ON A PARTIAL AFFIRMATIVE ANSWER FOR A PĂUN'S CONJECTURE

2011 ◽  
Vol 22 (01) ◽  
pp. 55-64 ◽  
Author(s):  
IGNACIO PÉREZ-HURTADO ◽  
MARIO J. PÉREZ-JIMÉNEZ ◽  
AGUSTÍN RISCOS-NÚÑEZ ◽  
MIGUEL A. GUTIÉRREZ-NARANJO ◽  
MIQUEL RIUS-FONT
Keyword(s):  
Affirmative Answer ◽  
Positive Answer ◽  
Dependency Graph ◽  
P Systems ◽  
Complete Proof ◽  
Active Membranes ◽  
Hard Problems

At the beginning of 2005, Gheorghe Păun formulated a conjecture stating that in the framework of recognizer P systems with active membranes (evolution rules, communication rules, dissolution rules and division rules for elementary membranes), polarizations cannot be avoided in order to solve computationally hard problems efficiently (assuming that P ≠ NP ). At the middle of 2005, a partial positive answer was given, proving that the conjecture holds if dissolution rules are forbidden. In this paper we give a detailed and complete proof of this result modifying slightly the notion of dependency graph associated with recognizer P systems.

scholarly journals Elementary Active Membranes Have the Power of Counting

2014 ◽  
pp. 194-206
Author(s):  
Antonio E. Porreca ◽  
Alberto Leporati ◽  
Giancarlo Mauri ◽  
Claudio Zandron
Keyword(s):  
Polynomial Time ◽  
P Systems ◽  
Decision Problems ◽  
Active Membranes ◽  
Hard Problems ◽  
Whole Class ◽  
Uniformity Condition ◽  
Membrane Division

P systems with active membranes have the ability of solving computationally hard problems. In this paper, the authors prove that uniform families of P systems with active membranes operating in polynomial time can solve the whole class of PP decision problems, without using nonelementary membrane division or dissolution rules. This result also holds for families having a stricter uniformity condition than the usual one.

scholarly journals Elementary Active Membranes Have the Power of Counting

2011 ◽  
Vol 2 (3) ◽  
pp. 35-48 ◽  
Author(s):  
Antonio E. Porreca ◽  
Alberto Leporati ◽  
Giancarlo Mauri ◽  
Claudio Zandron
Keyword(s):  
Polynomial Time ◽  
P Systems ◽  
Decision Problems ◽  
Active Membranes ◽  
Hard Problems ◽  
Whole Class ◽  
Uniformity Condition ◽  
Membrane Division

P systems with active membranes have the ability of solving computationally hard problems. In this paper, the authors prove that uniform families of P systems with active membranes operating in polynomial time can solve the whole class of PP decision problems, without using nonelementary membrane division or dissolution rules. This result also holds for families having a stricter uniformity condition than the usual one.

scholarly journals Solution to PSPACE-Complete Problem Using P Systems with Active Membranes with Time-Freeness

2019 ◽  
Vol 2019 ◽  
pp. 1-8 ◽  
Author(s):  
Bosheng Song ◽  
Yuan Kong
Keyword(s):  
Execution Time ◽  
Cell Structure ◽  
P Systems ◽  
Biological Information ◽  
Natural Computing ◽  
Boolean Satisfiability Problem ◽  
Active Membranes ◽  
Hard Problems ◽  
And Behavior ◽  
Computing Models

P systems with active membranes are powerful parallel natural computing models, which were inspired by cell structure and behavior. Inspired by the parallel processing of biological information and with the idealistic assumption that each rule is completed in exactly one time unit, P systems with active membranes are able to solve computational hard problems in a feasible time. However, an important biological fact in living cells is that the execution time of a biochemical reaction cannot be accurately divided equally and completed in one time unit. In this work, we consider time as an important factor for the computation in P systems with active membranes and investigate the computational efficiency of such P systems. Specifically, we present a time-free semiuniform solution to the quantified Boolean satisfiability problem (QSATproblem, for short) in the framework of P systems with active membranes, where the solution to such problem is correct, which does not depend on the execution time for the used rules.

