简介:文章在Markov跳变系统描述的固定资产投入产出模型基础上,考虑外界的不确定性,引入随机变量,建立了基于离散时间随机Markov跳变系统的固定资产投入产出动态变化模型.接着,把固定资产投入看作博弈的一方,外界随机干扰看作博弈的另一方,在两者之间设计一个随机零和博弈,进而运用鞍点均衡理论设计出求解固定资产投入产出问题的最优策略,并给出最优解的显式形式.
简介:在中海发展与中石油合资建立液化天然气(LNG)公司的背景下,18日,中海集团及旗下3家企业将持有的中海集团液化天然气投资有限公司共100%的股权在上海联合产权交易所联合挂牌,总价逾1亿元。中海发展或早已成为内定的接盘者。17日,中国海运(集团)总公司及其下属上海海运(集团)公司、大连海运(集团)公司,广州海运(集团)有限公司分别将所持有的中海集团液化天然气投资有限公司(下称中海LNG公司)35%、25%、15%、25%的股份联合挂牌。中海发展董事会认为,LNG运输业务发展空间广阔,收益稳定,且与油品运输业务相近,在造船技术、船舶管理、船员调配等方面具有通融性,LNG船运公司不仅符合公司以能源运输为主业的发展战略,也使公司获得新的业务增长点,符合公司利益。
简介:Foralargefloatingvesselinwaves,radiationdampingisnotanaccuratepredictionofthedegreeofrollunlikeotherdegreesoffreedommotion.Therefore,togettheknowledgeofrollmotionperformanceofdeepwaterpipelaycranevesselsandtokeepthevesselworkingsafety,thepaperpresentstherelationshipbetweenaseriesofdimensionlessrolldampingcoefficientsandtherollresponseamplitudeoperator(RAO).Byusingtwokindsofempiricaldata,therolldampingisestimatedinthecalculationflow.Aftergettingtherolldampingcoefficientfromthemodeltest,apredictionofrollmotioninregularwavesisevaluated.Accordingtothewaveconditionintheworkingregion,shorttermstatisticsofrollmotionarepresentedunderdifferentwaveparameters.Moreover,therelationshipbetweenthemaximalrollresponseleveltopeakspectralwaveperiodandtherolldampingcoefficientisinvestigated.Resultsmayprovidesomereferencetodesignandimprovethiskindofvessel.
简介:Themostcriticalissueinthesteelcatenaryriserdesignistoevaluatethefatiguedamageinthetouchdownzoneaccurately.Appropriatemodelingoftheriser-soilresistanceinthetouchdownzonecanleadtosignificantcostreductionbyoptimizingdesign.Thispaperpresentsaplasticitymodelthatcanbeappliedtonumericallysimulateriser-soilinteractionandevaluatedynamicresponsesandthefatiguedamageofasteelcatenaryriserinthetouchdownzone.Utilizingthemodel,numerousriser-soilelementsareattachedtothesteelcatenaryriserfiniteelements,inwhicheachsimulateslocalfoundationrestraintalongtherisertouchdownzone.Theriser-soilinteractionplasticitymodelaccountsforthebehaviorwithinanallowablecombinedloadingsurface.Themodelwillberepresentedinthispaper,allowingsimplenumericalimplementation.Moreimportantly,itcanbeincorporatedwithinthestructuralanalysisofasteelcatenaryriserwiththefiniteelementmethod.Theapplicabilityofthemodelisinterpretedtheoreticallyandtheresultsareshownthroughapplicationtoanoffshore8.625″steelcatenaryriserexample.Thefatigueanalysisresultsofthelinerelasticriser-soilmodelarealsoshown.Accordingtothecomparisonresultsofthetwomodels,thefatiguelifeanalysisresultsoftheplasticityframeworkarereasonableandthehorizontaleffectsoftheriser-soilinteractioncanbeincluded.