简介：Theoperationprincipleofanarrayedwaveguidegrating(AWG)multiplexerisintroducedandthe4×4AWGwithfollowingdesignparametersisdiscussedindetail,suchasthechoiceofwavelength,theneighboringarrayedwaveguidedistanceΔL,thechannelfrequencyintervalΔf,andthefreespectralrange.Thestructureof4×4AWGisdesignedandtheresultofstimulatedtestisalsogiven.Analysisshowsthatthe4×4AWGischaracterizedbyawidedynamicrange,lowcrosstalk,betterspectrumproperties,andacompactstructure.

简介：在这个字母，对THz设备适用的一种二维的photonic水晶结构被设计，并且怎么在这结构形成microcavity被讨论。反响的洞的主要性质被分析，在哪个飞机波浪扩大方法被用来做计算和模拟。我们鈥檝e由改变参数在THz区域学习了bandgap结构和反响的频率的变化例如格子常数，绝缘的经常的对比和充满的因素。研究结果为生产THz设备和THz系统的申请提供了理论支持。

简介：Aflat-topinterleaver,inwhichamirrorononearmoftheMichelsoninterferomeferisreplacedbyaG-Tresonator,isproposed.Intheinterleaver,theparametersincludingthechannelspacingof50GHz,ripplelessthan0.05dB,-0.5dBpassbandof43GHz(86%ofthespacing),-30dBstopbandof42GHz(84%ofthespacing),andachannelisolationhigherthan40dB,areachieved.

简介：Wavelet-fractalbasedSAR(syntheticapertureradar)imageprocessingisoneoftheadvancedtechnologiesinimageprocessing.Themainconceptofanalysisisthatafterwavelettransformation,multifractalspectrumofthesignalisdifferentfromthatofnoise.ThisdifferenceisusedtoalleviatethenoiseproducedbySARimage.ThemethodtodenoiseSARimageusingtheprocessbasedonwavelet-fractalanalysisisdiscussedindetail.Essentially,thepresentmethodfocusesonadjustingtheHlderexponentαofmultifractalspectrum.Aftersimulation,αshouldbeadjustedto1.72-1.73.Themorethevalueofαexceeds1.73,thelessdistinctivetheedgesofSARimagebecome.Accordingtotheauthorsdenoisingisoptimalatα=1.72-1.73.Inotherwords,whenα=1.72-1.73,asmoothanddenoisedSARimageisproduced.

简介：Asemi-analyticalmethodintimedomainispresentedforanalysisofthetransientresponseofnonuniformtransmissionlines.Inthismethod,thetelegraphequationsintimedomainisdifferencedinspacedomainfirst,andistransformedintoasetoffirst-orderdifferentialequationsofvoltageandcurrentwithrespecttotime.Byintegratingthesedifferentialequationswithrespecttotime,andprecisecomputation,thesolutionofthesedifferentialequationscanbeobtained.Thismethodcansolvethetransientresponseofvariouskindsoftransmissionlineswitharbitraryterminalnetworks.Particularly,itcananalyzethenonuniformlineswithinitialconditions,forwhichthereisnoexistingeffectivemethodtoanalyzethetimeresponsesofar.Theresultsobtainedwiththismethodarestableandaccurate.Twoexamplesaregiventoillustratetheapplicationofthismethod.

简介：Thecalculationmethodaboutinfraredmulti-sitespassivesystemlocationisintroducedbasedontheprincipleoftheweightedleastsquaremethod,andthevariancematrixofestimatederrorisoffered.Throughdeduction,itcanbefoundoutthattreatedappraiseprecisioncanbedirectlyanalyzedanddeducedwithoutcarryingoutrealmeasureandreachingestimationvalue.Thesimulationresultshowsthatthesystemperformancebasedontheweightedleastsquaremethodismuchbetterthanthetraditionalpassivelocationmethod,anditcanbealsousedforreferencetotheresearchofthelocationalgorithmofsimilarsystem.

简介：Anoveltextindependentspeakeridentificationsystemisproposed.Intheproposedsystem,the12-orderperceptuallinearpredictivecepstrumandtheirdeltacoefficientsinthespanoffiveframesareextractedfromthesegmentedspeechbasedonthemethodofpitchsynchronousanalysis.TheFisherratiosoftheoriginalcoefficientsthenbecalculated,andthecoefficientswhoseFisherratiosarebiggerareselectedtoformthe13-dimensionalfeaturevectorsofspeaker.TheGaussianmixturemodelisusedtomodelthespeakers.TheexperimentalresultsshowthattheidentificationaccuracyoftheproposedsystemisobviouslybetterthanthatofthesystemsbasedonotherconventionalcoefficientslikethelinearpredictivecepstralcoefficientsandtheMel-frequencycepstralcoefficients.

简介：Thedesignandperformanceanalysisofnetworkedcontrolsystemswithrandomnetworkdelayintheforwardchannelisproposed,whicharedescribedinastate-spaceform.Anewcontrolschemeisusedtoovercometheeffectsofnetworktransmissiondelay,whichistermednetworkedpredictivecontrol(NPC).Furthermore,threedifferentwaystochoosecontrolinputarediscussedandtheperformancesareanalyzed,respectively.Bothreal-timesimulationsandpracticalexperimentsshowtheeffectivenessofthecontrolscheme.

