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Concept

Chambre anéchoïque

Publications associées (22)

A framework for occupancy detection and tracking using floor-vibration signals

Ian Smith, Slah Drira

In sensed buildings, information related to occupant movement helps optimize important func-tionalities such as caregiving, energy management, and security enhancement. Typical sensing approaches for occupant tracking rely on mobile devices and cameras. Th ...

2022

Localization of Electromagnetic Interference Sources Using a Time-Reversal Cavity

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

In this article, we propose and implement a novel technique to locate electromagnetic interference (EMI) sources using the concept of time-reversal (TR) cavity. We show in an intuitive manner that reflections from the surfaces of a cavity can emulate an in ...

2021

Using footstep-induced vibrations for occupant detection and recognition in buildings

Ian Smith, Yves Sylvain Gilles Reuland, Sai Ganesh Sarvotham Pai, Slah Drira

Occupant detection and recognition support functional goals such as security, healthcare, and energy management in buildings. Typical sensing approaches, such as smartphones and cameras, undermine the privacy of building occupants and inherently affect the ...

2021

Locating Transient Directional Sources in Free Space Based on the Electromagnetic Time Reversal Technique

Farhad Rachidi-Haeri, Marcos Rubinstein

Traditional location methods such as time of arrival and direction of arrival have been widely used to locate transient radiation sources. However, these approaches neglect the directional radiation pattern of the sources. Locating directional sources is a ...

2020

Occupancy detection and tracking in buildings using floor-vibration signals

Slah Drira

In sensed buildings, information related to occupant movement helps optimize important functionalities such as security enhancement, energy management, and caregiving. Typical sensing approaches for occupant tracking rely on mobile devices and cameras. The ...

EPFL2020

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

Occupant- detection strategy using footstep-induced floor vibrations

Ian Smith, Yves Sylvain Gilles Reuland, Sai Ganesh Sarvotham Pai, Slah Drira

Identification of occupant presence and location inside buildings is essential to functional goals such as security, healthcare, and energy management. Floor-vibration measurements, induced by footstep impacts, provide a non-intrusive sensing method for oc ...

ACM2019

Is there a relationship between footstep-impact locations and measured signal characteristics?

Ian Smith, Yves Sylvain Gilles Reuland, Sai Ganesh Sarvotham Pai, Slah Drira

Building utilization can be enhanced by tracking occupants. Non-intrusive tracking of occupants using floor-vibration measurements is beneficial for many smart-building applications such as energy consumption, security enhancement, and care-giving. Also, u ...

ACM2019

Pyramic: Full Stack Open Microphone Array Architecture And Dataset

Robin Scheibler, René Beuchat

In this paper we introduce an open source and reproducible microphone array hardware design and an anechoic dataset recorded with this array. The Pyramic array has 48 microphones spread onto six identical modules connected to an FPGA-ARM combo. The arrange ...

IEEE2018

Constant-pressure sound waves in non-Hermitian disordered media

Romain Christophe Rémy Fleury, Hervé Lissek, Etienne Thierry Jean-Luc Rivet

When waves impinge on a disordered material they are back-scattered and form a highly complex interference pattern. Suppressing any such distortions of a wave’s free propagation is a challenging task with many applications in a number of different discipli ...

2018

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

Nanoscale Magnetometry with Single Fluorescent Nanodiamonds Manipulated in an Anti-Brownian Electrokinetic Trap

Metin Kayci

Studies on single-molecule spectroscopy and nanoscale detection have been remarkably driven by an interest to reveal quantum and conformational states of single particles, the intra-molecular dynamics and their response to physical observables hidden by en ...

EPFL2016

Gas sensor

Gaël André Léon Farine, Conor Joseph Slater

Gas sensor (2) for measuring properties of a gas (1), including a gas viscosity sensor (4) comprising a gas interface portion (20) in contact with the gas (1) to be measured, and a measuring chamber system (15) comprising a measuring chamber(16), a first r ...

2016

Scale Model Evaluation and Optimization of Sodar Acoustic Baffles

Fernando Porté Agel

A 21: 1 scaled sodar, operating at 40 kHz, has been built and tested in the laboratory. Sodars, which use sound scattered by turbulence to profile the lowest few hundred meters of the atmosphere, need good acoustic shielding to diminish annoyance and to re ...

American Meteorological Society2015

Structured Sparsity Models for Reverberant Speech Separation

Volkan Cevher, Hervé Bourlard, Afsaneh Asaei, Mohammad Golbabaee

We tackle the multi-party speech recovery problem through modeling the acoustic of the reverberant chambers. Our approach exploits structured sparsity models to perform room modeling and speech recovery. We propose a scheme for characterizing the room acou ...

2014

Base-Station Design for Passive UHF RFID Tags with Pulse-Width Modulated Backscattering

Catherine Dehollain, Kerem Kapucu

In this work, a base-station design is proposed for passive UHF RFID tags that use pulse-width modulation (PWM) in backscattering communication. The theoretical analysis of the PWM backscattering is presented along with the challenges it creates in the bas ...

Ieee2014

Enhancing the Performances of H-plane SIW Horn Antennas

Juan Ramon Mosig, Benjamin Fuchs, Benjamin Fuchs, Marc Esquius Morote

The performances of SIW horns antennas diminish significantly when the substrate thickness is much smaller than the free space wavelength lambda(0). Specifically, the mismatch between the antenna aperture and the air yields to unwanted back radiation and p ...

Ieee2013

Modeling (non-)uniform scattering distributions in geometrical acoustics

Dirk Schröder

In most cases, a surface is not ideally smooth. It rather contains regular and irregular dents, bumps and other textures that influence the reflection of the incident wave. A reflection on such a corrugated surface causes a frequency-dependent redirection ...

Acoustical Society of America2013

Performance of the LHCb muon system

Guido Haefeli

The performance of the LHCb Muon system and its stability across the full 2010 data taking with LHC running at root s = 7 TeV energy is studied. The optimization of the detector setting and the time calibration performed with the first collisions delivered ...

Institute of Physics2013

Study on room modal equalization at low frequencies with electroacoustic absorbers

Hervé Lissek, Romain Boulandet, Etienne Thierry Jean-Luc Rivet, Iris Rigas

Nowadays, requirements for acoustic treatments in rooms are ever more demanding in terms of performance and compactness. A recurring issue in closed spaces is the occurrence of standing waves and acoustic interferences at low frequencies. These unwanted ph ...

2012