简介:Heattransportatthemicroscaleisofvitalimportanceinmicrotechnologyapplications.Theheattransportequationisdifferentfromthetraditionalheattransportequationsinceasecondorderderivativeoftemperaturewithrespecttotimeandathird-ordermixedderivativeoftemperaturewithrespecttospaceandtimeareintroduced.Inthisstudy,wedevelopahybridfiniteelement-finitedifference(FE-FD)schemewithtwolevelsintimeforthethreedimensionalheattransportequationinacylindricalthinfilmwithsubmicroscalethickness.Itisshownthattheschemeisunconditionallystable.Theschemeisthenemployedtoobtainthetemperatureriseinasub-microscalecylindricalgoldfilm.Themethodcanbeappliedtoobtainthetemperatureriseinanythinfilmswithsub-microscalethickness,wherethegeometryintheplanardirectionisarbitrary.
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:或者方向性含蓄(ADI)计划通常在3D深度移植被使用。它切开3D沿着英文报纸之单行标题和嵌入的方向的方形根的操作员或者。在这糊,基于数据线,四方法的切开计划和他们的切开的错误为的理想有限差别(FD)方法和混合方法被调查。四方法的切开的计划的wavefieldextrapolation在一根数据线上被完成并且无条件地是稳定的。切开错误的数字分析证明双向FD迁居有可见数字各向异性的错误,和移植更不有的那四方法的FD比双向FD移植切开错误。为混合方法,在双向计划和四方法的计划之间的数字各向异性的错误的差别在更低的侧面的速度变化的情况中是小的。在这篇论文介绍的计划能在栈以后的3D或prestack深度移植被使用。3D深度移植的二数字计算被完成。一个人是四方法的FDand混合3D为推动回答的栈以后的深度移植,哪个各向异性的错误能在经常、可变的速度变化的情况中有效地被消除的表演。Theother是为有切开计划的two-wayhybrid的SEG/EAEG基准模型的3D射击侧面prestack深度迁居,它介绍好成像结果。基于射击数字传递接口(MPI)计划的消息被采用。
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]