Swarm Intelligence

 About

Ants form and maintain a line to their food source by laying a trail of pheromone, i.e. a chemical to which other members of the same species are very sensitive. They deposit a certain amount of pheromone while walking, and each ant prefers to follow a direction rich in pheromone. This enables the ant colony to quickly find the shortest route. The first ants to return should normally be those on the shortest route, so this will be the first to be doubly marked by pheromone (once in each direction). Thus other ants will be more attracted to this route than to longer ones not yet doubly marked, which means it will become even more strongly marked with pheromone. Thus, the shortest route is doubly marked, and more ants will follow it.  This simple model finds the shortest route between the nest and a food source.  Allowing the pheromone trail to "evaporate" (as in nature) provides the ants a mechanism to explore for alternate food sources when the first is depleting and for alternate routes should the first become blocked.

Self Organisation

Self-organisation is a set of dynamical mechanisms whereby structures appear at the global level of a system from interactions among its lower level components.  The rules specifying the interactions among the system’s constituent units are executed based only on local information, without reference to the global pattern.  The global pattern is said to be an emergent property of the system. 

 Abstract

          The behavior of social insects in general, and of ants living in colonies in particular, has fascinated researchers in ethology but also fascinated computer scientists. Many models have been proposed to explain their capabilities.  Swarm intelligence systems have been offered as a novel computational approach that replaces the traditional emphasis on control, preprogramming, and centralization with designs featuring autonomy, emergence, and distributed functioning.

Traveling Sales Ant

          In the traveling salesman problem,a person must find the shortest  route by which to vcisit a given number of cities,each exactly once.The classic problem is devilishly difficult:for just 15 cities there are billions of route possiblities.  Recently researchers have begun to experiment with antlike agents to derive a solution.The approach relies on the artificial ants laying and following equivalent of pheromone trails. Envision a colony of such ants each independently hopping from city to city, favoring nearby locations but otherwise traveling randomly.After completing a tour of all cities, an ant goes back to links it used and deposit pheromone.The amont of chemical is inversely proportional to the overall length of the tour:the shorter distance ,the more pheromone each of the links receives.Thus,after all ants have completed their tour and spread their pheromone,the links that belong to the highest number of short tours will be richest with the chemical.Because the pheromone evaporates, links in long routes will eventually contain significantally less of the substance than those in short tours will.

Technologies  And Swarm Intelligence

          Swarm Intelligence is a design framework based on social insect behavior. Social insects such as ants, bees, and wasps are unique in the way these simple individuals cooperate to accomplish complex, difficult tasks. This cooperation is distributed among the entire population, without any centralized control. Each individual simply follows a small set of rules influenced by locally available information. This emergent behavior results in great achievements that no single member could complete by themselves.