Comparative Study of Swarm-Based Algorithms for Location-Allocation Optimization of Express Depots

Table 1

Symbols and description.

Description	Symbol	Property
Maximum number of distribution centers		Parameter
Number of distribution centers		Decision variable
Number of delivery points		Parameter
Horizontal coordinate of distribution center		Decision variable
Vertical coordinate of distribution center		Decision variable
Maximum horizontal coordinate of distribution center
Horizontal coordinate of the delivery point		Parameter
Vertical coordinate of the delivery point		Parameter
Distance between the -th distribution center and -th delivery point		Parameter
Capacity of distribution center		Decision variable
The demand of delivery point		Parameter
Total demand of all delivery points		Parameter
Set of all delivery points		Parameter
Set of delivery points served by distribution center		Decision variable
Average operational cost is determined by the position of the distribution center		Parameter