Semantic Framework in EEG/ERP Portal

Our research group specializes in research of brain activity. We widely use methods of encephalography (EEG) and event-related potentials (ERP). Since a collection of obtained data/metadata gradually grows we had to solve their long term storage and management. As a solution we developed the EEG/ERP Portal as a core of a complete software infrastructure supporting EEG/ERP research. Since we are working on the registration of the EEG/ERP Portal as a recognizable data source within NIF we provide the stored experiments in the form of the Semantic Web structures. Since the EEG/ERP Portal is a Java-based application with the data layer using common JavaBeans we are simultaneously developing the Semantic Framework that transforms input JavaBeans into the Semantic Web languages.
The Semantic Framework is being developed as a single library. It is used as a black box with the input in the form of a set of JavaBeans and the output in the form of an ontology document. The ontology document can be serialized into several supported syntaxes. We currently support RDF/XML, OWL/XML, Turtle, and abbreviated OWL/XML formats.

The Semantic Framework contains three subcomponents. The first subcomponent is the Extended JenaBean. Because of semantic gaps between object-oriented and Semantic Web models we proposed and implemented an extension of common JavaBean using Java Annotations. The output of the extended JenaBean component is an internal model representation. This representation is submitted to the second, Ontology Model Creator, subcomponent. This subcomponent creates an Ontology model. The internal JenaBean model is processed and an ontology document is created by calling Jena API methods. The result model can be further processed by the last subcomponent OWL API that transforms the ontology model into the supported ontology formats.

The Semantic Framework is integrated in the EEG/ERP Portal where it is controlled by a build-in timer. The timer calls the Semantic Framework API in regular intervals. The API generates the ontology document from the stored experiments. The ontology document is stored in a temporary file. When any document request appears the temporary file containing the actual set of stored experiments is immediately available.

Acknowledgements
This work was supported by the European Regional Development Fund (ERDF), Project "NTIS – New Technologies for Information Society", European Centre of Excellence, CZ.1.05/1.1.00/02.0090.