Sensory stimuli under natural conditions often consist of a temporally irregular sequence of events, contrasting with the periodic sequences commonly used as stimuli in the laboratory. These experiments compared the responses of neurons in rat barrel cortex with trains of whisker movements with different frequencies; each train possessed either a periodic or an irregular, "noisy" temporal struc...

Consider a dynamical system given by a planar differential equation, which exhibits an unstable periodic orbit surrounding a stable periodic orbit. It is known that under random perturbations, the distribution of locations where the system’s first exit from the interior of the unstable orbit occurs, typically displays the phenomenon of cycling: The distribution of first-exit locations is transl...

The harmful effect of the noise on human health has been known for many decades and it's first harmful effect on the hearing came to be known in the year 1831. According to the nature of the work, this di- sease was called Boiler Maker's deafness.  Noise due to the industrial machineries is one of the main cause of Environmental Poliution, and among the different industreis, Textile industry i...

SUMMARY This paper proposes a robust method for estimating the fundamental frequency (F0) in real environments. It is assumed that the spectral structure of real environmental noise varies momentarily and its energy does not distribute evenly in the time-frequency domain. Therefore, segmenting a spec-trogram of speech mixed with environmental noise into narrow time-frequency regions will produc...

The detection and estimation of machine vibration multiperiodic signals of unknown periods in white Gaussian noise is investigated. New estimates for the subsignals (signals making up the received signal) and their periods are derived using an orthogonal subspace decomposition approach. The concept of exactly periodic signals is introduced. This in turn simplifies and enhances the understanding...

| A numerical noise analysis method for oscillators is proposed. Noise sources are usually small and can be considered as perturbations to a large amplitude oscillation. Transfer functions from each noise source to the oscillator output can be calculated by modeling the oscillator as a linear periodic time-varying circuit. The proposed method is a time domain method and can be applied to strong...

Aiming at the feature extraction of weak periodic signal in early fault of machinery, a novel weak periodic signal detection with Duffing oscillator based on empirical mode decomposition (EMD) was presented. The chaotic character of Duffing oscillator was analyzed, and the Melnikov method of determining chaotic threshold of Duffing oscillators was discussed. The principle of weak signal detecti...

We address the detection of unstable periodic orbits from experimentally measured transient chaotic time series. In particular, we examine recurrence times of trajectories in the vector space reconstructed from an ensemble of such time series. Numerical experiments demonstrate that this strategy can yield periodic orbits of low periods even when noise is present. We analyze the probability of f...

We study an influence of white Gaussian noise on synchrony of neural oscillators. In neurophysiology, the property of a single neuron to provide identical outputs for repeated noisy input (in terms of our problem, an array of such identical neurons driven by common noise to behave synchronously) is referred as “reliability” [1]. The first quantifier of the synchrony we use is the Lyapunov expon...

We show that weak periodic driving can exponentially strongly change the rate of escape from a potential well of a system driven by telegraph noise. The analysis refers to an overdamped system, where escape requires that the noise amplitude θ exceed a critical value θ(c). For θ close to θ(c), the exponent of the escape rate displays a nonanalytic dependence on the amplitude of an additional low...