简介：Multi-directionalirregularwavesaresimulatedonthebasisofthegivendirectionalspectrumusingadoublesummationmodel,asingledirectionperfrequencymodelandasinglesummationmodel.Theirresultsarecompared.Itisshownthatthesingledirectionperfrequencymodelproposedinthispapercangeneratearealisticwavefield.Theeffectsofthemodelparametersonthesimulatedresultsarealsostudiedinthispaperandcorrespondingsuggestionsaregiven.

简介：Multi-componentmooringsystemsbecomewidelyusedindeepwaterposition-keepingofdrillingandproductionplatforms.However,versatilematerialsmakeitdifficulttodesignappropriatemooringlinesmadeofseveralsegments.Basedoncatenaryequationsofamulti-componentmooringlineataspecificwaterdepth,thispaperestablishesaminimummodelfordesigningthiskindoflines.ThemodelissolvedbyGeneticAlgorithmandMulti-ObjectivePlanningrespectively.Themodelisverifiedbyitsapplicationtoapracticalmooringdesignassignment-aquasi-staticanalysisforalargesemi-submersible.Theoptimalresultisfinallyobtainedwiththeaidofdesigngraphs.

简介：Multi-beamSonarandSide-scanSonarcompensateeachother.Inordertofullyutilizeallinformation,itisnecessarytofusetwokindsofimageanddata.Andtheimageco-registrationisanimportantandcomplicatedjobbeforefusion.Thispapersuggestscombiningbathymetricdatawithintensityimage,obtainingthecharacteristicpointsthroughtheminimalanglesoflines,andthendecidingthecorrespondingimagepointsbythemaximalcorrelatecoefficientinsearchingspace.Finally,thesecondorderpolynomialisappliedtothedeformationmodel.Aftertheimageshavebeenco-registered,Waveletisusedtofusetheimages.Itisshownthatthisalgorithmcanbeusedintheflatseafloorortheisotropicseabed.Verificationismadeinthepaperwiththeobserveddata.

简介：Thepurposeofthisstudyistoinvestigatetheeffectivenessofmulti-tunedmassdampers(MTMD)onmitigatingvi-brationofanoffshoreoilplatformsubjectedtooceanwaveloading.Anoptimaldesignmethodisusedtodeterminetheop-timaldamperparametersunderoceanwaveloading.TheforceonthestructureisdeterminedbyuseofthelinearizedMorisonequation.InvestigationonthedeckmotionwithandwithoutMTMDonthestructureismadeunderdesigncondi-tions.TheresultsshowthatMTMDwiththeoptimizedparameterssuppresstheresponseofeachstructuralmode.ThesensitivityofoptimumvaluesofMTMDtocharacteristicwaveparametersisalsoanalyzed.ItisindicatedthatasingleTMDonthedeckofaplatformcanhavethebestperformance,andthesmallthedampingvalueofTMD,thebetterthevibrationcontrol.

简介：Thispaperextendsapredictionmodelformulti-directionalrandomwavetransformationbasedonanenergybalanceequationbyMasewiththeconsiderationofwaveshoaling,refraction,diffraction,reflectionandbreaking.Thisnumericalmodelisimprovedby1)introducingWen'sfrequencyspectrumandMitsuyasu'sdirectionalfunction,whicharemoresuitabletothecoastalareaofChina;2)consideringenergydissipationcausedbybottomfriction,whichensuresmoreaccurateresultsforlarge-scaleandshallowwaterareas;3)takingintoaccountanon-lineardispersionrelation.PredictionsusingtheextendedwavemodelarecarriedouttostudythefeasibilityofconstructingtheAiHuayachtportinQingdao,China,withacomparisonbetweentwoportlayoutsindesign.Wavefieldsinsidetheportfordifferentincidentwavedirections,waterlevelsandreturnperiodsaresimulated,andthentwokindsofparametersarecalculatedtoevaluatethewaveconditionsforthetwolayouts.AnalysesshowthatLayoutIisbetterthanLayoutII.Calculationresultsalsoshowthattheharborwillbecalmfordifferentwavedirectionsunderthedesignwaterlevel.Onthecontrary,thewaveconditionsdonotwhollymeettherequirementsofayachtportforshipberthingundertheextremewaterlevel.Forsafetyconsideration,theelevationofthebreakwatermightneedtobeproperlyincreasedtopreventwaveovertoppingundersuchwaterlevel.Theextendednumericalsimulationmodelmayprovideaneffectiveapproachtocomputingwaveheightsinaharbor.

