Publications associées à Line-of-sight data transmission system based on Mid IR quantum cascade laser

Observation of non-reciprocal harmonic conversion in real sounds

Hervé Lissek, Romain Christophe Rémy Fleury, Xinxin Guo

Reciprocity guarantees that in most media, sound transmission is symmetric between two points of space when the location of the source and receiver are interchanged. This fundamental law can be broken in non-linear media, often at the cost of detrimental i ...

2023

Lightning interaction with the ionosphere

Farhad Rachidi-Haeri, Marcos Rubinstein, Dongshuai Li

Lightning discharges, including cloud-to-ground (CG) and intracloud (IC) lightning, are known to emit electromagnetic pulses (EMPs) in a wide frequency band ranging from few Hz up to hundreds MHz [1]. During the breakdown and ionization processes (mostly f ...

IET2023

Scattering from Time-Modulated Transmission-Line Loads: Theory and Experiments in Acoustics

Romain Christophe Rémy Fleury, Matthieu Francis Malléjac

Scattering wave systems that are periodically modulated in time offer many new degrees of freedom to control waves in both the spatial and frequency domains. Such systems, albeit linear, do not conserve frequency and require the adaptation of the usual the ...

American Physical Society (APS)2023

DG-Mix: Domain Generalization for Anomalous Sound Detection Based on Self-Supervised Learning

Ismail Nejjar, Olga Fink, Gaëtan Michel Frusque

Detecting anomalies in sound data has recently received significant attention due to the increasing number of implementations of sound condition monitoring solutions for critical assets. In this context, changing operating conditions impose significant dom ...

2022

Sound Field Reconstruction in a room through Sparse Recovery and its application in Room Modal Equalization

Vu Thach Pham

The acoustics of a room often refer to the quality of the room in terms of sound recording as well as sound reproduction. At low frequencies, where the wavelengths are of the same order of magnitude with the dimensions of the room, due to the standing wave ...

EPFL2021

Electrical Signal Modeling in Cochlear Implants. Study of Temperature and Humidity Effects

Maria-Alexandra Paun

The present paper discusses the climatic effects of humidity and temperature on cochlear implant functioning and the quality of the electrical sound signal. MATLAB Simulink simulations were prepared, offering insights into signal behavior under such climat ...

MDPI2021

Emittance growth suppression with a multibunch feedback in high-energy hadron colliders: Numerical optimization of the gain and bandwidth

Xavier Buffat, Sondre Vik Furuseth

A transverse feedback system can effectively mitigate the emittance growth caused by injection oscillations and machine noise in hadron beams. However, as its action on the beam depends on beam position measurements of finite accuracy, it introduces additi ...

2021

Machine Learning-Based Lightning Localization Algorithm Using Lightning-Induced Voltages on Transmission Lines

Farhad Rachidi-Haeri, Marcos Rubinstein, Mohammad Azadifar, Hamidreza Karami, Amirhossein Mostajabi

In this article, we present a machine learning-based method to locate lightning flashes using calculations of lightning induced voltages on a transmission line. The proposed approach takes advantage of the preinstalled voltage measurement systems on power ...

2020

Low frequency sound field reconstruction in a non-rectangular room using a small number of microphones

Hervé Lissek, Vu Thach Pham

An accurate knowledge of the sound field distribution inside a room is required to identify and optimally locate corrective measures for room acoustics. However, the spatial recovery of the sound field would result in an impractically high number of microp ...

2020

Good Vibrations and Unknown Excitations

Dalia Salem Hassan Fahmy El Badawy

Inspired by the human ability to localize sounds, even with only one ear, as well as to recognize objects using active echolocation, we investigate the role of sound scattering and prior knowledge in regularizing ill-posed inverse problems in acoustics. In ...

EPFL2020

Improving sound absorption through nonlinear active electroacoustic resonators

Hervé Lissek, Romain Christophe Rémy Fleury, Xinxin Guo

Absorbing airborne noise at frequencies below 300 Hz is a particularly vexing problem due to the absence of natural sound absorbing materials at these frequencies. The prevailing solution for low-frequency sound absorption is the use of passive narrow-band ...

American Physical Society (APS)2020

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

Marcos Rubinstein, Keyhan Sheshyekani, Hamidreza Karami, Antonio Sunjerga

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

Theory for the density of interacting quasilocalized modes in amorphous solids

Marko Popovic, Matthieu Wyart, Wencheng Ji, Thomas Willem Jan de Geus

Quasilocalized modes appear in the vibrational spectrum of amorphous solids at low frequency. Though never formalized, these modes are believed to have a close relationship with other important local excitations, including shear transformations and two-lev ...

AMER PHYSICAL SOC2019

AltitudeOmics: Spontaneous Baroreflex Sensitivity During Acclimatization to 5,260 m: A Comparison of Methods

Jean-Marc Vesin, Sasan Yazdani

Introduction Baroreflex sensitivity (BRS) is essential to ensure rapid adjustment to variations in blood pressure (BP). Spontaneous baroreflex function can be assessed using continuous recordings of blood pressure. The goal of this study was to compare fou ...

2019

Time-Frequency Characterization of Resting-State Brain Function Reveals Overlapping Components with Specific Topology and Frequency Content

Dimitri Nestor Alice Van De Ville, Thomas William Arthur Bolton

Even at rest, functional magnetic resonance imaging (fMRI) data displays exquisitely complex temporal dynamics. Here, we deployed a time-frequency analysis to track the modulus of fMRI signals over time, across space (a set of 341 brain areas) and frequenc ...

ASSOC COMPUTING MACHINERY2019

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

Low Frequency Sound Field Reconstruction in Non-rectangular Room: A Numerical Validation

Hervé Lissek, Etienne Thierry Jean-Luc Rivet, Vu Thach Pham

Characterization of sound fields in rooms has always been a challenging task. A faithful reconstruction of sound fields in rooms generally would require an impractically high number of microphones. At low frequencies, where sound field can be modeled as a ...

2018

Neural encoding of auditory features during music perception and imagery

José del Rocio Millán Ruiz, Stéphanie Martin

Despite many behavioral and neuroimaging investigations, it remains unclear how the human cortex represents spectrotemporal sound features during auditory imagery, and how this representation compares to auditory perception. To assess this, we recorded ele ...

2018

Localization of emergency acoustic sources by micro aerial vehicles

Dario Floreano, Meysam Basiri, Felix Stephan Schill

For micro aerial vehicles (MAVs) involved in search and rescue missions, the ability to locate the source of a distress sound signal is significantly important and allows fast localization of victims and rescuers during nighttime, through foliage and in du ...

John Wiley & Sons2017

Room Modal Equalisation with Electroacoustic Absorbers

Etienne Thierry Jean-Luc Rivet

The sound quality in a room is of fundamental importance for both recording and reproducing processes. Because of the room modes, the distributions in space and frequency of the sound field are largely altered. Excessive rise and decay times caused by the ...

EPFL2016