RISCOS NÚÑEZ , Agustín

The purpose of the present work is to give a general idea about the existing results and open problems concerning the study of complexity classes within the membrane computing framework. To this aim, membrane systems (seen as computing devices) are briefly introduced, providing the basic definition and summarizing the key ideas, trying to cover...

A P system based general framework for modeling ecosystems dynamics will be described. Roughly speaking, the idea is to use several regions (environments) that can be connected, each of them containing a probabilistic P system with active membranes (having identical skeleton for every environment). Some real case studies will be displayed,...

Esta memoria está estructurada en capítulos cuyos contenidos pasamos a describir sucintamente. En el Capítulo 1 se hace una breve introducción histórica de la Teoría de la Computabilidad, analizándose las limitaciones y potencia de los modelos que formalizan el concepto de procedimiento mecánico, así como de la Teoría de la Complejidad...

Some of the theoretical open problems and current challenges concerning P systems from a theoretical perspective will be discussed, focusing on results related to searching bounds for computational com- plexity classes in general, and to the P vs NP problem and the P ̆aun's conjecture in particular. Membrane computing is already a mature field,...

DP is the class of problems that are the differences between two languages from NP. Most difficult problems from DP are called DP-complete problems, that can be seen as the conjunction of an NP-complete problem and a co-NP-complete problem. It is easy to see that the problem P vs NP is equivalent to the problem P vs DP, and therefore...

In 2005, Gh. Păun raised an interesting question concerning the role of electrical charges in P systems with active membranes from a complexity point of view. Specifically, he formulated a question about the computational efficiency of polarization-less P systems with dissolution rules and division rules only for elementary membranes....

Earlier solutions to decision problems by means of P systems used many counter objects to control the synchronization of different stages in a computation (usually as many counters as the stage must last in the worst case). In this paper we propose a way to replace those counters with some spacial objects for each stage. Furthermore,...

We improve, by using register machines, some existing universality results for specific models of P systems. P systems with membrane creation are known to generate all recursively enumerable sets of vectors of non-negative integers, even when no region (except the environment) contains more than one object of the same kind.We showhere that they...

We improve, by using register machines, some existing universality results for specific models of P systems. P systems with membrane creation are known to generate all recursively enumerable sets of vectors of non-negative integers, even when no region (except the environment) contains more than one object of the same kind. We here show that...

We present the first membrance computing solution to the Subset-Sum problem using a family of deterministic P systems with active membranes. We do not use priority among rules, membrane dissolution nor cooperation; it suffices to control the electrical charges of the membranes and to introduce some counters. The number of steps of any...

Up to now, P systems dealing with numerical problems have been rarely considered in the literature. In this paper we present an effective solution to the Knapsack problem using a family of deterministic P systems with active membranes using 2-division. We show that the number of steps of any computation is of linear order, but polynomial time...

The reconstruction of particle trajectories, tracking, is a central process in the reconstruction of particle collisions in High Energy Physics detectors. At the LHCb detector in the Large Hadron Collider, bunches of particles collide 30 million times per second. These collisions produce about 109 particle trajectories per second that need to...

This paper is a tribute to Prof. Mario de Jesús Pérez- Jiménez. An overview of modelling applications in membrane computing has been compiled, trying to narrate it from a historical perspective and including numerous bibliographical references. Since being exhaustive was obviously out of scope, this quick tour on almost two decades of...

In tissue P systems several cells (elementary membranes) communicate through symport/antiport rules, thus carrying out a computation. We add to such systems the basic feature of (cell–like) P systems with active membranes – the possibility to divide cells. As expected (as it is the case for P systems with active membranes), in this way we get...

In the last time, several e®orts were made in order to remove the polarization of membranes from P systems with active membranes; the present paper is a contribution in this respect. In order to compensate the loss of power represented by avoiding polarizations, we introduce tables of rules: each membrane has associated several sets of rules,...

In tissue P systems several cells (elementary membranes) commu- nicate through symport/antiport rules, thus carrying out a computation. We add to such systems the basic feature of (cell) P systems with active membranes { the possibility to divide cells. As expected (as it is the case for P systems with active membranes), in this way we get the...

The Rete algorithm is a well-known algorithm in rule-based production systems which builds directed acyclic graphs that represent higher-level rule sets. This allows the rule-based systems to avoid complete re-evaluation of all conditions of the rules each step in order to check the applicability of the rules and, therefore, the computational e...

One of the major challenges that current P systems simulators have to deal with is to be as efficient as possible. A P system is syntactically described as a membrane structure delimiting regions where multisets of objects evolve by means of evolution rules. According to that, on each computation step, the applicability of the rules for the...

Membrane computing is a biologically inspired computational paradigm. Motivated by brane calculi we investigate membrane systems which differ from conventional membrane systems by the following features: (1) biomolecules (proteins) can move through the regions of the systems, and can attach onto (and de-attach from) membranes, and (2) membranes...

We consider the idea of controlling the evolution of a membrane system. In particular, we investigate a model of membrane systems using promoted rules, where a string of promoters (called the control string) "travels" through the regions, activating the rules of the system. This control string is present in the skin region at the beginning of...