Osztott modellek a molekuláris számítástudományban = Distributed models of molecular computation

A vizsgálódások tárgyai olyan, biokémiai folyamatokat modellező vagy biokémiai folyamatok által inspirált működési elvű számítástudományi eszközök, számítási modellek voltak, melyek fő jellemzője az osztott és párhuzamos működés. A projekt célja volt a molekuláris számítások természetének, a modellek sajátosságainak jobban megfelelő szempontok figyelembe vétele, ezáltal esetleg a biokémiai folyamatok jobb megértése, illetve a formális nyelvek és automaták elméletének továbbfejlesztése, eszköztárának bővítése a biokémiai folyamatok és az osztott modellek által inspirált irányba. Vizsgálódásaink kiterjedtek a DNS rekombináció motiválta számítási eszközök mellett a membrán rendszerek területére, különös tekintettel a membrán automatákra. A kutatás során vizsgáltuk új működési módok tulajdonságait és az ezekből levonható következtetéseket, eredményeket értünk el bizonyos modellek méret-bonyolultságának vizsgálata illetve a formális nyelv fogalmának végtelen ábécére való kiterjesztése terén. | Our research concentrated on computational models which are not only based on or inspired by natural, mostly biochemical processes, but work in a distributed and parallel manner. The aim of the project was to investigate and identify those important aspects and special properties describing the nature of molecular computation which might not only help to better understand natural processes, but could also contribute to the extension of the theory of formal languages and automata by introducing new tools and techniques in a nature inspired, nature motivated way. Our investigations not only concerned computational models based on DNA recombination, but also membrane systems and membrane automata. We investigated new modes of operation of existing models, obtained results about the descriptional (size) complexity of certain devices, and about extending the notion of formal language to infinite alphabets

A Class of P Automata for Characterizing Context-free Languages

We present a characterization of context-free languages in terms of a restricted class of P automata (P systems accepting strings of symbols using symport/antiport communication rules). The characterization is based on the form of the rules used by the system

A Note on a New Class of APCol Systems

We introduce a new acceptance mode for APCol systems (Automaton-like P colonies), variants of P colonies where the environment of the agents is given by a string and during functioning the agents change their own states and process the string similarly to automata. In case of the standard variant, the string is accepted if it can be reduced to the empty word. In this paper, we de ne APCol systems where the agents verify their environment, a model resembling multihead nite automata. In this case, a string of length n is accepted if during every halting computation the length of the environmental string in the con gurations does not change and in the course of the computation every agent applies a rule to a symbol on position i of some of the environmental strings for every i, 1 < i < n at least once. We show that these verifying APCol systems simulate one-way multihead nite automata

P Colony Automata with LL(k)-like Conditions

We investigate the possibility of the deterministic parsing (that is, parsing without backtracking) of languages characterized by (generalized) P colony automata. We de ne a class of P colony automata satisfying a property which resembles the LL(k) property of context-free grammars, and study the possibility of parsing the characterized languages using a k symbol lookahead, as in the LL(k) parsing method for context-free languages

The DBSCAN Clustering Algorithm on P Systems

We show how to implement the DBSCAN clustering algorithm (Density Based Spatial Clustering of Applications with Noise) on membrane systems using evolution rules with promoters and priorities

Describing Membrane Computations with a Chemical Calculus

Membrane systems are nature motivated computational models inspired by certain basic features of biological cells and their membranes. They are examples of the chemical computational paradigm which describes computation in terms of chemical solutions where molecules interact according to rules de ning their reaction capabilities. Chemical models can be presented by rewriting systems based on multiset manipulations, and they are usually given as a kind of chemical calculus which might also allow nondeterministic and non-sequential computations. Here we study membrane systems from the point of view of the chemical computing paradigm and show how computations of membrane systems can be described by such a chemical calculus

On the Classes of Languages Characterized by Generalized P Colony Automata

We study the computational power of generalized P colony automata and show how it is in uenced by the capacity of the system (the number of objects inside the cells of the colony) and the types of programs which are allowed to be used (restricted and unrestricted com-tape and all-tape programs, or programs allowing any kinds of rules)