, ▁ 1 9 9 8 . ▁Cooper , ▁J ef fer y , ▁" Param et ric ▁Res on ance ▁in ▁W ave ▁Equ ations ▁with ▁a ▁Time - Period ic ▁Pot ential ". ▁SI AM ▁Journal ▁on ▁Mathemat ical ▁Analysis , ▁Volume ▁ 3 1 , ▁Number ▁ 4 , ▁pp .   8 2 1 – 8 3 5 . ▁Society ▁for ▁Indust rial ▁and ▁App lied ▁Mathemat ics , ▁ 2 0 0 0 . ▁" D ri ven ▁P end ul um : ▁Param et ric ▁Res on ance ". ▁phys . c mu . edu ▁( D emon str ation ▁of ▁physical ▁mechan ics ▁or ▁classical ▁mechan ics . ▁Res on ance ▁oscill ations ▁set ▁up ▁in ▁a ▁simple ▁p end ul um ▁via ▁period ically ▁varying ▁p end ul um ▁length .) ▁M um ford , ▁W . ▁W ., ▁" Some ▁notes ▁on ▁the ▁history ▁of ▁paramet ric ▁trans du cers ". ▁Pro ceed ings ▁of ▁the ▁I RE , ▁Volume ▁ 9 8 , ▁Number ▁ 5 , ▁pp .   8 4 8 – 8 5 3 . ▁Institute ▁of ▁Elect rical ▁and ▁Electron ics ▁Engine ers , ▁May ▁ 1 9 6 0 . ▁ ▁Category : Am pl ifiers ▁Category : D ynam ical ▁systems ▁Category : E lect ron ic ▁oscill ators ▁Category : Ord inary ▁differential ▁equations <0x0A> </s> ▁Emil ▁Be eler ▁( born ▁ 7 ▁November ▁ 1 9 3 7 ) ▁is ▁a ▁former ▁Swiss ▁cycl ist