简介:TheexistenceofatleasttwohomoclinicorbitsforLagrangiansystem(LS)isproved,wheretheLagrangianL(t,x,y)=1/2∑aij(x)yiyi-V(t1x),inwhichthepotentialV(t,x)isgloballysurperquadraticinxandT-periodicint.TheConcentration-CompactnessLemmaandMinimaxargumentareusedtoprovetheexistences.
简介:Inthispaper,thescrewtransformationsarediscussedindetailandtheirmatricesaregiven.BasedonLagrangianequations,anewmethodformodellingthedy-namicbehaviorofrobotsispresented.Thederivationissimple,andtheconfigurationofthemodelisconcise.Allthecoefficientsarecalculatedinsimplerecursiveway,whichcanbeeasilyprogrammedincomputation.Themethodpresentedcanalsobeusedinthedy-namicandthekinematicstudyofspatialmechanisms.
简介:WeintroducetheEuler-LagrangecohomologytostudythesymplecticandmultisymplecticstructuresandtheirpreservingpropertiesinfiniteandinfinitedimensionalLagrangiansystemsrespectively.WealsoexploretheircertaindifferencediscretecounterpartsintherelevantregularlydiscretizedfiniteandinfinitedimensionalLagrangiansystemsbymeansofthedifferencediscretevariationalprinciplewiththedifferencebeingregardedasanentiregeometricobjectandthenoncommutativedifferentialcalculusonregularlattice.InordertoshowthatinallthesecasesthesymplecticandmultisymplecticpreservingpropertiesdonotnecessarilydependontherelevantEuler-Lagrangeequations,theEuler-Lagrangecohomologicalconceptsandcontentintheconfigurationspaceareemployed.``
简介:Accordingtothenaiveconstituentquarkmodel,the?mesonisbelievedtobeanalmostpuressstate,whilethereareonlyupanddownquarks(antiquarks)inthenucleon(antinucleon).Thusthepp!??reaction,withitsdisconnectedquarklines,shouldbesuppressedaccordingtotheOkubo-Zeig-Iizuka(OZI)rule.However,eventheOZIruleisstrictlyenforcedbynature,theppreactioncanstillproceedthroughthenon-strangequarkcomponentofthe?meson,becauseoftheslightdiscrepancyfromtheidealmixingofthevectormesonsingletandoctet[1].Withthissmalldiscrepancy,onecandetermineanupperlimitforthetotalcrosssectionofpp!??reactionbycomparisontothetotalcrosssectionoftherelatedpp!ωωreaction.Thisyieldsacrosssectionforpp!??attheorderof10nb.However,theexperimentalresultshowedthatthecrosssectionat1.2GeVincidentanti-protonmomentum,=2.860.46μb,istwoordersofmagnitudelargerthantheestimatedvalue.Hence,thepp!??reactionhasattractedmuchattentionbecauseofthelargeviolationoftheOZIrule.
简介:Inthispaper,wehavesuggestedseveralinterpolatingformulaewhichareconvinientforvectorcom-puterstoperformvectorcalculation.Analysisshowsthatforasimpleadvectiveproblem,thesemi-Lagrangianschemesconstructedwiththeseformulaearelinearlyunconditionallystable.Moreover,wehavediscussedthenonlinearcomputationalchaosinthesemi-Lagrangianschemes.Itisfoundthatforasimplenonlinearadvectiveproblem,wecanintroducephysicallyunrealanddirectinteractionofthreeormorewaves.Nu-mericaltestsindicatethatthisphenomenonhascertaininfluenceonthesimulatedresultsoftwo-dimensionalBenardconvection.
简介:Basedonanewdefinitionofnonlocalvariable,thispaperestablishestheLagrangianformulationforcontinuumwithinternallong-rangeinteractions.Distinguishedfromtheexistingtheories,thenonlocaltermintheLagrangianformulationautomaticallysatisfiesthezeromeanconditiondeterminedbytheactionandreactionlaw.Bythisformulation,elasticwaveinarodwiththeinternallong-rangeinteractionsisinvestigated.Thedispersionoftheelasticwaveispredicted.
