Recent studies of decadal/interdecadal climate variability suggested two main classes of mechanisms: selfsustained (supercritical) oscillations due to the internal nonlinearity of the ocean and linear (subcritical) thermohaline oscillations driven by stochastic atmospheric forcing. The authors use a coupled ocean–atmosphere meridional box model to carefully examine these two alternatives. It is...

In this paper, Wavelet Collocation Method has been used to solve nonlinear fin problem with temperature dependent thermal conductivity and heat transfer coefficient. Thermal conductivity of fin materials varies any type so that we consider thermal conductivity as the general function of temperature.  Here we consider three particular cases, where we assume that thermal conductivity is constant,...

To explain time-scale invariant distributions of response latencies, it appears to be necessary to postulate scalar noise in the remembered intervals, against which the subjective measure of the currently elapsing interval is compared. At least in some cases, the observed variability cannot be due to variability in the subjective intervals written to memory; it must come from noise (variability...

Cardiac variability can be assessed from two perspectives: beat-to-beat performance and continuous performance during the cardiac cycle. Linear analysis techniques assess cardiac variability by measuring the physical attributes of a signal, whereas nonlinear techniques evaluate signal dynamics. This study sought to determine if recurrence quantification analysis (RQA), a nonlinear technique, co...

In this note, we develop semi-analytical techniques to obtain the full correlational structure of a stochastic network of nonlinear neurons described by rate variables. Under the assumption that pairs of membrane potentials are jointly Gaussian – which they tend to be in large networks – we obtain deterministic equations for the temporal evolution of the mean firing rates and the noise covarian...

We suggest a new nonlinear expansion of space-distributed observational time series. The expansion allows constructing principal nonlinear manifolds holding essential part of observed variability. It yields low-dimensional hidden time series interpreted as internal modes driving observed multivariate dynamics as well as their mapping to a geographic grid. Bayesian optimality is used for selecti...

The approach to the problem of voice variability solving based on nonlinear VolterraWiener filtering is proposed.

A central and classic question in ecology is what causes populations to fluctuate in abundance. Understanding the interaction between natural drivers of fluctuating populations and human exploitation is an issue of paramount importance for conservation and natural resource management. Three main hypotheses have been proposed to explain fluctuations: (i) species interactions, such as predator-pr...

The objectives of this review are to discuss the diversity of mechanisms that may explain the association between heart rate (HR) variability and mortality, to appraise the clinical applicability of traditional and new measures of HR variability and to propose future directions in this field of research. There is a large body of data demonstrating that abnormal HR variability measured over a 24...

BACKGROUND AND PURPOSE Greater gait variability has been observed in persons with Down syndrome (DS). An understanding of baseline patterns of variability, how these patterns relate to adaptive control of gait, and whether increasing or decreasing variability is better is necessary for physical therapists to determine whether and when to intervene. Our aim was to describe patterns of gait varia...