CylE: Cylinder Embeddings for Multi-hop Reasoning over Knowledge Graphs
Chau Duc Minh Nguyen, Tim French, Wei Liu, Michael G. Stewart · 2023
Recent geometric-based approaches have been shown to efficiently model complex logical queries (including the intersection operation) over Knowledge Graphs based on the natural representation of Venn diagram.Existing geometric-based models (using points, boxes embeddings), however, cannot handle the logical negation operation.Further, those using cones embeddings are limited to representing queries by two-dimensional shapes, which reduced their effectiveness in capturing entities query relations for correct answers.To overcome this challenge, we propose unbounded cylinder embeddings (namely CylE), which is a novel geometric-based model based on threedimensional shapes.Our approach can handle a complete set of basic first-order logic operations (conjunctions, disjunctions and negations).CylE considers queries as Cartesian products of unbounded sector-cylinders and consider a set of nearest boxes corresponds to the set of answer entities.Precisely, the conjunctions can be represented via the intersections of unbounded sector-cylinders.Transforming queries to Disjunctive Normal Form can handle queries with disjunctions.The negations can be represented by considering the closure of complement for an arbitrary unbounded sector-cylinder.Empirical results show that the performance of multihop reasoning task using CylE significantly increases over state-of-the-art geometric-based query embedding models for queries without negation.For queries with negation operations, though the performance is on a par with the best performing geometric-based model, CylE significantly outperforms a recent distributionbased model.