简介：通过采用遗传算法优化神经网络初始权值的方法,将GA算法与BP神经网络有机结合,应用于海底底质分类。基于多波束测深系统获取的反向散射强度数据,应用改进的BP神经网络分类方法,实现对海底基岩、砾石、砂、细砂和泥等底质类型的快速、准确识别。通过实验比较,GA-BP神经网络分类精度明显高于BP神经网络,证明了该方法的有效性和可靠性。

简介：Aninnovativefloatingmooringsystemwithtwoormoreindependentfloatingmooringplatformsinthemiddleandonerigidplatformoneachsideisproposedforimprovingefficiencyandsafetyinshallowwater.Forthisnewsystem,mostofcollisionenergyisabsorbedthroughthedisplacementoffloatingplatforms.Inordertoillustratethevalidityofthesystem,aseriesofmodeltestswereconductedatascaleof1:40.Thecoupledmotioncharacteristicsofthefloatingmooringplatformswerediscussedunderregularandirregularwaves,andtheinfluencesofwavedirectionandothercharacteristicsondynamicresponseofthesystemwereanalyzed.Theresultsshowthatthemooringsystemissafestat0°ofwaveincidentangle,whereasthemostdangerousmooringstateoccursat90°ofwaveincidentangle.Motionresponsesincreasewiththeincreaseofwaveheight,butarenotlinearlyrelatedtochangesinwaveheight.

简介：Inthispaper,theunderwatervehicle,slingandthemothershipareconsideredasasinglede-greeoffreedomsystemconnectedbyaspring.Throughtheanalysisofthissystem,aphysicalmodelises-tablished,whichdescribesthemotionofthevehiclecausedbytheshipmotionandwavemotion.Furthermore,amathematicalmodelbasedonthisphysicalmodelisobtained,andanumericalsolutionprogramismade.Asanexample,apracticallaunchandrecoverysystemforanunderwaterrobotiscalcu-latedbyuseoftheprogram.andthemotiontrackoftherobotisobtained.

简介：为了能够客观地对海水水质进行综合评价，在分析人工神经网络概念和原理的基础上，从阈值角度出发，通过对各类海水水质污染指标浓度生成样本的方法，生成了适用于BP人工神经网络模型训练的样本，并应用基于误差反向传播原理的前向多层神经网络，建立了用于海水水质评价的BP人工神经网络模型。将该模型用于渤海湾近岸海域水环境评价，通过模型的计算，得到该海域的水质类别。结果表明，2004-2007年，渤海湾近岸海域污染指标总体上在河流丰水期时比枯水期时高，2005年和2006年污染较为严重，2007年有所好转。经训练的评价模型应用于实例的评价结果表明，该模型设计合理、泛化能力强，对海水水质评价具有较好的客观性、通用性和实用性。

简介：Itisurgentandnecessarytointegrateamarinegeographicalinformationsystem(MGIS)withmarineremotesensingdetectionmodules.Onthebasisofthecurrenttechnologyandfeaturesofapplications,anopenthree-layerintegrationframeworkisdesigned.Atthedatalayer,atwo-levelthree-baseintegrationmechanismbasedontheplug-intechnologyisapplied;Atthefunctionlayer,anintegrationmodebasedonAPI,DLL,EXEandCOMisdiscussed;andattheapplicationlayer,asharingmechanismbasedontheclients/serviceisadopted.Asanexample,theremotesensingintegratedapplicationinformationsystemofChina'scoastalzoneandoffshore(MaXplorer1.0)withmultiecologyremotesensingfusionandassimilationmodule,surgedetectionmoduleaswellaseightotherthematicapplicationmodulesisintegrated,andthekeytechnologyofintegrationisdiscussedatdifferentlayersandindifferentmodules.Theresultshowsthatitispossibletorealizetheconformityoftechnologyandresourcesandtoprovidetheincorporatetechnologyplatformformarineinformationoperationalfunctioningafterapplyingtheintegrationframework

简介：Theunderwateracousticimagetransmissionsystembasedonthehigh-speedDSPdeviceTMS320C549hasbeenstudied.WeuseGoertzelalgorithmforsourcedecodingandMFSKformodulation.Turbocodeisusedforchannelcodinganddecoding.Thepurposeistoimplementunderwatervideoimagedatatransmission.

