This paper recommends a simple and excusive approach to strongly nonlinear oscillator. Its frequency property can be immediately obtained by the simplest calculation. The results show that method leads an approximate solution with relatively high accuracy. Considering process, this provides highly efficient tool for fast determination of amplitude-frequency relationship large amplitude vibratio...

I always had difficulties in understanding frequency modulation (FM) and its frequency spectrum. Even for the pure tone modulation, the FM spectrum consists of an infinite number of sidebands whose signs change from one sideband to the next one and whose amplitudes are given by the horrible Bessel functions. . . I work for Zurich Instruments, a Swiss maker of lock-in amplifiers and it has becom...

A number of recent scientific and engineering problems require signals to be decomposed into a product of a slowly varying positive envelope and a quickly varying carrier whose instantaneous frequency also varies slowly over time. Although signal processing provides algorithms for so-called amplitudeand frequencydemodulation (AFD), there are well known problems with all of the existing methods....

The relationship between clinically scored tremor and electromyographic measurements of tremor amplitude is not clear and few reports have examined correlations between different tremor parameters. The aim of this study was to evaluate the correlations between different tremor parameters, clinical tremor scoring, age and disease duration. A total of 525 patients with different types of tremor w...

based on the convolutional model, a seismic trace is the convolution of seismic source wavelet and reflection coefficient series of the earth. seismic source wavelet estimation is one of the most important stages in processing and interpretation of seismic data. accurate estimation of wavelet increases the efficiency of the deconvolution and temporal resolution of seismic data. on the other han...

Wingbeat frequency (f(w)) and amplitude (theta;(w)) were measured for 23 species of Australian bat, representing two sub-orders and six families. Maximum values were between 4 and 13 Hz for f(w), and between 90 and 150 degrees for theta;(w), depending on the species. Wingbeat frequency for each species was found to vary only slightly with flight speed over the lower half of the speed range. At ...

In many applications the flow that past bluff bodies has frequency nature (oscillated) and it is not uniform. This kind of flow has effects on the formation of vortex shedding behind bluff bodies. In this paper the flow around a circular cylinder was numerically simulated. The effects of frequency variation at inlet flow on the vortex shedding frequency were investigated. The transient Two-Dime...

Major proportion of intracellular calcium (Ca 2+ ) is achieved through opening of calcium channels present in the plasma membrane which play an important role in regulating neuromuscular coordination and release of neurotransmitters from nerve terminals. Blockade of these calcium channels adversely affect contractile process and release of neurotransmitters in majority of the neuromuscular prep...

Surface mechanomyographic (MMG) signals have been detected during various types of dynamic muscle actions, including dynamic constant external resistance (DCER) muscle actions, concentric and eccentric isokinetic muscle actions, as well as incremental and constant power output cycle ergometry. Although the MMG amplitude and center frequency [mean power frequency (MPF) or median frequency] respo...

Recent studies of brain activities show that cross-frequency coupling (CFC) play an important role in memory and learning. Many measures have been proposed to investigate the CFC phenomenon, including the correlation between the amplitude envelopes of two brain waves at different frequencies - cross-frequency amplitude-amplitude coupling (AAC). In this short communication, we describe how nonst...