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Showing papers by "Kamala Krithivasan published in 2004"


Journal ArticleDOI
TL;DR: The relation between external arrays contextual P systems and external array contextual grammars with regular control is obtained and some properties of these systems are discussed.
Abstract: We define external and internal array contextual P systems, which generate rectangular arrays. We also introduce external array contextual P systems with erased contexts. Some properties of these systems are discussed. We obtain the relation between external array contextual P systems and external array contextual grammars with regular control.

18 citations


Journal ArticleDOI
TL;DR: In this article, a theoretical model for representing and manipulating binary numbers using peptide-antibody interactions is proposed, and the number of steps is independent of the size of the numbers.
Abstract: We propose a theoretical model for representing and manipulating binary numbers using peptide-antibody interactions. In particular, we present models to solve simple binary arithmetical problems like addition and subtraction. As the interactions can take place in parallel we show that the number of steps is independent of the size (bits) of the numbers.

9 citations


Book ChapterDOI
01 Dec 2004
TL;DR: Hexagonal tiling systems, hexagonal local picture languages and hexagonal recognizable picture languages are defined and xyz-domino systems describe rectangular arrays and characterize hexagonal picture languages using this.
Abstract: Hexagonal tiling systems, hexagonal local picture languages and hexagonal recognizable picture languages are defined in this paper. Hexagonal Wang tiles and systems are also introduced. It is noticed that the family of hexagonal picture languages defined by hexagonal Wang systems coincides with the family of hexagonal picture languages recognized by hexagonal tiling system. Similar to hv-domino systems describing rectangular arrays, we define xyz-domino systems and characterize hexagonal picture languages using this. Unary hexagonal picture languages are also considered and we analyze some of their properties.

8 citations


Journal Article
TL;DR: The computational efficiency of rewriting tissue P systems is shown by solving the Satisfiability and the Hamiltonian path problems in linear time and it is shown that rewriting tissueP systems with at most two cells and four states are computationally universal.
Abstract: By considering string-objects and rewriting rules, we propose a variant of tissue P systems, namely, rewriting tissue P systems We show the computational efficiency of rewriting tissue P systems by solving the Satisfiability and the Hamiltonian path problems in linear time We study the computational capacity of rewriting tissue P systems and show that rewriting tissue P systems with at most two cells and four states are computationally universal We also show the universality result of rewriting tissue P systems with at most one cell and five states Finally we propose some new directions for future work

4 citations


Journal Article
TL;DR: 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.
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.

3 citations


Journal ArticleDOI
TL;DR: In this article, the authors consider the problem of separating a collection of isothetic polygons in the plane by translating one polygon at a time to infinity, where the directions of translation are the four isothetic (parallel to the axes) directions and a particular polygon can be translated only in one of these four directions.

2 citations


Journal Article
TL;DR: A new type of regulation on the derivation of a context-free grammar is proposed: the productions used for passing from a level of a derivation tree to the next level should have the right-hand members of the same length.
Abstract: We propose a new type of regulation on the derivation of a context-free grammar: the productions used for passing from a level of a derivation tree to the next level should have the right-hand members of the same length. We prove that such length synchronized context-free grammars characterize the family of ETOL languages, and therefore are equivalent with the synchronization context-free grammars of H. Juirgensen and K. Salomaa. In this way, a conjecture of H. Jurgensen and K. Salomaa is disproved, about a language which was conjectured not to be generated by a synchronization context-free grammar.

2 citations