Airport gate assignment is a critical issue for the operation management of an airport. Airport gate assignment is to assign flights to gates according to their real-time arrival time and departure time, such that each flight is assigned to exactly one gate, and there is no conflict between two consecutive flights assigned to the same gate. We formulate the airport gate assignment as a stochast...

The airport runway is a scarce resource that must be shared by different runway operations (arrivals, departures and runway crossings). Given the possible sequences of runway events, careful Runway Operations Planning (ROP) is required if runway utilization is to be maximized. Thus, Runway Operations Planning (ROP) is a critical component of airport operations planning in general and surface op...

We first consider a single–server queue that serves a tagged MMPP–2 stream and a background MMPP–2 stream in a FIFO manner. The service time is exponentially distributed. For this queueing system, we obtain the CDF of the tagged inter-departure time, from which we can calculate the jitter, defined as a percentile of the inter–departure time. The formulation is exact, but the solution is obtaine...

—While communal roosting is fairly common in animals, the costs, benefits, and proximal factors influencing this behavior are poorly understood. Moreover, many species with communal roosting that have been studied to date have a strong association with humans; however, there have been few formal tests of how human activity might influence roosting behaviors. We studied roosting activity in the ...

We propose a new speed and departure time optimization algorithm for the Pollution-Routing Problem (PRP) which runs in quadratic time. This algorithm is embedded into an iterated local search-based metaheuristic to achieve a combined speed, scheduling and routing optimization. Extensive computational experiments are conducted on classic PRP benchmark instances. Allowing delayed departure times ...

Changes in the train schedule affect the train driver duties. If a train is cancelled or delayed, the driver assigned to the train task might not be able to reach the station of his next train departure in time. In practice, if a driver is not available for the train departure, another driver, for instance, a reserve, is assigned to the task. If there are no drivers available to cover the task ...

Train timetabling is a process of assigning suitable arrival and departure times to trains at the stations they visit and at key track junctions. It is desirable that the timetable focusses on passenger preferences and is operationally viable and profitable for the Train Operating Companies (TOCs). Many hard and soft constraints need to be considered relating to the track capacities, set of tra...

An attractor, in complex systems theory, is any state that is more easily or more often entered or acquired than departed or lost; attractor states therefore accumulate more members than non-attractors, other things being equal. In the context of language evolution, linguistic attractors include sounds, forms, and grammatical structures that are prone to be selected when sociolinguistics and la...