Applications – Science and Engineering

Collection points placement in urban delivery: A game-theoretic analysis of public and competitive strategies

  • Fabio Mercurio
  • Margarida Carvalho
  • S.U.K Rohmer
  • Loe Schlicher
  • Tom Van Woensel
    • Categories Facility Planning and Design, Game Theory Tags , , , ,

    Collection point networks are rapidly expanding as delivery companies and public authorities promote their implementation to consolidate deliveries and reduce urban congestion. However, rather than catering to public interest by maximizing accessibility, the placement of collection points remains primarily driven by competition among delivery companies, which seek to maximize their market share. This paper thus … Read more

    Constrained Enumeration of Lucky Tickets: Prime Digits, Uniqueness, and Greedy Heuristics

  • Bismark Singh
    • Categories Basic Sciences Applications, Optimization in Data Science

    We revisit the classical Lucky Ticket (LT) enumeration problem, in which an even-digit number is called lucky if the sum of the digits of its first half equals to that of its second half. We introduce two new subclasses — SuperLucky Tickets (SLTs), where all digits are distinct, and LuckyPrime Tickets (LPTs), where all digits … Read more

    Preconditioning for rational approximation

  • Nadezda Sukhorukova
    • Categories Generalized Convexity/Monoticity, Nonsmooth Optimization, Optimization of Systems modeled by PDEs Tags , , ,

    In this paper, we show that minimax rational approximations can be enhanced by introducing a controlling parameter on the denominator of the rational function. This is implemented by adding a small set of linear constraints to the underlying optimization problem. The modification integrates naturally into approximation models formulated as linear programming problems. We demonstrate our … Read more

    Novel closed-loop controllers for fractional linear quadratic tracking systems

  • Malmir Iman
    • Categories Applications - Science and Engineering, Approximation Algorithms, Systems governed by Differential Equations Optimization Tags , , , , ,

    A new method for finding closed-loop optimal controllers of fractional tracking quadratic optimal control problems is introduced. The optimality conditions for the fractional optimal control problem are obtained. Illustrative examples are presented to show the applicability and capabilities of the method. ArticleDownload View PDF

    Clean Electricity Transition under Technology Cost and Efficiency Uncertainty for Distributed Energy Systems: A Multi-Stage Stochastic Programming Framework

  • Ahmet Emir Şener
  • Burak Kocuk
  • Tuğçe Yüksel
    • Categories Energy, Stochastic Programming Tags , , ,

    The decarbonization of energy systems is an essential component of global climate mitigation, yet such transitions involve substantial capital requirements, ongoing technological progress, and the operational complexities of renewable integration. This study presents a dynamic strategic planning framework that applies multi-stage stochastic programming to guide clean electricity transitions for distributed energy systems. The model jointly … Read more

    Two approaches to piecewise affine approximation

  • Nadezda Sukhorukova
    • Categories Applications - OR and Management Sciences, Approximation Algorithms, Data-Mining Tags , , ,

    The problem of approximation by piecewise affine functions has been studied for several decades (least squares and uniform approximation). If the location of switches from one affine piece to another (knots for univariate approximation) is known the problem is convex and there are several approaches to solve this problem. If the location of such switches … Read more

    Algorithmic Approaches for Identifying the Trade-off between Pessimism and Optimism in a Stochastic Fixed Charge Facility Location Problem

  • Man Yiu Tsang
  • Karmel S. Shehadeh
    • Categories Facility Planning and Design, Robust Optimization, Stochastic Programming Tags , , ,

    We introduce new algorithms to identify the trade-off (TRO) between adopting a distributional belief and hedging against ambiguity when modeling uncertainty in a capacitated fixed charge facility location problem (CFLP). We first formulate a TRO model for the CFLP (TRO-CFLP), which determines the number of facilities to open by minimizing the fixed establishment cost and … Read more

    ASMOP: Additional sampling stochastic trust region method for multi-objective problems

  • Nataša Krklec Jerinkić
  • Luka Rutešić
    • Categories Multi-Criteria Optimization, Optimization of Systems modeled by PDEs, Stochastic Programming Tags , , , , ,

    We consider an unconstrained multi-criteria optimization problem with finite sum objective functions. The proposed algorithm belongs to a non-monotone trust-region framework where additional sampling approach is used to govern the sample size and the acceptance of a candidate point. Depending on the problem, the method can result in a mini-batch or an increasing sample size … Read more

    A relax-fix-and-exclude algorithm for an MINLP problem with multilinear interpolations

  • Bruno Machado Pacheco
  • Laio Seman
    • Categories (Mixed) Integer Nonlinear Programming, Chemical Engineering, Global Optimization Applications Tags , ,

    This paper introduces a novel algorithm for Mixed-Integer Nonlinear Programming (MINLP) problems with multilinear interpolations of look-up tables. These problems arise when objectives or constraints contain black-box functions only known at a finite set of evaluations on a predefined grid. We derive a piecewise-linear relaxation for the multilinear interpolants, which require an MINLP formulation. Supported … Read more

    Interpretable SHAP-bounded Bayesian Optimization for Underwater Acoustic Metamaterial Coating Design

  • Elnaz Hajizadeh
    • Categories Civil and Environmental Engineering, Mechanical Engineering Tags , , , ,

    We developed an interpretability informed Bayesian optimization framework to optimize underwater acoustic coatings based on polyurethane elastomers with embedded metamaterial features. A data driven model was employed to analyze the relationship between acoustic performance, specifically sound absorption and the corresponding design variables. By leveraging SHapley Additive exPlanations (SHAP), a machine learning interpretability tool, we identified … Read more