Cooperative Bacterial Foraging Optimization

Algorithm 1

Pseudocode for CBFO-S.

INITIALIZE: the position and the associated run-length unit C_initial of the bacteria colony;

  For(each phase 𝑘=1∶𝑁_p)

          For(each chemotactic step 𝑡=1∶𝑁_c)

        For(each bacterium 𝑖=1∶𝑆)

           Calculate the fitness 𝐽^𝑖(𝑡,𝑘) of 𝑖th bacterium;

           TUMBLE: Generate a random vector Δ, where each element belongs to [−1,1].

                Move the bacterium i in the direction of Δ0𝑥02215Δ^𝑇Δ by a unit     

                walk of size 𝐶(𝑘). Then calculate the new fitness

                 𝐽_𝑖(𝑡+1,𝑘) of bacterium 𝑖;

           Set  flag = 0;

           RUN: While (flag <𝑁_𝑠)

                If (𝐽_𝑖(𝑡+1,𝑘)<𝐽_𝑖(𝑡,𝑘))

                   Take another unit walk in the same direction;

                    Calculate the new fitness as 𝐽_𝑖(𝑡+1,𝑘);

                    flag = flag + 1;

                End if

                End while

        End for

         REPRODUCTION: The 𝑆/2 bacteria with the worst fitness die and the

                      other 𝑆/2 bacteria with the best fitness split;

         ELIMINATION and DISPERSAL: With probability 𝑝_𝑒𝑑, eliminate and

                                           disperse each bacterium;

          End for

           REINITIALIZE: bacteria positions from the potential candidate positions

                        found by each bacterium in the phase 𝑘.

           EVOLUTION: Evolution is added to run-length unit by:

              𝐶(𝑘+1)=𝐶(𝑘)/𝛼;//𝛼 is user-defined constant.

  End for