Hybridizing Grid Search and Support Vector Regression to Predict the Compressive Strength of Fly Ash Concrete

Table 1

Statistical characteristics of variables.

		Cement	Fly ash	Water	Super plasticizer	Coarse aggregate	Fine aggregate	Age	Compressive strength
Training set	Unit	kg/m^3	kg/m^3	kg/m^3	kg/m^3	kg/m^3	kg/m^3	d	MPa
	Count	78	78	78	78	78	78	78	78
	Maximum	376	163.3	216.7	18	1118	905.4	90	72.11
	Minimum	136.1	92.1	141.1	0	801	700	3	9.49
	Standard deviation	54.22	9.68	18.12	4.65	67.60	44.70	29.72	13.37
	Mean	243.95	123.54	177.77	6.46	1010.62	800.34	34.06	31.85
	Skewness	0.25	−0.05	−0.18	−0.07	−0.97	0.63	0.97	0.63
	Kurtosis	−0.75	9.44	−0.81	−0.88	0.79	0.23	−0.40	0.02
Test set	Count	20	20	20	20	20	20	20	20
	Maximum	349	168.3	220.5	16.1	1111.6	856.5	90	41.64
	Minimum	144	95.7	158.2	0	801.1	687	3	9.55
	Standard deviation	59.46	11.81	17.50	5.79	75.95	43.85	25.71	9.53
	Mean	231.28	125.19	182.27	5.77	969.55	771.99	32.70	25.49
	Skewness	0.46	1.78	0.51	0.34	−0.29	−0.17	1.52	0.21
	Kurtosis	−0.80	10.57	−0.11	−1.47	−0.05	−0.73	1.65	−1.20