简介:这份报纸考虑最佳的公事包deleveraging的问题,它是在金融的一个关键问题。拿进帐号跨影响的永久、暂时的价格,作者与框限制和单身地二次的限制建立一个二次的程序。在一些假设下面,当二次的限制是活跃的时,作者给最佳的答案必须被完成的最佳的做贸易优先级和表演。进一步,作者为模型建议一个适应Lagrangian算法,在的地方piecewise二次的发现根的方法被用来更多样地发现Lagrangian。算法的集中被建立。作者也介绍一些数字结果,它显示出算法的实用性并且验证最佳的做贸易优先级。
简介:ThepreviouspaperreportedanewderivativeintheEuleriandescriptioninflatspace—thegeneralizedcovariantderivativeofgeneralizedEuleriancomponentwithrespecttotime.ThispaperextendsthethoughtfromtheEuleriandescriptiontotheLagrangiandescription:onthebasisofthepostulateofcovariantforminvariabilityintimefield,wedefineanewderivativeintheLagrangiandescriptioninflatspace—thegeneralizedcovariantderivativeofgeneralizedLagrangiancomponentwithrespecttotime.Besides,thecovariantdifferentialtransformationgroupissetup.ThecovariantforminvariabilityofLagrangianspace-timeisascertained.
简介:有双性人目标策略的一个扩充Lagrangian信任区域方法被建议因为解决非线性的平等抑制了优化,它在惩罚类型方法和没有惩罚的之间掉落。在每次重复,试用步被在一个信任区域以内最小化一个二次的近似模型到扩充Lagrangian功能计算。模型是为非强迫的优化的标准信任区域subproblem并且能被许多存在方法高效地因此解决。选择惩罚参数,辅助信任区域subproblem与限制违背有关被介绍。结果,惩罚参数不必monotonically正在增加并且不趋于到无穷。双性人目标策略,与客观功能和限制违背的措施有关,被利用决定试用步是否将被接受。方法的全球集中在温和假设下面被建立。数字实验被做,它在各种各样的困难的状况上说明算法的效率。
简介:Becauseofshoaling,refraction,friction,andothereffects,asurface-wavepropagatingonagentlyslopingbottomofslopewilleventuallybreak.Inthispaper,bynonlinearizingtheproblemandusingaperturbationmethod,ananalyticalsolutionforthevelocitypotentialisderivedtothesecondorderforthebottomslopeαandthewavesteepnessεinaEuleriansystem.Then,thewaveprofileandthebreakingwavecharacteristicsarefoundbytransformingtheflowfieldintoaLagrangiansystem.Byuseofthekinematicstabilityparameter(K.S.P.),newtheoreticalbreakercharacteristicsarederived.Thus,thelineartheoriesofotherscholarsareextendedtobreakingwaves.AComparisonofthepresentanalyticalsolutionwithexperimentalstudiesofotherscholarsshowsreasonableagreementexceptthatthebreakingdepthisunderestimated.
简介:在这份报纸,我们使用任意的Riemann解答者,它不能满足Maire的要求,到Maire发展在的基于节点的Lagrangian计划[P.H。Maire等,暹罗J。Sci。Comput,29(2007),1781-1824]。特别地,我们使用所谓的多液体隧道onAveraged体积(MFCAV)Riemann解答者和适应地把MFCAV解答者与另外的更消散的Riemann解答者相结合到Maire的计划的一个Riemann解答者。任何一个二个解答者都不满足Maire的要求,这被注意。数字实验被介绍证明二个Riemann解答者的应用程序是成功的。[从作者抽象]
简介:AnewapproachfortreatingthemeshwithLagrangianschemeoffinitevolumemethodispresented.IthasbeenprovedthatclassicalLagrangianmethodisdifficulttocopewithlargedeformationintrackingmaterialparticlesduetoseveredistortionofcells,andthechangingconnectivityofthemeshseemsespeciallyattractiveforsolvingsuchissues.Themeshwithlargedeformationbasedoncomputationalgeometryisoptimizedbyusingnewmethod.Thispaperdevelopsaprocessingsystemforarbitrarypolygonalunstructuredgrid,theintelligentvariablegridneighborhoodtechnologiesisutilizedtoimprovethequalityofmeshincalculationprocess,andarbitrarypolygonalmeshisusedintheLagrangianfinitevolumescheme.Theperformanceofthenewmethodisdemonstratedthroughseriesofnumericalexamples,andthesimulationcapabilityisefficientlypresentedincopingwiththesystemswithlargedeformations.
