Section: New Results

Ontology matching and alignments

We pursue our work on ontology matching and alignment support [8] [10] with contributions to evaluation and alignment semantics.

Evaluation

Participant : Jérôme Euzenat.

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 [2] .

This year, we ran the oaei 2014 evaluation campaign [15] . We used again our generator for generating new version of benchmarks. The Alignment api was used for manipulating alignments and evaluating results.

A novelty of this year was that data interlinking evaluation was using the seals platform and a new query-based evaluation track was created.

The participating systems and evaluation results were presented in the 9th Ontology Matching workshop, held in Riva de Garda, Italy. More information on oaei can be found at http://oaei.ontologymatching.org/ .

Algebras of alignment relations

Participants : Armen Inants [Correspondent] , Jérôme Euzenat.

Qualitative calculus is the central concept 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. We tackle the problem of combining two or more calculi over disjoint universes into a single calculus. The problem is important, because in the ontology matching domain we deal with various kinds of ontological entities: concepts, individuals, properties. We define a new formalism called a heterogeneous qualitative calculus, based on an algebraic construct called Schröder category. A Schröder category is to binary relations over heterogeneous universes what a relation algebra is to homogeneous ones. We establish the connection between homogeneous and heterogeneous qualitative calculi by defining two mutually inverse transition operators. We provide an algorithm for combining two homogeneous calculi with different universes into a single calculus.

This work has vocation to support developments of the Alignment api towards relation algebras. It is part of the PhD of Armen Inants.