The paper shows how to give a direct discrete formulation of the wave equation starting directly from physical laws, i.e. without passing through differential formulation. Using global variables instead of scalar and vector field functions, a close link between global variables and spatial and temporal elements immediately appears. A preliminary classification of physical variables into three c...

BACKGROUND Heart failure prediction after acute myocardial infarction may have important clinical implications. OBJECTIVE To analyze the functional echocardiographic variables associated with heart failure in an infarction model in rats. METHODS The animals were divided into two groups: control and infarction. Subsequently, the infarcted animals were divided into groups: with and without he...

Introduction: Many patients have only diastolic dysfunction without any abnormality in systolic function. We compared cardiac diastolic parameters obtained by gated myocardial perfusion SPECT (Gated SPECT) with those evaluated by echocardiography. Methods: Forty-nine patients (aged 37-85 years, 19 males and 30 women) underwent Gated SPECT and echocardiogr...

The contact interface variables are difficult to measure for an ultrasonic motor. When the motor works under different preloads, error between traditional efficiency model and real output is quite large. In order solve these two problems, we propose a novel model. It takes measured preload feedback voltage data as input, which may offer better accuracy on-line ability. Firstly, effect of on dri...

In order to correctly predict and evaluate the response of wave energy converters (WECs), an accurate representation of wave climate resource is crucial. This paper gives an overview of wave resource modeling techniques and applies a methodology to estimate the naturally available and technically recoverable resource in a given deployment site. The methodology was initially developed by the Ele...

Propagation of torsional Alfvén waves along magnetic flux tubes has been extensively studied for many years but no conclusive results regarding the existence of a cutoff frequency for these waves have been obtained. The main purpose of this paper is to derive new wave equations that describe the propagation of linear torsional Alfvén waves along thin and isothermal magnetic flux tubes, and use ...