Optimization Online


On Ants, Bacteria and Dynamic Environments

Vitorino Ramos (vitorino.ramos***at***alfa.ist.utl.pt)
Carlos Fernandes (cfernandes***at***laseeb.org)
Agostinho C. Rosa (acrosa***at***isr.ist.utl.pt)

Abstract: Wasps, bees, ants and termites all make effective use of their environment and resources by displaying collective “swarm” intelligence. Termite colonies - for instance - build nests with a complexity far beyond the comprehension of the individual termite, while ant colonies dynamically allocate labor to various vital tasks such as foraging or defense without any central decision-making ability. Recent research suggests that microbial life can be even richer: highly social, intricately networked, and teeming with interactions, as found in bacteria. What strikes from these observations is that both ant colonies and bacteria have similar natural mechanisms based on Stigmergy and Self-Organization in order to emerge coherent and sophisticated patterns of global behaviour. Keeping in mind the above characteristics we will present a simple model to tackle the collective adaptation of a social swarm based on real ant colony behaviors (SSA algorithm) for tracking extrema in dynamic environments and highly multimodal complex functions described in the well-know De Jong test suite. Then, for the purpose of comparison, a recent model of artificial bacterial foraging (BFOA algorithm) based on similar stigmergic features is described and analyzed. Final results indicate that the SSA collective intelligence is able to cope and quickly adapt to unforeseen situations even when over the same cooperative foraging period, the community is requested to deal with two different and contradictory purposes, while outperforming BFOA in adaptive speed.

Keywords: Swarm Intelligence and Perception, Social Cognitive Maps, Social Foraging, Self-Organization, Distributed Search and Optimization in Dynamic Environments.

Category 1: Global Optimization

Category 2: Combinatorial Optimization (Meta Heuristics )

Category 3: Robust Optimization

Citation: in NCA-05, Natural Computing and Applications Workshop, IEEE Computer Press, Timisoara, Romania, Sep. 25-29, 2005.

Download: [PDF]

Entry Submitted: 12/02/2005
Entry Accepted: 12/02/2005
Entry Last Modified: 12/02/2005

Modify/Update this entry

  Visitors Authors More about us Links
  Subscribe, Unsubscribe
Digest Archive
Search, Browse the Repository


Coordinator's Board
Classification Scheme
Give us feedback
Optimization Journals, Sites, Societies
Mathematical Programming Society