简介:为了从期刊文献的学科属性实现族性检索,为文章的分类统计创造条件,本刊2005起均对具有文献标识码的文章采用《中国图书馆分类法》(第四版)进行分类后。标识分类号文章一般标识1个分类号,多个主题的文章可标识2个或3个分类号;主分类号排在第一位,多个分类号之间应以分号分隔。希望有条件查询的作者在来稿时自行标明中图分类号。
简介:Apiecewisecubiccurvefittingalgorithmpreservingmonotonicityofthedatawithoutmodificationoftheassignedslopesigproposed.ThealgorithmhasthesameorderofconvergenceasYan’salgorithm[8]andGasparo-Morandi’salgorithm[5]foraccurateorO(hq)accurategivendata,butithasamorevisuallypleasingcurvethanthosetwoalgorithms.WealsodiscusstheconvergenceorderofcubicrationalinterpolationforO(hq)accuratedata.
简介:Theaimofthisinvestigationistostudyhowtouseagravimetric(quasi)geoidforlevellingbyGPSdatainanoptimalway.TheadventofprecisegeodeticGPShasmadetheuseofatechniquepossible,whichmightbecalledGPS-gravimetricgeoiddetermination.Inthisapproach,GPSheightsabovethereferenceellipsoidaredeterminedforpointswhoselevelled(orthometric)heightHisabovesealevelpeoplehavealreadysurveyed;forthesepoints,wethushavethevaluesofthegeoidundulationN.ThesevaluesarethenusedtoconstrainthegeoidundulationsN′obtainedfromthegravimetricsolution.
简介:SeveralARMAmodelingapproachesareaddressed.Inthesemethodsonlypartofacorrelationsequenceisemployedforestimatingparameters.Itissatisfying,ifthegivencorrelationsequenceisofrealARMA,sinceanARMAprocesscanbecompletelydeterminedbypartofitscorrelationse-quence.Butforthecaseofameasuredcorrelationsequencethewholesequencemaybeusedtore-ducetheeffectoferroronmodelparameterestimation.Inaddition,thesemethodsnowdonotguar-anteeanonnegativespectralestimate.Inviewoftheabove-mentionedfact,aconstrainedleastsquaresfittingtechniqueisproposedwhichutilizesthewholemeasuredcorrelationsequenceandguar-anteesanonnegativespectralestimate.
简介:AfterreviewingtheanalyticaltheoriesofT-Scurve,somemethodsofT-Srelationship,andfuzzysetsforstudyingwatermasses,newmethodsoffittingthemembershipfunctionofoceanicwatermassesarepresentedbasedonthecharacteristicsofT-Scurvefamilyofoceanicwatermasses.ThemembershipfunctionsofoceanicSubsurfaceWaterMasswithhighsalinityandIntermediateWaterMasswithlowsalinityarefittedanddiscussedusingthenewmethods.Theproposedmethodsareusefulinanalyzingthemixingandmodifyingprocessesofthesewatermasses,especiallyintracingtheirsources.Theprinciplesandformulaeofthenewmethodsandexamplesaregiven.