学科分类
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37 个结果
  • 简介:ADRNN(diagonalrecurrentneuralnetwork)anditsRPE(recurrentpredictionerror)learningalgorithmareproposedinthispaper.UsingofthesimplestructureofDRNNcanreducethecapacityofcalculation.TheprincipleofRPElearningalgorithmistoadjustweightsalongthedirectionofGauss-Newton.Meanwhile,itisunnecessarytocalculatethesecondlocalderivativeandtheinversematrixes,whoseunbiasednessisproved.Withapplicationtotheextremelyshorttimepredictionoflargeshippitch,satisfactoryresultsareobtained.Predictioneffectofthisalgorithmiscomparedwiththatofauto-regressionandperiodicaldiagrammethod,andcomparisonresultsshowthattheproposedalgorithmisfeasible.

  • 标签: 船舶工程 人工神经网络 运算法则 结构力学
  • 简介:Inthispaperweshowthcmethodofenergyinpartwithwhichwecangetthemodelofrandomwave,andpredicttherollmotionofunstabilizedshipandstabilizedshipusingthewavemodel.Thecontrolparametersoffinstabilizeraredeterminedaccordingtotheperformanceindex.Thesimulationofthesystemisalsomadeinthispaper.Thecomparisonofthesimulationwithrealshipindicatesthatthemethodcanbeusedinthepredictionofrollmotionofastabilizedshipinrandomwave.

  • 标签: wave model energy in part ROLL
  • 简介:TomwasanAmericanboy.OncehisfatherwantedtogotoChinaforavisit.Beforehestartedout,Tomaskedhim,“AreyougoingtoChinabyplane,bytrainorby”sheep′,father?”

  • 标签: SHEEP SHIP 初中 英语 学习辅导 词汇
  • 简介:研究被做克服在一条航道与一艘轮船的自动驾驶系统联系的传统的问题。一艘轮船有波浪骚乱的动态模型被造;一个波浪过滤器借助于一个扩大状态观察员(ESO)被设计。模型从有颜色的噪音贿赂的出发大小估计了低频率运动部件,因此前后的驾驶由高频率波浪骚乱引起了被避免。同时,一个柔韧的自动驾驶仪系统,由可变结构控制理论设计了,被介绍。在波浪过滤器工作很好的危险的海地位表演完成的模拟结果;自动驾驶仪有强壮的坚韧性到环境骚乱;模型不安,;更重要地,rudder调整的频率显著地被减少。

  • 标签: 滤波器 自动驾驶仪 变结构控制 波状扰动 船舶
  • 简介:SHIPHYDRODYNAMICSBASICRESEARCHINTHEUNITEDSTATES¥EdwinP.Rood(MechanicsandEngergyConversion(333),OfficeofNavalResearchArlington...

  • 标签: SHIP performance SHIP HYDRODYNAMICS COMPUTATIONAL FLUID
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  • 简介:Thesimulationofthewholeship-bridgecollisionprocesscanbeeffectivelycarriedoutbynonlineardynamicfiniteelementmethod.Basedonthesimpledescriptionofthetheory,ascenarioofa40000DWToiltankercollidingwithabridgeacrosstheYangtzeRiverisdesignedforsimulation.Thetechnologyofstructuremodelingandthedeterminationofrelatedparametersareintroduced.Thedeformationofthebulbbow,thehistoryofcollisionforcechange,theexchangeofcollisionenergyandthestressdistributionofthebridgepieraredescribedindetail,whichareofgreatvaluetobridgede-signandbridgepierdamageestimation,Somemechanicalcharactersintheprocessofship-bridgecollisionaredescribed.Moreaccurateresultscanbeproducedbyfiniteelementmethodthanthatbyempiricalformulasandsimplifiedanalyticalmethods.

