250 research outputs found

    On the power of parallel communicating Watson–Crick automata systems

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    AbstractParallel communicating Watson–Crick automata systems were introduced in [E. Czeizler, E. Czeizler, Parallel communicating Watson–Crick automata systems, in: Z. Ésik, Z. FĂŒlöp (Eds.), Proc. Automata and Formal Languages, DobogĂłkƑ, Hungary, 2005, pp. 83–96] as possible models of DNA computations. This combination of Watson–Crick automata and parallel communicating systems comes as a natural extension due to the new developments in DNA manipulation techniques. It is already known, see [D. Kuske, P. Weigel, The Role of the Complementarity Relation in Watson–Crick Automata and Sticker Systems, DLT 2004, Lecture Notes in Computer Science, Vol. 3340, Auckland, New Zealand, 2004, pp. 272–283], that for Watson–Crick finite automata, the complementarity relation plays no active role. However, this is not the case when considering parallel communicating Watson–Crick automata systems. In this paper we prove that non-injective complementarity relations increase the accepting power of these systems. We also prove that although Watson–Crick automata are equivalent to two-head finite automata, this equivalence is not preserved when comparing parallel communicating Watson–Crick automata systems and multi-head finite automata

    BiolĂłgiai indĂ­ttatĂĄsĂș kiszĂĄmĂ­tĂĄs: formĂĄlis nyelvi modellek = Bio-inspired computation: formal language theoretic models

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    A biolĂłgiai indĂ­ttatĂĄsĂș nyelvprocesszor hĂĄlĂłzatok terĂŒletĂ©n megmutattuk, hogy az elemi evolĂșciĂłs processzorokbĂłl ĂĄllĂł hibrid hĂĄlĂłzatok a Turing gĂ©pekkel egyenlƑ szĂĄmĂ­tĂĄsi erejƱ eszközök. BebizonyĂ­tottuk, hogy minden, azonos ĂĄbĂ©cĂ© feletti rekurzĂ­ven felsorolhatĂł nyelv elƑállĂ­thatĂł nem elemi evolĂșciĂłs processzorok hasonlĂł architektĂșrĂĄjĂș hibrid hĂĄlĂłzatĂĄval. Az evolĂșciĂłs processzorok kizĂĄrĂłlagosan egy elemi genetikai mƱvelet, azaz beszĂșrĂĄs, törlĂ©s vagy betƱcsere elvĂ©gzĂ©sĂ©re alkalmas eszközök. A membrĂĄn rendszerek elmĂ©letĂ©ben megmutattuk, hogy a P automatĂĄk, amelyek kizĂĄrĂłlag kommunikĂĄciĂłra Ă©pĂŒlƑ elfogadĂł membrĂĄn rendszerek, szabĂĄlyaik maximĂĄlisan pĂĄrhuzamos mĂłdĂș hasznĂĄlata esetĂ©n a környezetfĂŒggƑ nyelvek osztĂĄlyĂĄt, mĂ­g a szabĂĄlyaik szekvenciĂĄlis mĂłdĂș hasznĂĄlata esetĂ©n egy, a logaritmikusnĂĄl kisebb tĂĄrigĂ©nyƱ nyelvosztĂĄlyt hatĂĄroznak meg. A P rendszerek több fontos vĂĄltozatĂĄrĂłl megmutattuk, hogy a Turing gĂ©pekĂ©vel egyenlƑ szĂĄmĂ­tĂĄsi erejƱ, mĂ©g bizonyos mĂ©retparamĂ©tereinek korlĂĄtozĂĄsa esetĂ©n is. A molekulĂĄris szĂĄmĂ­tĂĄstudomĂĄny terĂŒletĂ©n megmutattuk a Watson-Crick komplementaritĂĄs elvĂ©re Ă©pĂŒlƑ Ășn. kiterjesztett standard Watson-Crick D0L rendszerek hĂĄlĂłzatainak a Turing gĂ©pekĂ©vel valĂł egyenlƑ szĂĄmĂ­tĂĄsi erejĂ©t nem teljes informĂĄciĂł közvetĂ­tĂ©sĂ©nek lehetƑsĂ©ge esetĂ©n is. | In the area of bio-inspired language processors, we proved that hibrid networks of elementary evolutionary processors are computationally complete and these networks with non-elementary components are able to determine any recursively enumerable language over the same alphabet with a similar underlying graph structure. Evolutionary processors are language determining devices capable of performing only one type of point mutations (insertion, deletion, replacement). In the theory of membrane (P) systems, we proved that P automata, i.e. accepting, purely communicating membrane systems, by applying their rules in the maximally parallel manner determine the class of context-sensitive languages and by using their rules sequentially identify a class of languages strictly included in the class of languages computable by Turing machines with a logarithmically bounded workspace. For several important variants of P systems, we proved that they are computationally complete, even if they are bounded in some of their size parameters. In the area of molecular computing, we proved that networks of extended standard Watson-Crick D0L systems, models which make use of Watson-Crick complementarity, with the possibility of incomplete information communication are computationally complete

