简介：Toacceleratethetrainingofsupportvectordomaindescription(SVDD),confidencesupportvectordomaindescription(CSVDD)isproposedbasedontheobservationthatthedescriptionboundaryisdeterminedbyasmallsubsetoftrainingdatacalledsupportvectors.Namely,thenumberoftrainingsamplesintheuserdefinedsphereiscalculatedandtakenastheconfidencemeasure,accordingtowhichthetrainingsamplesarerankedinascendingorder.ThoseformerrankedonesareselectedastheboundarytargetsfortheSVDDtraining.SimulationsonUCIdatademonstratetheeffectivenessandsuperiorityofCSVDD:thenumberoftrainingtargetsandthetrainingtimearereducedwithoutanylossofaccuracy.

简介：Anewblock-basedfractalimagecodingalgorithmcalledFractalBlockCodinginResidueDomain(FBCRD)isproposed.InbasicFractalBlockCoding(FBC)algorithm,eachblock(calledrangeblock)isencodedbyanaffinemappingfromadomainblockwithinthesameimagetoitself.Thedecoderusestheparametersofthesemappingstosynthesizethereconstructedimagethroughaniterativeprocedure.FBCRDisamodificationofbasicFBC.InFBCRD,rangeblocksanddomainblocksareallresidueblockssubtractedfromtheirblockmeansandboththeparametersofaffinemappingsandblockmeansarecoded.Thismodificationleadstofeweriterationsatthedecoder.AnoptimizeddecodingstrategyisalsointroducedwhichreducestotaldecodingtimebymorethanhalfofthatofbasicFBC.Thisimprovementisfavorableforrealtimeimplementationoffractalimagecompression.

简介：Anovelfinite-difference(FD)approximationinfrequency-domainfortheMurboundaryconditionispresentedinthispaper.CombinedwiththeFDequationsderivedforinhomogeneousanisotropicmedia,thisboundaryconditionisconvenientandeffectivetobeappliedtotheEMscatteringbyelectricallylargeobjectsofcomplexmedia.Boththememoryrequirementandthecomputingtimearedramaticallysaved,comparedwiththeMM,withthecompressedstoragetechnique.Forthecasesofdifferentmedia,RCSofcircularandrectangularcylindersarecomputed.Goodagreementisobtainedbetweentheresultsbythismethodandthoseavailable.

简介：Erroranalysismethodsinfrequencydomainaredevelopedinthispaperfordeterminingthecharacteristicrootandtransferfunctionerrorswhenthelinearmultipassalgorithmsareusedtosolvelineardifferentialequations.therelationbetweenthelocaltruncationerrorintimedomainandtheerrorinfrequencydomainisestablished,whichisthebasisfordevelopingtheerrorestimationmethods.TheerrorestimationmethodsforthedigitalsimulationmodelconstructedbyusingtheRunge-Kuttaalgorithmsandthelinearmultisteppredictor-correctoralgorithmsarealsogiven.

简介：Theequationoftime-domainwavepropagationindispersivemediaandtheexplicitbeampropagationmethodarepresentedinthispaper.Thismethodisdemonstratedbytheshortopticalpulsesinadirectionalcouplerwithsecondorderdispersiveeffectandshowstobeinfullagreementwithformerreferences.Thismethodissimple,easyandpractical.

简介：Theterahertztime-domainspectroscopy(THz-TDS)systemandtherelatedtechnologyandtheapplicationsinCapitalNormalUniversityarepresented.ThemostoftenusedTHz-TDSsystemasaspectroscopicmeasurementsetupinourlabisintroducedindetail,includingtheTHzradiationsource,theTHzdetectionmethodanditsmeasurement,andthecontrolsystem.THzspectraofvariousmaterialsissummarizedanddiscussed.Thesematerialsincludebutnotlimitedtotwokindsoftypicalmatter—theillegaldrugsandexplosives.Thebiologicalmacro-molecules,cosmeticsandfinechemicalmaterials,ediblepigmentsandfoodadditives,homocysteicacidandrelatedcompounds,heavyionsinsoil,Chinesemedicines,tobaccoandcrops,oilandchemicalproducts,carbonnanotubes,superconductors,andvarioussemiconductorsandtheirheterojunctions,arepresented.THzemissionsfromtheInAsandInNsemiconductorssurfacearecompared.THzspectralinvestigationofmetallicmeshstructuresissummarized.Finally,anoutlookofTHzspectroscopicapplicationsisgiven.

