简介:Inthispaper,theunderwatervehicle,slingandthemothershipareconsideredasasinglede-greeoffreedomsystemconnectedbyaspring.Throughtheanalysisofthissystem,aphysicalmodelises-tablished,whichdescribesthemotionofthevehiclecausedbytheshipmotionandwavemotion.Furthermore,amathematicalmodelbasedonthisphysicalmodelisobtained,andanumericalsolutionprogramismade.Asanexample,apracticallaunchandrecoverysystemforanunderwaterrobotiscalcu-latedbyuseoftheprogram.andthemotiontrackoftherobotisobtained.
简介:TheDalianFujiaGroupbyhinginguponthearomaticsprojectandmakinguseofitsownadvantagesintendstolaunchtheconstructionofthenaphthasteamcrackingandtheMTOprojectinordertodevelopthemanufactureofethylene,propyleneandtheirdownstreamhigh-gradeorganicsynthesismaterials,specialtychemicalfeedstocksandfunctionalhighmolecularmaterials.Theproposedsizeofproductionunits
简介:当它极大地影响用户满足的度,申请发射性能对系统站台开发者和供应商很重要。改进应用程序发射性能的最最有效的方法是用一个稳固的州的驱动器(SSD)代替一个硬盘驱动器(HDD),它最近变得买得起、流行。一个自然问题当时是是否用一个新SSD知道的优化器代替传统的HDD知道的申请发射台。我们由在SSD上分析HDD知道的申请发射台的无效然后建议预取计划的新SSD知道的应用探讨这个问题,叫了快申请跑步者(快)。关键想法快是重叠有SSD存取(I/O)的计算(中央处理器)时间时间在应用程序发射期间。快由一套用户级的部件和LinuxOS(操作系统)提供的系统调试工具组成。因此,没有核重新编译,能容易快在任何最近的Linux版本被部署。我们与运用Linux2.6.32OS的SSD在桌面PC上快实现并且由运行一套使用得广泛地的应用程序评估它,表明象与没有prefetcher的PC相比的申请发射时间的28%减小的一般水准。
简介:Thearticlestudiestheinternationalfinancialservice,whichmightbeopenedbyChinaPost.Basedondefiningpostalfinancialservice,itanalysestheface-to-facecircumstancesandchallengesbyusingthemethodofnormalmarketpositionandthemethodofGeneralElectricCompany(GEC).FinallyitdefinesthemarketpositionofPostalFinancialInternationalService(PFIS).
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简介:ThedesignofnewSatelliteLaunchVehicle(SLV)isofinterest,especiallywhenacombinationofSolidandLiquidPropulsionisincluded.ProposedisaconceptualdesignandoptimizationtechniqueformultistageLowEarthOrbit(LEO)boundSLVcomprisingofsolidandliquidstageswiththeuseofGeneticAlgorithm(GA)asglobaloptimizer.ConvergenceofGAisimprovedbyintroducinginitialpopulationbasedontheDesignofExperiments(DOE)Technique.LatinHypercubeSampling(LHS)-DOEisusedforitsgoodspacefillingproperties.LHSisastratifiedrandomprocedurethatprovidesanefficientwayofsamplingvariablesfromtheirmultivariatedistributions.InSLVdesignminimumGrossLiftoffWeight(GLOW)conceptistraditionallybeingsought.SincethedevelopmentcoststendtovaryasafunctionofGLOW,thisminimumGLOWisconsideredasaminimumdevelopmentcostconcept.Thedesignapproachismeaningfultoinitialdesignsizingpurposeforitscomputationalefficiencygivesaquickinsightintothevehicleperformancepriortodetaileddesign.
简介:Tobeclosetothepracticalflightprocessandincreasetheprecisionofoptimaltrajectory,asix-degree-offreedom(6-DOF)trajectoryisoptimizedforthereusablelaunchvehicle(RLV)usingtheGausspseudospectralmethod(GPM).DifferentfromthetraditionaltrajectoryoptimizationproblemwhichgenerallyconsiderstheRLVasapointmass,thecouplingbetweentranslationaldynamicsandrotationaldynamicsistakenintoaccount.Anoptimizationproblemisformulatedtominimizeaperformanceindexsubjectto6-DOFequationsofmotion,includingtranslationalandrotationaldynamics.Atwo-stepoptimalstrategyisthenintroducedtoreducethelargecalculationscausedbymultiplevariablesandconvergenceconfinementin6-DOFtrajectoryoptimization.Thesimulationresultsdemonstratethatthe6-DOFtrajectoryoptimalstrategyforRLVisfeasible.
简介:OnApril11,2011thecommercialscaleapplicationtestoftheCTV-VItypecatalystdevelopedbytheSINOPECShanghaiPetrochemicalResearchInstitute(SPRI)wasconductedattheNo.2vinylacetateunitoftheShanghaiPetrochemicalCompany,withthestartupoftheprocessunitrealizedsuccessfullyatthefirstattempt.Theproposal