Title: Problem Decomposition in Optimization:聽 Algorithmic Advances Beyond ADMM
Speaker: | R. Tyrell Rockafellar |
Affiliation: | The University of Washington |
Location: | Main Hall, Federation Hall |
Abstract:
Decomposition schemes like those coming from ADMM typically start by posing a separable-type problem in the Fenchel duality format.聽 They then pass to an augmented Lagrangian, which however can interfere with the separability and cause a slow-down.聽 Progressive decoupling offers a more flexible approach which can utilize augmented Lagrangians while maintaining decomposability.聽 Based on a variable metric extension of the proximal point algorithm that's applied in a twisted sort of way, progressive decoupling benefits from stopping criteria which can guarantee convergence despite inexact minimization in each iteration.聽 聽The convergence is generically at a linear rate, and for convex problems, is global. But the method also works for nonconvex problems when initiated close enough to a point that satisfies a natural extension of the strong sufficient condition for local optimality known from nonlinear programming.
This talk is held as part of the 26th Annual Midwest Optimization Meeting (鈥淢OM26鈥).