Affiliations: Department of Computer Science and Artificial
Intelligence, University of Sevilla, Av. Reina Mercedes, 41012, Sevilla, Spain.
martew@inwind.it | Department of Computer Science and Artificial
Intelligence, University of Sevilla, Av. Reina Mercedes, 41012, Sevilla, Spain,
and Department of Informatics and Numerical Methods, Ovidius University of
Constantza, 124 Mamaia Bv., Constantza, Romania. dsburlan@univ-ovidius.ro
Note: [] Address for correspondence: Department of Computer Science and
Artificial Intelligence, University of Sevilla, Av. Reina Mercedes, 41012,
Sevilla, Spain
Abstract: Membrane systems are parallel computational devices inspired from
the cell functioning. Since the original definition, a standard feature of
membrane systems is the fact that each rule of the system is executed in
exactly one time-unit. However, this hypothesis seems not to have a counterpart
in real world. In fact, in cells, chemical reactions might take different times
to be exe-cuted. Therefore, a natural step is to associate to each rule of a
membrane system a certain time of execution. We are interested in membrane
systems, called time-free, working independently from the assigned execution
time of the rules. A basic and interesting problem in time-free membrane
systems consists in the synchronization of different rules, running in
parallel, and having unknown execution times. Here, we present different ways
to approach this problem within the framework of membrane systems. Several
research proposals are also suggested.
Keywords: Membrane systems, synchronization, time, time-free, universality
