The spatio-temporal topological operator dimension, a hyperstructure for multidimensional spatio-temporal exploration and analysis
Y. Bédard, Pierre Marchand · 2004
Building and running Spatio-Temporal Exploration and Analysis (STEA) queries for today's flavors of databases and Geographic Information Systems (GISs) is a difficult task. The iterative navigation from general views (coarse granularity) to very detailed views (fine granularity) according to multiple themes implies running large queries against large volumes of data in reasonable time. In some cases, users lose their “train-of-thought” due the long query run times. In others, users lose their “ train-of-thought” due to the complexity of the query language. In order to interface effectively with human cognitive systems, systems aimed at supporting STEA must comply with principles of human spatial cognition. Among these principles, hierarchies, topology, the coupling of geographic space and time and short query run times are essential. The goal of this thesis is propose a new data structure, the Spatio-Temporal Topological Operator Dimension (STTOD), which implements a hierarchy of spatio-temporal topological operators in a multidimensional database (MDDB) to support STEA. This hierarchy covers the three possible domains of spatio-temporal topological constraints e.g. spatial, temporal and spatio-temporal. Operators at the highest level carry general meanings while operators from the lowest levels have very specific meanings. This hierarchy is structured according to multiple levels of granularity based on cognitive models, generalized relationships and formal models of topological relationships. The topological relationships are described either through groups of operators or through the ISO/TC 211 9-intersection method (9IM) developed by Egenhofer and Herring (1994) and the DE + 9IM developed by Clementini and Di Felice (1994). This research followed an experimental type of research to implement and to test the validity of the STTOD in the context of Automatic Position Reporting System (APRS), the amateur radio system for position report transmission. We demonstrated that the implementation of the STTOD allows adequate STEA by permitting spatio-temporal topological analysis within the multidimensional approach. We also demonstrated that such an implementation offers query run times which permit to maintain a “train-of-thought” during as they are compatible with Newell's (1990) cognitive band. This proposed solution represents a new approach for rapid and intuitive STEA while being generic, software-independent and implementable in today's commercial MDDBs.