Читать книгу Power Magnetic Devices - Scott D. Sudhoff - Страница 31

In biological populations, it sometimes occurs that a population becomes geographically dispersed, and then members of these geographically isolated regions continue to evolve on separate evolutionary tracks. Sometimes, because of storms or random events, a few members of one region migrate into another region. These individuals then have children with members of the region which they have migrated into, often yielding very fit offspring.

It is possible to create GAs where such migration occurs. In such a GA, each individual is associated with a region, and for the most part, only individuals within a given region interact. Each region acts as a separate population. Occasionally, however, a few individuals are transferred between regions.

At first consideration, one might conclude that incorporating such behavior would have little effect on the algorithm. However, in Sudhoff [7] it is shown that at least in the case of one motor design example, the migration operator had a profound effect on the performance of the algorithm. That paper included a comparison between GA optimization and particle swarm optimization, and it found that choice of algorithm was less important than the use of migration in the GA or a somewhat analogous feature known as neighborhoods in particle swarm optimization.