简介：Withthevigorousexpansionofnonlinearadaptivefilteringwithreal-valuedkernelfunctions,itscounterpartcomplexkerneladaptivefilteringalgorithmswerealsosequentiallyproposedtosolvethecomplex-valuednonlinearproblemsarisinginalmostallreal-worldapplications.ThispaperfirstlypresentstwoschemesofthecomplexGaussiankernel-basedadaptivefilteringalgorithmstoillustratetheirrespectivecharacteristics.ThenthetheoreticalconvergencebehaviorofthecomplexGaussiankernelleastmeansquare(LMS)algorithmisstudiedbyusingthefixeddictionarystrategy.ThesimulationresultsdemonstratethatthetheoreticalcurvespredictedbythederivedanalyticalmodelsconsistentlycoincidewiththeMonteCarlosimulationresultsinbothtransientandsteady-statestagesfortwointroducedcomplexGaussiankernelLMSalgonthmsusingnon-circularcomplexdata.Theanalyticalmodelsareabletoberegardasatheoreticaltoolevaluatingabilityandallowtocomparewithmeansquareerror(MSE)performanceamongofcomplexkernelLMS(KLMS)methodsaccordingtothespecifiedkernelbandwidthandthelengthofdictionary.

简介：Withamultiplicativespecklemodel,thispapershowsthemulti-lookpolarimetricsyntheticapertureradar(SAR)dataobeysageneralizedK-distribution.Tovalidatethisdistributionmodel,themulti-lookintensityK-distributionisparticularlytested.Therelationshipbetweentheheterogeneitycoefficientofthesceneandtheproperstatisticalmodelisexperimentallyestablished.Inaddition,basedontheresultsofthestatisticalanalysis,anadaptiveclassificationschemeispresented,andtheimprovedclassificationshowstheimportanceofthestatisticalanalysis.

简介：Ageneralversionoftheinvertedexponentialdistributionisintroduced,studiedandanalyzed.ThisgeneralizationdependsonthemethodofMarshall-Olkintoextendafamilyofdistributions.Somestatisticalandreliabilitypropertiesofthisfamilyarestudied.Inaddition,numericalestimationofthemaximumlikelihoodestimate(MLE)parametersarediscussedindetails.Asanapplication,somerealdatasetsareanalyzedanditisobservedthatthepresentedfamilyprovidesabetterfitthansomeotherknowndistributions.

简介：Inpracticalapplications,weoftenhavetodealwithhigh-orderdata,forexample,agrayscaleimageandavideoclipareintrinsicallya2nd-ordertensoranda3rd-ordertensor,respectively.Inordertosatistythesehigh-orderdata,itisconventionaltovectorizethesedatainadvance,whichoftendestroystheintrinsicstructuresofthedataandincludesthecurseofdimensionality.Forthisreason,weconsidertheproblemofhigh-orderdatarepresentationandclassification,andproposeatensorbasedfisherdiscriminantanalysis(FDA),whichisageneralizedversionofFDA,namedasGFDA.ExperimentalresultsshowourGFDAoutperformstheexistingmethods,suchasthe2-directional2-dimensionalprincipalcomponentanalysis((2D)2PCA),2-directional2-dimensionallineardiscriminantanalysis((2D)2LDA),andmultilineardiscriminantanalysis(MDA),inhigh-orderdataclassificationunderalowercompressionratio.

简介：Theattempttorepresentasignalsimultaneouslyintimeandfrequencydomainsisfullofchallenges.TherecentlyproposedadaptiveFourierdecomposition(AFD)offersapracticalapproachtosolvethisproblem.ThispaperpresentstheprinciplesoftheAFDbasedtime-frequencyanalysisinthreeaspects:instantaneousfrequencyanalysis,frequencyspectrumanalysis,andthespectrogramanalysis.AnexperimentisconductedandcomparedwiththeFouriertransforminconvergencerateandshort-timeFouriertransformintime-frequencydistribution.TheproposedapproachperformsbetterthanboththeFouriertransformandshort-timeFouriertransform.

简介：Thereexistsagreatdealofperiodicnon-stationaryprocessesinnatural,socialandeco-nomicalphenomenon.Itisveryimportanttorealizethedynamicanalysisandreal-timeforecastwithinaperiod.Inthisletter,awavelet-Kalmanhybridestimationandforecastingalgorithmbasedonstep-by-stepfilteringwiththereal-timeandrecursionpropertyisputforward.ItcombinestheadvantagesofKalmanfilterandwavelettransform.Utilizingtheinformationprovidedbymulti-sensoreffectively,thisalgorithmcanrealizenotonlyreal-timetrackinganddynamicmulti-stepfore-castingwithinaperiod,butalsothedynamicforecastingbetweenperiods,andithasagreatvaluetothesystemdecision-making.Simulationresultsshowthatthisalgorithmisvaluable.

