Smaller Search Space Research Articles

A Framework for Multiresolution Optimization in a Parallel/Distributed Environment: Simulation of Hierarchical GAs

A novel framework for multi-resolution optimization methodology is developed for parallel/distributed simulation environments. The architecture is constructed with multiple clusters hierarchically arranged with each level solving different degrees of abstracted problems. Creation and deletion of clusters are executed dynamically during the search operation. A higher level cluster evaluates a wider search space with low resolution, whereas a lower level cluster investigates a smaller search space which is more promising for containing the global optimum. Each cluster consists of acontroller(expert system) andagents(GA), where the agents evaluate the parameters of the problem of variable structure which allocates more computing resources to promising search subspaces. This article describes the prototyping of thehierarchical distributed genetic algorithms(HDGA) in an object-oriented simulation environment and provides preliminary experimental results. The results are promising, and many theoretical questions concerning robustness of the approach are raised for future research.

An efficient algorithm to search for minimal closed covers in sequential machines

The removal of redundant states in a finite state machine (FSM) is essential to reducing the complexity of a sequential circuit. An efficient algorithm for state minimization in incompletely specified state machines is presented. This algorithm employs a tight lower bound and a fail-first heuristic and generates a relatively small search space from the prime compatibles. It utilizes efficient pruning rules to further reduce the search space and finds a minimal closed cover. The technique guarantees the elimination of all the redundant states in a very short execution time. Experimental results with a large number of FSMs including the MCNC FSM benchmarks are presented. The results are compared with other work in this area.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>