Algorithm 2. Modified PSO Algorithm.

1

2

3

4

5

6

7

8

9

10

11

12

13

14

15

16

17

18

19

20

for each cluster do

for i = 1 to P do

p_i ←initialize_particle()

l_i ← p_i

if i = 1 or fitness(l_i) > fitness(g) then

g ← l_i

for it = 1 to M do

for i = 1 to P do

r_p, r_g ~ uniform(0.0, 1.0)

p_i ← mutation(p_i, ω)

if r_p < φ_p then

p_i ← crossover(p_i, l_i)

if r_g < φ_g then

p_i ← crossover(p_i, g)

if fitness(p_i) > fitness(l_i) then

l_i ← p_i

if fitness(p_i) > fitness(g) then

g ← p_i