PhD position, Zaragoza, Spain

PhD position

at

Systems Engineering and Discrete Event Systems Group
(http://webdiis.unizar.es/GISED/gised/)
Department of Computer Science and Systems Engineering
University of Zaragoza,
Spain

The activities of the group are related to the modelling, analysis and
formal synthesis of some classes of artificial systems that are
interesting from a technical point of view (production systems, computer
systems, logistic systems, coordination systems, etc.). Usually more
adequately modelled by means of discrete event systems formalisms
(automata, Petri nets, process algebra,
queuing networks,...), the state explosion problem puts a
limit to most of the analysis or synthesis techniques. Relaxations
based on continuization appear as a possible way to overcome these
difficulties when largely populated systems, or systems with high
cadence are considered.

The position will be mainly focused on the formalism of continuous Petri
nets, defined relaxing the integrality constraint in a similar way as in
fluid queuing networks, and more specifically in optimization problems.

On the one hand, static optimization problems like resources
optimization (initial marking optimization), equipment selection (rate
and firing optimization) or processes and production subsystems
(structural optimization).

On the other hand, dynamic control of continuous Petri nets.
The desired continuous system controlling is based on the limitation of
the firing rate of transitions, in other words, limiting the speed of
system actions realization. In this way, the possible actions are
restricted: only system slowdown is possible and the actions have a
local marking dependent (state) upper limit. This fact makes difficult
to use many classical control techniques.
Also robustness and sensibility aspects on the controlled system will be
addressed.

Once the relaxed model has been analysed or a control synthesized, it is
necessary to interpret and to adapt the results for the original model.
It may be necessary, for instance, to apply a post-optimization to the
discrete reconstruction (reduce the relaxation) from the obtained
results. If we are considering a control policy design, we will need to
study how to build from that policy a new one for the discrete system
but fulfilling the specified requirements.

The main task for the accepted candidate will be to conduct
research towards his/her PhD. The candidate is expected to
complete the degree within 4 years.

Applicants must have MSc (or equivalent) degree in Computer Science,
Mathematics, Electrical/Electronics or Communications Engineering.
Knowledge on operational research, automatic control and computer
science will be specially welcome.

Application must be done at the web page of the Ministry of Education
(http://www.mec.es/ciencia/jsp/plantilla.jsp?area=becasfpi&id=11).
The application form for this year is not ready still, but should be
working in a few days.

For further information contact:

Laura Recalde (lrecalde@xxxxxxxxx)
Departamento de Informática e Ingeniería de Sistemas
Universidad de Zaragoza
Maria de Luna 1,
50018 Zaragoza, Spain