Aij	the code of city which is the j-th nearest city to the i-th city
A[i]	the code of C cities which are nearest to the i-th city
C	the column number of greedy black box matrix
c1, c2	acceleration coefficients
Dk	optimal route length at k-th Monte-Carlo simulation
Di	optimal route length of i-th particle
Mcri	critical iteration number
m	current number of iterations
N	numbers of particles
PC	crossover probability
Pgs	global optimum position
PM	mutation probability
Pis	individual optimum position
Q	the number of planned points
R	population size
r1, r2	random number
s	the s-th dimension
Vi	velocity vector
vis	individual velocity vector
w	inertia weight
Xi	position vector
xis	individual position vector
α	information heuristic factor
β	expectation heuristic factor
ρ	pheromone evaporation ratio