Publications associées à Existence and orbital stability of standing waves for some nonlinear Schrodinger equations, perturbation of a model case

Stochastic particle transport by deep-water irregular breaking waves

Correct prediction of particle transport by surface waves is crucial in many practical applications such as search and rescue or salvage operations and pollution tracking and clean-up efforts. Recent results by Deike et al. (J. Fluid Mech., vol. 829, 2017, ...

Cambridge University Press2023

Self-sustained dynamics and forced resonant oscillations in flows: cross-junction jets and sloshing liquids

Alessandro Bongarzone

In engineering, oscillatory instabilities and resonances are often considered undesirable flow features and measures are taken to avoid them. This may include avoiding certain parametric regions or implementing control and mitigation strategies. However, t ...

EPFL2023

Numerical and experimental investigation of spiral-grooved gas journal bearings

Elia Iseli

Small-scale turbomachinery is increasingly used in carbon-free energy conversion systems, such as commercial or domestic scale heat pumps, fuels cells for transportation and waste heat recovery. The usage of aerodynamic bearings allows the design of compac ...

EPFL2022

Nonlinear Inverse Problems in Quantitative Phase Imaging

Thanh-An Michel Pham

The topic of this thesis is the development of new algorithmic reconstruction methods for quantitative phase imaging (QPI). In the past decade, advanced QPI has emerged as a valuable tool to study label-free biological samples and uncover their 3D structur ...

EPFL2022

Charge-based modeling of ultra narrow junctionless cylindrical nanowire FETs

Farzan Jazaeri

This brief proposes an analytical approach to model the DC electrical behavior of extremely narrow cylindrical junctionless nanowire field-effect transistors (JL-NW-FETs). The model includes explicit expressions, taking into account the first-order perturb ...

PERGAMON-ELSEVIER SCIENCE LTD2021

Measurement and Modeling of Both Distant and Close Electric Fields of an M‐Component in Rocket‐Triggered Lightning

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Mi Zhou, Amirhossein Mostajabi, Qi Li

Simultaneous measurements of current and multiple‐station electric fields associated with a 5.4‐kA‐peak M‐component in rocket‐triggered lightning are presented in this study. A close‐range electric field measurement site was located northeast of the trigge ...

2020

Nonreciprocity in Uniform Time-Varying Materials Using Spatial Dispersion

Xiaoqiang Wang, Mohammad Sajjad Mirmoosa, Xiao Wang

Conventionally, nonreciprocity in time-varying systems is achieved by exploiting both temporal and spatial modulations. In this paper, we introduce a concept of magnetless bianisotropic time-modulated systems that support nonreciprocal wave propagation at ...

IEEE2020

Stability of standing waves for a nonlinear Klein-Gordon equation with delta potentials

François Samer Genoud

In this paper, we study local well-posedness and orbital stability of standing waves for a singularly perturbed one-dimensional nonlinear Klein-Gordon equation. We first establish local well-posedness of the Cauchy problem by a fixed point argument. Unlike ...

2019

Coupled-mode theory for stationary and nonstationary resonant sound propagation

Romain Christophe Rémy Fleury, Theodoros Koutserimpas

In this paper, we present a complete analytical derivation of the equations used for stationary and nonstationary wave systems regarding resonant sound transmission and reflection described by the phenomenological coupled-mode theory. We calculate the prop ...

2019

Dynamical Reduced Basis Methods for Hamiltonian Systems

Cecilia Pagliantini

We consider model order reduction of parameterized Hamiltonian systems describing nondissipative phenomena, like wave-type and transport dominated problems. The development of reduced basis methods for such models is challenged by two main factors: the ric ...

Springer2021

Turbulent patterns in wall-bounded shear flows: invariant solutions and their bifurcations

Florian Reetz

When laminar shear flows in large wall-bounded domains transition to turbulence, the flow exhibits spatio-temporally chaotic dynamics. Despite its chaotic dynamics, the flow may self-organize into characteristic spatially periodic patterns of unknown origi ...

EPFL2019

Deep Convolutional Neural Network for Ultrasound Image Enhancement

Adrien Besson, Jean-Philippe Thiran, Dimitris Perdios, Adrien Georges Jean Besson, Florian Martinez, Marcel Arditi, Manuel Vonlanthen

The problem of improving image quality in ultrafast ultrasound (US) imaging by means of regularized iterative algorithms has raised a vast interest in the US community. These approaches usually rely on standard image processing priors, such as wavelet spar ...

IEEE2018

Libraries of Extremely Localized Molecular Orbitals. 3. Construction and Preliminary Assessment of the New Databanks

Benjamin André René Meyer

The fast and reliable determination of wave functions and electron densities of macromolecules has been one of the goals of theoretical chemistry for a long time, and in this context, several linear scaling techniques have been successfully devised over th ...

AMER CHEMICAL SOC2018

Dynamics of falling films on the outside of a vertical rotating cylinder: waves, rivulets and dripping transitions

François Gallaire, Nicolas Igor Jacques Kofman

Falling liquid films on the underside of a plate or on the outside of a rotating cylinder are subject to a destabilizing body force. The evolution of the film topology is determined by interactions between the Kapitza and the Rayleigh-Taylor instability, l ...

Cambridge University Press2017

Effective models and numerical homogenization methods for long time wave propagation in heterogeneous media

Timothée Noé Pouchon

Modeling wave propagation in highly heterogeneous media is of prime importance in engineering applications of diverse nature such as seismic inversion, medical imaging or the design of composite materials. The numerical approximation of such multiscale phy ...

EPFL2017

Assessment of the Influence of Losses on the Performance of the Electromagnetic Time Reversal Fault Location Method

Farhad Rachidi-Haeri, Mario Paolone, Gaspard Lugrin, Reza Razzaghi

Electromagnetic time reversal (EMTR) has been shown to be an efficient method for locating faults in AC and DC power grids. In the available literature, the back-propagation medium has been considered to have identical losses as the direct-time medium. How ...

Institute of Electrical and Electronics Engineers2017

Analytical Time-Domain Solution of Plane Wave Propagation Across a Viscoelastic Rock Joint

Lyesse Laloui, Jian Zhao, Yang Zou

The effects of viscoelastic filled rock joints on wave propagation are of great significance in rock engineering. The solutions in time domain for plane longitudinal ( P-) and transverse ( S-) waves propagation across a viscoelastic rock joint are derived ...

Springer Verlag2017

A vector field method on the distorted Fourier side and decay for wave equations with potentials

Joachim Krieger, Roland Donninger

We study the Cauchy problem for the one-dimensional wave equation

\partial_t^2 u(t,x)-\partial_x^2 u(t,x)+V(x)u(t,x)=0.

The potential

V

is assumed to be smooth with asymptotic behavior

V(x)\sim -\tfrac14 |x|^{-2}\mbox{ as } |x|\to \infty.

...

2016

Modelling of Mechanical Interaction in Piezoelectric Actuated Resonant System

Dan Shi

Automatic assembly system has been continuously drawing attention since the beginning of the 20th century. Parts feeding system is one of the important subsystems. The parts feeding system is used for delivering bulk parts into separated individual parts. ...

EPFL2016

Wave propagation in the vicinities of rock fractures under obliquely incident wave

Lyesse Laloui, Jian Zhao, Yang Zou, Jing Li

Though obliquely incident plane wave across rock fractures has been extensively investigated by theoretical analysis, the quantitative identification of each wave emerged from fractures has not been achieved either in numerical simulation or laboratory exp ...

Springer Verlag2016