Spatio-Temporal Database Constraints for Spatial Dynamic SimulationBianca Maria PedrosaLuiz Camolesi JniorGilberto CmaraMarina Teresa Pires Vieira

UNIMEP

OutlineSpatial dynamic systemsTerraML computational environmentVariability in simulation processA land-use change application

Spatial dynamic systemsf ( I (tn )). . .FFf ( I (t) )f ( I (t+2) )Spatial dynamic systems simulates spatio-temporal processes in which the state of a location, on the Earths surface, changes over time, due to some physical phenomena.

Dynamic spatial models tp - 20 tp - 10tpfonte: Almeida et al (2003)

Spacial dynamic system elementsTransition RulesFuzzyL(Clue)Expander(Dinmica)LocalMean (Riks)ModelsdiscretehybridcontinuousDinmicaRiksClue

Spacial dynamic system elementsSpace representation

Neighborhood

modelo celularuniform proprieties regular structureproximitry matrixnon stationary

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TerraMLCell-based modeling languageTerraLib Modeling LanguageHybrid AutomataTemporal database constraintsNew

ConstraintsTransitions are processes representing evolution and therefore subject to constraints, which are preconditions to limit, avoid or force a changeVariability is a feature to establish the possibility and the change limits of objects Variability is associated to object attributes or processes to model the structural, functional and behavioral characteristics of elements in real world

Variability in simulation processInvariantDefined to attributes that cannot be changedAre used to represent immutable or stable characteristics

VariantDefined to attributes whose alterations are highly provable Support Evolution, involution or revolution of object or processes

Dimensioning the limitsMomentA time instant valueGranularityPrecision domain of time instant (ISO 2000)OrientationReference system (Gregorian calendar)DirectionAll orientation has a origin moment and everything happens after or before this moment (UTC)ApplicationThe use of temporal representation, allowing the semantic recognition of the time datatype

Expressing Variability conditions

TerraML Schema

TerraML Schema

TerraML Schema

A land use change applicattion

A land use change applicattionGLOBALLOCALDemand > 0Potential >0Global mode (for all cells)Calculate/update the Demand in each time stepCalculate/update the Global Demand in each time step

Local mode (for each cell)Calculate the cells potencial for changeSelect/alocate cells to change, based on demand

Local mode equations

TerraML script

TerraML script

TerraML script

Simulation result samples

ConclusionThe constraints model proposed is based on semantic representation of variability to transitions in simulations.The model proposed support both variant and invariant conditions and seems to cover the most frequent situations in environment systems. Future efforts will focus on extending constraints to support the orientation and direction aspects of time representation