A Node Location Method in Wireless Sensor Networks Based on a Hybrid Optimization Algorithm

Pseudocode 1

The pseudocode of the proposed WOA-QT.

Generate initial population X containing N individuals .

Initialize the parameters related to the algorithm: a, r, b, prob, t, max_iter.

Initialize two matrices in QUATRE:

 the coevolutionary matrix M (Eq. (6) or Eq. (7)).

 the donor matrix B (Eq. (8)).

Initialize the parameters related to the search space size:

 ub = ub_new = ub_max.

 lb = lb_new = lb_min.

Calculate the fitness value of each solution.

X = the best individual.

 While (t < max_iter) and (not obtain the predefined function value).

 For each solution.

 Update a, r, b, l, prob, M, B.

  If1 (prob <0.5).

  If2 ().

   Update the position of the current solution using Eq. (9).

  Else if2 ().

   Select a random solution X_rand.

   Update the position of the current solution using Eq. (2).

  End if2.

Else if1 ().

   Update the position of the current solution using Eq. (10).

  End if1.

 End for.

 Check if any solution goes beyond the search space and amend it.

 Calculate the fitness value of each solution.

 Update X if there is a better solution.

 t = t +1.

 Shrink the search space size using Eq. (11) and (12).

End while.

Return X