Publications associées à Optimization of electroacoustic resonators for semi-active room equalization in the low-frequency range

Inverse Problems in Pulse-Echo Ultrasound: Exploiting Coherence for Image Enhancement and Quantitative Imaging

Whereas pulse-echo ultrasound imaging relied on focused acoustic waves since its inception, the last two decades have seen the development of techniques based on unfocused waves, including ultrafast ultrasound imaging. In large part due to the emergence of ...

EPFL2024

Observation of non-reciprocal harmonic conversion in real sounds

Romain Christophe Rémy Fleury, Hervé Lissek, 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

Ultrabroadband sound control with deep-subwavelength plasmacoustic metalayers

Romain Christophe Rémy Fleury, Hervé Lissek, Stanislav Sergeev

Controlling audible sound requires inherently broadband and subwavelength acoustic solutions, which are to date, crucially missing. This includes current noise absorption methods, such as porous materials or acoustic resonators, which are typically ineffic ...

Nature Research2023

Type-Preserving Compilation of Class-Based Languages

Guillaume André Fradji Martres

The Dependent Object Type (DOT) calculus was designed to put Scala on a sound basis, but while DOT relies on structural subtyping, Scala is a fundamentally class-based language. This impedance mismatch means that a proof of DOT soundness by itself is ...

EPFL2023

Dynamic behavior of exposed geomembrane systems in pressure waterways

Giovanni De Cesare, Samuel Luke Vorlet, Roberto Proença Seixas

Geomembrane systems have been used in dams and reservoirs as rehabilitation technology since several decades and are now used worldwide. They act as impervious layer to prevent and mitigate water leakage and damage to structures. They meet the needs of man ...

CRC Press/Balkema2023

Self-Synchronized Grid Impedance Estimation Unit using Interpolated DFT Technique

Drazen Dujic, Andrea Cervone, Jules Christian Georges Macé

Estimating the impedance of a grid-connected device or of a grid at the point of common coupling is important for evaluating the interaction between them. Impedance measurement involves a perturbation injection device, that perturbs the system, and a measu ...

2023

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

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

PID-like active impedance control for electroacoustic resonators to design tunable single-degree-of-freedom sound absorbers

Hervé Lissek, Maxime Volery, Xinxin Guo

Sound absorption at low frequencies still remains a challenge in both scientific research and engineering practice. Natural porous materials are ineffective in this frequency range, as well as acoustic resonators which present too narrow bandwidth of absor ...

2022

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