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简介：Inordertoimprovetheabilitytolocalizeasourceinanuncertainacousticenvironment,aBayesianapproach,referredtohereasBayesianlocalizationisusedbyincludingtheenvironmentintheparametersearchspace.Geneticalgorithmsareusedfortheparameteroptimization.Thismethodintegratestheaposteriorprobabilitydensity(PPD)overenvironmentalparameterstoobtainasequenceofmarginalprobabilitydistributionsoversourcerangeanddepth,fromwhichthemost-probablesourcelocationandlocalizationuncertaintiescanbeextracted.Consideringthattheseabeddensityandattenuationarelesssensitivetotheobjectivefunctionofmatchedfieldprocessing,weutilizetheempiricalrelationshiptoinvertthoseparametersindirectly.ThebroadbandsignalsrecordedbyaverticallinearrayinaYellowSeaexperimentin2000areprocessedandanalyzed.Itwasfoundthat,theBayesianlocalizationmethodthatincorporatestheenvironmentalvariabilityintotheprocessor,madeitrobusttotheuncertaintyintheoceanenvironment.Inaddition,usingtheempiricalrelationshipcouldenhancethelocalizationaccuracy.

简介：Inthepaper,theWKBZnormalmodeapproachhasbeenappliedtothepropagationofthepulsedenergyandwaveforminoceanchannels.Thenumericalresultsintwodifferentchannelsaregiven.ComparisonbetweentheWKBZandconventionalnormalmodecodesshowsthattheWKBZmodeapproachisafastandaccuratemethodandtherunningtimebytheWKBZapproachisreducedbyabouttwoordersofmagnitude.

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简介：贝叶斯的匹配的地处理的一条途径(MFP)在不明确的海洋environment.In被讨论这条途径，无常知识被建模，数组收到的空间、时间的数据是充分used.Therefore，为MFP的机制是found.which很好联合不明确的领域processing.By的基于模型、数据驱动的方法理论推导，模拟分析和在海的试验性的数组数据的确认，我们发现那(1)贝叶斯的匹配的领域pr的基本部件

简介：Theauthorshaveinventedtheuniqueoceanwavepowerstation,whichiscomposedofthefloatingtypeplatformwithapairofthefloatsliningupattheintervalofonewavepitchandthecounter-rotatingtypewavepowerunit,itsrunnersaresubmergedintheseawateratthemiddlepositionoftheplatform.Suchprofilesmaketheflowvelocityattherunneristwicefasterthanthatofthetraditionalfixed/caissontypeOWC,ontheidealflowconditions.Besides,therunnerscounter-rotatetheinnerandtheouterarmaturesofthepeculiargenerator,respectively,andtherelativerotationalspeedisalsotwicefasterthanthespeedofthesinglerunner/armature.Suchcharacteristicsmaketherunnerdiameterlarge,namelytheoutputhigher,asrequested,becausethetorqueofthepowerunitneveractonthefloatingtypeplatform.Atthepreliminaryreseach,thispaperverifiestogetthepowerusingaWellstypesinglerunnerinstalledinthemodelstation.Therunnertakestheoutputwhichisaffectedbytheoscillatingamplitudeoftheplatform,therotationalspeedandtheinertiaforceoftherunner,etc.

简介：TostudythespatialdifferenceofoceanambientnoiseinoffshoreChinaandrevealitsgenerationmechanism,thedifferencebetweenthenoiselevel(NL)oftwostationsiscomparedbasedonlong-termobservationdatacollectedinthesameseason.Consideringtheinfluenceofunderwateracousticchannelsandthecharacteristicsofnoisesources,thetransmissionlosslevel(TL)fromtheportshipnoisesourcestothemeasuringstationisanalyzedanditshowsastrongcorrelationbetweenthetransmissionlossdifference(TLD)andnoiseleveldifference(NLD)atthebandof50-500Hz.Atthesametime,theanalysisofshipnoisesourcelevel(SL)presentsadifferenceabout20dBbetweenthetwoports,correspondingtothevariationoftheshipdensitybeforeandduringthefishingmoratorium.Theresultsprovethattheambientnoiseiscloselyrelatedtoshipnoisesourcesatthisfrequencyband,andthenoisedifferencebetweenthetwostationsresultsfromthetransmissionlossandtheshipnoisesources.

