简介：Inordertoanalyzethespatialmaneuverabilityoftheremotelyoperatedunderwatervehicle(ROV),the6-DOFmotionmathematicmodeloftheROVwasfounded.HydrodynamicswereanalyzedbyusingtheTaylorseries.ThethrustersontheROVwerediscussed.Thispaperconsidersthreecasesofmotionsimulation:verticalmotion,rotationalmotionandZ-shapemotion.Aseriesofsimulationexperimentsshowedthatthe6-DOFmotionmathematicmodelwascorrectandreliable,andalsofitwiththescenesimulation.

简介：对自主式潜器空间运动进行精确建模和仿真对研究其操纵和控制特性有重要意义，本文以开发的“MAUV-Ⅱ”微小型潜器为对象，基于动量定理和动量矩定理建市了潜器空间运动的非线性数学模型，将潜器受力分解为各个模块并表达为矩阵形式。在运动非线性数学模型的基础上，结合虚拟现实技术建立了运动仿真系统，针对所研究潜器的特点，采用S面控制方法对此“MAUV-Ⅱ”水下运动的艏向控制和深度控制进行了仿真研究，同时进行了基于目标规划的长距离航行仿真试验。仿真结果反映了潜器具有较好的空间操纵性能，也验证了控制软件的可行性和可靠性。

简介：本文基于五阶Stokes规则波理论，提出了一种快速求解深海极限波浪运动特性的数学模型。研究中，按照卜跨零点和下跨零点的方法由计算或实测的极限波浪波面时间历程确定包含极限波峰或波谷的相邻两个周期的平均值为五阶Stokes规则波的波浪周期，然后根据极限波峰或波谷值反推确定波浪入射波幅。通过与已有的数值结果和实验数据对比，验证了本文所建立的数值模型可以快速准确的计算出极限波浪下的速度场，相比其他模型，更适合于工程应用。

简介：武术是中华民族的瑰宝,千百年来一直是中国人民赖以生存的健身术、自卫术和养生术.中国人民在长期的武术锻炼中练就了强健的体魄,学会了防身的本领,使生命的质量得到了提高.因此,在举国上下全民健身的今天,重新认识和研究武术运动在全民健身中的积极作用,有着重要的意义.

简介：本文研究水深与吃水的比值小于3的浅水域对船舶操纵运动的影响.建立数学模型仿真预报船舶在不同舵角不同水深与吃水比下的操纵运动轨迹,分析了船舶在浅水中的操纵运动性能,避免产生事故,为各型船舶的操纵性研究提供借鉴.

简介：Thecriticaltechnicalproblemofunderwaterbottomobjectdetectionisfoundingastablefeaturespaceforechosignalsclassification.Thepastliteraturesmorefocusonthecharacteristicsofobjectechoesinfeaturespaceandreverberationisonlytreatedasinterference.Inthispaper,reverberationisconsideredasakindofsignalwithsteadycharacteristic,andtheclusteringofreverberationinfrequencydiscretewavelettransform(FDWT)featurespaceisstudied.Inordertoextracttheidentifyinginformationofechosignals,featurecompressionandclusteranalysisareadoptedinthispaper,andthecriterionofseparabilitybetweenobjectechoesandreverberationisgiven.TheexperimentaldataprocessingresultsshowthatreverberationhassteadypatterninFDWTfeaturespacewhichdiffersfromthatofobjectechoes.Itisproventhatthereisseparabilitybetweenreverberationandobjectechoes.

简介：Foralargefloatingvesselinwaves,radiationdampingisnotanaccuratepredictionofthedegreeofrollunlikeotherdegreesoffreedommotion.Therefore,togettheknowledgeofrollmotionperformanceofdeepwaterpipelaycranevesselsandtokeepthevesselworkingsafety,thepaperpresentstherelationshipbetweenaseriesofdimensionlessrolldampingcoefficientsandtherollresponseamplitudeoperator(RAO).Byusingtwokindsofempiricaldata,therolldampingisestimatedinthecalculationflow.Aftergettingtherolldampingcoefficientfromthemodeltest,apredictionofrollmotioninregularwavesisevaluated.Accordingtothewaveconditionintheworkingregion,shorttermstatisticsofrollmotionarepresentedunderdifferentwaveparameters.Moreover,therelationshipbetweenthemaximalrollresponseleveltopeakspectralwaveperiodandtherolldampingcoefficientisinvestigated.Resultsmayprovidesomereferencetodesignandimprovethiskindofvessel.

