A multiplier adjustment method for the generalized assignment problem
Management Science
Finding embedded network rows in linear programs. I. Extraction heuristics
Management Science
A surrogate and Lagrangian approach to constrained network problems
Annals of Operations Research
New crash procedures for large systems of linear constraints
Mathematical Programming: Series A and B
Computers and Operations Research
Network flows: theory, algorithms, and applications
Network flows: theory, algorithms, and applications
Computers and Operations Research
Modern heuristic techniques for combinatorial problems
Dynamic factorization in large-scale optimization
Mathematical Programming: Series A and B
Advances in linear and integer programming
A hybrid algorithm for solving network flow problems with side constraints
Computers and Operations Research
Detecting Embedded Networks in LP Using GUB Structures and IndependentSet Algorithms
Computational Optimization and Applications
Strategies for Creating Advanced Bases for Large-Scale Linear Programming Problems
INFORMS Journal on Computing
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In this paper, we investigate how an embedded pure network structure arising in many linear programming (LP) problems can be exploited to create improved sparse simplex solution algorithms. The original coefficient matrix is partitioned into network and non-network parts. For this partitioning, a decomposition technique can be applied. The embedded network flow problem can be solved to optimality using a fast network flow algorithm. We investigate two alternative decompositions namely, Lagrangean and Benders. In the Lagrangean approach, the optimal solution of a network flow problem and in Benders the combined solution of the master and the subproblem are used to compute good (near optimal and near feasible) solutions for a given LP problem. In both cases, we terminate the decomposition algorithms after a preset number of passes and active variables identified by this procedure are then used to create an advanced basis for the original LP problem. We present comparisons with unit basis and a well established crash procedure. We find that the computational results of applying these techniques to a selection of Netlib models are promising enough to encourage further research in this area.