简介:摘要院本文采用偏最小二乘回归模型(PLS),以泰国菠萝贸易为例,通过变量投影重要性准则筛选自变量,由交叉有效性提取主成分,进而建立偏最小二乘回归模型。深入分析了各指标对泰国菠萝出口贸易的影响。研究表明泰国菠萝出口与原料价格及工厂生产加工速度密切相关,并且偏最小二乘回归的拟合效果优于普通最小二乘回归。
简介:Inthesystemofm(m≥2)seeminglyunrelatedregressions,weshowthattheGauss-Markovestimator(GME)ofanyregressioncoefficientshasuniquesimplifiedform,whichexactlyequalstotheonestepcovariance-adjustedestimatoroftheregressioncoefficients,andhenceweconcludethatforanyfinitek≥2thek-stepcovariance-adjustedestimatordegeneratestotheone-stepcovariance-adjustedestimatorandthecorrespondingtwo-stageAitkenestimatorhasexactlyonesimplifiedform.Also,theuniquesimplifiedexpressionoftheGMEisjusttheestimatorpresentedintheTheorem1ofWang’work[1988].Anewestimateofregressioncoefficientsinseeminglyunrelatedregressionsystem,ScienceinChina,SeriesA10,1033-1040].
简介:TheconcernoveroutliersisoldsinceBernoulli(see[12]),reviewedhistoricallyby[11]andupdatedwith[10]intheirencyclopediatextbook.Jamesetal.[46]usedsimulationtechniquetocomparesomerecentpublishedoutlierdetectionprocedures.Thehistoryofadeptanddiagnosisofoutliersistracedfromoldandpresencecomments.Theil-typeorRank,Brown-Mood,Lp,M,adaptiveM,GM,andTrimmed-Winsorizationestimatorsarethemostpopularestimatorsthatwewillreviewinthispaperasanapplicationtooutlieraccommodation.Wewillreviewandcomparethemostnumericalandgraphicaldisplaysbasedonresidualstoflagoutliers.
简介:也许你吃过蛋炒饭、煲仔饭,但你吃过菠萝饭吗?怎么样,听着就流口水了吧,今天我就来尝试做一做。说干就干,我立刻出去买回来一个黄灿灿的菠萝。第一步,先煮米饭,然后开始处理菠萝。我把菠萝立在桌上,在妈妈的指导下,先把菠萝长叶子的一头切掉一部分,接下来就要把菠萝肉挖出来,把菠萝变成一个"碗"。第二步,把挖出来的果肉和火腿肠切成小丁备
简介: 维高握住妻子的手坐在她旁边,妻子躺在病床上.他想看看妻子吃东西了没有,哪怕是一点点.饭桌上的汤纹丝未动,已不再冒热气.4个孩子走到母亲的病床前沉默着.孩子们大的12岁,最小的5岁.……