TROn - Tractable Reasoning with Ontologies

Project funded by the National Science Foundation under award 1017225 III: Small.
September 2010 to August 2013.

PI: Pascal Hitzler, Knowledge Engineering Lab, Ohio Center of Excellence in Knowledge-enabled Computing (Kno.e.sis), Wright State University, Dayton, Ohio.

Description

The Semantic Web is based on describing the meaning - or semantics - of data on the Web by means of metadata - data describing other data - in the form of ontologies. The World Wide Web Consortium (W3C) has made several recommended standards for ontology languages which differ in expressivity and ease of use. Central to these languages is that they come with a formal semantics, expressed in model-theoretic terms, which enables access to implicit knowledge by automated reasoning. Progress in the adoption of reasoning for ontology languages in practice is currently being made, but several obstacles remain to be overcome for wide adoption on the Web. Two of the central technical issues are scalability of reasoning algorithms, and dealing with inconsistency of the ontological knowledge bases. These two issues are being addressed in this project.

The scalability issue has its origin in the fact that the expression of complex knowledge requires sophisticated ontology languages, like the Web Ontology Language OWL, which are inherently difficult to reason with - as witnessed by high computational complexities, usually ExpTime or beyond. This project builds on recent new developments in polynomial time languages around OWL in order to remedy this. In particular, in this project efficient algorithmizations and tools are developed for the largest currently known polynomial-time ontology language, called SROELVn. Reasoning with knowledge bases with expressivity beyond SROELVn is enabled through approximating these knowledge bases within SROELVn.

The inconsistency issue has its origin in the fact that large knowledge bases, in particular on the web, are usually not centrally engineered, but arise out of the merging of different knowledge bases with different underlying perspectives and rationales. In this project tools are developed for efficient, i.e., polynomial-time reasoning with inconsistent ontologies.

The concrete outcome of the project is an open source reasoning system which is able to reason efficiently with (possibly) inconsistent knowledge bases around OWL, in at least an approximate manner.

Publications

• Paraconsistent OWL and Related Logics.
  Frederick Maier, Yue Ma, Pascal Hitzler
  Semantic Web journal.
  To appear.
  [pdf (paper)]
• Complexity of Horn Description Logics.
  Markus Krötzsch, Sebastian Rudolph, Pascal Hitzler
  ACM Transactions on Computational Logic.
  To appear.
  [pdf (technical report)]
• Local Closed World Reasoning: Grounded Circumscription for OWL.
  Kunal Sengupta, Adila Krisnadhi, Pascal Hitzler
  In: L. Aroyo, C. Welty, H. Alani, J. Taylor, A. Bernstein, L. Kagal, N. F. Noy, E. Blomqvist (Eds.): The Semantic Web - ISWC 2011 - 10th International Semantic Web Conference, Bonn, Germany, October 23-27, 2011, Proceedings, Part I. Lecture Notes in Computer Science Vol. 7031, Springer, Heidelberg, 2011, pp. 617-632.
  [pdf (paper)]
• Representation of Parsimonious Covering Theory in OWL-DL.
  Cory Henson, Krishnaprasad Thirunarayan, Amit Sheth, Pascal Hitzler
  In: M. Dumontier and M. Courtot (eds.), Proceedings of the 8th International Workshop on OWL: Experiences and Directions (OWLED 2011) San Francisco, California, USA, June 5-6, 2011. CEUR Workshop Proceedings Vol. 796.
• Local Closed World Semantics: Keep it simple, stupid!
  Adila Krisnadhi, Kunal Sengupta, Pascal Hitzler
  In: Riccardo Rosati, Sebastian Rudolph, Michael Zakharzaschev, Proceedings of the 2011 International Workshop on Description Logics (DL2011), Barcelona, Spain, July 2011. CEUR Workshop Proceedings, Vol. 745.
  [pdf (technical report)]
• Nominal Schemas for Integrating Rules and Description Logics.
  Markus Krötzsch, Frederick Maier, Adila Alfa Krisnadhi, Pascal Hitzler
  In: Riccardo Rosati, Sebastian Rudolph, Michael Zakharzaschev, Proceedings of the 2011 International Workshop on Description Logics (DL2011), Barcelona, Spain, July 2011. CEUR Workshop Proceedings, Vol. 745.
  
