A robust and flexible model of hierarchical self-organizing maps for non-stationary environments

  • Authors:
  • R. Salas;S. Moreno;H. Allende;C. Moraga

  • Affiliations:
  • Departamento de Ingeniería Biomédica, Universidad de Valparaíso, Av. Errázuriz 2190, Valparaíso, Chile and Dept. de Informática, Universidad Técnica Federico San ...;Dept. de Informática, Universidad Técnica Federico Santa María, Chile;Dept. de Informática, Universidad Técnica Federico Santa María, Chile;European Centre for Soft Computing, E-33600 Mieres, Spain and Department of Computer Science, University of Dortmund, Germany

  • Venue:
  • Neurocomputing
  • Year:
  • 2007

Quantified Score

Hi-index 0.01

Visualization

Abstract

In this paper we extend the hierarchical self-organizing maps model (HSOM) to address the problem of learning topological drift under non-stationary and noisy environments. The new model, called robust and flexible hierarchical self-organizing maps (RoFlex-HSOM), combines the capabilities of robustness against noise and the flexibility to adapt to the changing environment. The RoFlex-HSOM model consists of a hierarchical tree structure of growing self-organizing maps (SOMs) that adapts its architecture based on the data. The model preserves the topology mapping from the high-dimensional time-dependent input space onto a neuron position in a low-dimensional hierarchical output space grid. Furthermore, the RoFlex-HSOM algorithm has the plasticity to track and adapt to the topological drift, it gradually forgets (but no catastrophically) previous learned patterns and it is resistant to the presence of noise. We empirically show the capabilities of our model with experimental results using synthetic sequential data sets and the ''El Nino'' real world data.