简介:Inthispaper,thevariablecoefficientSine-Gordontypeequationuxt=a(t)sinu+β(t)uxx+k(t)(xux)xisdiscussed.ItisrelatedtotheeigenvalueproblemVx=QV.Thestructureequationandtheevolutionlawsofscatteringdataforthesecondequationarederivedandtheinversescatteringsolutionofthefirstequationisobtained.
简介:在求块Toeplitz矩阵束(Amn,Bmn)特征值的Lanczos过程中,通过对移位块Toepltz矩阵Amn-ρBmn进行基于sine变换的块预处理,从而改进了位移块Toeplitz矩阵的谱分布,加速了Lanczos过程的收敛速度.该块预处理方法能通过快速算法有效快速执行.本文证明了预处理后Lanczos过程收敛迅速,并通过实验证明该算法求解大规模矩阵问题尤其有效.
简介:Intheprocessofdevelopingandadjustingtheproductinthisproject,weneedsomesignalsources,whichusuallyaffordsquareorsinewave.Generallythesquarewareisusedfordigitlogic,butfortheanalogsignalwaveisusedtojudgethelinearity'squalitiesandotherfunctionsoftheelectriccircuit.Howeverthecommonready-madesignalsourceisallunidirectionalsinewave,thesignalsourceswhosephaseshiftcanarbitrarilyberegulatedandwhichhaveprecisephasearestillnotavailableonethecurrentmarket.
简介:AsolutiontothereparametrizationofBéziercurvesbysinetransformationofBernsteinbasisispresented.Theneweffectivereparametrizationmethodisgiventhroughthefollowingprocedures:educingSineBernstein-BézierClass-SBBCfunction,definingSBBCcurveanddiscussingtherelationbetweenSBBCandBéziercurve.
简介:本文利用齐次平衡原则及最近发展起来的F-展开法求出了Sine-Gordon方程的一些精确解.
简介:Thepatterns(inflowplan)ofroughturbulentsteadyflowsinmeanderingstreamsareinvestigatedexperimentally.Theflowcrosssectionisrectangular,theflowwidthisconstant,thechannelbedisflat;theplanshapeissinegenerated.Incontrasttopreviousworks,wherethecomputedflowpatternswereofthesamecharacter,irrespectiveofthesinuosityofthechannel,itisfound,onthebasisofpresentexperiments,thateverydifferentplangeometryofameanderingflowhasitsownflowpicture.Inthecaseof“small"sinuositychannels,theflowconvectivelyacceleratesattheinnerbankbet?
简介:Inthispaper,afastalgorithmforthediscretesinetransform(DST)ofaToeplitzmatrixoforderNisderived.OnlyO(NlogN)+O(M)timeisneededforthecomputationofMelements.TheauxiliarystoragerequirementisO(N).Anapplicationofthenewfastalgorithmisalsodiscussed.
简介:Inthispaper,weareconcernedwiththenumericalsolutionofsecond-orderpartialdifferentialequations.WeanalysetheuseoftheSineTransformprecondilionersforthesolutionoflinearsystemsarisingfromthediscretizationofp.d.e.viathepreconditionedconjugategradientmethod.Forthesecond-orderpartialdifferentialequationswithDirichlelboundaryconditions,weprovethattheconditionnumberofthepreconditionedsystemisO(1)whiletheconditionnumberoftheoriginalsystemisO(m2)Heremisthenumberofinteriorgridpointsineachdirection.Suchconditionnumberproducesalinearconvergencerale.
简介:Throughamappingrelationbetweenthetriplesine-GordonandФ5model,wediscusstheequationindetail.Aseriesofsolitarywavesolutionsforthetriplesine-GordonequationisobtainedbytheexistingonesoftheФ5model.Somedetailedsolitarywavesolutionsaregivenforsomespecialcoefficientswhichhavesignificanceinphysics.
简介:Inthispaper,westudyanoperatorswhichmapseveryn-by-nsymmetricmatrixA,toamatrixs(A_n)thatminimizes||B_n-A_n||FoverthesetofallmatricesB_n,thatcanbediagonalizedbythesinetransform.Thematrixs(A_n),calledtheoptimalsinetransformpreconditioner,isdefinedforanyn-by-nsymmetricmatricesA_n.Thecostofconstructings(A_n)isthesameasthatofoptimalcirculantpreconditionerc(A_n)whichisdefinedin[8],Thes(A_n)hasbeenprovedin[6]tobeagoodpreconditionerinsolvingsymmetricToeplitzsystemswiththepreconditionedconjugategradient(PCG)method.Inthispaper,wediscussthealgebraicandgeometricpropertiesoftheoperators,andcomputeitsoperatornormsinBanachspacesofsymmetricmatrices.Somenumericaltestsandanapplicationinimagerestorationarealsogiven.
简介:Basedonsineandcosinefunctions,thecompactlysupportedorthogonalwaveletfiltercoefficientswitharbitrarylengthareconstructedforthefirsttime.When/N=2k-1andN=2k,theunifiedanalyticconstructionsoforthogonalwaveletfiltersareputforward,respectively.ThefamousDaubechiesfilterandsomeotherwell-knownwaveletfiltersaretestedbytheproposednovelmethodwhichisveryusefulforwavelettheoryresearchandmanyapplicationareassuchaspatternrecognition.