简介：Spacecraftsinperiodicorquasi-periodicorbitsnearthecollinearlibrationpointsareprovedtobeexcellentplatformsforscientificinvestigationsofvariousphenomena.Sincesuchperiodicorquasi-periodicorbitsareexponentiallyunstable,thestation-keepingmaneuverisneeded.Astation-keepingstrategywhichisfoundbyananalyticalmethodispresentedtoeradicatethedominantunstablecomponentofthelibrationpointtrajectories.Theinhibitforcetransformstheunstablecomponenttoastable...

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简介：Thispaperaddressesamaster-slavesynchronizationstrategyforcomplexdynamicsystemsbasedonfeedbackcontrol.Thisstrategyisappliedto3-DOFplanarmanipulatorsinordertoobtainsynchronizationinsuchcomplicatedaschaoticmotionsofend-effectors.AchaoticcurveisselectedfromDuffingequationasthetrajectoryofmasterend-effectorandapiecewiseapproximationmethodisproposedtoaccuratelyrepresentthischaotictrajectoryofend-effectors.Thedynamicalequationsofmaster-slavemanipulatorswithsynchronizationcontrollerarederived,andtheLyapunovstabilitytheoryisusedtodeterminethestabilityofthiscontrolledsynchronizationsystem.Innumericalexperiments,thesynchronousmotionsofend-effectorsaswellasthreejointanglesandtorquesofmaster-slavemanipulatorsarestudiedunderthecontroloftheproposedsynchronizationstrategy.Itisfoundthatthepositivegainmatrixaffectstheimplementationofsynchronizationcontrolstrategy.Thissynchronizationcontrolstrategyprovesthesynchronization'sfeasibilityandcontrollabilityforcomplicatedmotionsgeneratedbymaster-slavemanipulators.

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简介：Densegas-particleflowsareencounteredinavarietyofindustriallyimportantprocessesforlargescaleproductionoffuels,fertilizersandbasechemicals.Thescale-upoftheseprocessesisoftenproblematicandisrelatedtotheintrinsiccomplexitiesoftheseflowswhichareunfortunatelynotyetfullyunderstooddespitesignificanteffortsmadeinbothacademicandindustrialresearchlaboratories.Indensegas-particleflowsboth(effective)fluid-particleand(dissipative)particle-particleinteractionsneedtobeaccountedforbecausethesephenomenatoalargeextentgoverntheprevailingflowphenomena,i.e.theformationandevolutionofheterogeneousstructures.Thesestructureshavesignificantimpactonthequalityofthegas-solidcontactandasadirectconsequencethereofstronglyaffecttheperformanceoftheprocess.Duetotheinherentcomplexityofdensegas-particlesflows,wehaveadoptedamulti-scalemodelingapproachinwhichbothfluid-particleandparticle-particleinteractionscanbeproperlyaccountedfor.Theideaisessentiallythatfundamentalmodels,takingintoaccounttherelevantdetailsoffluid-particle(latticeBoltzmannmodel)andparticle-particle(discreteparticlemodel)interactions,areusedtodevelopclosurelawstofeedcontinuummodelswhichcanbeusedtocomputetheflowstructuresonamuchlarger(industrial)scale.Ourmulti-scaleapproach(seeFig.1)involvesthelatticeBoltzmannmodel,thediscreteparticlemodel,thecontinuummodelbasedonthekinetictheoryofgranularflowandthediscretebubblemodel.Inthispaperwegiveanoverviewofthemulti-scalemodelingstrategy,accompaniedbyillustrativecomputationalresultsforbubbleformation.Inaddition,areaswhichneedsubstantialfurtherattentionwillbehighlighted.

简介：Globallook-uptablestrategyproposedrecentlyhasbeenproventobeanefficientmethodtoacceleratetheinterpolation,whichisthemosttime-consumingpartintheiterativesub-pixeldigitalimagecorrelation(DIC)algorithms.Inthispaper,agloballook-uptablestrategywithcubicB-splineinterpolationisdevelopedfortheDICmethodbasedontheinversecompositionalGauss–Newton(IC-GN)algorithm.Theperformanceofthisstrategy,includingaccuracy,precision,andcomputationefficiency,isevaluatedthroughatheoreticalandexperimentalstudy,usingtheonewithwidelyemployedbicubicinterpolationasabenchmark.Thegloballook-uptablestrategywithcubicB-splineinterpolationimprovessignificantlytheaccuracyoftheIC-GNalgorithm-basedDICmethodcomparedwiththeoneusingthebicubicinterpolation,atatrivialpriceofcomputationefficiency.