T. Krennwallner:
"Combining Nonmonotonic Knowledge Bases for Modular and Distributed Knowledge-Based Information Systems";
Talk: International Workshop on Business Models, Business Rules and Ontologies (BuRO), Bressanone/Brixen, Italy (invited); 2010-09-21; in: "1st International Workshop on Business Models, Business Rules and Ontologies (BuRO 2010)", T. Eiter, A. El Ghali, S. Fernández, S. Heymans, T. Krennwallner, F. Lévy (ed.); Ontorule Project, (2010), 41.

The developments in information technology during the last decade have been rapidly changing the possibilities for data and knowledge access. To respect this, several declarative knowledge representation formalisms have been extended with the capability to access data and knowledge sources that are external to a knowledge base. Such knowledge sources can come in various forms and may be as simple as a query interface to a database up to a full-fledged knowledge base.

In this talk we present two formalisms that that are centered around Answer Set Programming and have been designed with multiple knowledge bases in mind. One is modular nonmonotonic logic programs (MLP), which take up the issue of combining modules of logic programs into a coherent framework. The other formalism is multi-context systems (MCS), which are concerned with integrating knowledge from heterogeneous and possibly nonmonotonic knowledge bases (the contexts) using bridge rules, and combine them to a system with a semantics for contextual reasoning. We will argue that MLPs have the potential to host other formalisms that are relevant for the Semantic Web, like hybrid languages that combine ontologies and rules. MCS on the other hand are well-suited for distributed scenarios, where we can only assume an interface to contextualized knowledge bases---e.g., description logic or default theories---and do not get access to the actual content of the individual context. Heterogeneous nonmonotonic multi-context systems and modular nonmonotonic logic programs provide a basis for advanced knowledge-based information systems, which are targeted in ongoing research projects. They have been developed by the KBS group of the Vienna University of Technology in cooperation with external colleagues.

This work has been supported by the Austrian Science Fund (FWF) projects P20840 & P20841, the EC ICT Integrated Project Ontorule (FP7 231875), and the Vienna Science and Technology Fund (WWTF) project ICT08-020.

http://ontorule-project.eu/attachments/075_buro2010-proceedings.pdf

Project Head Thomas Eiter:
Modulare HEX-Programme

Project Head Thomas Eiter:
ONOTRULE - ONTOlogies meet business RULEs

Project Head Thomas Eiter:
Schließen in hybriden Wissensbasen

Project Head Michael Fink:
Inconsistency Management for Knowledge-Integration Systems