Semantic framework for free-form search of Grid resources and services

If the model of free-form queries, which has proved successful for HTML-based search on the Web, is made available for grid services, it will serve as a powerful tool for scientists to retrieve information on resources, monitoring data, replica location sets, and meta-data on scientific data sets, etc., in an intuitive manner. To enable this vision, there is a critical need to design and develop tools that abstract away the fundamental complexity of XML-based grid specifications and toolkits, and provide an elegant, simple, and powerful free-form query-based invocation system to end users. Current implementations of XML-based grid service descriptions require end users to have intimate knowledge of service descriptions, related toolkits, and query languages. We present the design, implementation, and performance analysis of our ontological framework that employs matching algorithms, automated extension of ontologies, and optimizations to match free-form user queries with corresponding operations in grid services and resource information stored in RDF/OWL format. Our system uses semantic Web concepts, ontologies, and lexical tools to automate discovery and matchmaking of grid services and resource information. We quantify the performance improvements due to knowledge acquisition and extension of ontology files with each missed query, and present precision and recall studies to measure the accuracy of the free-form search.