Cuckoo Search Algorithm

What is Cuckoo Search Algorithm?

Cuckoo search is an optimization algorithm used in Natural Language Processing. It was inspired by the obligate brood parasitism of some cuckoo species by laying their eggs in the nests of host birds of other species. Some host birds can engage direct conflict with the intruding cuckoos. 

For example, if a host bird discovers the eggs are not their own, it will either throw these alien eggs away or simply abandon its nest and build a new nest elsewhere. Cuckoo search idealized such breeding behavior, and thus can be applied for various optimization problems. It has been shown that cuckoo search is a special case of the well-known (μ + λ)-evolution strategy.

Cuckoo search (CS) uses the following representations:

Each egg in a nest represents a solution, and a cuckoo egg represents a new solution. The aim is to use the new and potentially better solutions (cuckoos) to replace a not-so-good solution in the nests. In the simplest form, each nest has one egg. The algorithm can be extended to more complicated cases in which each nest has multiple eggs representing a set of solutions.

CS is based on three idealized rules:

• Each cuckoo lays one egg at a time, and dumps its egg in a randomly chosen nest.

• The best nests with high quality of eggs will carry over to the next generation.

• The number of available hosts nests is fixed, and the egg laid by a cuckoo is discovered by the host bird with a probability in range (0,1) . In this case, the host bird can throw the egg away/abandon the nest, and build a completely new nest.

How to Improve Cuckoo Search Algorithm:

Convergence of Cuckoo Search algorithm can be substantially improved by genetically replacing abandoned nests (instead of using the random replacements from the original method). Modifications to the algorithm have also been made by additional interbreeding of best (high quality) nests  and this approach has been successfully applied to a range of industrial optimization problems.