简介：-Measuringmulti-directionalwaveswiththewavegaugearrayisoneofthefundamentalandeasilyrealisedmethods.Inthispaper,thewavegaugearrayisdescribedandtheeffectsofthegaugespacing,thearrayorientations,etc.ofthethreearrayarrangements,i.e.,lineararray,T-typearrayandpentagonarray,ontheresolutionofthedirectionalspreadingofwaves,areinvestigatedexperimentally.Thisstudycanbeusedasareferenceintheexperimentalstudyandthefieldmeasurementofdirectionalwaves.

简介：Themodifiedhybridelementmethod(MHEM)isutilizedtopredictandanalyzewaveforcesonarbitrarilyshapedmultiplebodies.Thismethodcanbeappliedtowavesofallwaterdepths,i.e.shallow,intermediate,anddeepwaters,onslowlyvaryingseabed.TheMHEMemploystheICCGmethodtosaveCPUandstorage,thusthecomputationofwaveforcesforlargemulti-bodysystemscanbecarriedoutonmicrocomputers.Numericalresultsofthepresentmethodarecomparedwithexperimentaldataandothersolutions.ItisshownthattheMHEMprovidesmoreaccuratesolutionsofthewaveforcesthanothernumericalmethodsdo.Therefore,themethodologypresentedhereincanbeusedinthedesignofcoastalandoceanstructures.

简介：Anumericalsimulationandanexperimentalstudyonvortex-inducedmotion(VIM)ofanewtypeofdeepdraftmulti-columnsfloatingdrillingproduction,storageandoffloading(FDPSO)arepresentedinthispaper.Themaindimension,thespecialvariablecross-sectioncolumnandthecabinarrangementoftheoctagonalpontoonareintroducedbasedontheresult.Thenumericalsimulationisadaptedtostudytheeffectsofcurrentincidenceanglesandreducedvelocitiesonthisplatform'sswaymotionresponse.The300mwaterdepthequivalenttruncatedmooringsystemisadoptedforthemodeltests.Themodeltestsarecarriedouttocheckthereliabilityofnumericalsimulation.Theresultsconsistofsurge,swayandyawmotions,aswellasmotiontrajectories.Themaximumswayamplitudesfordifferenttypesofoffshoreplatformisalsostudied.Themainresultsshowthatthepeakfrequenciesofswaymotionunderdifferentcurrentincidenceanglesandreducedvelocitiesvaryaroundthenaturalfrequency.TheanalysisresultofflowfieldindicatesthatthechangeofdistributionofvortexinverticalpresentssignificantinfluencesontheVIMofplatform.ThetrendofswayamplituderatiocurveofthisnewtypeFDPSOdiffersfromtheothertypesofplatform.Under45°currentincidenceangle,theswayamplitudeofthisnewtypeofFDPSOismuchsmallerthanthoseofothertypesofoffshoreplatformat4.4≤Vr≤8.9.Thetypical'8'shapetrajectorydoesnotappearintheplatform'smotiontrajectories.

简介：Thispaperaddressesthemulti-faultdiagnosisproblemofthrustersandsensorsforautonomousunderwatervehicles（AUVs）.Traditionalsupportvectordomaindescription（SVDD）haslowclassificationaccuracyintheprocessofAUVmulti-faultpatternclassificationbecauseoftheeffectofsamplesparsedensityandtheunevendistributionofsamples,andsoon.Thus,afuzzyweightedsupportvectordomaindescription（FWSVDD）methodbasedonpositiveandnegativeclasssamplesisproposed.Inthismethod,thenegativeclasssampleisintroducedduringclassifiertraining,andthelocaldensityandtheclassweightareintroducedforeachsample.Toimprovethemulti-faultpatternclassifiertrainingspeedandfaultdiagnosisaccuracyofFWSVDD,amulti-faultmodeclassificationmethodbasedonahierarchicalstrategyisproposed.Thismethodaddsfaultcontaindetectionsurfaceforeachthrusterandsensortoisolatefaultcomponentsduringfaultdiagnosis.Byconsideringtheproblemofpatternclassificationforafuzzysample,whichmaybelocatedintheoverlappingareaofhyper-spheresormaynotbelongtoanyhyper-sphereintheprocessofmulti-faultclassificationbasedonFWSVDD,arelativedistancejudgmentmethodisgiven.Theeffectivenessoftheproposedmulti-faultdiagnosisapproachisdemonstratedthroughwatertankexperimentswithanexperimentalAUVprototype.

