Search results for "modeling"

A novel approach to quantifying the sensitivity of current and future cosmological datasets to the neutrino mass ordering through Bayesian hierarchic…

2017

We present a novel approach to derive constraints on neutrino masses from cosmological data, while taking into account our ignorance of the neutrino mass ordering. We derive constraints from a combination of current and future cosmological datasets on the total neutrino mass $M_\nu$ and on the mass fractions carried by each of the mass eigenstates, after marginalizing over the (unknown) neutrino mass ordering, either normal (NH) or inverted (IH). The bounds take therefore into account the uncertainty related to our ignorance of the mass hierarchy. This novel approach is carried out in the framework of Bayesian analysis of a typical hierarchical problem. In this context, the choice of the ne…

Testing the stage-discharge relationship of a sharp crested sluice gate deduced by the momentum equation for a free-flow condition

2018

Abstract In this paper the stage-discharge relationship of a sharp crested sluice gate is deduced by applying the momentum equation for a free flow condition. The theoretically deduced stage-discharge formula was then calibrated using experimental flume data obtained in previous investigations carried out for a free-flow condition. The deduced stage–discharge relationship is characterized by a momentum coefficient which is empirically estimated by the ratio between the height of the orifice and the water depth in the section upstream the gate. The relative errors are always less than or equal to - 10% to +10% and 71.4% of the errors are less than or equal to ± 2%.

Modelling uncertainties in phase-space boundary integral models of ray propagation

2020

Abstract A recently proposed phase-space boundary integral model for the stochastic propagation of ray densities is presented and, for the first time, explicit connections between this model and parametric uncertainties arising in the underlying physical model are derived. In particular, an asymptotic analysis for a weak noise perturbation of the propagation speed is used to derive expressions for the probability distribution of the phase-space boundary coordinates after transport along uncertain, and in general curved, ray trajectories. Furthermore, models are presented for incorporating geometric uncertainties in terms of both the location of an edge within a polygonal domain, as well as …

Design of a Close Power Loop Test Bench for Contra-Rotating Propellers

2020

The aim of the research is to develop an azimuthing contra-rotating propeller for commercial applications with a power of 2000 kW. The thruster system is designed especially to be installed on high speed crafts (HSCs) for passenger transport with a cruising speed of about 35–40 knots. The topic is very useful because the azimuth thruster solutions currently do not find commercial applications in naval units for passenger transport. The latter are heavy, not very efficient from a hydrodynamic point of view and suitable for maximum cruising speed of about 18–20 knots. The study is interesting because among the advantages that these solutions provide are the possibility of transmitting very hi…

Errata to “On the instability of an axially moving elastic plate” [Int. J. Solids Struct. 47 (2010) 91–99]

2010

Control of quantum systems

1999

We propose a new control method for systems whose evolution is described by Schrödinger's equation (quantum dynamics). The goal of the control is to induce modifications of observable quantities — with possible effects at mesoscopic or macroscopic levels — by modifying the potential at the microscopic level. We illustrate the feasibility of the approach on a harmonic oscillator system.

Finite-size tests of hyperscaling.

1985

The possible form of hyperscaling violations in finite-size scaling theory is discussed. The implications for recent tests in Monte Carlo simulations of the d = 3 Ising model are examined, and new results for the d = 5 Ising model are presented.

Monte Carlo Simulation of Harmonic Generation in GaAs structures operating under large-signal Conditions

2007

By using a multiparticles Monte Carlo technique, with a self-consistently coupled one-dimensional Poisson solver, we investigate the dependence of the nonlinear carrier dynamics in GaAs n+nn+ micro e submicro-structures operating under very intense sub-terahertz signals by: (i) the frequency and the intensity of the excitation signal and (ii) the length of the n region.

SEGR in SiO${}_2$–Si$_3$N$_4$ Stacks

2014

Abstract. This work presents experimental Single Event Gate Rupture (SEGR) data for Metal–Insulator–Semiconductor (MIS) devices, where the gate dielectrics are made of stacked SiO2–Si3N4 structures. A semi-empirical model for predicting the critical gate voltage in these structures under heavy-ion exposure is first proposed. Then interrelationship between SEGR cross- section and heavy-ion induced energy deposition probability in thin dielectric layers is discussed. Qualitative connection between the energy deposition in the dielectric and the SEGR is proposed. peerReviewed

Electrical analogous in viscoelasticity

2014

In this paper, electrical analogous models of fractional hereditary materials are introduced. Based on recent works by the authors, mechanical models of materials viscoelasticity behavior are firstly approached by using fractional mathematical operators. Viscoelastic models have elastic and viscous components which are obtained by combining springs and dashpots. Various arrangements of these elements can be used, and all of these viscoelastic models can be equivalently modeled as electrical circuits, where the spring and dashpot are analogous to the capacitance and resistance, respectively. The proposed models are validated by using modal analysis. Moreover, a comparison with numerical expe…