32,823 research outputs found
A Simulation Framework for Fast Design Space Exploration of Unmanned Air System Traffic Management Policies
The number of daily small Unmanned Aircraft Systems (sUAS) operations in
uncontrolled low altitude airspace is expected to reach into the millions. UAS
Traffic Management (UTM) is an emerging concept aiming at the safe and
efficient management of such very dense traffic, but few studies are addressing
the policies to accommodate such demand and the required ground infrastructure
in suburban or urban environments. Searching for the optimal air traffic
management policy is a combinatorial optimization problem with intractable
complexity when the number of sUAS and the constraints increases. As the
demands on the airspace increase and traffic patterns get complicated, it is
difficult to forecast the potential low altitude airspace hotspots and the
corresponding ground resource requirements. This work presents a Multi-agent
Air Traffic and Resource Usage Simulation (MATRUS) framework that aims for fast
evaluation of different air traffic management policies and the relationship
between policy, environment and resulting traffic patterns. It can also be used
as a tool to decide the resource distribution and launch site location in the
planning of a next-generation smart city. As a case study, detailed comparisons
are provided for the sUAS flight time, conflict ratio, cellular communication
resource usage, for a managed (centrally coordinated) and unmanaged (free
flight) traffic scenario.Comment: The Integrated Communications Navigation and Surveillance (ICNS)
Conference in 201
Disruption management in passenger railway transportation.
This paper deals with disruption management in passengerrailway transportation. In the disruption management process, manyactors belonging to different organizations play a role. In this paperwe therefore describe the process itself and the roles of thedifferent actors.Furthermore, we discuss the three main subproblems in railwaydisruption management: timetable adjustment, and rolling stock andcrew re-scheduling. Next to a general description of these problems,we give an overview of the existing literature and we present somedetails of the specific situations at DSB S-tog and NS. These arethe railway operators in the suburban area of Copenhagen, Denmark,and on the main railway lines in the Netherlands, respectively.Since not much research has been carried out yet on OperationsResearch models for disruption management in the railway context,models and techniques that have been developed for related problemsin the airline world are discussed as well.Finally, we address the integration of the re-scheduling processesof the timetable, and the resources rolling stock and crew.
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