Transportation Risk Control of Waste Disposal in the Healthcare System with Two-Echelon Waste Collection Network

Table 3

Comparison between CPLEX solver and PSO algorithm on small-scale instances.

Instance		CPLEX		PSO
Group	ID					(%)
ISG1	1	1805.67	14.3	1874.69	10.7	3.82
	2	1652.55	41.7	1663.95	10.4	0.69
	3	1672.35	3.4	1729.20	10.5	3.40
	4	1722.14	15.5	1788.40	11.9	3.85
ISG2	1	2282.41	93.0	2446.26	20.7	7.18
	2	2137.46	1232.6	2265.62	33.4	6.00
	3	2265.72	1765.3	2360.77	35.1	4.20
	4	2174.38	178.2	2305.10	33.2	6.01
ISG3	1	—	>7200	4059.08	61.2	—
	2	—	>7200	3423.35	61.1	—
	3	—	>7200	3691.92	61.8	—
	4	—	>7200	3502.65	59.2	—
Average					34.1	4.39

Notes: (1) represents the optimal solution obtained by CPLEX. denotes the global best solution obtained by the PSO algorithm. (2) and are the computation times of CPLEX and PSO algorithm in seconds, respectively. (3) .