An Improved Discrete PSO for Tugboat Assignment Problem under a Hybrid Scheduling Rule in Container Terminal

Table 7

The compared results for middle-sized problem.

Problem size	Tugboats				Algorithm			Mean time
(ship × tugboat)	2600	3200	3400	4000		(min.)	(min.)	(s)
15 × 10	3	3	2	2	IDPSO	375	412.4	47
					BDPSO	528	621.55	65
					GA	446	509.4	22
15 × 10	2	2	3	3	IDPSO	330	398.35	47
					BDPSO	509	596.7	60
					GA	428	495.45	22
15 × 12	3	3	3	3	IDPSO	343	409.1	70
					BDPSO	523	601	89
					GA	393	515.85	28
20 × 10	2	2	3	3	IDPSO	498	547.2	79
					BDPSO	701	795.25	120
					GA	596	695.4	41
20 × 12	3	3	3	3	IDPSO	475	567.2	119
					BDPSO	613	757.2	234
					GA	588	767.65	54
30 × 12	3	3	3	3	IDPSO	959	1070.7	321
					BDPSO	1257	1427.5	828
					GA	1265	1433.4	115
30 × 15	3	4	4	4	IDPSO	858	970	486
					BDPSO	1144	1303.1	1095
					GA	1026	1243.2	151
50 × 12	3	3	3	3	IDPSO	1832	1957.85	1110
					BDPSO	2276	2424	2670
					GA	2167	2491.35	326
50 × 15	3	4	4	4	IDPSO	1683	1814.8	1678
					BDPSO	2119	2245.65	5408
					GA	2089	2252	419
80 × 15	3	4	4	4	IDPSO	3179	3387.6	5870
					BDPSO	3862	4045.0	13247
					GA	3834	4064.15	973