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78 个结果
  • 简介:之前,我们在WordTown认识了陆上、空中的主要交通工具——bus、train和plane。这次,我们迎来了水上大家族——ship和它的兄弟姐妹!

  • 标签: 英语 阅读 理解 小学教育
  • 简介:这份报纸论述处理鞠躬的效果的试验性的调查的结果悬于发货的数量上的延期在在常规头波浪进展的轮船的情况下在前甲板上流水。执行这调查,一系列免费跑的测试在使用一艘多种用途的货物轮船的一个试验性的模型确定的常规波浪被进行装运水的数量。测试在五个弓上被执行悬于有波长和轮船的几联合的变体加速条件。装运水的数量被象波长,轮船速度,和鞠躬形状那样的一些参数以overhang扩展影响,这被观察。结果显示出overhang延期的重要影响,它与鞠躬闪光形状被联系,在水发货的出现上。这些结果包含联合到来的常规波浪和模型速度。

  • 标签: 船艏 水量 装运 实验模型 运行试验 多用途货船
  • 简介:Shipcollisionaccidentsarerareeventsbutposehugethreattohumanlives,assets,andtheenvironment.Manyresearchershavesoughtforeffectivemodelsthatcomputeshipstochasticresponseduringcollisionsbyconsideringthevariabilityofshipcollisionscenarioparameters.However,theexistingmodelswerelimitedbythecapabilityofthecollisioncomputationalmodelsanddidnotcompletelycapturecollisionscenario,andmaterialandgeometricuncertainties.Inthispaper,anovelframeworktoperformancecharacterisationofshipsincollisioninvolvingavarietyofstrikingshipsisdeveloped,bycharacterisingthestructuralconsequenceswithefficientresponsemodels.Adouble-hulloilcarrierischosenasthestruckshiptodemonstratetheapplicabilityoftheproposedframework.Responsesurfacetechniquesareemployedtogeneratethemostprobableinputdesignsetswhichareusedtosampleanautomatedfiniteelementtooltocomputethechosenstructuralconsequences.Theresultingpredictor-responserelationshipsarefittedwithsuitablesurrogatemodelstoprobabilisticallycharacterisethestruckshipdamageundercollisions.Asdemonstratedinthispaper,suchmodelsareextremelyusefultoreducethecomputationalcomplexityinobtainingprobabilisticdesignmeasuresforshipstructures.Theproposedprobabilisticapproachisalsocombinedwithavailablecollisionfrequencymodelsfromliteraturetodemonstratetherisktolerancecomputations.

  • 标签: SHIP COLLISION HULL DAMAGE NUMERICAL simulation
  • 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:把在一般计算液体动力学代码FLUENT6.3.26嵌入的二阶段的模型基于液体的体积,粘滞有在一艘可伸缩模型的KRISO容器轮船(KCS)附近的免费表面的流动数字地首先被模仿。然后与一个rigid-lid-free-surface方法,在水下流动地基于混合被计算模仿的多相的模型冒泡在KCS壳附近醒来。二方程的骚乱模型和雷纳兹应力建模的可实现的k-被用来在轮船上分析骚乱模型的效果冒泡醒来。空气乘火车模型,它相对免费表面的正常速度坡度,和解决的方法被品质上验证合理计算结果。

  • 标签: 数值模拟 香槟 船舶 计算流体动力学 湍流模型 雷诺应力模型
  • 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
  • 简介:Inthisarticle,anewacoustictesttechniqueusingtowedmodelwasintroducedtostudyflownoisecausedbyasurfaceship.Theprojectofmodeltestwasbeproperlydesignedforacousticsignalcollectingandwiththehelpofappropriatedataprocessingmethoddifferentkindsofacousticsourcescouldbesuccessfullyidentified.Alotofworkaboutfuidnoisecouldbecarriedonwiththetowedmodel,andthenoisecorrespondingtolowfrequencywhichisespeciallyinterestedforitslongdistanceradiatingwithsmallattenuationcouldalsobestudiedinthisway.

  • 标签: 水动力学 流场 数值分析 模型
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  • 简介:Hydrodynamicoptimizationofthehullformscanberealizedthroughtheimplementationandintegrationofcomputationaltoolsthatconsistofahydrodynamicmodule,ahullsurfacerepresentationandmodificationmodule,andanoptimizationmodule.Inthepresentpaper,anewbulbousbowgenerationandmodificationtechniquehasbeendevelopedandintegratedintothehullsurfacerepresentationandmodificationmodule.Aradialbasisfunctionbasedsurrogatemodelisdevelopedtoapproximatetheobjectivefunctionsandreducethecomputingcost.Amulti-objectiveartificialbeecolonyoptimizationalgorithmisimplementedandintegratedintotheoptimizationmodule.Toillustratetheintegratedhydrodynamicoptimizationtools,acargoshipisoptimizedforreduceddrag.Theoptimalhullformsobtainedarethenvalidatedcomputationallyandexperimentally.Validationresultsshowthatthepresenttoolscanbeusedefficientlyandeffectivelyinthesimulationbaseddesignofthehullformsforreduceddrag.

  • 标签: 船型优化 阻力 货船 优化模块 流体动力学 计算工具
  • 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:计划的三维的设计和轮船建设在这篇论文被描述的建模集成轮船的虚拟轮船汇编的一个新方法。模拟基于虚拟轮船汇编进程当模特儿的一个工作流模型也被建立;而且,在三维的设计和轮船建设计划的轮船之间的信息转变的一个方法被提出。满足在轮船在不同系统之间分享的信息的要求虚拟汇编,一个模拟数据库被使用软件工程设计方法和关系数据模型创造。用这个数据库的应用程序,轮船的信息三维的设计,计划的构造,和虚拟汇编能集成于一个系统。随后,这个新方法作为一个工具被使用模仿一艘轮船的虚拟集会,并且结果保证它的合理性和可靠性。

  • 标签: 集成建模方法 船舶建造 虚拟装配 关系数据模型 三维设计 信息共享
  • 简介:Atheoreticalmodelwasusedtoinvestigatetheinfluencesofenvironmentalandtopographicparametersontheatmosphericthree-layerinternalshipwaves.TheresultsshowthatboththewavelengthandthewedgeangledecreasewithanincreaseintheScorerparameter,andtherateofchangesinthewavelengthandwedgeanglearealsoalike.Theresultsalsoshowthatthewedgeangledecreaseswithanincreaseinthewidthofmountain,butthewavelengthvarieslittlewithit.Itissuggestedthatthewedgeangleisdeterminedbytheratioofthewavelengthtothescaleofthemountain.Besides,numericalsensitivityexperimentswereperformedtotesttheformernumericalexperiments.Thesimulatedresultsareconsistentwiththeanalyticalresults.

  • 标签: 参数设计 地形 大气 波浪
  • 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