The proliferation of spatial data on the Internet is beginning to allow a much wider access to data currently available in various Geographic Information Systems (GIS). In order t...
Traditionally, data that has both linear and hierarchical structure, such as annotated linguistic data, is modeled using ordered trees and queried using tree automata. In this pap...
Constructing and maintaining semantic mappings are necessary but troublesome in data sharing systems. While most current work focuses on seeking automated techniques to solve this...
Recent interests on XML, Semantic Web, and Web ontology, among other topics, have sparked a renewed interest on graph-structured databases. A fundamental query on graphs is the re...
We consider the navigational core of XPath, extended with two operators: the Kleene star for taking the transitive closure of path expressions, and a subtree relativisation operat...