A new unsupervised competitive learning rule is introduced, called the Self-organizing free-topology map (Softmap) algorithm, for nonparametric density estimation. The receptive fields of the formal neurons are overlapping, radially-symmetric kernels, the radii of which are adapted to the local input density together with the weight vectors which define the kernel centers. A fuzzy code membership function is introduced in order to encompass, in a novel way, the presence of overlapping receptive… CONTINUE READING
Figure 3. Density function Equation (16) (A), and nonparametric models obtained by allocating adaptive kernels at the weights shown in Figures 2B–E (B–E), and by using the variable kernel method (F). See text for details.