Spectral properties of Barzilai-Borwein rules in solving singly linearly constrained optimization problems subject to lower and upper bounds

  • Serena Crisci
  • Federica Porta
  • Luca Zanni
  • Valeria Ruggiero
    • Categories Constrained Nonlinear Optimization, Nonlinear Optimization Tags , , ,

    In 1988, Barzilai and Borwein published a pioneering paper which opened the way to inexpensively accelerate first-order methods. More in detail, in the framework of unconstrained optimization, Barzilai and Borwein developed two strategies to select the steplength in gradient descent methods with the aim of encoding some second-order information of the problem without computing and/or … Read more

    Computational Simulation as an organizational prototyping tool

  • Clio Dosi
  • Manuel Iori
  • Arthur Kramer
  • Matteo Vignoli
    • Categories Applications - OR and Management Sciences, Applications - Science and Engineering Tags

    This case study deals with a redesign effort to face the overcrowding issue in an Emergency Department (ED). A multidiscinary group of healthcare professionals and engineers worked together to improve the actual processes. We integrate the simulation modeling in a humancentered design method. We use the simulation technique as a learning and experimentation tool into … Read more

    On the Complexity of an Augmented Lagrangian Method for Nonconvex Optimization

  • Geovani Nunes Grapiglia
  • Ya-xiang Yuan
    • Categories Nonlinear Optimization Tags , , ,

    In this paper we study the worst-case complexity of an inexact Augmented Lagrangian method for nonconvex constrained problems. Assuming that the penalty parameters are bounded, we prove a complexity bound of $\mathcal{O}(|\log(\epsilon)|)$ outer iterations for the referred algorithm to generate an $\epsilon$-approximate KKT point, for $\epsilon\in (0,1)$. When the penalty parameters are unbounded, we prove … Read more

    Portfolio Optimization with Irreversible Long-Term Investments in Renewable Energy under Policy Risk: A Mixed-Integer Multistage Stochastic Model and a Moving-Horizon Approach

  • Nadine Gatzert
  • Martin Schmidt
  • Alexander Martin
  • Benjamin Seith
  • Nikolai Vogl
    • Categories (Mixed) Integer Linear Programming, Applications - OR and Management Sciences, Stochastic Programming Tags , , , ,

    Portfolio optimization is an ongoing hot topic of mathematical optimization and management science. Due to the current financial market environment with low interest rates and volatile stock markets, it is getting more and more important to extend portfolio optimization models by other types of investments than classical assets. In this paper, we present a mixed-integer … Read more

    Benders Cut Classification via Support Vector Machines for Solving Two-stage Stochastic Programs

  • Huiwen Jia
  • Siqian Shen
    • Categories Cutting Plane Approaches, Stochastic Programming Tags , , ,

    We consider Benders decomposition for solving two-stage stochastic programs with complete recourse based on finite samples of the uncertain parameters. We define the Benders cuts binding at the final optimal solution or the ones significantly improving bounds over iterations as valuable cuts. We propose a learning-enhanced Benders decomposition (LearnBD) algorithm, which adds a cut classification … Read more

    Distributionally Robust Partially Observable Markov Decision Process with Moment-based Ambiguity

  • Ruiwei Jiang
  • Siqian Shen
  • Hideaki Nakao
    • Categories Dynamic Programming, Robust Optimization Tags , , , ,

    We consider a distributionally robust Partially Observable Markov Decision Process (DR-POMDP), where the distribution of the transition-observation probabilities is unknown at the beginning of each decision period, but their realizations can be inferred using side information at the end of each period after an action being taken. We build an ambiguity set of the joint … Read more

    Strategic Network Design for Parcel Delivery with Drones under Competition

  • Gohram Baloch
  • Fatma Gzara
    • Categories (Mixed) Integer Nonlinear Programming, Supply Chain Management, Transportation

    This paper studies the economic desirability of UAV parcel delivery and its e ect on e-retailer distribution network while taking into account technological limitations, government regulations, and customer behavior. We consider an e-retailer o ering multiple same day delivery services including a fast UAV service and develop a distribution network design formulation under service based competition where … Read more

    Generalized Chvatal-Gomory closures for integer programs with bounds on variables

  • Sanjeeb Dash
  • Oktay Gunluk
  • Dabeen Lee
    • Categories (Mixed) Integer Linear Programming, Cutting Plane Approaches Tags , , ,

    Integer programming problems that arise in practice often involve decision variables with one or two sided bounds. In this paper, we consider a generalization of Chvatal-Gomory inequalities obtained by strengthening Chvatal-Gomory inequalities using the bounds on the variables. We prove that the closure of a rational polyhedron obtained after applying the generalized Chvatal-Gomory inequalities is … Read more

    Adaptive Two-stage Stochastic Programming with an Application to Capacity Expansion Planning

  • Shabbir Ahmed
  • Nagi Gebraeel
  • Beste Basciftci
    • Categories Applications - OR and Management Sciences, Stochastic Programming Tags , , , , ,

    Multi-stage stochastic programming is a well-established framework for sequential decision making under uncertainty by seeking policies that are fully adapted to the uncertainty. Often, e.g. due to contractual constraints, such flexible and adaptive policies are not desirable, and the decision maker may need to commit to a set of actions for a certain number of … Read more

    Assessment of Climate Agreements over the Long Term with Strategic Carbon Dioxyde Removal Activity

  • Frédéric Babonneau
  • Alain Haurie
  • Alain Vielle
    • Categories Applications - OR and Management Sciences, Game Theory Tags , , , ,

    In this paper we extend a game theoretic meta-model used to assess the future of Paris agreement to the time horizon 2100 and we include in the strategic decisions of the negotiating coalitions the use of Carbon Dioxyde Removal (CDR) technologies. The meta-game model is calibrated through statistical emulation of GEMINI-E3, a world computable general … Read more