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

Table 7

Effects of various standard deviations on the average MSEs of HS, IHS, NGHS, and IGHS.

Problem	NI	Algorithm
Example a ()	2000	HS	0.031915	0.026339	0.021641	0.020161	0.031606	0.030344	0.073344
		IHS	0.023133	0.01932	0.018847	0.017164	0.025531	0.02863	0.06602
		NGHS	0.012373	0.01317	0.0080251	0.0087471	0.017701	0.015685	0.05541
		IGHS	0.0090595	0.0081459	0.0063491	0.0060281	0.0082031	0.012456	0.05064
Example a ()	5000	HS	0.04305	0.053554	0.044272	0.061806	0.052752	0.056594	0.072702
		IHS	0.040038	0.05833	0.039185	0.050786	0.059166	0.044153	0.065037
		NGHS	0.01394	0.017639	0.011319	0.016349	0.017154	0.022171	0.034087
		IGHS	0.0042096	0.0054617	0.0032124	0.004798	0.0065079	0.01026	0.021561
Example b ()	2000	HS	0.0020816	0.002023	0.0021274	0.0023366	0.0048039	0.011212	0.044087
		IHS	0.0016932	0.0016984	0.001846	0.0020514	0.0042728	0.010803	0.043885
		NGHS	0.0016883	0.0016907	0.0018335	0.0019744	0.004277	0.010804	0.043811
		IGHS	0.0016881	0.0016894	0.0018321	0.0019734	0.0042728	0.010799	0.043809
Example b ()	5000	HS	0.0021598	0.002027	0.0018595	0.0023973	0.0035314	0.011308	0.042578
		IHS	0.0017257	0.0017276	0.0017401	0.0022161	0.0034728	0.011198	0.042543
		NGHS	0.0017311	0.0017232	0.0017334	0.0022162	0.0034424	0.011172	0.0425
		IGHS	0.0017063	0.0017185	0.0017295	0.0022099	0.0034249	0.011163	0.042491
Example a ()	5000	HS	2.8627	3.9382	3.7033	3.2856	3.5386	5.1986	3.1728
		IHS	2.8343	3.9123	3.6921	3.2648	3.5163	5.1678	3.1443
		NGHS	2.6651	3.7442	3.5112	3.0952	3.3575	4.9886	2.9954
		IGHS	2.6546	3.7404	3.4886	3.0747	3.3407	4.9715	2.9847
Example b ()	5000	HS	1.2711	1.2759	1.2776	1.2868	1.292	1.2358	1.3175
		IHS	1.2339	1.236	1.2508	1.2473	1.242	1.2165	1.2836
		NGHS	1.0437	1.0418	1.0432	1.0411	1.0456	1.0064	1.0917
		IGHS	1.0276	1.0264	1.0294	1.029	1.0219	0.99213	1.0689