Lévy-Flight Krill Herd Algorithm

Algorithm 2

Lévy-flight krill herd algorithm.

Begin

  Step 𝟏: Initialization. Set the generation counter 𝑡=1; initialize the population 𝑃 of NP

     krill individuals randomly and each krill corresponds to a potential solution to

     the given problem; set the foraging speed 𝑉_𝑓, the maximum diffusion speed

     𝐷^max, and the maximum induced speed 𝑁^max; set max Lévy flight step size 𝐴

     and elitism parameter

     KEEP: how many of the best krill to keep from one generation to the next.

  Step 𝟐: Fitness evaluation. Evaluate each krill individual according to its position.

  Step 𝟑: While the termination criteria is not satisfied or t < MaxGeneration do

      Sort the population/krill from best to worst.

      Store the KEEP best krill as KEEPKRILL.

       for 𝑖=1 : NP (all krill) do

        Perform the following motion calculation.

           Motion induced by the presence of other individuals

           Foraging motion

           Physical diffusion

        Update the krill individual position in the search space by (6).

        Fine-tune 𝑋_𝑡+1 by performing LLF operator as shown in Algorithm 1.

        Evaluate each krill individual according to its new position 𝑋_𝑡+1.

       end for 𝑖

      Replace the KEEP worst krill with the KEEP best krill stored in KEEPKRILL.

      Sort the population/krill from best to worst and find the current best.

       𝑡=𝑡+1;

  Step 𝟒: end while

  Step 𝟓: Post-processing the results and visualization.

End.