Month: July 2017

An enhanced L-Shaped method for optimizing periodic-review inventory control problems modeled via two-stage stochastic programming

  • Fabricio Oliveira
  • Felipe Placido
    • Categories Production and Logistics, Stochastic Programming

    This paper presents the development of an enhanced L-Shaped method applied to an inventory management problem that considers a replenishment control system based on the periodic review (R,S) policy. We consider single-item one-echelon problems with uncertain demands and partial backorder that are modeled using two-stage stochastic programming. To enable the consideration of large-scale problems, the … Read more

    Invex Optimization Revisited

  • Ksenia Bestuzheva
  • Hassan L. Hijazi
    • Categories Applications - Science and Engineering, Global Optimization Theory, Nonlinear Optimization Tags , , ,

    Given a non-convex optimization problem, we study conditions under which every Karush-Kuhn-Tucker (KKT) point is a global optimizer. This property is known as KT-invexity and allows to identify the subset of problems where an interior point method always converges to a global optimizer. In this work, we provide necessary conditions for KT-invexity in n-dimensions and … Read more

    A simplex method for uncapacitated pure-supply infinite network flow problems

  • Marina A. Epelman
  • Christopher Thomas Ryan
  • Robert L. Smith
    • Categories Infinite Dimensional Optimization, Network Optimization Tags , ,

    We provide a simplex algorithm for a structured class of uncapacitated countably-infinite network flow problems. Previous efforts required explicit capacities on arcs with uniformity properties that facilitate duality arguments. By contrast, this paper takes a “primal” approach by devising a simplex method that provably converges to optimal value using arguments based on convergence of spanning … Read more

    Inexact cuts for Deterministic and Stochastic Dual Dynamic Programming applied to convex nonlinear optimization problems

  • Vincent Guigues
    • Categories Convex Optimization, Dynamic Programming, Stochastic Programming

    We introduce an extension of Dual Dynamic Programming (DDP) to solve convex nonlinear dynamic programming equations. We call Inexact DDP (IDDP) this extension which applies to situations where some or all primal and dual subproblems to be solved along the iterations of the method are solved with a bounded error. We show that any accumulation … Read more

    A rounding procedure for semidefinite optimization

  • Ali Mohammad-Nezhad
  • Tamás Terlaky
    • Categories Semi-definite Programming Tags , , ,

    Recently, Mohammad-Nezhad and Terlaky studied the identification of the optimal partition for semidefinite optimization. An approximation of the optimal partition was obtained from a bounded sequence of solutions on, or in a neighborhood of the central path. Here, we use the approximation of the optimal partition in a rounding procedure to generate an approximate maximally … Read more