简介:Inanormalousdispersionofmonomodeopticalfiber,opticalsolitonsareevolvedfromopticalpulseswhenthedispersionisbalancedbythenonlinearity.Undistortedtransmissioncanberealizedbyusingopticalsolitons,whichcanoffermuchgreaterthetransmissioncapacityandextendtherepeaterspacingofthefibercommunicationsystem.Themechanismofthegenerationofopticalsolitonsisexpounded.Afewformsofnonlineartransmissionequationareobtainedbyusingaconcisemethod.Thegeneralcompleteexpressionofelementarysolitonsolutionofthenonlineartransmissionequationwithoutlossisgiven,andthedesignofthesolitontransmissionsystemisdiscussed.
简介:Onthebasisofthetechniquesofsingularvaluedecompositionandgeneralizedinverse,twonewmethodsfordesigningassociativememoriesarepresented.Thetwomethodsnotonlyguaranteethateachgivenvectorisanequilibriumpointofthenetwork,butalsoguaranteetheasymptoticstabilityoftheequilibriumpoints.Examplesshowtheeffectivenessofthenewmethods.
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简介:Recentprogressesmadebyauthorsonmonochromaticandtunableterahertz(THz)generationbasedonnonlinearopticsarereviewed,includingTHzparametricoscillation(TPO)anddifferencefrequencygeneration(DFG).Fromthetechnicalpointofview,wedevelopextra-andintra-cavitysurface-emittedTPO,aswellasDFGwithQPM-GaAscrystal.Fromthepointofviewofmechanism,Cherenkovphase-matchingiscomprehensivelyinvestigatedinbothbulkcrystalandplanarwaveguide.AnovelschemeforcascadingenhancedCherenkovDFGinwaveguideisproposed.Fromthepointofviewofmaterial,organiccrystal4-N,N-dimethylamino-4’-N’-methyl-stibazoliumtosylate(DAST)isutilizedasthenonlinearmedium.
简介:Theoptimizationproblemisconsideredinwhichtheobjectivefunctionispseudolinear(bothpseudoconvexandpseudoconcave)andtheconstraintsarelinear.Thegeneralexpressionfortheoptimalsolutionstotheproblemisderivedwiththerepresentationtheoremofpolyhedralsets,andtheuniquenessconditionoftheoptimalsolutionandthecomputationalprocedurestodeterminealloptimalsolutions(iftheuniquenessconditionisnotsatisfied)areprovided.Finally,anillustrativeexampleisalsogiven.
简介:Thispaperisconcernedwiththeglobalboundednessproblemforaclassofstochasticnonlinearsystemswithmatchedconditions.Theuncertaintiesinthesystemsareduetoparametervariationsandexternalstochasticdisturbance.Onlythematchedconditionsandthepossibleboundoftheuncertaintiesaredemanded.BasedonthestochasticLyapunovstabilitytheory,anexplicitcontrollerisconstructedinthegradientdirection,whichrendersresponsesoftheclosed-loopsystemsbegloballyboundedinprobability.Whenthesystemsdegradetolinearsystems,thecontrollerbecomeslinear.Illustrativeexamplesaregiventoshowtheeffectivenessoftheproposedmethod.
简介:TheexponentialpassivefilteringproblemforaclassofnonlinearMarkovjumpsystemswithuncertaintiesandtime-delaysisstudied.Theuncertainparametersareassumedunknownbutnormbounded,andthenonlinearitiessatisfythequadraticcondition.Basedonthepassivefilteringtheory,thesufficientconditionfortheexistenceofthemode-dependentpassivefilterisgivenbyanalyzingthereconstructedobserversystem.ByusingtheappropriateLyapunov-Krasovskiifunctionandapplyinglinearmatrixinequalities,thedesignschemeofthepassivefilterisderivedanddescribedasanoptimizationone.Thepresentedexponentialpassivefiltermakestheerrordynamicsystemsexponentiallystochasticallystableforalltheadmissibleuncertainties,time-delaysandnonlinearities,hasthebetterabilitiesofstatetrackingandsatisfiesthegivenpassivenormindex.Simulationresultsdemonstratethevalidityoftheproposedapproach.
简介:Forthecalculationofnon-linearmagneticfields,asimpleprogramcanbeaseffectiveasalargecommercializedsoftwarepackage.Ifrelaxationmethodsareused,theymustincludesuccessiveover-relaxationandunder-relaxationandmuchattentionmustbepaidtotherelaxationfactorandtheinterpolation.Inthispapersomeskillsareproposedonthesettingofaninterpolationswitchandthechoosingofsaturationpointsoastoassuresatisfiedconvergenceproperties.Thenumericalresultsbyusingthesemethodsconformwelltothetests.
简介:Previously,anovelclassifiercalledKernel-basedNonlinearDiscriminator(KND)wasproposedtodiscriminateapatternclassfromotherclassesbyminimizingmeaneffectofthelatter.Toconsidertheeffectofthetargetclass,thispaperintroducesanobliqueprojectionalgorithmtodeterminethecoefficientsofaKNDsothatitisextendedtoanewversioncalledextendedKND(eKND).IneKNDconstruction,thedesiredoutputvectorofthetargetclassisobliquelyprojectedontotherelevantsubspacealongthesubspacerelatedtootherclasses.Inaddition,asimpletechniqueisproposedtocalculatetheassociatedobliqueprojectionoperator.ExperimentalresultsonhandwrittendigitrecognitionshowthatthealgorithmperformesbetterthanaKNDclassifierandsomeothercommonlyusedclassifiers.
