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

Table 6

The compared results for small-sized problem.

Problem size	Tugboats				Algorithm			Mean time
(ship × tugboat)	2600	3200	3400	4000		(min.)	(min.)	(s)
5 × 4	1	1	1	1	IDPSO	135	135	2
					BDPSO	175	183	3
					GA	135	159	2
5 × 7	1	2	2	2	IDPSO	80	80	5
					BDPSO	120	136.75	7
					GA	80	110.75	2
6 × 4	1	1	1	1	IDPSO	175	175	2
					BDPSO	183	213.2	4
					GA	175	181	3
6 × 7	1	2	2	2	IDPSO	108	110.8	7
					BDPSO	123	161.3	9
					GA	108	131.3	3
7 × 6	2	2	1	1	IDPSO	168	182.8	7
					BDPSO	195	238.7	9
					GA	168	194.15	3
7 × 6	1	1	2	2	IDPSO	160	172.35	7
					BDPSO	185	229.95	9
					GA	160	183.65	3
7 × 8	2	2	2	2	IDPSO	125	140.75	10
					BDPSO	200	227.35	14
					GA	135	174.9	3
8 × 6	2	2	1	1	IDPSO	173	197.4	8
					BDPSO	193	251.5	8
					GA	193	217.8	4
8 × 6	1	1	2	2	IDPSO	160	185.6	8
					BDPSO	193	236.85	8
					GA	185	208.3	4
8 × 8	2	2	2	2	IDPSO	135	156.3	12
					BDPSO	248	282.5	25
					GA	160	197.45	4
10 × 10	3	3	2	2	IDPSO	208	237.85	26
					BDPSO	308	363.9	45
					GA	216	279.25	6
10 × 10	2	2	3	3	IDPSO	185	218.65	25
					BDPSO	305	362.2	46
					GA	245	290.7	6