学科分类
/ 6
120 个结果
  • 简介:Apowerallocationschemeformulti-usermultiple-inputmultiple-outputorthogonalfrequencydivisionmultiplexing(MIMO-OFDM)systemswithchannelstateinformation(CSI)ontransmitterandreceiverispressed.Multi-userpowerallocationcanbedecoupledintosingleuserpowerallocationthroughoutnullspacemappingofmulti-userchannelandpowerallocationcanbeperformedthroughoutspatial-spectralwater-fillingforperuser.Todealwithmoreusersinsystemandfadingcorrelation,schedulingisperformedtomaintainthegainofpowerallocation.Theproposedschemecansubstantiallyimprovesystem'sspectralefficiencywithlowomplexity.Simulationresultsvalidatetheaccuracyoftheoreticanalyses.

  • 标签: 功率分配 MIMO-OFDM系统 多用户信息理论 无线资源管理
  • 简介:Analgorithmofhighlymaneuveringtargettrackingisproposedtosolvetheproblemoflargetrackingerrorcausedbystrongmaneuver.Inthisalgorithm,anewestimator,namedasmulti-parameterfusionSinger(MF-Singer)modelisderivedbasedontheSingermodelandthefuzzyreasoningmethodbyusingradialaccelerationandvelocityofthetarget,andappliedtotheproblemofmaneuveringtargettrackinginstrongmaneuveringenvironmentandoperatingenvironment.ThetrackingperformanceoftheMF-Singermodelisevaluatedandcomparedwithothermanueveringtrackingmodels.ItisshownthattheMF-Singermodeloutperformsthesealgorithmsinseveralexamples.

  • 标签: maneuvering target MULTI-PARAMETER FUSION SINGER (MF-Singer)
  • 简介:Inthispaper,weproposeadynamicmulti-descriptorfusion(DMDF)approachtoimprovingtheretrievalaccuracyof3-dimensional(3D)modelretrievalsystems.First,anindependentretrievallistisgeneratedbyusingeachindividualdescriptor.Second,weproposeanautomaticrelevant/irrelevantmodelsselection(ARMS)approachtoselectingtherelevantandirrelevant3Dmodelsautomaticallywithoutanyuserinteraction.Aweighteddistance,inwhichtheweightassociatedwitheachindividualdescriptorislearntbyusingtheselectedrelevantandirrelevantmodels,isusedtomeasurethesimilaritybetweentwo3Dmodels.Furthermore,adescriptor-dependentadaptivequerypointmovement(AQPM)approachisemployedtoupdateeveryfeaturevector.Thissetofnewfeaturevectorsisusedtoindex3Dmodelsinthenextsearchprocess.Four3DmodeldatabasesareusedtocomparetheretrievalaccuracyofourproposedDMDFapproachwithseveraldescriptorsaswellassomewell-knowninformationfusionmethods.ExperimentalresultshaveshownthatourproposedDMDFapproachprovidesapromisingretrievalresultandalwaysyieldsthebestretrievalaccuracy.

  • 标签: 三维模型检索 描述符 3D模型 信息融合方法 特征向量 多特征融合
  • 简介:在这份报纸,二功能的轻来源被推荐。它能两个都放大轻力量并且使解调波长信号。它的产量力量1000倍高于传统的宽带光来源(BBS),它能使解调由处于1550nm的状况在带宽范围的30nm扫描波长的信号中央波长。这种轻来源有效地在FBG的更多点测量解决光能供应的问题并且简化察觉到测量的结构。CLC数字TP211.6

  • 标签: 双功能光源 FBG 多点传感系统 光纤光栅 波分复用
  • 简介:Amemeticalgorithm(MA)foramulti-moderesourceconstrainedprojectschedulingproblem(MRCPSP)isproposed.WeuseanewfitnessfunctionandtwoveryeffectivelocalsearchproceduresintheproposedMA.Thefitnessfunctionmakesuseofamechanismcalled'strategicoscillation'tomakethesearchprocesshaveahigherprobabilitytovisitsolutionsarounda'feasibleboundary'.Oneofthelocalsearchproceduresaimsatimprovingthelowerboundofprojectmakespantobelessthanaknownupperbound,andanotheraimsatimprovingasolutionofanMRCPSPinstanceacceptinginfeasiblesolutionsbasedonthenewfitnessfunctioninthesearchprocess.AdetailedcomputationalexperimentissetupusinginstancesfromtheprobleminstancelibraryPSPLIB.ComputationalresultsshowthattheproposedMAisverycompetitivewiththestate-of-the-artalgorithms.TheMAobtainsimprovedsolutionsforoneinstanceofsetJ30.

