Parameter Identification of Anaerobic Wastewater Treatment Bioprocesses Using Particle Swarm Optimization

Table 3

Influence of the noise level.

Estimated parameter	“Real” value	Noise level
		50 dB	40 dB	30 dB
𝜃1	5.5	5.4001	5.3697	5.3362
𝜃2	1	1.0066	0.6628	0.4180
𝜃3	16	15.5721	16.6508	16.3867
𝜃4	10	9.8502	9.8463	9.7771
𝜃5	1.5	1.1817	1.1428	0.9150
𝜃6	0.2	0.1867	0.2769	0.2711
𝜃7	3	2.9626	2.9178	3.1112
𝜃8	0.2	0.2042	0.2350	0.3020
𝜃9	0.6	0.6030	0.6254	0.5744
𝜃10	0.75	0.3306	0.2379	0.0058
𝜃11	4	3.7860	4.7660	4.5629
𝜃12	20	20.8802	20.9267	19.7113
NMSE	0	3.6827e − 3	0.0827	0.1625