简介:Single-cameramobile-visioncoordinatemeasurementisoneoftheprimarymethodsof3D-coordinatevisionmeasurement,andcodedtargetplaysanimportantroleinthissystem.Amultifunctionalcodedtargetanditsrecognitionalgorithmisdeveloped,whichcanrealizeautomaticmatchoffeaturepoints,calculationofcamerainitialexteriororientationandspacescalefactorconstraintinmeasurementsystem.Theuniquenessandscalabilityofcodingareguaranteedbytherationalarrangementofcodebits.Therecognitionofcodedtargetsisrealizedbycross-ratioinvariancerestriction,spacecoordinatestransformoffeaturepointsbasedonspacialposeestimationalgorithm,recognitionofcodebitsandcomputationofcodingvalues.Theexperimentresultsdemonstratetheuniquenessofthecodingformandthereliabilityofrecognition.
简介:Thispapercombinescompressedsensing(CS)imagingtheoryandrangemigrationalgorithm(RMA),andthenproposesanear-fieldthree-dimensional(3-D)imagingapproachforjointhigh-resolutionimagingandphaseerrorcorrection.Firstly,asparsemeasurementmatrixconstructionmethodbasedonalogisticsequenceisproposed,whichconductsnonlineartransformationforthedeterminedlogisticsequence,makingitobeyuniformdistribution,thenconductssignfunctionmapping,andgeneratesthepseudorandomsequencewithBernoullidistribution,thusleadingtogoodsignalrecoveryunderdown-samplingandeasyavailabilityforengineeringrealization.Secondly,incombinationwiththeRMAimagingapproach,thedictionarywithallsceneinformationandphaseerrorcorrectionisconstructedforCSsignalrecoveryanderrorcorrection.Finally,thenon-quadraticsolutionmodeljointingimagingandphaseerrorcorrectionbasedonregularizationisbuilt,anditissolvedbytwosteps—theseparablesurrogatefunctionals(SSF)iterativeshrinkagealgorithmisadoptedtorealizetargetscatteringestimate;theiterationmodeisadoptedforthecorrectionofthedictionarymodel,soastoachievethegoaloferrorcorrectionandhighly-focusedimaging.Theproposedapproachprovestobeeffectivethroughnumericalsimulationandrealmeasurementinanechoicchamber.Theresultsshowthat,theproposedapproachcanrealizehigh-resolutionimaginginthecaseoflessdata;thedesignedmeasurementmatrixhasbetternon-coherenceandeasyavailabilityforengineeringrealization.Theproposedapproachcaneffectivelycorrectthephaseerror,andachievehighly-focusedtargetimage.
简介:滤波器在射频、微波电路中发挥重要作用。不断出现的无线通讯系统应用对滤波器提出了前所未有的挑战:更高的性能指标、更小的尺寸质量、更低的成本已成为新型滤波器必须满足的基本要求。援引了一个Ka波段Hairpin耦合结构的双通带滤波器原型,每一个耦合支的长度大约为两个通带中心频率对应的四分之一波长。然后基于PSO算法和IE3D仿真软件对滤波器进行优化,优化的最终结构体积很小,其大小仅为5.5mm×2.7mm,但两个通带的插入损耗仅相差0.5dB;另一方面,两个带内的S11都下降到了-28dB左右,最终生成了微带滤波器的版图。
简介:文章介绍了一种基于ARM、DSP和FPGA体系结构的3G-TD移动终端基带信号处理器。该系统能灵活实现移动通信系统中基带信号的各种处理,通过无线信号实现移动终端同基站之间的发送与接收,而且能够与不同基站之间信号进行切换。同时也给出了该系统的硬件设计、软件设计及其应用。并且满足标准兼容和客户对于功能改善、成本和电池寿命的需求。
简介:UnipolarresistiveswitchingbehaviorsoftheZnOandAl2O3/ZnOfilmsfabricatedonflexiblesubstratesbypulselaserdepositionwerestudiedinthispaper.Thefilmsweredepositedatroomtemperaturewithoutpost-annealingtreatmentduringtheprocess.XraydiffractionresultsindicatedthatZnOfilmhasadominantpeakat(002).ScanningelectronmicroscopyobservationshowedacolumnargrainstructureoftheZnOfilmtothesubstrate.ThebilayerdeviceofAl2O3/ZnOfilmshadstableresistiveswitchingbehaviorswithagoodenduranceperformanceofmorethan200cycles,highresistiveswitchingratioofover103atareadvoltageof0.1V,whichisbetterthanthatofthesingleoxidelayerdeviceofZnOfilm.Apossibleresistiveswitchingfilamentarymodewasdemonstratedinthispaper.TheconductionmechanismsofhighandlowresistancestatescanbeexplainedbyspacechargelimitedconductionandOhmic’sbehaviors.Theenduranceofthebilayer(BL)devicewasnotdegradeduponbendingcycles,whichindicatesthepotentialoftheflexibleresistiveswitchingrandomaccessmemoryapplications.