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简介：Inordertoachievetheinformationfusioninthetimedomainbasedontheevidencetheory,anevidencecombinationmethodinthetimedomainbasedonreliabilityandimportanceisproposedaccordingtotheideaofevidencediscount.Firstly,thedistortionofthetime-domainevidenceisjudgedbasedonsingleexponentialsmoothing.Thereal-timereliabilityoftheevidenceattheadjacenttimeisobtainedbythereal-timereliabilityassessmentmethodoftheevidencebasedonthecredibilitydecaymodel.Then,therelativeimportanceoftheevidenceattheadjacenttimeisobtainedbycomprehensivelyconsideringimprovedconflictdegreeanduncertainty.Finally,basedonthecriterionofevidencediscountandtheDempster’sruleofcombination,theevidencecombinationiscarriedouttoachievethesequentialcombinationoftime-domainevidence.Thenumericalsimulationandanalysisshowthatthismethodhasfullyembodiedthedynamiccharacteristicsoftime-domainevidencecombination,andithasstrongprocessingabilityforconflictinformationandanti-disturbingability.Theproposedmethodhasgoodapplicabilitytoinformationfusioninthetimedomain.

简介：AnapproachisproposedtorealizeadigitalchannelizedreceiverinthefractionalFourierdomain(FRFD)forsignalinterceptapplications.ThepresentedarchitecturecanbeconsideredasageneralizationofthatinthetraditionalFourierdomain.Sincethelinearfrequencymodulation(LFM)signalhasagoodenergyconcentrationintheFRFD,bychoosinganappropriatefractionalFouriertransform(FRFT)order,thepresentedarchitecturecanconcentratethebroadbandLFMsignalintoonlyonesub-channelandthatwillpreventitfromcrossingseveralsub-channels.Thustheperformanceofthesignaldetectionandparameterestimationafterthesub-channeloutputwillbeimprovedsignificantly.Thecomputationalcomplexityisreducedenormouslyduetotheimplementationofthepolyphasefilterbankdecomposition,thustheproposedarchitecturecanberealizedasefficientlyasintheFourierdomain.Therelatedsimulationresultsarepresentedtoverifythevalidityofthetheoriesandmethodsinvolvedinthispaper.

简介：Terahertz(THz)radiation,whosefrequencyrangesfrom0.1THzto10.0THz,hasrichscience,butlimitedtechnology.Ithaslongbeenconsideredthelastremainingscientificgapintheelectromagneticspectrum.Farfrombeingfullyexploited,itoffersgreatopportunitiesinscience,innovation,newtechnology,andpotentialapplications.

简介：Thetraditionalsuper-resolutiondirectionfindingmethodsbasedonsparserecoveryneedtodividetheestimationspaceintoseveraldiscreteanglegrids,whichwillbringthefinalresultsomeerror.Tothisproblem,anovelmethodforwidebandsignalsbysparserecoveryinthefrequencydomainisproposed.Theoptimizationfunctionsarefoundandsolvedbythereceiveddataateveryfrequency,onthisbasis,thesparsesupportsetisobtained,thenthedirectionofarrival(DOA)isacquiredbyintegratingtheinformationofallfrequencybins,andtheinitialsignalcanalsoberecovered.Thismethodavoidstheerrorcausedbysparserecoverymethodsbasedongriddivision,andthedegreeoffreedomisalsoexpandedbyarraytransformation,especiallyithasapreferableperformanceunderthecircumstancesofasmallnumberofsnapshotsandalowsignaltonoiseratio(SNR).

简介：Theterahertz(THz)regionoftheelectromagneticspectrum,spanningtherangebetween0.1THzand10THz,hasexperiencedarenaissanceduetotechnologicaldevelopmentsinsourcesanddetectors.Theterahertztimedomainspectroscopy(THz-TDS)systemisbyfaroneofthemostimportantmethodstogenerateanddetecttheTHzwave.Inphysics,THz-TDSisaspectroscopictechniqueinwhichthepropertiesofamaterialareprobedwithshort

简介：IntheFresneltransformdomain,aneffectiveimprovementtotheconventionaliterativealgorithmfordesigningthediffractiveopticalelements(DOEs)usedforspatialbeamshapinghasbeenproposed.ThealgorithmcansuccessfullyachievetodesignDOEsforbeamshaping.Comparedwithconventionalalgorithm,thisalgorithmcanprovidefasterconvergence,morepowerfulabilitytoovercomelocalminimumproblemandbettershapingquality.Bycomputersimulation,theresulthasshownthattheDOEsdesignedbythisalgorithmhassnchadvantagesashighuniformityatthemainlobe,lowprofileerrorandsteepedge.

