## Section: New Results

### Ontology matching and 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 used again our generator for generating a 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 11th Ontology Matching workshop [14], [15], held Kobe (JP). More information on oaei can be found at http://oaei.ontologymatching.org/.

#### Algebras of alignment relations

Participants : Manuel Atencia Arcas, Jérôme Euzenat [Correspondent] , Armen Inants.

Qualitative calculi are central in qualitative binary constraint satisfaction problems. All these qualitative calculi share an implicit assumption that the universe is homogeneous, i.e., consists of objects of the same kind. However, objects of different kinds may also entertain relations. Many applications discriminate between different kinds of objects. For example, some spatial models discriminate between regions, lines and points, and different relations are used for each kind of objects. In ontology matching, qualitative calculi were shown useful for expressing alignments between only one kind of entities, such as concepts or individuals. However, relations between individuals and concepts, which impose additional constraints, are not exploited.

We introduced modularity in qualitative calculi and provided a methodology for modeling qualitative calculi with heterogeneous universes [5]. It is based on a special class of partition schemes which we call modular. For a qualitative calculus generated by a modular partition scheme, we can define a structure that associates each relation symbol with an abstract domain and codomain from a Boolean lattice of sorts. A module of such a qualitative calculus is a sub-calculus restricted to a given sort, which is obtained through an operation called relativisation to a sort. Of a greater practical interest is the opposite operation, which allows for combining several qualitative calculi into a single calculus. We defined an operation called combination modulo glue, which combines two or more qualitative calculi over different universes, provided some glue relations between these universes. The framework is general enough to support most known qualitative spatio-temporal calculi.

In 2012, we introduced a semantics supporting confidences in correspondences as weights. However, it introduced a discontinuity between weighted and non-weighted interpretations. Moreover, it does not provide a calculus for reasoning with weighted ontology alignments. We introduced a calculus for such alignments [11] provided by an infinite relation-type algebra, the elements of which are weighted taxonomic relations. In addition, it approximates the non-weighted case in a continuous manner.

This work has been part of the PhD of Armen Inants [5] partially funded by the Lindicle project (§7.1.1).