integer programming

A Reformulation Technique to Solve Polynomial Optimization Problems with Separable Objective Functions of Bounded Integer Variables

  • Andrew C. Trapp
  • Pitchaya Wiratchotisatian
    • Categories (Mixed) Integer Nonlinear Programming, Global Optimization Theory, Nonlinear Optimization Tags , , ,

    Real-world problems are often nonconvex and involve integer variables, representing vexing challenges to be tackled using state-of-the-art solvers. We introduce a mathematical identity-based reformulation of a class of polynomial integer nonlinear optimization (PINLO) problems using a technique that linearizes polynomial functions of separable and bounded integer variables of any degree. We also introduce an alternative … Read more

    On the exactness of the eps-constraint method for bi-objective integer nonlinear programming

  • Marianna De Santis
  • Daniele Patria
    • Categories (Mixed) Integer Nonlinear Programming, Multi-Criteria Optimization Tags , , ,

    The eps-constraint method is a well-known scalarization technique used for multiobjective optimization. We explore how to properly define the step size parameter of the method in order to guarantee its exactness when dealing with problems having two nonlinear objective functions and integrality constraints on the variables. Under specific assumptions, we prove that the number of … Read more

    High quality timetables for Italian schools

  • Claudio Crobu
  • Massimo Di Francesco
  • Enrico Gorgone
    • Categories (Mixed) Integer Linear Programming, Scheduling Tags , ,

    This work introduces a complex variant of the timetabling problem, which is motivated by the case of Italian schools. The new requirements enforce to (i) provide the same idle times for teachers, (ii) avoid consecutive \emph{heavy} days, (iii) limit daily multiple lessons for the same class, (iv) introduce shorter time units to differentiate entry and … Read more

    Total Coloring and Total Matching: Polyhedra and Facets

  • Luca Ferrarini
  • Stefano Gualandi
    • Categories (Mixed) Integer Linear Programming, 0-1 Programming, Cutting Plane Approaches Tags , , ,

    A total coloring of a graph G = (V, E) is an assignment of colors to vertices and edges such that neither two adjacent vertices nor two incident edges get the same color, and, for each edge, the end-points and the edge itself receive different colors. Any valid total coloring induces a partition of the … Read more

    The Stochastic Pseudo-Star Degree Centrality Problem

  • Mustafa Can Camur
  • Thomas C. Sharkey
  • Chrysafis Vogiatzis
    • Categories Combinatorial Optimization, Integer Programming Tags , , ,

    We introduce the stochastic pseudo-star degree centrality problem, which focuses on a novel probabilistic group-based centrality metric. The goal is to identify a feasible induced pseudo-star, which is defined as a collection of nodes forming a star network with a certain probability, such that it maximizes the sum of the individual probabilities of unique assignments … Read more

    Algorithms for the Clique Problem with Multiple-Choice Constraints under a Series-Parallel Dependency Graph

  • Andreas Bärmann
  • Patrick Gemander
  • Maximilian Merkert
  • Ann-Kathrin Wiertz
  • Francisco Javier Zaragoza Martínez
    • Categories Dynamic Programming, Graphs and Matroids, Polyhedra Tags , , , ,

    The clique problem with multiple-choice constraints (CPMC), i.e. the problem of finding a k-clique in a k-partite graph with known partition, occurs as a substructure in many real-world applications, in particular scheduling and railway timetabling. Although CPMC is NP-complete in general, it is known to be solvable in polynomial time when the so-called dependency graph … Read more

    Total Coloring and Total Matching: Polyhedra and Facets

  • Luca Ferrarini
  • Stefano Gualandi
    • Categories (Mixed) Integer Linear Programming, Cutting Plane Approaches, Polyhedra Tags , , ,

    A total coloring of a graph G = (V, E) is an assignment of colors to vertices and edges such that neither two adjacent vertices nor two incident edges get the same color, and, for each edge, the end-points and the edge itself receive a different color. Any valid total coloring induces a partition of … Read more

    Political districting to minimize cut edges

  • Austin Buchanan
  • Hamidreza Validi
    • Categories Combinatorial Optimization, Integer Programming, Network Optimization Tags , , , , , , , ,

    When constructing political districting plans, prominent criteria include population balance, contiguity, and compactness. The compactness of a districting plan, which is often judged by the “eyeball test,” has been quantified in many ways, e.g., Length-Width, Polsby-Popper, and Moment-of-Inertia. This paper considers the number of cut edges, which has recently gained traction in the redistricting literature … Read more

    Solving Bang-Bang Problems Using The Immersed Interface Method and Integer Programming

  • Sarah Strikwerda
  • Ryan Vogt
    • Categories Combinatorial Optimization, Nonlinear Optimization Tags , , ,

    In this paper we study numerically solving optimal control problems with bang-bang control functions. We present a formal Lagrangian approach for solving the optimal control problem, and address difficulties encountered when numerically solving the state and adjoint equations by using the immersed interface method. We note that our numerical approach does not approximate the discontinuous … Read more

    Lower Bounds on the Size of General Branch-and-Bound Trees

  • Santanu S. Dey
  • Yatharth Dubey
  • Marco Molinaro
    • Categories 0-1 Programming, Branch and Cut Algorithms, Global Optimization Theory Tags , ,

    A \emph{general branch-and-bound tree} is a branch-and-bound tree which is allowed to use general disjunctions of the form $\pi^{\top} x \leq \pi_0 \,\vee\, \pi^{\top}x \geq \pi_0 + 1$, where $\pi$ is an integer vector and $\pi_0$ is an integer scalar, to create child nodes. We construct a packing instance, a set covering instance, and a … Read more