▁few ▁attempts , ▁no ▁conclus ive ▁solution ▁has ▁yet ▁been ▁found . ▁Ben ▁Log an ▁from ▁Bell ▁L abs ▁wrote ▁an ▁article ▁in ▁ 1 9 7 7 ▁in ▁the ▁Bell ▁System ▁Techn ical ▁Journal ▁giving ▁some ▁criteria ▁under ▁which ▁unique ▁reconst ruction ▁is ▁possible . ▁Though ▁this ▁has ▁been ▁a ▁major ▁step ▁towards ▁the ▁solution , ▁many ▁people ▁are ▁diss atisf ied ▁with ▁the ▁type ▁of ▁condition ▁that ▁results ▁from ▁his ▁article . ▁ ▁According ▁to ▁Log an , ▁a ▁signal ▁is ▁uniqu ely ▁re construct ible ▁from ▁its ▁zero ▁cross ings ▁if : ▁ ▁The ▁signal ▁x ( t ) ▁and ▁its ▁Hil bert ▁transform ▁ xt ▁have ▁no ▁zeros ▁in ▁common ▁with ▁each ▁other . ▁ ▁The ▁frequency - domain ▁representation ▁of ▁the ▁signal ▁is ▁at ▁most ▁ 1 ▁oct ave ▁long , ▁in ▁other ▁words , ▁it ▁is ▁band pass - limited ▁between ▁some ▁frequencies ▁B ▁and ▁ 2 B . ▁ ▁Further ▁reading ▁▁ ▁B . ▁F . ▁Log an , ▁Jr . ▁" Information ▁in ▁the ▁Zero ▁Cross ings ▁of ▁Band pass ▁Sign als ", ▁Bell ▁System ▁Techn ical ▁Journal , ▁vol . ▁ 5 6 , ▁pp .   4 8 7 – 5 1 0 , ▁April ▁ 1 9 7 7 . ▁ ▁External ▁links ▁▁ ▁Re const ruction ▁of ▁two - dimensional ▁signals ▁from ▁threshold ▁cross ings ▁ ▁Category : Sign al ▁processing <0x0A> </s> ▁The ▁ 2 0 1 1 ▁T IM ▁Super co ppa ▁Italiana ▁Final ▁was ▁the ▁ 2 4