The left table includes coefficients and right side table includes properties that used to calculate linear combination, a paper says that ''We used linear combination of specific physicochemical properties.'' and we have an equation;

Can you explain the principle and steps of this calculation?

\begin{tabular}{l|cl} Coefficient & Value & Coefficient (text) \\ \hlineai & 0,598 & a_H \\ \hlineai & 0,318 & a_c \\ \hlineai: & 5,77 & a_alpha \\ \hlineai? & 4,807 & a_beta \\ \hlinea1;it & 2,816 & a_pat \\ ayik & 0,152 & a_gk \end{tabular} \begin{tabular}{|c|c|c|c|c|} \hline Residue & Charge & Hydrophobicity* & Alpha & Beta \\ \hline A & 0 & 0,39 & 0,79 & 0,7 \\ \hline C & 0 & 2,25 & 0,49 & 0,84 \\ \hline D & 1 & 3,81 & 0,65 & 0,68 \\ \hline E & 1 & 2,91 & 0,97 & 0,73 \\ \hline F & 0 & 2,27 & 0,77 & 0,98 \\ \hline G & 0 & 0,05 & 0,21 & 0,15 \\ \hline H & 0 & 0,64 & 0,8 & 0,8 \\ \hline I & 0 & 1,82 & 0,93 & 1 \\ \hline K & 1 & 2,77 & 0,88 & 0,73 \\ \hline L & 0 & 1,82 & 0,98 & 0,86 \\ \hline M & 0 & 0,96 & 0,82 & 0,82 \\ \hline N & 0 & 1,91 & 0,61 & 0,6 \\ \hline P & 0 & 0,99 & 0,17 & 0,09 \\ \hline Q & 0 & 1,3 & 0,78 & 0,77 \\ \hline R & 1 & 3,5 & 0,95 & 0,79 \\ \hline S & 0 & 1,24 & 0,67 & 0,67 \\ \hline T & 0 & 1 & 0,52 & 0,86 \\ \hline V & 0 & 1,3 & 0,75 & 1,05 \\ \hline W & 0 & 2,13 & 0,64 & 0,86 \\ \hline Y & 0 & 1,47 & 0,73 & 0,89 \\ \hline \end{tabular} si=aHpiH+aCpiC+aapi+api