简介:Inthispaper,atwo-dimensional(2-D)Lagrangiantechniqueforflowfieldmeasurementunderhighdynamicpressureispresented,whichincludesasetofexperimentaldeviceand2-DLagrangecompositemanganin-constantanringgages.Withthiskindofgage,thehistoriesofpressureandradialdisplacementcanbemeasuredsimultaneouslyatdifferentLagrangepositionsinanaxisymmetricshockloadingflowfield.Thetechniquehassomeadvantagesoverthe1-Done,suchas,simplifiedloadingdevice,continuouslyadjust-ableoutputpressure,norestrictiononsamplelengthandtheavailabilityforthestudyoflateralrarefactioninshockpropogation.Asapreliminaryapplication,theprocessesof2-DshockinitiationandattenuationincompactedTNTaremeasured.
简介:Thispaperproposesamixedintegerprogrammingmodelfortheallocationofrailmountedgantrycranesforfourbasicyardactivitieswithdifferentpriorities.Themodelpaysspecialattentiontothetypicalfeaturesofthiskindofgantrycranes,suchasarestrictedtravelingrangeandalimitednumberofadjustmentsduringloadinganddischargingoperations.Incontrasttomostoftheliteraturedealingwiththesefouryardactivitiesindividually,thispapermodelsthemintoanintegratedproblem,whosecomputationalcomplexityisprovedtobeNP-hard.WearethereforemotivatedtodevelopaLagrangianrelaxation-basedheuristictosolvetheproblem.Wecomparetheproposedheuristicwiththebranch-and-boundmethodthatusescommercialsoftwarepackages.Extensivecomputationalresultsshowthattheproposedheuristicachievescompetitivesolutionqualitiesforsolvingthetestedproblems.
简介:AbriefreviewismadeonthetheoryoftheLagrangianresidualcirculationandinter-tidaltransportsinaconvectivelyweaklynonlinearsystem.Inthereviewtheemphasisisputonthesystematicaldevelopmentofthetheoryanditsweaknessofconvectivelyweaklynonlinearapproximation.ThefundamentalsofaLagrangiantidally-averagedtheoryoncirculationwithinter-tidaltransportprocesseshavebeenproposedforageneralnonlinearcoastal/estuarinesystem.TheLagrangianresidualvelocityisstrictlydefined,andithasbeenverifiedtobeabletoembodythevelocityfieldofcirculation.Anewconceptoftheconcentrationforinter-tidaltransportprocessesispresented.Theconcentrationdescribingtheinter-tidaltransportprocessesshouldbea'Lagrangianinter-tidalconcentration'definedandnamed,butnottheEuleriantidally-averagedconcentrationusedtraditionally.Thecirculationdescribedherecontainsasetofinfinitetemporal-spatialfieldsofvelocity/concentration,eachofwhichcorrespondstoaspecificvalueoftidalphasesvaryingcontinuouslyoveronetidalcycle.Whentheconvectivelyweaklynonlinearcondition(withasmallerorderofeddydiffusionandsources)isapproximatelysatisfied,asetofinfinitetemporal-spatialfieldsofvelocity/concentrationcanbereducedtoasingleone:themasstransportvelocity/theEuleriantidallyaveragedconcentrationasexhibitedtraditionally.