Ontomet: Ontology Metadata Framework

Proper description of data, or metadata, is important to facilitate data sharing among Geospatial Information Communities. To avoid the production of arbitrary metadata annotations, communities agree that creating or adopting a metadata specification is needed. The specification is a document, such as the Geographic Metadata Standard (ISO 19115-2003), which provides a set of rules for the proper use of metadata elements. When a community is adopting a metadata specification it has two main concerns: 1) how can an existing specification be adopted, so that elements can be restricted and domain vocabularies be used? and 2) how can a metadata specification be mapped withanother one to achieve interoperability? The two aforementioned concerns are raised due to the fact that: 1) specifications lack domain-specific elements, 2) specifications have limited extensibility, 3) specifications do not always solve semantic heterogeneities and 4) methodologies to create crosswalks among specification have not been formalized. The main goal of this thesis is to present a feasible solution for these problems by providing a flexible environment to allow interoperations of formalized metadata specifications, extensions, crosswalks and domain vocabularies. The main contributions of this thesis are: 1) creation of an abstract model to represent metadata specifications, 2) development of a methodology to extend metadata specifications, called Dynamic Community Profile, and 3) formalization of semantic mappings to perform complex and contextual metadata crosswalks. These three main contributions are encapsulated in a framework called Ontology- Metadata Framework or ONTOMET. ONTOMET has seven components: metadata specification, a domain vocabulary, top-domain ontology, metadata crosswalk, Dynamic Community Profile and vocabulary mapper. A Dynamic Community Profile is a metadata specification, which extends other metadata specifications and infer terms from controlled vocabularies. Vocabulary mappers solve semantic heterogeneities that appear in domain vocabularies and a metadata crosswalk expresses the semantic mappings of two specifications. Also strategies to conceptualize metadata specifications and vocabularies, are presented. Stand alone JAVA Tools and Web programs were created that implemented the methodologies presented, to allow creation of metadata instances and mappings, as well as views of hydrologic vocabularies to facilitate discovery of knowledge and resources in the Web.Ph.D., Civil Engineering -- Drexel University, 200