On the Investigation of Effective Factors on Higher Heating Value of Biodiesel: Robust Modeling and Data Assessments

Table 1

A comparison of the models in MRE, RMSE, MSE, STD, and -squared for the training, testing, and total data under various Kernel functions.

Model	Phase		MRE (%)	MSE	RMSE	STD
GPR (exponential)	Train	0.973	2.70	0.45	0.67	0.46
	Test	0.907	4.53	1.03	1.02	0.63
	Total	0.961	3.11	0.58	1.02	0.52
GPR (Matern)	Train	0.951	3.57	0.78	0.88	0.59
	Test	0.932	4.07	0.80	0.90	0.52
	Total	0.944	3.82	0.83	0.90	0.59
GPR (squared exponential)	Train	0.941	3.40	0.72	0.85	0.58
	Test	0.947	4.91	1.18	1.09	0.69
	Total	0.940	3.99	0.89	1.09	0.62
GPR (rational quadratic)	Train	0.946	3.94	0.92	0.96	0.64
	Test	0.928	3.65	0.59	0.77	0.40
	Total	0.943	3.86	0.84	0.77	0.59