Hierarchical-aware relation rotational knowledge graph embedding for link prediction

Knowledge graph embedding, as the upstream task of link prediction which aims to predict new links between entities under the premise of known relations, its reliability greatly affects the performance of link prediction. However, previous distance-based models focus on modeling complicated relation patterns while ignoring the semantic hierarchy of knowledge graph, from TransE to RotatE. In this setting, all entities are regarded as the same type, and the fact that different entities belong to different levels is neglected. Therefore, we propose the general form of RotatE, the hierarchical-aware relation rotational knowledge graph embedding (HA-RotatE), to model the hierarchical-aware knowledge graph. HARotatE represents entities and relations as complex vectors and uses different moduli of entity embed dings to indicate the different hierarchical levels they belong to. The transformation of modulus and rotation from head entity to tail entity depends on different relations. Some relations are used to link entities of the same level, and others are used to link entities of different levels. We adopt the shared modulus transformation parameter method for avoiding overfitting. As the general form of RotatE, HA-RotatE also has the ability to model and infer various relation modes, i.e., symmetry/antisymmetric, inversion and composition. On benchmark datasets WN18RR and FB15k-237, the experiments on link prediction tasks show that: (1) HA-RotatE can effectively model the semantic hierarchy of the knowledge graph; (2) Compared with competitive benchmarks, our model substantially outperforms them in most metrics. (c) 2021 Elsevier B.V. All rights reserved.