- Authors
- Walter Forkel Technische Universität Dresden
- title
- Closed-World Semantics for Query Answering in Temporal Description Logics
- Please use the following URL when quoting:
- https://nbn-resolving.org/urn:nbn:de:bsz:14-qucosa2-737736
- Date of submission
- 06.10.2020
- Date of defense
- 18.12.2020
- Abstract (EN)
- Ontology-mediated query answering is a popular paradigm for enriching answers to user queries with background knowledge. For querying the absence of information, however, there exist only few ontology-based approaches. Moreover, these proposals conflate the closed-domain and closed-world assumption, and therefore are not suited to deal with the anonymous objects that are common in ontological reasoning. Many real-world applications, like processing electronic health records (EHRs), also contain a temporal dimension, and require efficient reasoning algorithms. Moreover, since medical data is not recorded on a regular basis, reasoners must deal with sparse data with potentially large temporal gaps. Our contribution consists of three main parts: Firstly, we introduce a new closed-world semantics for answering conjunctive queries with negation over ontologies formulated in the description logic ELH⊥, which is based on the minimal universal model. We propose a rewriting strategy for dealing with negated query atoms, which shows that query answering is possible in polynomial time in data complexity. Secondly, we introduce a new temporal variant of ELH⊥ that features a convexity operator. We extend this minimal-world semantics for answering metric temporal conjunctive queries with negation over the logic and obtain similar rewritability and complexity results. Thirdly, apart from the theoretical results, we evaluate minimal-world semantics in practice by selecting patients, based their EHRs, that match given criteria.
- Keywords (DE)
- Klinische Studien, Temporale Logik, Nicht-Monotones Schlussfolgern
- Keywords (EN)
- Clinical Trials, Patient Selection, Temporal Logics, Non-Monotonic Reasoning, Closed-World Reasoning
- Classification (DDC)
- 004
- Classification (RVK)
- ST 640
- ST 265
- Examiner
- Prof. Dr.-Ing. Franz Baader
- Prof. Dr. Alessandro Artale
- Awarding institution
- Technische Universität Dresden, Dresden
- Project sponsoring
- Deutsche Forschungsgesellschaft
Generating and Answering Ontological Queries (GoAsQ)
ID: 1122/19-1 - version
- angenommene Version / Postprint / Autorenversion
- URN Qucosa
- urn:nbn:de:bsz:14-qucosa2-737736
- Qucosa date of publication
- 10.02.2021
- Document type
- doctoral_thesis
- Document language
- English
- licence
- CC BY 4.0