7,609 research outputs found
A single cut proximal bundle method for stochastic convex composite optimization
In this paper, we consider optimization problems where the objective is the
sum of a function given by an expectation and a Lipschitz continuous convex
function. For such problems, we propose a Stochastic Composite Proximal Bundle
(SCPB) method with optimal complexity. The method does not require estimation
of parameters involved in the assumptions on the objective functions. Moreover,
to the best of our knowledge, this is the first proximal bundle method for
stochastic programming able to deal with continuous distributions. Finally, we
present the results of numerical experiments where SCPB slightly outperforms
Stochastic Mirror Descent.Comment: 23 page
Extended field-of-view in a lensless endoscope using an aperiodic multicore fiber
We investigate lensless endoscopy using coherent beam combining and aperiodic
multicore fibers (MCF). We show that diffracted orders, inherent to MCF with
periodically arranged cores, dramatically reduce the field of view (FoV) and
that randomness in MCF core positions can increase the FoV up to the
diffraction limit set by a single fiber core, while maintaining MCF
experimental feasibility. We demonstrate experimentally pixelation-free
lensless endoscopy imaging over a 120 micron FoV with an aperiodic MCF designed
with widely spaced cores. We show that this system is suitable to perform beam
scanning imaging by simply applying a tilt to the proximal wavefront.Comment: Submitted to Optics Letter
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