Rapid and Simultaneous Prediction of Eight Diesel Quality Parameters through ATR-FTIR Analysis

Table 6

PLS models using different variable selection approaches.

Variable selection	Number of variables	Number of LVs	RMSEP	r (val)	Number of variables	Number of LVs	RMSEP	r (val)
	Density				Flash point
None	1738	9	0.50	0.996	1738	8	2.30	0.876
Manual	1124	10	0.55	0.995	1124	7	2.20	0.888
FiPLS	225	8	0.46	0.997	300	6	2.23	0.885
BiPLS	1363	8	0.49	0.996	1663	8	2.19	0.889
GA	439	9	0.43	0.997	380	7	2.17	0.889
	Sulfur content				T10
None	1738	6	0.013	0.981	1738	9	4.19	0.922
Manual	1124	6	0.014	0.976	1124	10	4.16	0.923
FiPLS	175	5	0.011	0.987	350	8	4.24	0.920
BiPLS	1363	7	0.011	0.985	1563	10	4.13	0.925
GA	434	7	0.011	0.986	370	9	4.24	0.921
	T50				T85
None	1738	6	3.20	0.951	1738	8	4.70	0.799
Manual	1124	5	3.24	0.951	1124	8	4.78	0.793
FiPLS	75	8	3.26	0.949	75	6	4.90	0.775
BiPLS	1638	6	3.10	0.954	1088	10	4.75	0.797
GA	410	5	2.97	0.957	395	6	4.81	0.788
	Cetane index				Biodiesel content
None	1738	9	0.64	0.910	1738	5	0.21	0.930
Manual	1124	8	0.63	0.912	1124	9	0.20	0.936
FiPLS	225	7	0.62	0.914	150	8	0.21	0.932
BiPLS	1363	7	0.61	0.917	873	8	0.20	0.935
GA	405	6	0.62	0.914	452	6	0.20	0.937