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Publications associées (28)

Vlasov description of the beam response to noise in the presence of wakefields in high-energy synchrotrons: beam transfer function, diffusion, and loss of Landau damping

Noise can have severe impacts on particle beams in high-energy synchrotrons. In particular, it has recently been discovered that noise combined with wakefields can cause a diffusion that leads to a loss of Landau damping after a latency. Such instabilities ...

SPRINGER HEIDELBERG2022

Effect of illumination and applied potential on the electrochemical impedance spectra in triple cation (FA/MA/Cs) 3D and 2D/3D perovskite solar cells

Mohammad Khaja Nazeeruddin, Sanghyun Paek

Even though there has been numerous works performed based on electrochemical impedance spectroscopy (EIS) of perovskite solar cells (PSCs), however, many aspects of the obtained EI spectra are yet to be fully grasped. Moreover, the change of these spectra ...

ELSEVIER SCIENCE SA2021

Low Noise Clock Generation: Modeling, Analysis and Implementation

Duygu Kostak

The aim of this thesis is to implement, analyze and improve the selected low noise clock generation and distribution techniques for ADC implementations. The thesis is divided into two parts. The first part focuses on the sampling phase generation and distr ...

EPFL2021

Stabilization and Performance Improvement of Power-Hardware-in-the-Loop Test Using a Robust Data-Driven Method

Alireza Karimi, Seyed Sohail Madani

Power-Hardware-in-the-Loop (PHIL) setups have gained high importance in validation of the performance of newly developed instruments and devices with low risk and implementation cost. However, the interconnection of a power hardware with a simulated model ...

2022

Loss of transverse Landau damping by noise and wakefield driven diffusion

Xavier Buffat, Sondre Vik Furuseth

Landau damping of coherent modes is strongly dependent on the exact shape of the particle bunches. One often assumes that the transverse distributions in high-energy hadron colliders can be approximated by Gaussian distributions, in acceptable agreement wi ...

2020

Two-degrees-of-freedom (PID)-D-2 controller for precise nanopositioning in the presence of hardware-induced constant time delay

Andres San Millan Rodriguez

The fast and accurate tracking of periodic and arbitrary reference trajectories is the principal goal in many nanopositioning applications. Flexure-based piezoelectric stack driven nanopositioners are widely employed in applications where accurate mechanic ...

ELSEVIER SCIENCE INC2019

A Root-Locus Design Methodology Derived From the Impedance/Admittance Stability Formulation and Its Application for LCL Grid-Connected Converters in Wind Turbines

Francisco Daniel Freijedo Fernández

This paper presents a systematic methodology for the design and the tuning of the current controller in LCL grid-connected converters for wind turbine applications. The design target is formulated as a minimization of the current loop dominant time constan ...

Ieee-Inst Electrical Electronics Engineers Inc2017

Fixed-order loop shaping robust controller design for parametric models to damp inter-area oscillations

Alireza Karimi

The inter-area oscillations are common in power systems and can occur due to the changes in the load or generating power especially in long transmission lines. This paper presents the design of a robust fixed order loop shaping controller to damp out the i ...

Elsevier Sci Ltd2017

Design of a Fixed-Order Robust Controller Using Loop Shaping Method for Damping Inter-Area Oscillations in Power Systems

Alireza Karimi

The inter-area oscillations are common in power system and can occur due to the changes in the load or generation power especially in long transmission lines. This paper presents the design of a robust fixed-order loop shaping controller to damp out the in ...

Ieee2016

Effective Delivery of Analytes with Optofluidics for Ultrasensitive Biodetection

Hatice Altug, Min Huang

We present a plasmonic nanobiosensor offering superior analyte delivery efficiency. Our experiments with virus-like analytes show more than an order of magnitude faster response time, and seven orders-of-magnitude dynamic concentration range for 10(3)-10(9 ...

IEEE2014

From Fixed-Order Gain-Scheduling to Fixed-Structure LPV Controller Design

Zlatko Emedi

This thesis focuses on the development of some fixed-order controller design methods in the gain-scheduling/Linear Parameter Varying (LPV) framework. Gain-scheduled controllers designed using frequency-domain Single Input Single Output (SISO) models are co ...

EPFL2014

H-Infinity Gain-Scheduled Controller Design for Rejection of Time-Varying Disturbances with Application to an Active Suspension System

Alireza Karimi, Zlatko Emedi

A new method for H-infinity gain-scheduled controller design by convex optimization is proposed that uses only frequency-domain data. The method is based on loop shaping in the Nyquist diagram with constraints on the weighted infinity norm of closed-loop t ...

2013

H infinity Gain-scheduled Controller Design for Rejection of Time-varying Narrow-band Disturbances Applied to a Benchmark Problem

Alireza Karimi, Zlatko Emedi

Lavoisier2013

A solution to the flexible transmission benchmark by convex optimization

Alireza Karimi, Gorka Galdos Sanz de Galdeano

The flexible transmission benchmark was proposed in the European Journal of Control to evaluate some robust digital control approaches in 1995. With progress in convex optimization algorithms new methods for robust controller design are developed. A recent ...

SAGE Publications2012

Stabilization of the cart-pendulum system through approximate manifold decomposition

Dominique Bonvin, Philippe Müllhaupt, David Ingram

This paper proposes a feedback law capable of swinging up and stabilizing the cartpendulum system. The approach uses an iterative algorithm that is typically used to construct a locally linearizing output for nonlinear control-affine systems. However, rath ...

2011

Polymer-electrolyte gated graphene transistors for analog and digital phase detection

Klaus Kern, Marko Burghard, Kannan Balasubramanian

We present an alternating current (ac) circuit based on a misoriented bilayer graphene device for analog and digital phase detection. We exploit the ambipolar nature of the transfer characteristics of a misoriented bilayer graphene transistor. The transist ...

AIP American Institute of Physics2011

Polaronic Conductivity in the Photoinduced Phase of 1T-TaS2

Helmuth Berger

The transient optical conductivity of photoexcited 1T-TaS2 is determined over a three-order-of-magnitude frequency range. Prompt collapse and recovery of the Mott gap is observed. However, we find important differences between this transient metallic state ...

2011

H∞ Controller Design for Spectral MIMO Models by Convex Optimization

Alireza Karimi, Roland Longchamp, Gorka Galdos Sanz de Galdeano

A new method for robust ﬁxed-order H∞ controller design by convex optimization for multivariable systems is investigated. Linear Time-Invariant Multi-Input Multi- Output (LTI-MIMO) systems represented by a set of complex values in the frequency domain are ...

Elsevier2010

H-infinity Controller Design for Spectral MIMO Models by Convex Optimization

Alireza Karimi, Roland Longchamp, Gorka Galdos Sanz de Galdeano

A recent method for robust fixed-order H-infinty controller design by convex optimization proposed in [1] is investigated in this paper for the tuning of multivariable controllers. Linear Time-Invariant Multi-Input Multi-Output (LTI-MIMO) systems represent ...

2009

102-GHz AlInN/GaN HEMTs on Silicon With 2.5-W/mm Output Power at 10 GHz

Nicolas Grandjean, Jean-François Carlin, Eric Feltin

Grown on a (111) high-resistivity silicon substrate, 0.1-mu m gate AlInN/GaN high-electron mobility transistors (HEMTs) achieve a maximum current density of 1.3 A/mm, an extrinsic transconductance of 330 mS/mm, and a peak current gain cutoff frequency as h ...

Institute of Electrical and Electronics Engineers2009