Search results for "Pulse"

Facilitadores en el procesamiento cognitivo de la información rítmica

2021

Rhythm perception models have studied an important variety of general characteristics of temporal structures and specific elements of musical rhythm, presenting a degree of heterogeneity in study objects. However, most of the research converges in the study of processes related to the listener's detection of an underlying temporal pulse. This, along with other processes such as temporal grouping, have been referred to as basic or primitive aspects, since they seem fundamental to the perception of simple rhythmic sequences. In the present work, a review of the literature in which research findings related to the cognitive processing of basic rhythmic aspects are described, synthesized and re…

Practical Implementation of a Synchronous PWM Strategy for Low Switching Frequency FOC of im Drives with ATSAM3X8E Microcontroller

2021

This paper presents a practical implementation of synchronous PWM modulation algorithm for an induction motor field oriented control powered by a DC/AC inverter and implemented on a low-cost microcontroller, the ATSAM3X8E. In particular, a simple algorithm, capable to calculate automatically an optimized set of frequency modulation indexes will be presented. Hysteresis bands are also introduced in the algorithm in order to avoid multiple changeovers during modulation index transitions. Experimental tests and their results will be shown and discussed, highlighting the benefits of the present algorithm, such as reduction of current harmonic content, reduction of current ripple and, consequent…

Ventricular-vascular coupling in hypertension: methodological considerations and clinical implications.

2014

The present review is addressed to analyse the complex interplay between left ventricle and arterial tree in hypertension. The different methodological approaches to the analysis of ventricular vascular coupling in the time and frequency domain are discussed. Moreover, the role of hypertension-related changes of arterial structure and function (stiffness and wave reflection) on arterial load and how ventricular-vascular coupling modulates the process of left ventricular adaptation to hypertension are analysed.The different interplay between vascular bed and left ventricle emerges as the pathophysiological basis for the development of the multiple patterns of ventricular structural adaptatio…

Biophotonics in veterinary medicine: the first steps toward clinical translation

2019

In this paper, we analyzed the current situation and the potential of biophotonics and biomedical optics in veterinary medicine. Promising optical techniques such as optical coherence tomography, pulse oximeter, and hyperspectral imaging have been clinically translated into human medicine. But even though human and small animal medicine share personalized and state-of-the-art approach, biophotonics remains rarely exploited in the canine and feline medicine. However, there are some biophotonics studies in veterinary oncology which addressed tumor diagnosis (skin and subcutaneous tumors), prognosis (lymphoma), and therapy (clear surgical margins). Visible and near-infrared spectroscopy served…

Suppression of extinction with TMS in humans: from healthy controls to patients.

2006

We review a series of studies exemplifying some applications of single-pulse and paired-transcranial magnetic stimulation (TMS) in the study of spatial attention and of its deficits. We will focus primarily on sensory extinction, the failure to consciously perceive a contralesional sensory stimulus only during bilateral stimulation of homologous surfaces. TMS studies in healthy controls show that it is possible either to interfere or modulate the excitability of the parietal cortex during sensory (i.e. tactile and visual) attentional tasks, thus reproducing a condition of virtual extinction. TMS studies in patients with unilateral (mainly right) brain damage show that the modulation of the …

Universal charts for optical difference frequency generation in the terahertz domain

2010

We present a universal and rigorous approach to study difference frequency generation in the terahertz domain, keeping the number of degrees of freedom to a minimum, through the definition of a suitable figure of merit. The proposed method relies on suitably normalized charts, that enable to predict the optical-to-terahertz conversion efficiency of any system based on wave propagation in quadratic nonlinear materials. The predictions of our approach are found to be in good agreement with the best experimental results reported to date, enabling also to estimate the d22 nonlinear coefficient of high quality GaSe.

Combination of finite impulse response neural network technique with FDTD method for simulation of electromagnetic problems

1996

The finite difference time domain (FDTD) method requires long computation times for simulating resonant or high-Q structures. The authors incorporate the finite impulse response neural network technique as a predictor in order to save time in FDTD simulations. The applicability of the technique is demonstrated by carrying out an analysis of a waveguide filter.

FDTD signal extrapolation using a finite impulse response neural network model

1999

Modeling an X-ray Flare on Proxima Centauri: evidence of two flaring loop components and of two heating mechanisms at work

2003

We model in detail a flare observed on Proxima Centauri with the EPIC-PN on board XMM-Newton at high statistics and high time resolution and coverage. Time-dependent hydrodynamic loop modeling is used to describe the rise and peak of the light curve, and a large fraction of the decay, including its change of slope and a secondary maximum, over a duration of more than 2 hours. The light curve, the emission measure and the temperature derived from the data allow us to constrain the loop morphology and the heating function and to show that this flare can be described with two components: a major one triggered by an intense heat pulse injected in a single flaring loop with half-length ~1.0 10^{…

Inverse prediction of local interface temperature during electromagnetic pulse welding via precipitate kinetics

2019

Abstract Interface temperature of electromagnetic pulse welding is difficult to measure by insitu methods. Here, the local temperature rise is investigated using the kinetics of precipitates and dispersoids (transformation or dissolution) at the interface zone (IZ) and affected zone (AZ) of three welds. This fine scale analysis allows estimating of local temperature range for AZ that reaches between 250 and 360 °C on both sides of narrow IZ, while the IZ itself experiences between 360 and 500 °C or even beyond 500 °C. The interface temperature increases with the increasing impact intensity. The current work estimated thermal field based on the precipitate transformations, which occur during…