The Small World of Pheromone Trails

  • Paola Pellegrini
  • Andrea Ellero
Part of the Lecture Notes in Computer Science book series (LNCS, volume 5217)


In this paper we consider \(\cal M\!AX\!\)\(\cal MI\!N\!\) Ant System and Ant Colony System. They are generally recognized to be the best performing algorithms of the Ant Colony Optimization family. They are characterized by a quite different way for dealing with the pheromone trail. We propose an experimental analysis for observing whether this difference impacts significantly on the characteristics of the pheromone distributions produced during the runs. The results obtained are analyzed by using some concepts derived by the literature on small-world networks. It comes out that ants actually build small-world pheromone graphs during their runs. This behavior is interpreted here as a sort of decomposition of the instances tackled.


Travel Salesman Problem Small World Pheromone Trail Objective Function Evaluation Characteristic Path Length 
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Copyright information

© Springer-Verlag Berlin Heidelberg 2008

Authors and Affiliations

  • Paola Pellegrini
    • 1
  • Andrea Ellero
    • 1
  1. 1.Department of Applied MathematicsUniversity Ca’ Foscari of VeniceVeniceItaly

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