Kamala Krithivasan

Bio: Kamala Krithivasan is an academic researcher from Indian Institute of Technology Madras. The author has contributed to research in topics: Automata theory & Context-sensitive grammar. The author has an hindex of 14, co-authored 122 publications receiving 696 citations. Previous affiliations of Kamala Krithivasan include Madras Christian College & Indian Institutes of Technology.

On the Relative Expressive Power of Contextual Grammars with Maximal and Depth-First Derivations

Abstract: In the recent years, several new classes of contextual grammars have been introduced to give an appropriate model description to natural languages. With this aim, some new families of contextual languages have been introduced based on maximal and depth-first conditions and analyzed in the framework of so-called mildly context sensitive languages. However, the relationship among these families of languages have not yet been analyzed in detail. In this paper, we investigate the relationship between the families of languages whose grammars are based on maximal and depth-first conditions. We prove an interesting result that all these families of languages are incomparable to each other, but they are not disjoint.

Simplified simple H systems

Abstract: In this paper we define restricted versions of simple H systems of type (1,3) and (1,4) and show that the generative power is not decreased by this restriction. In the case of these systems the power is not increased by having a target alphabet whereas having permitting context increases the power.

Visibility of rectagular objects in L 1 metric

Abstract: Given a set of n rectangles (2-dimensional) parallel to xy-plane, and a point P(x,y,z) in 3-dimensional space, we find the visibility of all rectangles i.e., the set of all visible points of rectangles from P in L 1 metric, in O(n 4) time and O(n 3) space. We also discuss the cases where the point P moves along a straight line and the rectangles are inserted and deleted dynamically.

Intersection removal for simple polygons

Abstract: Given two intersecting simple polygons A and B and a direction, θ, we have to find the minimum distance by which B should be translated along direction θ so that A and B no longer intersect. We present two algorithms for this problem for the case that A and B are in 2 dimensions and one algorithm for the case that they are in 3 dimensions. The 2 dimensional algorithms run in O(N 4) and O(N 3 log N) time respectively where N is the total number of vertices in both the polygons while the 3 dimensional algorithm runs in O(N 4) time.

Universality Results for Some Variants of P Systems

Abstract: P systems, introduced by Gh. P?un, form a new class of distributed computing models. Many variants of P systems were shown to be computationally universal. In this paper, we consider several classes of P systems with symbol-objects where we allow the catalysts to move in and out of a membrane. We prove universality results for these variants of P systems with a very small number of membranes.

The Book of L

Abstract: Investigations into Drosophila Wing Development - Results from a Lindenmayer Model.- Fibonacci Words - A Survey.- Planar Map Generation by Parallel Binary Fission/Fusion Grammars.- Modular Trellises.- A New Proof for the DOL Sequence Equivalence Problem and its Implications.- On Compound Lindenmayer Systems.- Graph Grammars with Application Conditions.- The ETOL Hierarchy is in the OI Hierarchy.- Polyhedral Cell Shapes.- On Cyclically Overlap-Free Words in Binary Alphabets.- The Theoretical Basis of the Transplantation Experiment.- Fixed and Stationary ?-Words and ?-Languages.- DOL Schemes and Recurrent Words.- Stochastic OL Systems and Formal Power Series.- Complexity of L-Systems.- Compartmental Hybrid State Production-Diffusion Systems with Application to Prestalk-Prespore Pattern Regulation in Cellular Slime Molds.- Hierarchical Aspects of Plant Development.- Rule Trees Represent Derivations in Edge Replacement Systems.- Languages Defined by Indian Parallel Systems.- L Systems and NLOG-Reductions.- The Parikh-Boundedness of ETOL Languages of Finite Index.- Computer Networks with Compact Routing Tables.- Unconventional Leaves.- A Uniform Model for the Growth of Biological Organisms: Cooperating Sequential Processes.- Graph Technology Applied to a Software Project.- Some Systems for Map Generation.- A Programming Language for Lindenmayer Systems.- A Note on Significance of Cellular Interaction in L-System.- EOL Grammars and Search Trees.- Variation in Inflorescence Structure in Cotoneaster Franchetti.- Partial Path Groups and Parallel Graph Contractions.- When L was Young.- Equivalence Problems for Regular Sets of Word Morphisms.- Parentheses Grammars and Lindenmayer Grammars.- Array Languages and Lindenmayer Systems - A Survey.- Symmetric Distributed Termination.- Development, Growth and Time.- On the Set of all Subgraphs of the Graphs in a Boundary NLC Graph Language.- Graph-Controlled Systems - An Extension of OL Systems.

Introduction to Membrane Computing

Abstract: This is a comprehensive (and friendly) introduction to membrane computing (MC), meant to offer both computer scientists and non-computer scientists an up-to-date overview of the field. That is why the set of notions introduced here is rather large, but the presentation is informal, without proofs and with rigorous definitions given only for the basic types of P systems — symbol object P systems with multiset rewriting rules, systems with symport/antiport rules, systems with string objects, tissue-like P systems, and neural-like P systems. Besides a list of (biologically inspired or mathematically motivated) ingredients/features which can be used in systems of these types, we also mention a series of results, as well as a series of research trends and topics.