Frederico T. Fonseca

Ontologies and Knowledge Sharing in Urban GIS

Data and knowledge exchange among users of urban information systems presents many challenges. This paper discusses issues related to the use of ontologies in the development of urban geographic information systems and proposes the creation of software components from diverse ontologies as a way to share knowledge and data. These software components are derived from ontologies using an object-oriented mapping. The translation of an ontology into an active information system component leads to ontology-driven information systems and, in the specific case of geographic applications, to ontology-driven geographic information systems. We analyze the urban environment from the ontologists point of view and make some inferences about the relationship between knowledge and data sharing, and the theory of bona fide and fiat objects. We also discuss implementation issues, such as the use of Ontolingua as an ontology editor, and CORBA IDL generator, CORBA, and Java as object platforms.

Knowledge sharing in geographic information systems

The complexity and richness of geospatial data and the difficulty of their representation create specific problems for the interoperability of geographic information systems. This paper proposes the creation of software components from ontologies as a way to share knowledge and data. These software components are derived from ontologies using an object-oriented mapping. The translation of ontologies into active information system components leads to ontology-driven geographic information systems. The combined use of diverse ontologies and multiple inheritance leads to a discussion of implementation issues, such as the use of Ontolingua as an ontology editor, and CORBA and Java as object platforms.

Using the Internet to Access Geographic Information:An Open GIS Prototype

This project started with the objective of creating middleware to allow users to gain access to geographic data from several different sources, using a simple object-based model. The intention was to provide the widest possible range of users with easy and inexpensive access to public GIS data. The initial concept called for the development of an interface between the user and the GIS. Initially, this interface would only provide basic data access, and should evolve in the future to support the definition and implementation of more specialized services. However, the ability to connect simultaneously to different GIS platforms has been considered important to the success of the project.