学科分类
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119 个结果
  • 简介:Wediscusstheincompletesemi-iterativemethod(ISIM)foranapproximatesolutionofalinearfixedpointequationsx=Tx+cwithaboundedlinearoperatorTactingonacomplexBanachspaceXsuchthatitsresolventhasapoleoforderkatthepoint1.SufficientconditionsfortheconvergenceofISIMtoasolutionofx=Tx+c,wherecbelongstotherangespaceof(I-T)k,areestablished.WeshowthattheISIMhasanattractivefeaturethatitisusuallyconvergentevenwhenthespectralradiusoftheoperatorTisgreaterthan1andInd1T≥1.ApplicationsinfiniteMarkovchainisconsideredandillustrativeexamplesarereported,showingtheconvergencerateoftheISIMisveryhigh.

  • 标签: SINGULAR linear operator equation index DRAZIN
  • 简介:Thepurposeofthepaperistoestablishatheoryoftheconstantheatfluxratioacrossthefrozenlayerbasedonthedimensionalanalysisofthesystemequationsdescribingthefreezingprocesses.Ananalyticalmodelisthendeveloped,utilizingthistheory,forsolvingtheplanar,cylindricalandsphericalfreezingproblemswithbothinwardandoutwardfreezing.Asthereisnoexactsolutionavailableforthecylindricalandsphericalfreezingprocesses,thetemperaturedistributionintheplanarsolidificationobtainedfromthemodeliscomparedwiththeexactsolution.Theyareinexcellentagreement.Forthecylindricalandsphericalfreezing,thecompleteinwardsolidificationtimescalculatedbythemodelarecomparedwiththoseobtainedfromreferences.Theresultsareingoodagreement.Thegreatadvantageoftheproposedmodelisitssimplicityandissufficientlyaccurateformostpracticalapplications

  • 标签: analytical PLANAR CYLINDRICAL SPHERICAL solidification theory
  • 简介:在这篇论文,为解决单个延期的二拍子的圆舞连续性Runge-Kutta(TSCRK)方法的一个班微分方程(DDE)被介绍。方法被给的这的数字稳定性的分析。我们考虑二个不同盒子:(ⅰ)τ≥h,(ⅱ)τ

  • 标签: 时滞微分函数 稳定性 连续性 RUNGE-KUTTA方法
  • 简介:一个数字算法为包含与排干和涂层流动联系的第三顺序的平常的微分方程的某些边界价值问题的答案的近似被开发。数字算法获得的近似解决方案用nonpolynomialquintic花键函数发展了由的作者表演比另外的花键和域分解方法生产的那些好。算法在与排干和涂层流动表明途径的实际实用性联系的二个问题上被测试。

  • 标签: 多项式样条 数值算法 三阶边值问题 涂料 排水 三阶常微分方程
  • 简介:TheconfigurationmanagementtoolCMThasbeenusedsinceseveralyearsnow,andinquitsdifferentprojects(Virgo,GLAST,LHCb,Auger,Atlas,etc).Thefeaturesofthetoolhavecontinuouslyevolvedaccordingtothegrowingneedsofthedevelopersandtofollowtheincreasingcomplexityofthesoftwarebasesithastoservice,Howevertheoriginalconcepts:readability,simplicity,flexibility,completenesshavebeenpreservedandthesyntanofthecoreelementofthesystem-therequirementsfile-hasbeenalwaysketpbackwardcompatible.MoreandmoreprojectspecificconventionsandneedshavefounrtheirexpressionusingCMT,andsimultaneouslythefocuesetoCMTfeatureshaveevolvedaccordingly,progressivelyraisingimportancetowardslanguagecustomisation,newdocumentgeneratorsproductionofpatterns,packageorganizationandsoftwaredistribution.ThebasicpropertiesoftheCMTtoolkitwillbeshortlypresentedbutthefocusofthediscussionwillbesettotheCMTtoolkitwillbeshortlypresentedbutthefocusofthediscussionwillbesettoptheserecentevolutions,throughtsometypicalexamplesobtainedfromactualprojectsshowingspecificdefinitionsorconventions.Thediscussionisthenextendedtowardsthegeneralizedquestionofthescalabilityinsoftwareproductionandmanagementinthecontextofe.g.Gridtechnologies.TheimpactofusinggenericandhighleveltoolssuchasCMT,whichalreadyoffersseveralsolutions,RPMortheGridtechnologies,inthisrespectwillbepresented.Inparticular,theroleofformalspecificationsforthesoftwareconfigurationappearstobecriticalforquerymechanismsrequiredinmanagementoperationsorinremoteactions.

  • 标签: 软件开发 大项目用软件 软件管理
  • 简介:Aself-adaptiveprecisealgorithminthetimedomainwasemployedtosolve2-Dnonlinearcoupledheatandmoisturetransferproblems.Byexpandingvariablesatadiscretizedtimeinterval,thevariationsofvariablescanbedescribedmoreprecisely,andanonlinearcoupledinitialandboundaryvalueproblemwasconvertedintoaseriesofrecurrentlinearboundaryvalueproblemswhicharesolvedbyFEtechnique.Inthecomputation,noadditionalassumptionandthenonlineariterationarerequired,andacriterionforself-adaptivecomputationisproposedtomaintainsufficientcomputingaccuracyforthechangesizesoftimesteps.Inthenumericalcomparison,thevariationsofmaterialpropertieswithtemperature,moisturecontent,andbothtemperatureandmoisturecontentaretakenintoaccount,respectively.Satisfactoryresultshavebeenobtained,indicatingthattheproposedapproachiscapableofdealingwithcomplexnonlinearproblems.