简介:Sequentialmeasurementprocessingisofbenefittobothestimationaccuracyandcomputationalefficiency.Whenthenoisesarecorrelatedacrossthemeasurementcomponents,decorrelationbasedoncovariancematrixfactorizationisrequiredinthepreviousmethodsinordertoperformsequentialupdatesproperly.Anewsequentialprocessingmethod,whichcarriesoutthesequentialupdatesdirectlyusingthecorrelatedmeasurementcomponents,isproposed.Andatypicalsequentialprocessingexampleisinvestigated,wheretheconvertedpositionmeasurementsareusedtoestimatetargetstatesbystandardKalmanfilteringequationsandtheconvertedDopplermeasurementsarethenincorporatedintoaminimummeansquarederror(MMSE)estimatorwiththeupdatedcross-covarianceinvolvedtoaccountforthecorrelatederrors.Numericalsimulationsdemonstratethesuperiorityoftheproposednewsequentialprocessingintermsofbetteraccuracyandconsistencythantheconventionalsequentialfilterbasedonmeasurementdecorrelation.
简介:Twocomplexproperties,varyingtime-delayandblock-orientednonlinearity,areverycommoninchemicalengineeringprocessesandnoteasytobecontrolledbyroutinecontrolmethods.Aimedatthesetwocomplexproperties,anoveladaptivecontrolalgorithmthebasisofnonlinearOFS(orthonormalfunctionalseries)modelisproposed.First,thehybridmodelwhichcombinesOFSandVolterraseriesisintroduced.Then,astablestatefeedbackstrategyisusedtoconstructanonlinearadaptivecontrolalgorithmthatcanguaranteetheclosed-loopstabilityandcantrackthesetpointcurvewithoutsteady-stateerrors.Finally,controlsimulationsandexperimentsonanonlinearprocesswithvaryingtime-delayarepresented.Anumberofexperimentalresultsvalidatetheefficiencyandsuperiorityofthisalgorithm.
简介:Inthispaper,animprovedmethod,whichisbasedontheharmonic-balancetech-nique,forspeedinguptheconvergenceiterationprocedureispresented.Asanexample,itisappliedtothenonlinearanalysisofmicrowavemixer,inwhichasimpletimedomaintofre-quencydomaintransformationtechniqueforthemixerdiodeisfirstlyintroduced.Theuseofthistechniquesavescomputingtimedramatically.Andtheanalyzedresultsareingoodagreementwiththeresultspublished.TheimprovedmethodcanalsobeextendedtotheCAAofnonlinearcircuitswithmulti-devices.
简介:Forthelargenumberofnonlineardegradationdevicesexistinginaproject,theexistingmethodshavenotsystematicallystudiedtheeffectsofrandomeffectontheremaininglifetime(RL),theaccuracyandefficiencyoftheparametersestimationarenothigh,andthecurrentdegradationstateofthetargetdeviceisnotaccuratelyestimated.Inthispaper,anonlinearWienerdegradationmodelwithrandomeffectisproposedandthecorrespondingprobabilitydensityfunction(PDF)ofthefirsthittingtime(FHT)isdeduced.Aparameterestimationmethodbasedonmodifiedexpectationmaximum(EM)algorithmisproposedtoobtaintheestimatedvalueoffixedcoefficientandthepriorivalueofrandomcoefficientinthemodel.Theposteriorvalueoftherandomcoefficientandthecurrentdegradationstateoftargetdeviceareupdatedsynchronouslybythestatespacemodel(SSM)andtheKalmanfilteralgorithm.ThePDFofRLwithrandomeffectisdeduced.AsimulationexampleisanalyzedtoverifythattheproposedmethodhastheobviousadvantageovertheexistingmethodsinparameterestimationerrorandRLpredictionaccuracy.
简介:Asemi-analyticalmethodintimedomainispresentedforanalysisofthetransientresponseofnonuniformtransmissionlines.Inthismethod,thetelegraphequationsintimedomainisdifferencedinspacedomainfirst,andistransformedintoasetoffirst-orderdifferentialequationsofvoltageandcurrentwithrespecttotime.Byintegratingthesedifferentialequationswithrespecttotime,andprecisecomputation,thesolutionofthesedifferentialequationscanbeobtained.Thismethodcansolvethetransientresponseofvariouskindsoftransmissionlineswitharbitraryterminalnetworks.Particularly,itcananalyzethenonuniformlineswithinitialconditions,forwhichthereisnoexistingeffectivemethodtoanalyzethetimeresponsesofar.Theresultsobtainedwiththismethodarestableandaccurate.Twoexamplesaregiventoillustratetheapplicationofthismethod.
简介:Thedispersion-managedsoliton(DMS)transmissionmodelofdispersion-managedsystemsisestablished,andtheintrachannelDMSinteractionsequationisobtained.TheimpactofsolitoninteractionsonDMSsystemsarenumericallyinvestigated.Finally,therelationshipsofthecollisionlengthchangingwithmapstrengtharerevealed.