Abstract : the aim of this paper is to observe the group dynamic of funds’ managers during an interesting period : January 99July 01, which includes many financial events as financial cracks, high speculation on new technologies. We define a strategy as the sensitivity on French stock market indexes. We project strategies on a Kohonen Map. We propose a new approach to analyze the group dynamic ...

Self-organizing feature maps with self-determined local neighborhood widths are applied to construct principal manifolds of data distributions. This task exempli es the problem of the learning of learning parameters in neural networks. The proposed algorithm is based upon analytical results on phase transitions in self-organizing feature maps available for idealized situations. By illustrative ...

Abstract This paper describes recent efforts to model the remarkable ability of humans to recognize speech and words. Different techniques for representing phonological similarity between words in the lexicon with self-organizing algorithms are discussed. Simulations using the Standard Kohonen algorithm are presented to illustrate some problems confronted with this technique in modeling similar...

• Corresponding Author. • This research is support in part by a grant from the Dean’s Award for Excellence Summer Research Grants program at Arizona State University, College of Business. Abstract Kohonen's self-organizing map (SOM) network is one of the most important network architectures developed during the 1980's. The main function of SOM networks is to map the input data from an n-dimensi...

It is often reported in the technique literature that the success of the self-organizing feature map (SOM) formation is critically dependent on the initial weights and the selection of main parameters of the algorithm, namely, the learning-rate parameter and the neighborhood set. In this paper, we propose a healing mechanism to repair feature maps that are not well topologically ordered. The he...

Given a self–dual map on the sphere, the collection of its self– dual permutations generates a transformation group in which the map automorphism group appears as a subgroup of index two. A careful examination of this pairing yields direct constructions of self–dual maps and provides a classification of self–dual maps.