  • 标签: 基因算法 调度问题 多模式 资源受限 文化 适应度函数
  • 简介:Thewide-swathmethodbasedonmulti-receiverisanovelandhighlyaccuratewide-swathmethod,whichrequiresaverypreciseviewangle.Theestimatedanglehaserrorbecauseoftheatmosphererefraction,angleerrorofviewandtargetheight.Amethodisproposedinthispapertoestimatetheangleerrorfromthereturnsignal.Themethodmakesuseoftherelationshipbetweentheviewangleerrorandthesignalcorrelationofthesubswathstoestimatetheangleerror.Theprecisionofthismethodisanalyzedbythelawofgreatnumberanditturnsouttobeindirectproportiontotherootsquarenumberofaveraging.Thesimulationresultisgivenandtheangleprecisionis0.025°.

  • 标签: 人造孔径雷达 SAR 多接受器 误差估计
  • 简介:AMinimizingIntermediateMulticastRoutingprotocol(MIMR)isproposedfordynamicmulti-hopadhocnetworks.InMIMR,multicastsessionsarecreatedandreleasedonlybysourcenodes.Ineachmulticastsessionprocess,thesourcenodekeepsalistofintermediatenodesanddestinations,whichisencapsulatedintothepacketheaderwhenthesourcenodesendsamulticastpacket.Nodesreceivingmulticastpacketsdecidetoacceptorforwardthepacketaccordingtothelist.Dependingontopologymatrixmaintainedbyunicastrouting,theshortestvirtualhierarchyroutingtreeiscon-structedbyimprovedDijkstraalgorithm.MIMRcanachievetheminimumnumberofintermediatenodes,whicharecomputedthroughthetree.Nocontrolpacketistransmittedintheprocessofmul-ticastsession.Loadofthenetworkislargelydecreased.ExperimentalresultshowsthatMIMRisflexibleandrobustfordynamicadhocnetworks.

  • 标签: 动态AD-HOC网络 组播路由 多跳频 节点
  • 简介:Uncertainandhesitantinformation,widelyexistinginthereal-worldqualitativedecisionmakingproblems,bringsgreatchallengestodecisionmakers.Hesitantfuzzylinguistictermsets(HFLTSs),aneffectivelinguisticcomputationaltoolinmodelingandelicitingsuchinformation,havehencearousedmanyscholars’interestsandsomeextensionshavebeenintroducedrecently.However,thesemethodsarebasedonthediscretelinguistictermframeworkwiththelimitedexpressiondomain,whichactuallydepictqualitativeinformationusingseveralsinglevalues.Therefore,itishardtoensuretheintegrityofthesemanticsrepresentationandtheaccuracyofthecomputationresults.Todealwiththisproblem,asemanticsbasisframeworkcalledcompletelinguistictermset(CLTS)isdesigned,whichadoptsaseparationstructureoflinguisticscaleandexpressiondomain,enrichingsemanticsrepresentationofdecisionmakers.Onthisbasistheconceptoffuzzyintervallinguisticsets(FILSs)isputforwardthatemploystheintervallinguistictermwithprobabilitytoincreasetheflexibilityofelicitingandrepresentinguncertainandhesitantqualitativeinformation.Forpracticalapplications,afuzzyintervallinguistictechniquefororderpreferencebysimilaritytoidealsolution(FILTOPSIS)methodisdevelopedtodealwithmulti-attributegroupdecisionmaking(MAGDM)problems.Throughthecasesofmovieandenterpriseresourceplanning(ERP)systemselection,theeffectivenessandvalidityoftheproposedmethodareillustrated.

  • 标签: hesitant FUZZY SETS MULTI-ATTRIBUTE group decision
  • 简介:反碰撞的技术是在收音机频率鉴定(RFID)的一个关键点系统。避免数据碰撞,有二条途径:阿罗哈基于算法,二进制树(BT)基于算法。然而,这些不能完全解决碰撞问题,特别当标签数量大,标签标志长时。在这篇文章,我们在场一个多分支询问树(MBQT)协议基于平衡的不完全的块设计(BIBD),代码,和使用16位向量作为RFID的询问前缀符号源于BIBD阅读器。与常规反碰撞算法相比,理论上的分析和模拟证明建议协议改进鉴定效率。

