Publications

Journals

1. Virtual Knowledge Graphs: An Overview of Systems and Use Cases. Guohui Xiao, Linfang Ding, Benjamin Cogrel, Diego Calvanese. Data Intelligence. 2019.
2. Ontop-spatial: Ontop of Geospatial Databases. Konstantina Bereta, Guohui Xiao, and Manolis Koubarakis. Journal of Web Semantics. 2019.
3. Ontology-Based Access To Temporal Data With Ontop: A Framework Proposal. Elem Güzel Kalaycı, Sebastian Brandt, Diego Calvanese, Vladislav Ryzhikov, Guohui Xiao, and Michael Zakharyaschev. International Journal of Applied Mathematics and Computer Science. 2019.
4. VIG: Data Scaling for OBDA Benchmarks. Davide Lanti, Guohui Xiao, and Diego Calvanese. Semantic Web Journal. 2019.
5. Ontology-based Data Access - Beyond relational sources. Elena Botoeva, Diego Calvanese, Benjamin Cogrel, Julien Corman, Guohui Xiao. Intelligenza Artificiale. 2019.
6. Querying Log Data with Metric Temporal Logic. Sebastian Brandt, Elem Güzel Kalaycı, Vladislav Ryzhikov, Guohui Xiao, and Michael Zakharyaschev. Journal of Artificial Intelligence Research, 2018.
7. Ontop: Answering SPARQL Queries over Relational Databases. Diego Calvanese, Benjamin Cogrel, Sarah Komla-Ebri, Roman Kontchakov, Davide Lanti, Martin Rezk, Mariano Rodriguez-Muro, and Guohui Xiao. Semantic Web Journal. 2017 (SWJ 2016 Outstanding Paper Award) (opens new window)
8. Ontology Based Data Access in Statoil. Evgeny Kharlamov, Dag Hovland, Martin G. Skjæveland, Dimitris Bilidas, Ernesto Jiménez-Ruiz, Guohui Xiao, Ahmet Soylu, Davide Lanti, Martin Rezk, Dmitriy Zheleznyakov, Martin Giese, Hallstein Lie, Yannis E. Ioannidis, Yannis Kotidis, Manolis Koubarakis, Arild Waaler. Journal of Web Semantics, 2017.
9. Efficient SPARQL-to-SQL with R2RML mappings. Mariano Rodriguez-Muro and Martin Rezk, J. of Web Semantics. 2015
10. Optique --- zooming in on big data access. Martin Giese, Peter Haase, Ernesto Jiménez-Ruiz, Davide Lanti, Özgür Özçep, Martin Rezk, Riccardo Rosati, Ahmet Soylu, Guillermo Vega-Gorgojo, Arild Waaler, and Guohui Xiao. IEEE Computer. 2015

