Abstract: When different agents communicate with each other, there needs to be
some way to ensure that the meaning of what one agent embodies is accurately
conveyed to another agent. It has been argued that ontologies play a key role
in communication among different agents. However, in many situations, because
there exist terminological heterogeneities and incompleteness of pieces of
information among ontologies used by different agents, communication among
agents will be very complex and difficult to tackle. In this paper, we propose
a solution to the problem for these situations. We use distributed description
logics (DDL) to model the mappings between ontologies used by different agents
and further make a default extension to DDL for default reasoning. An adapted
algorithm is proposed for checking default satisfiability of
ALC-concepts. Base on the default extension of the DDL model, a complete
information query can be reduced to checking default satisfiability of
the complex concept corresponding to the query.
