简介:Atpresent,mostunderwaterpositioningalgorithmsimprovethepositioningaccuracybyincreasingthenumberofanchornodeswhichresultingintheincreasingenergyconsumption.Tosolvethisproblem,thepaperproposesalocalizationalgorithmassistedbymobileanchornodeandbasedonregiondetermination(LMRD),whichnotonlyimprovesthepositioningaccuracyofnodespositioningbutalsoreducestheenergyconsumption.Thisalgorithmisdividedintotwostages:regiondeterminationstageandlocationpositioningstage.Intheregiondeterminationstage,thetargetregionisdividedintoseveralsub-regionsbytheregiondivisionstrategywiththesmallestoverlapratewhichcanreducethenumberofvirtualanchornodesandlockthetargetnodetoasub-region,andthenthroughtheplanningofmobilenodestooptimizethetravelpath,reducethemovingdistance,andreducesystemenergyconsumption.Inthelocationpositioningstage,thetargetnodelocationcanbecalculatedusingtheHILBERTpathplanningandtrilateration.Thesimulationresultsshowthattheproposedalgorithmcanimprovethepositioningaccuracywhentheenergyconsumptionisreduced.
简介:Adoublycladdingsingle-modefiberhumiditysensorisfabricatedbyagarose.Thesensorhasaninsertionlossof0.08dBandapowerchangeof17.83dB.Theresponsesofthesensortoarelativehumidity(RH)rangeform30%to100%atatemperaturerangeform25to34Carevalidated.TheexperimentsdemonstratethattheabsorbabilityofagarosegeltomoisturedecreaseswithincreasingRHinmeasuredgas.Weproposeacalibrationmethodthatuseslookuptablesandconstructacorrespondingcalibrationmatrix.Usingthesensor,weconductreal-timemonitoringofRHinfreshconcreteduringitshardeningprocess.
简介:AMonteCarloAnalysisofnodesdeploymentforlarge-scaleandnon-homogeneouswirelesssensornetworks,hasbeendone.Throughsimulationsofrandomdeploymentsofnodesoverasquareareausingdifferentdensities,assumingthatournetworkiscomposedbyAnchornodes(specialsensorswithknownposition)andsimpleSensornodes,thelatteraresupposedtoestimatetheirownpositionafterbeingplacedwithinthecoverageareawiththeminimumAnchornodesneededto'feed'themwiththenecessaryinformation.Thegoalisthentoassistdecision-makersinselectingamongdifferentalternativestodeploythenetworks,accordingtoresourcesfeaturesandavailability,hencethismethodprovidesanestimatevalueofhowmanyAnchornodesshouldbedeployedinagivenareatotriggerthelocationalgorithminthegreatestpossiblenumberofSensornodesinthenetwork.
简介:Byusingagraded-indexmultimodefiber(GI-MMF)witharelativelyflatindexprofileandhighrefractiveindexofthefibercore,amicroextrinsicfiber-opticFabryProtinterferometric(MEFPI)strainsensorisfabricatedthroughchemicaletchingandfusionsplicing.Higherreflectanceofthemicrocavityisobtainedduetotheless-curvedinnerwallinthecenterofthefibercoreafteretchingandhigherindexcontrastbetweentheGI-MMFcoreandair.Themaximumreflectionofthesensorisenhanced12dBthanthatobtainedbyetchingoftheEr-orB-dopedfibers.Highfringecontrastof22dBisobtained.ThestrainandtemperatureresponsesoftheMEFPIsensorsareinvestigatedinthisexperiment.Goodlinearityandhighsensitivityareachieved,withwavelength-strainandwavelength-temperaturesensitivitiesof7.82pm/μεand5.01pm/°C,respectively.
简介:Foranintegratedelectro-opticalsensor,theoperatingpointhasasignificanteffectontheperformanceofthesensor.Inthispaper,anopticalwaveguideelectricfieldsensorwithcontrollableoperatingpointisdesignedusingLiNbO3materials,whichhasanasymmetricMach-Zehnderinterferometer(MZI)structure.Theoreticalresultsshowthattheoptimaloperatingpointcanbeobtainedandcontrolledbytuningtheoutputwavelengthofthetunablelaserusedinthesensingsystem.Thesimulationresultsshowthatthesensitivityabout83dB·μV/mcanbeobtained,andthelineardynamicrangeaslargeas60dBcanbeachieved.Andthefabricationtoleranceofthecenter-to-centerdistanceforthe3dBcouplerusedintheasymmetricMZIis~0.5μm,whilethepowersplittingratiooftheYbranchiswithmoretolerance.
