简介：

简介：IceformationintheharboursinarcticregionsuchasinFinlandisaprobleminwintertimes.Theairbubblersareoftenusedforcontrollingthegrowthoficeneartheharbourpierwalls.Thispapergivesanin-depthdescriptionoftheharbouriceproblemandtheapplicabilityofthebubblers.Anumericalmethodofflowandheat-transferisusedtopredicttheeffectivenessoftheairbubblersincontrollingtheiceaccumulationintheharbours.Empiricalmodelsofformattingandmeltingtheicearepresentedandusedinthenumericalsolutions.Itshowsthatthenumericalmethodcanrealisticallypredicttheice-meltingeffectoftheairbubblers.

简介：Recentobservationssupportanemergingparadigmthatclimatevariabilitydominatesnutrientenrichmentincostaleco-systems,whichcanexplainseasonalandinter-annualvariabilityofphytoplanktoncommunitycomposition,biomass(Chl-a),andprimaryproduction(PP).Inthispaper,wecombinedobservationandmodelingtoinvestigatetheregulationofphytoplanktondynamicsinChesapeakeBay.Theyearwechoseis1996thathashighriverrunoffandisusuallycalleda’wetyear’.A3-Dphysical-biogeochemicalmodelbasedonROMSwasdevelopedtosimulatetheseasonalcycleandtheregionaldistributionsofphytoplanktonbiomassandprimaryproductioninChesapeakeBay.Basedonthemodelresults,NO3presentsastrongcontrasttotherivernitrateloadduringspringandthehighestconcentrationinthebayreachesaround80mmolNm-3.Comparedwiththenormalyear,phytoplanktonbloominspringof1996appearsinlowerlatitudeswithahigherconcentration.Quantitativecomparisonbetweenthemodeledandobservedseasonalaverageddissolvedinorganicnitrogenconcentrationsshowsthatthemodelproducesreliableresults.Thecorrelationcoefficientr2forallquantitiesexceeds0.95,andtheskillparameterforthefourseasonsisallabove0.95.

简介：Underwatervehicleplaysanimportantroleinoceanengineering.Depthcontrolbyfinisoneofthedifficultiesforunderwatervehicleinmotioncontrol.Depthcontrolisindirectduetothefreedomcouplingbetweentrimandaxialmotion.Itincludesthemethodofdynamicanalysisandlift-resistance-coefficientexperimentandtheoryalgorithm.Byconsideringthecurrentspeedanddepthdeviation,comprehensiveinterpretationisusedinobject-planninginstruction.Expecteddepthistransformedintoexpectedtrim.Dynamicoutputfluctuationcanbeavoided,whichiscausedbylinearmappingofdeviation.Itissteadyandaccurateforthemotionofcontrolledunderwatervehicles.Thefeasibilityandefficiencyofthecontrolmethodaretestifiedinthepoolandnaturalareaforexperiments.

简介：Inthisstudy,theentiremitochondrialDNA(mtDNA)controlregion(CR)ofPholisfangiwasamplifiedviapolymerasechainreactionfollowedbydirectsequencing.ThelengthofthemtDNACRconsensussequenceofP.fangiwas853bpinlength.Inaccordancewiththerecognitionsitesaswerepreviouslyreportedinfishspecies,themtDNACRsequenceofP.fangicanbedividedinto3domains,i.e.,theextendedterminalassociatedsequence(ETAS),thecentralconservedsequenceblock(CSB),andtheCSBdomain.Inaddition,thefollowingstructureswereidentifiedinthemtDNACRsequenceofP.fangi:2ETASsintheETASdomain(TASandcTAS),6CSBsinthecentralCSBdomain(CSB-FtoCSB-A),and3CSBsintheCSBdomain(CSB-1toCSB-3).ThesedemonstratedthatthestructureofthemtDNACRofP.fangiwassubstantiallydifferentfromthoseofmostotherfishspecies.ThemtDNACRsequenceofP.fangicontainedoneconservedregionfrom656bpto815bp.Similartomostotherfishspecies,P.fangihasnotandemrepeatsequencesinitsmtDNACRsequence.PhylogeneticanalysisbasedonthecompletemtDNACRsequencesshowedthattherewerenogeneticdifferenceswithinP.fangipopulationsofthesamegeographicaloriginandbetweenP.fangipopulationsofdifferentgeographicalorigins.

简介：AnobviousmotivationofthispaperistoexaminetheeffectivenessofthelateralvibrationcontrolofajackettypeoffshoreplatformwithanAMDcontroldevice,inconjunctionwithH2controlalgorithm,whichisanoptimalfrequen.cydomaincontrolmethodbasedonminimizationofH2normofthesystemtransferfunction.Inthisstudy,theoffshoreplatformismodelednumericallybyuseofthefiniteelementmethod,insteadofalumpedmassmodel.Thisstructuralmodelislatersimplifiedtobesingle-degree-of-freedom(SDOF)systembyextractingthefirstvibrationmodeofthestruc.ture.Thecorresponding″generalized″waveforceisdeterminedbasedonananalyticalapproximationofthefirstmodeshapefunction,thephysicalwaveloadingbeingcalculatedfromthelinearizedMorisonequation.Thisapproachfacilitatesthefilterdesignforthegeneralizedforce.Furthermore,thepresentpaperalsointendstomakenumericalcompari.sonbetweenH2activecontrolandthecorrespondingpassivecontrolusingaTMDwiththesamedeviceparameters.

简介：ThereisalownutrientlevelintheAoshanBay.InJune1999,thechemicaladjustmentandcontrolexperimentwasmadeintheAoshanBay.Followingtractsinvestigationwascarriedoutbeforetheexperimentandonthe1st,2nd,4th,5th,6thand45thday/aftertheexperiment.Whilethevarianceofamountofphytoplankton,thereplacementofsuperiorspeciesandthespeciescompositionofphytoplanktonwereresearched.TheresultsshowthattheamountofphytoplanktonintheAoshanBayrisesgraduallyaftertheexperiment.CeratiummacrocerosCleveofpyrophytawasthedominantspeciesbeforetheexperiment,itsdominantindexwas37.7%.Sixdaysaftertheexperiment,itsdominantindexdroppedto17.6%.MeanwhilethedominantindexofAsterionellajaponicsCleverosefrom7.1%to39.2%,itbecamethefirstdominantspecies.Forty-fivedaysaftertheexperiment,theamountofphytoplanktonintheAoshanBaywas5.15to137.32timesmorethanthatin1997.

简介：ByimplementingtheARGOprogram,alargenumberofT-Sprofilescanbeobservedintheworldocean.However,itisverydifficulttoexaminechangesofthesensitivityofthesensorsequippedattheARGOfloats,becauseitisdifficulttounderstandtheirconditionintheseaandthereliabilityofthedata.Qualitycontrolmustbedoneinordertoavoidthewrongconclusiondeducedfromthewrongdata.OneoftherealisticmethodsforqualitycontroloftheARGOdataisthecomparisonwiththelocalclimatology.HighqualityclimatologicalT-SmodelsinnorthwestPacifichavebeenbuiltbasedontheNansenbottledataandCTDdataforthequalitycontrolinNMDIS.ThemodelsareusedtochecktheARGOdatainthisareaandhavegotgoodresult.

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

简介：Astheexplorationandexploitationofoilandgasproliferatethroughoutdeepwaterarea,therequirementsonthereliabilityofdynamicpositioningsystembecomeincreasinglystringent.Thecontrolobjectiveensuringsafetyoperationatdeepwaterwillnotbemetbyasinglecontrollerfordynamicpositioning.Inordertoincreasetheavailabilityandreliabilityofdynamicpositioningcontrolsystem,thetripleredundancyhardwareandsoftwarecontrolarchitecturesweredesignedanddevelopedaccordingtothesafespecificationsofDP-3classificationnotationfordynamicallypositionedshipsandrigs.Thehardwareredundantconfigurationtakestheformoftriple-redundanthotstandbyconfigurationincludingthreeidenticaloperatorstationsandthreereal-timecontrolcomputerswhichconnecteachotherthroughdualnetworks.Thefunctionofmotioncontrolandredundancymanagementofcontrolcomputerswereimplementedbysoftwareonthereal-timeoperatingsystemVxWorks.Thesoftwarerealizationoftaskloosesynchronization,majorityvotingandfaultdetectionwerepresentedindetails.Ahierarchicalsoftwarearchitecturewasplanedduringthedevelopmentofsoftware,consistingofapplicationlayer,real-timelayerandphysicallayer.ThebehavioroftheDP-3dynamicpositioningcontrolsystemwasmodeledbyaMarkovmodeltoanalyzeitsreliability.Theeffectsofvariationinparametersonthereliabilitymeasureswereinvestigated.Thetimedomaindynamicsimulationwascarriedoutonadeepwaterdrillingrigtoprovethefeasibilityoftheproposedcontrolarchitecture.

