简介：TheproblemofpicksequencingintherotaryrackS/Rsystem(PPS-RRS)isinvestigatedwiththeobjectiveofminimizingtheexecutiontime.TherotaryrackS/RsystemconsistsofoneS/Rmachineandmultiplelevelsofcarouselsthatcanrotateindependentlyinbi-directions.Theroutingpolicy,namelythedecisiononthestorageorretrievalsequence,dominatestheefficiencyandthethroughputforsuchS/Rsystems,duetothecomplicatedrelationshipbetweenalllevelsofcarouselsandtheS/Rmachine.ForthepurposeofoptimizingthePPS-RRS,acomputationalmodelisdevelopedintermsofexecutiontimeforpickingmultipleitemsinonetrip.CharacteristicsofthePPS-RRSareanalyzedandalocalsearchheuristicbasedonanewlyproposedneighborhoodispresented.Integratedwiththeproposedlocalsearchprocedureanewhybridgeneticalgorithmisdeveloped.Experimentalresultsdemonstratethestructurecharacteristicsofgoodsequenceandtheefficiencyandeffectivenessoftheproposedsequencingalgorithms.

简介：Somenewcriteriaforthechaoticlagsynchronizationareproposed.Atfirst,lagsynchronizationschemeforidenticalmaster-slaveLur'esystemsbyreplacingvariablescontrolandtherelevanterrorsystemaregiven,andtherelationsbetweenabsolutestabilityoftheerrorsystemandthechaoticlagsynchronizationaredescribed.Then,basedonaquadraticLyapunovfunction,twonewLur'ecriteriafortheabovechaoticlagsynchronizationareproved.FourcorrespondingfrequencydomaincriteriaarefurtherderivedbymeansofMeyer-Kalman-YacuboviaLemma.Thesefrequencydomaincriteriaareappliedtoanalyzethelagsynchronizationofgeneralmaster-slaveChua'scircuitssothatsomerangesoftheparametersinwhichthemaster-slaveChua'scircuitsachievechaoticlagsynchronizationbyreplacingsingle-variablecontrolareattained.Finally,someexamplesaregiventoverifythetheoreticalresults.

简介：NecessaryandsuffcientconditionsfortheexistenceofaLyapunovfunctionintheLur'eformtoguaranteetheabsolutestabilityofLur'econtrolsystemswithmultiplenon-linearitiesarediscussedinthispaper.Itsimplifiestheexistenceproblemtooneofsolvingasetoflinearmatrixinequalities(LMIs).IfthoseLMIsarefeasible,freeparametersintheLyapunovfunction,suchasthepositivedefinitematrixandthecoefficientsoftheintegralterms,aregivenbythesolutionoftheLMIs.Otherwise,thisLyapunovfunctiondoesnotexist.Somesufficientconditionsarealsoobtainedfortherobustabsolutestabilityofuncertainsystems.Anumericalexampleisprovidedtodemonstratetheeffectivenessoftheproposedmethod.