On the solution of highly degenerate linear programs
Mathematical Programming: Series A and B
An Unsymmetric-Pattern Multifrontal Method for Sparse LU Factorization
SIAM Journal on Matrix Analysis and Applications
Simultaneous Vehicle and Crew Scheduling in Urban Mass Transit Systems
Transportation Science
Dynamic Aggregation of Set-Partitioning Constraints in Column Generation
Operations Research
Multi-phase dynamic constraint aggregation for set partitioning type problems
Mathematical Programming: Series A and B
An Improved Primal Simplex Algorithm for Degenerate Linear Programs
INFORMS Journal on Computing
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The Improved Primal Simplex (IPS) algorithm [Elhallaoui I, Metrane A, Desaulniers G, Soumis F. An Improved Primal Simplex algorithm for degenerate linear programs. SIAM Journal of Optimization, submitted for publication] is a dynamic constraint reduction method particularly effective on degenerate linear programs. It is able to achieve a reduction in CPU time of over a factor of three on some problems compared to the commercial implementation of the simplex method CPLEX. We present a number of further improvements and effective parameter choices for IPS. On certain types of degenerate problems, our improvements yield CPU times lower than those of CPLEX by a factor of 12.