简介:Thinfilmsofpolymerblendscomposedofalternatingcopolymer,diblockcopolymerand/orhomopolymerarestudiedusingMonteCarlosimulation.Amultilayermorphologyisobservedinthefilm,thatis,theblendedpolymersassembleintoindividualdomainsarrangedfrominteriortothesurfacesofthefilm.Thecoexistingcomponentsresidingthroughouttheneighboringdomainsinthefilmmakenodistinguishableinterfacebetweenanyneighboringdomains.Bythismeans,itformsaverticalcompositiongradientinthepolymericfilm.Beingdifferentfromlayer-by-layerdepositionofpolyelectrolyteorhydrogenbondingapproachetc.,thelayeredstructureinthisstudyisformedbypolymerblendinginonestep.Alternatingcopolymersarefoundtobeessentialcomponentstoformverticalcompositiongradient(layeredstructure)inthinfilms.
简介:StdHepC++[1]isaCLHEP[2]MonteCarloeventclasslibrarywhichprovidesacommoninterfacetoMonteCarloEventGenerators,ThisworkisanextensiveredesignoftheStdHepFortraninterfacetousethefullpowerofobjectorienteddesign,AgeneratedeventmapsnaturallyontotheDirectedAcyclicGraphconceptandwehaveusedtheHepMCclassestoimplementthis.Thefullimplementationallowstheusertocombineeventstosimulatebeampileupandaccessthemtransparentlyasthoughtheywereasingleevent.
简介:Basedonthepreparativeexperimentsofthelight-emittingdiode(LED)encapsulant,threetypesofmonomermodelswithdifferentfunctionalgroupsarecarriedouttostudythepolymerizationprocessbydynamicMonteCarlo(DMC)simulationandbondfluctuationmodel(BFM).Wecalculatethedegreeofpolymerization,theradiusofgyrationandthefrequencyofvoidspherestodiscussthepolymerizationprocess,themolecularsizeandthespatialdistributionatdifferentvolumefractionsandproportions.OurresultsareinagreementwithGrest'sdecayrateandFlory'sscalelaw.Simulationsshowthatthepolymerizationprocessdependsontheappropriatevolumefractionandproportionexceedingly,andthevolumecontractioninthepolymerizationprocesscanalsobeobservedinthisstudy.Theseinvestigationscouldprovidesomeinsightsintotheunderstandingofthepolymerizationprocessoftheencapsulantandhelpustoadjusttheparametersinlaterexperiments.
简介:TheMonte-CarloArrayProcessor(MAP)hasbeendesignedusingcommodityofftheshelf(COTS)itemstoprovidetheCPUrequirementsoffulleventsimulationfortheLHCexperiments.Thesolutionishowevercompletelygeneral,soandCPUintensiveapplicationwithlimitedinputrequirementscanberunonthesystem.Operatingcontrolsoftwarehasbeenwrittentomanagethedataflowoiverthe100BaseTethernetconnectingthe300nodes(400MHzPII's)tothe6mastercontrolnodes700MHzPIII'seachwith500Gbofdisk),Upgradeto1000nodesisplkanned.Jobcontrolsoftwarethatallowstheusertorunthesamejobonallnodes,whilstallowingforsmalldifferencesininitialisationparametersbetweennodeshasalsobeenwritten.GMAPistheGRIDawareMAPcontrolsoftware,Thisallowsremotejobpreparationandsubmissionusingglobustoolkitforauthentificationandcommunication.ThesoftwarewillbeavailableandopensthepossibilityfordoingmassiveMonteCarloproductionoverseveralremoteMAPsitessimultaneously.
简介:ThefundamentalelemetsoftheLHCbMonteCarloproductionsystemaredescribed,coveringsecurity,Jobsubmission,execution,datahandlingandbookkeeping,AnanalysisisgivenofthemainrequirementsforGRIDfacilities,togetherwithsomediscussionastohowtheGRIDcanenhancethissystem.AsummaryisgivenofthefirstexperiencesinmovingthesystemtoaGRIDenvironment.ThefirstplanningforinterfacingtheLHCbOOframeworktoGRIDservicesisoutlined.
