The most common way to define instantaneous amplitude, phase and frequency of a real signal is to use its analytic signal. One of the main advantages of this procedure is that it establishes a one-to-one relationship between any real signal and the pair of functions defining its instantaneous amplitude and phase. However, there are some problems in its physical interpretation but it is shown th...

We previously demonstrated that diuretic-induced hypovolemia resulted in an enhanced baroreflex-mediated increase in integrated muscle sympathetic nerve activity (MSNA) and vasomotor tone during lower body negative pressure (LBNP) (Am J Physiol Heart Circ Physiol 282: H645-H655, 2002). The purpose of this study was to perform a retrospective analysis of these data and examine the ability of rel...

Certain visual stimuli, such as striped patterns and filtered noise, have been reported to be uncomfortable. Some filtered noise patterns judged as uncomfortable are those with a relative decrease in contrast amplitude at high spatial frequencies, compared with the statistics typical of natural images. Decreased amplitude at high spatial frequencies is a characteristic often associated with per...

BACKGROUND Human muscle sympathetic nerve activity (MSNA) is usually measured as the number of pulse-synchronous bursts in multiunit mean voltage recordings. We recently suggested burst amplitude distribution as a more sensitive indicator of altered MSNA in congestive heart failure (CHF). Here, we test whether this distribution can discriminate between different conditions with increased MSNA b...

The present work deals with those properties of the human motor system that characterize cyclic movements of maximum (expected to be maximum) intensity. It presents the results of an experiment carried out on 11 subjects and aimed at measuring the kinematic characteristics of cyclic movements of the elbow joint executed at maximal frequency under unloaded conditions. The movements of five ampli...

Intrinsic coupling of neuronal assemblies constitutes a key feature of ongoing brain activity, yielding the rich spatiotemporal patterns observed in neuroimaging data and putatively supporting cognitive processes. Intrinsic coupling has been investigated in electrophysiological recordings using two types of functional connectivity measures: amplitude and phase coupling. These two coupling modes...

In this note, small amplitude free vibration of a double-beam system in presence of inner layer nonlinearity is investigated. The nonlinearity is due to inner layer material and is not related to large amplitude vibration. At first, frequencies of a double-beam system with linear inner layer are studied and categorized as synchronous and asynchronous frequencies. It is revealed that the inner l...

free surface sloshing of liquid in a rectangular tank induced by lateral excitation has been studied numericallyand experimentally in this paper. the numerical simulation is carried out based on the volume of fluid (vof) method that provides free surface extraction in such problem. a tank with transparent walls is used to free surface tracking in experimental study while the movement amplitude ...

In the present paper, the problem of reflection and transmission of waves at an interface of elastic and microstretch thermoelastic solids with microtemperatureshas been studied. The amplitude ratios of various reflected and transmitted waves are functions of angle of incidence and frequency of incident wave. The expressions of amplitude ratios have been computed numerically for a particular mo...