简介：利用Landsat7ETM＋遥感图像反射率和实测水深值之间的相关性，建立了动量BP人工神经网络水深反演模型，并对长江口南港河段水深进行了反演。结果表明：具有较强非线性映射能力的动量BP神经网络模型能较好地反演出长江口南港河段的水深分布情况：由于受长江口水体高含沙量的影响，模型对小于5m的水深值反演精度较高，而对大于10m的水深值反演精度较低。

简介：利用Landsat7ETM+遥感图像反射率和实测水深值之间的相关性,建立了动量BP人工神经网络水深反演模型,并对长江口南港河段水深进行了反演。结果表明:具有较强非线性映射能力的动量BP神经网络模型能较好地反演出长江口南港河段的水深分布情况;由于受长江口水体高含沙量的影响,模型对小于5m的水深值反演精度较高,而对大于10m的水深值反演精度较低。更多还原

简介：Inthispaper,anewbiasestimationmethodisproposedandappliedinaregionalensembleKalmanfilter(EnKF)basedontheWeatherResearchandForecasting(WRF)Model.Themethodisbasedonahomogeneouslinearbiasmodel,andthemodelbiasisestimatedusingstatisticsateachassimilationcycle,whichisdifferentfromthestateaugmentationmethodsproposedinpreviousliteratures.Thenewmethodprovidesagoodestimationforthemodelbiasofsomespecificvariables,suchassealevelpressure(SLP).AseriesofnumericalexperimentswithEnKFareperformedtoexaminethenewmethodunderasevereweathercondition.Resultsshowthepositiveeffectofthemethodontheforecastingofcirculationpatternandmeso-scalesystems,andthereductionofanalysiserrors.ThebackgrounderrorcovariancestructuresofsurfacevariablesandtheeffectsofmodelsystembiasonEnKFarealsostudiedundertheerrorcovariancestructuresandanewconcept‘correlationscale’isintroduced.However,thenewmethodneedsfurtherevaluationwithmorecasesofassimilation.

简介：Generallytheunderwaterbio-robotstakethetailfinaspropulsor,andcombinedwithpectoralfintheycanmanoeuvreagilelyandcontroltheirpositionandmovementatwill.Innature,alotoffishesrealizetosuspenditselfinwatertogoforwardandtomovebackupbythepectoralfinmovingcomplexly.Sothatitissignificanttheoreticallyandvaluableforpracticalapplicationtoinvestigatethepropulsiveprincipleandhydrodynamicperformanceofpectoralfin,andfindthemethodutilizingthepectoralfintomanoeuvretheunderwaterbio-robotagilely.Inthispaper,atwodegreeoffreedom(DoF)motionmodelisestablishedforarigidpectoralfin,andthehydrodynamicperformancesofthepectoralfinarestudiedbyuseofthepectoralfinpropulsiveexperimentalplatformdevelopedbyHarbinEngineeringUniversity,simultaneouslythehydrodynamicperformanceofthepectoralfinisanalyzedwhensomeparameterschange.Then,throughthesecondarydevelopmentofFLUENT(CFDcode)software,thehydrodynamicperformancesofrigidpectoralfininviscousflowsarecalculatedandtheresultsarecomparedwiththelatestexperimentalresults.Theresearchinthispaperwillprovidethetheoreticalreferenceforthedesignofthemanoeuvringsystemimitatingpectoralfin,atthesametimewillbecomethefoundationforthedevelopmentofthesmallunderwaterbio-robot.

简介：Tofulfiltheneedofdevelopmentofoffshoreoilfloatingproductionsystem,theperformanceofturretassemblyinaninboardturretmooringsystemhasbeeninvestigatedinthepaper.Bymeansofsystematicevaluation,theoptimalstructureoftheturretforsingle-pointmooringsystemshasbeendetermined.Throughmodeltestsofaturretmooringsystem,severalgroupsofdatasuchasforces,momentsanddisplacementsunderdifferentenvironmentalconditionshavebeenobtained.Stressesandstrainsoftheturretstructurehavebeencalculatedbymeansofthefiniteelementmethodcorrespondingtothesituationinthemodelexperiment.Thestudyshowsthattheselectedturretstructureandthedesignedturretassemblyaretechnicallyfeasible.

