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:当前,信息技术处于爆发性的增长状态中,并渗透到各行各业和人们的日常生活中。同时,随着移动设备的普及,将空间信息技术与传输通信进行电子集成应用将是未来信息技术发展的必然走向。本文简要分析了空间信息技术与传输通信电子集成的应用价值,并对其集成网络系统模式进行了探讨和应用分析,希望能够给有关的工作人员提供一些可资借鉴的地方。
简介:网络传输可以分为四种形态:“一对一”,“多对一”,“一对多”和“多对多”。“一对一”是问题分解的终极,而“多对多”则是效率所追求的终极。由四种形态之间转变展开讨论,为了提高效率,网络传输应该转向“多对多”。群对群是“多对多”的另一种传输方式,或者说,是强调分群的“多对多”传输。