A basic requirement for on-off intermittency to occur is that the system possesses an invariant subspace. We address how on-off intermittency manifests itself when a perturbation destroys the invariant subspace. In particular, we distinguish between situations where the threshold for measuring the on-off intermittency in numerical or physical experiments is much larger than or is comparable to ...

We study experimentally the dynamics of granular media in a discharging hopper. In such flows, there often appears to be a critical outlet size D_{c} such that the flow never clogs for D>D_{c}. We report on the time-averaged velocity distributions, as well as temporal intermittency in the ensemble-averaged velocity of grains in a viewing window, for both DD_{c}, near and far from t...

The solar-terrestrial environment provides a natural laboratory for observing intermittent turbulence [1]. The degree of non-Gaussianity (intermittency) in a turbulence can be quantified by calculating the normalized fourth-order structure function, also known as kurtosis. Recently, a phase coherence surrogate technique for characterizing phase synchronization was developed for space plasmas [2...

Two datasets of turbulence velocities collected over different bedform types under contrasting experimental conditions show similarity in terms of velocity-intermittency characteristics and suggest a universality to the velocity-intermittency structure for flow over bedforms. One dataset was obtained by sampling flow over static bedforms in different locations, and the other was based on a stat...

This study proposes a novel framework based on magnitude cumulant and surrogate analyses to reliably detect the presence of intermittency and estimate the intermittency coefficient from short-length coarse-resolution turbulent time series. Intermittency coefficients estimated from a large number of neutrally stratified atmospheric surface layer turbulent series from various field campaigns are ...

Isotropic, rotating, and stratified turbulent flows are analyzed using a scale- and direction-dependent flatness. The anisotropy of the spatial fluctuations of the energy distribution can hereby be quantified for different length scales. This measure allows one to distinguish between longitudinal and transversal intermittency as well as between horizontal and vertical intermittency. The differe...

Force intermittency is one of the major causes of motor variability. Focusing on the dynamics of force intermittency, this study was undertaken to investigate how force trajectory is fine-tuned for static and dynamic force-tracking of a comparable physical load. Twenty-two healthy adults performed two unilateral resistance protocols (static force-tracking at 75% maximal effort and dynamic force...

We investigate the breaking of proper self similarity of attractors in the presence of intermittency. We show that this can lead to dramatically too small values of the numerically estimated correlation dimension D 2 , which we relate, in the case of type I intermittency, to universal scaling properties in the vicinity of the critical value of the control parameter. For spatially extended syste...