Research | Matthias Knorr

Publications

Book Chapters

On Combining Ontologies and Rules. M. Knorr. In M. Simkus and I. Varzinczak (eds.) ReasoningWeb, Declarative Artificial Intelligence – 17th International Summer School 2021, Tutorial Lectures, 22-58, vol. 13100 of LNCS, Springer, 2022
Automated reasoning. M. Knorr. In R. Alhajj and J. Rokne (eds.) Encyclopedia of Social Network Analysis and Mining (2nd Ed.), Springer, 2018.
Description logics. M. Knorr and P. Hitzler, In D. M. Gabbay, J. H. Siekmann and J. Woods (eds.) Computational Logic, Vol. 9 of the Handbook of the History of Logic, Elsevier, 2014, 659-678. ISBN 13: 978-0-444-51624-4

Journals

Forgetting in Answer Set Programming - A Survey. R. Gonçalves, M. Knorr, and J. Leite, TPLP 23(1):111–156, 2023.
On the limits of forgetting in Answer Set Programming. R. Goncalves, M. Knorr, J. Leite, and S. Woltran, Artificial Intelligence, 286, 2020.
NoHR: An Overview. V. Kasalica, M. Knorr, J. Leite, and C. Lopes, Künstliche Intelligenz (2020).
A syntactic operator for forgetting that satisfies strong persistence. M. Berthold, R. Gonçalves, M. Knorr, and J. Leite, TPLP 19(5-6):1038-1055, 2019.
Reactive multi-context systems: Heterogeneous reasoning in dynamic environments. G. Brewka, S. Ellmauthaler, R. Gonçalves, M. Knorr, J. Leite, and J. Pührer, Artificial Intelligence, 256:68-104, 2018.
When you must forget: Beyond strong persistence when forgetting in answer set programming. R. Gonçalves, M. Knorr, J. Leite, and S. Woltran, TPLP, 17(5-6):837-854, 2017.
What if no hybrid reasoner is available. M. Knorr, M. Slota, J. Leite, and M. Homola, J. Log. Comput. 24(6):1279-1311, 2014.
Query-driven procedures for hybrid MKNF knowledge bases. J. J. Alferes, M. Knorr, and T. Swift, ACM Transactions in Computational Logic, 14(2):1-43, 2013.
Local closed world reasoning with description logics under the well-founded semantics. M. Knorr, J. J. Alferes, and P. Hitzler, Artificial Intelligence, 175(9-10):1528-1544, 2011.

