# Dictionary Definition

intermittency n : the quality of being
intermittent; subject to interruption or periodic stopping [syn:
intermittence]

# User Contributed Dictionary

# Extensive Definition

In dynamical
systems, intermittency is the alternation of phases of
apparently periodic and chaotic
dynamics.

Consider a dynamical system. Let x be the
observed variable. If x plotted as a function of time exhibits
segments of relative constant values (laminar
phase) interspersed by erratic bursts, the system dynamics is
intermittent.http://www.ccs.fau.edu/~ding/Intermittency.pdf

In the apparently periodic phases the behaviour
is not quite, but only nearly periodic. Thus, rather than a (truly
periodic) series of values such as 2, 4, 2, 4, ... one might have
something like 2.0001, 4.0003, 2.0002, 4.0001, 2.0003, 3.9999,
1.8715, 6.7486, ... where the first six values are apparently
periodic but where the actually chaotic nature of the system
becomes apparent after the value 3.9999 is reached.

Intermittency factor is the fraction of time that
motion is turbulent,
denoted \mu.