real-world cross-domain datasets demonstrate that DAN outperforms existing state-of-the-art methods.

Chemical Structural Formula(CSF) recognition plays an important role in the molecular design and component retrieval. However, sketch-based CSF recognition remains an obstacle in current retrieval systems. This paper introduces a system for sketch CSF recognition on smart mobile devices. A dual-mode-based method is proposed to distinguish the gestures for character inputs and non-character inputs instead of the ordinary segmentation approaches. An attribute graph model is established to describe effectively all necessary information of a sketched CSF. Chemical knowledge is adopted to refine the candidates of structure relationship among elements. The experiments results demonstrate that the proposed method outperforms the existing methods for free-sketch CSFs on effectiveness and flexibility.