Conferences

1. The Virtual Knowledge Graph System Ontop. Guohui Xiao, Davide Lanti, Roman Kontchakov, Sarah Komla-Ebri, Elem Güzel-Kalayci, Linfang Ding, Julien Corman, Benjamin Cogrel, Diego Calvanese, and Elena Botoeva. ISWC (Resource), 2020.
2. Semantic Integration of Bosch Manufacturing Data Using Virtual Knowledge Graphs. Elem Güzel Kalaycı, Irlan Grangel Gonález, Felix Lösch, Guohui Xiao, Anees ul-Mehdi, Evgeny Kharlamov, and Diego Calvanese. ISWC (In-Use), 2020.
3. Enriching Ontology-based Data Access with Provenance. Diego Calvanese, Davide Lanti, Ana Ozaki, Rafael Penaloza, and Guohui Xiao. IJCAI, 2019.
4. Efficient Handling of SPARQL OPTIONAL for OBDA. Guohui Xiao, Roman Kontchakov, Benjamin Cogrel, Diego Calvanese, and Elena Botoeva. ISWC (Research), 2018.
5. Ontology-based data access: A survey. Guohui Xiao, Diego Calvanese, Roman Kontchakov, Domenico Lembo, Antonella Poggi, Riccardo Rosati, Michael Zakharyaschev. IJCAI. 2018.
6. Ontop-temporal: A Tool for Ontology-based Query Answering over Temporal Data. Elem Güzel Kalayci, Guohui Xiao, Vladislav Ryzhikov, Tahir Emre Kalayci, and Diego Calvanese. CIKM. 2018.
7. Efficient Ontology-Based Data Integration with canonical IRIs. Guohui Xiao, Dag Hovland, Dimitris Bilidas, Martin Rezk, Martin Giese, and Diego Calvanese. ESWC, 2018.
8. Cost-Driven Ontology-Based Data Access. Davide Lanti, Guohui Xiao, Diego Calvanese. ISWC (Research), 2017.
9. Semantic Rule-Based Equipment Diagnostics. Gulnar Mehdi, Evgeny Kharlamov, Ognjen Savkovic, Guohui Xiao, Elem Güzel Kalayci, Sebastian Brandt, Ian Horrocks, Mikhail Roshchin, Thomas A. Runkler. ISWC (In-Use), 2017. (Best In-Use Paper Award) (opens new window)
10. Ontology-Based Data Access with a Horn Fragment of Metric Temporal Logic. Sebastian Brandt, Elem Güzel Kalayci, Roman Kontchakov, Vladislav Ryzhikov, Guohui Xiao, Michael Zakharyaschev. AAAI, 2017.
11. Beyond OWL 2 QL in OBDA: Rewritings and Approximations. Elena Botoeva, Diego Calvanese, Valerio Santarelli, Domenico Fabio Savo, Alessandro Solimando and Guohui Xiao. AAAI, 2016.
12. Ontology-Based Data Access for Maritime Security. Stefan Brüggemann, Konstantina Bereta, Guohui Xiao and Manolis Koubarakis. ESWC (In-Use), 2016.
13. OBDA Constraints for Effective Query Answering. Dag Hovland, Davide Lanti, Martin Rezk and Guohui Xiao. RuleML, 2016.
14. Towards Practical OBDA with Temporal Ontologies (Position Paper). Diego Calvanese, Elem Güzel Kalayci, Vladislav Ryzhikov and Guohui Xiao. RR, 2016.
15. Ontology-based Integration of Cross-linked Datasets. Diego Calvanese, Martin Giese, Dag Hovland and Martin Rezk (ISWC 2015), 2015.
16. The NPD benchmark: Reality check for OBDA systems. Davide Lanti, Martin Rezk, Guohui Xiao, and Diego Calvanese. In Proc. of the 18th Int. Conf. on Extending Database Technology (EDBT 2015). ACM Press, 2015.
17. Answering SPARQL Queries over Databases and under OWL 2 QL Entailment Regime. Roman Kontchakov, Martin Rezk, Mariano Rodriguez-Muro, Guohui Xiao, and Michael Zakharyaschev. International Semantic Web Conference (ISWC), 2014.
18. Rules and Ontology Based Data Access. Guohui Xiao, Martin Rezk, Mariano Rodriguez-Muro, and Diego Calvanese. Eighth International Conference on Web Reasoning and Rule Systems, (RR), 2014.
19. High Performance Query Answering over DL-Lite Ontologies. Mariano Rodriguez-Muro, Diego Calvanese. KR 2012
20. Quest: Effcient SPARQL-to-SQL for RDF and OWL. Mariano Rodriguez-Muro, Josef Hardi, Diego Calvanese. ISWC (Posters & Demos) 2012