简介：这份报纸为察觉描述一个新框架并且追踪在水下管道，它包括软件系统和硬件系统。它基于单眼用的电荷耦合器件照相机为AUV的视觉系统被设计。首先，从图象俘获卡片的即时数据流动被预先处理，管道特征为航行被提取。区域浸透度被推进在Sobel操作以后移开假边点组。一个适当方法被建议在Hough变换的过程在山峰点附近清除骚乱。第二，管道布局的连续性被考虑改进线抽取的效率。一旦线信息被获得了，参考书地区被Kalman过滤器预言。它在图象表示管道的可能的外观位置。Kalman过滤器被用来在下个框架估计这个位置以便每个框架的管道的信息能预先被知道。在坦克实验在真实眼的视觉数据上获得的结果被显示并且讨论。他们证明建议系统能检测并且追踪在水下管道联机，并且有效、可行。

简介：Takifugu的消化道在早年生活舞台期间磨擦ripes与光被学习显微镜学。在孵化的开始，消化道被一个简单、无差别的直试管代表并且不与外表交流，因为嘴和肛门还不是开的。在在孵化以后的2d，在将成为intestino直肠的阀门的肠和直肠之间的收缩是可见的。在内长的喂阶段期间，蛋黄囊被再吞，消化道变得功能、区分。肝和胰在这时候也变得明显。在外长的喂的发作(在孵化以后的3d)，蛋黄囊resesvesare不完全弄空，建议混合营养的经期。消化道充分区分进buccopharynx，食管，胃，肠和直肠。在在孵化以后的9d，蛋黄囊储备完全被弄空。从5to发生的最显著的事件在孵化以后的17d是epithelia类型，灵魂囊的区别，上皮的房间，内脏卷绕旋转，mucosal褶层增加，和肝和胰的生长的转变。从在孵化以后的18～27d，肠褶层和粘液房间的数字日益增多地增加。从那时起，消化特征的词法变化几乎被完成。在在孵化以后的27d，消化系统的形态学和函数类似于成年人的。

简介：Offshorestructureswillencounterseriousenvironmentalload,soitisimportanttostudythestructuralsystemreliabilityandtoevaluatethestructuralcomponentsafetyrank.Inthispaper,thebracnch-and-boundmethodisadoptedtosearchthemainfailurepath,andtheDitlevsenboundmethodisusedtocalculatethesystemfailureprobability.Thestructureisthenassessedbythefuzzycomprehensiveassessmentmethod,whichevaluatesthestructuralcomponentsafetyrank.Theultimateequationofthetu-bularcross-sectionisanalyzedonthebasisofultimatestregnthanalysis.Theinfluenceofeffectcoefficientsonthestructuralsystemfailureprobabilityisinvestigated,andbasicresultsareobtained.Ageneralprogramforspatialframestructuresbymeansoftheabovemethodisdeveloped,andverifiedbythenumericalexamples.

简介：Inthispaper,anewdefinitionofstructuresystemredundancyisproposedinviewofthevariousmeasuresforstructureredundancy.Byintroducingthetermsofstructuresystemfailureatthemechanismlevelandequivalentreliabilityindex,thesafetyforexistingoffshoreplatformscanbeevaluatedbythesemi-probabilisticmethodpresentedinthispaper.Somenumericalexamplesaregivenandsatisfactoryresultshavebeenobtained.

简介：Mobileoffshoredouble-causewaypiersystem,atypeofseashoreunloadingequipment,consistsoftwogroupsofmultipleconnectedsemi-submersiblemodules.Thisstructurehaswideapplicationbecausemostofthemiddleorminitypeofvesselsandshipscanbemooredtoit.Basedontheanalysisofcomputationalmethodsofmulti-bodymotionresponse,ahydrodynamicmodelissetupandthethree-dimensionalpotentialtheoryinfinitedepthisadoptedtocalculatethethree-dimensionalmotionresponseofthissystem.ThedoubleP-Mspectrumisusedtoanalyzethemotionresponseinirregularwaves.Differentwavedirectionsarespeciallytakenintoconsideration,duetotheirvariouseffectstothemotionresponse.Furthermore,thecalculatedresultiscomparedwiththatoftheexperiment,anditisprovedthatsway,heave,pitchandyawmotionaregreatlyconstrainedbymooringsystem.Thecomparisonalsoindicatesthatthemodelcanforecastthemotionperformanceofthetarget,andthatthecalculatedresultcanalsobeusedasreferenceinconnectorandmooringsystemdesign.

