学科分类
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129 个结果
  • 简介:Theradialbasisfunction(RBF)emergedasavariantofartificialneuralnetwork.Generalizedregressionneuralnetwork(GRNN)isonetypeofRBF,anditsprincipaladvantagesarethatitcanquicklylearnandrapidlyconvergetotheoptimalregressionsurfacewithlargenumberofdatasets.Hyperspectralreffectance(350to2500nm)datawererecordedattwodifferentricesitesintwoexperimentfieldswithtwocultivars,threenitrogentreatmentsandoneplantdensity(45plantsm-2).Stepwisemultivariableregressionmodel(SMR)andRBFwereusedtocomparetheirpredictabilityfortheleafareaindex(LAI)andgreenleafchlorophylldensity(GLCD)ofricebasedonreffectance(R)anditsthreedifferenttransformations,thefirstderivativereffectance(D1),thesecondderivativereffectance(D2)andthelog-transformedre?ectance(LOG).GRNNbasedonD1wasthebestmodelforthepredictionofriceLAIandGLCD.TherelationshipsbetweendifferenttransformationsofreffectanceandriceparameterscouldbefurtherimprovedwhenRBFwasemployed.Owingtoitsstrongcapacityfornonlinearmappingandgoodrobustness,GRNNcouldmaximizethesensitivitytochlorophyllcontentusingD1.ItisconcludedthatRBFmayprovideausefulexploratoryandpredictivetoolfortheestimationofricebiophysicalparameters.

  • 标签: 径向基函数神经网络 广义回归神经网络 生物物理参数 水稻 模型估算 高光谱反射率
  • 简介:Wepresenttwoschemesforpreparingremotelyathree-particleentangledstatebytwodifferentquantumchannels.Inthefirstscheme,twopartialthree-particleentangledstatesareusedasthequantumchannels,whileinthesecondscheme,threetwo-particlenon-maximallyentangledstatesareemployedasthequantumchannels.Itisshownthattheremotestatepreparationcanbesuccessfullyreal/zealwithcertainprobability,forbothtwoschemes,ifasenderperformssomeprojectivemeasurementsandareceiveradoptssomeappropriateunitarytransformations.Itisshownalsothatthesuccessfulprobabilitiesofthesetwoschemesaredifferent.

  • 标签: 量子论 纠缠 盖然论 投射测量
  • 简介:Areviewoften-year’spracticeindevelopingtheimprovedsimultaneousphysicalretrievalmethod(ISPRM)isgiveninthehopethatsomecreativeideascanbedrawnfromit.TheimprovementupontheSPRMisassociatedwiththeunder-determinednessofthisill-posedinverseproblem.Inourexperiment,thepreconditionisobservedthatpriorinformationmustbeindependentofthesatellitemeasurements.Thewell-posedretrievaltheoryhastoldusthattheforwardprocessisfundamentalfortheretrieval,anditisthebridgebetweentheinputofsatelliteradianceandtheoutputofretrievals.Inordertoobtainabetterresultfromtheforwardprocess.thefulladvantageofeverypriorinformationavailablemustbetaken.Itisnecessarytoturntheill-posedinverseproblemintothewell-posedone.ThenbyusingtheRidgeregressionorBayesalgorithmtofindtheoptimalcombinationamongthefirstguess,thetheoreticalanalogueinformationandthesatelliteobservations,theimpactoftheunder-determinednessofthisinverseproblemonthenumericalsolutionisminimized.

  • 标签: simultaneous physical RETRIEVAL model(SPRM) statistical regression
  • 简介:钇铝柘榴石的一个原型:Ce(Y3Al5O12)象为白带的照明的遥远的黄磷陶器的发光体积通过硅石增加的策略在空中被制作。与在一个特定的范围增加硅石的数量,不透明的样品转弯半透明。晶体的降水被验证在由X光检查衍射(XRD)的纯钇铝柘榴石阶段。在硅石数量的限制以外,钇铝柘榴石水晶的主导的阶段被发现与最新形成的Y2Si2O7,Al2O3和非结晶的阶段的小数量共存。钇铝柘榴石晶体与约2m的一种谷物尺寸并且均匀地散布。在经由在5d4f转变的黄乐队排放的硅石结果的增加的结构的修正以后的钇铝柘榴石主人在由带的蓝色激动的535nm附近达到顶点,由于到甚至当减少的空气不在时的Ce3+的Ce4+的自我减小。

