How to improve the convergence on sigmoid Fuzzy Cognitive Maps?

Gonzalo Nápoles*, Rafael Bello, Koen Vanhoof

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

Abstract

Fuzzy Cognitive Maps (FCM) may be defined as Recurrent Neural Networks that allow causal reasoning. According to the transformation function used for updating the activation value of concepts they can be characterized as discrete or continuous. It is remarkable that FCM having discrete neurons never exhibit chaotic states, but this premise cannot be guaranteed for FCM having continuous concepts. On the other hand, complex Sigmoid FCM resulting from experts or learning algorithms often show chaotic or cyclic patterns, therefore leading to confusing interpretation of the investigated system. The first contribution of this paper is focused on explaining why most studies on FCM stability are not applicable to FCM used on classification or decision-making tasks. Next we describe a non-direct learning methodology based on Swarm Intelligence for improving the system stability once the causal weight estimation is done. The objective here is to find a specific threshold function for each map neuron simulating an external stimulus, instead of using the same transformation function for all concepts. At the end, we can compute more stable maps, so better consistency in hidden patterns is achieved.
Original languageEnglish
Pages (from-to)S77-S88
JournalIntelligent Data Analysis
Volume18
DOIs
Publication statusPublished - 2014
Externally publishedYes

Keywords

  • Fuzzy Cognitive Maps
  • stability
  • prediction
  • learning algorithm

Fingerprint

Dive into the research topics of 'How to improve the convergence on sigmoid Fuzzy Cognitive Maps?'. Together they form a unique fingerprint.

Cite this