简介:Inordertoachieveawheelchairliftfunction,thispaperdesignsatri-scissorsmechanism.Throughtheso-calledH-typetransmissionandL-typeswingrod,thethreescissorsmechanismsliftinthesameratewithonlyonelinermotorwhileensuringthestabilityofthelift.FiniteelementanalysisinANSYSisperformedtoverifythematerialstrength.ThecontrolsystemwithSunplusSCMachievesthevoicecontrolofwheelchairwalkingandlifting.
简介:Topologicalnamingmechanisminfeature_basedmodelingJunjunWu,TongyangWang,XinfangZhangandJizhouComputerAidedDesignCenter,HuaZhon...
简介:Inthispaperanewsignaturescheme,calledPolicy-EndorsingAttribute-BasedSignature,isdevelopedtocorrespondwiththeexistingCiphertext-PolicyAttribute-BasedEncryption.Thissignatureprovidesapolicy-and-endorsementmechanism.Inthismechanismasingleuser,whoseattributessatisfythepredicate,endorsesthemessage.Thissignatureallowsthesignertoannouncehisendorsementusinganaccesspolicywithouthavingtorevealtheidentityofthesigner.Thesecurityofthissignature,selflessanonymityandexistentialunforgeability,isbasedontheStrongDiffie-HellmanassumptionandtheDecisionLinearassumptioninbilinearmapgroups.
简介:两倍缓冲是有效机制隐藏在在薄片上和离开薄片记忆之间的数据转移的潜伏。在dataflow建筑学,因为dataflow加速器的重复充满并且排干,然而,交换二在许多瓦减少的执行期间缓冲性能。在这个工作,我们为dataflow建筑学建议连续双的缓冲机制。没有停止通过在dataflow建筑学优化控制逻辑处理元素的执行,建议不停的机制把瓦分到处理元素数组。而且,我们建议一个工作流节目与连续双的缓冲机制合作。在控制逻辑上并且在工作流节目上的优化以后,充满并且排干数组需要越过属于一样的dataflow图的所有瓦的执行被做仅仅一次。试验性的结果证明没有优化,为dataflow建筑学的建议双缓冲机制在那上完成16.2%平均效率改进。
简介:Inthispaper,aquantitativeQoSmanagementimplementmechanisminIP-DiffServispresented.Theapproachhasthreemerits:(1)itoptimizesboththerouteselectedforserviceclassbytrafficengineeringinnetworklayerandtheserviceclassselectedfortheuserservicesbynetworkplaninservicelayer,(2)itensuresquantitativeQoSfortheuserserviceinDiffServ,(3)itachieveshighresourceutilization,andachievesbetterperformancewithlesscostfortheuserserviceandselectedroute.Simulationhasverifiedthesemerits.
简介:Motioncontrolcanbeconsideredasthesynergisticcollaborationofmechanicalandelectricalengineering,computerscienceandinformationtechnologytoapplyacontrolledforcetoachieveusefulmotioninfluidorsoiledelectromechanicalsystems.Withthedevelopmentofcomputer,electronics,andautomaticcontroltheory,motioncontrolcomestoanewstage.Greatapplicationsarebasedonthecharacteristics,stemmingfromadvantagesofelectronicsandmoderncontroltechnologyachievements,havingaverygoodloadmatchingproperty.Currently,microprocessor-basedcontrollersareinvariablyusedinmostapplicationsofdriveelectronics.Theobjectofthisworkistodesignapositioncontrolmechanismsystem,whichcanbeusedintestsectionoflowspeedwindtunnel.Systemloadspecificationsandperformancerequirementsaregiven.Acomprehensivestudyofmathematicalmodelingofthemechanismcomponentsisgiven.Procedureforselectionofvariouscomponentswithoptimumparametersisdiscussed.Afterselectionandcalculationofsystemparameterstomeettheperformancerequirements,aPIDcontrolmethodisadopted.
简介:IEEE802.15.4protocolisproposedtomeetthelowlatencyandenergyconsumptionneedsinlow-ratewirelessapplications,however,fewanalyticalmodelsaretractableenoughforcomprehensiveevaluationoftheprotocol.ToevaluatetheIEEE802.15.4slottedCSMA/CAchannelaccessmechanisminthispaper,weproposeapracticalandaccuratediscreteMarkovchainmodel,whichcandynamicallyrepresentdifferentnetworkloads.Bycomputingthesteady-statedistributionprobabilityoftheMarkovchain,weobtainanevaluationformulaforthroughput,energyconsumption,andaccesslatency.Thenwefurtheranalyzetheparametersthatinfluenceperformanceincludingpacketarrivalrate,initialbackoffexponentandmaximumbackoffnumber.Finally,NS2simulatorhasbeenusedtoevaluatetheperformanceofthe802.15.4CSMA/CAmechanismunderdifferentscenariosandtovalidatetheaccuracyoftheproposedmodel.
简介:Mediumaccesscontrol(MAC)protocolssuchasIEEE802.11areusedinwirelessnetworksforsharingofthewirelessmedium.Therandomnatureoftheprotocoloperationtogetherwiththeinherentdifficultyofmonitoringintheopenposessignificantchallenges.Allnodesareexpectedtocomplywiththeprotocolrules.But,somenodesinordertogaingreaterbenefitsmisbehavebynotcomplyingwiththerules.Onesuchselfishmisbehavioriswaitingforsmallerback-offintervalswhencomparedtotheothernodesinthesamesubnet.Suchselfishmisbehaviorisbeingtackledinthispaper.Adiagnosisschemeandapenaltyschemearebeingproposedforovercomingsuchselfish-misbehavioratMAClayerofmobileadhocnetworkswhichcouldbeextendedtoothertypesofnetworksalso.