Publications associées à Signal reflection

Electromagnetic time reversal for online partial discharge location in power cables: Influence of interfering reflections from grid components

In online single-sided partial discharge (PD) location, the measured PD reflection patterns are affected by the characteristics of all the components of the associated power network. This paper analyses the performance of a PD location method based on elec ...

2024

Dielectric Elastomer Actuator-Based Valveless Impedance-Driven Pumping for Meso- and Macroscale Applications

Yves Perriard, Yoan René Cyrille Civet, Thomas Guillaume Martinez, Francesco Clavica, Armando Matthieu Walter, Amine Benouhiba, Silje Ekroll Jahren

Impedance pumps are simple designs that allow the generation or amplification of flow. They are fluid-filled systems based on flexible tubing connected to tubing with different impedances. A periodic off-center compression of the flexible tubing causes the ...

2023

Millimeter-wave to near-terahertz sensors based on reversible insulator-to-metal phase transition in Vanadium dioxide

Fatemeh Qaderi Rahaqi

Millimeter-wave (mm-wave) and terahertz (THz) detection has opened a significant research direction in imaging, sensing, spectroscopy, and ultrafast wireless communication. The sensitivity of the phase transition to electromagnetic waves in Vanadium dioxid ...

EPFL2022

An Effective EMTR-Based High-Impedance Fault Location Method for Transmission Lines

Farhad Rachidi-Haeri, Rong Zeng

This article summarizes the electromagnetic time-reversal (EMTR) technique for fault location, and further numerically validates its effectiveness when the fault impedance is negligible. In addition, a specific EMTR model considering the fault impedance is ...

2021

Soft functional fibers for mechanical sensing and actuation

Andreas Leber

The measurement and generation of mechanical deformations is a key functionality in health monitoring, human-machine interaction, and soft robotics. However, current methods typically rely on small and hard transducers, which result in poor performance, cu ...

EPFL2021

High resolution density pedestal measurements during edge localized modes by short-pulse reflectometry in the TCV tokamak

Stefano Coda, Benoît Labit, Laurie Porte, Pedro Andres Molina Cabrera

This publication presents high spatio-temporal resolution (mm/μs) density profile measurements of the pedestal top during type I, III, and small edge localized mode (ELM) H- mode plasmas in the Tokamak à Configuration Variable (TCV). These measurements wer ...

2021

Least-Squares Padé approximation of parametric and stochastic Helmholtz maps

Fabio Nobile, Francesca Bonizzoni, Davide Pradovera

The present work deals with rational model order reduction methods based on the single-point Least-Square (LS) Padé approximation techniques introduced in Bonizzoni et al. (ESAIM Math. Model. Numer. Anal., 52(4), 1261–1284 2018, Math. Comput. 89, 1229–1257 ...

2020

Finite element modeling of dynamic frictional rupture with rate and state friction

Jean-François Molinari, Fabian Barras, Roozbeh Rezakhani, Michael Ludovic Brun

Numerous laboratory experiments have demonstrated the dependence of the friction coefficient on the interfacial slip rate and the contact history, a behavior generically called rate and state friction. Although numerical models have been widely used for an ...

PERGAMON-ELSEVIER SCIENCE LTD2020

Positional dependence of particles and cells in microfluidic electrical impedance flow cytometry: origin, challenges and opportunities

Philippe Renaud, Jonathan Bastien Cottet

Microfluidic electrical impedance flow cytometry is now a well-known and established method for single-cell analysis. Given the richness of the information provided by impedance measurements, this non-invasive and label-free approach can be used in a wide ...

2020

Controlling oscillations in high-order Discontinuous Galerkin schemes using artificial viscosity tuned by neural networks

Jan Sickmann Hesthaven, Niccolo' Discacciati, Deep Ray

High-order numerical solvers for conservation laws suffer from Gibbs phenomenon close to discontinuities, leading to spurious oscillations and a detrimental effect on the solution accuracy. A possible strategy to reduce it comprises adding a suitable amoun ...