简介：在现在的文章，我们介绍产品每天由海洋科技(KIOST)的朝鲜研究所产生了的高分辨率海表面温度(SST)。SST产品包括1km分辨率的八小时、每日的平均SST数据由数据的四个集合组成，并且基于四红外线(红外)卫星SST数据由先进很高的分辨率辐射计(AVHRR)获得了，中等分辨率成像分光辐射函数(MODIS)，多功能的运输Satellites-2(MTSAT-2)成像器和气象学的成像器，扫描辐射计2的先进微波(AMSR2)获得的二微波辐射计SST，和WindSAT与(MI)在原处温度这些输入卫星并且在原处，SST数据被使用最佳的插值(OI)合并算法。卫星并且在原处的root-mean-square-errors(RMSE)数据在OI算法被用作weighting价值。作为一个飞行员产品，四个SST数据集合每天从1月被产生到2013年12月。在在系在的浮标测量的SST和每天吝啬的KIOSTSST之间的比较，估计的RMSE是0.71yconcentr睰?睰吗？？

简介：Deep-waterregionsoftenhavewindsfavorableforoffshorewindturbines,andfloatingturbinescurrentlyshowthegreatestpotentialtoexploitsuchwinds.Thisworkestablishedproperscalinglawsformodeltests,whichwerethenimplementedintheconstructionofamodelwindturbinewithoptimallydesignedblades.Theaerodynamic,hydrodynamic,andelasticcharacteristicsoftheproposednewmulti-columntension-leg-typefloatingwindturbine(WindStarTLPsystem)wereexploredinthewavetanktestingofa1:50scalemodelattheStateKeyLaboratoryofOceanEngineeringatShanghaiJiaoTongUniversity.Testswereconductedunderconditionsofstillwater,whitenoisewaves,irregularwaves,andcombinedwind,wave,andcurrentloads.Theresultsestablishedthenaturalperiodsofthemotion,damping,motionresponseamplitudeoperators,andtendontensionsoftheWindStarTLPsystemunderdifferentenvironmentalconditions,andthuscouldserveasareferenceforfurtherresearch.

简介：Thispaperpresentsacoupleddynamicresponseanalysisofamulti-columntension-leg-typefloatingwindturbine(WindStarTLPsystem)undernormaloperationandparkedconditions.Wind-onlyloadcases,wave-onlyloadcasesandcombinedwindandwaveloadcaseswereanalyzedseparatelyfortheWindStarTLPsystemtoidentifythedominantexcitationloads.ComparisonsbetweenanNRELoffshore5-MWbaselinewindturbineinstalledonlandandtheWindStarTLPsystemwereperformed.Statisticsofselectedresponsevariablesinspecifieddesignloadcases(DLCs)wereobtainedandanalyzed.ItisfoundthattheproposedWindStarTLPsystemhassmalldynamicresponsestoenvironmentalloadsanditthushasalmostthesamemeangeneratorpoweroutputunderoperatingconditionsastheland-basedsystem.Thetensionmooringsystemhasasufficientsafetyfactor,andtheminimumtendontensionisalwayspositiveinallselectedDLCs.Theratioofultimateloadofthetowerbasefore-aftbendingmomentfortheWindStarTLPsystemversustheland-basedsystemcanbeashighas1.9inalloftheDLCsconsidered.TheseresultswillhelpelucidatethedynamiccharacteristicsoftheproposedWindStarTLPsystem,identifythedifferenceinloadeffectbetweenitandland-basedsystems,andthusmakerelevantmodificationstotheinitialdesignfortheWindStarTLPsystem.

简介：浮标系统的推广是为浮标系统的操作的最重要的过程之一。在现在的学习，包含表面浮标的一个单个点的绳索浮标系统，有部件的电报片断，锚被使用多身体动力学等等建模方法。运动方程在分离节点描述和充分笛卡儿的坐标被开发。然后数字的方法被用来解决平常的微分方程，当锚从董事会正在扔时，动力学模拟被完成。没有电流并且与在浮标系统的电流的不同节点的轨道和速度被获得。电缆线的每部分的短暂紧张力量在推广的进程被分析。当锚正在摸海床和力量将与不同漂浮配置改变的最大的紧张时，数字结果显示短暂收费载重增加到山峰价值。这个工作对浮标系统计划的设计和推广有用。

简介：Thecoupledhull,mooringandriseranalysistechniquesintimedomainarewidelyrecognizedastheuniqueapproachtopredicttheaccurateglobalmotions.However,thesecomplexissueshavenotbeenperfectlysolvedduetoalargenumberofnonlinearfactors,e.g.forcesnonlinearity,mooringnonlinearity,motionnonlinearityandsoon.Thispaperinvestigatesthecoupledeffectsthroughthenumericaluncoupledmodel,mooringcoupledmodelandfullycoupledmodelaccountingmooringandrisersbasedonanoveldeepdraftmulti-sparwhichisespeciallydesignedfordeepwaterin2009.Thenumericalstatic-offset,free-decay,wind-actiontestsareexecuted,andfinallythreehourssimulationsareconductedunder100-yearreturnperiodofGOMconditionsinvolvingwave,windandcurrentactions.Thedampingcontributions,responsecharacteristicsandmooringlinetensionsareemphaticallystudied.