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500 个结果
  • 简介:这篇论文讨论加速为解决非线性的抛物线的方程的含蓄的计划的反复的方法。二个新非线性的反复的方法由theimplicit明确的伪说出--牛顿(IEQN)方法和衍生物免费的含蓄明确的伪--牛顿(DFIEQN)方法被介绍,在哪个结果从linearization的线性方程能保存原来的部分微分方程的抛物线的特征。重复方法的反复的顺序能集成二次的联盟者到含蓄的计划的答案,这被证明。而且与Jacobian免费Newton-Krylov(JFNK)方法相比,theDFIEQN方法有一些优点,例如,它的实现是容易的,并且它与一个明确的系数矩阵给一个线性代数学的系统,以便线性(内部)重复没被限制为Krylov方法。由IEQN,DFIEQN,JFNK和Picard重复方法的计算结果在理论的证实和这些方法的表演的比较被介绍。

  • 标签: 非线性抛物线方程 误差图解 牛顿迭代法 计算数学
  • 简介:Introducingbasicdesignmethodologyfordevelopingbacksteppingnonlinearcontrollerforvibrationcontrolsystem.Withasimplifiedsecond-ordersystemmodelofnonlinearvibrationsystem(Duffing’sequation),where,theprocesshasillustratedthebacksteppingdesignstep-by-step.Backsteppingisanovelnonlineardesigntool,whichisbasedonconstructingtheLyapunovfunctionfortheclosed-loopsystemsandguaranteesthestabilityandtrackingperformancethroughenergydissipation.Ingeneral,thisnonlinearcontroldesignapproachgeneratesaggressivecontrolefforttoreducethetrackingerrorpresentedinthiscontrolsystemandsignificantlyimprovethesystembandwidth.Theeffectivenessofthedesignschemeisshownthroughthecomputersimulation.

  • 标签: 非线性振动系统 非线性控制器 设计方法 NOVELL 反推 Lyapunov函数
  • 简介:Abstract.OgrobjectinthisartlcleistodescribetbeGalerklnschemeandnonlin-eaxGalerkinschemefortheapproximationofnonlinearevolutionequations,andtostudythestabilityoftheseschemes.SpatialdiscretizatloncanbepedormedbyeitherGalerklnspectralmethodornonlinearGalerldnspectralmethod;timediscretizatlortisdonehyEulersin.heinewklchisexplicitorimplicitinthenonlinearterms.Accordingtothestabilityanalysisoftheaboveschemes,thestabilityofnonllneexGalerklnmethodisbetterthanthatofGalexklnmethod.

  • 标签: 非线性发展方程 非线性GALERKIN方法 稳定性分析 偏微分方程 耗散型方程
  • 简介:在这研究,一条新分析途径被开发分析保守two-degree-of-freedom(TDOF)的免费非线性的颤动系统。这些系统的数学模型被秒顺序管理非线性的部分微分方程。非线性的微分方程被使用一些中间的变量变成一个单个方程。单个非线性的微分方程被使用Hamiltonian途径的第一份订单解决(哈)。不同参数,在系统的反应上有重要影响,被考虑并且讨论。一些比较被介绍验证在Hamiltonian途径和准确答案之间的结果。最大的相对错误是为颤动的大振幅的不到2.2124%。Hamiltonian途径的第一次重复完成很精确的结果,这被建立了,不要求任何小不安,并且能被用于大量非线性的问题。

  • 标签: 影响系统 非线性动力学 自由程 非线性刚度 二阶非线性偏微分方程 非线性微分方程组
  • 简介:Nonlinearmetailogenicdynamicsisoneofthodifficultprob1emsthatcommonlyfacemoderncom-plcxscicnces.TheRussianfamousmetallogenjstA.D.Shcbeglov(1988)paidattentiontotheprob1emofnonlin-earmctal1ogenyandproposedthcconceptofnonlinearmcta11ogeny.HepointedoutthatthercjSane-cessityofamoredetailedandcomprchensive