    Acta Cybernetica : Volume 17. Number 4.

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    Measuring Communication in Parallel Communicating Finite Automata

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    Systems of deterministic finite automata communicating by sending their states upon request are investigated, when the amount of communication is restricted. The computational power and decidability properties are studied for the case of returning centralized systems, when the number of necessary communications during the computations of the system is bounded by a function depending on the length of the input. It is proved that an infinite hierarchy of language families exists, depending on the number of messages sent during their most economical recognitions. Moreover, several properties are shown to be not semi-decidable for the systems under consideration.Comment: In Proceedings AFL 2014, arXiv:1405.527

    Reversible Two-Party Computations

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    Deterministic synchronous systems consisting of two finite automata running in opposite directions on a shared read-only input are studied with respect to their ability to perform reversible computations, which means that the automata are also backward deterministic and, thus, are able to uniquely step the computation back and forth. We study the computational capacity of such devices and obtain on the one hand that there are regular languages that cannot be accepted by such systems. On the other hand, such systems can accept even non-semilinear languages. Since the systems communicate by sending messages, we consider also systems where the number of messages sent during a computation is restricted. We obtain a finite hierarchy with respect to the allowed amount of communication inside the reversible classes and separations to general, not necessarily reversible, classes. Finally, we study closure properties and decidability questions and obtain that the questions of emptiness, finiteness, inclusion, and equivalence are not semidecidable if a superlogarithmic amount of communication is allowed.Comment: In Proceedings AFL 2023, arXiv:2309.0112

    Watson–Crick context-free grammars: Grammar simpliïŹcations and a parsing algorithm

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    A Watson–Crick (WK) context-free grammar, a context-free grammar with productions whose right-hand sides contain nonterminals and double-stranded terminal strings, generates complete double-stranded strings under Watson–Crick complementarity. In this paper, we investigate the simpliïŹcation processes of Watson–Crick context-free grammars, which lead to deïŹning Chomsky like normal form for Watson–Crick context-free grammars. The main result of the paper is a modiïŹed CYK (Cocke–Younger–Kasami) algorithm for Watson–Crick context-free grammars in WK-Chomsky normal form, allowing to parse double-stranded strings in O(n^6) time

    On the Languages Accepted by Watson-Crick Finite Automata with Delays

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    [EN] In this work, we analyze the computational power of Watson-Crick finite automata (WKFA) if some restrictions over the transition function in the model are imposed. We consider that the restrictions imposed refer to the maximum length difference between the two input strands which is called the delay. We prove that the language class accepted by WKFA with such restrictions is a proper subclass of the languages accepted by arbitrary WKFA in general. In addition, we initiate the study of the language classes characterized by WKFAs with bounded delays. We prove some of the results by means of various relationships between WKFA and sticker systems.This work has been developed with the financial support of the European Union's Horizon 2020 research and innovation programme under grant agreement No. 952215 corresponding to the TAILOR project.Sempere Luna, JM. (2021). On the Languages Accepted by Watson-Crick Finite Automata with Delays. Mathematics. 9(8):1-12. https://doi.org/10.3390/math9080813S1129
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