简介：广东作为我国近代民主革命的策源地,素开风气之先.近代以来,广东成为最早遭受西方列强侵略蹂躏的前沿阵地,无数妇女同胞惨遭蹂躏和屠杀,广东人民包括广大妇女同胞最早发起了反帝反封建的艰苦卓绝的民主革命运动,为争取民族解放以及妇女自身解放与权益,她们前赴后继,英勇抗争,卓有成效.近代广东妇女运动风起云涌,有效促进了我国妇女运动的蓬勃发展和壮大,培养和造就了一大批妇女运动的人才和骨干,为全国妇女解放运动和北伐的发展奠定了坚实的基础力量.

简介：目标在成像过程中发生的几何变形在更多情形时用仿射变换来刻画,光照变化也是影响目标识别的重要因素.在一种典型的简化的光照变化约束下,将光照的灰度线性变化融入目标的几何变形,基于子空间流形理论,提出了仿射光照不变形状空间概念,分析了仿射光照不变形状空间的非线性几何结构,给出了仿射光照不变形状识别算法,模拟图像和真实图像序列实验验证了算法的有效性,该几何框架为研究几何和光照变化下的目标识别提供了新的途径.

简介：足球比赛情况错综复杂、变化莫测,强与弱是相对的.在一定的条件下,优势与劣势可以相互转化.因此,教练员在注意加强运动员技术、战术和身体素质训练的同时,还要注意加强运动员良好心理素质的训练与培养.

简介：体育运动与爱国主义精神刍议于洪波（大连海事大学）随着社会经济的发展和人民生活水平的提高，体育运动在国家政治和民众生活中的地位逐步加强，体育运动水平作为国家和地区实力地位的象征其意义更加显著，使大型运动会越来越受到全社会的关注和响应，其规模不断扩大，成...

简介：应用GPS载波相位信号确定运动体姿态，针对二维两天线系统情况，设计了姿态测量系统的硬件结构及算法流程框图，文章介绍了GPS姿态测量的关键技术：GPS姿态观测方程、整周模糊度的解算、误差的消除。从系统设计角度证明了技术的可行性。

简介：Toprovideasimulationsystemplatformfordesigninganddebuggingasmallautonomousunderwatervehicle’s(AUV)motioncontroller,asix-degreeoffreedom(6-DOF)dynamicmodelforAUVcontrolledbythrusterandfinswithappendagesisexamined.Basedonthedynamicmodel,asimulationsystemfortheAUV’smotionisestablished.ThedifferentkindsoftypicalmotionsaresimulatedtoanalyzethemotionperformanceandthemaneuverabilityoftheAUV.InordertoevaluatetheinfluencesofappendagesonthemotionperformanceoftheAUV,simulationsoftheAUVwithandwithoutappendagesareperformedandcompared.TheresultsdemonstratetheAUVhasgoodmaneuverabilitywithandwithoutappendages.

简介：Inordertominimizetheharmcausedbytheinstabilityofaplaningcraft,amotionpredictionmodelisessential.ThispaperanalyzedthefeasibilityofusinganMGM(1,N)modelingreysystemtheorytopredictplaningcraftmotionandcarriedoutthenumericalsimulationexperiment.Accordingtothecharacteristicsofplaningcraftmotion,arecurrenceformulawasproposedoftheparametermatrixofanMGM(1,N)model.Usingthisformula,datacanbeupdatedinreal-timewithoutincreasingcomputationalcomplexitysignificantly.TheresultsofnumericalsimulationshowthatusinganMGM(1,N)modeltopredictplaningmotionisfeasibleandusefulforprediction.Sothemethodproposedinthisstudycanreflecttheplaningcraftmotionmechanismsuccessfully,andhasrationalandeffectivefunctionsofforecastingandanalyzingtrends.

