@article {647, title = {P Systems: Computing the Period of Irreducible Markov Chains}, journal = {International Journal of Computers, Communications and Control}, volume = {4}, year = {2009}, month = {30/2009}, pages = {291-300}, publisher = {Agora University Editing House - CCC Publications}, address = {Oradea, Romania}, abstract = {It is well known that any irreducible and aperiodic Markov chain has exactly one stationary distribution, and for any arbitrary initial distribution, the sequence of distributions at time n converges to the stationary distribution, that is, the Markov chain is approaching equilibrium as n tends to infinity. In this paper, a characterization of the aperiodicity in existential terms of some state is given. At the same time, a Psystem with external output is associated with any irreducible Markov chain. The designed system provides the aperiodicity of that Markov chain and spends a polynomial amount of resources with respect to the size of the input. A comparative analysis with respect to another known solution is described.}, keywords = {Markov chain, Membrane computing, P systems}, issn = {1841-9836}, url = {http://www.journal.univagora.ro/?page=article_details\&id=374}, author = {M{\'o}nica Cardona and M. Angels Colomer and Agust{\'\i}n Riscos-N{\'u}{\~n}ez and Miquel Rius-Font} }