  • 标签: 无线频率识别系统 BIBD MBQT 通信技术
  • 简介:Theparallelinterferencecancellationformulti-carrierDS-CDMA(whichistermedFDC-PIC)isproposedbyintegratingfrequencydiversitycombination.ThesimulationsaremadeoverFDC-PICwithrespecttodifferentdecisionways-hard,softandlineardecisions,respectively,andweconcludethatFDC-PICacquiressuperiorperformanceimprovementovercorrelationreceptionofmulti-carrierDSCDMA.Withanincreaseininterferencecancellationstages,thesystemperformanceisimprovedfurther.Theinitial2stagesbringaboutthemostdominantperformanceimprovement,butuptothe3rdstagethesystemperformanceisimprovedlittle.ItisalsoshownbythesimulationresultsthatFDC-PICwithsoftdecisionwouldexhibitthebestperformancewithahighimplementationcomplexity,whileFDC-PICwithlineardecisionacquiresperformancecomparabletothatofFDC-PICwithsoftdecisionwithareduced-complexityifthenumberoftheinterferencecancellationstagesisthesame,whichindicatesthatFDC-PICwithlineardecisionhasoptimalperformance/complexitytradeoffandthereforewillbesuitableforpracticalapplicationinfuture.

  • 标签: DS-CDMA 码分多址 通信系统 多载波信号
  • 简介:Basedontheelectromagneticfieldtheory,theopticalsignaltransmissioncharacteristicsininput/outputwaveguides,slabwaveguidesandarrayedwaveguidesofthearrayedwaveguidegrating(AWG)multi/demultiplexerareanalyzed.TherelationshipbetweenthephysicalparameterssuchasgeometrysizesandrelativerefractiveindexinAWGmulti/demultiplexerandtheopticalsignaltransmissioncharacteristicsarediscussed.ThistheoreticalstudycanbeusedforoptimizingthedesignandimprovingtheperformanceoftheAWGmulti/demultiplexer.

  • 标签: 波导 光信号传输 阵列波导光栅 密集波分复用 光纤通信
  • 简介:Inthispaper,anAntColonySystem(AC)basedheuristicalgorithmispresentedtofindthemulti-constraineddynamicQualityofService(QoS)multicastrouting.WealsoexplorethescalabilityoftheACalgorithmandmulticasttreebyusing"Pull"modeinsteadof"Push"mode,andtheimprovementonthetimecomplexityofACalgorithmbyusinganewdatastructure,I.e.,apointerarrayinsteadoftheprevious"matrix"structure.Ourextensivetestsshowthatthepresentedalgorithmcanfindtheglobaloptimumorsuboptimum,andhasagoodscalabilitywithdynamicadaptationtothechangeofmulticastgroup,andgivesbetterperformanceintermsofthetotalcostthanothertwoalgorithms.

  • 标签: 计算机网络技术 蚂蚁群体系统 服务质量 邮件路由
  • 简介:Gettingalongwiththeimprovementofgreencommunications,theenergyefficiency(EE)ofwirelessnetworkbecomesmoreandmoreimportant.However,inmulti-relay-assistedsystems,therelatedworkobviouslydependsontheend-to-endperformance,whereasEEofrelayshasnotattractedenoughattention.Theauthorsproposeanorthogonalfrequencydivisionmultiplexing(OFDM)multi-relaysystembasedonamplifyandforward(AF)mode.TakingincorporatingEEandremainingenergyasfactor,decisioncriteriaofattendingcooperationisdesigned.TheEEbasedasynchronouspoweriterationmethodispresented,andtheexistenceandconvergenceofnashequilibrium(NE)isproven.Furthermore,ajointalgorithminsubcarrierpairing,relayselectionandpowerallocationisgiven.Geneticalgorithm(GA)anditerationmethodareintegratedtoimprovetheconvergencespeedadditionally.SimulationdemonstratestheobviousimprovementofEE,decreaseofpowerconsumptionandincreaseoflifetimeinrelaysofthisalgorithmwiththeconstraintofminimumdatatransmissionrate.

  • 标签: 中继系统 功率分配 合作网络 OFDM 能源效率 异步迭代法
  • 简介:Aimingattheconceptof'diagnosis',asimpleandeffectivebroadbandradarcrosssection(RCS)measurementsystemisconstructed,andsomemulti-dimensionalscatteringpropertiesdiagnosistechniquesarepresentedbasedonthesystem.Firstly,astepped-frequencysignalisemployedtoachievehighrangeresolution,combiningwithavarietyofsignalprocessingtechniques.Secondly,cross-rangeresolutionisgainedwitharotatingtable,andthehigh-resolutiontwo-dimensional(2-D)imagingofthescalemodelisobtainedbythemicrowaveimagingtheory.Finally,tworeceivingantennaswithasmalldistanceinaltitudeareused,andthethree-dimensional(3-D)heightdistributionofscatteringpointsonthescalemodelisextractedfromthephaseofimages.Sometypicalbodiesandascaleaircraftmodelarediagnosedinananechoicchamber.Theexperimentalresultsshowthat,afterscalingwithametalsphere,theaccurateonedimensional(1-D)RCSpatternofthemodelisobtained,andithasalargedynamicrange.Whenthebandwidthofthetransmittingsignalis4GHz,theresolutionofthe2-Dimagecanreachto0.0375m.The3-Dheightdistributionofscatteringpointsisgivenbyinterferometricmeasurement.Thispaperprovidesafeasiblewaytoobtainhigh-precisionscatteringpropertiesparametersofthescaleaircraftmodelinaconventionalrectangularanechoicchamber.

