简介:介绍了2014年美国大学生数学建模竞赛C题的背景与立意,针对6篇获得Outstanding奖的论文的解题思路与方法进行了归纳与总结,指出了学生答卷中的亮点与不足,并给出了建议和改进方案。
简介:上海市社会总抚养比受到诸多因素的影响,导致数据波动性较大,单纯地采用灰色预测模型无法更加准确地进行预测,因此文章提出了基于最小二乘法的改进GM(1,1)模型.首先文章介绍了普通GM(1,1)模型的建立方法与步骤;接着通过采用最小二乘法的原理弱化波动较大的数据,加强其规律性从而建立新的GM(1,1)模型;最后结合2007-2011年上海市社会总抚养比数据建立新的预测模型,并用2012年数据对模型进行验证合格,可以用来预测未来几年上海市社会总抚养比,便于该市对未来经济的发展宏观调控.结果表明该预测方法是合理可行的,为其他相关预测提供了理论依据.
简介:研究具有任意常半径r的切球丛,得到该切球丛是Einstein的一个充分必要条件。
简介:Inthispaper,theauthorsobtaintheBaecklundtransformationontime-likesurfaceswithconstantmeancurvatureinR^2,1.Usingthistransformation,familiesofsurfaceswithconstantmeancurvaturefromknownonescanbeconstructed.
简介:Therearemanyacceleratingconvergencefactors(ACFs)forlimitperiodiccontinuedfractionK(an/1)(an→a≠0).Inthispaper,somecharacteristicsandcomparativetheoremsareobtainedonACFs.TworesultsaregivenformostfrequentlyusedACFs.
简介:Inthispaper,theL1-normestimatorsandtherandomweightedstatisticforasemiparametricregressionmodelareconstructed,thestrongconvergenceratesofestimatorsareobtainundercertainconditions,thestrongefficiencyoftherandomweightingmethodisshown.AsimulationstudyisconductedtocomparetheL1-normestimatorwiththeleastsquareestimatorintermofapproximateaccuracy,andsimulationresultsaregivenforcomparisonbetweentherandomweightingmethodandnormalapproximationmethod.
简介:Inthispaperwewillshowthatifanapproximationprocess{Ln}n∈Nisshapepreservingrelativetotheconeofallk-timesdifferentiablefunctionswithnon-negativek-thderivativeon[0,1],andtheoperatorsLnareassumedtobeoffiniterankn,thentheorderofconvergenceofDkLnftoDkfcannotbebetterthann2evenforthefunctionsxk,xk+1,xk+2onanysubsetof[0,1]withpositivemeasure.Takingintoaccountthisfact,wewillbeabletofindsomeasymptoticestimatesoflinearrelativen-widthofsetsofdifferentiablefunctionsinthespaceLp[0,1],p∈N.
简介:<正>LetD={z∈:|z|<1}andφbeanormalfunctionon[0,1).Forp∈(0,1)suchafunctionφisusedtodefineaBergmanspaceA~p(φ)onDwithweightφ~p(|·|)/(1-|·|~2).Inthispaper,thedualspaceofA~p(φ)isgiven,fourcharacteristicsofCarlesonmeasureonA~p(φ)areobtained.Moreover,asanapplication,threesequenceinterpolationtheoremsinA~p(φ)arederived.
简介:Inthispaperexhaustive-servicepriority-M/G/1queueingsystemswithmultiplevacations,singlevacationandsetuptimesarestudiedunderthenonpreemptiveandpreemptiveresumeprioritydisciplines.Foreachofthesixmodelsanalysed,theLapLace-StieltjestransformofthevirtualwaitingtimeWκ(t)attimetofclasskisderivedbythemethodofcollectivemarks.AsufficientconditionforWκ(t)/√ακdd↑→|U|,whereUhasthestandardnormaldistribution,isalsogiven.
简介:同学们:展示在你们面前的这本书是以华东师范大学版数学实验教材(七年级上)为兰本,按照数学新课程改革的新精神和新要求编写的同步学习用书.这本书将致力于突出数学新课程的基本理念,力求体现学生是学习主人的新课程学习特色,以崭新的内容和新颖的编排向你们展示出一幅幅精美的数学画面,一个个丰富多彩的数学活动,一串串生动有趣的数学问题.它将陪伴你们去观察、实验、探索、推理、交流和议练,在学习过程中获取现实的、有意义的、富有挑战性的数学知识;它将让你在动手实践、自主探索、合作交流、师生互动的学习活动中,更有效地学习数学、理解数学、掌握数学。