简介:Anewsimilarsingle-differencemathematicalmodel(SS-DM)anditscorrespondingalgorithmareadvancedtosolvethedeformationofmonitoringpointdirectlyinsingleepoch.ThemethodforbuildingtheSSDMisintroducedindetail,andthemainerrorsourcesaffectingtheaccu-racyofdeformationmeasurementareanalyzedbriefly,andthebasicalgo-rithmandstepsofsolvingthedeform-ationarediscussed.Inordertovalidatethecorrectnessandtheaccuracyofthesimilarsingle-differencemodel,thetestwithfivedualfrequencyreceiversiscarriedoutonaslidewaywhichmovedinplaneinFeb.2001.Inthetest,fivesessionsareobserved.Thenumericalresultsoftestdatashowthattheadvancedmod-eliscorrect.
简介:Parallelmachineproblemswithasingleserverandreleasetimesaregeneralizationsofclassicalparallelmachineproblems.Beforeprocessing,eachjobmustbeloadedonamachine,whichtakesacertainreleasetimesandacertainsetuptimes.Allthesesetupshavetobedonebyasingleserver,whichcanhandleatmostonejobatatime.Inthispaper,wecontinuestudyingthecomplexityresultforparallelmachineproblemwithasingleandreleasetimes.Newcomplexityresultsarederivedforspecialcases.
简介:Aseriesofadvantagesofsingledifference(SD)andundifferenced(ZD)modelsaregivenascomparedwitythedoubledifferenceezistinSDandZDmodels.Thereparameterizationmethodisprovidedtoresolvethisrankdefectproblembyestimatingsomecombinationsoftheunknownsratherthantheunknownsthemselves.TherepatameterizationofSDandZDfunctionalmodelsisdiscussedindetailwiththeirstochasticmodels.Thetheoreticalcomformationoftheequivalenceofundifferencedanddifferencedmodelsisdescribedinastraightforwardway.TherelationshipbetweenSDandZDresidualsisgivenandverifiedforsomespecialpurposes,e.g.researchonthestochasticalpropertiesofGPSobservations.
简介:Anewalgorithm,calledasDouble-EpochAlgorithm(DEA)isproposedinGPSrapidpositioningusingtwoepochsinglefrequencyphasedatainthispaper.Firstly,thestructurecharacteristicofthenormalmatrixinGPSrapidpositioningisanalyzed.Then,inthelightofthecharacteristic,basedonTIKHONOVregularizationtheorem,anewregularizerisdesignedtomitigatetheill-conditionofthenormalmatrix.TheaccuratefloatambiguitysolutionsandtheirMSEM(MeanSquaredErrorMatrix)areobtained,usingtwoepochsinglefrequencyphasedata.CombinedwithLAMBDAmethod,DEAcanfixtheintegerambiguitiescorrectlyandquicklyusingMSEMinsteadofthecovariancematrixoftheambiguities.Comparedwiththetraditionalmethods,DEAcanimprovetheefficiencyobviouslyinrapidpositioning.So,thenewalgorithmhasanextensiveapplicationoutlookindeformationmonitoring,pseudokinematicrelativepositioningandattitudedetermination,etc.