简介:ThispaperpresentsadaptivehybridprotocolsbasedonthedeclarativenetworkandmainlydiscussestheprincipleandrealizationoftheBayesian-estimationbasedadaptivehybridprotocolinthedeclarativenetwork,whichiswelladaptedtotheMobileAdhocNETwork(MANET).Theadaptivehybridprotocolisdesignedforadhocnetworkswhichhavecharacteristicslikeself-organizing,notrustedparty,flexibility,etc.Thenodesthatrunthehybridprotocolcanautomaticallyselectoneroutingprotocolthatissuitablefordifferentnetworkenvironment.TheBayesian-estimationbasedadaptivestrategy,thatimprovestheadaptabilityandstabilityoftheprotocol,succeedsintheRapidnet,adeclarativenetworkengine.TheresultintheRapidnetprovesthatthehybridprotocolandtheadaptivestrategyarefeasible.Theexperimentonthens-3simulator,anemergingdiscrete-eventnetworksimulator,validatesthatthisprotocolperformswellandreducescommunicationoverheads.
简介:Thispaperfocusesoninvestigatingimmunologicalprinciplesindesigningamulti-agentsecurityarchitectureforintrusiondetectionandresponseinmobileadhocnetworks.Inthisapproach,theimmunity-basedagentsmonitorthesituationinthenetwork.Theseagentscantakeappropriateactionsaccordingtotheunderlyingsecuritypolicies.Specifically,theiractivitiesarecoordinatedinahierarchicalfashionwhilesensing,communicating,decisionandgeneratingresponses.Suchanagentcanlearnandadapttoitsenvironmentdynamicallyandcandetectbothknownandunknownintrusions.Theproposedintrusiondetectionarchitectureisdesignedtobeflexible,extendible,andadaptablethatcanperformreal-timemonitoring.Thispaperprovidestheconceptualviewandageneralframeworkoftheproposedsystem.Intheend,thearchitectureisillustratedbyanexampletoshowitcanpreventtheattackefficiently.
简介:AdHoc网络是一种多跳的无线自组织网络,有着广阔的应用前景。但由于自身的复杂性,其应用和发展也面临着诸多问题。本文归纳和说明了AdHoc网络的各种应用,介绍了AdHoc网络相关产品的进展情况,分析探讨了AdHoc网络的发展趋势和有待解决的一些问题。
简介:Theabsenceofnetworkinfrastructureandopportunisticspectrumaccessincognitiveradioadhocnetworks(CRAHNs)resultsinconnectivityandstabilityproblems.Clusteringisknownasaneffectivetechniquetoovercomethisproblem.Clusteringimprovesnetworkperformancebyimplementingalogicalnetworkbackbone.Therefore,howtoefficientlyconstructthisbackboneamongCRAHNsisofinterest.Inthispaper,weproposeanewclusteringalgorithmforCRAHNs.Moreover,wemodelanovelclusterheadselectionfunctionbasedonthechannelheterogeneityintermoftransmissionranges.Tothebestofourknowledge,thisisthefirstattempttomodelthechannelheterogeneityintotheclusteringformationincognitiveradionetworks.Simulationresultsshowthattheperformanceofclusteringissignificantlyimprovedbythechannelheterogeneityconsiderations.
简介:中兴A100、A200、A300系列手机都采用美国AD模拟器件公司生产的AD6521(音频),AD6522(CPU),AD6523(中频),AD6524(频合)芯片组,使用该组芯片组的主芯片还有联想808、松下GD55,宝石680等,在实际维修中,凡使用相同主芯片的手机在部分其它元件也是可以相互代换的,有时候两部手机的不同只是元器件排列的不同以及软件和外壳不同而已,因此使用相同芯片组合的手机故障排除方法也相同或类似,难怪有行内维修师傅说,再过一段时间手机维修也就是手机芯片组合的维修,下面以中兴A系列手机为例,从维修实测的角度出发,主要谈一下不开机和无服务故障的维修思路。
简介:AMinimizingIntermediateMulticastRoutingprotocol(MIMR)isproposedfordynamicmulti-hopadhocnetworks.InMIMR,multicastsessionsarecreatedandreleasedonlybysourcenodes.Ineachmulticastsessionprocess,thesourcenodekeepsalistofintermediatenodesanddestinations,whichisencapsulatedintothepacketheaderwhenthesourcenodesendsamulticastpacket.Nodesreceivingmulticastpacketsdecidetoacceptorforwardthepacketaccordingtothelist.Dependingontopologymatrixmaintainedbyunicastrouting,theshortestvirtualhierarchyroutingtreeiscon-structedbyimprovedDijkstraalgorithm.MIMRcanachievetheminimumnumberofintermediatenodes,whicharecomputedthroughthetree.Nocontrolpacketistransmittedintheprocessofmul-ticastsession.Loadofthenetworkislargelydecreased.ExperimentalresultshowsthatMIMRisflexibleandrobustfordynamicadhocnetworks.
简介:为满足广大发烧友对高性价比放大器产品的需求,天逸最近推出了一款在音质音色上与高端的纯甲类AD-2N放大器非常接近,价格更吸引人的AD-99合并式甲类放大器。AD-99是在AD-2N放大器的基础上,对外观工艺、内部工艺及整机用料进行优化整合而推出的。即使如此,AD-99的用料也不是能省即省,在影响音质的主要通道和电源滤波部份,选用了美国BB公司的OPA2134运放、MKP聚丙稀电容、70000μF的名牌音频专用电解及500W的巨型的优质大环牛。而机器的功率输出级则采用了大电流高偏置电路以消除功率管的开关失真,更保证了纯甲类工作状态下的表现,是性价比十分高的一款放大器。