Supervised Contractive Neural Network
This ANNs calculates two net inputs for each node: a classic weighted input and a contractive input. This second net input tends to decay or to increase when the positive or negative value of the weight (w) becomes close to a specific constant (C). The contractive input works as a harmonic modulation of the weighted input.
 P.M. Buscema, G. Massini, G. Maurelli
Artificial Adaptive Systems to predict the magnitude of earthquakes
Bollettino di Geofisica Teorica ed Applicata Vol. 56, n. 2, pp. 227-256; June 2015.
 P.M. Buscema, R. Benzi
Quakes Prediction Using Highly Non Linear Systems and A Minimal Dataset
Chapter 4, pp 41-66, in P.M.Buscema & M.Ruggieri (eds), Advanced Networks, Algorithms and Modeling for Earthquake Prediction, River Publishers, 2011.