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1、2019高考英语二轮阅读理解专练(详解)—科普知识Trafficlightsarekeytoolsforregulatingtrafficnow.Theyarenot,however,perfect.Driversexchangethetrafficjamsthatwouldhappenatunmanagedcrossingsforapatternofstopgomovementthatcanstillbeannoying,andwhichburnsmorefuelthanasmoothpassagewould.Creatingsuchasmoothpassag
2、emeansadjustingavehicle'sspeedsothatitalwaysarrivesatthelightswhentheyaregreen.Thatistheoreticallypossible,butpracticallyhard.Roadsidesignswiredtotrafficlightscanhelpgetthemessageacrossacouplehundredmetresfromacrossing,butsuchsignsareexpensive,andarenotwidespread.MargaretMartonosiandE
3、mmanouilKoukoumidisatPrincetonUniversity,andLiShiuanPehattheMassachusettsInstituteofTechnology,however,haveanideathatcouldmaketheprocesscheaperandmoreeffective.Insteadofahardwirednetworkofsigns,theyproposetousemobilephoneapplications.Foradrivertobenefit,hemustloadtheteam'ssoftware,n
4、amedSignalGuru,intohisphoneandthenputitonaspecialthingattachedtotheinsideofhiscar'swindscreen,withthecameralens(镜头)pointingforward.SignalGuruisdesignedtodetecttrafficlightsandtracktheirstatusasred,yelloworgreen.Itbroadcaststhisinformationtootherphonesintheareathatarefittedwiththesames
5、oftware,and—ifthereareenoughofthem,thephonesthuseachknowthestatusofmostofthelightsaroundtown.Usingthisinformation,SignalGuruisabletocalculatethetrafficlightschedulefortheareaandsuggestthespeedatwhichadrivershouldtravelinordertoavoidredlights.TestsinCambridge,Massachusetts,wherefivedr
6、iverswereaskedtofollowthesamerouteforthreehours,andinSingapore,whereeightdriverswereaskedtofollowoneoftworoutesfor30minutes,revealedthatSignalGuruwascapableofpredictingtrafficlightactivitywithanaccuracyof98.2%and96.3%respectively,inthetwocities.ThiswasparticularlyimpressivebecauseinC
7、ambridgethelightsshifted,roughlyhalfwaythroughthetest,fromtheirunbusyscheduletotheirafternoontrafficschedule,whileinSingaporelightsareadaptive,usingdetectorsfixedundertheroadtodeterminehowmuchtrafficispresentandthuswhenasignalshouldchange.InneithercasewasSignalGurufooled.Fuelconsump
8、tionf