简介:AnewclassofconstrainedmultiobjectivegameswithinfiniteplayersinnoncompactlocallyconvexH-spaceswithoutlinearstructureareintroducedandstudied.ByapplyingaFan-Glicksbergtypefixedpointtheoremforuppersemicontinuousset-valuedmappingswithclosedacyclicvaluesandamaximumtheorem,severalexistencetheoremsofweightedNath-equilibriaandParetoequilibriafortheconstrainedmultiobjectivegamesareprovedinnoncompactlocallyconvexH-spaces.Thesetheoremsimprove,unifyandgeneralizethecorrespondingresultsofthemultiobjectivegamesinrecentliteratures.
简介:IntroductionThemostbasicconditionsforfeedbackclosed_loopcontrolofmanipulatorsarethefinestructureandtheefficientreal_timecompu...
简介:Itisconcernedwiththeproblemofdisturbanceattenuationwithstabilityforuncertainnonlinearsystemsbyadaptiveoutputfeedback.Byapartial-stateobserverandBacksteppingtechnique,anadaptiveoutputfeedbackcontrollerwasconstructed,whichcansolvethestandardgaindisturbanceattenuationproblemwithinternalstability.
简介:A3-DnonlinearproblemofsupercavitatingflowpastanaxisymmetricbodyatasmallangleofattackisinvestigatedbymeansoftheperturbationmethodandFourier-cosine-expansionmethod.Thefirstthreeorderperturbationequationsarederivedindetailandsolvednumericallyusingtheboundaryintegralequationmethodanditerativetechniques.Computationalresultsofthehydrodynamiccharacteristicsandcavityshapesofeachorderarepresentedfornonaxisymmetricsupercavitatingflowpastconeswithvariousapex-anglesatdiffer-entcavitationnumbers.Thenumericalresultsarefoundingoodagreementwithexperimentaldata.
简介:TheIsodynetechniquebasedonthescatteredlightscanningfromathinlaserbeamcanbeusedtoobtaintheinformationinsidetheloadedobjectintheroomtemperaturenondestructively,soitisaverypowerfultechniquein3Dstressanalysis.Theproblemsarehowtointerprettheinformationandhowtogetsufficientinformationfromthefewinterferencefringe.Birefringencephaseshifttechniquecandistinguishthefringeordersautomaticallyandenrichtheinformationin256graylevelsbetweenmaximandminimlightintensity.InthepapertheIsodynebirefringencephaseshiftmethodwithanobliqueincidenceandequilibriumequationispresented,bywhichthe3DstressesinthemiddleplaneofaplatewithUshapenotchareseparatedsuccessfully.
简介:BasedupontheHellinger-Reissner(H-R)mixedvariationalprincipleforthree-dimensionalelasticbodies,themodifiedH-Rmixedvariationaltheoremformagnetoelectroelasticbodieswasestablished.Thestate-vectorequationofmagnetoelectroelasticplateswasderivedfromtheproposedtheorembyperformingthevariationaloperations.Tolayatheoreticalbasisofthesemi-analyticalsolutionappliedwiththemagnetoelectroelasticplates,thestate-vectorequationforthediscreteelementinplanewasproposedthroughtheuseoftheproposedprinciple.Finally,itispointedoutthatthemodifiedH-Rmixedvariationalprincipleforpureelastic,singlepiezoelectricorsinglepiezomagneticbodiesarethespecialcasesofthepresentvariationaltheorem.
简介:TheproblemofcheckingrobustD-stabilityofmulti-inandmulti-out(MIMO)systemswasstudied.Threesystemmodelswereintroduced,i.e.multilinearpolynomialmatrix,polytopicpolynomialmatrixandfeedbacksystemmodel.Furthermore,theconvexpropertyofeachmodelwithrespecttotheparametricuncertaintieswasestablishedrespectively.Basedonthis,sufficientconditionsforD-stabilitywereexpressedintermsoflinearmatrixinequalities(LMIs)involvingonlytheconvexvertices.Therefore,therobustD-stabilitywastestedbysolvinganLMIoptimalproblem.