scholarly journals Time-free Solution to Independent Set Problem using P Systems with Active Membranes

2021 ◽  
Vol 182 (3) ◽  
pp. 243-255
Author(s):  
Yu Jin ◽  
Bosheng Song ◽  
Yanyan Li ◽  
Ying Zhu
Keyword(s):  
Membrane Computing ◽  
Independent Set ◽  
P Systems ◽  
Natural Computing ◽  
Free Solution ◽  
Independent Set Problem ◽  
Global Clock ◽  
Active Membranes ◽  
Biological Reality ◽  
Hard Problems

Membrane computing is a branch of natural computing aiming to abstract computing models from the structure and functioning of living cells. The computation models obtained in the field of membrane computing are usually called P systems. P systems have been used to solve computationally hard problems efficiently on the assumption that the execution of each rule is completed in exactly one time-unit (a global clock is assumed for timing and synchronizing the execution of rules). However, in biological reality, different biological processes take different times to be completed, which can also be influenced by many environmental factors. In this work, with this biological reality, we give a time-free solution to independent set problem using P systems with active membranes, which solve the problem independent of the execution time of the involved rules.

scholarly journals Tissue P Systems with Cell Division

2008 ◽  
Vol 3 (3) ◽  
pp. 295 ◽  
Author(s):  
Gheorghe Păun ◽  
Mario J. Perez-Jimenez ◽  
Agustín Riscos-Nunez
Keyword(s):  
Cell Division ◽  
Polynomial Time ◽  
Basic Feature ◽  
P Systems ◽  
Sat Problem ◽  
Active Membranes ◽  
Hard Problems

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 the possibility to solve computationally hard problems in polynomial time; we illustrate this possibility with SAT problem.

scholarly journals An Efficient Simulation of Polynomial-Space Turing Machines by P Systems with Active Membranes

2010 ◽  
pp. 461-478 ◽  
Author(s):  
Andrea Valsecchi ◽  
Antonio E. Porreca ◽  
Alberto Leporati ◽  
Giancarlo Mauri ◽  
Claudio Zandron
Keyword(s):  
P Systems ◽  
Polynomial Space ◽  
Turing Machines ◽  
Efficient Simulation ◽  
Active Membranes

P Systems with Active Membranes, Without Polarizations and Without Dissolution: A Characterization of P

2005 ◽  
pp. 105-116 ◽  
Author(s):  
Miguel A. Gutiérrez-Naranjo ◽  
Mario J. Pérez-Jiménez ◽  
Agustín Riscos-Núñez ◽  
Francisco J. Romero-Campero
Keyword(s):  
P Systems ◽  
Active Membranes

Perturbations of AF-Algebras

1979 ◽  
Vol 31 (5) ◽  
pp. 1012-1016 ◽  
Author(s):  
John Phillips ◽  
Iain Raeburn
Keyword(s):  
Hilbert Space ◽  
Unit Ball ◽  
Von Neumann Algebra ◽  
Unitary Operator ◽  
Affirmative Answer ◽  
Positive Answer ◽  
Von Neumann ◽  
Finite Dimensional ◽  
Image Position ◽  
Af Algebras

Let A and B be C*-algebras acting on a Hilbert space H, and letwhere A1 is the unit ball in A and d(a, B1) denotes the distance of a from B1. We shall consider the following problem: if ‖A – B‖ is sufficiently small, does it follow that there is a unitary operator u such that uAu* = B?Such questions were first considered by Kadison and Kastler in [9], and have received considerable attention. In particular in the case where A is an approximately finite-dimensional (or hyperfinite) von Neumann algebra, the question has an affirmative answer (cf [3], [8], [12]). We shall show that in the case where A and B are approximately finite-dimensional C*-algebras (AF-algebras) the problem also has a positive answer.

Simulation of P Systems with Active Membranes on CUDA

2009 ◽  
Author(s):  
José María Cecilia Canales ◽  
José Manuel García Carrasco ◽  
Ginés David Guerrero Hernandez ◽  
Miguel Ángel Martínez del Amor ◽  
Ignacio Pérez Hurtado de Mendoza ◽  
...  
Keyword(s):  
P Systems ◽  
Active Membranes
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