Optimal Alignment of Temporal Knowledge Bases

TL;DR

This paper introduces the TKB Alignment problem, aiming to minimally modify temporal knowledge bases to ensure accurate query answering, using cost-optimal solutions for ALC TKBs and LTL-based queries.

Contribution

It formulates the TKB Alignment problem and develops a solution extending propositional LTL alignment techniques for more complex temporal knowledge bases.

Findings

Proposed a formal definition of the TKB Alignment problem.

Developed a solution technique for cost-optimal TKB alignment.

Extended propositional LTL alignment methods to ALC TKBs.

Abstract

Answering temporal CQs over temporalized Description Logic knowledge bases (TKB) is a main technique to realize ontology-based situation recognition. In case the collected data in such a knowledge base is inaccurate, important query answers can be missed. In this paper we introduce the TKB Alignment problem, which computes a variant of the TKB that minimally changes the TKB, but entails the given temporal CQ and is in that sense (cost-)optimal. We investigate this problem for ALC TKBs and conjunctive queries with LTL operators and devise a solution technique to compute (cost-optimal) alignments of TKBs that extends techniques for the alignment problem for propositional LTL over finite traces.