Behavior of Interconnected Subpopulations: Genetic Algorithms in a SIMD Environment

The algorithmic form of GAs conforms well to SIMD computing environments with relatively minor adjustments to the operators. The question of the degree to which control parameters affecting intercommunication impact performance is addressed using ANOVA methods. The purpose is to supplant anecdotal experience with statistical evidence. A set of control parameters ---topology, migration operator, migration radius, and migration probability--- were chosen together with four representative levels of each. Metrics for three response variables ---efficiency, diversity, and schema propagation--- were developed that allowed insight into the behavior under the various parametric conditions. These were incorporated into three 4 \Theta 4 \Theta 4 \Theta 4 randomized factorial experiment designs. Among other things, it was determined that the interconnection topology is not in itself a significant factor but the extent of connectivity and frequency of communication are. The experiment confirms muc..

Genetic Algorithms for Scene Interpretation from Prototypical Semantic Description

Use of a genetic algorithm assumes the existence of a figure of merit called fitness, for which there is a value for every candidate solution. The fitness must be measurable over the representation of the solution by means of a computable function. The fitness function is, in most cases, independent of the other factors, including the algorithm used. Often, the fitness is an estimation of the nearness to an ideal solution or the distance from a default solution. In image scene interpretation, the solution takes the form of a set of labels corresponding to the components of an image and its fitness is difficult to conceptualize in terms of distance from a default or nearness to an ideal. Here we describe a model in which a semantic net is used to capture the salient properties of an ideal labeling. Instantiating the nodes of the semantic net with the labels from a candidate solution (a chromosome) provides a basis for estimating a logical distance from a norm. This domain-independent mo..