Performance aspects of a Lagrangian relaxation based heuris-tic for solving large 0-1 integer linear programs are discussed. In particular , we look at its application to airline and railway crew scheduling problems. We present a scalable parallelization of the original algorithm used in production at Carmen Systems AB, GG oteborg, Sweden, based on distributing the variables and a new sequentia...

Performance aspects of a Lagrangian relaxation based heuris-tic for solving large 0-1 integer linear programs are discussed. In particular , we look at its application to airline and railway crew scheduling problems. We present a scalable parallelization of the original algorithm used in production at Carmen Systems AB, GG oteborg, Sweden, based on distributing the variables and a new sequentia...

The need to operate commercial airlines world wide for 24 hours each day inevitably leads to problems of aircrew management: to the stresses of flying an aircraft must be added those of unsocial and irregular hours, time zone (transmeridian), climatic and cultural changes, sleep disturbances, and alterations to circadian rhythms. Fatigue is the main danger, since a decline in performance is lik...

The black and white traveling salesman problem (BWTSP) is de4ned on a graph G whose vertex set is partitioned into black and white vertices. The aim is to design a shortest Hamiltonian tour on G subject to two constraints: both the number of white vertices as well as the length of the tour between two consecutive black vertices are bounded above. The BWTSP has applications in airline scheduling...

The airline crew scheduling problem is the problem of assigning crew itineraries to flights. We develop a new approach for solving the problem that is based on enumerating hundreds of millions random pairings. The linear programming relaxation is solved first and then millions of columns with best reduced cost are selected for the integer program. The number of columns is further reduced by a l...

• Aircraft maintenance check scheduling optimization considering uncertainties. A tractable lookahead approximate dynamic programming (ADP) methodology is proposed. The ADP adopts a policy that uses deterministic and stochastic forecasts. makes decision its long-term impact. This paper proposes for aircraft scheduling, the uncertainty of daily utilization elapsed time. It framework, using hybri...

The airline industry has a long history of developing and applying optimization approaches to their myriad of scheduling problems, including designing flight schedules that maximize profitability while satisfying rules related to aircraft maintenance; generating cost-minimizing, feasible work schedules for pilots and flight attendants; and identifying implementable, lowcost changes to aircraft ...

abstract airlines brands are getting new identities in the electronic age. because of growing new technologies like internet, there will be new strategic opportunities for airline companies to position their brand. on the other hand, religious tourism's industry has a sustainable market in iran, because of cultural issues. a lot of passengers prefer to do their religious travels with an ai...