Multi-swarm that learns

This paper studies particle swarm optimization approach enriched by two versions of an extension aimed at gathering information during the optimization process. Application of these extensions, called memory mechanisms, increases computational cost, but it is spent to a benefit by incorporating the knowledge about the problem into the algorithm and this way improving its search abilities. The first mechanism is based on the idea of storing explicit solutions while the second one applies one-pass clustering algorithm to build clusters containing search experiences. The main disadvantage of the former mechanism is lack of good rules for identification of outdated solutions among the remembered ones and as a consequence unlimited growth of the memory structures as the optimization process goes. The latter mechanism uses other form of knowledge representation and thus allows us to control the amount of allocated resources more efficiently than the former one. Both mechanisms have been experimentally verified and their advantages and disadvantages in application for different types of optimized environments are discussed.