简介:LetXbeaweaklyCauchynormedspaceinwhichtheparallelogramlawholds,CbeaboundedclosedconvexsubsetofXwithonecontractingpointandTbean{a,b,c}-generalized-nonexpansivemappingfromCintoC.Weprovethattheinfimumoftheset{||x-T(x)||}onCiszero,studysomefactsconcerningthe{a,b,c}-generalized-nonexpansivemappingandprovethattheasymptoticcenterofanyboundedsequencewithrespecttoCissingleton.Dependingonthefactthatthe{a,b,0}-generalized-nonexpansivemappingfromCintoChasfixedpoints,accordingly,anotherversionoftheBrowder’sstrongconvergencetheoremformappingsisgiven.
简介:Inthispaper,least-squaxesmirrorsymmetricsolutionformatrixequations(AX=B,XC=D)anditsoptimalapproximationisconsidered.Withspecialexpressionofmirrorsymmetricmatrices,ageneralrepresentationofsolutionfortheleast-squaresproblemisobtained.Inaddition,theoptimalapproximatesolutionandsomealgorithmstoobtaintheoptimalapproximationareprovided.
简介:TheexistenceanduniquenessofclassicalglobalsolutionstoatypeofBoussinesqequationswithinitialandboundaryvaluesarestudiedinthispaper.TheexistenceofsuchsolutionsisprovedbymeansofcompactnesstheoremandSchaudersfixedpointtheorem,anditsuniquenessbythesocalledenergymethod.
简介:一、填空(1~5小题各3分,6~8小题各4分,9、10小题各5分,共37分)1.三角形的内角和是,一个外角等于的两个内角的和.2.等腰三角形的周长是40cm,腰是底的2倍,则底边长cm.3.△ABC的三个内角满足∠C=∠A-∠B,则△ABC是三角形.4.如图A-14,∠A+∠B+∠C+∠D+∠E+∠F=.图A-14图A-155.如图A-15,AD是等腰Rt△ABC的角平分线,DE⊥AB于E.若CD=5cm,则BE=cm.6.等腰三角形的底角等于15°,腰的长20cm,则腰上的高是cm.7.等边三角形的边长是4cm,则它的面积是cm2.8.如图A-16,△ABC中,AB=AC,∠A=30°,BD
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简介:ManyworkshaveinvestigatedtheproblemofreparameterizingrationalBéziercurvesorsurfacesviaMbiustransformationtoadjusttheirparametricdistributionaswellasweights,suchthatthemaximalratioofweightsbecomessmallerthatsomealgebraicandcomputationalpropertiesofthecurvesorsurfacescanbeimprovedinaway.However,itisanindicationofveracityandoptimizationofthereparameterizationtodopriortojudgewhetherthemaximalratioofweightsreachesminimum,andverifythenewweightsafterMbiustransformation.What’smoretheusersofcomputeraideddesignsoftwaresmayrequiresomeguidelinesfordesigningrationalBéziercurvesorsurfaceswiththesmallestratioofweights.Inthispaperwepresentthenecessaryandsufficientconditionsthatthemaximalratioofweightsofthecurvesorsurfacesreachesminimumandalsodescribeitbyusingweightssuccinctlyandstraightway.Theweightsbeingsatisfiedtheseconditionsarecalledbeinginthestablestate.Applyingsuchconditions,anygivingrationalBéziercurveorsurfacecanautomaticallybeadjustedtocomeintothestablestatebyCADsystem,thatis,thecurveorsurfacepossessesitsoptimalparametricdistribution.Finally,wegivesomenumericalexamplesfordemonstratingourresultsinimportantapplicationsofjudgingthestablestateofweightsofthecurvesorsurfacesanddesigningrationalBéziersurfaceswithcompactderivativebounds.
简介:文[1]中提出了求解连续函数f(x)总体极小值的均值算法,并证明了算法的全局收敛性.若假设f(x)是定义在某可测集G上的可测函数,本文证明了均值算法产生的迭代序列全局收敛到f(x)的本质极小值,若进一步假设函数f(x)满足测度Lipschitz条件,还证明了求可测函数的均值算法是线性收敛的.
简介:在求块Toeplitz矩阵束(Amn,Bmn)特征值的Lanczos过程中,通过对移位块Toepltz矩阵Amn-ρBmn进行基于sine变换的块预处理,从而改进了位移块Toeplitz矩阵的谱分布,加速了Lanczos过程的收敛速度.该块预处理方法能通过快速算法有效快速执行.本文证明了预处理后Lanczos过程收敛迅速,并通过实验证明该算法求解大规模矩阵问题尤其有效.