Publications associées à Transformations de Galilée

Lamplighters and the bounded cohomology of Thompson's group

We prove the vanishing of the bounded cohomology of lamplighter groups for a wide range of coefficients. This implies the same vanishing for a number of groups with self-similarity properties, such as Thompson's group F. In particular, these groups are bou ...

SPRINGER BASEL AG2022

Speed-dispersion-induced alignment: A one-dimensional model inspired by swimming droplets experiments

Yang Liu

We investigate the collective dynamics of self-propelled droplets, confined in a one-dimensional microfluidic channel. On the one hand, neighboring droplets align and form large trains of droplets moving in the same direction. On the other hand, the drople ...

2020

Theory for the density of interacting quasilocalized modes in amorphous solids

Matthieu Wyart, Thomas Willem Jan de Geus, Wencheng Ji, Marko Popovic

Quasilocalized modes appear in the vibrational spectrum of amorphous solids at low frequency. Though never formalized, these modes are believed to have a close relationship with other important local excitations, including shear transformations and two-lev ...

AMER PHYSICAL SOC2019

Aberrations analysis of a Focused Plenoptic Camera

Toralf Scharf, Alessandro Grosso

A Focused Plenoptic Camera in Galilean configuration is studied and its aberrations behavior is interpreted with the Nodal Aberration Theory (NAT). Sequential ray tracing is applied to individual optical channels constituted by the camera objective and ind ...

2018

Mapping Monotone Boolean Functions into Majority

Giovanni De Micheli, Eleonora Testa, Mathias Soeken, Luca Gaetano Amarù, Winston Jason Haaswijk

We consider the problem of decomposing monotone Boolean functions into majority-of-three operations, with a particular focus on decomposing the majority-n function. When targeting monotone Boolean functions, Shannon's expansion can be expressed by a single ...

2018

Geometric robustness of deep networks: analysis and improvement

Pascal Frossard, Seyed Mohsen Moosavi Dezfooli, Can Kanbak

Deep convolutional neural networks have been shown to be vulnerable to arbitrary geometric transformations. However, there is no systematic method to measure the invariance properties of deep networks to such transformations. We propose ManiFool as a simpl ...

2018

Projective transformations of structural equilibrium

Corentin Jean Dominique Fivet

Direct methods that transform the geometry of a structure and conserve its static equilibrium are of particular interest for designers. They allow the exploration of alternative solutions at minimum computational cost. While parallel transformations (stret ...

2016

Poincaré, Scale and Conformal Symmetries : Gauge Perspective and Cosmological Ramifications

Georgios Karananas

Symmetries are omnipresent and play a fundamental role in the description of Nature. Thanks to them, we have at our disposal nontrivial selection rules that dictate how a theory should be constructed. This thesis, which is naturally divided into two parts, ...

EPFL2016

Kinetic model for calcium sulfate alpha-hemihydrate produced hydrothermally from gypsum formed by flue gas desulfurization

Xuerun Li

Modeling of the kinetics of the synthesis process for calcium sulfate alpha-hemihydrate from gypsum formed by flue gas desulfurization (FGD) is important to produce high-performance products with minimal costs and production cycles under hydrothermal condi ...

Wiley-Blackwell2015

General coordinate invariance in quantum many-body systems

Alexander Monin, Solomon G Shamsuddin Osman Endlich

We extend the notion of general coordinate invariance to many-body, not necessarily relativistic, systems. As an application, we investigate nonrelativistic general covariance in Galilei-invariant systems. The peculiar transformation rules for the backgrou ...

American Physical Society2014

On the stability of travelling waves with vorticity obtained by minimization

Boris Buffoni

We modify the approach of Burton and Toland Comm. Pure Appl. Math. LXIV. 975-1007 (2011) to show the existence of periodic surface water waves with vorticity in order that it becomes suited to a stability analysis. This is achieved by enlarging the functio ...

Springer Basel2013

Joint reconstruction of misaligned images from incomplete measurements for cardiac MRI

Pierre Vandergheynst, Gilles Puy, Gabriele Vincenzo Bonanno

We present a novel method for robust reconstruction of the image of a moving object from incomplete linear measurements. We assume that only few measurements of this object can be acquired at different instants and model the correlation between measurement ...

2013

Joint image registration and reconstruction from compressed multi-view measurements

Pierre Vandergheynst, Gilles Puy

We present a method for joint reconstruction of a set of images representing a given scene from few multi-view measurements obtained by compressed sensing. We model the correlation between measurements using global geometric transformations represented by ...

Spie-Int Soc Optical Engineering2013

Invariant Higher-Order Variational Problems

Tudor Ratiu, François Gay-Balmaz

We investigate higher-order geometric k-splines for template matching on Lie groups. This is motivated by the need to apply diffeomorphic template matching to a series of images, e.g., in longitudinal studies of Computational Anatomy. Our approach formulat ...

2012

A Theory of Slow Feature Analysis for Transformation-Based Input Signals with an Application to Complex Cells

We develop a group-theoretical analysis of slow feature analysis for the case where the input data are generated by applying a set of continuous transformations to static templates. As an application of the theory, we analytically derive nonlinear visual r ...

Massachusetts Institute of Technology Press2011

On Regularized Reconstruction of Vector Fields

Michaël Unser, Pouya Dehghani Tafti

In this paper, we give a general characterization of regularization functionals for vector field reconstruction, based on the requirement that the said functionals satisfy certain geometric invariance properties with respect to transformations of the coord ...

IEEE2011

Fractional Brownian Models For Vector Field Data

Michaël Unser, Pouya Dehghani Tafti

In this note we introduce a vector generalization of fractional Brownian motion. Our definition takes into account directional properties of vector fields-such as divergence, rotational behaviour, and interactions with coordinate transformations-that have ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2010

Alignment of Multiple Configurations Using Hierarchical Models

Yann Ruffieux

We describe a method for aligning multiple unlabeled configurations simultane- ously. Specifically, we extend the two-configuration matching approach of Green and Mardia (2006) to the multiple configuration setting. Our approach is based on the in- troduct ...

2009

Three Dimensional Frames of References Transformations using Recurrent Populations of Neurons

Aude Billard, Eric Sauser

This work investigates whether population vector coding, a distributed computational paradigm, could be a principle mechanism for performing sensorimotor and frames of reference transformations. This paper presents a multilayer neural network that can perf ...

2005

Multivariable design of bilateral Master-Slave force reflecting servomechanisms

Bilateral Master-Slave force reflecting servomechanisms are very interesting and useful devices. The basic principle of these systems is too realise a force and position transformation between the two mechanisms. This paper presents the design of the multi ...

1997