Page 179 - Contributed Paper Session (CPS) - Volume 4

CPS2166 Divo Dharma Silalahi et al.
assumed earlier if more wavelengths excluded in the model were impact to
produce low accuracy in the prediction result. In the fourth plot of mod-VIP-
MCUVE, the green line shows the old cut-off threshold using previous MCUVE
(threshold = 5.486), while the red line is the new proposed cut-off threshold
(threshold = 2.916). The proposed mod-VIP-MCUVE method showed better
classification using the modified threshold, since there only less number of
wavelengths removed from the model, but the performance was still satisfied
and better in interpretability.
The diffuse selected reflectance is very important to identify the relevant
wavelengths with related to the %ODM. This exhibit their fundamental
attribute to the overtone or combination bands involve the molecular
stretching and bending absorption over a wide spectral range. Based on Figure
2, it was possible to observe if the well defined absorption bands are from
visible red color (668-684nm), CH2 of oil and O-H of Water (936-961nm), C-H
absorption by stretching-bending (1232-1344nm), first overtone (1404-1444)
of C-H stretch O-H of water and C-H of oil and its combinations (1700-1776)
of C-O oil and C-H stretching by first overtone, C=O absorption by stretching-
bending (1888-2008nm), C-H second overtone of protein and oil (2296-
2360nm), and corresponding to absorption which associated with the second
overtone in C-H of oil (2364-2496nm).

Figure 2. Comparison of the selected wavelengths in the scaled input variables on the NIR
spectral data of fresh fruit mesocarp using different methods

168 | I S I W S C 2 0 1 9