简介:Wearabledevicesbecomepopularbecausetheycanhelppeopleobservehealthcondition.Thebatterylifeisthecriticalproblemforwearabledevices.Thenon-volatilememory(NVM)attractsattentioninrecentyearsbecauseofitsfastreadingandwritingspeed,highdensity,persistence,andespeciallylowidlepower.Withitslowidlepowerconsumption,NVMcanbeappliedinwearabledevicestoprolongthebatterylifetimesuchassmartbracelet.However,NVMhashigherwritepowerconsumptionthandynamicrandomaccessmemory(DRAM).Inthispaper,weassumetousehybridrandomaccessmemory(RAM)andNVMarchitectureforthesmartbraceletsystem.Thispaperpresentsadatamanagementalgorithmnamedbraceletpower-awaredatamanagement(BPADM)basedonthearchitecture.TheBPADMcanestimatethepowerconsumptionaccordingtothememoryaccess,suchassamplingrateofdata,andthendeterminethedatashouldbestoredinNVMorDRAMinordertosatisfylowpower.TheexperimentalresultsshowBPADMcanreducepowerconsumptioneffectivelyforbraceletinnormalandsleepingmodes.
简介:In2010,Hwang,etal.proposeda'DoS-resistantID-basedpasswordauthenticationschemeusingsmartcards'asanimprovementofKim-Lee-Yoo's'ID-basedpasswordauthenticationscheme'.Inthispaper,wecryptanalyzeHwang,etal.'sschemeandpointoutthattherevealedsessionkeycouldthreatthesecurityofthescheme.Wedemonstratethatextractinginformationfromsmartcardsisequaltoknowingthesessionkey.Thusknownsessionkeyattacksarealsoeffectiveundertheas-sumptionthattheadversarycouldobtaintheinformationstoredinthesmartcards.WeproposedanimprovedschemewithsecurityanalysistoremedytheweaknessesofHwang,etal.'sscheme.Thenewschemedoesnotonlykeepallthemeritsoftheoriginal,butalsoprovidesseveraladditionalphasestoimprovetheflexibility.Finally,theimprovedschemeismoresecure,efficient,practical,andconvenient,becauseellipticcurvecryptosystemisintroduced,theexpensivesmartcardsandsynchronizedclocksystemarereplacedbymobiledevicesandnonces.
简介:TheInternetofthing(IoT)emergesasapossiblesolutiontorealizeasmartlifeinthemodernage.Inthisarticle,wedesignandrealizeanovelnearfieldcommunication(NFC)-drivensmarthomesystemforIoT,whichintegratesthewirelesssensornetwork(WSN),socialnetworks,andthecloudcomputing.NFCtechnologyprovidesawayforuserstoexchangeinformationbetweenthemandthesystembysimplycontacting.So,weproposetouseNFCasthesystemdriveinthearchitecture,suchthatuserscanintuitivelyinteractwiththesystemanddelivertheirintentions.Then,thecorrespondingserviceoverthesystemwillcontroloradjustthe"things"athometofitusers’needs.Furthermore,theproposedsystemprovidesaplatformfordeveloperstoeasilyandrapidlyimplementtheirsmarthomerelatedservices.Inthesystem,WSNsensingandcontrol,NFCcommunicationsandidentification,userprofilemanagementandpreferenceanalysis,andsocialnetworkintegrationareallprovidedasplatformservices.Wewillshowhowthesystemworksforhomeautomation,intruderdetection,andsocialnetworksharing.
简介:Thestabilityofthedrivecurrentisveryimportantforalaserdriver,whileitisdifficulttomaintainthecurrentstableatahighvalueforthelaserdriver.Ontheotherhand,therangeofthedrivecurrentisexpectedtobeaswideaspossibletobeappliedtodifferentkindsoflasers.Inthispaper,ahighcurrentlaserdriverforthesuperluminescentlightemittingdiode(SLED)ispresented,whichisusedintheopticfibergyroembeddedbya0.35mbipolarcomplementarymetal-oxide-semiconductortransistor(BiCMOS)process.Thelaserdriverprovidesautomaticpowercontrolandcertainvalueofcurrentdeterminedbytheexternalresister.Thesystemisbasedontheoptic-electricfeedbacktheoryandusestheclosed-loopcontroltechniquetomaintainthedrivecurrentstable.Thesystemiscapableofproducingstablecurrentrangesfrom4mAto200mAwhenthevalueofexternalresisterchanges.