简介:Thispaperintroducestwokindsofmethodswithhighaccuracyforfi-niteelementprobabilitycomputingmethod,bywhichthefunctionvalueononeorafewnodescanbecalculatedwithoutformingthetotalstiffnessmatrix.
简介:Reconstructionofabsorptioncoefficientμ_aandscatteringcoefficientμ_aisveryimportantforapplicationsofdiffuseopticaltomographyandnearinfraredspectroscopy.Aimingattheearlycancerdetectionofcervixandstomach,wepresentafastinverseMonte-Carloschemeforextractingμ_aandμ_sofatubulartissuefromthemeasurementonfrequencydomain.Resultsshowthatthecomputationtimeforreconstructingonesetofμ_aandμ_sislessthan1minandtherelativeerrorsinreconstructionarelessthan±10%fortheopticalpropertiesofnormalcervicaltissueandprecancerouslesions.
简介:Thestochasticmodelsoftheusualjointsarefirstestablishedthroughintro-ducingtheconceptsof“clearancecharacteristicelement”and“clearancespace”.Afterde-rivingtheprobabilitydensityfunctionofthejointclearanceandmakingtheprobabilisticanalysisoftheresultedkinematicerrors,thesamplingformulasoftheindependentvaria-blesofthejointclearancesarefurtherdeduced.ThroughMonteCarlosimulation,thesta-tisticalcharacteristicsandfrequencyhistogramsofthekinematicerrorsarethenanalysedoncomputer.
简介:Inthispaperweproposedanovelexactfixed-nodequantumMonteCarlo(EFNQMC)algorithm,whichisaself-optimizingandself-improvingprocedure,IncontrasttothepreviousEFNQMCmethod,thetrialfunctionisoptimizedsynchronisticallyinthediffusionprocedure,butnotbeforethebeginningofEFNQMCcomputation.Inordertooptimizethetrialfunction,theimprovedsteepestdescenttechniqueisused,inwhichthestepsizeisautomaticallyadjustable.Theprocedureisquasi-Newtonandconvergessuperlinearly.Wealsouseanoveltrialfunction,whichhascorrectelectron-electronandelectron-nucleuscuspconditions.ThenovelEFNQMCalgorithmandthenoveltrialfunctionareemployedtocalculatetheenergiesof1^1A1stateofCH2,^1AgstateofC8andtheground-statesofH2,LiH,Li2,H2O,respectively.Thetestresultsshowthatboththenovelalgorithmandthetrialfunctionproposedinthepresentpaperareveryexcellent.
简介:对核参数敏感度和不确定性分析的理论方法进行了探讨,在敏感度系数的基础上所定义的积分指标Esum能定量地表示出两个不同核裂变装置的相似性,即可用于定量地比较一个基准核裂变实验装置与一个欲评估核裂变装置的相似程度。不确定性的分析提供了一个计算核裂变系统中由于截面数据方差而导致系统中七疆方差的方法,并且也提供了一个计算不同核裂变系统中Keff协方差的方法。不确定性的分析方法是将截面数据的方差信息通过与能量有关的敏感度系数传播给Keff行。某一材料截面数据的方差可以传播给所有含有该材料的临界装置。有着相同材料的临界装置将产生关联。
简介:摘要:阐述了Monte Carlo法在装配尺寸链公差设计中的应用原理,以北京19号线地铁项目的罩板装配为研究对象,横罩板和立罩板之间的罩板间隙为优化目标,通过分析工艺流程中装配误差的类型和原因,在MATLAB中进行模拟计算。在增加尺寸链数据与高斯分布函数拟合次数后,可以减少尺寸链中零部件公差范围,从而有效降低制造难度和节约加工成本。在轨道车辆内装设计过程中使用Monte Carlo法辅助计算,是一种合理分配尺寸链公差,避免装配误差累积的优化方法。