@misc{FroylandKochMegowetal., author = {Froyland, Gary and Koch, Thorsten and Megow, Nicole and Duane, Emily and Wren, Howard}, title = {Optimizing the Landside Operation of a Container Terminal}, url = {http://nbn-resolving.de/urn:nbn:de:0297-zib-9004}, number = {06-06}, abstract = {This paper concerns the problem of operating a landside container exchange area that is serviced by multiple semi-automated rail mounted gantry cranes (RMGs) that are moving on a single bi-directional traveling lane. Such a facility is being built by Patrick Corporation at the Port Botany terminal in Sydney. The gantry cranes are a scarce resource and handle the bulk of container movements. Thus, they require a sophisticated analysis to achieve near optimal utilization. We present a three stage algorithm to manage the container exchange facility, including the scheduling of cranes, the control of associated short-term container stacking, and the allocation of delivery locations for trucks and other container transporters. The key components of our approach are a time scale decomposition, whereby an integer program controls decisions across a long time horizon to produce a balanced plan that is fed to a series of short time scale online subproblems, and a highly efficient space-time divisioning of short term storage areas. A computational evaluation shows that our heuristic can find effective solutions for the planning problem; on real-world data it yields a solution at most~8\\% above a lower bound on optimal RMG utilization.}, language = {en} } @article{BolandDumitrescuFroylandetal.2009, author = {Boland, Natashia and Dumitrescu, Irina and Froyland, Gary and Gleixner, Ambros}, title = {LP-based disaggregation approaches to solving the open pit mining production scheduling problem with block processing selectivity}, series = {Computers \& Operations Research}, volume = {36}, journal = {Computers \& Operations Research}, pages = {1064 -- 1089}, year = {2009}, language = {en} } @article{FroylandKochMegowetal.2008, author = {Froyland, Gary and Koch, Thorsten and Megow, Nicole and Duane, Emily and Wren, Howard}, title = {Optimizing the Landside Operation of a Container Terminal}, series = {OR Spectrum}, volume = {30}, journal = {OR Spectrum}, number = {1}, doi = {10.1007/s00291-007-0082-7}, pages = {53 -- 75}, year = {2008}, language = {en} } @article{FroylandMaherWu, author = {Froyland, Gary and Maher, Stephen J. and Wu, Cheng-Lung}, title = {The recoverable robust tail assignment problem}, series = {Transportation Science}, volume = {48}, journal = {Transportation Science}, number = {3}, doi = {10.1287/trsc.2013.0463}, pages = {351 -- 372}, abstract = {Schedule disruptions are commonplace in the airline industry with many flight-delaying events occurring each day. Recently there has been a focus on introducing robustness into airline planning stages to reduce the effect of these disruptions. We propose a recoverable robustness technique as an alternative to robust optimisation to reduce the effect of disruptions and the cost of recovery. We formulate the recoverable robust tail assignment problem (RRTAP) as a stochastic program, solved using column generation in the master and subproblems of the Benders' decomposition. We implement a two-phase algorithm for the Benders' decomposition and identify pareto-optimal cuts. The RRTAP includes costs due to flight delays, cancellation, and passenger rerouting, and the recovery stage includes cancellation, delay, and swapping options. To highlight the benefits of simultaneously solving planning and recovery problems in the RRTAP we compare our tail assignment solution against current approaches from the literature. Using airline data we demonstrate that by developing a better tail assignment plan via the RRTAP framework, one can reduce recovery costs in the event of a disruption.}, language = {en} }