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494 个结果
  • 简介:Inthispapertheexistenceanduniquenessofthesolutionofimplicithybridmethods(IHMs)forsolvingtheinitialvalueproblems(IVPs)ofstiffordinarydifferentialequations(ODEs)isconsidered.Weprovidethecoefficientconditionanditsjudgingcriterionaswellastherighthandconditiontoensuretheexistingsolutionuniquely.

  • 标签: TVPs of STIFF system IMPLICIT hybrid
  • 简介:自从环境能力并且象陆地实际上联系了的居民一样可耕全部的平衡,斜坡为各种各样的工程构造正在成为越来越重要的选择。因为斜坡的地质的复杂性,设计和基于斜坡的设计的决策仍然不是实际的完全依靠理论分析和数字计算,但是主要在专家的经验上。因此,它有重要实际意义把一些成功的经验变成数学方程。在在云南设计构造盒子的丰富的典型斜坡之上基于,西南的中国,为分析斜坡稳定性的3个方法在这篇论文被开发了。首先,为分析斜坡稳定性的通信类似的数学方程通过案例研究被建立了。然后,当7个主要影响因素被采用时,人工的神经网络和multivariate回归分析也被建立了。

  • 标签: 斜坡稳定性 地质工程 多元衰退分析 人造神经网络
  • 简介:Thestudyofstructure,thermodynamicstate,equationofstate(EOS)andtransportpropertiesofwarmdensematter(WDM)hasbecomeoneofthekeyaspectsoflaboratoryastrophysics.Thisfieldhasdemonstrateditsimportancenotonlyconcerningtheinternalstructureofplanets,butalsootherastrophysicalbodiessuchasbrowndwarfs,crustsofoldstarsorwhitedwarfstars.Therehasbeenarapidincreaseininterestandactivityinthisfieldoverthelasttwodecadesowingtomanytechnologicaladvancesincludingnotonlythecommissioningofhighenergyopticallasersystems,zpinchesandX-rayfreeelectronlasers,butalsoshort-pulselaserfacilitiescapableofgenerationofnovelparticleandX-raysources.ManynewdiagnosticmethodshavebeendevelopedrecentlytostudyWDMinitsfullcomplexity.Evenultrafastnonequilibriumdynamicshasbeenaccessedforthefirsttimethankstosubpicosecondlaserpulsesachievedatnewfacilities.RecentyearssawanumberofmajordiscoverieswithdirectimplicationstoastrophysicssuchastheformationofdiamondatpressuresrelevanttointeriorsoffrozengiantplanetslikeNeptune,metallichydrogenunderconditionssuchasthosefoundinsideJupiter’sdynamoorformationoflonsdaleitecrystalsunderextremepressuresduringasteroidimpactsoncelestialbodies.Thispaperprovidesabroadreviewofthemostrecentexperimentalworkcarriedoutinthisfieldwithaspecialfocusonthemethodsused.AlltypicalschemesusedtoproduceWDMarediscussedindetail.MostofthediagnostictechniquesrecentlyestablishedtoprobeWDMarealsodescribed.Thispaperalsoprovidesanoverviewofthemostprominentexamplesofthesemethodsusedinexperiments.Eventhoughthemainemphasisofthepublicationisexperimentalworkfocusedonlaboratoryastrophysicsprimarilyatlaserfacilities,abriefoutlineofothermethodssuchasdynamiccompressionwithz-pinchesandstaticcompressionusingdiamondanvilcells(DAC)isalsoincluded.Somerelevanttheoretic

  • 标签: high pressure PHASES laboratory ASTROPHYSICS LASERS
  • 简介:Plantationpoplarisoneofthemostimportantresourcesforwoodindustry,itsutilizationfieldisvast.ThewettabilityofPopulustomentosawithdifferentdryingmethodswasjudgedbymeasurementofcontactangleusingdistilledwaterinthispaper.Theresultsshowedthatthespecimensfromconventionaldryinghavethebiggestcontactangle,andtheairdriedhavethesmallestcontactangle,airdriedlumbershaveabetterwettabilitythanthekilndried.Thechangesofcontactangleinaperiodoftim...

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  • 简介:Avarietyofmatrixrationalinterpolationproblemsincludethepartialrealizationproblemformatrixpowerseriesandtheminimalrationalinterpolationproblemforgeneralmatrixfunctions.Severalproblemsincircuittheoryanddigitalfilterdesigncanalsobere-ducedtothesolutionofmatrixrationalinterpolationproblems[1—4].Bymeansofthereachabilityandtheobservabilityindicesofdefinedpairsofmatrices,Antoulas,Ball,KangandWillemssolvedtheminimalmatrixrationalinterpolationproblemin[1].Onthe

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  • 简介:Withthedevelopmentofgenomesequencingformanyorganisms,moreandmorerawsequencesneedtobeannotated.Genepredictionbycomputationalmethodsforfindingthelocationofproteincodingregionsisoneoftheessentialissuesinbioinformatics.Twoclassesofmethodsaregenerallyadopted:similaritybasedsearchesandabinitioprediction.Here,wereviewthedevelopmentofgenepredictionmethods,summarizethemeasuresforevaluatingpredictorquality,highlightopenproblemsinthisarea,anddiscussfutureresearchdirections.

