Nondestructive Testing on Ancient Wooden Components Based on Shapley Value

Table 3

Comparison of nondestructive testing methods.

Number	Type	Proportion	Actual defect S0 (cm^2)	Stress wave S1 (cm^2)	Drilling resistance S2 (cm^2)	Combined prediction S3 (cm^2)	Absolute error value		Relative error value
							Stress wave R1 (cm^2)	Drilling resistance R2 (cm^2)	Stress wave Q1 (%)	Impedance meter Q2 (%)	Combined prediction Q3 (%)
D-1	Core material cavity	0	0	0	0	0	0	0	0	0	0
		1/9	63.96	86.35	52.85	65.92	22.39	11.11	35.01	17.37	3.06
		1/7	82.24	138.16	68.11	95.43	55.92	14.13	68.00	17.18	16.04
		1/5	115.13	149.67	95.41	116.57	34.54	19.72	30.00	17.13	1.25
		1/3	191.89	178.45	158.88	178.21	16.56	33.01	8.63	17.20	7.13
		1/2	287.83	316.61	237.94	268.62	28.78	49.89	10.00	17.33	6.67
Average			123.51	144.87	102.20	120.79	26.37	21.31	25.27	14.37	5.69
D-2	Sapwood cavity	0	0	0	0	0	0	0	0	0	0
		1/9	63.96	72.08	50.73	60.34	8.12	13.23	12.70	20.69	5.66
		1/7	82.24	104.35	71.42	86.24	22.11	10.82	26.89	13.16	4.86
		1/5	115.13	155.43	92.26	120.69	40.30	22.87	35.00	19.87	4.83
		1/3	191.89	236.02	163.39	196.07	44.13	28.50	23.00	14.85	2.18
		1/2	287.83	324.29	226.54	270.53	36.46	61.29	12.67	21.29	6.01
Average			123.51	148.70	100.72	122.31	30.22	27.34	18.38	14.98	3.92