Estimation-based optimizations for the semantic compression of RDF knowledge bases

Structured knowledge bases are critical for the interpretability of AI techniques. RDF KBs, which are the dominant representation of structured knowledge, are expanding extremely fast to increase their knowledge coverage, enhancing the capability of knowledge reasoning while bringing heavy burdens to downstream applications. Recent studies employ semantic compression to detect and remove knowledge redundancies via semantic models and use the induced model for further applications, such as knowledge completion and error detection. However, semantic models that are sufficiently expressive for semantic compression cannot be efficiently induced, especially for large-scale KBs, due to the hardness of logic induction. In this article, we present estimation-based optimizations for the semantic compression of RDF KBs from the perspectives of input and intermediate data involved in the induction of first-order logic rules. The negative sampling technique selects a representative subset of all negative tuples with respect to the closed-world assumption, reducing the cost of evaluating the quality of a logic rule used for knowledge inference. The number of logic inference operations used during a compression procedure is reduced by a statistical estimation technique that prunes logic rules of low quality. The evaluation results show that the two techniques are feasible for the purpose of semantic compression and accelerate the compression algorithm by up to 47x compared to the state-of-the-art system.