Vendredi 12 décembre 2003.<br/>
Orateur : Stanislav Volkov (University of Bristol).<br/>
Titre :
A polling system with 3 queues and 1 server
is almost surely periodic when transient.

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Résumé :<br/>
We consider a queuing system with three queues (nodes) and one server.
The arrival and service rates at each node are such that the system
overall is overloaded,
while no individual node is.
The service discipline is the following: once the server is at node j,
it stays there until it serves all customers in the queue.
After this, the server moves to the "more expensive" of the two queues.
We will show that a.s. there will be a periodicity in the order of
services, as
suggested by the behavior of the corresponding dynamical systems.