简介:Inthispaper,alargeclassofndimensionalorthogonalandbiorthognalwaveletfilters(lowpassandhighpass)arepresentedinexplicitexpression.Wealsocharacterizeorthogonalfilterswithlinearphaseinthiscase.Someexamplesarealsogiven,includingnonseparableorhogonalandbiorthogonalfilterswithlinearphase.
简介:Anecessaryandsufficientconditionofregularityof(0,1,…,m-2,m)interpo-lationonthezerosoftheLaguerrepolynomialsLn(α)(x)(α≥-1)inamanageableformisestablished.Meanwhile,theexplicitrepresentationofthefundamentalpolynomials,whentheyexist,isgiven.Moreover,itisshownthat,iftheproblemof(0,1,…,m-2,TO)interpolationhasaninfinityofsolutions,thenthegeneralformofthesolutionsisf0(x)+Cf1(x)withanarbitraryconstantC.
简介:AfiniteelementmethodforthesolutionofOseenequationinexteriordomainisproposed.Inthismethod,acircularartificialboundaryisintroducedtomakethecomputationaldomainfinite.Then,theexactrelationbetweenthenormalstressandtheprescribedvelocityfieldontheartificialboundarycanbeobtainedanalytically.Thisrelationcanserveasanboundaryconditionfortheboundaryvalueproblemdefinedonthefinitedomainboundedbytheartificialboundary.Numericalexperimentispresentedtodemonstratetheperformanceofthemethod.
简介:Inthispaper,weinvestigatethecouplingofnaturalboundaryelementandfiniteelementmethodsofexteriorinitialboundaryvalueproblemsforhyperbolicequations.Thegoverningequationisfirstdiscretizedintime,leadingtoatime-stepscheme,whereanexteriorellipticproblemhastobesolvedineachtimestep.Second,acircularartificialboundaryFRconsistingofacircleofradiusRisintroduced,theoriginalprobleminanunboundeddomainistransformedintothenonlocalboundaryvalueprobleminaboundedsubdomain.AndthenaturalintegralequationandthePoissonintegralformulaareobtainedintheinfinitedomainΩ2outsidecircleofradiusR.Thecoupledvariationalformulationisgiven.Onlythefunctionitself,notitsnormalderivativeatartificialboundaryΓR,appearsinthevariationalequation,sothattheunknownnumbersarereducedandtheboundaryelementstiffnessmatrixhasafewdifferentelements.Suchacoupledmethodissuperiortotheonebasedondirectboundaryelementmethod.Thispaperdiscussesfiniteelementdiscretizationforvariationalproblemanditscorrespondingnumericaltechnique,andtheconvergenceforthenumericalsolutions.Finally,thenumericalexampleispresentedtoillustratefeasibilityandefficiencyofthismethod.
简介:1.IntroductionTheaimofthisnoteistoestablishtheconvergenceofthenonconformingfiniteelementmethodsforthesecondorderellipticproblemwiththelowestregularity.Theproofoftheconvergenceisnottrivial,althoughtheconvergenceresultsfortheconformingfiniteelementmeth...
简介:与阻抗类型边界在2由一个裂缝散布问题的波浪被考虑。这个问题由薄两方面的圆柱的屏幕为波浪的衍射建模。为解决这个问题的一个数字方法被开发。这个问题的答案在联合尖潜力和单个层的潜力形式被代表。密度功能满足的线性不可分的方程为一般parameterized弧被导出。弱单个的积分和Cauchy在这些方程的单个不可分的产生与截断错误分析用一个高度精确的计划被计算。计划的优点在这份报纸建议在一只手里,我们不需要裂缝的analyticity性质,我们允许不同建筑群的事实被珍视在裂缝的双方的表面阻抗。在另外的手里,我们避免超积分。显示出计划的有效性的数字实现被介绍。[从作者抽象]