Month: August 2025

On Subproblem Tradeoffs in Decomposition and Coordination of Multiobjective Optimization Problems

  • Philip de Castro
  • Margaret Wiecek
    • Categories Multi-Criteria Optimization

    Multiobjective optimization is widely used in applications for modeling and solving complex decision-making problems. To help resolve computational and cognitive difficulties associated with problems which have more than three or four objectives, we propose a decomposition and coordination methodology to support decision making for large multiobjective optimization problems (MOPs) with global, quasi-global, and local variables. … Read more

    Integrated Bus Fleet Electrification Planning Through Accelerated Logic-Based Benders Decomposition and Restriction Heuristics

  • Robin Legault
  • Filipe Cabral
  • Xu Andy Sun
    • Categories (Mixed) Integer Linear Programming, Facility Planning and Design, Transportation Tags , ,

    To meet sustainability goals and regulatory requirements, transit agencies worldwide are planning partial and complete transitions to electric bus fleets. This paper presents the first comprehensive and computationally efficient multi-period optimization framework integrating the key planning decisions necessary to support such electrification initiatives. Our model, formulated as a two-stage integer program with integer subproblems, jointly … Read more

    A second-order cone representable class of nonconvex quadratic programs

  • Aida Khajavirad
    • Categories (Mixed) Integer Nonlinear Programming, Global Optimization Theory, Integer Programming Tags , , , ,

    We consider the problem of minimizing a sparse nonconvex quadratic function over the unit hypercube. By developing an extension of the Reformulation Linearization Technique (RLT) to continuous quadratic sets, we propose a novel second-order cone (SOC) representable relaxation for this problem. By exploiting the sparsity of the quadratic function, we establish a sufficient condition under … Read more

    A Data-Driven County-Level Budget Allocation Model for Opioid Crisis Management: Insights from West Virginia

  • Ankit Bansal
  • Jean-Philippe P. Richard
    • Categories Applications - OR and Management Sciences, Integer Programming, Optimization in Data Science Tags

    Problem definition. The opioid crisis has remained a major public health challenge in the United States for many years. This study develops a data-driven decision support framework to guide policymakers in allocating county-level budgets across multiple expenditure categories in order to address the opioid crisis. Methodology/results. We compile and curate a detailed dataset on fiscal … Read more

    A user manual for cuHALLaR: A GPU accelerated low-rank semidefinite programming Solver

  • Jacob Aguirre
  • Diego Cifuentes
  • Vincent Guigues
  • Renato D.C. Monteiro
  • Victor Hugo Nascimento
  • Arnesh Sujanani
    • Categories Nonlinear Optimization, Optimization Software and Modeling Systems, Semi-definite Programming Tags , , , , , ,

    We present a Julia-based interface to the precompiled HALLaR and cuHALLaR binaries for large-scale semidefinite programs (SDPs). Both solvers are established as fast and numerically stable, and accept problem data in formats compatible with SDPA and a new enhanced data format taking advantage of Hybrid Sparse Low-Rank (HSLR) structure. The interface allows users to load … Read more

    Polyconvex double well functions

  • Didier Henrion
  • Martin Kružík
    • Categories Generalized Convexity/Monoticity, Systems governed by Differential Equations Optimization Tags ,

    We investigate polyconvexity of the double well function $f(X) := |X-X_1|^2|X-X_2|^2$ for given matrices $X_1, X_2 \in \R^{n \times n}$. Such functions are fundamental in the modeling of phase transitions in materials, but their non-convex nature presents challenges for the analysis of variational problems. We prove that $f$ is polyconvex if and only if the … Read more

    On the boundedness of multipliers in augmented Lagrangian methods for mathematical programs with complementarity constraints

  • Roberto Andreani
  • Mariana da Rosa
  • Leonardo D. Secchin
    • Categories Nonlinear Optimization Tags , , ,

    In this paper, we present a theoretical analysis of augmented Lagrangian (AL) methods applied to mathematical programs with complementarity constraints (MPCCs). Our focus is on a variant that reformulates the complementarity constraints using slack variables, where these constraints are handled directly in the subproblems rather than being penalized. We introduce specialized constraint qualifications (CQs) of … Read more

    A First Order Algorithm on an Optimization Problem with Improved Convergence when Problem is Convex

  • Chee-Khian Sim
    • Categories Convex and Nonsmooth Optimization, Nonlinear Optimization Tags , , , ,

    We propose a first order algorithm, a modified version of FISTA, to solve an optimization problem with an objective function that is the sum of a possibly nonconvex function, with Lipschitz continuous gradient, and a convex function which can be nonsmooth. The algorithm is shown to have an iteration complexity of \(\mathcal{O}(\epsilon^{-2})\) to find an … Read more

    Data-Driven Contextual Optimization with Gaussian Mixtures: Flow-Based Generalization, Robust Models, and Multistage Extensions

  • YoungChul Yoon
  • Grani A. Hanasusanto
  • Yijie Wang
    • Categories Robust Optimization, Stochastic Programming Tags , , , , ,

    Contextual optimization enhances decision quality by leveraging side information to improve predictions of uncertain parameters. However, existing approaches face significant challenges when dealing with multimodal or mixtures of distributions. The inherent complexity of such structures often precludes an explicit functional relationship between the contextual information and the uncertain parameters, limiting the direct applicability of parametric … Read more