  • 标签: YAG激光器 二氧化硅 陶瓷制备 热稳定性 空气 散装
  • 简介:摘要:随着我国经济的发展、社会的进步及城市化进程的加快,基础设施建设迅速发展,很多建设工程都对测绘产品提出了相应速度快、测绘精度高等要求。无人机遥感技术出现与发展,其在复杂的地形、高精度的测量任务中具有响应快、数据精度高等优点满足各类经济建设对测绘需求。基于此,以下对工程测量中无人机遥感技术的运用进行了探讨,以供参考。

  • 标签: 工程测量 无人机遥感技术 运用研究
  • 简介:PhysiographyandsoilinMaeRimwatershed,ChiangMaiProvince,Thailandwereinvestigatedbyusingaerialphotographsandsatelliteimageinconjunctionwithfieldwork,andsoilinfiltrationrateandsoilshearresistanceweremeasuredinfield.ManyfactorsaffectingrunoffwereanalyzedusigtheIntegratedLandandWaterInformaitonSystem(ILWIS).Asaresult,amodeldeterminingfloodhazarwassetup.Threempsincludingrunoffcurvenumbermap,runoffcoefficentmap,andfloodinumdationmapwerecreated,Inaddition,thetimeofconcentrationwaspredicted.

  • 标签: 洪水危害预报 遥感 地理信息系统 土壤性质 表面流失系数 泰国
  • 简介:ThestudyprovidesoneofthefirstlinesofevidenceshowinglinkagesbetweenAntarcticphytoplanktonabundanceandcompositioninresponsetoENSO,basedonhistoricalreconstructionofsedimentbiomarkers.Inadditiontosedimentbiomarkers,fieldmeasuredandremotesensingdataofphytoplanktonabundancewerealsorecordedfromPrydzBay,EasternAntarctica.CommunitystructureoffieldmeasuredphytoplanktonshowedsignificantElNino/LaNina-relatedsuccessionduring1990to2002.Ingeneral,thenumberofalgaespeciesdecreasedduringElNinoandLaNinayearscomparedtonormalyears.Australsummermonthlyvariationofremotelysensedchlorophyll-a(Chl-a),particulateorganiccarbon(POC),andseasurfacetemperature(SST)indicatedthatENSOimpactedthetimingofphytoplanktonbloomsduring2007to2011.Phytoplanktonblooms(indicatedbyChl-aandPOC)precededtheincreasesinSSTduringElNinoyears,andlaggedbehindtheSSTincreasesduringLaNinayears.Stratigraphicrecordofmarinesedimentarylipid(brassicasterol,dinosterolandalkenones)biomarkersinferredthattheproportionsofdifferentalgae(diatoms,dinoflagellatesandhaptophytes)changedsignificantlybetweenElNinoandLaNinaevents.Therelativeproportionofdiatomsincreased,withthatofdinoflagellatesbeingdecreasedduringElNinoyears,whileitwasreversedduringLaNinayears.

  • 标签: ENSO事件 南极普里兹湾 生物标志物 浮游植物 遥感数据 现场测量
  • 简介:摘要:本文通过对无人机遥感技术在测绘工程中的应用过程分析,阐述了无人机遥感技术在测绘工程应用中的优势及测绘技术人员在实际操作过程中应注意的问题,肯定了无人机遥感技术在测绘技术发展中的推动作用。

  • 标签: 无人机遥感技术 测绘工程 测绘技术
  • 简介:ThisbookistheproceedingsoftheNATOAdvancedScienceInstitute“RemoteSensingofProcessesGoverningEnergyandWaterCyclesintheClimateSystem”,heldinPln,Germany1—12May1995.Inthisbook,atotalof21conferencepapersareincludedwithaspecialpartforpostersummaries.Allthepapersaremodifiedorshortenversions

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