Applying Reasoning to Instance Transformation.

Significant effort has been invested by the Semantic Web community in methodologies and tools for creating ontology mappings. Various techniques for mapping creation have been developed; however less interest has been shown in the actual usage of the created mappings and their application in concrete mediation scenarios. In this paper we show how mappings can be converted to logical rules and evaluated by a Datalog reasoner in order to produced the desired mediation result. The mediation scenario discussed in this work is instance transformation: data expressed as ontology instances is transformed from the terms of one ontology in to the terms of another ontology based on mappings created in a design-time phase. We analyze the required reasoning task and describe how the mappings created at design-time can be grounded at runtime. We also explore strategies and techniques that we employed in order to improve the efficiency of the overall process.