简介:AfluidbuffermodelwithMarkovmodulatedinput-outputratesisconsidered.Whentrafficintensityisnearitscriticalvalue,thesystemisknownasinheavytraffic.Itisshownthatasuitablyscaledsequenceoftheequilibriumbuffercontentshasaweakordistributionallimitunderheavytrafficconditions.ThisweaklimitisafunctionalofadiffusionprocessdeterminedbytheMarkovchainmodulatingtheinputandoutputrates.Thefirstpassagetimeofthereflectedprocessisexamined.ItisshownthatthemeanfirstpassagetimecanbeobtainedviaasolutionofaDirichletproblem.ThenthetransitiondensityofthereflectedprocessisderivedbysolvingtheKolmogorovforwardequationwithaNeumannboundarycondition.Furthermore,whenthefastchangingpartofthegeneratoroftheMarkovchainisaconstantmatrix,therepresentationoftheprobabilitydistributionofthereflectedprocessisderived.Upperandlowerboundsoftheprobabilitydistributionarealsoobtainedbymeansofasymptoticexpansionsofstandardnormaldistribution.
简介:多重消息拷贝保证消息交货的在容忍的网络通常利用的延期的路由协议,以便克服无法预言的节点活动性和容易打断的连接。一个store-carry-and-forward范例也被建议进一步改进消息交货。然而,过多的消息拷贝导致缓冲区和带宽的缺乏。水花并且等待路由协议被建议了减少不受限制的消息拷贝的缓冲区和传播引起的网络超载。然而,当一个节点缓冲区相当被抑制时,仍然在那里存在拥挤问题。在这份报纸,我们在水花上建议安排的一条消息和落下策略并且等待路由协议(SDSRP)。为了改进交货比率,首先,SDSRP由评估在交货比率上复制并且落下一个消息拷贝的影响计算每条消息的优先级。随后,安排并且落下决定根据优先级被做。为了推进,增加交货比率,我们在水花上建议安排的一条改进消息和落下策略并且通过提高估计参数的精确性等待路由协议(ISDSRP)。最后,我们在一个基于合成、真实的踪迹进行广泛的模拟。结果证明与另外的缓冲区管理策略相比,ISDSRP和SDSRP完成更高的交货比率,类似的平均hopcounts,和更低的架空的比率。
简介:TheUnitedStatesDepartmentofAgriculture(USDA)AnnualizedAgriculturalNon-PointSourcePollutionmodel(AnnAGNPS)isusedtohelpevaluateawatershedresponsetoagriculturalmanagementpracticestocontrolwaterquality.However,AnnAGNPSversion3.5doesnotcontainfeaturestoestimatetheeffectofariparianbuffer(RB)systemonwaterquality.TheRiparianEcosystemManagementModel(REMM)isusedtosimulatetheimpactofriparianbuffersystemsonwaterquality.However,frequentlythelackofmeasureduplandloadingsthatarerequiredbyREMMsimulationlimitstheapplicationofREMM.Toaddressthisdatagap,astudywasconductedtointegrateAnnAGNPSwithREMMforRBsystemsimulation.AnnAGNPSwasusedtosimulatewaterandsedimentloadingsfromanuplandfieldintoathree-zoneRBsystemattheGibbsFarmlocatedintheGeorgiacoastalplain.TheseAnnAGNPSoutputswereusedastheinputstoREMM.REMMwasusedtosimulatewaterandsedimentmovementalongtheriparianbuffers.TheAnnAGNPSsimulatedamountofannualrunoffattheedgeofthefieldwasclosetoobservedamounts(Nash-Sutcliffeefficiencyof0.92).Itisbelievedthatasubstantialportionofsandwasremovedfromtherunoffonemeterintothegrassbufferwherethesamplerswerelocated;therefore,sandwasexcludedfromtheAnnAGNPSsimulationforcomparisonwithobservedsediment.Excludingsand,theAnnAGNPSpredictedamountofannualsedimentmatchestheobservedamountfairlywell(Nash-Sutcliffeefficiencyof0.46).Inaddition,basedonevaluatingthepercentreductionofsedimentateachzonalinterface,theAnnAGNPS/REMMmodelwellsimulatedthefunctionoftheRBsystemtoreducesediment.
简介:MgO薄电影被激光脱离在各种各样的底层温度(T潜水艇)下面在Si(100)底层上扔,期望提供为Si底层上的功能的perovskite氧化物电影的粗糙的生长的候选人缓冲区层。比较喜欢的取向,crystallinity和这些电影的表面形态学上的T潜水艇的效果被调查。MgO电影在单相在473973K被获得。与增加T潜水艇,这些电影的比较喜欢的取向变化了从(200)到(111)。crystallinity和表面形态学也是不同的,依靠T潜水艇。在Tsub=673K,MgO电影变得一致、光滑,展出高crystallinity和一块稠密的质地。
简介:Two-stepgrowthregimeswereappliedtorealizeahomoepitaxialgrowthofZnOfilmsonfreestandingdiamondsubstratesbyradio-frequency(RF)reactivemagnetronsputteringmethod.ZnObuerlayersweredepositedonfreestandingdiamondsubstratesatalowsputteringpowerof50W,andthenZnOmainlayerswerepreparedonthisbufferlayeratahighsputteringpowerof150W.Forcomparison,asamplewasalsodepositeddirectlyonfreestandingdiamondsubstrateatapowerof150W.TheeffectsofZnObufferlayersonthestructural,optical,electricalandmorphologicalpropertiesoftheZnOmainlayerwerestudiedbyX-raydiffraction(XRD),scanningelectronmicroscopy(SEM),Ramanspectroscopy,semiconductorcharacterizationsystemandatomicforcemicroscopy(AFM)respectively.Theexperimentalresultssuggestedthathomo-bufferlayerwashelpfultoimprovethecrystallinequalityofZnO/diamondheteroepitaxialfilms.