简介:Lowgainfeedbackreferstocertainfamiliesofstabilizingstatefeedbackgainsthatareparameterizedinascalarandgotozeroasthescalardecreasestozero.Lowgainfeedbackwasinitiallyproposedtoachievesemi-globalstabilizationoflinearsystemssubjecttoinputsaturation.Itwasthencombinedwithhighgainfeedbackindifferentwaysforsolvingvariouscontrolproblems.Theresultingfeedbacklawsarereferredtoaslow-and-highgainfeedback.Sincetheintroductionoflowgainfeedbackinthecontextofsemi-globalstabilizationoflinearsystemssubjecttoinputsaturation,therehasbeenefforttodevelopalternativemethodsforlowgaindesign,tocharacterizekeyfeaturesoflowgainfeedback,andtoexplorenewapplicationsofthelowgainandlow-and-highgainfeedback.Thispaperreviewsthedevelopmentsinlowgainandlow-and-highgainfeedbackdesigns.
简介:Anovellowpowerandlowvoltagecurrentmirrorwithaverylowcurrentcopyerrorispresentedandtheprincipleofitsoperationisdiscussed.Inthiscircuit,thegainboostingregulatedcascodeschemeisusedtoimprovetheoutputresistance,whileusinginverterasanamplifier.ThesimulationresultswithHSPICEinTSMC0.18umCMOStechnologyaregiven,whichverifythehighperformanceoftheproposedstructure.Simulationresultsshowaninputresistanceof0.014Ωandanoutputresistanceof3GΩ.Thecurrentcopyerrorisfavorableaslowas0.002%togetherwithaninput(theminimuminputvoltageofvin,min~0.24V)andanoutput(theminimumoutputvoltageofvout,min~0.16V)complianceswhileworkingwiththe1Vpowersupplyandthe50uAinputcurrent.Thecurrentcopyerrorisnearzeroattheinputcurrentof27uA.Itconsumesonly76uWandintroducesaverylowoutputoffsetcurrentof50pA.
简介:Themanagementofpatientswithseveresymptomaticaorticstenosisandahightransvalvulargradientisstraightforward.Itrequiresaorticvalvereplacement.Managementofaorticstenosispatientswithlowflow,lowejectionfractionandlowgradientisfraught.Suchpatientsrarelyfulfillallthetenetsof“severity”andalsohavesevereleftventriculardysfunction.Bothcircumstancesmaketheoutcomeofaorticvalvereplacementuncertain.Thusthemanagementofthisgroupofpatientsrequiresintegrationofalldiagnosticmodalitiesavailable.Thephysicalexamination,degreeofvalvecalcification,theappearanceofthevalveduringsonographicexaminationandthepresenceofinotropicreserveallcontributeimportantlyinjudgingstenosisseverityandthelikelihoodofsuccessfulvalvereplacement.
简介:Themagneticimprovisedexplosivedevices(IEDs),alsocommonlyknownasatypeofastickybomb,issimplyconstructeddevicesyetverylethal.Thispaperputsforwardtheideaofanelectroniccompassthatiscapableofsensingthechangeofamagneticfieldgeneratedbyamagnetandtranslatingitintointerpretabledata,whichcouldactasthebaseforthefurtherstudiesandassistindevelopingagreenerautomatedsystemfordetectingthisdevice.Theelectroniccompassisspecificallychosenforreducingpowerconsumptionofsystemsinadditiontothefactthatitisavailableatalowcost.