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  • 简介:TheconvergenceoftheparallelmatrixmultisplittingrelaxationmethodspresentedbyWang(LinearAlgebraandItsApplications154/156(1991)473-486)isfurtherinvestigated.Theinvestigationsshowthattheserelaxationmethodsreallyhaveconsiderablylargerconvergencedomains.

  • 标签: 收敛域 矩阵多重分裂反射法 线性代数 SIMD 多过程系统
  • 简介:Indownlinkcoordinatedmulti-point(CoMP)system,fullcooperationisalwaysnotapplicableinrealworldbecauseofitshighrequestinthebackhaul.Todealwiththisproblem,clusteringdecisionismadetoprocesstransmission.Inthispaperclusteringmethodsbasedonthemetricsignal-to-leakage-plus-noise(SLNR)isproposed.Inaddition,userschedulingschemesbasedonSLNRisalsoputuptomaketheschedulingsetaslargeaspossible.Simulationresultsshowthattheproposedclusteringmethodsnotonlyreducethedatasharingamongthecooperatingbasestations(BSs),butalsoimprovethesystemthroughputcomparedwiththetraditionalclusteringmethodsbasedonchannelstrength.

  • 标签: 聚类方法 调度方法 P系统 下行链路 COM 现实世界
  • 简介:1.IntroductionThediscretizationofmanysecondorderselfadjointellipticboundaryvalueproblemsbythefiniteelementmethodleadstolargesparsesystemsoflinearequationswithsymmetricpositivedefinite(SPD)coefficientmatrices.Fortheselinearsystems,algebraicmultilevelp...

  • 标签: MULTILEVEL METHOD POLYNOMIAL ACCELERATION finite element
  • 简介:Thispaperdealswiththenumericalsolutionofinitialvalueproblemsforsystemsofdifferentialequationswithadelayargument.Thenumericalstabilityofalinearmultistepmethodisinvestigatedbyanalysingthesolutionofthelestequationy’(t)=Ay(t)+By(1-t),whereA,BdenoteconstantcomplexN×N-matrices,andt>0.Weinvestigatecarefullythecharacterizationofthestabilityregion.

  • 标签: NUMERICAL stability linear mullistep method DELAY
  • 简介:From1990to2000,weusedHanssonpin,AOhollow-pullingscrew,andbendablescrewtotreat150casesoffreshfemoralneckfractureandtheresultwasanalysedtocomparetheefficacyofthethreemethodsofinternalfixation.

  • 标签: 股骨颈骨折 内固定 疗效评定 骨折治疗
  • 简介:ThevalueofaEuropeanoptionsatisfiestheBlack-Scholesequationwithappropriatelyspecifiedfinalandboundaryconditions.Wetransformtheproblemtoaninitialboundaryvalueproblemindimensionlessform.Therearetwoparametersinthecoefficientsoftheresultinglinearparabolicpartialdifferentialequation.Forarangeofvaluesoftheseparameters,thesolutionoftheproblemhasaboundaryoraninitiallayer.Theinitialfunctionhasadiscontinuityinthefirst-orderderivative,whichleadstotheappearanceofaninteriorlayer.Weconstructanalyticallytheasymptoticsolutionoftheequationinafinitedomain.Basedontheasymptoticsolutionwecandeterminethesizeoftheartificialboundarysuchthattherequiredsolutioninafinitedomaininxandatthefinaltimeisnotaffectedbytheboundary.Also,westudycomputationallythebehaviourinthemaximumnormoftheerrorsinnumericalsolutionsincasessuchthatoneoftheparametersvariesfromfinite(orprettylarge)tosmallvalues,whiletheotherparameterisfixedandtakeseitherfinite(orprettylarge)orsmallvalues.Crank-Nicolsonexplicitandimplicitschemesusingcenteredorupwindapproximationstothederivativearestudied.Wepresentnumericalcomputations,whichdetermineexperimentallytheparameter-uniformratesofconvergence.Wenotethatthisrateisratherweak,dueprobablytomixedsourcesoferrorsuchasinitialandboundarylayersandthediscontinuityinthederivativeofthesolution.

  • 标签: 选件 奇点 有限微分法 单调鲁棒性
  • 简介:Thispaperconsiderstheasymptoticstabilityanalysisofbothexactandnumericalsolutionsofthefollowingneutraldelaydifferentialequationwithpantographdelay.{x′(t)+Bxd(t)+Cx′(qt)+Dx(qt)=0,t>0,x(0)=X0,}whereB,C,D∈C^d×d,q∈(0,1),andBisregular.Aftertransformingtheaboveequationtonon-automaticneutralequationwithconstantdelay,wedeterminesufficientconditionsfortheasymptoticstabilityofthezerosolution.Furthermore,wefocusontheasymptoticstabilitybehaviorofRunge-Kuttamethodwithvariablestepsize.ItisprovedthataLstableRunge-Kuttamethodcanpreservetheabove-mentionedstabilityproperties.

  • 标签: 渐近性 稳定性 朗格矢量法 延迟 渐近稳定度 微分方程
  • 简介:ThispaperprovidesanoverviewofthedevelopmentsinanalyticalandtestingmethodsandexperimentalsimulationsongashydrateinChina.Inthelaboratory,theanalysesandexperimentsofgashydratecanprovideusefulparametersforhydrateexplorationandexploitation.Inrecentyears,modemanalyticalinstrumentsandtechniques,includingLaserRamanspectroscopy(Raman),X-raydiffraction(XRD),X-raycomputedtomography(X-CT),scanningelectronmicroscope(SEM),nuclearmagneticresonance(NMR)andhighpressuredifferentialscanningcalorimetry(DSC),wereappliedinthestudyofstructure,formationmechanisms,phaseequilibrium,thermalphysicalpropertiesandsoforthofgashydrates.Thedetectiontechnologyandtime-domainreflectometry(TDR)techniqueareintegratedtotheexperimentaldevicestostudythephysicalparametersofgashydrates,suchastheacoustics,resistivity,thermal,andmechanicalproperties.Itisbelievedthatthevariousanalyticaltechniquestogetherwiththeexperimentalsimulationsfromlarge-scaletomicro-scaleongashydratewillplayasignificantroleandprovideapowerfulsupportforfuturegashydrateresearches.

