简介:ThispaperaddressestheintegratedEarthobservationsatelliteschedulingproblem.Itisacomplicatedproblembecauseobservinganddownloadingoperationsarebothinvolved.Weuseanacyclicdirectedgraphmodeltodescribetheobservinganddownloadingintegratedschedulingproblem.Basedonthemodelwhichconsideringenergyconstraintsandstoragecapacityconstraints,wedevelopanefficientsolvingmethodusinganovelquantumgeneticalgorithm.Wedesignanewencodinganddecodingschemethatcangeneratefeasiblesolutionandincreasethediversityofthepopulation.TheresultsofthesimulationexperimentsshowthattheproposedmethodsolvestheintegratedEarthobservationsatelliteschedulingproblemwithgoodperformanceandoutperformsthegeneticalgorithmandgreedyalgorithmonallinstances.
简介:ThispaperixdevotedtoestablishmentoftheChebyshevpseudospectraldomainde-compositionschemeforsolvingtwo-dimensionalellipticequation.Bythegeneralizedequivalentvariatiunalform,wecangetthestabilityandconvergenceofthisnewscheme.
简介:TheevolutionequationsofmomentsfortheBrowniancoagulationofnanoparticlesinbothcontinuumandfreemoleculeregimesareanalyticallystudied.TheseequationsarederivedusingaTaylor-expansiontechnique.Theself-preservingsizedistributionisinvestigatedusinganewlydefineddimensionlessparameter,andtheasymptoticvaluesforthisparameteraretheoreticallydetermined.Thedimensionlesstimerequiredforaninitialsizedistributiontoachieveself-preservationisalsoderivedinbothregimes.Oncethesizedistributionbecomesself-preserving,thetimeevolutionofthezerothandsecondmomentscanbetheoreticallyobtained,anditisfoundthatthesecondmomentvarieslinearlywithtimeinthecontinuumregime.Equivalentequations,ratherthantheoriginalonesfromwhichtheyarederived,canbeemployedtoimprovetheaccuracyoftheresultsandreducethecomputationalcostforBrowniancoagulationinthecontinuumregimeaswellasthefreemoleculeregime.
简介:Thispaperdealswithabi-extrapolatedsubgradientprojectionalgorithmbyintroducingtwoextrapolatedfactorsintheiterativesteptosolvethemultiple-setssplitfeasibilityproblem.Thestrategyisintendtoimprovetheconvergence.Anditsconvergenceisprovedundersomesuitableconditions.Numericalresultsillustratethatthebi-extrapolatedsubgradientprojectionalgorithmconvergesmorequicklythantheexistingalgorithms.
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简介:Forill-posedbilevelprogrammingproblem,theoptimisticsolutionisalwaysthebestdecisionfortheupperlevelbutitisnotalwaysthebestchoiceforbothlevelsiftheauthorsconsiderthemodel'ssatisfactorydegreeinapplication.Toacquireamoresatisfyingsolutionthantheoptimisticonetorealizethetwolevels'mostprofits,thispaperconsidersbothlevels'satisfactorydegreeandconstructsaminimizationproblemofthetwoobjectivefunctionsbyweightedsummation.Then,usingthedualitygapofthelowerlevelasthepenaltyfunction,theauthorstransferthesetwolevelsproblemtoasingleoneandproposeacorrespondingalgorithm.Finally,theauthorsgiveanexampletoshowamoresatisfyingsolutionthantheoptimisticsolutioncanbeachievedbythisalgorithm.