简介:Theboundaryelementmethodwasimprovedforthe2Delasticcompositeswithrandomlydistributedinclusions.Thisproblemcanbereducedtoaboundaryintegralequationforamulti-connecteddomain.Further,consideringthematricesofthetractionsanddisplacementsforeachgroupoftheidenticalinclusionwerethesame,aneffectivecomputationalschemewasdesigned,sincetheordersoftheresultingmatrixequationscanbegreatlyreduced.Numericalexamplesindicatethatthisboundaryelementmethodschemeismoreeffectivethantheconventionalmulti-domainboundaryelementmethodforsuchaproblem.Thepresentschemecanbeusedtoinvestigatetheeffectivemechanicalpropertiesofthefiber-reinforcedcomposites.
简介:Inthepresentpaper,amultifluidmodeloftwo-phaseflowswithpulverized-coalcombustion,basedonacontinuum-trajectorymodelwithreactingparticlephase,isdevelopedandemployedtosimulatethe3-Dturbulenttwo-phaseflowsandcombustioninanewtypeofpulverized-coalcombustorwithoneprimary-airjetplacedalongthewallofthecombustor.Theresultsshowthat:(1)thiscontinuum-trajectorymodelwithreactingparticlephasecanbeusedinpracticalengineeringtoqualitativelypredicttheflamestability,concentrationsofgasspecies,possibilitiesofslagformationandsootdeposition,etc.;(2)largerecirculationzonescanbecreatedinthecombustor,whichisfavorabletotheignitionandflamestabilization.
简介:AlaminarpremixedPropane/Airflamewithafuelequivalenceratioof2.1wasemployedforanalysisofsootparticles.Zeroth-orderIognormaldistributions(ZOLD)wereusedintheanalysisofexperimentaldistributionphenomenaatdifferentresidencetimesduringsootformationintheflame.Rayleigh'stheoryandMie'sscatteringtheorywerecombinedwithagglomerateanalysisusingscatteringandextinctiondatatodeterminethefollowingsootcharacteristics:agglomerateparameters,volumetricfractions,massflowratesandsurfacegrowthrate.Sootdensitymeasurementswerecarriedouttodeterminedensityvariationsatdifferentstagesofgrowth.Themeasuredresultsshowthatmetricfractionandmassflowrateindicatethatthesurfacegrowthrateofsootparticlesexceedstheoxidationratesintheflamestudied.Thedataobtainedinthisworkwouldbeusedtostudysootoxidationrateunderflamingcondition.
简介:3-DevolutionofKarmanvortexfilamentsandvortexfilamentsinbraidregionsintheturbulentwakeofa2-Dcirculaxcylinderisinvestigatednumeri-callybasedoninviscidvortexdynamicsbyanalyzingtheresponseoftheinitially2-Dspanwisevortexfilamentstoperiodicspanwisedisturbanceofvaryingmagnitude,wavelengthandinitialphaseangles.Ourresultsrevealakindof3-Dvortexsysteminthewakewhichconsistsoflargescalehorseshoe-shapedvorticesandsmallscaleλ-shapedvortexfilamentsaswellasvortexloops.Themechanismandthedynamicprocessaboutthegenerationofstreamwisevorticalstructureandthe3-Dcoherentstructurearereported.
简介:Fortwo-dimensionnonlinearconvectiondiffusionequation,atwo-gridmethodofcharacteristicsfinite-elementsolutionwasconstructed.Inthismethodthenonlineariterationsisonlytoexecuteonthecoarsegridandthefine-gridsolutioncanbeobtainedinasinglelinearstep.Forthenonlinearconvection-dominateddiffusionequation,thismethodcannotonlystabilizethenumericaloscillationbutalsoacceleratetheconvergenceandimprovethecomputationalefficiency.Theerroranalysisdemonstratesifthemeshsizesbetweencoarse-gridandfine-gridsatisfythecertainrelationship,thetwo-gridsolutionandthecharacteristicsfinite-elementsolutionhavethesameorderofaccuracy.Thenumericalexampleconfirmsthatthetwo-gridmethodismoreefficientthanthatofcharacteristicsfinite-elementmethod.