A SPARQL extension with spatial-temporal quantitative query

Since time and space play import roles in the research about KR (Knowledge Representation), spatial-temporal reasoning becomes one hot spot in knowledge reasoning. Ontology language is an excellent description language with which the knowledge can be well described. SPARQL can query knowledge in ontology, however, a few of them involve quantitative spatial-temporal relationships. In this paper, we choose event as research object and extend existing event model with time and space. We define 13 temporal relationships, 9 spatial azimuthal relationships and 8 spatial topological relationships quantitatively. Then, we extend SPARQL with 30 query operators, with which the certain relationship between two events can be calculated from property value of them. The experiment shows that, the SPARQL Extension with spatial-temporal quantitative query can effectively dig hidden relationships between entities in event ontology. Meanwhile, the effectiveness and performability are verified with this experiment.