简介:近年来,一些学者对互联网的拓扑结构进行了深入的研究,发现在互联网拓扑中存在幂律(Power-Law),其相关系数最高可达到99%.本文在Internet的每个子图上引进连接率的概念以刻划该子图中结点相互连接的程度,然后对Internet中的结点按其连接边数的多少由多到少进行排序,通过逼近实验和理论推导两个方面的工作,发现在Internet前r个结点的诱导子图上的连接率作为子图上结点数r的函数满足幂律,其相关系数超过99.3%.这一结果是目前在In-ternet中所发现的吻合得相当好的幂律,期望它可推动Internet拓扑结构的整体性质的深入研究.
简介:Objectivesofthistaskaretoconductresearchonseismichazards,andtoproviderelevantinputontheexpectedlevelsofthesehazardstoothertasks.Othertasksrequiringthisinputincludethosedealingwithinventory,fragilitycurves,rehabilitationstrategiesanddemonstrationprojects.Thecorrespondinginputisprovidedinvariousformatsdependingontheintendeduse:aspeakgroundmotionparametersand/orresponsespectralvaluesforagivenmagnitude,epicentraldistanceandsiteconditions;orastimehistoriesforscenarioearthquakesthatareselectedbasedonthedisaggregatedseismichazardmappedbytheU.S.GeologicalSurveyandareincorporatedinbuildingcodes.Theusercommunityforthisresearchisbothacademicresearchersandpracticingengineerswhomayusetheseismicinputgeneratedbythesynthesistechniquesthataredevelopedunderthistaskforavarietyofapplications.Theseincludegroundmotionsforscenarioearthquakes,fordevelopingfragilitycurvesandinspecifyinggroundmotioninputforcriticalfacilities(suchashospitals)locatedintheeasternU.S.
简介:Asarecent-boomingfield,China’sculturalandcreativeindustryhasacertaingapcomparedwithdevelopedcountries,buttherealsoexistsapotentialforitsmarketprospect,togetherwiththehelpofChinesegovernmentpolicies.What’smore,thefast-growinginternethasstillprovidedtheindustrywithmorepossibilitiesoffurtherdevelopment.AnalysissuggeststhattheinternetinevitablyoptimizesChina’sculturalandcreativeindustrybyre-integrationofmassiveresources,promotingitssustainableinnovation.Thusthenewindustrialchainiscreated,andmoreprofitswouldfloodintothecompaniesinthisfieldinthemeantime.Inotherwords,theecosystemofChina’sculturalandcreativeindustryisestablishedinthisway,whichwouldenjoyaprosperousprospectforsure.
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简介:BasedonQoS(qualityofservice)parameters:timedelay,jitter,bandwidthandpackageloss.AstimedelayintheInternetisvariable,itishardtocompensateitbytraditionalmethods.Eventsynchronizationcommunicationdrivenmethodisproposedtoovercomethenegativeeffectsinducedbytimedelay.Thismethodisanon-timebasedmethodanditcangetridoftheeffectsoftimeinthecontrolloopoftelerobotics.Stability,transparencyandsynchronizationcanbemaintainedinitbyevent-drivenmethod.Multimodalenhancedteleroboticsisputforwardwithitsfeedbackincludingforce,video,audioandtemperatureetc.Theuseofmultimodalfeedbackimprovestheefficiencyandsafetyofthewholesystem.Synchronizationinmultimodalfeedbackishardtoensureandevent-drivenmethodisalsogoodforit.ExperimentsonanInternet-basedshaft-holeassemblagesystemshowgoodresultsbyusingeventsynchronizationcommunicationdrivenmethodandUDPprotocol.