Marian Gheorghe, Gheorghe Paun and Mario de Jesus Perez-Jimenez
The present volume contains a selection of papers related to two international meetings devoted to Membrane Computing, the first edition of the Asian Conference on Membrane Computing, ACMC, organized in Wuhan, P.R. of China, between October 15 and October 18, 2012, by Huazhong University of Science and Technology, and the Eleventh Brainstorming Week on Membrane Computing (BWMC), held in Sevilla, from February 4 to February 8, 2013, in the organization of the Research Group on Natural Computing (http://www.gcn.us.es) from the Department of Computer Science and Artificial Intelligence of Sevilla University.
In both cases, pre-proceedings volumes were published; here, only a few of the papers were selected (the first criterion being their quality, but also in such a way to provide a balanced image of this research area, at about fifteen years since its beginning). The papers have passed the usual refereeing process and are included in the present volume in a revised version.
Membrane computing is a branch of natural computing whose aim is to abstract computing models (data structures, operations about them, ways to control the computation, computing architectures) from the organization and the functioning of the living cell and from populations of cells. The area was initiated in the fall of 1998, and it is already well developed, both at the theoretical level (computing power and computing efficiency) and in what concerns the applications (from biology to computer graphics and robot control). The proposed models are called P systems. Up-dated information about membrane computing can be found at the domain website, at http://psystems.ppage.eu, with a comprehensive presentation (at the level of year 2009) provided by The Oxford Handbook of Membrane Computing (Gh. Paun, G. Rozenberg, A. Salomaa, eds.), published at Oxford University Press in 2010.
As the key events related to membrane computing – conferences, workshops and brainstorming activities – have been organized in Europe, the ACMC was intended to bring together researchers that do not attend on a regular basis the European meetings, especially from Asia. The conference was organized by Huazhong University of Science and Technology from Wuhan, being sponsored by the National Natural Science Foundation of R.P. of China. Three papers were selected, dealing with modeling logic gene networks with probabilistic dynamic P systems (L. Valencia-Cabrera, M. Garcıa-Quismondo, M.J. Perez-Jimenez, Y. Su, H. Yu, and L. Pan), providing polynomial-time solutions to constraint satisfaction problems by using neural-like P systems (L. Xu, X. Zeng, and P. Jeavons), and automatic design of cell-like P systems by using evolutionary methods (Z. Ou, G. Zhang, T. Wang, and X. Huang).
The first edition of BWMC was organized at the beginning of February 2003 in Rovira i Virgili University, Tarragona, and all the next editions took place in Sevilla at the beginning of February, each year. The meeting is conceived as a period of active interaction among the participants, with the emphasis on exchanging ideas and cooperation. Several “provocative” talks were delivered, mainly devoted to open problems, research topics, conjectures waiting for proofs, followed by an intense cooperation among the participants. The efficiency of this type of meetings was again proved to be very high and the volume published by Fenix Editora, Sevilla, in June 2013, containing the 18 papers issued during the meeting, illustrates this assertion.
Out of these papers, four were selected for the present volume. They deal with a variety of topics, from mathematical foundations (G. Ciobanu and D. Sburlan introduce a new class of P systems, with biological inspiration, while A. Leporati, A.E. Porreca, C. Zandron, and G. Mauri give rather strong improvements of universality results for enzymatic numerical P systems, a class of P systems with applications in robot control), to computer simulation/ implementation (C. Graciani, M.A. Gutierey-Naranjo, I. Perez-Hurtado, A. Riscos-Nunez, and A. Romero-Jimenez discuss the usefulness of the Rete algorithm in simulating P systems, while M.A. Martınez-del-Amor, J. Perez- Carrasco, M.J. P´erez-Jimenez describe part of the Sevilla group experience in simulating P systems on GPU).
The Eleventh Brainstorming Week on Membrane Computing was supported from various sources: (i) Proyecto de Excelencia de la Junta de Andalucıa, grant TIC 581, (ii) Proyecto de Excelencia con investigador de reconocida val´ıa, de la Junta de Andaluc´ıa, grant P08 – TIC 04200, (iii) Proyecto del Ministerio de Educaci´on y Ciencia, grant TIN2006 – 13425, (iv) Instituto de Matem´aticas de la Universidad de Sevilla (IMUS), (v) Consejerıa de Innovacion, Ciencia y Empresa de la Junta de Andalucıa, as well as by the Department of Computer Science and Artificial Intelligence from Sevilla University.