CONTRACTION
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(1) |
| ID | ◀ 677 ▶ |
| Object type | Methodology or model |
Quality of an adaptive nonlinear system that tends to forget its timely working conditions in an exponential way (J.J. SLOTINE, 2002, p. 19)
SLOTINE writes: “If such a system is submitted to a temporary perturbatio n it will go back to what it was just doing- at that given moment” He adds: “…at least for small perturbations, such robustness is in fact a necessary condition for any learning : a system whose responses would be fundamentally different at each trial would be incomprehensible” (Ibid)
Moreover:“…the contraction property is automatically maintained by any combination (parallel , serial or hierarchical ; and some types of feedbacks) or dynamical recombination of subsystems , when these are also contractant” (Ibid)
Generally, contraction is a stabilization, or even self-stabilization device in nonlinear systems.
See also
Le Chatelier (Principle of), Least action (Principle of), Regulation, Slaving Principle