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Showing papers by "Kamala Krithivasan published in 2003"


Journal ArticleDOI
TL;DR: It is shown that P automata characterize the recursively enumerable sets of vectors of natural numbers.
Abstract: In this paper, we propose a class of P automata in which each membrane has a state, like in tissue P systems [5], and the computation starts at some initial state and ends in a final state. Unlike the automaton considered in [2], where rules are used in sequential manner, here we consider a variant such that the rules can be applied in maximal mode (as defined in tissue P systems). We show that P automata characterize the recursively enumerable sets of vectors of natural numbers.

14 citations


Book ChapterDOI
17 Jul 2003
TL;DR: In this article, the capabilities of three approaches that construct P systems for generation of arrays on rectangular grids, to handle arrays on triangular grids, are demonstrated and three approaches for constructing picture grammars for generating hexagonal arrays on a triangular grid are presented.
Abstract: P systems generating rectangular arrays have been recently introduced in [1,2,3], thus bringing together the two areas of theoretical computer science, namely membrane computing and picture grammars In this paper, hexagonal arrays on triangular grids are considered and the capabilities of the three approaches [1,2,3] that construct P systems for generation of arrays on rectangular grids, to handle arrays on triangular grids, are demonstrated

8 citations


Journal Article
TL;DR: It is proved that all these systems accept the family of recursively enumerable languages both in the centralized and in the non-centralized strategies and in both returning and non-returning communication modes with only two components.
Abstract: We consider automata systems consisting of several pushdown automata working in parallel and communicating the contents of their stacks by request. We show that centralized non-returning parallel communicating pushdown automata systems with three components recognize all recursively enumerable languages. We also show that centralized returning pushdown automata systems accept non-ET0L languages. We study two variants of communication: one uses filters in communication and in the other only specified number of symbols are communicated. We prove that all these systems accept the family of recursively enumerable languages both in the centralized and in the non-centralized strategies and in both returning and non-returning communication modes with only two components.

7 citations


Journal ArticleDOI
TL;DR: This paper builds the theory of distributed ω-automata for finite state automata and pushdown automata in different modes of cooperation like the t-mode, *- Mode, = k- mode, ≤ k- Mode and ≥ k-mode along with different acceptance criteria, and gives proofs for the equivalence of all modes of Cooperation and acceptance criteria in the case of distributedω-pushdown automATA.
Abstract: In this paper, we introduce the notion of distributed ω-automata. Distributed ω-automata are a group of automata working in unison to accept an ω-language. We build the theory of distributed ω-automata for finite state automata and pushdown automata in different modes of cooperation like the t-mode, *-mode, = k-mode, ≤ k-mode and ≥ k-mode along with different acceptance criteria i.e. Buchi-, Muller-, Rabin- and Streett- acceptance criteria. We then analyze the acceptance power of such automata in all the above modes of cooperation and acceptance criteria. We present proofs that distributed ω-finite state automata do not have any additional power over ω-finite state automata in any of the modes of cooperation or acceptance criteria, while distributed ω-pushdown automata can accept languages not in CFLω. We give proofs for the equivalence of all modes of cooperation and acceptance criteria in the case of distributed ω-pushdown automata. We show that the power of distributed ω-pushdown automata is equal to that of ω-Turing Machines. We also study the deterministic version of distributed ω-pushdown automata. Deterministic ω-pushdown automata accept only languages contained in CFLω but distributed deterministic ω-pushdown automata can accept languages not in CFLω and have the same power as their nondeterministic counterparts. We also define distributed completely deterministic ω-pushdown automata and analyze their power.

Book ChapterDOI
TL;DR: A theoretical model for performing gate operations – OR, AND, and NOT – using peptide-antibody interactions is proposed and extended to further gates, such as XOR, NAND, and NOR.
Abstract: We propose a theoretical model for performing gate operations – OR, AND, and NOT – using peptide-antibody interactions The idea is extended to further gates, such as XOR, NAND, and NOR