Conferences

Revising Boolean Logical Models of Biological Regulatory Networks. F. Aleixo, M. Knorr, and J. Leite, KR 2023, 12-22.
Forgetting Web. M. Berthold, M. Knorr, and D. Odekerken, ICLP 2023 (Applications, Systems and Demo Track), 321-323.
Towards Provenance in Heterogeneous Knowledge Bases. M. Knorr, C. Damásio, R. Gonçalves, and J. Leite, LPNMR 2022, 287-300.
On Syntactic Forgetting Under Uniform Equivalence (Report). R. Gonçalves, T. Janhunen, M. Knorr, and J. Leite, ICLP 2022, 191-193.
Tractable Reasoning using Logic Programs with Intensional Concepts (Report). J. Heyninck, R. Gonçalves, M. Knorr, and J. Leite, ICLP 2022, 185-187.
On Syntactic Forgetting Under Uniform Equivalence. R. Gonçalves, T. Janhunen, M. Knorr, and J. Leite, JELIA 2021, 297-312.
Tractable Reasoning Using Logic Programs with Intensional Concepts. J. Heyninck, R. Gonçalves, M. Knorr, and J. Leite, JELIA 2021, 329-345.
Deep Neural Networks for Approximating Stream Reasoning with C-SPARQL. R. Ferreira, C. Lopes, R. Gonçalves, M. Knorr, L. Krippahl, and J. Leite, EPIA 2021, 338–350.
Faster Than LASER - Towards Stream Reasoning with Deep Neural Networks. J. Ferreira, D. Lavado, R. Gonçalves, M. Knorr, L. Krippahl, and J. Leite, EPIA 2021, 363–375.
Forgetting in Modular Answer Set Programming. R. Gonçalves, T. Janhunen, M. Knorr, J. Leite, and S. Woltran, AAAI 2019, 2843-2850.
Telco Network Inventory Validation with NoHR. V. Kasalica, I. Gerochristos, J.J. Alferes, A.S. Gomes, M. Knorr, J. Leite, LPNMR 2019, 18-31.
Forgetting in Answer Set Programming with Anonymous Cycles. M. Berthold, R. Gonçalves, M. Knorr, J. Leite, EPIA 2019, 552-565.
Variable Elimination for DLP-Functions. R. Gonçalves, T. Janhunen, M. Knorr, J. Leite, and S. Woltran, KR 2018, 643-644.
Integrating XSB Prolog with the OWL 2 profiles and beyond. C. Lopes, M. Knorr, and J. Leite, LPNMR 2017, 236-249.
Iterative variable elimination in ASP. R. Gonçalves, M. Knorr, and J. Leite, EPIA 2017, 643-656.
The ultimate guide to forgetting in answer set programming. R. Gonçalves, M. Knorr, and J. Leite, KR 2016, 135-144.
You can’t always forget what you want: on the limits of forgetting in answer set programming. R. Gonçalves, M. Knorr, and J. Leite, ECAI 2016, 957-965.
Inconsistency management in reactive multi-context systems. G. Brewka, S. Ellmauthaler, R. Gonçalves, M. Knorr, J. Leite, and J. Pührer, JELIA 2016, 529-535.
Forgetting in ASP: The forgotten properties. R. Gonçalves, M. Knorr, and J. Leite, JELIA 2016, 543-550.
Efficient paraconsistent reasoning with ontologies and rules. T. Kaminski, M. Knorr, and J. Leite, IJCAI-15, 3098-3105.
Next Step for NoHR: OWL 2 QL. N. Costa, M. Knorr, and J. Leite, ISWC 2015, 569-586.
Querying LUBM with non-monotonic features in Protégé using NoHR. N. Costa, M. Knorr, and J. Leite, ISWC 2015 (Posters & Demos).
Minimal change in evolving multi-context systems. R. Gonçalves, M. Knorr, and J. Leite, EPIA 2015, 611-623.
Reasoning over ontologies and non-monotonic rules. V. Ivanov, M. Knorr, and J. Leite, EPIA 2015, 388-401.
On efficient evolving multi-context systems. M. Knorr, R. Gonçalves, and J. Leite, PRICAI 2014, 284-296.
Preserving strong equivalence while forgetting. M. Knorr and J. J. Alferes, JELIA 2014, 412-425.
Evolving multi-context systems. R. Gonçalves, M. Knorr, and J. Leite, ECAI 2014, 375-380.
A query tool for EL with non-monotonic rules. V. Ivanov, M. Knorr, and J. Leite, ISWC 13, 215-231.
NoHR: querying EL with non-monotonic rules. V. Ivanov, M. Knorr, and J. Leite, ISWC 13 (Posters & Demos), 17-20.
Non-monotonic temporal goals. R. Gonçalves, M. Knorr, J. Leite, and Martin Slota, LPNMR 13, 374-386.
Forgetting under the well-founded semantics (short paper). J. J. Alferes, M. Knorr, and K. Wang, LPNMR 13, 36-41.
Recent advances in integrating OWL and rules (technical communication). M. Knorr, D. Carral Martínez, P. Hitzler, A. A. Krisnadhi, F. Maier, and C. Wang, RR 2012, 225-228.
Reconciling OWL and non-monotonic rules for the Semantic Web. M. Knorr, P. Hitzler, and F. Maier, ECAI 2012, 474-479. (Extended Version)
Normative systems require hybrid knowledge bases (extended abstract). M. Alberti, A. S. Gomes, R. Gonçalves, M. Knorr, J. Leite, and M. Slota, AAMAS 2012, 1425-1426.
Querying OWL 2 QL and non-monotonic rules. M. Knorr and J. J. Alferes, ISWC 2011, 338-353.
Querying in EL+ with nonmonotonic rules. M. Knorr and J. J. Alferes, ECAI 2010, 1079-1080.
Queries to hybrid MKNF knowledge bases through oracular tabling. J. J. Alferes, M. Knorr, and T. Swift, ISWC 2009, 1-16.
A coherent well-founded model for hybrid MKNF knowledge bases. M. Knorr, J. J. Alferes, and P. Hitzler, ECAI 2008, 99-103.
Towards tractable local closed world reasoning for the Semantic Web. M. Knorr, J. J. Alferes, and P. Hitzler, EPIA 2007, 3-14.