  • 标签: 基因 预测方法 相似性 马尔可夫模型 序列分析 人类基因组计划
  • 简介:TheGalerkinandleast-squaresmethodsaretwoclassesofthemostpopularKrylovsubspacemethOdsforsolvinglargelinearsystemsofequations.Unfortunately,boththemethodsmaysufferfromseriousbreakdownsofthesametype:InabreakdownsituationtheGalerkinmethodisunabletocalculateanapproximatesolution,whiletheleast-squaresmethod,althoughdoesnotreallybreakdown,isunsucessfulinreducingthenormofitsresidual.Inthispaperwefrstestablishaunifiedtheoremwhichgivesarelationshipbetweenbreakdownsinthetwometh-ods.Wefurtherillustratetheoreticallyandexperimentallythatifthecoefficientmatrixofalienarsystemisofhighdefectivenesswiththeassociatedeigenvalueslessthan1,thentherestart-edGalerkinandleast-squaresmethodswillbeingreatrisksofcompletebreakdowns.Itappearsthatourfindingsmayhelptounderstandphenomenaobservedpracticallyandtoderivetreat-mentsforbreakdownsofthistype.

  • 标签: large linear systems iterative methods Krylov
  • 简介:Weconsidertheclassicalpolicyiterationmethodofdynamicprogramming(DP),whereapproximationsandsimulationareusedtodealwiththecurseofdimensionality.Wesurveyanumberofissues:convergenceandrateofconvergenceofapproximatepolicyevaluationmethods,singularityandsusceptibilitytosimulationnoiseofpolicyevaluation,explorationissues,constrainedandenhancedpolicyiteration,policyoscillationandchattering,andoptimisticanddistributedpolicyiteration.Ourdiscussionofpolicyeva...

  • 标签: 动态编程 政策重复 投射方程 聚集 啁啾 规则化
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  • 简介:Inthispaper,weareconcernedwithuniformsuperconvergenceofGalerkinmethodsforsingularlyperturbedreaction-diffusionproblemsbyusingtwoShishkin-typemeshes.Basedonanestimateoftheerrorbetweensplineinterpolationoftheexactsolutionanditsnumericalapproximation,aninterpolationpost-processingtechniqueisappliedtotheoriginalnumericalsolution.Thisresultsinapproximationexhibitsuperconvergencewhichisuniformintheweightedenergynorm.Numericalexamplesarepresentedtodemonstratetheeffectivenessoftheinterpolationpost-processingtechniqueandtoverifythetheoreticalresultsobtainedinthispaper.

  • 标签: GALERKIN方法 超收敛 奇摄动问题 伽辽金方法 后处理技术 反应扩散问题
  • 简介:ROW-ACTIONMETHODSFORCONVEXQUADRATICPROGRAMMINGGUOTiande(MathematicsDepartmentofQufuNormalUniversity,Qufu,Shandong273165,China...

  • 标签: CONVEX quadratic PROGRAMMING linear PROGRAMMING least-norm
  • 简介:Basedonelementarygrouptheory,theblockpivotmethodsforsolv-ingtwo-dimensionalelasticfrictionalcontactproblemsarepresentedinthispaper.Itisprovedthatthealgorithmsconvergewithinafinitenumberofstepswhenthefrictioncoefficientis'relativesmall'.Unlikemostmathematicalprogrammingmeth-odsforcontactproblems,theblockpivotmethodspermitmultipleexchangesofbasicandnonbasicvariables.

  • 标签: elastic frictional contact TRIAL and error
  • 简介:Thispaperpresentsaclassofhybridone-stepmethodsthatareobtainedbyusingCramer’sruleandrationalapproximationstofunctionexp(q).Thealgorithmsfallintothecatalogueofimplicitformula,whichinvolvessthorderderivativeands+1freeparameters.Theorderofthealgorithmssatisfiess+1≤p≤2s+2.Thestabilityofthemethodsisalsostudied,necessaryandsufficientconditionsforA-stabilityandL-stabilityaregiven.Inaddition,someexamplesarealsogiventodemonstratethemethodpresented.

  • 标签: HYBRID ONE-STEP method RATIONAL APPROXIMATION A-STABILITY
  • 简介:Inthepast,filminglateralradiogramneededtheassociationoffilmingbedandanglewooden-box.Whichhasthedefectsthatitrequiredtoocomplexoperationandcan'tavoidtheeontralateralshoulderwardingofftheray.TheauthorinventedanewwaytofilmLateralradiogramofmandiblethroughyears'practice,whichismoresimpleandconvenientandsuitableforroutineoperation.

  • 标签: 下颚照射 放射医学 X线检查 诊断 检照技术
  • 简介:Errorestimatesareestablishedforthefinitedementmethodstosolveaclassofsecondordernonlinearparabolicequations.OptimalratesofconvergenceinL2-andH1-normsarederived.Meanwhile,theschenesaresecondordercorrectintime.

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