简介：Stronghydrodynamicinteractionsduringtheside-by-sideoffloadingoperationbetweenfloatingliquefiednaturalgas(FLNG)andliquefiednaturalgascarrier(LNGC)caninducehighrisksofcollision.Theweathervaneeffectofasingle-pointmooringsystemnormallyresultsinthesatisfactoryhydrodynamicperformanceoftheside-by-sideconfigurationinheadseas.Nevertheless,thechangesinwavedirectionsinrealseaconditionscansignificantlyinfluencetherelativemotions.Thisarticlestudiestherelativemotionsoftheside-by-sidesystembyusingthetheoreticalanalysismethodandthenumericalcalculationmethod.Basedonthethree-dimensionalpotentialtheorymodifiedbyartificialdamping-lidmethod,thefrequency-domainhydrodynamiccoefficientscanbeimprovedtocalculatetheretardationfunctionsforthemulti-bodyproblem.Anin-housecodeisthendevelopedtoperformthetime-domainsimulationoftwovessels,throughwhichtherelativemotionsaresubsequentlyobtained.Arangeofobliquewavesarechosenfortheextensivecalculationofrelativemotionsbetweenthetwovessels,whicharefurtheranalyzedintermsofthephaseshiftofmotionresponsesinducedbyspecificresonantwavepatterns.Investigationresultsshowthatwavedirectionshaveasignificantinfluenceontherelativesway,roll,andyawmotions.Underthecircumstancethattheabsolutephaseshiftbetweentherollmotionsoftwovesselsapproaches180°,strongerrelativemotionsareinducedwhenLNGCisontheweatherside.Moreover,thegapwaterresonancesathighfrequenciestendtocausethedangerousopposedoscillationoftwovesselsintheswayandyawmodes,whereasFLNGreducesthegapwaterresonancesandrelativemotionswhenlocatedontheweatherside.

简介：Ananalyticalstudywaspresentedonactivecontrolofsoundtransmissionintoavibro-acousticenclosurecomprisingtwoflexibleplates.Twotypesofactuatorswereused,i.e.acousticactuatoranddistributedleadzirconatetitanatepiezoelectric(PZT)actuatorinsteadofpointforceactuator.Usingthemodalacoustictransferimpedance-mobilitymatrices,theexcitationandinteractioninthecoupledsoundtransmissionsystemcanbedescribedwithclearphysicalsignificance.Withthecontrolsystemdesignedtogloballyreducethesoundfield,differentcontrolsystemconfigurationswereconsidered,includingthestructuralactuatorontheincidentplate,actuatoronthereceivingplate,acousticactuatoronthecavity,andtheircombinations.Theeffectivenessandperformanceofthecontrolstrategycorrespondingtoeachsystemconfigurationwerecomparedanddiscussed.Theroleandcontrolmechanismofeachtypeofactuatorwereofparticularinterest.Itwasshownthattheincidentplateactuatoriseffectiveincontrollingthecavity-dominatedmodesandthestructuralmodesdominatedbytheincidentplateandreceivingplate.Twomaincontrolmechanismsareinvolvedinthiscontrolconfiguration,i.e.,modalsuppressingandmodalrearrangement.Forcontrolsystemconfigurationwithonlyacousticactuatorintheenclosure,themechanisminvolvedinthisarrangementispurelymodalsuppression.Desirableplacementsofstructuralactuatorsintermsoftotalpotentialenergyreductionwerealsodiscussed.

简介：以集装箱班轮航线为基础,构建以港口为节点、港口间的运力为边权重的有向加权海运网络,并从中抽取出与广州港、深圳港以及香港港有联系的港口节点和边.在此基础上,分别从出口货流和进口货流两个角度对广州港、深圳港以及香港港的集装箱货流在全球17个海运区域的空间分布情况进行对比,并就出口货流和进口货流在上述三个港口之间的集聚程度进行了分析.结果表明:(1)无论是在进口货流还是出口货流方面,与香港港建立联系的海运区域数量都是最多的,香港港的港口通达性最好;(2)深圳港的货流总量高于香港港和广州港;(3)进口货流主要集中在香港港,出口货流主要集中在深圳港;(4)东非、南部非洲、南美东岸和西非区域的进口货流呈现高度集聚分布的特点.

简介：如何减小波浪对舰船工作所造成的影响已经成为舰船发展中极具挑战性的问题.本文以荷兰某公司设计的三自由度波浪补偿控制平台为研究对象,在分析该结构补偿装置平台的空间结构和空间姿态的位置解算的基础上,运用ADAMS软件完成该平台在横摇、纵摇及横荡三种运动复合运动下的运动学正、逆解仿真与分析和动力学仿真与分析,为波浪补偿装置平台的设计提供可靠的的理论数据基础.