ACADEMIC PRESS INC ELSEVIER SCIENCE2020

Mapping the site-specific accuracy of loop-based local pulse wave velocity estimation and reflection magnitude: a 1D arterial network model analysis

Nikolaos Stergiopoulos, Patrick Segers

Objective: Local pulse wave velocity (PWV) can be estimated from the waterhammer equation and is an essential component of wave separation analysis. However, previous studies have demonstrated inaccuracies in the estimations of local PWV due to the presenc ...

2019

Tokamak plasma edge studies by microwave short-pulse reflectometry and backscattering

Pedro Andres Molina Cabrera

Moving towards an increased understanding of the dynamic processes in the edge of tokamak plasmas requires continuous innovation in diagnostic capabilities, pushing the envelope in both spatial and temporal dimenstions. Plasma density and rotation, and the ...

EPFL2019

Tower and Path-Dependent Voltage Effects on the Measurement of Grounding Impedance for Lightning Studies

Marcos Rubinstein, Antonio Sunjerga, Hamidreza Karami, Keyhan Sheshyekani

We present an analysis aimed at evaluating the effect of the presence of the tower on the measurement of the grounding impedance. The Numerical Electromagnetics Code NEC-4 is used for the full-wave modeling of the structure including the tower and its foot ...

2019

Urine-Contactless Device to Empty Bladders: an Ex-Vivo Proof-of-Concept Study in Porcine Bladders

Yves Perriard, Yoan René Cyrille Civet, Francesco Clavica

Current treatments for underactive bladder (UAB) have negative side effects, such as urinary tract infections, mainly because devices used for bladder emptying are in direct contact with urine (e.g. permanent or intermittent catheterisation). Moreover, mos ...

Wiley2019

Pulse Reflectometer and Doppler back-scattering diagnostics in the TCV Tokamak

Stefano Coda, Laurie Porte, Pedro Andres Molina Cabrera

Latest DBS and Pulse reflectometer developments in the TCV tokamak are presented ...

2018

Study of the Propagation of Common Mode IEMI Signals Through Concrete Walls

Farhad Rachidi-Haeri, Marcos Rubinstein, Nicolas Mora Parra, Gaspard Lugrin

In this paper, a model to analyze the propagation of intentional electromagnetic interferences disturbances along penetrating conductors into concrete walls is proposed. The model is based on the transmission line theory and considers the attenuation of th ...

Institute of Electrical and Electronics Engineers2018

Site-controlled quantum dots coupled to photonic crystal waveguides

Elyahou Kapon, Alok Rudra, Benjamin Dwir, Alexey Lyasota, Clément William Tendaï Jarlov, Bruno Marie Dominique Rigal, Irina Kulkova, Jakob Rosenkrantz De Lasson, Jesper Mork

We demonstrate selective optical coupling of multiple, site controlled semiconductor quantum dots (QDs) to photonic crystal waveguide structures. The impact of the exact position and emission spectrum of the QDs on the coupling efficiency is elucidated. Th ...

2016

Locating transient disturbance sources and modelling their interaction with transmission lines : use of electromagnetic time reversal and asymptotic theory

Gaspard Lugrin

This thesis deals with the application of electromagnetic time reversal to locating transient disturbance sources and the use of the asymptotic theory for the modelling of their interaction with transmission lines. We demonstrate that the time-of-arrival, ...

EPFL2016

Complex image method for RF antenna-plasma inductive coupling calculation in planar geometry. Part I: basic concepts

Ivo Furno, Alan Howling, Philippe Frédérique Bruno Guittienne, Rémy Jacquier

The coupling between an inductive source and the plasma determines the power transfer efficiency and the reflected impedance in the primary circuit. Usually, the plasma coupling is analysed by means of a transformer equivalent circuit, where the plasma ind ...

Iop Publishing Ltd2015

Miniature silicon Michelson interferometer characterization for dimensional metrology

Maurine Malak Karam Awadallah

Dimensional metrology applications require performing measurements of profile and form/shape of parts at a nanometer-level of accuracy. Therefore, the metrological characteristics of a miniature optical micro-probe based on a Michelson interferometer are e ...

Elsevier Science Sa2015