A Revised Translation-Based Method for Knowledge Graph Representation

Knowledge graph is of great research value to artificial intelligence, which has been extensively applied in the fields of semantic search and question answering, etc. Knowledge graph representation transforms a large-scale knowledge graph comprising entities and relations into a continuous vector space. To this end, there have been a number of models and methods proposed for knowledge embedding. Among them, TransE is a classic translation-based method that is of low model complexity, high computational efficiency, as well as good capability of expressing knowledge. However, TransE still has two flaws: one is that it utilizes inflexible Euclidean distance as metric, and treats each feature dimension identically, hence, the model accuracy may be interfered by irrelevant dimensions; the other is that it has limitations in dealing with complex relations including reflexive, one-to-many, many-to-one and many-to-many relations. Currently, there has not been a single method that resolves the flaws simultaneously, and thus, we propose a revised translation-based method for knowledge graph representation, namely, TransAH. For the first flaw, TransAH adopts an adaptive metric, replacing Euclidean distance with weighted Euclidean distance by adding a diagonal weight matrix, which assigns different weights to every feature dimension. As to the second, inspired by TransH, it introduces the relation-oriented hyperspace model, projecting head and tail entities to hyperspace of a given relation for distinction. At last, empirical studies on public real knowledge graph datasets analyze and verify the effectiveness of the proposed method. Comprehensive comparative experiments using two tasks-link prediction and triplet classification show that, in contrast to the existing models and methods, TransAH achieves remarkable improvement in various aspects and demonstrates its superiority.