Section: New Results

Ontology matching and alignments

We pursue our work on ontology matching and alignment support [4] with contributions to evaluation and the use of algebras of relations within alignments.

Evaluation

Participant : Jérôme Euzenat [Correspondent] .

Since 2004, we run the Ontology Alignment Evaluation Initiative (oaei ) which organises evaluation campaigns for assessing the degree of achievement of actual ontology matching algorithms [3] .

This year, we also handed out the organisation of oaei 2015 to Ernesto Jiménez Ruiz (University of Oxford). We used again our generator for generating new version of benchmarks. The Alignment api was used for manipulating alignments and evaluating results [8] .

The participating systems and evaluation results were presented in the 10th Ontology Matching workshop [13] , held Bethleem (PA US). More information on oaei can be found at http://oaei.ontologymatching.org/ .

Algebras of alignment relations

Participants : Armen Inants [Correspondent] , Jérôme Euzenat.

Qualitative calculi are central in qualitative binary constraint satisfaction problems. All formalisms developed so far are homogeneous – they assume a single universe. We had previously shown the advantages of using a homogeneous qualitative calculus for expressing ontology alignment relations between concepts.

They make it possible to aggregate alignments disjunctively or conjunctively and to propagate alignments within a network of ontologies. The previously considered algebra of relations contains taxonomical relations between classes only. We have tackled the problem of combining two or more calculi over disjoint universes into a single calculus [9] . The problem is important because ontology matching deals with various kinds of ontological entities: concepts, individuals, properties. We have designed an algorithm for combining two homogeneous calculi with different universes into a single calculus. This has been applied to alignment relations [9] combining algebras for relations between concepts and individuals. It is, first, able to deal with empty classes, and, second, incorporates all qualitative taxonomical relations that occur between individuals and concepts, including the relations “is a” and “is not”. We have proved that this algebra is coherent with respect to the simple semantics of alignments.

The proposed algebras of relations and others have been integrated within the Alignment api (§ 6.1 ).

This work is part of the PhD of Armen Inants.