This work studies multi-agent sharing optimization problems with the objective function being the sum of smooth local functions plus a convex (possibly non-smooth) function coupling all agents. This scenario arises in many machine learning and engineering ...

IEEE2020

Property FW, differentiable structures and smoothability of singular actions

Yash Lodha, Nicolas Matte Bon

We provide a smoothening criterion for group actions on manifolds by singular diffeomorphisms. We prove that if a countable group Gamma has the fixed point property FW for walls (for example, if it has property(T)), every aperiodic action of Gamma by diffe ...

WILEY2020

Active control for mid-span connection of a deployable tensegrity footbridge

Ian Smith, Nicolas Willy Veuve, Seif Dalil Safaei

Tensegrity structures are spatial self-stressed pin jointed structures where compression components (struts) are surrounded by tension elements. This paper describes a near full-scale deployable tensegrity footbridge that deploys from both sides and connec ...

2016

A comment on the construction of the maximal globally hyperbolic Cauchy development

Willie Wai Yeung Wong

Under mild assumptions, we remove all traces of the axiom of choice from the construction of the maximal globally hyperbolic Cauchy development in general relativity. The construction relies on the notion of direct union manifolds, which we review. The con ...

American Institute of Physics2013

Modular DC/DC Converter: Comparison of Modulation Methods

Alfred Rufer, Drazen Dujic, Stephan Kenzelmann

This paper presents a bidirectional modular DC/DC converter. It consists of two Modular Multilevel Converters (MMC) linked by a transformer to achieve galvanic isolation. This topology serves as “DC transformer” interfacing low and medium voltage DC grids. ...

2012

A Primal-Dual Reconstruction Algorithm For Fluorescence And Bioluminescence Tomography

Michaël Unser, Jean-Charles Baritaux

We introduce a new primal-dual reconstruction algorithm for fluorescence and bioluminescence tomography. As often in optical tomography, image reconstruction is performed by optimizing a multi-term convex cost function. Current reconstruction methods emplo ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

A first-order primal-dual method with adaptivity to local smoothness

Volkan Cevher, Maria-Luiza Vladarean

We consider the problem of finding a saddle point for the convex-concave objective

\min_x \max_y f(x) + \langle Ax, y\rangle - g^*(y)

, where

f

is a convex function with locally Lipschitz gradient and

g

is convex and possibly non-smooth. We propose an ...

2021

A stability theory beyond the co-rotational setting for critical wave maps blow up

Joachim Krieger, Shuang Miao

We exhibit non-equivariant perturbations of the blowup solutions constructed in [18] for energy critical wave maps into

\mathbb{S}^2

. Our admissible class of perturbations is an open set in some sufficiently smooth topology and vanishes near the light co ...

2020