Semi-Supervised Node Classification Algorithm Based on Hierarchical Contrastive Learning
LI Yaqi1, WANG Jie2, WANG Feng1, LIANG Jiye1
1. School of Computer and Information Technology, Shanxi University, Taiyuan 030006; 2. College of Computer Science and Technology, Taiyuan University of Science and Technology, Taiyuan 030024
Abstract:Most graph contrastive learning methods for semi-supervised node classification obtain two views by cumbersome data augmentation. Moreover, the above data augmentation inevitably changes the graph semantic information, limiting the efficiency and applicability of the existing graph contrastive learning methods. Therefore, a semi-supervised node classification algorithm based on hierarchical contrastive learning is proposed in this paper. In the proposed algorithm, graph data augmentation is unnecessary and the representations of different hierarchies of the graph neural network are learned as contrasted views to alleviate the tedious search and the semantic destruction. In addition, a semi-supervised contrastive loss is designed, and a small amount of labeled information and a large amount of unlabeled information are effectively utilized to provide rich supervised signals and improve the node representations. Finally, node classification experiments on four benchmark datasets validate the effectiveness of the proposed algorithm.
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