Publications associées à A sound diffusion system for directional sound enhancement

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

Circularly polarized planar antenna with axially symmetric beamwidth reconfigurability

Anja Skrivervik, Ismael Vico Triviño, Hannes Bartle

This contribution presents the design of a compact circularly polarized antenna featuring beamwidth reconfiguration in both the horizontal and vertical planes. The observed radiation patterns in each of the reconfigurable states present axial symmetry and ...

IEEE2023

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

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

Analysis of Non-Canonical Body-Conformal Arrays with Polarization Decomposition

Anja Skrivervik, Denys Nikolayev

Conformal phased arrays can be found in many applications due to their ability to fit tridimensional surfaces and, thanks to their scanning performance, can excel planar arrays. However, most of the previously proposed analysis methods can be applied only ...

IEEE2023

Measuring the electron energy distribution in tokamak plasmas from polarized electron cyclotron radiation

Arsène Stéphane Tema Biwole

In this doctoral thesis, a promising technique has been used for the measurement of non-thermal electrons in TCV. The technique employs a Vertical viewing ECE to more easily discriminate the radiation according to the energy of the electrons. Successful ...

EPFL2023

Ultrabroadband sound control with deep-subwavelength plasmacoustic metalayers

Hervé Lissek, Romain Christophe Rémy Fleury, 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

Radiation Patterns of RF Wireless Devices Implanted in Small Animals: Unexpected Deformations Due to Body Resonance

Anja Skrivervik, Stéphanie Lacour, James Daniel Rosenthal, Mingxiang Gao, Kangling Wu, Zvonimir Sipus, German Augusto Ramirez Arroyave

One challenge in designing RF wireless bioelectronic devices is the impact of the interaction between electromagnetic waves and host body tissues on far-field wireless performance. In this paper, we investigate a peculiar phenomenon of implantable RF wirel ...

2023

Hints of the Photonic Nature of the Electromagnetic Fields in Classical Electrodynamics

Farhad Rachidi-Haeri, Marcos Rubinstein

Several recent publications show that the electromagnetic radiation generated by transmitting antennas satisfy the following universal conditions: The time domain radiation fields satisfy the condition A ≥ h/4π ⇒ q ≥ e where A is the action of the radiatio ...

2023

Auditory externalization of a remote microphone signal

Vincent Pierre Olivier Grimaldi

A remote microphone (RM) system can be used in combination with wearable binaural communication devices, such as hearing aids (HAs), to improve speech intelligibility. Typically, a speaker is equipped with a body-worn microphone which enables to pick up th ...

EPFL2022

Multi-antenna 3D pattern design for millimeter-wave vehicular communications

German Augusto Ramirez Arroyave

The transformation of the automotive industry towards ubiquitous connection of vehicles with all kind of external agents (V2X) motivates the use of a wide range of frequencies for several applications. Millimeter-wave (mmWave) connectivity represents a par ...

2022

Sound and Complete Verification of Polynomial Networks

Volkan Cevher, Mehmet Fatih Sahin, Grigorios Chrysos, Fanghui Liu, Elias Abad Rocamora

Polynomial Networks (PNs) have demonstrated promising performance on face and image recognition recently. However, robustness of PNs is unclear and thus obtaining certificates becomes imperative for enabling their adoption in real-world applications. Exist ...

2022

Blind as a Bat: Audible Echolocation on Small Robots

Martin Vetterli, Mihailo Kolundzija, Frederike Dümbgen, Adrien Guillaume Olivier Hoffet, Adam James Scholefield

For safe and efficient operation, mobile robots need to perceive their environment, and in particular, perform tasks such as obstacle detection, localization, and mapping. Although robots are often equipped with microphones and speakers, the audio modality ...

2022

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

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

Inverse design of diffractive optical elements using step-transition perturbation approach

Toralf Scharf, Dong Cheon Kim

Diffractive optical elements are ultra-thin optical components required for a variety of applications because of their high design flexibility. We introduce a gradient-based optimization method based on a step-transition perturbation approach which is an e ...

WALTER DE GRUYTER GMBH2021

Uncertain Sampling with Certain Priors

Golnooshsadat Elhami

Sampling has always been at the heart of signal processing providing a bridge between the analogue world and discrete representations of it, as our ability to process data in continuous space is quite limited. Furthermore, sampling plays a key part in unde ...

EPFL2021

Characterization of Non-Stationary Signals in Electric Grids: a Functional Dictionary Approach

Mario Paolone, Asja Derviskadic, Guglielmo Frigo, Alexandra Cameron Karpilow

With the expanding role of converter-interfaced distributed energy resources, modern power grids are evolving towards low-inertia networks that are increasingly vulnerable to extreme dynamics. Consequently, advanced signal processing techniques are needed ...

IEEE Institute of Electrical and Electronics Engineers2021

A portable picocell antenna for 5G

Danelys Rodríguez Avila

Deployable emergency communication systems are a backbone solution for replacing damaged network infrastructures and/or providing high-end services in case of an emergency event. It is important that such systems are up-to-date with the latest mobile netwo ...

EPFL2021

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