简介：Freakwaveisthecommonwavewhichhassignificantwaveheightandirregularwaveshape,anditiseasytodamageoffshorestructureextremely.TheFPSOs(FloatingProductionStorageandOffloading)sufferfromtheenvironmentloads,includingthefreakwave.Thefreakwavesweregeneratedbasedontheimprovedphasemodulationmodel,andthecouplingmodelofFPSO-SPM(SinglePointMooring)wasestablishedbyconsideringinternal-turretFPSOanditsmooringsystem.ThedynamicresponsecharacteristicsofbothFPSOandSPMaffectedbythefreakwavewereanalyzedinthetimedomain.Accordingtotheresults,thefreakwavesgeneratedbyoriginalphasemodulationmodelmainlyaffectthe2nd-orderwaveloads.However,thefreakwaveswhicharegeneratedbyrandomfrequenciesphasemodulationmodelaffectboth1st-orderand2nd-orderwaveloadsonFPSO.Whatismore,comparedwiththeirregularwaves,thedynamicresponsesofmooringsystemarelargerinthefreakwaves,butitsamplitudelagsbehindthepeakofthefreakwave.

简介：微粒样品在一个洪水时期期间从Changjiang河系是镇定的，在1997年5月，并且与粒子联系的停靠港，稳定同位素和类脂化合物被检验。结果显示出减少(0。84%～1.88%)到河口的从上面的活动范围的器官的碳内容。器官的碳在-24的范围的微粒的δ~(13)C价值。9X10~(-3)到-26。6x10~(接近了大陆人C_3vegetation的同位素的签名的-3),。全部的微粒n链烷集中从1.4～10变化了。1μg/dm~3，或from23.7到全部的浮游物的107μg/g。丰满的酸在所有样品是在场的，从1.4to5.4μg/dm~3，与浸透并且在碳数字的不饱和的直链、分叉的混合物从C_(12)到C_(30)。δ~(13)C和到氮内容的碳内容的比率在粒子之中显示陆上的输入(土壤有机物)的优势。简历标记途径被用来在微粒样品识别源自陆地、本土的部分的相对部分。丰满的酸的分发在大多数粒子样品作为triking建议phytoplanktonic和微生物引起的信号。陆上的链烷被用来沿着主流估计陆上的输入的贡献。

简介：Theinternalturretmooringsystemforoilproductionstoragevesselsisadevelopingtypeofoffshorefloatingproductionsystemsuitablefordeepwaterandharshenvironmentalapplication.Inthispaper,someachievementsinourresearchworkarepresented.Thedescriptionincludes:dynamicanalysisofmooringsystem,researchonperformanceofturretassembly,influenceofvesseldimensionsandhullformsonmooringperformance,modeltestsundercombinedactionofenvironmentalforcesinbasin,andhullstructuralstrengthanalysis.

简介：Theoperationalclimateforecastsystem(CFS)oftheUSNationalCentersforEnvironmentalPredictionprovidesclimatepredictionsovertheworld,andCFSproductsarebecominganimportantsourceofinformationforregionalclimatepredictionsinmanyAsiancountrieswheremonsoonclimatedominates.Recentstudieshaveshownthat,onmonthly-to-seasonaltime-scales,theCFSishighlyskillfulinsimulatingandpredictingthevariabilityoftheAsianmonsoon.Thehigher-frequencyvariabilityoftheAsiansummermonsoonintheCFSisanalyzed,usingoutputfromaversionwithaspectraltriangulartruncationof126wavesinhorizontaland64sigmalayersinvertical,focusingonsynoptic,quasi-biweekly,andintraseasonaltime-scales.TheonsetprocessesofdifferentregionalmonsooncomponentswereinvestigatedwithinAsia.AlthoughtheCFSgenerallyoverestimatesvariabilityofmonsoononthesetime-scales,itsuccessfullycapturesmanymajorfeaturesofthevariancepatterns,especiallyforthesynoptictime-scale.TheCFSalsocapturesthetimingofsummermonsoononsetsoverIndiaandtheIndo-ChinaPeninsula.However,itencountersdifficultiesinsimulatingtheonsetoftheSouthChinaSeamonsoon.ThesuccessandfailureoftheCFSinsimulatingtheonsetofmonsoonprecipitationcanalsobeseenfromtheassociatedfeaturesofsimulatedatmosphericcirculationprocesses.Overall,theCFSiscapableofsimulatingthesynoptic-to-intraseasonalvariabilityoftheAsiansummermonsoonwithskills.Asforseasonal-to-interannualtime-scalesshownpreviously,themodelisexpectedtopossessapotentialforskillfulpredictionsofthehigh-frequencyvariabilityoftheAsianmonsoon.