OSCILLATION
| Collection | International Encyclopedia of Systems and Cybernetics |
|---|---|
| Year | 2004 |
| Vol. (num.) | 2(2) |
| ID | ◀ 2434 ▶ |
| Object type | Methodology or model |
A more or less periodic change of the values of a function in a system.
Oscillations can be: regularly sinusoidal; of relaxation; periodic but complex (i.e. composed of various sinusoidal oscillations of different frequencies and amplitudes); mixed chaotic and periodic, or totally chaotic. (I. PRIGOGINE, 1984, p.55)
In dynamic equilibrium conditions, they are generally steady or progressively damped. Far- from- equilibrium, they become amplifying fluctuations and finally lead the system over an instability threshold. This in turn is conducive either to its destruction or to its emergence at a higher level of structural and functional complexity.
The homogeneous steady state could be considered as non-oscillatory.
Oscillations can be an effect of time lags.
This has been demonstrated long ago by VOLTERRA and LOTKA's study of the population's fluctuations.
More recently, it is a characteristic feature of J. FORRESTER's Systems Dynamics.
This is quite understandable, as the corrective action of any regulator is always late: its impact is felt on the controlled value when other variations already changed the value's level.
P. MANZELLI states (with reference to biochemical processes): “…oscillating reactions show an auto-organized action that needs the supposition that the interacting particles can ”communicate information“ among themselves to establish a global behavior of the space/time transformation of the reaction” (1993, p.334).
This process results generally of intricate sets of feedbacks, as in catalysis or hypercycles.