6 research outputs found
Introducing a Space Complexity Measure for P Systems
We define space complexity classes in the framework of membrane computing, giving some initial results about their mutual relations and their connection with time
complexity classes, and identifying some potentially interesting problems which require
further research
Space complexity equivalence of P systems with active membranes and Turing machines
We prove that arbitrary single-tape Turing machines can be simulated by uniform families of P systems with active membranes with a cubic slowdown and quadratic space overhead. This result is the culmination of a series of previous partial results, finally establishing the equivalence (up to a polynomial) of many space complexity classes defined in terms of P systems and Turing machines. The equivalence we obtained also allows a number of classic computational complexity theorems, such as Savitch's theorem and the space hierarchy theorem, to be directly translated into statements about membrane systems
Non-confluence in divisionless P systems with active membranes
AbstractWe describe a solution to the SAT problem via non-confluent P systems with active membranes, without using membrane division rules. Furthermore, we provide an algorithm for simulating such devices on a nondeterministic Turing machine with a polynomial slowdown. Together, these results prove that the complexity class of problems solvable non-confluently and in polynomial time by this kind of P system is exactly the class NP