Modular Completeness for Communication Closed Layers

The Communication Closed Layers law is shown to be modular complete for a model related to that of Mazurkiewicz. It is shown that in a modular style of program development the CCL rule cannot be derived from simpler ones. Within a non-modular set-up the CCL rule can be derived however from a simpler independence rule and an analog of the expansion rule for process algebras.\ud Part of this work has been supported by Esprit/BRA Project 6021 (REACT)

Efficient Passive Clustering and Gateways selection MANETs

Passive clustering does not employ control packets to collect topological information in ad hoc networks. In our proposal, we avoid making frequent changes in cluster architecture due to repeated election and re-election of cluster heads and gateways. Our primary objective has been to make Passive Clustering more practical by employing optimal number of gateways and reduce the number of rebroadcast packets

Layering techniques for development of parallel systems: An algebraic approach

A process language is presented which makes a clear distinction between temporal order and causal order. This allows for several algebraic laws that are particularly interesting for the design of concurrent systems. One of these is an algebraic formulation of the communication closed layers principle by [EF82]. These laws suffice to rewrite process terms that avoid specification of temporal ordering into a unique normal form. Other transformations allow for gradually imposing temporal ordering on an already functionally correct design. The combination of such laws enables a design strategy where architecture independent designs are transformed towards a form that matches a particular implementation architecture. We apply this style of design to various distributed algorithms, including an algorithm for the “point-in-polygon” problem transformed to a form suitable for pipelined execution on a tree network, and the Floyd-Warshall algorithm for the all-points shortest path transformed to a form suitable for execution on a SIMD architecture