. 2015 Dec 19;15(12):31999–32019. doi: 10.3390/s151229907

Table 9.

Features’ importance computed during age classification using the 10-fold cross-validation strategy. The top 5 contributing features are highlighted with bold text. All values are the percentage.

		Len	Dur	Mean	SD	Min	Max	RMS	Ent	E	Amp
Chest	A $_{x}$	1.50	1.46	2.26	2.29	3.25	2.37	2.89	2.00	1.75	2.21
	A $_{y}$	–	–	2.74	1.83	1.97	2.16	1.73	1.67	1.83	2.11
	A $_{z}$	–	–	3.63	2.31	2.98	3.17	3.40	2.19	3.11	1.54
	G $_{x}$	–	–	1.49	1.44	1.31	1.43	2.24	1.47	2.38	1.76
	G $_{y}$	–	–	0.99	2.00	2.09	2.05	1.95	0.90	1.90	1.30
	G $_{z}$	–	–	1.28	2.14	1.56	1.49	1.92	1.10	2.02	1.42
Lower Back	A $_{x}$	1.22	1.28	1.51	1.99	1.49	1.63	1.91	1.69	1.42	2.26
	A $_{y}$	–	–	2.99	1.29	1.73	1.85	1.65	1.74	1.61	1.22
	A $_{z}$	–	–	4.75	2.22	4.15	3.28	2.80	2.38	2.76	1.56
	G $_{x}$	–	–	1.64	2.86	1.72	1.63	1.58	1.25	1.62	1.67
	G $_{y}$	–	–	1.35	2.16	2.06	2.09	2.17	1.44	1.98	1.95
	G $_{z}$	–	–	1.90	1.94	1.59	1.74	2.38	1.81	1.94	3.17
Right Wrist	A $_{x}$	1.68	1.65	1.66	2.10	1.62	1.66	1.93	2.05	2.65	1.98
	A $_{y}$	–	–	2.71	1.85	2.60	2.65	2.15	1.73	2.00	1.52
	A $_{z}$	–	–	2.35	1.96	2.42	3.42	2.35	1.97	2.17	1.52
	G $_{x}$	–	–	1.81	1.56	1.67	1.34	1.75	1.44	1.68	1.35
	G $_{y}$	–	–	1.78	2.14	1.63	2.18	1.97	1.74	2.07	1.67
	G $_{z}$	–	–	2.03	2.57	2.79	2.23	2.25	1.81	2.26	1.95
Left Ankle	A $_{x}$	1.10	1.15	1.29	1.66	2.16	1.79	1.70	1.35	1.59	1.58
	A $_{y}$	–	–	2.58	1.63	2.54	1.84	2.06	1.70	1.94	1.54
	A $_{z}$	–	–	2.75	1.68	3.42	2.84	1.58	2.27	1.83	1.80
	G $_{x}$	–	–	2.20	1.96	2.47	1.62	1.93	1.56	1.81	1.78
	G $_{y}$	–	–	2.21	1.96	2.14	4.72	1.79	1.81	2.06	1.84
	G $_{z}$	–	–	2.52	1.94	2.56	2.09	1.93	1.74	2.06	1.90