An Improved Global Harmony Search Algorithm for the Identification of Nonlinear Discrete-Time Systems Based on Volterra Filter Modeling

Table 4

Comparison of HS, IHS, NGHS, and IGHS on six problems.

Problem	NI	Algorithm	ACT	Best	Worst	Mean	Std
Example a ()	2000	HS	1.659
		IHS	1.7011
		NGHS	1.781
		IGHS	2.6365
Example a ()	5000	HS	4.3975
		IHS	4.4121
		NGHS	4.4334
		IGHS	6.6589
Example b ()	2000	HS	0.57743
		IHS	0.56219
		NGHS	0.56886
		IGHS	0.84918
Example b ()	5000	HS	2.6544
		IHS	2.651
		NGHS	2.6787
		IGHS	4.0572
Example a ()	5000	HS	5.3252
		IHS	5.2646
		NGHS	5.3327
		IGHS	7.9408
Example b ()	5000	HS	3.1802
		IHS	3.1454
		NGHS	3.1735
		IGHS	4.7435