Towards a Unifying Approach to Representing and Querying Temporal Data in Description Logics

Abstract

Establishing a generic approach to representing and querying temporal data in the context of Description Logics (DLs) is an important, and still open challenge. The difficulty lies in that a proposed approach should reconcile a number of valuable contributions coming from diverse, yet relevant research lines, such as temporal databases and query answering in DLs, but also temporal DLs and Semantic Web practices involving rich temporal vocabularies. Within such a variety of influences, it is critical to carefully balance theoretical foundations with good prospects for reusing existing techniques, tools and methodologies. In this paper, we attempt to make first steps towards this goal. After providing a comprehensive overview of the background research and identifying the core requirements, we propose a general mechanism of defining temporal query languages for time-stamped data in DLs, based on combinations of linear temporal logics with first-order queries. Further, we advocate a controlled use of epistemic semantics in order to warrant practical query answering. We systematically motivate our proposal and highlight its basic theoretical and practical implications. Finally, we outline open problems and key directions for future research.

Temporal query entailment in the Description Logic SHQ

“…Of the other related work mentioned in the previous subsection, the ones described in [24,25,23,28] are most closely related to our work. Nevertheless, they differ from our approach in several ways:…”

“…• In contrast to [28], we consider also the case of rigid concept and role names. In [25,24], rigid names are also used, but in the context of light-weight DLs.…”

“…A similar approach is pursued in [28] to combine a generic DL query component with a linear temporal dimension. To simplify the decision procedures, both components are decoupled via an autoepistemic modal operator.…”

Reasoning Web. Web Logic Rules

“…ontology language that they generalize [10,15,17,18,21,53,[103][104][105][106][107]109,110,[128][129][130]134,140,146,147,150,154,170,175]; -the allowed fuzzy constructs [14,71,72,[77][78][79][80][81][82][83][84]111,157]; -the underlying fuzzy logic [12,13,19,68,69,145,149,152]; -their reasoning algorithms and computational complexity results [4,5,8,9,11,16,[26][27][28]…”

“…A general framework for answering temporal queries over temporal data in the presence of classical ontologies was proposed in [104], considering queries with temporal operators over time-stamped databases, but with a global TBox (axioms hold at all moments of time) formulated in classical (non-temporal) DLs. A general framework for answering temporal queries over temporal data in the presence of classical ontologies was proposed in [104], considering queries with temporal operators over time-stamped databases, but with a global TBox (axioms hold at all moments of time) formulated in classical (non-temporal) DLs.…”