Workshops

Towards Explaining Actions of Learning Agents. B. Rodrigues, M. Knorr, L. Kripppahl, and R. Gonçalves, ALA 2023.
Modular Provenance in Multi-Context Systems. M. Knorr, C. Damásio, R. Gonçalves, and J. Leite, XLoKR 2022.
Obfuscating Knowledge in Modular Answer Set Programming. R. Gonçalves, T. Janhunen, M. Knorr, J. Leite, and S. Woltran, NMR2020.
Towards Efficient Reasoning with Intensional Concepts. J. Heyninck, R. Gonçalves, M. Knorr, and J. Leite, NMR2020.
On some properties of forgetting in ASP. R. Gonçalves, M. Knorr, and J. Leite, DARe 2016.
Towards inconsistency management in reactive multi-context systems. G. Brewka, S. Ellmauthaler, R. Gonçalves, M. Knorr, J. Leite, and J. Pührer, DARe 2016.
Well-founded paraconsistent semantics for hybrid theories composed of rules and ontologies. T. Kaminski, M. Knorr, and J. Leite, In JOWO 15, IJCAI workshop, 2015.
Extending NoHR for OWL 2 QL. N. Costa, M. Knorr, and J. Leite, In JOWO 15, IJCAI workshop, 2015.
Nonmonotonic nominal schemas revisited. M. Knorr, DL 2015.
Reasoning efficiently with ontologies and rules in the presence of inconsistencies (extended abstract), T. Kaminski, M. Knorr, and J. Leite, DL 2015.
Evolving bridge rules in evolving multi-context systems. R. Gonçalves, M. Knorr, and J. Leite, CLIMA XV, 2014, 52-69.
Minimal change in evolving multi-context systems (preliminary report). R. Gonçalves, M. Knorr, and J. Leite, ReactKnow at ECAI 2014.
Towards efficient evolving multi-context systems(preliminary report). M. Knorr, R. Gonçalves, and J. Leite, ReactKnow at ECAI 2014.
Time is up! - Norms with deadlines in action languages. M. Knorr, A. Gabaldon, R. Gonçalves, J. Leite, and M. Slota, CLIMA XIV, 2013, 223-238.
Towards action languages with norms and deadlines. M. Knorr, A. Gabaldon, R. Gonçalves, J. Leite, and M. Slota, NRAC’13.
MKNF knowledge bases in multi-context systems. M. Homola, M. Knorr, J. Leite, and M. Slota, CLIMA XIII, 2012, 146-162.
A comparison of disjunctive well-founded semantics. M. Knorr and P. Hitzler, FAInt at KI 2007.
A well-founded semantics for hybrid MKNF knowledge bases. M. Knorr, J. J. Alferes, and P. Hitzler, DL 2007.

Dissertations

Combining open and closed world reasoning for the Semantic Web. PhD Thesis, 2011.
A comparative study of disjunctive well-founded semantics. Master’s Thesis, 2006.
Level mapping characterizations for quantitative and disjunctive logic programs. Bachelor’s Thesis, 2003.

Projects

NEURASPACE (C626449889-0046305) - since April 2022
Sustainable Stone by Portugal (C644943391-00000051) - since April 2022
FORGET (PTDC/CCI-INF/32219/2017) - October 2018 - September 2022
DigForASP (COST Action 17124) - September 2018 - August 2020
RIVER (PTDC/CCI-INF/30952/2017) (as Principal Investigator) - August 2018 - July 2022
ABSOLV (028986/02/SAICT/2017)- July 2018 - June 2021
Bridging Theory and Practise: Update Semantics and Multi-shot ASP (FCT/3151/9/3/2017/S) - April 2017 - March 2019
ERRO (PTDC/EIA-CCO/121823/2010) - March 2012 - August 2015
ReDIK (FCT/2487/3/6/2011/S) - April 2011 - March 2013
REWERSE (NoE under FP6 - 506779) - March 2004 - February 2008

Events

Co-chair of the KRR track at EPIA 2022, Lisbon, 2021 (together with Pedro Cabalar, Eduardo Fermé, Ricardo Gonçalves, and Rafael Peñaloza)
Co-chair of the KRR track at EPIA 2021, virtual event, 2021 (together with Pedro Cabalar, Eduardo Fermé, Ricardo Gonçalves, and Rafael Peñaloza)
Co-chair of the KRR track at EPIA 2019, Vila Real, 2019 (together with Eduardo Fermé, Ricardo Gonçalves, Rafael Peñaloza, and Jörg Pührer)
Co-chair of the KRR track at EPIA 2017, Porto, 2017 (together with Ricardo Gonçalves, Minh Dao-Tran, and Jörg Pührer)

Software

NoHR Reasoner

Prizes

Prémio Científico IBM Portugal 2015