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.

简介：Todealwiththenon-Gaussiannoiseinstandard2-DSARimages,thederampedsignalinimagingplane,andthepossiblesymmetricdistributionofcomplexnoise,thefourth-ordercumulantofcomplexprocessisintroducedintoSARtomography.WiththeestimatedARparametersofARMAmodelofnoisethroughYule-Walkerequation,thesignalseriesofheightispre-filtered.Then,throughESPRIT,thespectrumisobtainedandtheapertureinheightdirectionissynthesized.Finally,theSARtomographyimagingofsceneisachieved.Theresultsofprocessingonsignalwithnon-Gaussiannoisedemonstratetherobustnessoftheproposedmethod.Thetomographyimagingofthescenesshowsthatthehigher-orderspectrumanalysisisfeasibleintheapplication.

简介：Bistaticforward-lookingsyntheticapertureradar(SAR)hasmanyadvantagesandapplicationsowingtoitstwodimensionalimagingcapability.Therecouldbevariousimagingconfigurationsbecauseofthegeometricflexibilityofbistaticplatforms,resultinginkindsofmodelsbuiltindependentlyamongwhichtherecouldbesomesimilareventhesamemotionfeatures.Comprehensiveresearchonsuchsystemsinamorecomprehensiveandgeneralpointofviewisrequiredtoaddresstheirdifferenceandconsistency.PropertyanalysisofbistaticforwardlookingSARwitharbitrarygeometryisachievedincludingstripmapandspotlightmodesonairborneplatform,missile-borneplatform,andhybridplatformofboth.Emphasisisplacedonazimuthspacevarianceofsomekeyparameterssignificantlyaffectingthesubsequentimagingprocessing,basedonwhichthefrequencyspectraarefurtherdescribedandcomparedconsideringrespectivefeaturesofdifferentplatformsforfrequencyimagingalgorithmdeveloping.Simulationresultsconfirmtheeffectivenessandcorrectnessofouranalysis.

简介：Thestructuralparametersoflow-steppedmirrorwhichisthecorecomponentofalightFouriertransforminfraredspectrometer(FTIRS)haveimportantinfluenceontheperformanceoftheinstrument.Asimplemethodofmultipledepositionisproposedtofabricatealow-steppedmirrorwithstepheightof625nm,foritshighprecision,highefficiencyandminiaturization.Sothefilmstresswillbeintroducedintheprocessofcoating,whichcanleadtostepdeformation.Webuildabendingmodelofthelow-steppedmirrorandanalyzetheinfluenceofitsdeformation.Thelightintensityandspectrumarechangedbythestepdeformation.Therefore,thefilmstressshouldbereducedinordertoensuretheaccuracyofthespectralinformation.Increasingthethicknessofsubstrateis.proposedinthispapertoreducethestepdeformation,besidesadjustingthecoatingtemperatureandaddingsub-layer.Ourresultsrevealthatthebasicrequirementsofthesystemaresatisfiedwhenthethicknessofthesubstrateis5mmintheappropriatecoatingenvironment.AnFTIRSbasedonsteppedmirrorsandgridbeamsplitterisassembledandcorrespondingexperimentiscarriedouttoobtainthespectrumcurveofacetonitrile.

简介：Thispaperpresentsahumanactionrecognitionmethod.Itanalyzesthespatio-temporalgridsalongthedensetrajectoriesandgeneratesthehistogramoforientedgradients(HOG)andhistogramofopticalflow(HOF)todescribetheappearanceandmotionofthehumanobject.Then,HOGcombinedwithHOFisconvertedtobag-of-words(BoWs)bythevocabularytree.Finally,itappliesrandomforesttorecognizethetypeofhumanaction.Intheexperiments,KTHdatabaseandURADLdatabasearetestedfortheperformanceevaluation.Comparingwiththeotherapproaches,weshowthatourapproachhasabetterperformancefortheactionvideoswithhighinter-classandlowinter-classvariabilities.IndexTermsBag-of-words(BoWs),densetrajectories,histogramofopticalflow(HOF),histogramoforientedgradient(HOG),randomforest,vocabularytree.

简介：PackagingofMEMS(micro-electro-mechanicalsystem)devicesposesmorechallengesthanconventionalICpackaging,sincetheperformanceoftheMEMSdevicesishighlydependentonpackagingprocesses.ALandGridArray(LGA)packageisintroducedforMEMStechnologybasedlinearmulti-axisaccelerometers.FiniteelementmodelingisconductedtosimulatethewarpagebehavioroftheLGApackages.Amethodtocorrelatethepackagewarpagetomatrixblockwarpagehasbeendeveloped.Warpageforbothpackageandsensorsubstrateareobtained.Warpagepredictedbysimulationcorrelatesverywellwithexperimentalmeasurements.Basedonthisvalidatedmethod,detaileddesignanalysiswithdifferentpackagegeometricalvariationsarecarriedouttooptimizethepackagedesign.Withtheoptimizedpackagestructure,thepackagingeffectonaccelerometersignalperformanceiswellcontrolled.