简介：Consideringtheuncertaineffectsoftemporalandspatialchangesinthemarineenvironmentontheunderwateracousticenvironment,weestablishedanocean-acousticcouplednumericalmodelandperformedaparallelcalculation.Thismodelincorporatedacousticcalculationsintothedynamicocean,therebyachievingadynamicforecastingandassessmentoftheacousticenvironment.Furthermore,weadoptedtheensemblepredictionmethodtopredicttheverticalstructureoftemperatureinaclassiccross-section,thesoundspeedofthecross-sectionoftheinvestigatedseaarea,andtransmissionlosses.Wegavethepredictionerrorsofthesoundspeedprofileaswellasthe90%probabilityintervaloftransmissionlossesandtheuncertaintyhistogramsofthesoundspeeds,transmissionlosses,andsonarrangesatdifferentdepthsandfrequencies.Theresultsreflectedtheinfluenceofmarinetemporalandspacialvariationsontheuncertaintiesoftheunderwateracousticenvironment,andtheresultsalsoquantifiedtheuncertaintiesoftheunderwateracousticenvironmentparameters.Theexperimentalresultsindicatethatthemethodusedinthisstudyisabletodelineateandquantifytheuncertaintiesoftheunderwateracousticenvironmentcausedbymarinedynamicchanges.

简介：Byinvestigatingtheeffectsondeepoceanambientnoiseoftyphoon'KAI-TAK'whichpassedthenorthareaoftheSouthChinaSea,itisshownthatthewindspeed,therainfallintensityandthelongwaveswellcausedbytyphoonaffecttheoceanambientnoisesignificantly.Thecorrelationbetweentheoceanambientnoiseandthewindspeedduringthetyphoonismuchbetterthanthatinthenon-typhoonperiodinthesameBeaufortscale.Analysisofthecorrelationbetweenthe415hoceanambientnoisemeasureddataandwindspeedshowsthat,whenthefrequencyisgreaterthan300Hz,thecorrelationcoefficientbetweentheoceanambientnoiseandthewindspeedisgreaterthan0.5,achievingamoderatecorrelation;whenthefrequencyisgreaterthan630Hz,thecorrelationcoefficientisbetween0.8and0.9,achievingahighdegreeofcorrelation.Thecorrelationbetweentheoceanambientnoiseandthewindspeedisbetterthanthatbetweentheoceanambientnoiseandthesignificantwaveheightwhenthefrequencyisgreaterthan300Hz.Thecorrelationbetweentheoceanambientnoiseandthewindspeedininfrasonicbandfrom10Hzto20HzispoorintheSouthChinaSea,becausetheshippingisbusyinthisseaareaandtheoceanambientnoiseiscontaminatedbytheshipnoiseevenduringthetyphoon.

简介：Inthispaper,aresearchontheproblemofmultiplesolutionsofthethree-coefficientlow-spectrummodelforthequasi-geostrophicoceancurrentequationwithforcinganddissipationtermsiscarriedout.Thestateoftheoceancurrentunderwindconditionssuchasthoseoftyphoonisdiscussedcarefullyandtherela-tionsbetweenthemultiplesolutionsandthecoefficientsRandεareanalyzed.Itisseenthatinanapproxi-matetriangularregionwiththeRossby-coefficientRlessthan0.5,andthefriction-coefficientεlessthan0.22,thereexistthreeequifibriumsolutions,amongwhichtwoarestableandoneisunstable.Fortheformer,thecoefficientAorBintheexpansionisratherlarge,whileforthelatter,AorBisrelativelysmall.TheyrespectivelyimplyhowmuchtheoceanenergyisfedbackfromthewindstressandthesolutionwithalargeAismuchmorestablethanthatwithalargerB.

简介：Inthispaper,theoceanacousticchannelisconsideredasatime-variantchannel.Inordertoanalysetheconjointtime-shift-fre-quency-delaydistributionorthefadingandspreadstatisticalcharacteristicsofthechannel.TheTDWVS(TwoDimensionalWigner-VilleSpectrum)ofthetime-variantchannelisdefined.TherelationbetweentheWVS(Wigner-VilleSpectrum)oftheinputandtheoutputofthechannelisdiscussedandsomeexamplesforthespecificchannelareshown.Finally,theapplicationsonthedetectionofsignalsinnoiseusingtheWVSandTDWVSaregivenandtheadvantageisobvious,whenthedetectedsignalislinearfrequency-modulationsignal.