Ralph Hodgson and Willie Milnor, TopQuadrant
Currently, one of the most practical application spaces for Semantic Web technologies is creating an ontological layer over existing legacy databases.
Such layering allows flexible applications to be built without the cost of restructuring large amounts of data while maintaining the performance advantages of a relational database.
Whereas applications designed to directly query a database encode business logic in specific queries, ontological layer offers a flexible framework whereby dynamically generated queries are resilient to schema changes.
This same approach can be used to query multiple decentralized databases from a seemingly centralized point of view, allowing access to multiple database schemas via a single interface.
In an ontology, Semantic Web technologies such as RDFS, OWL and SWRL can be used to specify composition rules and abstractions, making it possible to answer complex questions without developing complex queries.
TopQuadrant has applied this approach to develop and deploy a flexible
faceted search system over a network of large, decentralized legacy
databases. The system uses ontologies in two distinct ways: as an
abstraction layer over an underlying relational data model; and as a search interface model driving the system itself.
This model-based approach allows dynamic system configuration simply through changes to the model.
The model controls what data can be searched, what facets can be used for building queries, and even how data should be displayed.
The system combines the structured power of ontologies with more
conventional keyword-based search over a related unstructured document
corpus. The resulting hybrid system provides capabilities beyond what is possible with either approach alone.
This talk will describe the process used for developing the ontological
layer; discuss challenges and technical solutions in integrating the
databases and bringing together structured and unstructured search. We will also show the benefits of using ontology to specify the search interface and interaction
About the Speakers
Ralph Hodgson is an Executive Partner and co-founder of TopQuadrant, a
company specializing in the Semantic Web tools and consulting services.
After having pioneered the adoption of Object Technology in Europe and the US, Ralph is now doing the same for semantic technology.
He is currently working with NASA on the use of Semantic Web standards for the return to the Moon and flight missions to Mars initiatives.
Ralph is a frequent speaker at IT conferences and a published author with over 30 articles and two books.
Willie Milnor is a Semantic Solutions developer with TopQuadrant where he implements enterprise systems for TopQuadrant's customers.
In addition to his software development work, Willie often assists in teaching TopQuadrant's training program "Getting Started with the Semantic Web".
Before joining TopQuadrant, he developed content management systems and a portal for a scientific encyclopedia.
He received a MS (2005) from UGA where he worked as a Research Assistant in the LSDIS lab