Publications associées à Haut-parleur

The Advection Boundary Law in presence of mean-flow and spinning modes

In the attempt to reduce fuel consumption, a new generation of Ultra-High-By-Pass-Ratio (UHBR) turbofans have been introduced in the aeronautic industry which are structurally noisier especially at lower frequencies, because of their larger diameter, lower ...

SPIE2024

Robust direct acoustic impedance control using two microphones for mixed feedforward-feedback controller

Hervé Lissek, Maxime Volery, Xinxin Guo

This paper presents an acoustic impedance control architecture for an electroacoustic absorber combining both feedforward and feedback microphone-based strategies on a current-driven loudspeaker. Feedforward systems enable good performance for direct imped ...

EDP SCIENCES S A2023

Testing and nonlinear modelling of industrialized light-frame wooden diaphragms including optimized nailing and nonstructural sheathing

Edisson Xavier Estrella Arcos

This article presents the outcomes of a large project towards the investigation of the lateral performance of full-scale industrialized light-frame wooden diaphragms. 10 full-scale diaphragms of 3.6 m by 2.4 m were tested under in-plane lateral loading (mo ...

Elsevier Sci Ltd2023

Robust tunable acoustic impedance control on electroacoustic resonators for aircraft noise reduction

Maxime Volery

Air traffic noise emissions are responsible for a significant part of the overall environmental noise, especially in the vicinity of airports. Exposure to environmental noise is known to negatively impact health and to be associated with cardiovascular dis ...

EPFL2023

Smart acoustic lining for UHBR technologies engine: from the design of an electroacoustic metasurface to experimental characterization under flow

Hervé Lissek, Maxime Volery

The SALUTE project aims at evaluating performance of electroacoustic metasurface, employing a surface array of controlled electroacoustic actuators, for smart acoustic lining under grazing turbulent flow to be used in UHBR Technologies Engines. Theoretical ...

Society of Photo-Optical Instrumentation Engineers (SPIE)2023

Additively Manufactured Degradable Piezoelectric Microsystems for Sensing and Actuating

Danick Briand, Luis Guillermo Villanueva Torrijo, Nicolas Francis Fumeaux, Morgan Mc Kay Monroe

The global overabundance of electronic waste and ever-increasing concerns regarding the energy-and material-intensive manufacturing processes associated with traditional electronics are driving the development of solution-processed, degradable electronics. ...

Wiley2023

Waveguide amplifier and waveguide amplifier fabrication method

Tobias Kippenberg, Xinru Ji, Zheru Qiu, Yang Liu

The present invention concerns a waveguide amplifier comprising: - at least one embedding cladding material or layer, and - at least one rare-earth ion implanted silicon nitride material or layer embedded in the at least one embedding cladding material or ...

2023

Plasma-based Electroacoustic Actuator for Broadband Sound Absorption

Stanislav Sergeev

Environmental noise, mostly related to human activities, has an immense impact on public health. The development of noise reduction technologies is paramount in addressing this problem. Because of practical and economic reasons, a compact, broadband, light ...

EPFL2022

Corona discharge actuator as an active sound absorber under normal and oblique incidence

Hervé Lissek, Stanislav Sergeev, Thomas Humbert

In the majority of active sound absorbing systems, a conventional electrodynamic loudspeaker is used as a controlled source. However, particular situations may require an actuator that is more resistant to harsh environments, adjustable in shape, and light ...

2022

Giant switchable non thermally-activated conduction in 180 degrees domain walls in tetragonal Pb(Zr,Ti)O-3

Mihai Adrian Ionescu, Igor Stolichnov, Felix Risch

Conductive domain walls in ferroelectrics offer a promising concept of nanoelectronic circuits with 2D domain-wall channels playing roles of memristors or synoptic interconnections. However, domain wall conduction remains challenging to control and pA-rang ...

Nature Portfolio2022

Numerical simulations of retrofitting interventions on timber floors in unreinforced masonry

Katrin Beyer, Igor Tomic, Ivana Bozulic

Unreinforced masonry buildings with flexible timber floors are amongst the most vulnerable building typologies for seismic loading. Though flexible diaphragms play a role in the seismic behaviour of unreinforced masonry buildings, the impact of the connect ...

2022

A Delta Sigma-Modulated Sample and Average Common-Mode Feedback Technique for Capacitively Coupled Amplifiers in a 192-nW Acoustic Analog Front-End

Kyojin Choo

This work presents an acoustic analog front-end based on a delta sigma-modulated sample and average common-mode feedback technique. The proposed feedback offers a process and temperature stable high pass (HP) frequency corner, unity dc feedback gain, and a ...

IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC2022

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

MOCCA: Modeling and Optimizing Cone-joints for Complex Assemblies

Mark Pauly, Peng Song

We present a computational framework for modeling and optimizing complex assemblies using cone joints. Cone joints are integral joints that generalize traditional single-direction joints such as mortise and tenon joints to support a general cone of directi ...

2021

Numerical Simulation of Unreinforced Masonry Buildings with Timber Diaphragms

Katrin Beyer, Francesco Vanin, Igor Tomic, Ivana Bozulic

Though flexible diaphragms play a role in the seismic behaviour of unreinforced masonry buildings, the effect of the connections between floors and walls is rarely discussed or explicitly modelled when simulating the response of such buildings. These flexi ...

2021

Geometric optimization of dielectric elastomer electrodes for dynamic applications

Herbert Shea, Bekir Aksoy, Emil Yan Garnell

Dielectric elastomers are soft actuators, made of an elastomer membrane sandwiched by compliant electrodes. Because of their high energy density and quick response, they are well suited for dynamic applications such as loudspeakers. Thanks to progress in t ...

ELSEVIER SCI LTD2021

Measuring compartmental T-2-orientational dependence in human brain white matter using a tiltable RF coil and diffusion-T-2 correlation MRI

Muhamed Barakovic

The anisotropy of brain white matter microstructure manifests itself in orientational-dependence of various MRI contrasts, and can result in significant quantification biases if ignored. Understanding the origins of this orientation-dependence could enhanc ...

2021

Predicting exposure concentrations of chemicals with a wide range of volatility and hydrophobicity in different multi-well plate set-ups

Kristin Schirmer, Julita Maria Stadnicka-Michalak

Quantification of chemical toxicity in small-scale bioassays is challenging owing to small volumes used and extensive analytical resource needs. Yet, relying on nominal concentrations for effect determination maybe erroneous because loss processes can sign ...

NATURE RESEARCH2021

Unstable tilting motion of flexibly supported gas bearing bushings

Jürg Alexander Schiffmann, Philipp Kaspar Bättig

This paper presents measurements of the motion amplitudes from flexibly supported Herringbone Grooved Journal Bearing bushings. Measurements taken in four locations on the flexibly supported bearing bushing enable the distinction between the radial and the ...

2022

Numerical investigation of optimal divertor gas baffle closure on TCV

Stefano Coda, Holger Reimerdes, Benoît Labit, Christian Gabriel Theiler, Davide Galassi, Mirko Wensing

A first set of divertor gas baffles has recently been installed in the TCV tokamak. In order to explore the physics determining the benefits and limitations of divertor baffling and to guide the design of a possible second generation of baffles, the effect ...

2020