A Composable Discrete-Time Cellular Automaton Formalism

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A Composable Discrete-TimeCellular Automaton
Formalism

• Gary R. Mayer Hessam S. Sarjoughian
• Gary.Mayer_at_asu.edu Sarjoughian_at_asu.edu
• Arizona Center for Integrative Modeling
  Simulation
• SBP 08
• 01 April 2008
• Phoenix, Arizona

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Rationale

• Cellular Automata has a central role in
  simulating many physical systems such as
  landscape processes
• Interesting complex systems can be best described
  using CA and other kinds of models
• Example sustainable socio-ecological
  organizations

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CA Approaches

• CA is intuitive for representing processes that
  can be cast into uniform structure with varied
  behavior e.g., land surface erosion
• CA is used to represent non-cellular abstractions
  e.g., restrictive for agent decision making
• CA is often combined with other models using
  arbitrary data and control schemes
  e.g., programming languages
• Existing CA formalisms treat CA as a grey box
• Initialize and peek at current state

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Composable CA

• Composable CA extends the CA formalism to
  formally represent non-cellular model
  interactions
• Benefits
• Avoid ambiguous composition of CAs with other
  models through formal description of I/O
  relationships
• Improve hybrid modeling for CA models
• Support detailed representations of agent and
  landscape process interactions
• Simplify model verification and simulation
  validation
• Model interaction visibility

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Composable CA Specification

• Represented as a network, N, of cells (individual
  automata)
• N ? XN , YN , D, Mijk, T, F ?, where
• Mijk ? Xijk , Yijk , Qijk , Iijk , ?ijk , ?ijk
  , T ?
• F fin , fout
• Difference between multi-dimensional CA and two
  composed CCAs is in the mapping

Distinguishes between internal and external I/O
Specific mapping functions between cells and
network as an entity