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简介：Thispaperstudiesrestrictedfaultdiameterofthen-dimensionalhypercubenetworksQn(n≥2).ItisshownthatforarbitrarytwoverticesxandywiththedistancedinQnandanysetFwithatmost2n-3verticesinQn-{x,y},ifFcontainsneitherofneighbor-setsofxandyinQn,thenthedistancebetweenxandyinQn-FisgivenbyD(Qn-F；x,y){=1,for=1；≤d+4,for2≤d≤n-2,n≥4；≤n+1,ford=n-1,n≥3；=n,ford=n.Furthermore,theupperboundsaretight.Asanimmediatelyconsequence,Qncantolerateupto2n-3verticesfailuresandremaindiameter4ifn=3andn+2ifn≥4providedthatforeachvertexxinQn,alltheneighborsofxdonotfailatthesametime.ThisimprovesEsfahanian'sresult.

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简介：LetG=(V,E)beaconnectedgraphandmbeapositiveinteger,theconditionaledgeconnectivityλδmistheminimumcardinalityofasetofedges,ifitexists,whosedeletiondisconnectsGandleaveseachremainingcomponentwithminimumdegreeδnolessthanm.Thisstudyshowsthatλδ1(Qn,k)=2n,λδ2(Qn,k)=4n-4(2≤k≤n-1,n≥3)forn-dimensionalenhancedhypercubeQn,k.Meanwhile,anothereasyproofaboutλδ2(Qn)=4n-8,forn≥3isproposed.Theresultsofenhancedhypercubeincludethecasesoffoldedhypercube.

简介：Inthispaper,wefocusonthevertex-fault-tolerantcyclesembeddingonenhancedhypercube,whichisanattractivevariantofhypercubeandisobtainedbyaddingsomecomplementaryedgesfromhypercube.LetFvbethesetoffaultyverticesinthen-dimensionalenhancedhypercubeQn,k（1≤k≤n-1）.When|Fv|=2,weshowedthatQn,k-Fvcontainsafault-freecycleofeveryevenlengthfrom4to2n-4wheren（n≥3）andfchavethesameparity;andcontainsafault-freecycleofeveryevenlengthfrom4to2n-4,simultaneously,containsacycleofeveryoddlengthfromn—fc+2to2n-3wheren（≥3）andfchavethedifferentparity.Furthermore,when|Fv|=fv≤n-2,weproofthatthereexiststhelongestfault-freecycle,whichisofevenlength2n-2fvwhethern（n>3）andfehavethesameparityornot;andthereexiststhelongestfault-freecycle,whichisofoddlength2n-2fv-1inQn,k—Fvwheren（≥3）andfchavethedifferentparity.

简介：Inthispaper,theproblemoffault-tolerantroutingsinfault-tolerantnetworksisconsidered.Aroutinginanetworkassignstoeachorderedpairofnodesafixedpath.Allcommunicationamongnodesmustgoonthisrouting.Wheneitheranodeoralinkinafault-tolerantnetwork{ails,thecommunicationfromonenodetoanotherusingthisfaultyelementmustbesentviaoneormoreintermediatenodesalongasequenceofpathsdeterminedbythisrouting.Animportantandpracticalproblemishowtochoosearoutinginthenetworksuchthatintermediatenodestoensurecommunicationaresmallforanyfault-set,LetCdbeadirectedcycleoforderd.Inthispaper.Theauthor{irstdiscussesconnectivityofCartesianproductdigraphs,thenprovesthattheCartesianproductdigraphCd1×Cd2×…×Cdn(di≥2,1≤i≤n)hasaroutingsuchthatatmostoneintermediatenodeisneededtoensuretransmissionofmessagesamongallnon-faultynodessolongasthenumberoffaultsislessthann,ThisisageneralizationofDolevetal'sresultforthen-dimensionalcuhe.

简介：教育研究常常遇到抽样的问题,而我们阐述较多的是如何使用随机抽样以保证教育研究的科学性.对使用较多的有目的抽样则阐述较少.本文以随机抽样的局限性为引子,集中对教育科研中有目的抽样的含义、变式、以及如何应用做了初步的探讨,以期引起研究者的重视.

