3 citations · 9 across the 11 of their papers we have counts for
12 papers
Certain Answers to a SPARQL Query over a Knowledge Base (extended version)
Julien Corman, Guohui Xiao
Ontology-Mediated Query Answering (OMQA) is a well-established framework to answer queries over an RDFS or OWL Knowledge Base (KB). OMQA was originally designed for unions of conju…
Enriching Ontology-based Data Access with Provenance (Extended Version)
Diego Calvanese, Davide Lanti, Ana Ozaki +2
Ontology-based data access (OBDA) is a popular paradigm for querying heterogeneous data sources by connecting them through mappings to an ontology. In OBDA, it is often difficult t…
Efficient Handling of SPARQL OPTIONAL for OBDA (Extended Version)
Guohui Xiao, Roman Kontchakov, Benjamin Cogrel +2
OPTIONAL is a key feature in SPARQL for dealing with missing information. While this operator is used extensively, it is also known for its complexity, which can make efficient eva…
BigSR: an empirical study of real-time expressive RDF stream reasoning on modern Big Data platforms
Xiangnan Ren, Olivier Curé, Hubert Naacke +1
The trade-off between language expressiveness and system scalability (E&S) is a well-known problem in RDF stream reasoning. Higher expressiveness supports more complex reasoning lo…
Cost-Driven Ontology-Based Data Access (Extended Version)
Davide Lanti, Guohui Xiao, Diego Calvanese
In ontology-based data access (OBDA), users are provided with a conceptual view of a (relational) data source that abstracts away details about data storage. This conceptual view i…
Querying Log Data with Metric Temporal Logic (Technical Report)
Sebastian Brandt, Elem Güzel Kalaycı, Vladislav Ryzhikov +2
We propose a novel framework for ontology-based access to temporal log data using a datalog extension datalogMTL of a Horn fragment of the metric temporal logic MTL. We show that d…
Metric Temporal Logic for Ontology-Based Data Access over Log Data
Diego Calvanese, Elem Güzel Kalaycı, Vladislav Ryzhikov +2
We present a new metric temporal logic HornMTL over dense time and its datalog extension datalogMTL. The use of datalogMTL is demonstrated in the context of ontology-based data acc…
Data Scaling in OBDA Benchmarks: The VIG Approach
Davide Lanti, Guohui Xiao, Diego Calvanese
In this paper we describe VIG, a data scaler for benchmarks in the context of ontology-based data access (OBDA). Data scaling is a relatively recent approach, proposed in the datab…
OBDA Constraints for Effective Query Answering (Extended Version)
Dag Hovland, Davide Lanti, Martin Rezk +1
In Ontology Based Data Access (OBDA) users pose SPARQL queries over an ontology that lies on top of relational datasources. These queries are translated on-the-fly into SQL queries…
Expressivity and Complexity of MongoDB (Extended Version)
Elena Botoeva, Diego Calvanese, Benjamin Cogrel +1
A significant number of novel database architectures and data models have been proposed during the last decade. While some of these new systems have gained in popularity, they lack…
Beyond OWL 2 QL in OBDA: Rewritings and Approximations (Extended Version)
Elena Botoeva, Diego Calvanese, Valerio Santarelli +3
Ontology-based data access (OBDA) is a novel paradigm facilitating access to relational data, realized by linking data sources to an ontology by means of declarative mappings. DL-L…
A Paraconsistent Tableau Algorithm Based on Sign Transformation in Semantic Web
Xiaowang Zhang, Guohui Xiao, Zuoquan Lin
In an open, constantly changing and collaborative environment like the forthcoming Semantic Web, it is reasonable to expect that knowledge sources will contain noise and inaccuraci…