Computational Science Technical Note CSTN-113


Multiphase Updating - A Practical Approach to Simulating Animat Agents

C.J.Scogings and K.A.Hawick

Archived July 2011, Revised March 2012


A growing number of applications can be modelled using spatial agent systems or animats. Typical animat simulations model collective macroscopic phenomena using encoded individual behaviours for microscopic agents. In spatial agent systems there are well known problems occur if agent cells are updated in a sequential order. This is known as the sweeping problem and it occurs in other numerical simulations such as differential equation solvers too and leads to observable macroscopic effects in the simulated sytem that are solely artifacts of the implementation algorithm. We explore various strategies to remove these artifacts including multi-phase updating. We find that in some models that include non-diffusional effects such as predator-prey interactions, a two-phase update is not sufficient and a three-phase update strategy is necessary to preserve model semantics, particularly when concurrency is used to speed up the model. We discuss the computational implications of this for animat agent simulations.

Keywords: agent-based models; updating agents; multi-phase update; animats; model semantics.

Full Document Text: PDF version.

Citation Information: BiBTeX database for CSTN Notes.

BiBTeX reference:

  author = {C. J. Scogings and K. A. Hawick},
  title = {Multiphase Updating - A Practical Approach to Simulating Animat Agents},
  booktitle = {Proc. Int. Conf. on Artificial Intelligence (ICAI'12)},
  year = {2012},
  pages = {1-7},
  address = {Las Vegas, USA},
  month = {16-19 July},
  organization = {WorldComp},
  institution = {Computer Science, Massey University},
  timestamp = {2010.09.19}

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