Research Article

Hybrid Biogeography Based Optimization for Constrained Numerical and Engineering Optimization

Algorithm 4

Hybrid biogeography based optimization.
Generate the initial population POP and vector of mutation scaling factors;
Evaluate the fitness and constraint violations of each individual in POP;
For each generation do
 Sort the individuals in POP based on Deb’s feasibility-based rule (better in front);
 For each one in POP’s first half
   Get two new individuals by two DE mutation strategies (rand/1, rand to best/1);
   Evaluate the fitness value and constraint violations of these two new individuals;
   Among these two new individuals and corresponding parent individual, the best one is stored into population
   Tempbest;
 End for
 Update the vector of prior probability;
 For each one in the first half of POP
   Generate a new individual by Algorithm 1, and store it into population Island;
 End for
 For each one in the first half of POP
   Get one offspring by Algorithm 3 and replace the corresponding individual in population Island with it;
 End for
 Go on chaotic search for the first half of POP and the new individuals generated are stored into population tempIsland;
 Make a contrast between the corresponding ones in Island and tempIsland, and the first half of POP, the best one survives
 as the corresponding one in POP for next generation;
 The population Tempbest replace the second half of POP as the parent ones for next generation;
 Update , by (10), (13) respectively;
End for