Showing papers by "Kamala Krithivasan published in 1992"
TL;DR: In this paper, the recognition capabilities of CA and TVCA are compared, and the power of this implicit query mechanism is compared with the traditional oracle access in Turing machines.
Abstract: Cellular automata (CA) are parallel language recognition devices. In this paper, the notion of a time-varying CA (TVCA) is introduced. In a TVCA, the transition function can vary with time, and the variation is controlled by a prespecified language. This language can be viewed as an oracle to which the TVCA makes implicit queries; thus TVCA provide a mechanism for defining relativised CA. In this paper, the recognition capabilities of CA and TVCA are compared. TVCA as relativised CA are formalised, and the power of this implicit query mechanism is compared with the traditional oracle access in Turing machines.
7 citations
TL;DR: This paper presents efficient parallel algorithms for the maximum empty rectangle problem on crew pram and anO(logn) time algorithm on a mesh-of-trees architecture.
Abstract: We present efficient parallel algorithms for the maximum empty rectangle problem in this paper. On crew pram, we solve the area version of this problem inO(log 2 n) time usingO(nlogn) processors. The perimeter version of this problem is solved inO(logn) time usingO(nlog 2 n) processors. On erew pram, we solve both the problems inO(logn) time usingO(n 2/logn) processors. We also present anO(logn) time algorithm on a mesh-of-trees architecture.
3 citations
01 Jan 1992
TL;DR: This paper presents “forgetful” L systems as a new variant of the classical L systems, in which apart from the state of a cell, its ancestry is also allowed to influence its future development.
Abstract: This paper presents “forgetful” L systems as a new variant of the classical L systems. In this variant, apart from the state of a cell, its ancestry is also allowed to influence its future development. A cell in a particular state will, depending on its ancestry, remember either all rules or only special marked rules. Such systems are compared with the nonforgetful L systems. Various decidability issues are considered and some closure properties are presented. These systems attempt to provide a more realistic model for modelling certain developmental processes.