简介：Thetime-domainElectroMagnetic(EM)scatteringbyburiedobjectsindispersivemediaiscalculatedwithFD-TDmethod.TheFD-TDformulainDebyedispersivemedia(boththecomplexpermeabilityandthecomplexpermittivityaredescribedbyDebyeequations)arededuced,andtheabsorbingboundaryconditionisgiven.ThevalidityofFD-TDmethodinlossymediaisverifiedthroughcomparingtheFD-TD’sresultsandtheotherones.Thepropagationoftransientpulsesindispersivemediaisstudiedindetail.Thescatteringpulsesandthewiggletracesfortypicalburiedobjectsaregiven.

简介：Movingshipsproduceasetofwavesof"V'patternontheocean.ThesewavescanoftenbeseenbySyntheticApertureRadar(SAR).Thedetectionofthesewakescanprovideimportantinformationforsurveillanceofshipping,suchasshiptravelingdirectionandspeed.AnovelapproachtothedetectionofshipwakesinSARimagesbasedonfrequencydomainisprovidedinthisletter.ComparedwithtraditionalRadon-basedapproaches,computationisreducedby20%-40%withoutlosingnearlyanyofdetectionperformance.ThetestingresultsusingrealdataandsimulationofsyntheticSARimagestestthealgorithm'sfeasibilityandrobustness.

简介：

简介：Inthiswork,wereviewthedevelopingprogressoftwo-dimensionalterahertztime-domainspectroscopy(THz-TDS)anditsdiverseapplications,includinganalyzingthepolarizationofTHzradiationfromalaser-inducedplasmasourceandstudyingthecorrespondingphysicalmechanism,andcharacterizingtheopticalpropertiesofcrystals,etc.

简介：在这份报纸，我们由电气化学的蚀刻生产多孔的硅(希腊语的第二十三个字母)，并且为重链的抗体(VHH)的重链的可变领域的察觉评估没有标签的多孔的硅生物传感器的性能是第一次。母鸡鸡蛋白人溶解酵素(HEWL)和VHH的绑定在生物传感器的思考光谱引起红移动。红移动与在从14g的范围的VHH集中成正比??踐?迱

简介：Severalindolederivativeswithdifferent‘3-'substituentshavebeeninvestigatedbyterahertz(THz)time-domainspectroscopy.Thelow-frequencyabsorptionspectraandrefractiveindiceswereobtainedintherangeof0.2THzto2.5THz(7cm–1to83cm–1).Thesederivativeswithdifferentsubstituentspresentdistinctfeatures,whichsuggeststhatTHzspectroscopyissensitivetodifferentstructuresandcomponentsofthesechemicals.Thedensityfunctionaltheorywasemployedtocalculatethelow-frequencyvibrationalpropertiesofindole-3-carboxylicacidandindole-3-propionicacidbasedontheircrystalstructures,andtheintermolecularinteractionswereinvolved.Meanwhile,thetemperaturedependenceofthespectraagreedwiththecalculatedresults.ThequantitativeanalysisofaternarymixturewasstudiedbytakingtheTHzfingerprintsintoaccount,andtheresultsdemonstrateTHzspectroscopyhasgreatpotentialforthepracticalapplicationsinbiochemistryandpharmaceutics.

简介：TheelectromagneticpropagationthroughaninhomogeneousmagnetizedplasmaslabisstudiedusingtheZ-transformformulationoftheFinite-DifferenceTime-Domain(FDTD)method.Thedirectionofelectromagneticpropagationisparalleltothebiasingmagneticfiled.TovalidatetheZ-transformalgorithm,thereflectionandtransmissioncoefficientsfortheright-handcircularlypolarizedwaveofthehomogeneousmagnetizedplasmaslabarecomputedbymeansofdiscreteFouriertransform.ThecomparisonbetweenthereflectionandtransmissioncoefficientsofthehomogeneousplasmaslabandanalyticalvaluesindicatesthatZ-transformalgorithmisveryaccurate.Whentheplasmafrequencyvariesaccordingtothesquarerootandparabolicrelations,thereflectionandtransmissioncoefficientsoftheinhomogeneousmagnetizedplasmaslabarecomputed.