简介:Thewirelesssensornetwork(WSN)consistsofsensornodesthatinteractwitheachothertocollectivelymonitorenvironmentalorphysicalconditionsatdifferentlocationsfortheintendedusers.Oneofitspotentialdeploymentsisintheformofsmarthomeandambientassistedliving(SHAAL)tomeasurepatientsorelderlyphysiologicalsignals,controlhomeappliances,andmonitorhome.ThispaperfocusesonthedevelopmentofawirelesssensornodeplatformforSHAALapplicationoverWSNwhichcomplieswiththeIEEE802.15.4standardandoperatesin2.4GHzISM(industrial,scientific,andmedical)band.TheinitialstageofSHAALapplicationdevelopmentisthedesignofthewirelesssensornodenamedTelGmote.ThemainfeaturesofTelGmotecontributingtothegreencommunicationsincludelowpowerconsumption,wearable,flexible,user-friendly,andsmallsizes.Itisthenembeddedwithaself-builtoperatingsystemnamedWiseOStosupportcustomizedoperation.Thenodecanachieveapacketreceptionrate(PRR)above80%foradistanceofupto8m.ThedesignedTelGmoteisalsocomparablewiththeexistingwirelesssensornodesavailableinthemarket.
简介:Tofindtheoptimalroutingisalwaysanimportanttopicinwirelesssensornetworks(WSNs).ConsideringaWSNwherethenodeshavelimitedenergy,weproposeanovelEnergy*Delaymodelbasedonantalgorithms('E&DANTS'forshort)tominimizethetimedelayintransferringafixednumberofdatapacketsinanenergy-constrainedmannerinoneround.Ourgoalisnotonlytomaximizethelifetimeofthenetworkbutalsotoprovidereal-timedatatransmissionservices.However,becauseofthetradeoffofenergyanddelayinwirelessnetworksystems,thereinforcementlearning(RL)algorithmisintroducedtotrainthemodel.Inthissurvey,theparadigmofE&DANTSisexplicatedandcomparedtootherant-basedroutingalgorithmslikeAntNetandAntChainabouttheissuesofroutinginformation,routingoverheadandadaptation.SimulationresultsshowthatourmethodperformsaboutseventimesbetterthanAntNetandalsooutperformsAntChainbymorethan150%intermsofenergycostanddelayperround.
简介:为紧张和温度测量的一个光纤维传感器与纤维基于长时期纤维栅栏(LPFG)串联了布拉格栅栏(FBG)结构理论上并且试验性地被建议了并且认识到。有类似的敏感的二微观结构不能被用于的理论分析表演加倍参数测量。LPFG是由CO2激光的micromachined,并且FBG是由excimer激光的micromachined。为确认和比较,二FBG和一LPFG与三条传播山谷被串联,也就是在1536.3nm,在1551.2nm的LPFG山谷,和在1577.3nm的FBG2山谷的FBG1山谷。建议传感器的温度和紧张特征在4570椠歮愠獢牯敢獲愠敲映物瑳祬搠瑥牥業敮?桴潲杵?桰瑯慯潣獵楴?湡?灳'虪沟茲滀髷疇罐鏇V畳敲敭瑮?瑡琠敨猠浡?被测量硥楣慴楴湯?桷捩?敤潭獮牴瑡獥琠敨映慥楳楢楬祴漠?桴獩洠瑥潨d
简介:Modifiedsensingmembranesbasedonfluorescencequenchingwerepreparedbythesol-gelmeth-od,usingformamideasthedryingcontrolchemicaladditive,tetraethoxysilaneasthemainmaterial,Ru(phen)3Cl2astheindicator.Themembranewiththeoptimumthicknessof20-50μmisuniformandcrack-free,inwhichtheindicatorhasaverysmallleakingrate.Themembraneisimmersedinwaterfor50h,themembranesensingparameterMdecreasesbylessthan5%.Thefiberopticoxygensensorwiththesensingmembranehasadetectionlimitof5×10-6M(ppm),aresponsetimeoflessthan30s,excellentreproducibilityandstability.
