Concept

Projection de Postel

Publications associées (11)

Three-dimensional tomography of red blood cells using deep learning

Demetri Psaltis, Joowon Lim, Ahmed Ayoub

We accurately reconstruct three-dimensional (3-D) refractive index (RI) distributions from highly ill-posed two-dimensional (2-D) measurements using a deep neural network (DNN). Strong distortions are introduced on reconstructions obtained by the Wolf tran ...

2020

Convergences of Regularized Algorithms and Stochastic Gradient Methods with Random Projections

Volkan Cevher, Junhong Lin

We study the least-squares regression problem over a Hilbert space, covering nonparametric regression over a reproducing kernel Hilbert space as a special case. We rst investigate regularized algorithms adapted to a projection operator on a closed subspace ...

2020

Fast multiscale reconstruction for Cryo-EM

Michaël Unser, Laurène Donati, Masih Nilchian

We present a multiscale reconstruction framework for single-particle analysis (SPA). The representation of three-dimensional (3D) objects with scaled basis functions permits the reconstruction of volumes at any desired scale in the real-space. This multisc ...

Elsevier2018

Exterior Convexity And Classical Calculus Of Variations

Saugata Bandyopadhyay, Swarnendu Sil

We study the relation between various notions of exterior convexity introduced in [S. Bandyopadhyay, B. Dacorogna and S. Sil, J. Eur. Math. Soc. 17 (2015) 1009-1039.] with the classical notions of rank one convexity, quasiconvexity and polyconvexity. To th ...

Edp Sciences S A2016

Shape-Up: Shaping Discrete Geometry with Projections

Mark Pauly, Sofien Bouaziz, Yuliy Gennadievich Schwartzburg, Mario Moacir Deuss

We introduce a uniﬁed optimization framework for geometry processing based on shape constraints. These constraints preserve or prescribe the shape of subsets of the points of a geometric data set, such as polygons, one-ring cells, volume elements, or featu ...

Wiley-Blackwell2012

Compressed sensing for wide-field radio interferometric imaging

Yves Wiaux, Jason Douglas McEwen

For the next generation of radio interferometric telescopes it is of paramount importance to incorporate wide field-of-view (WFOV) considerations in interferometric imaging, otherwise the fidelity of reconstructed images will suffer greatly. We extend comp ...

OUP2011

Sparse Approximations Of Protein Structure From Noisy Random Projections

Victor Panaretos, Kjell Konis

Single-particle electron microscopy is a modern technique that biophysicists employ to learn the structure of proteins. It yields data that consist of noisy random projections of the protein structure in random directions, with the added complication that ...

2011

Comparison of measured and simulated fast ion velocity distributions in the TEXTOR tokamak

Mattia Albergante, Otto Asunta

Here we demonstrate a comprehensive comparison of collective Thomson scattering (CTS) measurements with steady-state Monte Carlo simulations performed with the ASCOT and VENUS codes. The measurements were taken at a location on the magnetic axis as well as ...

2011

Wavelet transform on manifolds: old and new approaches

Pierre Vandergheynst

Given a two-dimensional smooth manifold M and a bijective pro jection p from M on a ﬁxed plane (or a subset of that plane), we explore systematically how a wavelet transform (WT) on M may be generated from a plane WT by the inverse projection. Examples whe ...

Elsevier2010

Grazing function g and collimation angular acceptance

Valentina Previtali

The grazing function g is introduced—a synchrobetatron optical quantity that is analogous (and closely connected) to the Twiss and dispersion functions β, α, η, and η′. It parametrizes the rate of change of total angle with respect to synchrotron amplitude ...

American Physical Society2009

Consistent Sampling and Signal Recovery

Michaël Unser

An attractive formulation of the sampling problem is based on the principle of a consistent signal reconstruction. The requirement is that the reconstructed signal is indistinguishable from the input in the sense that it yields the exact same measurements. ...

Institute of Electrical and Electronics Engineers2007