Cooperative Bacterial Foraging Optimization

Algorithm 2

Pseudocode for CBFO-H.

Stage 1: the original BFO algorithm

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

 For (each chemotactic step 𝑡=1∶𝑁_𝑐^𝑠1)

    For(each bacterium 𝑖=1∶𝑆)

      TUMBLE;

      RUN;

      REPRODUCTION;

      ELIMINATION and DISPERSAL;

    End for

 End for

 PASS the best found solutions of each bacterium to stage 2;

Stage 2: the multi-colony cooperative BFO algorithm using explicit space decomposition

   REINITIALIZE: bacteria positions from the best found solutions and the associate

               run-length unit 𝐶_𝑆.

   SPLIT the whole population into 𝑛/2 separate colonies of 2D vectors;

   For (each chemotactic step 𝑡=1∶𝑁_𝑐^𝑠2)

     For (each colony 𝑗=1∶𝑛/2)

      For (each bacterium 𝑖=1∶𝑆)

        TUMBLE;

        RUN;

        REPRODUCTION;

        ELIMINATION and DISPERSAL;

      End for

      UPDATE the best bacterium replace the 𝑗th component of the overall solution;

     End for

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

               If (𝑡mod𝛽=0)    //𝛽 is user-defined constant.

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

               End if

   End for