67 citations · 72 across the 23 of their papers we have counts for
8 papers · 1 filter
Network Coding: An Optimization Approach
Christopher Hojny, Altan B. Kilic, Alberto Ravagnani
We consider the problem of computing the capacity of a coded, multicast network over a small alphabet. We introduce a novel approach to this problem based on mixed integer programm…
Handling Sub-symmetry in Integer Programming using Activation Handlers
Christopher Hojny, Tom Verhoeff, Sten Wessel
Symmetry in integer programs (IPs) can be exploited in order to reduce solving times. Usually only symmetries of the original IP are handled, but new symmetries may arise at some n…
A Unified Framework for Symmetry Handling
Jasper van Doornmalen, Christopher Hojny
Handling symmetries in optimization problems is essential for devising efficient solution methods. In this article, we present a general framework that captures many of the already…
Integer Programming Models for Round Robin Tournaments
Jasper van Doornmalen, Christopher Hojny, Roel Lambers +1
Round robin tournaments are omnipresent in sport competitions and beyond. We propose two new integer programming formulations for scheduling a round robin tournament, one of which…
A flow-based formulation for parallel machine scheduling using decision diagrams
Daniel Kowalczyk, Roel Leus, Christopher Hojny +1
We present a new flow-based formulation for identical parallel machine scheduling with a regular objective function and without idle time. The formulation is constructed with the h…
The role of rationality in integer-programming relaxations
Manuel Aprile, Gennadiy Averkov, Marco Di Summa +1
For a finite set that can be represented as for some polyhedron , we call a relaxation of and define the relaxation co…
Efficient MIP Techniques for Computing the Relaxation Complexity
Gennadiy Averkov, Christopher Hojny, Matthias Schymura
The relaxation complexity rc(X) of the set of integer points X contained in a polyhedron is the minimal number of inequalities needed to formulate a linear optimization problem ove…
Efficient Propagation Techniques for Handling Cyclic Symmetries in Binary Programs
Jasper van Doornmalen, Christopher Hojny
The presence of symmetries of binary programs typically degrade the performance of branch-and-bound solvers. In this article, we derive efficient variable fixing algorithms to disc…