简介:Inthispaper,weproposeanearlyanalyticexponentialtimedifference(NETD)methodforsolvingthe2Dacousticandelasticwaveequations.Inthismethod,weusethenearlyanalyticdiscreteoperatortoapproximatethehigh-orderspatialdifferentialoperatorsandtransformtheseismicwaveequationsintosemi-discreteordinarydifferentialequations(ODEs).Then,theconvertedODEsystemissolvedbytheexponentialtimedifference(ETD)method.WeinvestigatethepropertiesofNETDindetail,includingthestabilityconditionfor1-Dand2-Dcases,thetheoreticalandrelativeerrors,thenumericaldispersionrelationforthe2-Dacousticcase,andthecomputationalefficiency.Inordertofurthervalidatethemethod,weapplyittosimulatingacoustic/elasticwavepropagationinmultilayermodelswhichhavestrongcontrastsandcomplexheterogeneousmedia,e.g.,theSEGmodelandtheMarmousimodel.Fromourtheoreticalanalysesandnumericalresults,theNETDcansuppressnumericaldispersioneffectivelybyusingthedisplacementandgradienttoapproximatethehigh-orderspatialderivatives.Inaddition,becauseNETDisbasedonthestructureoftheLiegroupmethodwhichpreservesthequantitativepropertiesofdifferentialequations,itcanachievemoreaccurateresultsthantheclassicalmethods.
简介:Anewandeffcientthree-dimensionalimplicithybrdschemeforEulerequatiopnsispresented.ThebasicschemeisthecouplingoftheJamesonandTurkel'sLUdecompositionsandProf.ZhangHanxin'sNNDconcept.TheimprovedLUdecompositionsareappliedtodiscretizedtheimplicitpartoftheEulerEquationsandZhang'smodifiedfluxfunctiontocalculatetherighthandsideoperatorsofthehybridscheme,Numericalcalculationsweremadeofsupersonicinletflowswithmixedexternal-internalcompressions,Someofthecomputedresultswerecomparedwithavailablewindtunneldata.
简介:Inthispaper,afullythird-orderaccurateprojectionmethodforsolvingtheincompressibleNavier-Stokesequationsisproposed.Toconstructthescheme,acontinuousprojectionprocedureisfirstlypresented.Wethenderiveasufficientconditionforthecontinuousprojectionequationstobetemporallythird-orderaccurateapproximationsoftheoriginalNavier-Stokesequationsbymeansofthelocaltruncation-error-analysistechnique.Thecontinuousprojectionequationsarediscretizedtemporallyandspatiallytothird-orderaccuracyonthestaggeredgrids,resultinginafullythird-orderdiscreteprojectionscheme.Thepossibilitytodesignhigher-orderprojectionmethodsisthusdemonstratedinthepresentpaper.Aheuristicstabilityanalysisisperformedonthisprojectionmethodshowingtheprobabilityofitsbeingstable.Thestabilityofthepresentschemeisfurtherverifiedthroughnumericaltests.Thethird-orderaccuracyofthepresentprojectionmethodisvalidatedbyseveralnumericaltestcases.
简介:Anewsimilarsingle-differencemathematicalmodel(SS-DM)anditscorrespondingalgorithmareadvancedtosolvethedeformationofmonitoringpointdirectlyinsingleepoch.ThemethodforbuildingtheSSDMisintroducedindetail,andthemainerrorsourcesaffectingtheaccu-racyofdeformationmeasurementareanalyzedbriefly,andthebasicalgo-rithmandstepsofsolvingthedeform-ationarediscussed.Inordertovalidatethecorrectnessandtheaccuracyofthesimilarsingle-differencemodel,thetestwithfivedualfrequencyreceiversiscarriedoutonaslidewaywhichmovedinplaneinFeb.2001.Inthetest,fivesessionsareobserved.Thenumericalresultsoftestdatashowthattheadvancedmod-eliscorrect.
简介:Thispaperproposesanonmonotonicbacktrackingtrustregionalgorithmviabilevellinearprogrammingforsolvingthegeneralmulticommodityminimalcostflowproblems.Usingthedualitytheoryofthelinearprogrammingandconvextheory,thegeneralizeddirectionalderivativeofthegeneralmulticommodityminimalcostflowproblemsisderived.Theglobalconvergenceandsuperlinearconvergencerateoftheproposedalgorithmareestablishedundersomemildconditions.