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:The(Nrlund)logarithmicmeansoftheFourierseriesoftheintegrablefunctionfis:1/l_nsumfromk=1ton-1S_k(f)/(n-k),wherel_n:=sumfromk=1ton-11/kInthispaperwediscusssomeconvergenceanddivergencepropertiesofthislogarithmicmeansoftheWalsh-Fourierseriesoffunctionsintheuniform,andintheL~1Lebesguenorm.Amongothers,asanapplicationofourdivergenceresultswegiveanegativeanswertoaquestionofMóriczconcerningtheconvergenceoflogarithmicmeansinnorm.
简介:ConformationofL-lysineinaqueoussolutionwasinvestigatedbylanthanideshiftprobes(Dy,Ho,Er,TmandYb).Reilley’smethodwasemployedtoseparatethecontactanddipolarcom-ponentsofthe13Cparamagneticshifts.ThisstudyrevealsthatCαshifthasthelargestcontactcon-tributionwhiletheothercarbonshiftsaredominatedbythedipolarcontribution.TheaverageoverallconformationofL-lysineinaqueoussolutionisextendedwiththemolecularbackboneintransform.Inthecomplex,lanthanideioncoordinatestothecarboxylgroupwithLn—Obondlength2.2/nandthewholeligandislocatedoutsidethezero-dipolarshiftconeofthelanthanideion.Theelectronicspindensitydistributionontheligandnucleishowsthatthespinpolarizationisthepredominantmech-anismofthecontactinteractionfornucleiincloseproximitytotheboundlanthanideion.