Pe ople ▁from ▁Pad ua ▁Category : Ital ian ▁botan ists ▁Category : Ital ian ▁arch ae olog ists ▁Category : 1 8 th - century ▁Italian ▁people ▁Category : M embers ▁of ▁the ▁Royal ▁Swedish ▁Academy ▁of ▁Sciences ▁Category : F ell ows ▁of ▁the ▁Royal ▁Society ▁Category : M use o ▁Eg izio <0x0A> </s> ▁A ▁paramet ric ▁oscill ator ▁is ▁a ▁driven ▁harm onic ▁oscill ator ▁in ▁which ▁the ▁oscill ations ▁are ▁driven ▁by ▁varying ▁some ▁parameter ▁of ▁the ▁system ▁at ▁some ▁frequency , ▁typically ▁different ▁from ▁the ▁natural ▁frequency ▁of ▁the ▁oscill ator . ▁A ▁simple ▁example ▁of ▁a ▁paramet ric ▁oscill ator ▁is ▁a ▁child ▁p ump ing ▁a ▁play ground ▁swing ▁by ▁period ically ▁standing ▁and ▁squ atting ▁to ▁increase ▁the ▁size ▁of ▁the ▁swing ' s ▁oscill ations . ▁The ▁child ' s ▁mot ions ▁vary ▁the ▁moment ▁of ▁in ert ia ▁of ▁the ▁swing ▁as ▁a ▁p end ul um . ▁The ▁" p ump " ▁mot ions ▁of ▁the ▁child ▁must ▁be ▁at ▁twice ▁the ▁frequency ▁of ▁the ▁swing ' s ▁oscill ations . ▁Ex amples ▁of ▁parameters ▁that ▁may ▁be ▁varied ▁are ▁the ▁oscill ator ' s ▁reson ance ▁frequency ▁ ▁and ▁d amp ing ▁. ▁ ▁Param et ric ▁oscill ators ▁are ▁used ▁in ▁several ▁areas ▁of ▁physics . ▁The ▁classical ▁var actor ▁paramet ric ▁oscill ator ▁consists ▁of ▁a ▁sem icon duct or ▁var actor ▁di ode ▁connected ▁to ▁a ▁reson ant ▁circuit ▁or ▁cav ity ▁reson ator . ▁It ▁is