学科分类
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7 个结果
  • 简介:WiththedevelopmentofCMOSandMEMStechnologies,theimplementationofalargenumberofwirelessdistributedmicro-sensorsthatcanbeeasilyandrapidlydeployedtoformhighlyredundant,self-configuring,andadhocsensornetworks.Tofacilitateeaseofdeployment,thesesensorsoperateonbatteryforextendedperiodsoftime.Aparticularchallengeinmaintainingextendedbatterylifetimeliesinachievingcommunicationswithlowpower.Forbetterunderstandingofthedesigntradeoffsofwirelesssensornetwork(WSN),amoreaccurateenergymodelforwirelesssensornodeisproposed,andanoptimaldesignmethodofenergyeffcientwirelesssensornodeisdescribedaswell.DifferentfrompowermodelsevershownwhichassumethepowercostofeachcomponentinWSNnodeisconstant,thenewonetakesintoaccounttheenergydissipationofcircuitsinpracticalphysicallayer.Itshowsthattherearesomeparameters,suchasdatarate,carrierfrequency,bandwidth,Tsw,etc,whichhaveasignificanteffectontheWSNnodeenergyconsumptionperusefulbit(EPUB).Foragivenqualityspecification,howenergyconsumptioncanbereducedbyadjustingoneormoreoftheseparametersisshown.

  • 标签: WSNS 能量模式 最优设计 通信技术
  • 简介:HippocampalvolumelossisanimportantbiomarkerindistinguishingsubjectswithAlzheimer’sdisease(AD)anditsmeasurementinmagneticresonanceimages(MRI)isinfluencedbypartialvolumeeffects(PVE).Thispaperdescribesapost-processingapproachtoquantifyPVEforcorrectionofthehippocampalvolumebyusingaspatialfuzzyC-means(SFCM)method.Thealgorithmisevaluatedonadatasetof20T1-weightedMRIscanssampledattwodifferentresolutions.Thecorrectedvolumesforleftandrighthippocampus(HC)whichare23%and18%forthelowresolutionand6%and5%forthehighresolutiondatasets,respectivelyarelowerthanhippocampalvolumeresultsfrommanualsegmentation.ResultsshowtheimportanceofapplyingthistechniqueinADdetectionwithlowresolutiondatasets.

  • 标签: 体积损失 容积效应 准确测量 海马 阿尔茨海默氏病 高分辨率
  • 简介:ThispaperderivestheLindellformulabasedonthegeneralizedvariationalprinciple.ForthecomplexdielectricconstantmeasurementofasmalllossydielectricrodwithRayleigh-Ritzmethod,anaccuratevariationalanalysisisgiven.Theconceptofcomplexfrequencyisintroducedingeneral,andthestabilityofthesolutionisdiscussed.Comparingwiththeresultofperturbationmethod,itisconcludedthatthedeviationofperturbationalgorithmshouldbetakenintoconsideration.

  • 标签: General VARIATIONAL principle Lindell FORMULATION Complex
  • 简介:在这份报纸,结果在导致激光的故障光谱学(解放)的第一应用上被介绍为在alpha石蜡的Mg集中的量的决心的技术。这种技术在与传统的方法的那些可比较的Mg集中给精确性,这被表明,作为ICP-OES,在短时间并且没有对样品准备的需要。为500ppb的顺序的Mg的察觉的限制被表明。而且,关于合适的刻度曲线和察觉(LOD)的限制的定义的实现的简短讨论被报导。CLC数字TP274

  • 标签: α-石蜡 镁含量 精确测量 激光诱导击穿光谱
  • 简介:MonteCarlosimulationofthediffusingtemporallightcorrelationinamulti-layeredturbidmediumisconsidered.Astraightforwardformulaisintroducedtocalculateaccuratelyandefficientlytheautocorrelationfunctionatanydetectorposition.Thesimulationresultsareinanexcellentagreementwithananalyticalsolutionofthecorrelationdiffusionequation.

  • 标签: 光学性质 衍射 传播方程 自相关函数 传播介质
  • 简介:Thepaperfirstdiscussesshortcomingsofclassicaladjacent-framedifference.Secondly,basedontheimageenergyandhighorderstatistic(HOS)theory,backgroundreconstructionconstraintsaresetup.Underthehelpofblock-processingtechnology,backgroundisreconstructedquickly.Finally,backgrounddifferenceisusedtodetectmotionregionsinsteadofadjacentframedifference.TheDSPbasedplatformtestsindicatethebackgroundcanberecoveredlosslesslyinaboutonesecond,andmovingregionsarenotinfluencedbymovingtargetspeeds.Thealgorithmhasimportantusagebothintheoryandapplications.

  • 标签: MOTION DETECTION BACKGROUND reconstruction Image energy