  • 标签: 诊断系统 散射特性 飞机模型 消声室 多维 高距离分辨率
  • 简介:Thispaperproposesanantennadesignconcepttoachieveamulti-reconfigurableband-notchantennabyusingasetofmicroswitches.Theproposedideawasprovedbythedesignofthecoplanarwaveguide(CPW)-fedslotantenna.Thesampledesigngivesawidebandantennatheimpedancebandwidthofwhichcoversthefrequencyrangedfrom1.9GHzto6.55GHz.Theantennacouldbeconfiguredtoworkeitherinsingle-bandmodeorinoneofthedefineddual-bandmodes.

  • 标签: Antenna BAND-NOTCHED COPLANAR waveguide (CPW) RECONFIGURABLE
  • 简介:Anovelhorizontalpush-pullmulti-substrateepitaxyboatwiththreeseparatecellsisintroducedinthisarticle,withmulti-substrateLPEprocessingisfeasibleinhorizontalLPEfurnace.TheprocessesofLPEAlxGa1-xAs/GaAssolarcellsarestudiedandtheefficiencyofthesolarcellsachieved19.8%(AM0,25℃,120mW/cm^2).

  • 标签: 漏相外延 半导体材料 单晶体 太阳能电池
  • 简介:mc2llvmisaprocess-levelARM-to-x86binarytranslatordevelopedinourlabinthepastseveralyears.Currently,itisabletoemulatesinglethreadedprograms.Weextendmc2llvmtoemulatemulti-threadedprograms.Ourmaintaskistoreconstructitsarchitectureformulti-threadedprograms.Registermapping,codecachemanagement,andaddressmappinginmc2llvmhaveallbeenmodified.Inaddition,tofurtherspeeduptheemulation,wecollecthotpaths,aggressivelyoptimizeandgeneratecodeforthematruntime.Additionalthreadsareusedtoalleviatetheoverhead.Thus,whenthesamehotpathiswalkedthroughagain,thecorrespondingoptimizednativecodewillbeexecutedinstead.Inourexperiments,oursystemis8.8XfasterthanQEMU(quickemulator)onaveragewhenemulatingthespecifiedbenchmarkswith8guestthreads.

  • 标签: 二进制代码 多线程程序 程序使用 缓存管理 动态翻译 共享
  • 简介:Afuzzyparticleswarmoptimization(PSO)onthebasisofelitearchivingisproposedforsolvingmulti-objectiveoptimizationproblems.First,anewperturbationoperatorisdesigned,andtheconceptsoffuzzyglobalbestandfuzzypersonalbestaregivenonbasisofthenewoperator.Afterthat,particleupdatingequationsarerevisedonthebasisofthetwonewconceptstodiscouragetheprematureconvergenceandenlargethepotentialsearchspace;second,theelitearchivingtechniqueisusedduringtheprocessofevolution,namely,theeliteparticlesareintroducedintotheswarm,whereastheinferiorparticlesaredeleted.Therefore,thequalityoftheswarmisensured.Finally,theconvergenceofthisswarmisproved.TheexperimentalresultsshowthatthenondominatedsolutionsfoundbytheproposedalgorithmareuniformlydistributedandwidelyspreadalongtheParetofront.

  • 标签: 多物镜系统 最佳化设计 粒子群 模糊计算
  • 简介:磁电机眼(瞬间)与微波magnetostatic波浪(MSW)指导光波浪联合同时由信号能导致的多重收音机频率(RF)激动RF信号的multifrequency衍射效果然后并行处理能被衍射效率(Des)是的特征使用认识到近似在里面到RF信号紧张和衍射角度的直接比例与在线性瞬间相互作用区域以内的相应RF信号的频率有关。在这份报纸,学习了是在一阶的瞬间相互作用近似的multifrequency瞬间布拉格衍射,并且获得是为原则衍射效率(PDE)的近似分析表示。另外,提出基于单个频率的衍射是RF信号的相对紧张的一个平行成像方法。由计算和分析,相对错误是为在内的三个RF信号的盒子的不超过0.3dB60MHz的频率空间,这被显示出。

  • 标签: 平行光谱分析 声波 布拉格衍射效率 无线频率信号