Ontology Engineering and Ontological Data Access

Carsten Lutz (University of Bremen).

Course Summary | About the lecturer | Location and schedule | Materials | Assignment

Course summary:

In artificial intelligence, ontologies are used to capture the knowledge of an application domain. They constitute a core component of `intelligent' systems and also play an important role in querying data that is incomplete and heterogeneous, arising in prominent applications such as web data extraction and data integration. In this lecture series, I start with an introduction to ontologies and to description logics as a widely used class of ontology languages, illustrating some basic reasoning problems and techniques, and discussing computational complexity pitfalls. I will then add data to the picture, introducing the central notion of an ontology-mediated query (OMQ), that is, the combination of a traditional database query with an ontology. I survey fundamental properties of OMQs such as their complexity, expressive power, descriptive strength, and rewritability into traditional query languages such as SQL and Datalog. A central observation is that there is a close and fruitful connection between OMQs and constraint satisfaction problems (CSPs) as well as related fragments of monadic NP, which puts OMQs into a more general perspective and gives raise to a number of interesting results.

About the lecturer:

Carsten Lutz is a professor of computer science at the University of Bremen, Germany. He obtained his PhD from the University of Aachen in 2001 and his habilitation from TU Dresden in 2006. Since 2008, he is head of the research group "Theory of Artificial Intelligence" in Bremen. He is a coauthor of a recent textbook on description logics, received an ERC grant for working on ontology-mediated querying, and has published widely on this topic, winning best paper awards at both AI and database conferences.

Location and schedule:

MIMUW building, room TBA.

Wednesday, April 18, room 2180
14:15 - 15:45 lecture
15:45 - 16:00coffee and cake
16:00 - 17:00 class
Thursday, April 19,

room 1770

14:15 - 15:45 lecture
Friday, April 20, room 2180
14:15 - 15:45 lecture
15:45 - 16:00 coffee and cake
16:00 - 17:00 class
Saturday, April 20, room 2180
10:00 - 10:15 coffee and cake
10:15 - 11:30 lecture

Part 1
Part 2
Part 3
Part 4

Assignment: problem set. Please submit the solutions at the address clu@uni-bremen.de by May 27.