We outline three known algorithms for relational division, the algebra operator used to express universal quantification (for-all conditions), and a new algorithm called Hash-Division. By comparing the algorithms analytically and experimentally, we show that the new algorithm provides performance competitive or superior to techniques used to-date, namely techniques using sorting or aggregate fu...

To optimize the efficiency of the geospatial service in the flood response decision making system, a Parallel Agent-as-a-Service (P-AaaS) method is proposed and implemented in the cloud. The prototype system and comparisons demonstrate the advantages of our approach over existing methods. The P-AaaS method includes both parallel architecture and a mechanism for adjusting the computational resou...

An ontology is a main component of an evolving knowledge base that caters to multiple clients. Consider a scenario where an automated procedure (a computer vision algorithm) used in an analyst tool detects different kinds of “roads” in images, and features in the ontology are used to distinguish a “paved” road from a “dirt road”. In another scenario, the ontology enables reasoning about “locati...

The purpose of the WFS specification, proposed by the the OpenGIS Consortium (OGC), is to describe the manipulation operations over geospatial data using GML. Web servers providing WFS service are called WFS Servers. Their objective is to provide queries, updates and exchange of geospatial data as geographic features instances encoded in GML. This work proposes an approach for automatic feature...

The mobile geospatial information service involves the domain of mobile communication, mobile computing, geospatial information service and other techniques. This paper focuses on the integration of spatial information and mobile communication technologies. The author proposes the architecture of mobile geospatial information service based on the Ad Hoc network. On the basis of this architectur...

An approach to improve an RCC-derived geospatial approximation is presented which makes use of concept inclusion axioms in OWL. The algorithm used to control the approximation combines hypothesis testing with consistency checking provided by a knowledge representation system based on description logics. Propositions about the consistency of the refined ABox w.r.t. the associated TBox when compa...