Isomap-Based Three-Dimensional Operational Modal Analysis

Table 19

PCA and Isomap by DMA with a real modal damping ratio of 0.1.

Real order	Identified order	DMA
		PCA (MDS)			Isomap
		MAC	Frequencies	Relative error (%)	MAC	Frequencies	Relative error (%)
1	2	0.5232	1081	1.716	0.5193	1081	2.474
2	1	0.4812	1044	−0.498	0.4804	1138	−0.672
3	3	0.2107	1185	−4.405	0.2033	1176	−5.131
4	4	0.1703	1406	−2.490	0.1788	1392	−3.461
5	6	0.7279	1747	0.402	0.0003	—	—
7	5	0.4739	1854	−0.946	0.5082	1889	0.924