Search results for "Transient"

The severity of steatosis influences liver stiffness measurement in patients with nonalcoholic fatty liver disease

2015

In nonalcoholic fatty liver disease, the influence of severity of steatosis on liver stiffness measurement (LSM) is poorly studied and still debated. We assessed the impact of steatosis severity and its ultrasonographic (US) sign, severe bright liver echo pattern, on LSM values and on transient elastography accuracy for the diagnosis of liver fibrosis in a cohort of consecutive patients with nonalcoholic fatty liver disease. Patients (n = 253) were assessed by clinical, US, and histological (Kleiner score) features. Transient elastography was performed using the M probe. Among patients with low amounts of fibrosis (F0-F1 and F0-F2), median LSM values, expressed in kilopascals, were signific…

Differential diagnosis of vascular necrosis of the femoral head (AVN) and transient hip osteoporosis (THO): role of MRI

2014

A nonstationary model for the analysis of transient speech signals

1987

In this correspondence, a model is presented for the analysis of transient speech signals, which is based on a sum of the impulsive responses corresponding to a number of poles with time-dependent parameters. The aim of this analysis is to obtain discriminative features of the different transient elements of speech.

Chemosensory Receptors in the Larval Maxilla of Papilio hospiton

2022

Among the butterflies of the genus Papilio (Lepidoptera: Papilionidae), Papilio hospiton (Géné) has a geographical distribution limited to the Mediterranean islands of Sardinia (Italy) and Corsica (France). This is mainly due to the host range that includes only a few plant species of Apiaceae and Rutaceae growing on these islands. In a previous electrophysiological investigation conducted on the maxillary gustatory system of larvae of P. hospiton and its closely phylogenetically related species Papilio machaon, a significantly higher spike activity was shown for the gustatory neurons of lateral and medial styloconic sensilla in P. hospiton when bitter compounds were tested. This effect was…

Signatures of noise-enhanced stability in metastable state

2005

The lifetime of a metastable state in the transient dynamics of an overdamped Brownian particle is analyzed, both in terms of the mean first passage time and by means of the mean growth rate coefficient. Both quantities feature non monotonic behaviors as a function of the noise intensity, and are independent signatures of the noise enhanced stability effect. They can therefore be alternatively used to evaluate and estimate the presence of this phenomenon, which characterizes metastability in nonlinear physical systems.

Calibration of optimal execution of financial transactions in the presence of transient market impact

2012

Trading large volumes of a financial asset in order driven markets requires the use of algorithmic execution dividing the volume in many transactions in order to minimize costs due to market impact. A proper design of an optimal execution strategy strongly depends on a careful modeling of market impact, i.e. how the price reacts to trades. In this paper we consider a recently introduced market impact model (Bouchaud et al., 2004), which has the property of describing both the volume and the temporal dependence of price change due to trading. We show how this model can be used to describe price impact also in aggregated trade time or in real time. We then solve analytically and calibrate wit…

Consistent device simulation model describing perovskite solar cells in steady-state, transient, and frequency domain

2019

​This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Applied Materials & Interfaces, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see https://pubs.acs.org/doi/10.1021/acsami.9b04991

Improving the speed estimation by load torque estimation in induction motor drives: an MRAS and NUIO approach

2021

This paper proposes the application of the NUIO inside a FOC induction motor drive for the simultaneous estimation of the load torque and the rotor speed. The idea is to estimate at first the speed with the current model in parallel with a reference model developed on the basis of the voltage model of the induction machine. Then, the estimated speed is given as input to a nonlinear unknown input observer (NUIO) to estimate the load torque. This estimation is then used to correct the previous estimation of the speed. Simulation and experimental results confirm the goodness of the method for an extended range of speed and different load torque, and they confirm the reduction of error in trans…

Numerical analysis of thermally induced optical nonlinearity in GaSe layered crystal

1996

A numerical approach to studying thermally induced optical nonlinearity in semiconductors is presented. A transient finite difference algorithm is applied to solve the thermal diffusion equation coupled with the nonlinear absorbance-transmittance of Au/GaSe/Au samples with an applied electric field. The presented analysis can deal with any arbitrary axisymmetric dependence of the input power over the sample and external electric field, and provides information about the steady state and transitory effects in the transmittance.

Contaminant Intrusion through Leaks in Water Distribution System: Experimental Analysis

2015

Abstract This paper presents the results of experimental tests on the intrusion of contaminant through pipe cracks in water distribution network resulting from low/negative pressures. The tests were carried out on a looped distribution network at the University of Enna and were performed first producing a pressure transient that causes negative pressures then reproducing intermittent supply. A soluble contaminant was added to the water volume in the network through a pipe crack. Sampling of water volume was carried out in two nodes of the network and the contaminant concentrations were measured. It was showed that: the contaminant was drawn in and transported, in the first set of tests; the…