学科分类
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5 个结果
  • 简介:Leta,b,cberelativelyprimepositiveintegerssuchthata2+b2=c2.Je′smanowicz’conjectureonPythagoreannumbersstatesthatforanypositiveintegerN,theDiophantineequation(aN)x+(bN)y=(cN)zhasnopositivesolution(x,y,z)otherthanx=y=z=2.Inthispaper,weprovethisconjectureforthecasethataorbisapowerof2.

  • 标签: JESMANOWICZ猜想 DIOPHANTINE方程 正整数 c++ 勾股数 正解
  • 简介:Generalizedcase-cohortdesignhasbeenprovedtobeacost-effectivewaytoenhancetheefficiencyoflargeepidemiologicalcohort.Inthisarticle,weproposeaninferenceprocedureforestimatingtheunknownparametersinCox’sproportionalhazardsmodelingeneralizedcase-cohortdesignandestablishanoptimalsamplesizeallocationtoachievethemaximumpoweratagivenbudget.Thefinitesampleperformanceoftheproposedmethodisevaluatedthroughsimulationstudies.TheproposedmethodisappliedtoarealdatasetfromtheNationalWilm’sTumorStudyGroup.

  • 标签: 队列分析 风险模型 COX 比例 病例 广义
  • 简介:Inthispaper,westudyoptimalrecovery(reconstruction)offunctionsonthesphereintheaveragecasesetting.WeobtaintheasymptoticordersofaveragesamplingnumbersofaSobolevspaceonthespherewithaGaussianmeasureintheLd-1q(S)metricfor1≤q≤∞,andshowthatsomeworst-caseasymptoticallyoptimalalgorithmsarealsoasymptoticallyoptimalintheaveragecasesettingintheLdq(S-1)metricfor1≤q≤∞.

  • 标签: SOBOLEV空间 测量范围 平均数 最优恢复 球面函数 设置