A5047265550- Semantic Web and Ontologies
- Advanced Database Systems and Queries
- Logic, Reasoning, and Knowledge
- Data Management and Algorithms
- Service-Oriented Architecture and Web Services
- Constraint Satisfaction and Optimization
- Logic, programming, and type systems
- Natural Language Processing Techniques
- Formal Methods in Verification
- Scientific Computing and Data Management
- Data Quality and Management
- Distributed systems and fault tolerance
- Complexity and Algorithms in Graphs
- Business Process Modeling and Analysis
- Advanced Algebra and Logic
- Web Data Mining and Analysis
- Algorithms and Data Compression
- semigroups and automata theory
- Cryptography and Data Security
- Advanced Data Storage Technologies
- DNA and Biological Computing
- Rough Sets and Fuzzy Logic
- Time Series Analysis and Forecasting
- AI-based Problem Solving and Planning
- Biomedical Text Mining and Ontologies
Birkbeck, University of London
2013-2024
University of London
2014-2015
Universidad de Londres
2015
Free University of Bozen-Bolzano
2009-2014
University of Liverpool
2011
King's College London
2004-2005
The recently introduced series of description logics under the common moniker `DL-Lite' has attracted attention logic and semantic web communities due to low computational complexity inference, on one hand, ability represent conceptual modeling formalisms, other. main aim this article is carry out a thorough systematic investigation inference in extensions original DL-Lite along five axes: by (i) adding Boolean connectives (ii) number restrictions concept constructs, (iii) allowing role...
We present Ontop, an open-source Ontology-Based Data Access (OBDA) system that allows for querying relational data sources through a conceptual representation of the domain interest, provided in terms ontology, to which are mapped. Key features Ontop its solid theor etical foundations, virtual approach OBDA, avoids materializing triples and is implemented query rewriting technique, extensive optimizations exploiting all elements OBDA architecture, compliance relevant W3C recommendations...
We present the framework of ontology-based data access, a semantic paradigm for providing convenient and user-friendly access to repositories, which has been actively developed studied in past decade. Focusing on relational sources, we discuss main ingredients key theoretical results, techniques, applications future challenges.
The use of ontologies for accessing data is one the most exciting new applications description logics in databases and other information systems. A realistic way realising sufficiently scalable ontology-based access practice by reduction to querying relational databases. In this paper, we describe combined approach, which incorporates given ontology into employs query rewriting eliminate spurious answers. We illustrate approach DL-Lite family briefly discuss results obtained EL family.
We design temporal description logics (TDLs) suitable for reasoning about conceptual data models and investigate their computational complexity. Our formalisms are based on DL-Lite with three types of concept inclusions (ranging from atomic disjointness to the full Booleans), as well cardinality constraints role inclusions. The interpreted over Cartesian products object domains flow time (ℤ, <), satisfying constant domain assumption. Concept TBox hold at all moments (globally), assertions...
We advocate datalogMTL, a datalog extension of Horn fragment the metric temporal logic MTL, as language for ontology-based access to log data. show that datalogMTL is EXPSPACE-complete even with punctual intervals, in which case MTL known be undecidable. Nonrecursive turns out PSPACE-complete combined complexity and AC0 data complexity. demonstrate by two real-world use cases nonrecursive programs can express complex concepts from typical user queries thereby facilitate Our experiments...
In this paper, we construct and investigate a hierarchy of spatio-temporal formalisms that result from various combinations propositional spatial temporal logics such as the logic PTL, RCC-8, BRCC-8, S4u their fragments. The obtained results give clear picture trade-off between expressiveness `computational realisability' within hierarchy. We demonstrate how different combining principles well primitives can produce NP-, PSPACE-, EXPSPACE-, 2EXPSPACE-complete, even undecidable out components...
It is known that for temporal languages, such as first-order LTL, reasoning about constant (time-independent) relations almost always undecidable. This applies to description logics well: binary together with general concept subsumptions in combinations of LTL and the basic logic ALC cause undecidability. In this paper, we explore extensions two recently introduced families 'weak' DL-Lite EL. Our results are twofold: temporalisations even rather expressive variants turn out be decidable,...