简介:让一,b,k,r是有1一b和r的nonnegative整数2。让G是有$n的顺序n的一张图>\tfrac{{(+b)(r(+b)-2)+ak}}{一}$。在这份报纸,我们首先为部分的所有显示出描述(一,b,k)批评的图。然后使用结果,我们证明G都是部分的(一,b,k)批评如果$\delta(G)\geqslant\tfrac{{(r-1)b^2}}{一}+k$并且$|N_G(x_1)\cupN_G(x_2)\cup\cdots\cupN_G(x_r)|\geqslant\tfrac{{bn+ak}}{{+b}}$为任何独立子集{x1,x2,,xr}在G。而且,这被显示出条件$|N_G(x_1)上的更低的界限\cupN_G(x_2)\cup\cdots\cupN_G(x_r)|\geqslant\tfrac{{bn+ak}}{{+b}}$是在某感觉可能的最好,并且它是Lus的延期以前的结果。
简介:CRITICALSTOPPINGTIMESANDSEMIMARTINGALESOFSTOCHASTICPROCESSESHuBijin(胡必锦)(DepartmentofMathematicsHUSTWuhan,HubeiP.R.C.3.1992)A...
简介:Themostsignificantdifferencesbetweencontinuousweldedrails(CWRs)andgeneralsplit-typeconnectorsareaxialcompressioninthelongitudinaldirection,bucklingstabilityandotherissuesgeneratedundertheinfluenceofthermaleffect.Underthermaleffect,adynamicalbehaviorsimilartothatofabeamfixedontwosidesoccursinthecentrallockedareaoftheweldedrail,asthereisaxialcompressionbutnopossibilityofsliding.Continuousweldedrailsdonotcontractorexpand,andaresupportedbythedynamicalsystemmadeupofballastsandrailclips.Therail-supportsystemmentionedabovehasthefeaturesofnon-uniformmaterialdistributionanduncertaintyofconstructionquality.Duetothesefacts,thedynamicsmethodbasedonthelinearelastichypothesiscannotcorrectlyevaluatetherail'sbucklingconditions.ThisstudyisaimedatapplyingFiniteDifferenceMethod(FDM)andMonteCarloRandomNormalVariablesMethodtotheanalysisofweldedrail'sbucklingbehaviorduringthetrain'saccelerationanddeceleration,underthermaleffectanduncertainfactorsofballastandrailclips.Theanalysisresultshowedthatbucklingoccursunderthecombinedeffectofthermaleffectandthetrain'sdecelerationforceco-effectandthevarianceratioofballastandrailclipsisover0.85,orunderthecombinedeffectofthermaleffectandthetrain'saccelerationforcewhenthevarianceratioisover0.88.
简介:Inthispaper,westudythelocalbifurcationofcriticalperiodsnearthenondegeneratecenter(theorigin)ofaclassofLiénardequationswithdegree2n,andprovethatatmost2n-2criticalperiods(takenintoaccountmultiplicity)canbeproducedfromaweakcenteroffiniteorder.Wealsoprovethatitcanhaveexactly2n-2criticalperiodsneartheorigin.
简介:Thispaperisconcernedwiththeharmonicequation(P_(■ε)):?u=0,u>0inB~nand?u/?ν+((n-2)/2)u=((n-2)/2)Ku~(n/(n-2)■ε)onS~(n-1)whereB~nistheunitballinR~n,n≥4withEuclideanmetricg_0,?B~n=S~(n-1)isitsboundary,KisafunctiononS~(n-1)andεisasmallpositiveparameter.Weconstructsolutionsofthesubcriticalequation(P_(-ε))whichblowupatonecriticalpointofK.WegivealsoasufficientconditiononthefunctionKtoensurethenonexistenceofsolutionsfor(P_(-ε))whichblowupatonepoint.Finally,weproveanonexistenceresultofsinglepeakedsolutionsforthesupercriticalequation(P_(+ε)).
简介:Firstly,thispaperreviewsHall'stheoryofbootstrapcriticalpoints(Hall,1988)andtheEdgeworthexpansionforthemetrodirectionσ=μ(Fn)ofdirectionaldata(Wu&Deng,1996),andthenappliesHall'sresultstostudysixbootstrapconfidenceintervalsforcircularmeandirectionμ=μ(F).OurresultsshowthatSTUD-intervalandABC-intervalarebothsecond-ordercorrect.ForyonMisespopudationM(μ,k),wefindthatsixbootstrapconfidenceintervalsaxeseeond-ordercorrectliketheapproximatenormalconfidenceinterval,andSTUD-intervalisthird-ordercorrect.
简介:让G是2是的一张图,和k一个积极整数。图G是部分independentset-deletablek-factor-critical(简言之,部分ID-k-factor-critical),如果官方补给为每个独立人士的部分k因素设定我G。有约束力的数字绑图G的(G)被定义为$$bind(G)=min\left\{{\frac{{\left|{N_G(X)}\right|}}{{\left|X\right|}}:\not0\neX\subseteqV(G),N_G(X)\neV(G)}\right\}在这份报纸的.$$,如果,图G是部分ID-k-factor-critical,这被证明如果n6k9并且绑(G)$>\frac{{(3k-1)(n-1)}}{{kn-2k+2}}$。