简介:PresentedbytheWorldWindEnergyAssociation(WWEA)andtheChineseWindEnergyAssociation(CWEA),theThirdWorldWindEnergyConference(WWEC2004)washeldinBeijinginNovember2004.AtthattimeChinajuststartedtodevelopwindpowerindustryinlargescale.Internationalorganizationsandgovernmentagenciesrelatedtoenergyandenvironmentalissueswereat-
简介:Thereareseveralpetawatt-scalelaserfacilitiesaroundtheworldandthefidelityofthepulsestotargetiscriticalinachievingthehighestfocusedintensitiesandthehighestpossiblecontrast.TheUnitedKingdomhasthreesuchlaserfacilitieswhicharecurrentlyopenforaccesstotheacademiccommunity:OrionatAWE,AldermastonandVulcan&Astra-GeminiattheCentralLaserFacility(CLF),STFC(ScienceandTechnologyFacilitiesCouncil)RutherfordAppletonLaboratory(RAL).Thesefacilitiesrepresentthetwomainclassesofpetawattfacilities:themixedOPCPA/Nd:glasshigh-energysystemsofOrionandVulcanandtheultra-short-pulseTi:SapphiresystemofAstraGemini.Manyofthetechniquesusedtoenhanceandcontrolthepulsegenerationanddeliverytotargethavebeenpioneeredonthesefacilities.Inthispaper,wepresentthesystemdesignswhichmakethispossibleanddiscussthecontrastenhancementschemesthathavebeenimplemented.
简介:InvehicularAd-hocnetwork(VANET),manymulti-hopbroadcastschemesareemployedtowidelypropagatethewarningmessagesamongvehiclesandthekeyistodynamicallydeterminetheoptimalrelayvehicleforretransmission.Inordertoachievereliableandfastdeliveryofwarningmessages,thispaperproposesadelay-awareandreliablebroadcastprotocol(DR-BP)basedontransmitpowercontroltechnique.First,acomprehensivemodelisderivedtoevaluatethetransmissioninvehicle-to-vehiclecommunications.Thismodelconsidersthewirelesschannelfading,transmissiondelayandretransmissionscharactersoccurringinthephysicallayer/mediumaccesscontrol(PHY/MAC)layer.Then,alocaloptimalrelayselectionmechanismbasedontheabovemodelisdesigned.InDR-BPscheme,onlythevehicleselectedastheoptimalrelayscanforwardwarningmessagesandthetransmitpoweristime-varying.Finally,extensivesimulationsverifytheperformanceofDR-BPunderdifferenttrafficscenarios.SimulationresultsshowthatDR-BPoutperformsthetraditionalslotted1-persistence(S1P)andfloodingschemeintermsofpacketsdeliveryratioandtransmissiondelay.
简介:Withtheincreasingpenetrationofrenewableenergysourceswithawiderangeofoperatingconditionscausingpowersystemuncertainties,conventionalcontrollersareincapableofprovidingproperperformancetokeepthesystemstable.However,controllableordispatchableloadssuchaselectricvehicles(EVs)andheatpumps(HPs)canbeutilizedforsupplementaryfrequencycontrol.Thispapershowstheabilityofplug-inhybridEVs,HPs,andbatteries(BTs)tocontributeinthefrequencycontrolofanisolatedpowersystem.Moreover,weproposeanewonlineintelligentapproachbyusingacoefficientdiagrammethod(CDM)toenhancethesystemperformanceandrobustnessagainstuncertainties.TheperformanceoftheproposedintelligentCDMcontrolhasbeencomparedwiththeproportional-integral(PI)controllerandthesuperiorityoftheproposedschemehasbeenverifiedinMatlab/Simulinkprograms.