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  • 简介:ALaplacedecompositionalgorithmisadoptedtoinvestigatenumericalsolutionsofaclassofnonlinearpartialdiferentialequationswithnonlineartermofanyorder,utt+auxx+bu+cup+du2p1=0,whichcontainssomeimportantequationsofmathematicalphysics.Threedistinctinitialconditionsareconstructedandgeneralizednumericalsolutionsaretherebyobtained,includingnumericalhyperbolicfunctionsolutionsanddoublyperiodicones.Illustrativefiguresandcomparisonsbetweenthenumericalandexactsolutionswithdiferentvaluesofpareusedtotesttheefciencyoftheproposedmethod,whichshowsgoodresultsareachieved.

  • 标签: 非线性偏微分方程 LAPLACE 非线性项 任意阶 分解法 求解
  • 简介:Weexperimentallyinvestigatedthenonlinearopticalresponseinfew-layeroxidizedblackphosphorus(OBP)bythefemtosecondZ-scanmeasurementtechnique,andfoundthatOBPnotonlypossessesstrongultrafastsaturableabsorptionbutalsoanonlinearself-defocusingeffectthatisabsentinblackphosphorus(BP).Thesaturableabsorptionpropertyoriginatesmainlyfromthedirectbandstructure,whichisstillmaintainedinOBP.Theemergenceofself-defocusingmightoriginatefromthecombinedconsequencesoftheoxygen-induceddefectsinBP.Ourexperimentalfindingsmightconstitutethefirstexperimentalevidenceonhowtodynamicallytuneitsnonlinearproperty,offeringaninroadintailoringitsopticalpropertiesthroughchemicalmodification(oxidation,introducingdefects,etc.).Theversatileultrafastnonlinearopticalproperties(saturableabsorptionandself-defocusing)implyasignificantpotentialofthelayeredOBPinthedevelopmentofunprecedentedoptoelectronicdevices,suchasmodelockers,opticalswitches,laserbeamshapers,andwavelengthconverters.

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  • 简介:一个古典抑制矩阵的性能,从起始的结构的性质或当前的结构的性质的使用的构造任何一个,在自由(MDOF)的非线性的多重度的一步一步的解决方案,系统是评估的经分解。分析结果被数字例子证实。因而,一些结论从可能为实际应用被认为指南同样不平的这些分析结果被得出。从起始的结构的性质构造的一个古典抑制矩阵为实际应用是足够的,这被发现,自从它近似有由当前的结构的性质获得了的一样的抑制效果并且以计算是更有效的。

  • 标签: 非线性性能 阻尼矩阵 多自由度 结构特性 构造解析 结构属性
  • 简介:Anonlinearage-dependentpopulationmodel,whichallowsforconsiderationoftheeffectsofcrowdingandresourcelimitation,ispresented.Thebasicpropertiesofsolution,suchasexistence,positivity,uniqueness,andultimatebehavior,arediscussed.Also,theconditionofstabilityandcontroll-abilityofthenonlinearpopulationsystemisobtained.

  • 标签: SEMIGROUP EXISTENCE of SOLUTION STABILITY
  • 简介:各种各样的途径为解决许多连续全球优化问题被开发了。但是直到现在,更少的工作被奉献给由于固有的困难解决非线性的整数编程问题。这篇论文设法把一般非线性的整数编程问题转变成一个equivalent'专辑连续全球最小化问题。因此,任何有效全球优化算法能被用来解决非线性的整数编程问题。这结果将也在全球优化上支持研究。我们在场一个间隔Branch-and-Bound算法。数字实验证明这条途径是有效的。(作者摘要)11个裁判员。

  • 标签: INTEGER PROGRAMMING Global MINIMIZATION PROBLEM Branch-boundalgorithm.
  • 简介:Thispaperpointsoutthatsynchronizationofhyperchaosmaybeachievedbyanonlinearfeedbackwithoutdecomposingtheoriginalsystem.ItappliestheideastoRosslersystem,anddiscussesseveralformsofnonlinearfeedbachbyLyapunovfunctionandnumericalcalculation.

