Publications associées à Development and integration of high straightness flexure guiding mechanisms dedicated to the METAS watt balance Mark II

Rectilinear translation four-bar flexure mechanism based on four Remote Center Compliance pivots

Simon Nessim Henein, Charles Baur, Loïc Benoît Tissot-Daguette, Hubert Pierre-Marie Benoît Schneegans, Quentin Gubler

This paper presents a novel planar four-bar linkage compliant mechanism (called 4-RCC) based on four flexure-based Remote Center of Compliance (RCC) pivots. With particular configurations and dimensions, the beam shortening of the RCC pivots can compensate ...

euspen2022

A new regret analysis for Adam-type algorithms

Volkan Cevher, Ahmet Alacaoglu

In this paper, we focus on a theory-practice gap for Adam and its variants (AMSgrad, AdamNC, etc.). In practice, these algorithms are used with a constant first-order moment parameter 1 (typically between 0:9 and 0:99). In theory, regret guarantees for onl ...

JMLR-JOURNAL MACHINE LEARNING RESEARCH2020

Cost for a controlled linear KdV equation

Joachim Krieger, Shengquan Xiang

The controllability of the linearized KdV equation with right Neumann control is studied in the pioneering work of Rosier [25]. However, the proof is by contradiction arguments and the value of the observability constant remains unknown, though rich mathem ...

2019

Depth-averaged momentum equation for gravity currents with varying density: coefficient in pressure term

Mário Jorge Rodrigues Pereira Da Franca, Sara Venuleo

Gravity currents are often modelled by means of shallow water equations (SWEs). In these models, simplifications such as the consideration of a constant layer-averaged density are common. This note presents the complete and general derivation of a 2D depth ...

Taylor & Francis Ltd2018

Liquid CO2 processing of solid polylactide foam precursors

John Christopher Plummer, Yonghoon Yoon

Diffusion of CO2 in polylactide was modelled by assuming the diffusion coefficient to depend on CO2 concentration, c, according to D[c]=D[0]exp[Ac], where D[0] and A are empirical constants, with the aim of optimizing impregnation of nominally amorphous an ...

Sage Publications Ltd2016

Heat expandable biopolymers for one-step production of foam core sandwich composites

Yonghoon Yoon

The overall aim of this work has been to develop sustainable solid thermally activated foam precursors suitable for the in-line production of lightweight bio-based foam core sandwich structures with consolidated wood particle facings, using a non-inflammab ...

EPFL2016

Design, analysis, testing and applications of two-body and three-body kinematic mounts

Johannes Richard Cornelis Geerit Kruis

Kinematic couplings are used when two rigid bodies need to be repeatedly and accurately positioned with respect to each other. They allow for sub-micron positioning repeatability by suppressing play and reducing strains in the bodies. Typical applications ...

EPFL2016

Planck intermediate results XXIV. Constraints on variations in fundamental constants

Julien Lesgourgues, Fabio Finelli

Any variation in the fundamental physical constants, more particularly in the fine structure constant, a, or in the mass of the electron, me, affects the recombination history of the Universe and cause an imprint on the cosmic microwave background angular ...

EDP Sciences2015

Timescales of N-H bond dissociation in pyrrole: a nonadiabatic dynamics study

Antonio Prlj, Momir Malis

The excitation wavelength dependent photodynamics of pyrrole are investigated by nonadiabatic trajectory-surface-hopping dynamics simulations based on time dependent density functional theory (TDDFT) and the algebraic diagrammatic construction method to th ...

Royal Soc Chemistry2015

The second order pullback equation

Bernard Dacorogna, Olivier Kneuss, Gyula Csató

Let f, g be two closed k-forms over R-n. The pullback equation studies the existence of a diffeomorphism phi : R-n -> R-n such that phi*(g) = f. We prove two types of results. The first one sharpens some of the existing regularity results. The second one d ...

Springer2014

Design of the new METAS watt balance experiment Mark II

Reymond Clavel, Florent Cosandier

The kilogram is the last unit of the international system of units (SI) still based on a material artefact, the international prototype of the kilogram (IPK). The comparisons made in the last hundred years have clearly revealed a long-term relative drift b ...

Iop Publishing Ltd2013

Dynamics of the head of gravity currents

Mário Jorge Rodrigues Pereira Da Franca, Helena Isabel Dos Santos Nogueira, Claudia Adduce

The present work experimentally investigates the dynamics of unsteady gravity currents produced by lock-release of a saline mixture into a fresh water tank. Seven different experimental runs were performed by varying the density of the salinemixture in the ...

Springer Verlag2013

Scale-invariant alternatives to general relativity

Mikhail Chapochnikov, Daniel Zenhäusern, Diego Blas Temino

We study the general class of gravitational field theories constructed on the basis of scale invariance (and therefore absence of any mass parameters) and invariance under transverse diffeomorphisms, which are the 4-volume conserving coordinate transformat ...

American Physical Society2011

Scale-Invariant Models of Gravity and Particle Physics and their Cosmological Implications

Daniel Zenhäusern

Currently, the best theoretical description of fundamental matter and its gravitational interaction is given by the Standard Model (SM) of particle physics and Einstein's theory of General Relativity (GR). These theories contain a number of seemingly unrel ...

EPFL2011

Design of hybrid-kinematic mechanisms for machine tools

Patric Pham

The machine tool industry is a well established, old and extremely important branch of today's manufacturing industry. With the ongoing globalization and the resulting increase of competition in this industry, the manufacturers have to push their technolog ...

EPFL2009

The influence of frequency dependent soil electrical parameters on the evaluation of lightning electromagnetic fields in air and underground

Farhad Rachidi-Haeri

This paper is aimed at analyzing the influence of the frequency-dependent behavior of the ground electrical parameters ( conductivity and ground permittivity) on the electromagnetic field radiated by a cloud-to-ground lightning return stroke. Both radiatio ...

2009

Illuminant retrieval for fixed location cameras

Joanna Marguier, Sabine Süsstrunk

Fixed location cameras, such as panoramic cameras or surveillance cameras, are very common. In images taken with these cameras, there will be changes in lighting and dynamic image content, but there will also be constant objects in the background. We propo ...

2008

The surface Laplacian operator of the potentials on a bounded volume conductor has a unique inverse

In the discussion on the use of the surface Laplacian (SL) of the distribution of bioelectric potentials on the body surface, the question remained open whether a complete specification of the SL of the potential over the surface bounding a volume conducto ...

2006

Measurement of the running of the electromagnetic coupling at large momentum-transfer at LEP

Eduardo Sanchez, Horst Vogel, Aurelio Bay, Jian Zhao, Liang Sun, Qian Wang, Zhirui Xu, Matthias Weber, Ji Hyun Kim, Werner Lustermann, Xiao Wang, Zheng Wang

The evolution of the electromagnetic coupling, α, in the momentum-transfer range 1800 GeV2 < -Q2 < 21600 GeV2 is studied with about 40 000 Bhabha-scattering events collected with the L3 detector at LEP at centre-of-mass energies √s = 189-209 GeV. The runni ...

2005

Gravitating field-theoretical branes and their excitations

Katarzyna Zuleta Estrugo

This thesis is devoted to studying field-theoretical branes in warped geometries, with emphasis on brane excitations and properties of background solutions. Firstly, we examine the features of a model in which our universe is represented by a local string- ...

EPFL2005