简介：Inthisstudy,theseismicresponsecontrolofoffshoreplatformstructureswithShapeMemoryAlloy(SMA)dampersisinvestigated.AnewSMAdamperanditsrestoringforcemodelareintroducedforthecalculationofseismicresponsereduction.Basedonanactualplatformstructureanditsmechanicalmodel,theparameterswhichmayaffecttherateofshockabsorptionareanalyzed,suchasthenumber,positionandcharacteristicsoftheSMAdampersandtheconditionofthesitewheretheplatformislocated.TheresultsshowthattheSMAdamperisaneffectivecontroldeviceforoffshoreplatformsandsatisfactorycontrolcanbeachievedbyproperselectionoftheparameters.

简介：Thispaperdescribesthedischargecontroltechniqueonboundaryusedintwomodels,oneisthemodelofhotwaterdrainninginDayawanNyclearPowerPlant,Guangdong,andtheotheristhemodelfortrainhingthesandbarattheGuanheEstuary,Jiangsu.Manyyearsofapplicationshowsthatthistechniquehastheadvantagesofgoodreliability,repeatabilityandvalidity.Thespeedometerofhydrogenbubbleisalsointroducedinthispaper.Thedevicecandisplayandstoretracinglinesinacomputer,andhelpoperatorstoobtainthevalueanddirectionoftransientvelocityofanonsteadycurrent,thus,theproblemofmeasurmentoflowcurrentvelocityintidalmodeltestsissolvedandtheautomationofthemeasurementofcurrentvelocityisrealized.

简介：Anoptimalactiveslidingmodecontrollerwithspecifieddecayratedesignisproposedtocontrolthewave-inducedoffshorejacket-typeplatformwithactivemassdamper(AMD).IrregularwaveloadingisapproximatedbyfinitesumsofFourierseries,anditsdynamiccharacteristicsaregovernedbyanexosystemderivedfromthelinearizedMorisonequation.Theoffshoreplatformsystemisfirstdecomposedintotwovirtualsubsystemsbasedonalineartransformation.ByconsideringthevelocityofAMDasavirtualcontrolforceforthefirstsubsystem,theoptimalvirtualcontrollerisderived.Furthermore,anoptimalslidingmodesurfacewithspecifieddecayrateisproposed.Then,theactiveslidingmodecontrollerisdesignedtoensurethatthestatetrajectoriesreachtheslidingsurfaceinfinitetimeandremainonitthereafter.Numericalsimulationisemployedtoverifytheeffectivenessoftheproposedapproach.

简介：Inthispaper,arobustpathfollowingcontrollawisproposedforadeep-seamannedsubmersiblemaneuveringalongapredeterminatedpath.DevelopedinChina,thesubmersibleisunderactuatedinthehorizontalplaneinthatitisactuatedbytwoperpendicularthrustsinthisplane.Theadvancednon-singularterminalslidingmode(NTSM)isimplementedforthedesignofthepathfollowingcontroller,whichcanensuretheconvergenceofthemotionsysteminfinitetimeandimproveitsrobustnessagainstparametricuncertaintiesandenvironmentaldisturbances.Intheprocessofcontrollerdesign,theclose-loopstabilityisconsideredandprovedbyLyapunov'sstabilitytheory.Withtheexperimentaldata,numericalsimulationsareprovidedtoverifythecontrollawforpathfollowingofthedeep-seamannedsubmersible.

