Parallel computation of XGBoost: Although the Phone Number List base CART trees in XGBoost are serial to each other, the generation of individual base CART trees can be taken in parallel computation. 5) Overfitting treatment of XGBoost: In addition to Phone Number List adding regularization terms to the objective function to alleviate overfitting, other methods such as limiting the maximum depth of the tree, shrinkage, and feature subsampling can also Phone Number List be used. After the model is established, the accuracy rate of each subcategory and the overall accuracy rate of the model discrimination are used as its evaluation index.
The higher the accuracy rate is, the stronger the Phone Number List discriminative performance of model is. Results and discussion Extraction and analysis of features Extraction and analysis of spectral features Figure 2 shows the average spectra of healthy Phone Number List samples and samples with different bruising times and the corresponding images of bruised yellow peaches at four different times. The yellow peach’s bruise region spectra were extracted by ENVI4.5 software and the region of interest (ROI) size was 160 pixels. From Fig. 2, it can be seen that the reflectance of the sound samples is highest, while the spectral reflectance of the four types of bruised Phone Number List samples is different, their general trends are similar.
The longer the storage time of bruise’s yellow Phone Number List peaches are, the lower the reflectance of their average spectra is. This may be due to the different browning degrees of the bruised area; this makes its different absorption in light. As the browning Phone Number List degree of the bruised area of samples increasing with the storage time, the browning degree changes more obvious at the beginning, the browning degree is close to the maximum value Phone Number List at 24 h, so that the browning degree doesn’t change much at 48 h comparing with 24 h.