Ahmed Saif

Worst-Case Conditional Value at Risk for Asset Liability Management: A Novel Framework for General Loss Functions

  • Alireza Ghahtarani
  • Ahmed Saif
  • Alireza Ghasemi
    • Categories Applications - OR and Management Sciences, Finance and Economics, Robust Optimization Tags , , , ,

    Asset-liability management (ALM) is a challenging task faced by pension funds due to the uncertain nature of future asset returns and interest rates. To address this challenge, this paper presents a new mathematical model that uses aWorst-case Conditional Value-at-Risk (WCVaR) constraint to ensure that the funding ratio remains above a regulator-mandated threshold with a high … Read more

    A Double-oracle, Logic-based Benders decomposition approach to solve the K-adaptability problem

  • Alireza Ghahtarani
  • Ahmed Saif
  • Alireza Ghasemi
  • Erick Delage
    • Categories Combinatorial Optimization, Robust Optimization Tags , , , ,

    We propose a novel approach to solve K-adaptability problems with convex objective and constraints and integer first-stage decisions. A logic-based Benders decomposition is applied to handle the first-stage decisions in a master problem, thus the sub-problem becomes a min-max-min robust combinatorial optimization problem that is solved via a double-oracle algorithm that iteratively generates adverse scenarios … Read more

    Robust Portfolio Selection Problems: A Comprehensive Review

  • Alireza Ghahtarani
  • Ahmed Saif
  • Alireza Ghasemi
    • Categories Applications - OR and Management Sciences, Finance and Economics, Robust Optimization Tags ,

    In this paper, we provide a comprehensive review of recent advances in robust portfolio selection problems and their extensions, from both operational research and financial perspectives. A multi-dimensional classification of the models and methods proposed in the literature is presented, based on the types of financial problems, uncertainty sets, robust optimization approaches, and mathematical formulations. … Read more

    The Value of Randomized Solutions in Mixed-Integer Distributionally Robust Optimization Problems

  • Erick Delage
  • Ahmed Saif
    • Categories (Mixed) Integer Linear Programming, Robust Optimization Tags , ,

    Randomization refers to the process of taking decisions randomly according to the outcome of an independent randomization device such as a dice or a coin flip. The concept is unconventional, and somehow counterintuitive, in the domain of mathematical programming, where deterministic decisions are usually sought even when the problem parameters are uncertain. However, it has … Read more