简介：这份报纸涉及搬到领导人追随者形成的多重underactuated表面容器的形成控制问题。形成被追随者完成追踪相对领导人定义的一个虚拟目标。追踪法律的一个柔韧的适应目标被使用神经网络和backstepping技术建议。建议控制计划的优点是不明确的非线性的动力学由Coriolis/centripetal力量引起了，非线性的抑制，从环境的unmodeled水动力学和骚乱能被补偿由在线学习上。把分析基于Lyapunov，追踪的错误集成到起源的一位小邻居的建议控制器保证。模拟结果表明控制策略的有效性。

简介：作者由1的计算在溢出的特征发现了大差别)为用SWMM的下水道系统的溢出的拦截体积建模哪个从降雨考虑流量和污染物质并且2)总共的拦截体积流动在一个调查地点。在CSOsshowed的调查点的拦截的率更高比SSD珍视。在由与降雨认为流出论坛的特征是下水道系统的溢出的合适的管理计算溢出的拦截数量以后，基于当模特儿收到的水质，由为在从unprocessed与分泌物相比拦截流动的特定的数量以后的分泌物的82.9%-94.0%的BODdecreased溢出，是清楚的。

简介：Thispaperpresentsanextendedmodelpredictivecontrollerformaximizingtheabsorbedpowerofapointabsorberwaveenergyconverter.Owingtothegreatinfluenceofcontrollerparametersupontheabsorbedpower,theoptimizationoftheseparametersiscarriedoutforthefirsttimebyafireflyalgorithm(FA).Error,thedifferencebetweenoutputvelocityofbuoyandinputwavespeedwhichleadstopowermaximizationintheoptimizedMPCiscomparedwiththeclassicalMPC.Simulationresultsindicatethatgiventhehighaccuracyandacceptablespeedofthealgorithm,itcanadjusttheparametersofthecontrollertothepointwheresystemerrordecreasedeffectivelyandtheabsorbedenergyincreasedabout4MW.

简介：ImmersedtunnelisanimportantpartoftheHongKong–Zhuhai–MacaoBridge(HZMB)project.Inimmersedtunnelfloating,translationwhichincludesstraightandtransversemovementsisthemainworkingmode.Todecidethemagnitudeanddirectionofthetowingforceforeachtug,aparticleswarm-basedtranslationcontrolmethodispresentedfornon-powerimmersedtunnelelement.Asortoflinearweightedlogarithmicfunctionisexploitedtoavoidweaksubgoals.Insimulation,theparticleswarm-basedcontrolmethodisevaluatedandcomparedwithtraditionalempiricalmethodinthecaseoftheHZMBproject.Simulationresultsshowthatthepresentedmethoddeliversperformanceimprovementintermsoftheenhancedsurplustowingforce.

简介：Afullycoupled6-degree-of-freedomnonlineardynamicmodelispresentedtoanalyzethedynamicresponseofasemi-submersibleplatformwhichisequippedwiththedynamicpositioning(DP)system.Inthecontrolforcedesign,adynamicmodelofreferencelineardriftfrequencyinthehorizontalplaneisintroduced.Thedynamicsurfacecontrol(DSC)isusedtodesignacontrolstrategyfortheDP.Comparedwiththetraditionalback-steppingmethods,thedynamicsurfacecontrolcombinedwithradialbasisfunction(RBF)neuralnetworks(NNs)canavoiddifferentiatingintermediatevariablesrepeatedlyineverydesignstepduetotheintroductionofafirstorderfilter.LowfrequencymotionsobtainedfromtotalmotionsbyalowpassfilterarechosentobetheinputsfortheRBFNNswhichareusedtoapproximatethelowfrequencywaveforce.Consideringthepropellers’wearandtear,theeffectoffilteringfrequenciesforthecontrolforceisdiscussed.Basedonpowerconsumptionsandpositioningrequirements,theNNcentersaredetermined.Moreover,theRBFNNsusedtoapproximatethetotalwaveforcearebuilttomonitorthedisturbances.WiththeDPassistance,theresultsoffullycoupleddynamicresponsesimulationsaregiventoillustratetheeffectivenessoftheproposedcontrolstrategy.