  • 标签: ship-bridge COLLISION STRUCTURAL DAMAGE NONLINEAR FINITE
  • 简介:Theshipdesignprocessmodelisthebasisfordevelopingtheshipcollaborativedesignsystemundernetworkenvironment.Accordingtothecharacteristicsoftheshipdesign,amethodfordividingtheshipdesignprocessintothreelayersispatforward,thatisprojectlayer,designtasklayeranddesignactivitylayer,thentheformalizeddefinitionsoftheshipdesignprocessmodel,thedecomposingprinciplesoftheshipdesignprocessandthearchitectureoftheshipcollaborativedesign(SDPM)systemarepresented.Thismethodsimplifiestheactivitynetwork,makestheoptimizationandadjustmentofthedesignplanconvenientandalsomakesthedesignprocesseasiertocontrolandchange,atlastthearchitectureoftheshipcollaborativedesignsystemisdiscussed.

  • 标签: 船舶设计 过程模型 计算机 SWBS 结构设计
  • 简介:Onthebasisofenvelopespectrumanalysisofship-radiatednoise,thefeaturesandtheextractingmethodsarediscussed,andthenanewmethodofdynamicrecognitionhasbeenproposed.Usingthismethod,accuraterecognitionratefordifferenttypesofshiptargetscanbeeffectivelyimproved,andsomeoftheimportantparametersoftarget'smovementcanbeobtainedatthesametime.

  • 标签: 动态识别 包络频谱分析 精确识别率 有效改进
  • 简介:Anefficientmulti-blockincompressibleviscousflowsolverbasedonsolvingtheReynolds-AveragedNavier-Stokes(RANS)equationsnumericallyhasbeendevelopedthatcanbeappliedtosimulationofavarietyofshipmaneuveringrelatedflowsandcalculationofhydrodynamicforces.Validationandverificationofthesolutionprocedurewerecarriedoutonseveralmodelproblemswithgoodagreementtoexperimentalandnumericalresults.

  • 标签: 船舶机动 粘性流体 流体力学 数值仿真 计算机虚拟现实
  • 简介:AnewreasonablyperfectdynamicmathematicmodelhasbeenestablishedforcondenserusedinshipnuclearpowerplantaccordingtoitsstructuralfeaturesandOperatingprinciple.ThemodelhasbeensolvedbytheRunge-Kuttamethod.Andananalysisprogramhasbeendevelopedfordynamicnumericalsimulationundersteadyoperationcondition,disturbancecondi-tion,andaccidentcondition.Thedynamiccharacteristicsofcondenserhasbeencalculatedandanalyzedunderseveralkindsof

  • 标签: CONDENSER DYNAMIC MATHEMATICAL model Runge -
  • 简介:BasedonthedoubleFourierintegralrepresentationforsteadyviscousshipwaves,whichinvolvesagenericamplitudefunctionandacomplexdispersionrelation,thephasefunctionforthree-dimensionalshipwavesinthefarfieldwasasymptoticallyderivedbymeansoftheLighthilltwo-stageschemecombiningtheCauchyresiduetheoremandthemethodofsteepestdescents,andtheeffectofviscosityonwavelengthswasnumericallyinvestigatedwiththeNewtoniterationmethod.Itisfoundthatthetransverseanddivergingwavesareelongatedduetothepresenceofviscosityandthelatterismoreheavilyaffectedandthatthephasedifferencesbetweentheviscoustransverseanddivergingwavesarelargerthanthoseofthecorrespondinginviscidwaves.

  • 标签: 自由表面波 复色散关系 粘性流体力学 双傅里叶积分表达式
  • 简介:Forsomelargelydamagedships,theconventionalmethodsareunadaptabletoestimatetheirdynamiccharacteristicsastoshipswithsymmetricalhullsection.Basedondryhullmodalanalysisofflexure-torsioncouplingvibrationofunsymmetricalshipstructuresaboutlongitudinalcenterline,atransfermatrixmethodtocalculatethedynamiccharacteristicsispresented.Takenbothsheareffectandwarpingdeformationsintoaccount,thepointandfieldtransfermatricesarederived,andtheinflu-

