Abnormal Event Detection via Heterogeneous Information Network Embedding

Heteregeneous information networks (HINs) are ubiquitous in the real world, and discovering the abnormal events plays an important role in understanding and analyzing the HIN. The abnormal event usually implies that the number of co-occurrences of entities in a HIN are very rare, so most of the existing works are based on detecting the rare patterns of events. However, we find that the number of co-occurrences of majority entities in events are the same, which brings great challenge to distinguish the normal and abnormal events. Therefore, we argue that considering the heterogeneous information structure only is not sufficient for abnormal event detection and introducing additional valuable information is necessary. In this paper, we propose a novel deep heterogeneous network embedding method which incorporates the entity attributes and second-order structures simultaneously to address this problem. Specifically, we utilize type-aware Multilayer Perceptron (MLP) component to learn the attribute embedding, and adopt the autoencoder framework to learn the second-order aware embedding. Then based on the mixed embeddings, we are able to model the pairwise interactions of different entities, such that the events with small entity compatibilities have large abnormal event score. The experimental results on real world network demonstrate the effectiveness of our proposed method.