简介：抽样调查是一种很重要的统计非全面调查方法，它在实际中应用很广。而系统抽样和分层抽样作为两种完全不同的抽样调查组织形式，因为二者有相似之处，在实际工作中常常被混为一谈，有人甚至用分层抽样的误差公式代替系统抽样的误差公式，其结果导致了调查误差的增大。本文从二者定义出发，对这两种抽样调查组织形式进行了分析，并通过实例证明了二者存在着实质性差别，并对系统样本的抽样方差与分层样本的抽样方差之联系进行了分析和探讨

简介：分层抽样与分群抽样之比较文＼杭州商学院　胡聪进行抽样调查有多种形式，分层抽样与分群抽样则是其中应用较为广泛的两种。本文从两方面将二者作一比较．（一）分层抽样与分群抽样组织形式的比较分层抽样是先将总体按其主要标志加以分组，后再从各组中按随机原则抽选一定...

简介：统计的基本思想方法是用样本估计总体，即用局部估计整体，这就要求样本应具有很好的代表性，而样本的良好客观的代表性，则完全依赖于抽样方法。

简介：ThedesignofnewSatelliteLaunchVehicle(SLV)isofinterest,especiallywhenacombinationofSolidandLiquidPropulsionisincluded.ProposedisaconceptualdesignandoptimizationtechniqueformultistageLowEarthOrbit(LEO)boundSLVcomprisingofsolidandliquidstageswiththeuseofGeneticAlgorithm(GA)asglobaloptimizer.ConvergenceofGAisimprovedbyintroducinginitialpopulationbasedontheDesignofExperiments(DOE)Technique.LatinHypercubeSampling(LHS)-DOEisusedforitsgoodspacefillingproperties.LHSisastratifiedrandomprocedurethatprovidesanefficientwayofsamplingvariablesfromtheirmultivariatedistributions.InSLVdesignminimumGrossLiftoffWeight(GLOW)conceptistraditionallybeingsought.SincethedevelopmentcoststendtovaryasafunctionofGLOW,thisminimumGLOWisconsideredasaminimumdevelopmentcostconcept.Thedesignapproachismeaningfultoinitialdesignsizingpurposeforitscomputationalefficiencygivesaquickinsightintothevehicleperformancepriortodetaileddesign.

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简介：〔摘要〕用新课标理念中的发展学生的数学应用意识来指导教学。学生已学习了随机抽样的方法，在此基础上结合具体问题情境，进行抽样调查，突出统计在日常生活中的应用。达到了巩固运用的目的，达到了学习的终极目标。

简介：Comparedwithaccuratediagnosis,thesystem’sselfdiagnosingcapabilitycanbegreatlyincreasedthroughthet/kdiagnosisstrategyatmostkvertexestobemistakenlyidentifiedasfaultyunderthecomparisonmodel,wherekistypicallyasmallnumber.BasedonthePreparata,Metze,andChien(PMC)model,then-dimensionalhypercubenetworkisprovedtobet/kdiagnosable.Inthispaper,basedontheMaengandMalek(MM)?model,anovelt/k-faultdiagnosis(1k4)algorithmofndimensionalhypercube,calledt/k-MM?-DIAG,isproposedtoisolateallfaultyprocessorswithinthesetofnodes,amongwhichthenumberoffault-freenodesidentifiedwronglyasfaultyisatmostk.ThetimecomplexityinouralgorithmisonlyO(2nn2).

简介：统计分析需要收集数据，但收集全部数据有时很梭，有时处理数据的工作量太大，如人口普查，民间测验等，收集数据有时具有破坏性，

简介：目录抽样技术浅析文／陕西财经学院王云亮统计体系改革的一个重要方面就是调查方法体系的改革。它是保证以较少的成本、费用获得高质量的统计信息的重要手段。１９９４年２月召开的全国统计工作会议明确提出了统计调查方法改革的目标模式。即“建立一个以必要的周期性普查...

简介：以往,学生要进行竞赛,总是层层筛选,因而竞赛永远展现的只是那些"姣姣者"的"风采",从来没有后进生表现的"舞台",因此那些学习差的同学也懒得去理睬.且不论竞赛的结果,单单是被选拔为"代表"就足以使这些"骄子"们引以为自豪了!这使我突然受到启发;何不让后进生也"风光"一回、"飘飘然"一下呢?这不也正体现了教育的平等性吗?于是在一次全校初一年级的数学竞赛中,我开始尝试这种方法.