= [ Ibb(Tg,L) - Ibb(Th,L) ] * (1 - exp[-ecsv *g]) * (1 - exp[-ecsv *h]) * exp[-ecsv *s] * cos(q) * dw
= [ Ibb(Tg,L) - Ibb(Th,L) ] * (1 - exp[-ecsv *g]) * (1 - exp[-ecsv *h]) * exp[-ecsv *s] * cos(q) * dw