Publications associées à Spherical conic

On the Maximum Power Density of Implanted Antennas within Simplified Body Phantoms

Anja Skrivervik, Mingxiang Gao, Zvonimir Sipus

With the application requirements of wireless technology in implantable bioelectronics, knowledge of the fundamental limits for implanted antennas becomes critical. In this work, we investigated the variation of maximum power density within simplified body ...

IEEE2022

Graph-based regularization of inverse problems in imaging

Mattia Rossi

As of today, the extension of the human visual capabilities to machines remains both a cornerstone and an open challenge in the attempt to develop intelligent systems. On the one hand, the development of more and more sophisticated imaging devices, capable ...

EPFL2020

A Weak Form Implementation of Nonlinear Axisymmetric Shell Equations With Examples

Pedro Miguel Nunes Pereira de Almeida Reis, Matteo Pezzulla

We present a weak form implementation of the nonlinear axisymmetric shell equations. This implementation is suitable to study the nonlinear deformations of axisymmetric shells, with the capability of considering a general mid-surface shape, non-homogeneous ...

2019

Specification of aspherical surfaces used as refractive elements in micro-optical systems

Toralf Scharf, Wilfried Noell, Jeremy Béguelin

The optical performance of refractive plano-convex microlenses is mainly related to the quality of their (a)spherical surface. An efficient tolerancing of this surface is a key step towards the manufacturing of high quality microlenses. However, we demonst ...

SPIE-INT SOC OPTICAL ENGINEERING2019

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

Building a Casimir metrology platform with a commercial MEMS sensor

Matthias Imboden

The Casimir Effect is a physical manifestation of quantum fluctuations of the electromagnetic vacuum. When two metal plates are placed close together, typically much less than a micron, the long wavelength modes between them are frozen out, giving rise to ...

Springer2019

Geometry Aware Convolutional Filters for Omnidirectional Images Representation

Pascal Frossard, Renata Khasanova

Due to their wide field of view, omnidirectional cameras are frequently used by autonomous vehicles, drones and robots for navigation and other computer vision tasks. The images captured by such cameras, are often analyzed and classified with techniques de ...

2019

Graph-Based Detection of Seams In 360-Degree Images

Pascal Frossard, Francesca De Simone, Sohyeong Kim, Roberto Gerson De Albuquerque Azevedo

In this paper, we propose an algorithm to detect a specific kind of distortions, referred to as seams, which commonly occur when a 360-degree image is represented in planar domain by projecting the sphere to a polyhedron, e.g, via the Cube Map (CM) project ...

2019

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

Rate Distortion Optimized Graph Partitioning for Omnidirectional Image Coding

Pascal Frossard, Francesca De Simone, Thomas Maugey, Mira Rizkallah

Omnidirectional images are spherical signals captured by cameras with 360-degree field of view. In order to be compressed using existing encoders, these signals are mapped to planar domain. A commonly used planar representation is the equirectangular one, ...

IEEE COMPUTER SOC2018

An advanced methodology for the mix design optimization of hot mix asphalt

André-Gilles Dumont, Sara Bressi, Manfred Partl

The bitumen quantity to add to asphalt mixtures depends on the surfaces of aggregates and filler to be coated. The formulas currently available in the literature have limitations such as considering all the fillers with the same specific surface or the agg ...

Elsevier Sci Ltd2016

Reconfigurable Forward Homography Estimation System for Real-Time Applications

Yusuf Leblebici, Vladan Popovic

Image processing and computer vision algorithms extensively use projections, such as homography, as one of the processing steps. Systems for homography calculation usually observe homography as an inverse problem and provide an exact solution. However, the ...

2014

Light confinement effect of non-spherical nanoscale solid immersion lenses

Hans Peter Herzig, Toralf Scharf, Myun Sik Kim, Gaël David Osowiecki, David Nguyen

We report on the light confinement effect observed in non-ideally shaped (i.e., non-spherical) nanoscale solid immersion lenses (SILs). To investigate this effect, nanostructures of various shapes are fabricated by electron-beam lithography. When completel ...

Spie-Int Soc Optical Engineering2013

Dynamic Visual Attention on the Sphere

Pierre-André Farine, Iva Bogdanova Vandergheynst, Heinz Hügli, Alexandre Bur

In this paper we present a computational model of dynamic visual attention on the sphere which combines static (intensity,chromaticity, orientation) and motion features in order to detect salient locations in omnidirectional image sequences while working d ...

Elsevier2010

The microcontainer shape in electropolymerization on bubbles

Giorgio Margaritondo

We investigated the microcontainer shape in electropolymerization of polypyrrole (PPy) on bubbles using real-time microradiography. We revealed the existence of a "deformation force" at the three-phase boundary among gas (bubble), liquid (electrolyte), and ...

AIP American Institute of Physics2009

Low bit-rate compression of omnidirectional images

Pascal Frossard, Ivana Tosic

Omnidirectional images represent a special type of images that are captured by vision sensors with a 360-degree field of view. This work targets the compression of such images by taking into account their particular geometry. We first map omnidirectional i ...

2009

The continuous wavelet transform on conic sections

Pierre Vandergheynst, Iva Bogdanova Vandergheynst

We review the known construction of the continuous wavelet transform (CWT) on the two-sphere. Next we describe the construction of a CWT on the upper sheet of a two- sheeted hyperboloid, emphasizing the similarities between the two cases. Finally we give s ...

2008

Spherical pore replicated Microcellular Aluminium

Andreas Mortensen

A method is presented that extends the replication process for the manufacture of open-celled metallic foams to include foams with spherical cells. Such foams are produced to a wide range of relative densities, tested for mechanical behaviour and resistanc ...

Japan Institute of Metals, Sendai, Japan2007

Wavelets on the two-sphere and other conic sections

Pierre Vandergheynst

We review the construction of the continuous wavelet transform (CWT) on the two-sphere by two methods, the group-theoretical approach and the geometrical method based on conformal invariance. Then we discuss the discretization of the spherical CWT, obtaini ...

2007

On the behavior of spherical and non-spherical grain assemblies, its modeling and numerical simulation

Lionel Pournin

This thesis deals with the numerical modeling and simulation of granular media with large populations of non-spherical particles. Granular media are highly pervasive in nature and play an important role in technology. They are present in fields as diverse ...

EPFL2005