Workshops

1. Fast and Simple Data Scaling for OBDA Benchmarks. Davide Lanti, Guohui Xiao and Diego Calvanese. BLINK@ISWC, 2016.
2. OBDA Beyond Relational DBs: A Study for MongoDB. Elena Botoeva, Diego Calvanese, Benjamin Cogrel, Martin Rezk and Guohui Xiao. Description Logics, 2016.
3. The ontop framework for ontology based data access. Timea Bagosi, Diego Calvanese, Josef Hardi, Sarah Komla-Ebri, Davide Lanti, Martin Rezk, Mariano Rodriguez-Muro, Mindaugas Slusnys, and Guohui Xiao. CSWS (Posters and Demos), Wuhan, China, August 2014.
4. The NPD benchmark for OBDA systems. Davide Lanti, Martin Rezk, Mindaugas Slusnys, Guohui Xiao, and Diego Calvanese. SSWS 2014
5. A scalable benchmark for OBDA systems: Preliminary report. Diego Calvanese, Davide Lanti, Martin Rezk, Mindaugas Slusnys, and Guohui Xiao. ORE 2014
6. Query Rewriting and Optimisation with Database Dependencies in Ontop. Mariano Rodriguez-Muro, Roman Kontchakov, Michael Zakharyaschev: Description Logics 2013
7. Evaluating SPARQL-to-SQL Translation in Ontop. Mariano Rodriguez-Muro, Martín Rezk, Josef Hardi, Mindaugas Slusnys, Timea Bagosi, Diego Calvanese: ORE 2013
8. OBDA with Ontop. Mariano Rodriguez-Muro, Roman Kontchakov, Michael Zakharyaschev: ORE 2013
9. Ontop at Work. Mariano Rodriguez-Muro, Roman Kontchakov, Michael Zakharyaschev. OWLED 2013
10. On Rewriting, Answering Queries in OBDA Systems for Big Data (Short Paper). Diego Calvanese, Ian Horrocks, Ernesto Jiménez-Ruiz, Evgeny Kharlamov, Michael Meier, Mariano Rodriguez-Muro, Dmitriy Zheleznyakov. OWLED 2013
11. Quest, an OWL 2 QL Reasoner for Ontology-based Data Access. Mariano Rodriguez-Muro, Diego Calvanese. OWLED 2012

Tutorials and Demos

1. Destination Tutorial (opens new window) given at the Knowledge Graph Conference 2021 by Diego Calvanese, Benjamin Cogrel and Guohui Xiao.
2. Novel Developments in Ontology-Based Data Access and Integration (NOBDI) (opens new window) Diego Calvanese, Benjamin Cogrel and Guohui Xiao. Full day tutorial, 17th International Conference of the Italian Association for Artificial Intelligence -- Trento, November 20-23, 2018.
3. Semantic Technologies for Data Access and Integration. Diego Calvanese and Guohui Xiao. Full day tutorial, CIKM. Torino, 26 October 2018.
4. Ontology-based Data Access: Theory and Practice (opens new window). Guohui Xiao and Roman Konchakov. Full day tutorial, IJCAI 2018 Tutorial. Stockholm, July 14, 2018.
5. Mapping Management and Expressive Ontologies in Ontology-Based Data Access (opens new window). Diego Calvanese, Benjamin Cogrel and Guohui Xiao. Full day tutorial, EKAW. Bologna, November 19, 2016.
6. Ontology-Based Data Access with Ontop (opens new window). Benjamin Cogrel. Lecture at the ESSLLI summer school, 2016.
7. Ontop: Answering SPARQL Queries over Relational Databases (opens new window). Guohui Xiao. Stanford, 2016.
8. Ontology-based Data Access: From Theory to Practice (opens new window) (Diego Calvanese, Martin Rezk, Guohui Xiao. ISWC 2015 Tutorial)
9. Ontology-based data access --- Theory and Practice (opens new window). (Guohui Xiao, Summer School at CSWS2014, Wuhan, China)
10. An Introduction to Description Logics and Query Rewriting. (opens new window) Roman Kontchakov, Michael Zakharyaschev. Reasoning Web 2014
11. Ontology-Based Data Access with Databases: A Short Course. (opens new window) (Roman Kontchakov, Mariano Rodriguez-Muro, Michael Zakharyaschev. Reasoning Web 2013)
12. Ontop: A Tutorial (opens new window) (Mariano Rodriguez-Muro, Vienna'13)

Master theses

• Lukas Sundqvist: Extending VKG Systems with RDF-star Support (opens new window), Free University of Bozen-Bolzano, March 2022.