学科分类
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4 个结果
  • 简介:在这份报纸,我们学习交往的散开的线性系统的一个班的一些各态历经的定理,它是一个寓言的安德森模型。首先,在假设下面转变内核=(一(我,j))我,jS是二倍地随机的,我们获得长期的集中到基于自我两重性从围住的一泛音函数h开始的不变的概率措施h性质,然后我们显示出集中到措施h为起始的分布的一个宽广的类保持的不变的概率。秒(一(我,j))我,jS短暂、对称,并且在阀值下面的散开参数c遗体,我们能决定不变的概率与有限的秒测量的extremal的集合时刻。最后,在情况中转变核(一(我,j))我,jS是二倍地随机的并且满足大小写我(看见大小写我在里面[Shiga,T.:在人口遗传的一个交往的系统。J。数学。京都大学,20,213242(1980)]),我们证明这个寓言的安德森模型局部地灭绝独立于散开参数c。

  • 标签: ANDERSON模型 遍历定理 抛物型 不变概率测度 扩散参数 群体遗传学
  • 简介:Asimplifiedmethodforthesimulationoftheergodicspatiallycorrelatedseismicgroundmotionisproposedbasedonthecommonlyusedoriginalspectralrepresentationmethod.Torepresentthecorrelationinthegroundmotion,thephaseanglesaregivenbyexplicittermswithaclearphysicalmeaning.Bytheseexplicitterms,thecomputationalefficiencycanbeimprovedbyconvertingthedecompositionofthecomplexcross-spectralmatrixintothedecompositionoftherealincoherencecoefficientmatrix.Double-indexingfrequenciesareintroducedtosimulatetheergodicseismicgroundmotion,andtheergodicfeatureoftheimprovedmethodisdemonstratedtheoretically.Subsequently,anexplicitsolutionoftheelementsofthelowertriangularmatrixundertheCholeskydecompositionisgiven.Withthisexplicitsolution,theimprovedmethodissimplified,andthecomputationalefficiencycanbeimprovedgreatlybyavoidingtherepetitiveCholeskydecompositionofthecross-spectralmatrixineachfrequencystep.Finally,anumericalexampleshowsthegoodcharacteristicoftheimprovedmethod.

  • 标签: 地震地面运动 运动模拟 空间相关 CHOLESKY分解 遍历 计算效率
  • 简介:Inthispaper,weconsiderthespectrumsharingCognitiveRadio(CR)system,whereinSingle-InputMulti-Output(SIMO)cognitivefadingchannelisassumed.Subjecttotheaveragein-terferenceconstraintofprimaryuser,theergodiccapacityofcognitiveuserinvolvingjointbeamformingandpowercontrolisanalyzed.Wederivetheoptimaljointbeamformingandpowercontrolstrategyanddeducethegeneralintegralexpressionforergodiccapacity.Furthermore,underdifferentchannelfadingsincludingRaleighfading,Nakagami-mfadingandLognormalshadowingfading,thespecificexpressionsofergodiccapacityforSIMOcognitivechannelareexhibited.Mostoftheexpressionsarepresentedinclosed-formorwithsomespecialintegralfunctions.Largeamountofsimulationsareconductedtocorroborateourtheoreticalresults.

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