Research
MTSA Presentations
Complex Systems Analysis using Space-Time Information Systems and Model Transition Sensitivity Analysis
G. M. Jacquez, presented at the Joint meeting of TIES 2004: The International Environmetrics Society and ACCURACY 2004: 6th International Symposium on Spatial Accuracy Assessment, June 28 – July 1 2004, Portland Maine
Real-world systems are dynamic, complex and geographic, yet many modeling tools for analyzing complex systems are not spatial, and GIS do to adequately represent time. This presentation describes two new approaches: Space-Time Information Systems (STIS), and Model Transition Sensitivity Analysis (MTSA).
Current GIS are based on spatial data models (the “what, when” diad) that inadequately characterize the “what, where, when” triad” needed for effective representation of complex systems. Purely spatial GIS cannot deal readily with space-time georeferencing nor space-time queries, and instead are best suited to “snapshots” of static systems. These deficiencies prompted many geographers to call for a “higher-dimensional GIS” (a STIS) to better represent space-time dynamics. When formulating models of complex systems, critical choices are made regarding model type and complexity. Model type is the mathematical approach employed, for example, a deterministic model versus a stochastic model. Model complexity is determined by the amount of abstraction and simplification employed during model construction. A growing body of work demonstrates that choice of model type and complexity has substantial impacts on simulation results and on model-based decisions. This presentation describes STIS and MTSA approaches that allow researchers to transit seamlessly from a deterministic model, to its stochastic counterpart, and on to its individual event history representation.