Publications related to Radius of curvature

Indentation and stability of woven domes

Pedro Miguel Nunes Pereira de Almeida Reis, Célestin Vallat, Tian Chen, Tomohiko Sano, Samuel Jean Bernard Poincloux

Discrete domes are doubly curved structures comprising a network of beam-like elements. We study the mechanics of discrete domes made of ribbons woven in a pentagonal triaxial pattern. Experiments and finite element simulations are performed to characteriz ...

ELSEVIER2023

Nonperturbative Quantum Field Theory in Curved Spacetime

Kamran Salehi Vaziri

Quantum Field Theory(QFT) as one of the most promising frameworks to study high energy and condensed matter physics, has been mostly developed by perturbative methods. However, perturbative methods can only capture a small island of the space of QFTs. QFT ...

EPFL2022

GarNet++: Improving Fast and Accurate Static 3D Cloth Draping by Curvature Loss

Pascal Fua, Mathieu Salzmann, Victor Constantin, Shaifali Parashar, Erhan Gündogdu

In this paper, we tackle the problem of static 3D cloth draping on virtual human bodies. We introduce a two-stream deep network model that produces a visually plausible draping of a template cloth on virtual 3D bodies by extracting features from both the b ...

2022

Nonlinear buckling behavior of a complete spherical shell under uniform external pressure and homogenous natural curvature

Matteo Pezzulla

In this work, we consider the stability of a spherical shell under combined loading from a uniform external pressure and a homogenous natural curvature. Nonmechanical stimuli, such as one that tends to modify the rest curvature of an elastic body, are prev ...

AMER PHYSICAL SOC2020

Tribological Approach to the Watch Movements

Valentine Agnès Madeleine Magnin

Mechanical watches are complex and sensitive systems that have to maintain a faultless precision over their lifetime. However, this precision can be altered by disturbances occurring during the functioning time, such as friction, lubricant drying, or wear, ...

EPFL2020

Robustness via curvature regularization, and vice versa

Pascal Frossard, Seyed Mohsen Moosavi Dezfooli, Alhussein Fawzi

State-of-the-art classifiers have been shown to be largely vulnerable to adversarial perturbations. One of the most effective strategies to improve robustness is adversarial training. In this paper, we investigate the effect of adversarial training on the ...

IEEE2019

Buckling of geometrically confined shells

Matteo Pezzulla

We study the periodic buckling patterns that emerge when elastic shells are subjected to geometric confinement. Residual swelling provides access to range of shapes (saddles, rolled sheets, cylinders, and spherical sections) which vary in their extrinsic a ...

ROYAL SOC CHEMISTRY2019

Chemically etched plastic optical fiber probe for near-field scanning optical microscopy in liquids

Giovanni Dietler, Serguei Sekatski, Anton Smirnov, Kanat Dukenbayev

Some preliminary results and experimental details of Near-field Scanning Optical Microscopy (NSOM) operation in liquids have been reported by us earlier(1-4). Here we present the first use of custom made polystyrene/poly (methyl methacrylate) (PMMA) optica ...

SPIE-INT SOC OPTICAL ENGINEERING2019

Improved calibration of vertical scanning optical profilometers for spherical profiles measurements

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

A new method for calibrating optical scanning profilometers is presented. Especially adapted to spherical and aspherical profile measurements, it shows an increase of accuracy bigger than one order of magnitude for radius of curvature measurements. Calibra ...

2018

Numerical Modelling of Two-Phase Flow with Moving Boundary Fitted Meshes

Erik Gros

In this thesis, a computational approach is used to study two-phase flow including phase change by direct numerical simulation. This approach follows the interface with an adaptive moving mesh. The incompressible Navier-Stokes equations are solved, in tw ...

EPFL2018

Out-of-plane instability of thin reinforced concrete walls under seismic loading

Angelica Rosso

Out of plane instability of reinforced concrete walls is a failure mechanism observed rather recently following the earthquakes in Chile (2010) and New Zealand (2011). Global out of plane instability is a phenomenon that may occur in thin walls, subjected ...

EPFL2018

Axially equilibrated displacement-based beam element for simulating the cyclic inelastic behaviour of RC members

Katrin Beyer, João Saraiva Esteves Pacheco de Almeida, Danilo Tarquini

Distributed plasticity beam elements are commonly used to evaluate limit state demands for performance based analysis of reinforced concrete (RC) structures. Strain limits are often preferred to drift limits since they directly relate to damage and are the ...

2017

Bend translation in multimode fiber imaging

Demetri Psaltis, Christophe Moser, Damien Claude-Marie Loterie

Light propagation in multimode fibers is typically assumed to be extremely sensitive to changes in geometry. We study here a particular configuration where an S-shaped bend is translated between two sections of fiber. In this sliding bend configuration, we ...

Optical Soc Amer2017

Isogeometric Analysis for High Order Geometric Partial Differential Equations with Applications

Andrea Bartezzaghi

In this thesis, we consider the numerical approximation of high order geometric Partial Differential Equations (PDEs). We first consider high order PDEs defined on surfaces in the 3D space that are represented by single-patch tensor product NURBS. Then, we ...

EPFL2017

Optimal Approximation for Submodular and Supermodular Optimization with Bounded Curvature

Justin Dean Ward

We design new approximation algorithms for the problems of optimizing submodular and supermodular functions subject to a single matroid constraint. Specifically, we consider the case in which we wish to maximize a monotone increasing submodular function or ...

INFORMS2017

A parametrical study on secondary flow in sharp open-channel bends: experiments and theoretical modelling

Anton Schleiss, Koen Blanckaert, Joris Heyman

The dependence of curvature-induced secondary flow on the curvature ratio H/R (H is the average flow depth and R is the centreline radius of curvature), the Froude number Fr, and the dimensionless roughness coefficient Cf was systematically investigated in ...

Elsevier Science Bv2016

Medial axis transformation as a solid modeling representation method for computer aided design software

Paul Xirouchakis, Ian Anthony Stroud, Mihai-Bogdan Lazar, Florian Barras, Guillaume Goualard

A method for achieving a representation of an object within a data structure for a Computer Aided Design system employing a Medial Axis Transformation (MAT), the representation of the object comprising a set of adjacent bounded surface elements called MAT ...

2016

Experiments of flow separation at the inner bank of open-channel bends

Anton Schleiss, Koen Blanckaert, Joris Heyman

In spite of its hydraulic and morphologic importance, the conditions of occurrence of flow separation at the inner bank of open channel bends are still not known. In a series of 23 experiments in a laboratory open channel bend with flat sand bed, it was in ...

2015

Overview of the Geometries of Shape Spaces and Diffeomorphism Groups

Martins Bruveris, Martin Bauer

This article provides an overview of various notions of shape spaces, including the space of parametrized and unparametrized curves, the space of immersions, the diffeomorphism group and the space of Riemannian metrics. We discuss the Riemannian metrics th ...

Springer Verlag2014

Planck 2013 results. XXVI. Background geometry and topology of the Universe

Julien Lesgourgues, Jason Douglas McEwen, Fabio Finelli

The new cosmic microwave background (CMB) temperature maps from Planck provide the highest-quality full-sky view of the surface of last scattering available to date. This allows us to detect possible departures from the standard model of a globally homogen ...

Edp Sciences S A2014