V. Masilamani

Parallel splicing on iso-arrays

In this paper we introduce a new model called iso-picture splicing system, to generate iso-pictures. We compare the family of languages generated by the proposed system with existing family of languages such as local iso-picture languages and we prove some properties of the family of languages generated by proposed system.

Efficient Algorithms for Reconstruction of 2D-Arrays from Extended Parikh Images

The concept of a Parikh matrix or an extended Parikh mapping of words introduced by Mateescu et al (2001) is formulated here for two-dimensional (2D) arrays. A polynomial time algorithm is proposed to reconstruct an unknown 2D-array over { 0,1 } from its image under the extended Parikh mapping along a single direction. On the other hand the problem of reconstructing a 2D-array over { 0,1 } from its image under the extended Parikh mapping along three or more directions is shown to be NP-hard. Also a polynomial time algorithm to reconstruct a 2D-array over {0,1} with a maximum number of ones close to the main diagonal of the array is presented by reducing the problem to Min-cost Max-flow problem.

Accepting H-Array Splicing Systems

In [3], Tom Head defined splicing systems motivated by the behaviour of DNA sequences. The splicing system makes use of a new operation, called splicing on strings of symbols. Paun et al. [7] extended the definition of Head and defined extended H systems which are computationally universal.

A min-cost-max-flow based algorithm for reconstructing binary image from two projections using similar images

The aim of this paper is to study the reconstruction of binary images from two projections using a priori images that are similar to the unknown image. Reconstruction of images from a few projections is preferred to reduce radiation hazards. It is well known that the problem of reconstructing images from a few projections is ill-posed. To handle the ill-posedness of the problem, a priori information such as convexity, connectivity and periodicity are used to limit the number of possible solutions. We use a priori images that are similar to the unknown image, to reduce the class of images having the same two projections. The a priori similar images may be obtained in many ways such as by considering images of neighboring slices or images of the same slice, taken in previous time instances. In this paper, we give a polynomial time algorithm to reconstruct binary image from two projections such that the reconstructed image is optimally close to the a priori similar images. We obtain a solution to our problem by reducing our problem to min cost integral max flow problem.

Accepting H Iso-Array System

In this paper, we introduce the notion of accepting H iso-array system which is defined by a finite set of permitting iso-arrays as a counter part of the well investigated accepting splicing systems defined by Mitrana et al. 2010. We compare the generative power of this system with that of some existing models such as controlled sequential pasting system, regular iso-array grammar, context-free iso-array grammar and study some properties of accepting H iso-array systems.

Iso-Array Splicing Grammar System

Splicing systems were introduced by Head [4] on biological considerations to model certain recombinant behaviour of DNA molecules and are of current interest and study [5]. The splicing systems make use of a new operation called splicing on arrays of symbols [9]. Parallel splicing operation has been recently applied to rectangular arrays [6]. Further Dassow and Mitrana [2] introduced a new type of grammar system called splicing grammar system in which communication is done by splicing of strings. In this paper, we propose a new model called iso-picture splicing grammar system to generate iso-pictures. We compare the iso-picture splicing grammar system with iso-array grammars such as regular iso-array grammar and context free iso-array grammar.