Engineering a Replay Application Based on RDF and OWL

Digital Replay System (DRS) is an application for replaying and analyzing combinations of video recordings, transcriptions and system log files. The W3C’s Resource Description Framework (RDF) and Web Ontology Language (OWL) are used to define and maintain the application’s internal data model, based on the JENA RDF library. Each application has its own persistent RDF models, provided by a database-backed JENA model. A top-level division is made into “projects”, each of which has its own RDF model for scalability and manageability. An in-memory model cache and carefully limited use of inference yields acceptable interactive performance. OWL is used for data modeling, both for primary data objects used in the application, supported by a Java wrapper generating tool, and for more general descriptive metadata, accessed via ontology-driven generic interfaces. The RDF data model is complemented by relational databases for storing system events and XML-encoded files for editable “rich” documents. This has proved to be an effective – and transferable – implementation and data storage approach. DRS is available under an open source license.