简介:定位一个目标的一个有效解决方案被建议,由使用到达(TDOA)的时差,大小它面对随机的传感器放错误增加评价的精确性。在二阶段的加权的最少的广场(TSWLS)的位置评价错误的原因方法被分析为改进本地化表演开发一个简单、有效的方法。明确地,参考传感器再被选择,坐标系统被使用TSWLS方法,和目标的最后的位置评价根据初步的估计的目标位置旋转被使用加权的最少的广场(WLS)获得。建议途径展览一靠近形式并且象TSWLS一样有效方法。模拟结果证明建议途径与增加传感器位置错误产出低评价偏爱和改进坚韧性并且能容易因此容易完成Cramer-Rao更低的界限(CRLB)并且有效地改进本地化精确性。
简介:Aplasmonicrefractiveindexsensorbasedonmetal-insulator-metal(MIM)waveguide-coupledstructureisproposedanddemonstratedinthispaper.Thephysicalmechanismofthedeviceisdeduced,andthefinitedifferencetimedomain(FDTD)methodisemployedtosimulateandstudyitsindexsensingcharacteristics.Bothanalyticandsimulatedresultsshowthattheresonantwavelengthofthesensorhasalinearrelationshipwiththerefractiveindexofmaterialundersensing.Basedontherelationship,therefractiveindexofthematerialcanbeobtainedfromthedetectionoftheresonantwavelength.Theresultsshowthatthesensitivityofthesensorcanexceed1600nm/RIU,anditcanbeusedinchemicalandbiologicaldetections.
简介:Theproblemofair-fuelratio(AFR)controloftheportinjectionsparkignition(SI)engineisstillofconsiderableimportancebecauseofstringentdemandsonemissioncontrol.Inthispaper,thestaticAFRcalculationmodelbasedonin-cylinderpressuredataandontheadaptiveAFRcontrolstrategyispresented.Themodelutilisestheintakemanifoldpressure,enginespeed,totalheatrelease,andtherapidburnangle,asinputvariablesfortheAFRcomputation.Thecombustionparameters,totalheatrelease,andrapidburnangle,arecalculatedfromin-cylinderpressuredata.ThisproposedAFRmodelcanbeappliedtothevirtuallambdasensorforthefeedbackcontrolsystem.Inpracticalapplications,simpleadaptivecontrol(SAC)isappliedinconjunctionwiththeAFRmodelforport-injectedfuelcontrol.TheexperimentalresultsshowthattheproposedmodelcanestimatetheAFR,andtheaccuracyoftheestimatedvalueisapplicabletothefeedbackcontrolsystem.Additionally,theadaptivecontrollerwiththeAFRmodelcanbeappliedtoregulatetheAFRoftheportinjectionSIengine.
简介:处于正常操作条件,一个常规方形根的求容积法Kalman过滤器(SRCKF)给足够地好的评价结果。然而,如果大小不是可靠的,SRCKF可以给不精密的结果并且到时间分叉。这研究与过滤器获得修正介绍一个适应SRCKF算法因为测量的盒子失灵。由建议一个切换的标准,一个最佳的过滤器根据测量质量从适应、常规的SRCKF被选择。一个分系统软差错察觉算法与过滤器剩余被造。利用一个清楚的分系统差错系数,有缺点的分系统由于系统重建被孤立。以便改进多传感器系统的性能,一个混合熔化算法基于适应SRCKF被介绍。状态和错误协变性矩阵被priori熔化估计也预言,并且被分系统的预言并且估计的信息更新。建议算法被用于容器动态放系统模拟。他们与正常SRCKF和本地评价相比是加权的熔化算法。模拟结果证明介绍适应SRCKF改进分系统过滤的坚韧性,并且混合熔化算法有更好的表演。模拟验证建议算法的有效性。
简介:(FRS2)成纤维细胞生长因素(FGF)受体底层2是在FGF小径发信号的主要调停人。最近的研究在FRS2显示出那激活mitogen的蛋白质kinase(MAPK)phosphorylates丝氨酸和threonine残余,否定地影响FRS2的导致FGF的酷氨酸phosphorylation(PY)。几种刺激能导致FRS2的serine/threoninephosphorylation(PS/T),显示FRS2可能为学习在表明小径的生长因素之间的串音是有用的。这里,我们报导FRS2的导致FGF的PY能被EGF合作刺激在PC12房间稀释;这禁止的效果能被U0126完全颠倒,MEK的一个禁止者。我们进一步在FRS2识别了ERK1/2-binding主题并且在FGF或EGF刺激之上产生了FRS2-3KL,变异的缺乏MAPK绑定和磅。不同野类型(WT)FRS2,FRS2-3KL的导致FGF的PY不能被EGF合作刺激,和更展出的FRS2-3KL-expressingPC12房间禁止响应FGF处理比FRS2-WT-expressing房间区分潜力。这些结果建议FRS2的PS/T由FRS2-MAPK否定规章的循环调停了可以作为从另外的小径把否定规章的信号集成到产生FGFR的信号transduction的一个分子的开关工作。