简介:Duetothelargescaleandcomplexityofcivilinfrastructures,structuralhealthmonitoringtypicallyrequiresasubstantialnumberofsensors,whichconsequentlygeneratehugevolumesofsensordata.Innovativesensordatacompressiontechniquesarehighlydesiredtofacilitateefficientdatastorageandremoteretrievalofsensordata.ThispaperpresentsavibrationsensordatacompressionalgorithmbasedontheDifferentialPulseCodeModulation(DPCM)methodandtheconsiderationofeffectsofsignaldistortionduetolossydatacompressiononstructuralsystemidentification.TheDPCMsystemconcernedconsistsoftwoprimarycomponents:linearpredictorandquantizer.FortheDPCMsystemconsideredinthisstudy,theLeastSquaremethodisusedtoderivethelinearpredictorcoefficientsandJayantquantizerisusedforscalarquantization.A5-DOFmodelstructureisusedastheprototypestructureinnumericalstudy.NumericalsimulationwascarriedouttostudytheperformanceoftheproposedDPCM-baseddatacompressionalgorithmaswellasitseffectontheaccuracyofstructuralidentificationincludingmodalparametersandsecondorderstructuralparameterssuchasstiffnessanddampingcoefficients.ItisfoundthattheDPCM-basedsensordatacompressionmethodiscapableofreducingtherawsensordatasizetoasignificantextentwhilehavingaminoreffectonthemodalparametersaswellassecondorderstructuralparametersidentifiedfromreconstructedsensordata.
简介:Asimplelayer-by-layerdepositiontechniquewasusedtofabricatethemultilayerthinfilmsofunmodifiedsilvertriangularnanoplates(AgTNPs).ThemultilayerofAgTNPsthinfilmswerefabricatedbyalternatedepositionofeachanionicsodiumcitratestabilizedAgTNPsandcationicpoly(diallyldimethylammoniumchloride).AllpreparedAgTNPsmultilayerthinfilmswereexhibitedastrongplasmonbandatthewavelengthof667nm,whichconfirmedtheformationofAgTNPsontothesubstrate.Thecharacteristicsofthemultilayerthinfilmswereinvestigatedusingcontactanglemeasurement,UV-visiblespectroscopy,X-raydiffractionanalysis(XRD),atomicforcemicroscope(AFM)andfieldemissionscanningelectronmicroscope(FESEM).Asthesefilmsaretobeusedasamercury(II)colorimetricsensor,thechangesinopticalpropertiesofthefilmswereevaluatedforvariousmercury(Ⅱ)concentrations.AgTNPsassembledintothinfilmsshowedastrongcolorshiftfrombluetomauveandcolorlesswhenexposedtomercury(Ⅱ).Theconstructedmultilayerthinfilmsexhibitedexcellentcolorchangesofmercury(II)withalinearrangebetween0.5and20ppm.Thelimitofdetection(LOD)andlimitofquantitation(LOQ)were0.45±0.002and1.52±0.002ppm,respectively.TherecoveryvaluesofAgTNPsmultilayerthinfilmsaresatisfactoryintherangeof100.1%-106.4%whenappliedtodeterminingmercury(Ⅱ)inwatersamples.
简介:ThelocalCa^2+releasefromtheheterogeneouslydistributedendoplasmicreticulum(ER)calciumstorehasacriticalroleincalciumhomeostasisandcellularfunction.However;singlefluorescentproteinbasedERcalciumprobesexperiencechallengesinquantifyingtheERcalciumstoreindifferinglivecells,andintensity-basedmeasurementsmakeitdifficulttodetectlocalcalciummicrodomainsintheER.Here,wedevelopedageneticallyencodedratiometricERcalciumindicator[GCEPIA1-SNAPer]thatcandetectthereal-timeERcalciumstoreandlocalcalciummicrodomainsinlivecells.GCEPIA1-SNAPerwaslocatedinthelumenoftheERandshowedalinear;reversibleandrapidresponsetochangesintheERcalciumstore.TheGCEPIA1-SNAPerprobeeffectivelymonitoredthedepletionoftheERcalciumstorebyTGorstarvationtreatment,andthrough让suseweidentifiedheterogeneouslydistributedcalciummicrodomainsintheERwhichwerecorrelatedw让hthedistributionofSTIM1clustersuponERcalciumstoredepletion.Lastly,GCEPIA1-SNAPercanbeusedtodetecttheERcalciumstorebyhigh-throughputflowcytometryandconferstheabilitytostudythefunctionofcalciummicrodomainsoftheER.
简介:Underwatersensornetwork(UWSN)adoptsacousticcommunicationwithmoreenergy-consumptionandlongerpropagation-delay,whichbringgreatchallengestoprotocoldesign.Inthispaper,weproposedlevel-basedadaptivegeo-routing(LB-AGR)protocol.LB-AGRdividestrafficsintofourcategories,androutesdifferenttypesoftrafficinaccordancewithdifferentdecisions.Packetsupstreamtothesinkareforwardedunicasttothebestnext-hopinsteadofbroadcastingtoallneighbornodesasinpresentUWSNroutingprotocols.LB-AGRdefinesanintegratedforwardingfactorforeachcandidatenodebasedonavailableenergy,density,location,andlevel-differencebetweenneighbornodes,whichisusedtodeterminethebestnext-hopamongmultiplequalifiedcandidates.Throughsimulationexperiments,weshowthepromisingperformanceofLB-AGR.