简介:Unsteadymotionofaverticallyfallingnon-sphericalparticlehasattractedconsiderableattentionduetoitsfrequentapplicationsinnatureandindustry.Aseriesofsemi-analyticalmethodshavebeenusedtoraisetheresults’accuracyaswellaswideningtheregionofconvergence.Thecurrentstudypursuedanewanalyticalsolutionfortheunsteadymotionofarigidnon-sphericalparticleinaquiescentNewtonianfluid,basedontheOptimalHomotopyAnalysisMethod.Withaviewtowardsobtainingthehighestlevelofaccuracyandensuringtheconvergenceoftheanalyticalresults,theaveragedresidualerrorswereobtainedandminimized.Inadditiontoflexibility,itwasalsoproventhattheproposedmethodcanleadtocompletelyreliableandpreciselyaccurateresults.Basedontheseriessolution,theeffectsofphysicalparametersontheterminalsettlingvelocity(i.e.thegreatestvelocitythatafallingbodymayreach)andtheaccelerationtime(i.e.thetimethataparticlereachesthesettlingvelocity)areinvestigated.
简介:Non-sphericalmicronandnano-sizedparticlesandtheircompositeshavebecomeessentialinselectapplicationareasofoptics,wearresistance,personnelprotection,chemicalmechanicalpolishing,andbiomedicine.Inthispaper,thesynthesisofcompositeandceramicnon-sphericalparticlesusingstopflowlithographyisreported.Precursorsuspensionsofpoly(ethyleneglycol)diacrylate,2-hydroxy-2-methylpropiophenoneandSiO2orAl2O3areprepared.Theprecursorsuspensionflowsthroughamicrofluidicdevicemountedonanuprightmicroscopeandispolymerizedinanautomatedprocess.Aphotomaskpatternedwithtransparentgeometricfeatures,whichdefinethecross-sectionalshapesoftheparticles,maskstheUVlighttosynthesizemicronsizedparticles.Particleswithaxialdimensionsrangingfrom35to167μmweresynthesized.Controlofdevicechanneldepthandobjectivelensmagnificationenablesthemanipulationoftheparticlesize.Compositeparticlesintriangular,square,pentagonal,hexagonal,andcircularcrosssectionsweresynthesized.Subsequently,thetransformationofthecompositeparticlesintothecorrespondingmetaloxideparticleswasachievedthroughpolymerburn-offandsintering.
简介:Non-uniformalgebraic-trigonometricB-splinessharesmostofthepropertiesasthoseoftheusualpolynomialB-splines.Buttheyarenotorthogonal.Weconstructanorthogonalbasisforthen-order(n≥3)algebraic-trigonometricsplinespaceinordertoresolvethetheoreticalproblemthatthereisnotanexplicitorthogonalbasisinthespacebynow.MotivatedbytheLegendrepolynomials,wepresentanovelapproachtodefineasetofauxiliaryfunctions,whichhavesimpleandexplicitexpressions.Thentheproposedorthogonalsplinesaregivenasthederivativesoftheseauxiliaryfunctions.
简介:Thispaperpresentsanewapproachtosolvemixed-variableunitcommitment(UC)problemswithnon-smoothcostfunctionsbasedonageneralizedpatternsearchfilter(GPS-filter)algorithm.AGPS-filteralgorithmdoesnotrequireanyinformationaboutthegradientoftheobjectivefunctionwhilesearchingforanoptimumsolution.Atthesametime,itisavailableforsolvingmixed-variableoptimizationproblems,whichisverysuitableforUC.AnewsuitablediscreteneighborhoodstructurewithUCcharacteristicsisproposedtoimproveGPS-filterefficiently.Alotofmultipleunits'statesarefixedbeforesearch;hence,thepollingsearchofdiscretevariableisefficientforafewuncertainunits.Numericalexperimentsareincludedtodemonstratetheproposedapproach'sabilitytohandlethehighlynonlinear,discontinuous,non-smoothcostfunctionsandmixedvariablesoftheUCproblem.
