(a)Architecture of the improved transformer [53]. (b) Training and validation loss curves of transformer and MLP for spectrum-based prediction. Prediction accuracy of transformer and MLP [53]. (c) Prediction accuracy of VIT and CNN. Training and validation loss curves of VIT versus CNN for 2-D heat map prediction [53]. (d) Reflectance spectra of target and predicted thicknesses based on MLP and improved transformer algorithms [53]. (e) Architecture of the improved VIT [53].