  • 标签: damaged SHIP COUPLING VIBRATION WARPING dynamic
  • 简介:SyntheticApertureRadar(SAR)imagingofoceansurfacefeaturesisstudied.ThesimulationoftheturbulentandvorticalfeaturesgeneratedbyamovingshipandSARimagingofthesewakesiscarriedout.Theturbulentwakedampingtheoceansurfacecapillarywavesmaybepartiallyresponsibleforthesuppressionofsurfacewavesneartheshiptrack.Thevortexpairgeneratingachangeinthelateralflowfieldbehindtheshipmaybepartiallyresponsibleforanenhancementofthewavesneartheedgesofthesmootharea.Thesehydrodynamicphenomenaaswellasthechangesofradarbackscattergeneratedbyturbulenceandvortexaresimulated.AnSARimagingmodelisthenusedonsuchoceansurfacefeaturestoprovideSARimages.Comparisonoftwoships'simulatedSARimagesshowsthatthewakefeaturesaredifferentforvariousshipparameters.

  • 标签: 成象模拟 SAR 合成孔径雷达 湍流迹 飞船
  • 简介:TheanalysisandevaluationofanactualportsystemcontainingRdifferentship’skindsandNsubsystemseachofwhichconsistsofM.(i=1,2,…,N)portsarederived.TheexternalarrivalsofshipstothesystemcomefromRdifferentPoissonsourcesandtheinterarrivalstothequeueofeachportofasubsystemaredeterminedaccordingtoconditionprobabilities.EachporthasmultipleberthswhoseservicetimesaredistributedaccordingtoErlangprobabilitydistributionfunctions.EachportofasubsystemhasRinfinitecapacitybuffersforstoringshipsinterarrived.Thismethodprovidesagoodapproximationprocedureforobtainingsystemperfor-mancemeasuressuchaswaitingtimesofships,averagequeuelengths,etc.Optimumportcapacitycanthusbeevaluatedbyusingthisanalysis.Asimulationisalsopresentedtotestthisapproximateanalysis,andagoodagreementisobserved.Thismodelshallbeusedintheplanningofseveralactualportsystems.Throughtheapplicationofthismodel,itispossibletoanalyzeandevaluateperformancesofthesystems.

  • 标签: PORT system QUEUEING NETWORK simulation and
  • 简介:Thispaperintroducesthecomposition,controlmethodandtestingresultsoftheintegratedcontrolsystemforthefirsttidalflowelectricitygenerating(TFEG)shipofChina.Thecontrolmethod,controlalgorithmandthespecificcircuitsforthehydrauliessystemarealsointroduced.Ourresearchworksareemphasizedonthecontrolalgorithmofstabilizingfrequencyandsomespecialproblemsofthecontroller.TherelatedprotectionmeasuresforhydraulicsystemandTFEGsystemhavebeentak-

  • 标签: TFEG stabilizing FREQUENCY prolection ALGORITHM
  • 简介:TherobustnessofLQGdesigningforlatitudinalmovementofshipismainlydiscussed,whenitshydrodynamicparametersfluctuatearoundcriterionvalueatrandomontheproportionaldistributing.Whenagivenshipstateatthespeedof18knandthecourseof45°underRank5stateofsea,andthehydrodynamicparametersoftheshipfluctuateatrandomontheproportionaldistributingwitharangeof±10%,±20%,±30%,therobustnessofmultivariateLQGdesigningforshipisanalyzedwithapplyingtheprobabilitymodelingofrelativecontrollingeffect.TheresultofsimulatingshowsthatwhenthehydrodynamicparametersofshipfluctuatestherelativecontrollingeffectoftheLQGdesigningsubmittonormaldistributionandthemeanvalueofrelativecontrollingeffecthasnoremarkablechangescomparingtothatwithoutperturbationofhydrodynamicparameter.

  • 标签: 船舶设计 水流运动 模型设计 多变量