  • 标签: 同步高噪声 非线性反馈 李雅普诺夫函数
  • 简介:Anonlinearshort-wave-averaged(surfbeat)modelispresented.ThemodelisbasedonthatofRoelvink(1993),butthenumericaltechniquesusedinthesolutionarebasedontheso-calledweighted-averagedflux(WAF)method(egWatsonetal.,1992),withtime-operatorsplittingusedforthetreatmentofsomeofthesourceterms.Thismethodallowsasmallnumberofcomputationalpointstobeused,andisparticularlyefficientinmodellingbreakinglongwaves.Theshort-wave(orprimary-wave)energyequationissolvedusingamoretraditionalLax-Wendrofftechnique.Resultsofvalidationindicatethatthemodelperformssatisfactorilyinmostrespects.

  • 标签: SURF BEAT LONG WAVE SURF ZONE
  • 简介:WeproposeanewmethodforfindingthelocaloptimalpointsoftheconstrainednonlinearprogrammingbyOrdinaryDifferentialEquations(ODE),andproveasymptoticasymptoticstabilityofthesingularpointsofpartialvariablesinthispaper.Theconditionofoveralluniform,asymptoticstabilityisalsogiven.

  • 标签: 非线性程序 常微分方程 渐近线稳定性
  • 简介:LetXdenoteacomplexanalyticmanifold,andletAut(X)denotethespaceofinvertiblemapsofagerm(X,a)toagerm(X,b);thisspaceisobviouslyagroupoid;roughlyspeaking,a'Liegroupoid'isasubgroupoidofAut(X)definedbyasystemofpartialdifferentialequations.ToafoliationwithsingularitiesonXoneattachessuchagroupoid,e.g.thesmallestonewhoseLiealgebracontainsthevectorfieldstangenttothefoliation.Itiscalled'theGaloisgroupoidofthefoliation'.Someexamplesareconsidered,forinstancefoliationsofcodimensionone,andfoliationsdefinedbylineardifferentialequations;inthislastcaseonerecuperatestheusualdifferentialGaloisgroup.

  • 标签: 非线性微分方程 微分Galois群 复解析流形 包络 Lie广群 LIE对称
  • 简介:Basedonthenotionofmaximalabsoluteobservabilityanditsnormalforms,anewmethodforstudyingthelocalstabilizationforakindofnonlinearcontrolsystemsisestablished.DifferentfromthepreviousresultsgivenbyByrnes-Isitoriandothers,thisnewmethodcandealwithmoregeneralsystems,andhasmuchsimplerwaytoprovethestabilizationconditionsandtodesignthefeedbacklaws.

  • 标签: Nonlinear control ABSOLUTE OBSERVABILITY ZERO DYNAMICS
  • 简介:Thespectralpropertiesofnonlineardragforcesofrandomwavesonverticalcircularcylindersareanalyzedinthispaperbymeansofnonlinearspectralanalysis.Theanalysisprovidesbasicparametersforestimationofthecharacteristicdragforces.Numericalcomputationisalsoperformedfortheinvestigationoftheeffectsofnonlinearityofthedragforces.TheresultsindicatethatthewavedragforcescalculatedbylinearwavetheoryarelargerthanthosecalculatedbythethirdorderStokeswavetheoryforgivenwaves.Thedifferencebetweenthemincreaseswithwaveheight.Thewavedragforcescalculatedbyuseoflinearapproximationareabout5%smallerthantheiractualvalueswhenmeasuredinthepeakvaluesofspectraldensities.Thiswillresultinasafetyproblemforthedesignofoffshorestructures.Therefore,thenonlineareffectofwavedragforcesshouldbetakenintoconsiderationindesignandapplicationofimportantoffshorestructures.

  • 标签: 海上工程 随机波动驱动力 非线性 光谱性质 斯托克斯波动
  • 简介:本文首次给出了非线性随机效应模型参数估计弱相合性的必要条件,并证明了在一定正则条件下估计的强相合性和渐近正态性,推广了BreslowandCalyton(1993),LeandNelder(1996)的结果.

  • 标签: 固定效应 随机效应 边缘似然