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Concept

Damping factor

Related publications (25)

Room-temperature quantum optomechanics using an ultralow noise cavity

Tobias Kippenberg, Guanhao Huang, Nils Johan Engelsen, Alberto Beccari

At room temperature, mechanical motion driven by the quantum backaction of light has been observed only in pioneering experiments in which an optical restoring force controls the oscillator stiffness1,2. For solid-state mechanical resonators in which oscil ...

Nature Portfolio2024

Multi-scale experimental testing on variable stiffness and damping components for semi-active structural control

Gennaro Senatore

This paper presents experimental testing of a new semi-active vibration control device comprising a shape memory polymer (SMP) core that is reinforced by an SMP-aramid composite skin. This control device works as a load-transfer component that can be integ ...

ELSEVIER SCI LTD2022

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

Seismic control performance of a three-story frame prototype equipped with semi-active variable stiffness and damping structural joints

Gennaro Senatore

This paper presents numerical and experimental studies on semi-active seismic response control of structures equipped with variable stiffness and damping structural joints. Such adaptive joints, which are comprised of a shape memory polymer (SMP) core rein ...

WILEY2021

Hardware-in-the-Loop Characterization of Source-Affected Output Characteristics of Cascaded H-Bridge Converter

Drazen Dujic, Marko Petkovic

Recent trends in power system design such as an increasing share of renewable energy sources and integration of power electronics equipment for medium voltage applications are creating different subsystem interactions that require proper investigation, und ...

2021

Broadband Low-Frequency Electroacoustic Absorbers Through Hybrid Sensor-/Shunt-Based Impedance Control

Hervé Lissek, Sami Driss Karkar, Etienne Thierry Jean-Luc Rivet

This paper proposes a hybrid impedance control architecture for an electroacoustic absorber, that combines an improved microphone-based feedforward control with a currentdriven electrodynamic loudspeaker system. Feedforward control architecture enables sta ...

Institute of Electrical and Electronics Engineers2017

Design of active Multiple-degrees-of-freedom electroacoustic resonators for use as broadband sound absorbers

Hervé Lissek, Sami Driss Karkar, Romain Boulandet, Etienne Thierry Jean-Luc Rivet

We present a novel control method achieving stable multiple-degrees-of-freedom electroacoustic resonators. Such broadband absorbers, composed of a feedback-controlled electrodynamic loudspeaker, have many practical applications to real-world acoustic engin ...

2017

On the Optimisation of Multi-Degree-of-Freedom Acoustic Impedances of Low-Frequency Electroacoustic Absorbers for Room Modal Equalisation

Hervé Lissek, Sami Driss Karkar, Etienne Thierry Jean-Luc Rivet

Low-frequency electroacoustic absorbers have recently been developed as a solution for the modal equalisation. Firstly investigated in waveguides, the technique consists in matching the acoustic impedance at a closed-box loudspeaker diaphragm to the charac ...

2017

Modeling and evaluation of damping coefficient of eddy current dampers in rotordynamic applications

Eddy current dampers (ECD) can be used to introduce damping in rotordynamic applications. ECD5 are contactless in nature and can be made to introduce negligible drag force, thus being a perfect match for passive magnetic bearings such as permanent magnet b ...

Academic Press Ltd- Elsevier Science Ltd2016

Sensorless Electroacoustic Absorbers Through Synthesized Impedance Control for Damping Low-Frequency Modes in Cavities

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

This paper presents a concept of sensorless electroacoustic absorber for damping the low-frequency modes in a cavity such as a duct or a room. Taking advantage of the reciprocity of the voice coil transducer, it is shown that a synthetic electrical admitta ...

S Hirzel Verlag2016

Small-signal transient response and turn-on delay of polariton laser diodes

Raphaël Butté

We present a theoretical description of the small-signal transient response of polariton laser diodes (pol-LDs) based on simplified coupled rate equations describing the exciton reservoir and the ground-state polariton populations. The analytic expressions ...

Iop Publishing Ltd2016

Hand Impedance Measurements During Interactive Manual Welding With a Robot

Aude Billard, Mustafa Suphi Erden

This paper presents a study of hand impedance measurements comparatively across ten professional and 14 novice manual welders, when they are performing tungsten inert gas (TIG) welding interactively with the KUKA lightweight robot arm (LWR). The results sh ...

Ieee-Inst Electrical Electronics Engineers Inc2015

Ultra Fine-Pitch TSV Technology for Ultra-Dense High-Q RF Inductors

Mihai Adrian Ionescu, Montserrat Fernandez-Bolanos Badia, Wolfgang Amadeus Vitale

We demonstrate that fine-pitch TSV technology can be exploited to fabricate micro-inductors on high resistivity substrate, with record-high inductance per area and preserving their performance at GHz frequencies. We report an extensive experimental study o ...

2015

End-Point Impedance Measurements Across Dominant and Nondominant Hands and Robotic Assistance with Directional Damping

Aude Billard, Mustafa Suphi Erden

The goal of this paper is to perform end-point impedance measurements across dominant and nondominant hands while doing airbrush painting and to use the results for developing a robotic assistance scheme. We study airbrush painting because it resembles in ...

Institute of Electrical and Electronics Engineers2015

High Frequency Effects of Impedances and Coatings in the CLIC Damping Rings

Eirini Koukovini Platia

The Compact Linear Collider (CLIC) is a 3 TeV e+e- machine, currently under design at CERN, that targets to explore the terascale particle physics regime. The experiment requires a high luminosity of 2x10^34 cm^2 s^-1, which can be achieved with ultra low ...

EPFL2015

Toward broadband electroacoustic resonators through optimized feedback control strategies

Hervé Lissek, Romain Boulandet

This paper presents a methodology for the design of broadband electroacoustic resonators for low-frequency room equalization. An electroacoustic resonator denotes a loudspeaker used as a membrane resonator, the acoustic impedance of which can be modified t ...

Elsevier2014

Electroacoustic absorbers for the low-frequency modal equalization of a room: what is the optimal target impedance for maximum modal damping, depending on the total area of absorbers?

Hervé Lissek, Etienne Thierry Jean-Luc Rivet, Sami Driss Karkar, Véronique Adam

Electroacoustic absorbers consist of loudspeakers, shunted with an electrical circuit designed to obtain a given acoustic impedance. Their design and principles are now well understood. Unidimensional experiments, using plane waves under normal incidence i ...

2014

Feeding structure influence on performance of two UWB antennas near a human arm

Anja Skrivervik, Mohsen Koohestani

This paper reports a study of the feeding structure influence on impedance matching and system fidelity factor of two loaded UWB antennas when placed near a human arm. To this aim, two identical dielectric loaded versions of the same UWB antenna designs wi ...

2014

Design, Realization, and Experimental Test of a Coaxial Exponential Transmission Line Adaptor for a Half-Impulse Radiating Antenna

Farhad Rachidi-Haeri, Nicolas Mora Parra

This paper describes the simulation, design, realization, and experimental test of a tapered transmission line (TL) for adapting a broad-band impulse generator to a radiating antenna, for a frequency range of 50 MHz-1 GHz. Two different taper geometries ar ...

Ieee-Inst Electrical Electronics Engineers Inc2013

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