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简介:1.IntroductionRecently,singleserverqueueswithvacationshavebeenstudiedextensivelyfromtheirowntheoreticalinterestaswellastheirapplicationstomanyengineeringsystemssuchascomputers,communicationnetworksandmanufacturingsystems.FOrtheM/G/lqueueingsystemswit...
简介:Inthispaper,asteady-stateMarkovianmulti-serverretrialqueueingsystemwithBernoullivacationschedulingserviceisstudied.Usingmatrix-geometricapproach,variousinterestingandimportantsystemperformancemeasuresareobtained.Further,theprobabilitydescriptorslikeidealretrialandvainretrialareprovided.Finally,extensivenumericalillustrationsarepresentedtoindicatethequantifyingnatureoftheapproachtoobtainsolutionstothisqueueingsystem.
简介:为了解决M/M/c模型在实际运用中模拟精度不高及使用范围有限的问题,本文立足系统状态变化与输入率和服务率的关系,通过引入输入概率和服务度,构建依赖系统状态的递进式输入率和服务率。递进式输入率和服务率通过研究系统实际运行状况设定临界值,其中输入率分为两阶段,服务率分为三阶段。此外,结合递进式输入率和服务率及排队论状态转移过程构建了递进式M/M/c模型,并采用后确定法确定模型参数。递进式M/M/c模型是M/M/c模型的扩展形式,提高了M/M/e模型的模拟精度,在一定程度上拓展了模型的应用范围。最后,通过一个生活实例验证了递进式M/M/c模型的优化性和实用性。
简介:A.simplicialmesh(triangulation)isconstructedthatgeneralizesthetwo-dimensional4-directionmeshtoR~m.Thismesh,withsymmetric,shift-invariantvaluesatthevertices,isshowntoadmitaboundedC~1interpolantifandonlyifthealternatingsumofthevaluesattheverticesofany1-cubeiszero.Thisim-pliesthaiinterpolationattheverticesofanm-dimensional,simplicialmeshbyaC~1piecewisepolynomialofdegreem+1withonepiecepersimplexisunstable.
简介:Inthispaper,MPt/C(M=La,Nd)catalystsofPEMFCweresynthesizedbymicrowaveradiationprocess.ThecrystallinityandstructureofcatalystswererespectivelyanalyzedbyXRDandnitrogenadsorptiontests.Theactivityofcatalystswasinvestigatedbyelectrochemistryexperiment.Theresultsshowedthat:1)comparedwithPt/Ccatalystpreparedbytypicalimpregnation-reductionprocess,thesizeofMPt/CcatalystparticledecreasedandtheavailablecrystalforO2reductionincreased;2)theMPt/CcatalystshadrelativelyhighBETsurfaceareas;and3)thesecrystaltransformationsoftheMPt/Ccatalystbroughthightheelectrocatalyticactivity,andasaresult,improvedthepowerofPEMFC.