RDF Gateway integrates information based on semantically equivalent RDF classes and properties.
This package highlights the power of RDF Gateway to dynamically integrate disparate information based on semantics (semantic integration). Semantic integration eliminates the need for all systems to share a common schema in order to exchange information. In a highly distributed world, it is common practice for various organizations to develop and implement systems each using a different schema to describe their information. RDF Gateway can map queries, data sources, and results between schemas in such a way that to each individual system it appears that all other systems share its schema.
The rapid growth in computing power and the Internet along with the increasing decentralization of organizational structures has led to the creation of a vast interconnected network of distributed electronic information. This overall trend has made a wealth of information available to individuals and organizations. However the task of integrating disparate and distributed information has proven to be burdensome and costly.
The Extensible Markup Language (XML) has served as a good standard for systems to exchange information. The downside of XML is that all systems must use a common schema to describe their information. This is a difficult requirement when integrating systems between organizations and often requires special purpose gateways to convert information between schemas.
The Semantic Web initiative has produced a new standard called the Resource Description Framework (RDF). RDF is based on XML but provides well-defined semantics for the information it describes. This allows systems to dynamically integrate information described in different schemas by mapping semantically equivalent information. For example, RDF can assert that an employee is a person so that two systems that describe information in terms of employees and persons can exchange information.
RDF Gateway is a platform that can provide systems with semantic integration services. It can process a query expressed in terms of one schema by querying multiple information sources described in different schemas. RDF Gateway performs all this dynamically by using its logical inference capabilities to map RDF schemas based on semantics. The net effect is to each system it appears that all other systems share the same schema.
For example, take three systems A, B, and C as shown in the figure above. Each supports a different schema respectively based on customers, employees, and persons. System C can express a query in terms of persons and RDF Gateway will return information on persons by querying systems A and B for customers and employees respectively. It does so by performing a deductive search of semantically equivalent classes and properties based on RDF schemas.
This package will demonstrate this example.
Package Overview
Client Application
Data Sources
Inference Rules
Installing and Running the Sample
Appendix: Source Files