简介:AnoverviewoftheCzechnationalR&DprojectHiLASE(Highaveragepowerpulsedlaser)ispresented.Theprojectfocusesonthedevelopmentofadvancedhighrepetitionrate,diodepumpedsolidstatelaser(DPSSL)systemswithenergiesintherangefrommJto100Jandrepetitionratesintherangefrom10Hzto100kHz.Someapplicationsoftheselasersinresearchandhi-techindustryarealsopresented.
简介:Aimingtoreducethecomputationalcostsandconvergetoglobaloptimum,anovelmethodisproposedtosolvetheoptimizationofacostfunctionintheestimationofdirectionofarrival(DOA).Inthismethod,ageneticalgorithm(GA)andfuzzydiscreteparticleswarmoptimization(FDPSO)areappliedtooptimizethedirectionofarrivalandpowerparametersofthemodesimultaneously.Firstly,theGAalgorithmisappliedtomakethesolutionfallintotheglobalsearching.Secondly,theFDPSOmethodisutilizedtonarrowdownthesearchfield.InFDPSO,achaoticfactorandacrossovermethodareaddedtospeeduptheconvergence.Thisapproachhasbeendemonstratedthroughsomecomputationalsimulations.ItisshownthattheproposedalgorithmcanestimateboththeDOAandthepowersaccurately.Itismoreefficientthansomepresentmethods,suchastheNewton-likealgorithm,Akaikeinformationcritical(AIC),particleswarmoptimization(PSO),andgeneticalgorithmwithparticleswarmoptimization(GA-PSO).
简介:Non-centernetworkcomputingenvironmentshavesomeuniquecharacteristics,suchasinstability,heterogeneity,autonomy,distributionandopenness,whichbringseriousissuesofsecurityandreliability.Thisarticleproposesabrand-newcredibilityprotectionmechanismforresourcesharingandcollaborationinnon-centernetworkcomputingenvironments.First,thethree-dimensionalhierarchicalclassifiedtopology(3DHCT)isproposed,whichprovidesabasicframeworkforrealizationsoftheidentitycredibility,thebehaviorcredibilityandthecapabilitycredibility.Next,theagenttechnologyisutilizedtoconstructthecredibilityprotectionmodel.Thisarticlealsoproposesanewcomprehensivecredibilityevaluationalgorithmwithsimple,efficient,quantitativeandabletomeettherequirementsofevaluatingbehaviorcredibilityandthecapabilitycredibilityevaluationaswell.TheDempster-Shafertheoryofevidenceandthecombinationruleareusedtoachievetheevaluationofthecapabilitycredibility.Thebehaviorcredibilityisevaluatedwiththecurrentandhistoricalperformanceofnodesforprovidersandconsumerstorealizemoreaccurateprediction.Basedonthenon-centernetworkcomputingsimulationtestplatform,simulationisbeenconductedtotesttheperformanceandvalidityoftheproposedalgorithms.Experimentandanalysisshowthattheproposedalgorithmsaresuitableforlarge-scale,dynamicnetworkcomputingenvironments,andabletomaintainthecredibilityfornetworkswithoutrelyingoncentralnode,makeanon-centernetworkgraduallyevolveintoanorderly,stableandreliablecomputingenvironmentefficiently.
简介:Multilayerdielectricthinfilmedgefilterhasseriouspolarizationsensitivityunderobliqueincidence.Thecutoff-bandsofthes-polarizationandp-polarizationlightinconventionaledgefilterwillseparateobviouslyunder45°obliqueincidence,whichlimitsitsapplication.BasedonthetwochosenmaterialsTiO2andSiO2,anovelstackstructureisproposedtodesignthenon-polarizationshort-wave-passthinfilmedgefilter.Byusingthe(4H4L4H)asthematchinglayers,thepolarizationseparationat3dBtransmittanceforthethinfilmedgefiltercutoff-bandislessthan1nmattheincidentangleof45°.Inthisway,thenon-polarizationshort-wave-passedgefilteriseasilydesignedandfabricated.