  • 标签: GAS HYDRATE ANALYTICAL method Expermaental SIMULATION
  • 简介:1.IntroductionTherehasbeenalotofliterature(see[1]--[61and[12])ontheparalleliterativemethodsforthelarge--scalesystemoflinearequationsinthesenseofmatrixmultisplittingsincethepioneeringworkofO’LearyandWhite(see[l])waspublishedin1985.Oneofthemostrecentre...

  • 标签: Solution of linear systems ASYNCHRONOUS PARALLEL
  • 简介:Inthispaper,accordingtotheFujianSeismicNetworkearthquakecatalogrecords,theTnowmethodandtheFourStationsContinuousLocationmethod(hereinaftercalledFSCL)putforwardbyJinXingareinspectedbyusingP-wavearrivalinformationofthefirstfourstationsofeachseismicevent.Resultsshowthatforearthquakeswithinthenetwork,bothmethodscanobtainsimilarlocationresultsandlocationdeviationsaresmallforthemajorityoftheevents.Forearthquakesoutsidethenetwork,thelocationdeviationmaybeamplifiedastheepicentraldistanceincreases,owingtotheseismicstationdistributionwhichspreadtowardthesideoftheepicenterandthesmallopeninganglebetweenseismicstationsusedforlocatingandepicenter.FortheFSCLmethod,theimpactsofthewavevelocityonthelocationresultsmaybesignificantforearthquakesoutsidethenetwork.Thus,selectingavelocitymodelwhichissimilartotheactualstructureofthewavevelocitywillcontributetoimprovinglocationresultsofearthquakes.TheFSCLmethodcanlocatemoreseismiceventsthantheTnowmethod.ItconcludesthattheTnowmethodmakesuseofmistakeinformationfromsomenon-triggeringstationsinearthquakecatalog,andsomeP-wavearrivalsarenotincludedintheearthquakecatalogduetodiscontinuousrecordsorunclearrecordsoftheseismicphase,whichinducesincorrectlocation.

  • 标签: 地震定位方法 地震预警 位置偏差 地震目录 地震事件 错误信息
  • 简介:静电干扰是为处理深思考的大挑战地震数据。在这份报纸,几个不同静电干扰答案在处理深思考被实现了在华南和他们的相应结果的地震数据被比较了以便发现合适的静电干扰答案。任何一个静电干扰解决方案基于tomographic原则或把领域静电干扰的低频率的部件与相结合高周波折射静电干扰之一能为深思考提供合理静电干扰解决方案在有很崎岖的表面地形学的华南的地震数据,并且二个静电干扰解决方案能改正两长空间的波长和短的静电干扰异例。表面一致的剩余静电干扰修正能用作好赔偿到几种第一个静电干扰答案。合适的静电干扰答案能改进地震的节的质量和决定,特别为在最高的披风的莫霍的思考。

  • 标签: 地震数据 深反射 静校正方法 中国南方 折射静校正 剩余静校正
  • 简介:客观:为了选择腰部的transpedicular的一个合适的方法,在三个方法之中在不同腰部的层次拧紧固定(Roy-Camille“s方法,Magerl”s方法和杜“smethod)在中国人口。方法:三维(3-D)图象与被电子横梁CT扫描的42个成年腰部的片断的图象数据被重建。腰部的小花梗螺丝钉固定的三个方法在3-D上被模仿重建的图象和植入小花梗螺丝钉的参数被测量。结果:在从入口点的距离有统计上重要的差别到在三个方法之间的小花梗轴(P<0.001)。Thedistances由“s方法从L1是最短的到L4,并且距离测量了byMagerl”的杜测量了s方法在L5是最短的(P<0.05)。从L1没有重要差别到L2(P>0.05),但是对在插入TSA(横向的节角度)的安全范围的L5的从L3的重要差别在三个方法之间被发现(P<0.05)。从L3到L4,TSA的插入的安全范围由杜测量了“s”和Magerls方法比那测量byRoy-Camille显著地大“s方法(P<0.05),但是他们之间没有重要差别(P>0.05)。AtL5,TSA的插入的安全范围由Magerl测量了“s方法在三个方法之中是最大的(P<0.05)。结论:在三个方法之中,杜“因为它到小花梗轴的从入口点的距离最短,TSA的安全范围最大,s方法是从L1toL4的最好的选择;Magerl“s方法能从L3被使用到L5并且是在L5的最好的选择;Roy-Camille”s方法在L1和L2是适用的。

  • 标签: X线检查 腰椎损伤 临床表现 病理机制
  • 简介:Manynaturalproductscontainγ-lactonemoieties.Forexample,β-methyl-γ-butyl-γ-lactones(quercuslactones)aregradientsofagedwhiskey,andβ-methyl-γ-(3-methyl-2-butenyl)-γ-lactone(eldanolide)isapheromoneoftheAfricansugarcaneborer.Wesynthesizedsuchγ-lactonesbyhydrolysesofthehomoallylicalcoholsobtainedbyadditionofaldehydestotheallylicanionsgeneratedfromketenedithioacetalsor2-propenyl-1,3-dithiane.

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