简介:AhighsensitivityD-shapedholedouble-claddingfibertemperaturesensorbasedonsurfaceplasmonresonance(SPR)isdesignedandinvestigatedbyafull-vectorfiniteelementmethod.WithintheD-shapedholedoublecladdingfiber,thehollowD-sectioniscoatedwithgoldfilmandtheninjectedinahighthermo-opticcoefficientliquidtorealizethehightemperaturesensitivityforthefiberSPRtemperaturesensor.ThenumericalsimulationresultsshowthatthepeakinglossoftheD-shapedholedouble-claddingfiberSPRishugelyinfluencedbythedistancebetweentheD-shapedholeandfibercoreandbythethicknessofthegoldfilm,butthetemperaturesensitivityisalmostinsensitivetotheaboveparameters.Whenthethermo-opticcoefficientis-2.8×10-4∕℃,thethicknessofthegoldfilmis47nm,andthedistancebetweentheD-shapedholeandfibercoreis5μm,thetemperaturesensitivityoftheD-shapedholefiberSPRsensorcanreachto-3.635nm∕℃.
简介:Low-duty-cyclemechanismscanreducetheenergyconsumptionsignificantlyinwirelesssensornetworks(WSNs).Sensorsstaydormantmostofthetimetosavetheirenergyandwakeupbasedontheirneeds.However,suchatechnique,whileprolongingthenetworklifetime,setsexcessivechallengesforreducingtheend-to-end(E2E)delaywithinthenetwork.Inthispaper,thecentralizedcluster-basedlocationfinding(CCLF)algorithmisproposedtoreducethehighlatencyinlow-duty-cycleWSNsbyfindingasuitablepositionforthesink.Thealgorithmismainlycomposedofthreesteps:a)theclusterconstruction,b)thefastlook-uptable(FLU-table)construction,andc)thesinklocationdecision.ThesimulationresultsshowthattheperformanceoftheCCLFalgorithmissignificantlysimilartothatoftheoptimalalgorithm.Moreover,theCCLFalgorithmrequireslessoperationtimecomparedwiththeoptimalalgorithm.
简介:为了在无线传感器网络(WSN)完成安全通讯,在有有限计算能力的传感器节点随机在敌对领土上被散布的地方,各种各样的关键分发前策划(KPS)被建议了。在这份报纸,新KPS在有限的地上基于symplectic几何学被建议。在一个symplectic空格的固定维的subspace代表一个节点,所有1-dimensionalsubspaces表示钥匙和每个节点分享了钥匙。但是这天真的印射不保证一个好网络得到跳回。因此,它被建议二个节点不得不计算一把pairwise钥匙的提高的KPS,仅当他们分享至少q普通钥匙。这条途径对节点俘获攻击提高跳回。与解决方案的存在相比,结果证明那条新途径更加提高网络可伸缩性,并且完成好连接和好全面性能。
简介:ThestatisticalcharacterofQuikSCATscatterometerwindsisshowed.AndMonthlychangeandspecialdistributioncharacterofstrongwindfrequencyandmonthlywindfieldsinSouthChinaSeaisanalyzed.ItisshownintheresultthattheQuikSCATscatterometerwindscanberelieduponfortheSouthChinaSea;twowinds,onethewintertimenortheasterlyandtheothersummertimesouthwesterly.ThenortheasterlycentersattheBashiStraitandTaiwamStraitanditssecondarycenterandthemaximumcenterofthesouthwesterlyareinthecentralandsouthernSouthChinaSea.
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简介:Weproposeahighsensitivitysensorbasedonamodenumber-encodedmulti-longitudinalmodefiberlaser.ThefiberlaserincorporatesauniformfiberBragggrating(FBG)andafiberFabry-Perotinterferometer(FFPI)assensitivecomponentsinthecavity.Thesensorcountsthenumberoflongitudinalmodes(NLM)offiberlaser,whichiscausedbythemismatchbetweenthereflectionbandofFBGandthetransmissionbandofFFPIresultingfromtheapplicationofexternalperturbationtotheFBG.AnelectricalspectrumanalyzerisadoptedtoanalyzetheNLM.Thestrainsensorisexperimentallydemonstratedtohavesensitivityofashighas0.02με/mode.