▁calculated ▁by ▁adding ▁the ▁C α − 1 - C α 0 ▁and ▁C α + 1 - C α 0 ▁vectors . ▁ ▁H SE ▁is ▁used ▁in ▁predict ing ▁dis continu ous ▁B - cell ▁ep it op es . ▁ ▁Song ▁et ▁al . ▁have ▁developed ▁an ▁online ▁web server ▁term ed ▁H SE pred ▁to ▁predict ▁half - s phere ▁expos ure ▁from ▁protein ▁primary ▁sequences . ▁H SE pred ▁server ▁can ▁achieve ▁the ▁correlation ▁coefficients ▁of ▁ 0 . 7 2 ▁and ▁ 0 . 6 8 ▁between ▁the ▁predicted ▁and ▁observed ▁H SE - up ▁and ▁H SE - down ▁measures , ▁respectively , ▁when ▁evaluated ▁on ▁a ▁well - prep ared ▁non - hom olog ous ▁protein ▁structure ▁dataset . ▁Moreover , ▁resid ue ▁contact ▁number ▁( CN ) ▁can ▁also ▁be ▁accur ately ▁predicted ▁by ▁H SE pred ▁web server ▁using ▁the ▁summ ation ▁of ▁the ▁predicted ▁H SE - up ▁and ▁H SE - down ▁values , ▁which ▁has ▁further ▁en larg ed ▁the ▁application ▁of ▁this ▁new ▁sol vent ▁expos ure ▁measure . ▁ ▁Rec ently , ▁He f fer nan ▁et ▁al . ▁has ▁developed ▁the ▁most ▁accurate ▁predict or ▁for ▁both ▁H SE α ▁and ▁H SE β ▁based ▁on ▁a ▁big ▁dataset ▁by ▁using ▁multiple - step ▁iter ative ▁deep ▁neural - network ▁learning . ▁The ▁predicted ▁H SE a ▁shows ▁a ▁higher ▁correlation ▁coefficient ▁to ▁the ▁stability ▁change ▁by ▁resid ue ▁mut ants ▁than ▁predicted ▁H SE β ▁and