Publications associées à Crossing velocities for an annealed random walk in a random potential

Mean value theorems for collections of lattices with a prescribed group of symmetries

Euclidean lattices are mathematical objects of increasing interest in the fields of cryptography and error-correcting codes. This doctoral thesis is a study on high-dimensional lattices with the motivation to understand how efficient they are in terms of b ...

EPFL2024

On the Mordell-Weil lattice of y(2) = x(3) + bx plus t(3n+1) in characteristic 3

Gauthier Leterrier

We study the elliptic curves given by y(2) = x(3) + bx + t(3n+1) over global function fields of characteristic 3 ; in particular we perform an explicit computation of the L-function by relating it to the zeta function of a certain superelliptic curve u(3) ...

SPRINGER INT PUBL AG2022

How to polarise an interface with ions: the discrete Helmholtz model

Hubert Girault, Astrid Johana Olaya Avendano, Grégoire Clément Gschwend

The distribution of electrolytes in an electric field usually relies on theories based on the Poisson-Boltzmann formalism. These models predict that, in the case of a metallic electrode, ionic charges screen the electrode potential, leading to concentratio ...

2020

New Results in Integer and Lattice Programming

Christoph Hunkenschröder

An integer program (IP) is a problem of the form

\min \{f(x) : \, Ax = b, \ l \leq x \leq u, \ x \in \Z^n\}

, where

A \in \Z^{m \times n}

,

b \in \Z^m

,

l,u \in \Z^n

, and

f: \Z^n \rightarrow \Z

is a separable convex objective function. The problem o ...

EPFL2020

Electrochemical potential window of battery electrolytes: the HOMO-LUMO misconception

Hubert Girault, Pekka Eero Peljo

A widespread misconception in the lithium ion battery literature is the equality of the energy difference of HOMO and LUMO of the solvent with the electrochemical stability window. HOMO and LUMO are concepts derived from approximated electronic structure t ...

2018

A variational investigation of the SU(N) Heisenberg model in antisymmetric irreducible representations

Jérôme Dufour

Motivated by recent experimental progress in the context of ultra-cold multi-colour fermionic atoms in optical lattices, this thesis investigates the properties of the antiferromagnetic SU(N) Heisenberg models with fully antisymmetric irreducible represent ...

EPFL2016

Towards large-scale commercialization of fuel cells : robust design optimization considering dimensional uncertainties in the flow distributors

Thierry Mikaël Cornu

The present and future challenges that humanity is facing regarding consumption and supply of energy constitute the context of this research. The technology in which we are interested is the fuel cell, mainly because of its high efficiency for the conversi ...

EPFL2016

A sieve algorithm based on overlattices

Anja Annemone Becker

In this paper, we present a heuristic algorithm for solving exact, as well as approximate, shortest vector and closest vector problems on lattices. The algorithm can be seen as a modified sieving algorithm for which the vectors of the intermediate sets lie ...

Cambridge Univ Press2014

On the number of lattice points in a small sphere and a recursive lattice decoding algorithm

Annika Meyer

Let L be a lattice in . This paper provides two methods to obtain upper bounds on the number of points of L contained in a small sphere centered anywhere in . The first method is based on the observation that if the sphere is sufficiently small then the la ...

Springer US2013

Unified Detection and Tracking of Instruments during Retinal Microsurgery

Raphael Sznitman

Methods for tracking an object have generally fallen into two groups: tracking by detection and tracking through local optimization. The advantage of detection-based tracking is its ability to deal with target appearance and disappearance, but it does not ...

Ieee Computer Soc2013

Monte Carlo modeling of crystal channeling at high energies

Alessio Ferrari, Philippe Jean Schoofs, Francesco Cerutti

Channeling in bent crystals is becoming a reliable and efficient technique for collimating beams. At CERN, the installation of crystals in LHC is under scrutiny by the UA9 collaboration with the goal of investigating if they are a viable option for the col ...

Elsevier2013

Elasto-static micropolar behavior of a chiral auxetic lattice

Alessandro Spadoni

Auxetic materials expand when stretched, and shrink when compressed. This is the result of a negative Poisson's ratio ν. Isotropic configurations with ν≈−1 have been designed and are expected to provide increased shear stiffness G. This assumes that Young' ...

Elsevier2012

Lattice symmetries and regular magnetic orders in classical frustrated antiferromagnets

We consider some classical and frustrated lattice spin models with global O(3) spin symmetry. No general analytical method to find a ground state exists when the spin dependence of the Hamiltonian is more than quadratic (i.e., beyond the Heisenberg model) ...

2011

Modeling and Solving the Tactical Berth Allocation Problem

Matteo Salani, Ilaria Vacca

In this paper we integrate at the tactical level two decision problems arising in container terminals: the berth allocation problem, which consists of assigning and scheduling incoming ships to berthing positions, and the quay crane assignment problem, whi ...

2010

Effect of electrode potential on the tribocorrosion of tungsten

Didier Bouvet, Michel Declercq, Stefano Mischler, Jelena Stojadinovic

The tribocorrosion behavior of tungsten sliding against an alumina ball was evaluated in sulfuric acid under applied electrode potential. Surface chemistry of worn and unworn surfaces was evaluated using XPS and AES. Quasi-potentiostatic polarization curve ...

2009

Assembly and reactivity of nanoparticles at liquid / liquid interfaces

Bin Su

The interface between two immiscible electrolyte solutions (ITIES), or liquid|liquid interface, provides a defect-free junction for fundamental studies of adsorption phenomena, heterogeneous charge transfer reactions, and phase-formation processes. Recent ...

EPFL2006

Hexagonal Versus Orthogonal Lattices: A New Comparison Using Approximation Theory

Thierry Blu, Dimitri Nestor Alice Van De Ville

We provide a new comparison between hexagonal and orthogonal lattices, based on approximation theory. For each of the lattices, we select the “natural” spline basis function as generator for a shift-invariant function space; i.e., the tensor-product B-spli ...

IEEE2005

Algebraic methods for channel coding

Frédérique Oggier

This work is dedicated to developing algebraic methods for channel coding. Its goal is to show that in different contexts, namely single-antenna Rayleigh fading channels, coherent and non-coherent MIMO channels, algebraic techniques can provide useful tool ...

EPFL2005

Réseaux idéaux sur des corps CM et des corps totalement réels

Ivan Suarez Atias

This thesis deals with the study of ideal lattices over number fields. Let K be a number field, which is assumed to be CM or totally real. An ideal lattice over K is a pair (I,b), where I is a fractional ideal of K and b : I × I → R is a symmetric positive ...

EPFL2005

Ab initio molecular dynamics simulation of redox reactions of transition metal ions in aqueous solution and proteins

Ivano Tavernelli

Redox potentials measure the free energy required to transfer a mol. species (ion) between two states of different total charge. In soln. a major contribution to the redox potential is the hydration free energy difference of the ion in the two oxidn. state ...

2005