• OWL and Rules.
  Adila Alfa Krisnadhi, Frederick Maier, Pascal Hitzler
  In: A. Polleres, C. d'Amato, M. Arenas, S. Handschuh, P. Kroner, S. Ossowski, P.F. Patel-Schneider (eds.), Reasoning Web. Semantic Technologies for the Web of Data. 7th International Summer School 2011, Galway, Ireland, August 23-27, 2011, Tutorial Lectures. Lecture Notes in Computer Science Vol. 6848, Springer, Heidelberg, 2011, pp. 382-415.
  [pdf (technical report)]
• Syntax Proposal for Nominal Schemas.
  David Carral Martinez, Adila A. Krisnadhi, Pascal Hitzler
  Technical Report, Kno.e.sis Center, Wright State University, July 2011.
  [pdf (technical report)]
• Reconciling OWL and Rules.
  David Carral Martinez, Adila Krisnadhi, Frederick Maier, Kunal Sengupta, Pascal Hitzler
  Technical Report, Kno.e.sis Center, Wright State University, Dayton, Ohio, U.S.A., June 2011.
  [pdf (technical report)]
• Contextual Ontology Alignment of LOD with an Upper Ontology: A Case Study with Proton.
  Prateek Jain, Peter Z. Yeh, Kunal Verma, Reymonrod G. Vasquez, Mariana Damova, Pascal Hitzler, Amit P. Sheth
  In: Grigoris Antoniou, Marko Grobelnik, Elena Paslaru Bontas Simperl, Bijan Parsia, Dimitris Plexousakis, Pieter De Leenheer, Jeff Pan (Eds.): The Semantic Web: Research and Applications - 8th Extended Semantic Web Conference, ESWC 2011, Heraklion, Crete, Greece, May 29-June 2, 2011, Proceedings, Part I. Lecture Notes in Computer Science 6643, Springer, 2011, pp. 80-92.
  [pdf (paper)]
• A Better Uncle For OWL - Nominal Schemas for Integrating Rules and Ontologies.
  Markus Krötzsch, Frederick Maier, Adila Alfa Krisnadhi, Pascal Hitzler
  In: S. Sadagopan, Krithi Ramamritham, Arun Kumar, M.P. Ravindra, Elisa Bertino, Ravi Kumar (eds.), WWW '11 20th International World Wide Web Conference, Hyderabad, India, March/April 2011. ACM, New York, 2011, pp. 645-654.
  [pdf (paper)]
• What's happening in Semantic Web ... and what FCA could have to do with it.
  Pascal Hitzler
  In: P. Valtchev and R. Jäschke (Eds.): Formal Concept Analysis, 9th International Conference, ICFCA 2011, Nicosia, Cyprus, May 2011, Proceedings. Lecture Notes in Artificial Intelligence 6628, Springer, Heidelberg, pp. 18-23.
• Local closed world semantics: grounded circumscription for description logics.
  Adila Krisnadhi, Kunal Sengupta, Pascal Hitzler
  In: C. Gutierrez, S. Rudolph (Eds.), Web Reasoning and Rule Systems. 5th International Conference, RR 2011, Galway, Ireland, August 29-30, 2011, Proceedings. Lecture Notes in Computer Science Vol. 6902, Springer, Heidelberg, 2011, pp. 263-268.
• Paraconsistent Semantics for Hybrid MKNF Knowledge Bases.
  Shasha Huang, Qingguo Li, Pascal Hitzler
  In: C. Gutierrez, S. Rudolph (Eds.), Web Reasoning and Rule Systems. 5th International Conference, RR 2011, Galway, Ireland, August 29-30, 2011, Proceedings. Lecture Notes in Computer Science Vol. 6902, Springer, Heidelberg, 2011, pp. 93-107.
  [pdf (paper)] [pdf (extended technical report)]
• Local Closed-World Reasoning with Description Logics under the Well-founded Semantics.
  Matthias Knorr, Jose Julio Alferes, Pascal Hitzler
  Artificial Intelligence 175(9-10), 2011, 1528-1554.
  [pdf (technical report)] [publisher version]

Other Resources

Information about extending OWL with rules using nominal schemas.