  • 标签: 有限元分析 非线性传输 自适应系统 热量转移 离散特性
  • 简介:Basedontheextendedhomogeneouscapacityhighprecisionintegrationmethodandthespectrummethodofvirtualboundarywithacomplexradiusvector,anovelsemi-analyticalmethod,whichhassatisfactorycomputationeffectivenessandprecision,ispresentedforsolvingtheacousticradiationfromasubmergedinfinitenon-circularcylindricalshellstiffenedbylongitudinalribsbymeansoftheFourierintegraltransformationandstationaryphasemethod.Inthiswork,besidesthenormalinteractingforce,whichiscommonlyadoptedbysomeresearchers,theotherinteractingforcesandmomentsbetweenthelongitudinalribsandthenon-circularcylindricalshellareconsideredatthesametime.Theeffectsofthenumberandthesizeofthecross-sectionoflongitudinalribsonthecharacteristicsofacousticradiationareinvestigated.NumericalresultsshowthatthemethodproposedismoreefficientthantheexistingmixedFE-BEmethod.

  • 标签: 同源体积高精度积分法 光谱法 矩阵转换法 柱形壳强化
  • 简介:Amathematicalmodelofapredator-preymodelwithIvlev'sfunctionalresponseconcerningintegratedpestmanagement(IPM)isproposedandanalyzed.Weshowthatthereexistsastablepest-eradicationperiodicsolutionwhentheimpulsiveperiodislessthansomecriticalvalues,Furthermore,theconditionsforthepermanenceofthesystemaregiverl.Byusingbifurcationtheory,weshowtheexistenceandstabilityofapositiveperiodicsolution.Theseresultsarequitedifferentfromthoseofthecorrespondingsystemwithoutimpulses.Numericalsimulationshowsthatthesystemweconsiderhasmorecomplexdynamicalbehaviors.Finally,itisprovedthatIPMstrageyismoreeffectivethantheclassicalone.

  • 标签: DHTML编辑器 模型 功能响应 有害物综合管理 节肢动物 周期
  • 简介:Fastsolvinglarge-scalelinearequationsinthefiniteelementanalysisisaclassicalsubjectincomputationalmechanics.Itisakeytechniqueincomputeraidedengineering(CAE)andcomputeraidedmanufacturing(CAM).Thispaperpresentsahigh-efciencyimprovedsymmetricsuccessiveover-relaxation(ISSOR)preconditionedconjugategradient(PCG)method,whichmaintainstheconvergenceandinherentparallelismconsistentwiththeoriginalform.Ideally,thecomputationcanbereducednearlyby50%ascomparedwiththeoriginalalgorithm.Itissuitableforhigh-performancecomputingwithitsinherentbasichigh-efciencyoperations.Bycomparingwiththenumericalresults,itisshownthattheproposedmethodhasthebestperformance.

  • 标签: 预处理共轭梯度法 大型线性方程组 有限元分析 松弛 对称 计算机辅助制造
  • 简介:Heattransportatthemicroscaleisofvitalimportanceinmicrotechnologyapplications.Theheattransportequationisdifferentfromthetraditionalheattransportequationsinceasecondorderderivativeoftemperaturewithrespecttotimeandathird-ordermixedderivativeoftemperaturewithrespecttospaceandtimeareintroduced.Inthisstudy,wedevelopahybridfiniteelement-finitedifference(FE-FD)schemewithtwolevelsintimeforthethreedimensionalheattransportequationinacylindricalthinfilmwithsubmicroscalethickness.Itisshownthattheschemeisunconditionallystable.Theschemeisthenemployedtoobtainthetemperatureriseinasub-microscalecylindricalgoldfilm.Themethodcanbeappliedtoobtainthetemperatureriseinanythinfilmswithsub-microscalethickness,wherethegeometryintheplanardirectionisarbitrary.

  • 标签: 混合有限元-有限差分格式 热传导方程 圆柱薄膜 半微尺度厚度 非条件稳定 温度
  • 简介:摘要在供电企业当中,电力营销管理在其实际发展与运营期间占据着十分重要的地位,有着非常核心的作用。从某种意义上来说,电力营销管理工作的质量及效率能够直接影响到企业的实际运营情况,因此,对于供电企业而言,秉着与时俱进的思想理念,树立创新意识,不断优化电力营销策略,实现电力营销管理工作质量与效率的提升是十分必要的。鉴于此,供电企业应该结合实际情况,对实际工作中存在的问题进行深度剖析,并采取科学合理的措施,进一步推动供电企业经济效益与社会效益的双效提升。

  • 标签: 供电企业 电力营销 策略
  • 简介:摘要在供电企业当中,电力营销管理在其实际发展与运营期间占据着十分重要的地位,有着非常核心的作用。从某种意义上来说,电力营销管理工作的质量及效率能够直接影响到企业的实际运营情况,因此,对于供电企业而言,秉着与时俱进的思想理念,树立创新意识,不断优化电力营销策略,实现电力营销管理工作质量与效率的提升是十分必要的。鉴于此,供电企业应该结合实际情况,对实际工作中存在的问题进行深度剖析,并采取科学合理的措施,进一步推动供电企业经济效益与社会效益的双效提升。

  • 标签: 供电企业 电力营销 策略
  • 简介:发展中国家科学院(原第三世界科学院)第26届院士大会2015年11月18日在奥地利首都维也纳召开。全国大学生数学建模竞赛组委会副主任陈永川、组委会成员亚湘在会上当选为发展中国家科学院院士。此次发展中国家科学院共增选44名院士,其中有13位来自中国(含香港、台湾地区);数学学科共增选4位院士,除陈永川、亚湘院士之外,国立台湾大学的于靖教授、美国杜克大学的Ingrid

  • 标签: 袁亚湘 国家科学院院士 组委会成员 第三世界科学院 数学建模竞赛 台湾大学