简介:Anultrasensitivemagneticfieldsensorbasedonacompactin-fiberMach–Zehnderinterferometer(MZI)createdintwin-corefiber(TCF)isproposed,anditsperformanceisexperimentallydemonstrated.AsectionofTCFwassplicedbetweentwosectionsofstandardsingle-modefibers,andthenamicrochannelwasdrilledthroughonecoreoftheTCFbymeansoffemtosecondlasermicromachining.TheTCFwithonemicrochannelwasthenimmersedinawater-basedFe3O4magneticfluid(MF),formingadirectcomponentofthelightpropagationpath,andthensealedinacapillarytube,achievingamagneticsensingelement,whichmergestheadvantagesofanMZIwithanMF.Experimentswereconductedtoinvestigatethemagneticresponseoftheproposedsensor.Thedevelopedmagneticfieldsensorexhibitsalinearresponsewithinameasurementrangefrom5to9.5mTandanultrahighsensitivityof20.8nm/mT,which,toourbestknowledge,is2ordersofmagnitudegreaterthanotherpreviouslyreportedmagneticsensors.Theproposedsensorisexpectedtooffersignificantpotentialfordetectingweakmagneticfields.
简介:Inthispaperthesolar-blindultraviolet(UV)lightisusedascommunicationmediumforwirelesssensornetworks(WSNs).ThreetypesofsinglescatteringUVcommunicationmodelsareintroducedandadirectionalfloodingmodelisproposed,whicharebasedonthedirectionalityoftheUVcommunicationandthetraditionalfloodingroutingmodel.Thedelay,delayjitter,throughputandenergyconsumptionofthethreetypesofcommunicationsofthenewmodelaresimulatedandcompared.Theresultsindicatethattheproposeddirectionalfloodingmodelcaneffectivelyavoidtheunidirectionalityandtheblindnessofthetraditionalfloodingbroadcastmessages.Theenergyconsumptionofnodesinthenetworkisreducedandthelifecycleofthenetworkisextended.
简介:Thispaperpresentsacollaborativebeamforming(CB)techniquetoorganizethesensornode'slocationinalineararrayforgreenwirelesssensornetwork(WSN)applications.Inthismethod,onlyselectedclustersandactiveCBnodesareneededeachtimetoperformCBinWSNs.Theproposedleast-squarelineararray(LSLA)managestoselectnodestoperformasalinearantennaarray(LAA),whichissimilartoandasoutstandingastheconventionaluniformlineararray(ULA).TheLSLAtechniqueisalsoabletosolvepositioningerrorproblemsthatexistintherandomnodesdeployment.Thebeampatternfluctuationshavebeenanalyzedduetotherandompositionsofsensornodes.Performancesintermsofnormalizedpowergainsaregiven.ItisdemonstratedbyasimulationthattheproposedtechniquegivessimilarperformancestotheconventionalULAandatthesametimeexhibitslowercomplexity.
简介:Aschemeisproposedtoelevatethelimitationofthegroundapplicationsystemofmono-satellite-sensorundertherequirementofremotesensingsatellitegroundapplicationsystem.Intheresource-sharing,forinstancecaculatingresource,asimplephototypeofcaculating-resourceisproposedthroughanalyzingresourceassignment,applicationassignment,bodystructure,andsoon.Inordertoimprovetheabilityofassignment,realizethefavorableutility,management,andmaintenance,thephototypeisimprovedbyusingdatagridcalculationaccordingtotherequirementandcharacterofactualapplication.Thephototypecanbetakenasthefoundationofcalculationframeofremotesensinggroundapplicationsystemofmulti-satelliteandmulti-sensor.
简介:Inexperimentalstudyofthetindioxidegassensor,insitusheetconductivitywasmeasuredwithultrahighvacuumfourpointresistivityprobe.Surfacecompositionandstoi-chiometryweredetectedusingXPS.FourseparatestructurephaseswereobtainedbyLEEDatdifferentannealingtemperature,andemissionwasobservedthroughoutthebandgapuptotheFermilevelwithUPS.Furthermore,effectsofannealingtemperatureanddosedoxygenpressureonthesurfacereconstruction,O/Snratio,sheetconductivity,variationoftheworkfunctionandbandbendinghavebeenalsoinvestigated.Theresultshelpustorevealtherelationshipsbetweentheelectronicandelectricalpropertiesofthematerialanditsnativedefectsstructure.Itises-peciallyusefultoprovideamorecompleteunderstandingofthebasicoperationmechanismsforsuchsensingmaterials.