Publications associées à Rotor machine

Nonlinear study on a rigid rotor supported by herringbone grooved gas bearings: Theory and validation

Jürg Alexander Schiffmann, Patrick Hubert Wagner, Philipp Kaspar Bättig, Wanhui Liu

The nonlinear behavior of a rigid rotor supported by herringbone grooved journal gas bearings (HGJBs) was investigated in this study. The two-dimensional narrow groove theory (2D-NGT) was adopted to model the HGJBs. A set of integrated rotor-bearing state ...

2021

Rotor Position Estimation with Hall-Effect Sensors in Bearingless Drives

Yves Perriard, Juan Patricio Tomás Peralta Fierro

The estimation of rotor position is fundamental for the commissioning of magnetically-levitated drives. The sensors required for this measurement must be close to the rotor, often requiring constructive measures that may limit the application potential of ...

IEEE2020

Integrated, Eddy-Current-Based Sensing of Rotor Position for Magnetic Levitation

Yves Perriard, Sean Thomas, Juan Patricio Tomás Peralta Fierro

Magnetically-levitated drives are compelling in applications where long-lifetime operation or process chamber encapsulation is a requirement. To exploit these advantages, contactless position sensors are needed for position information of the rotor. Off-th ...

IEEE2020

Spatially Sampled Pressure Profile Measurements in Externally Pressurized Gas Journal Bearings

Jürg Alexander Schiffmann, Eliott Philippe Guenat, Karim Magdi Zakaria Abdelrahman Shalash

Externally pressurized gas journal bearings (EPGJB) are widely adopted to support high speed rotors. This paper presents novel experimental benchmark test data which enables EPGJB model validation. Axial and circumferential pressure profile measurements ar ...

2018

Towards Low Energy Stream Ciphers

Francesco Regazzoni, Subhadeep Banik, Willi Meier

Energy optimization is an important design aspect of lightweight cryptography. Since low energy ciphers drain less battery, they are invaluable components of devices that operate on a tight energy budget such as handheld devices or RFID tags. At Asiacrypt ...

2018

Matryoshka: Hiding Secret Communication in Plain Sight

Aikaterini Argyraki, Christina Fragouli, Iris Safaka

We want to enable a pair of communicating users to exchange secret messages while hiding the fact that secret communication is taking place. We propose a linguistic steganography approach, where each human message is hidden in another human-like message. A ...

2016

Closed-loop magnetic bearing and angular velocity control of a reaction sphere actuator

Yves Perriard, Leopoldo Rossini

This article presents the first closed-loop magnetic bearing and angular velocity experimental results of a reaction sphere actuator for satellite attitude control. The proposed reaction sphere is a permanent magnet spherical actuator whose rotor is suppor ...

Pergamon-Elsevier Science Ltd2015

Revisiting Iterated Attacks in the Context of Decorrelation Theory

Serge Vaudenay, Atefeh Mashatan, Asli Bay

Iterated attacks are comprised of iterating adversaries who can make d plaintext queries, in each iteration to compute a bit, and are trying to distinguish between a random cipher C and the perfect cipher C* based on all bits. Vaudenay showed that a 2d-dec ...

2014

Procédé pour spectroscopie RMN d'échantillons solides

Geoffrey Bodenhausen, Simone Ulzega, Marc Anthony Caporini

A method for performing magnetic resonance spectroscopy on solid sample containing nuclei of interest with spin quantum number I, comprising: subjecting the sample to a static magnetic field, spinning the sample at the magic angle and broad-band excitation ...

2013

Uniform broadband excitation of crystallites in rotating solids using interleaved sequences of delays alternating with nutation

Geoffrey Bodenhausen, Simone Ulzega, Marc Anthony Caporini

In solids that are spinning about the magic angle, trains of short pulses in the manner of Delays Alternating with Nutations for Tailored Excitation (DANTE) allow one to improve the efficiency of the excitation of magnetization compared to rectangular puls ...

Academic Press Inc - Elsevier Science2012

Alternating Control Flow Reconstruction

Johannes Kinder

Unresolved indirect branch instructions are a major obstacle for statically reconstructing a control flow graph (CFG) from machine code. If static analysis cannot compute a precise set of possible targets for a branch, the necessary conservative over-appro ...

Springer2012

Broadband excitation and indirect detection of nitrogen-14 in rotating solids using Delays Alternating with Nutation (DANTE)

Geoffrey Bodenhausen, Simone Ulzega, Marc Anthony Caporini

A train of short rotor-synchronized pulses in the manner of Delays Alternating with Nutations for Tailored Excitation (DANTE) applied to nitrogen-14 nuclei (I = 1) in samples spinning at the magic angle at high frequencies (typically nu(rot) = 62.5 kHz so ...

Academic Press Inc - Elsevier Science2011

Finite Element Model of Hydro Generators Coupled to a Grid Simulation Software

Gilles Rosselet

For the simulation of electrical power systems (adjustable speed drives, wind farms, complete grids, etc.) the Kirchhoff's model is used. Each of the components of this model (transmission line, circuit breaker, electrical machines, etc.) is represented by ...

EPFL2010

Quantitative security of block ciphers : designs and cryptanalysis tools

Thomas Baignères

Block ciphers probably figure in the list of the most important cryptographic primitives. Although they are used for many different purposes, their essential goal is to ensure confidentiality. This thesis is concerned by their quantitative security, that i ...

EPFL2008

Large low speed hydrogenerators - UMP and additional damper losses in eccentricity conditions

Stefan Keller

The present thesis is an advanced contribution to the design process of large synchronous generators with high number of poles. It proposes two original contributions, the first one allowing a very precise prediction of the no-load voltage and of the no-lo ...

EPFL2007

Implantable glucose sensor : an approach based on a rotating microviscometer combined with a sensitive liquid containing dextran and Concanavalin A

For more than thirty years there has been a high demand for glucose measuring devices to replace the finger pricking methods and to improve the life quality of diabetics. Three approaches are possible, electrochemical, electromagnetic (including optical), ...

EPFL2007