简介:ThispapershowsanumberofproblemsinpureandappliedmathematicsthataresolvedbyconstructingtransportationnetworksMoreover,italsoshowsthatallthesolutionsarecharacterizedbyforbiddenconfiguratlozzwhicharenotminors.However,allthecharacterisationsaremuchrelatedtothegraphicmethodwhichwasfoundbyChineseforsolvingakindofthetransportationprobleminthefifties.
简介:Thispaperanalysestheoreticallytheeffectoftransportationandhousingsubsidiesonurbansprawl,modalchoicedecisionsandurbanspatialstructureusingaspatialgeneralequilibriummodelinamonocentriccitywithtwotransportmodes.Ouranalysisshowsthatpublictransitsubsidyleadstourbanshrink,whilstsubsidizingautomobileandhousingmakethecitysprawl.Wealsofindtheeffectsoftheotherfactorsonurbansprawl,suchashouseholdsincomeanddemand,rurallandrent,theincometaxrate,thetotalfixedcostofpublictransitandautomobileandthetravellingmarginalcostofpublictransitandautomobile.Furthermore,thispaperalsostudieshowtomaximizetheurban-area-widespatialequilibriumutilitylevel.
简介:Theobjectiveofthisresearchistodeterminetheeffectearthquakeshaveontheperformanceoftransportationnetworksystems.Todothis,bridgefragilitycurves,expressedasafunctionofpeakgroundacceleration(PGA)andpeakgroundvelocity(PGV),weredeveloped.Networkdamagewasevaluatedunderthe1994Northridgeearthquakeandscenarioearthquakes.Aprobabilisticmodelwasdevelopedtodeterminetheeffectofrepairofbridgedamageontheimprovementofthenetworkperformanceasdayspassedaftertheevent.Asanexample,thesystemperformancedegradationmeasuredintermsofanindex,"DriversDelay,"iscalculatedfortheLosAngelesareatransportationsystem,andlossesduetoDriversDelaywithandwithoutretrofitwereestimated.
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简介:煤是一个基本资源,它的使用保证国民经济和人的社会的发展。因此,煤交通是瓷器全面交通系统的重要部分。在这个系统,港口是重要运输节点。这研究在中国考虑了沿海的港口并且从1973~2013分析了煤交通的进化。我们集中了于装载并且卸掉的煤的空间模式,并且总结了这些进程的主要特征和开发。然后,我们用数学模型和指示物在这些数量检验了搬运的煤和地区性的变化的体积。最后,我们分析了专业化功能和涉及煤交通揭示他们的空间关系和时间的进化的港口的空间区别。我们发现煤交通的空间模式从南方输入和北方输出改变了到所有输入和北方输出。然而,突出的港口使用了因为卸掉的煤仍然长江向南在区域被集中。装载的煤被专注于Bohai的西岸海湾。另外,在Bohai海湾附近的一些港口例如Dandong,Dalian,Yantai,和Qingdao,从装载港口到卸掉港口的传统的煤变化了。这研究进一步开发了运输地理的理论,并且改进了我们瓷器煤交通系统的理解。
简介:Afterthepyramids,obelisksmustbethemosticonicsymbolofAncientEgypt,butvisuallylittleisknownaboutthemeansbywhichtheirtransportationwaseffected,otherthanaNewKingdomscenefromDeirel-Baharioftheconveyanceofobelisksbywater,aboardalighter.1Theonlyothericonographicsource,untilrecently,whichapproachedadepictionofsuchanactivity,wasanOldKingdomscenedepictingtheconveyanceofgranitepalmettecolumnsbybargetothepyramidcomplexofUnas.2NeitherthishulltypenorthelighterappearinGardiner’sregisterofship/boatdeterminatives,3norinReisner’stypologyseries.4IhavecategorizedtheUnasvesselasanETH10vessel.5
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简介:Thetransportationindustryisanessentialsectorforcarbonemissionsmitigation.ThispaperfirstlyusedtheLMDI(LogarithmicMeanDivisiaIndex)decompositionmethodtoestablishfactorsdecompositionmodelonChina’stransportationcarbonemission.Then,aquantitativeanalysiswasperformedtostudythefactorsinfluencingChina’stransportationcarbonemissionsfrom1991to2008,whichareidentifiedastransportationenergyefficiency,transportationstructureandtransportationdevelopment.Theresultsshowedthat:(1)Theimpactoftransportationdevelopmentontransportationcarbonemissionsshowedpullingfunction.Itscontributionvaluetocarbonemissionsremainedathighgrowthsince1991andshowedanexponentialgrowthtrend.(2)Theimpactoftransportationstructureontransportationcarbonemissionsshowedpromotingfunctioningeneral,butitsroleinpromotingcarbonemissionsdecreasedyearbyyear.Andwiththecontinuousoptimizationoftransportationstructure,thepromotingeffectdecreasedgraduallyandshowedtheinversed"U"trend.(3)Theimpactoftransportationenergyefficiencyontransportationcarbonemissionsshowedafunctionofinhibitionbeforepulling.Inordertopredictthepotentialofcarbonemissionreduction,threescenarioswereset.Analysisofthescenariosshowedthatifgreaterintensityemissionreductionmeasuresaretaken,thecarbonemissionswillreduceby31.01milliontonsby2015andby48.81milliontonsby2020.
简介:Thestudyofairemissioninmaritimetransportationisnew,andtherecognitionofitsimportancehasbeenrisingintherecentdecade.TheemissionsofCO2,SO2,NO2andparticulatemattersfrommaritimetransportationhavecontributedtoclimatechangeandenvironmentaldegradation.Scientifically,analystsstillhavecontroversiesregardinghowtocalculatetheemissionsandhowtochoosethebaselineandmethodologies.Threemethodsaregenerallyused,namelythe'bottomup'approach,the'topdown'approachandtheSTEEM,whichproduceverydifferentresults,leadingtovariouspaperswithgreatuncertainties.This,inturn,resultsingreatdifficultiestopolicymakerswhoattempttoregulatetheemissions.Arecenttechnique,theSTEEM,isintendedtocombinetheformertwomethodstoreducetheirdrawbacks.However,theregulationsbasedonitsresultsmayincreasethecostsofshippingcompaniesandcausethecompetitivenessoftheportstatesandcoastalstates.Quiteafewpapershavefocusedonthisareaandprovidedanotherfreshperspectivefortheairemissiontobeincorporatedinmaritimetransportationregulations;thesefactsdeservemoreattention.Thispaperistoreviewtheliteratureonthedebatesoverairemissioncalculation,withparticularattentiongiventotheSTEEMandtherefinedestimationmethods.Italsoreviewsrelatedliteratureontheeconomicanalysisofmaritimetransportationemissionregulations,andprovidesaninsightintosuchanalysis.Attheendofthispaper,basedonareviewandanalysisofpreviousliterature,weconcludewiththepolicyindicationsinthefutureandworkthatshouldbedone.AstherelatedregulationsinmaritimetransportationemissionsarestillattheirbeginningstageinChina,thispaperprovidesspecificsuggestionsonhowChinashouldregulateemissionsinthemaritimetransportationsector.