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189 个结果
  • 简介:Apeer-to-peer(P2P)networkisadistributedapplicationarchitecturewhichprovidesmanyattractivefeatures,suchasavailability,self-organization,load-balancing,andanonymity.However,P2Pnetworkhascreatedsignificantproblemstonetworkoperatorsbygeneratinglargevolumesofinterautonomoussystem(inter-AS)traffic.FocusingontheBitTorrentswarmingprotocol,thispaperproposesanapproachwhichaimstoreduceP2Pgeneratedinter-AStraffic.Inparticular,theapproachcanreduceinter-AStrafficby50%to70%.Moreover,itcanimprovethedownloadingspeedby60%forthepopulartorrents.Theevaluationshowsthatcontrolledregional-basedcontentsreplicationcaneffectivelyachievethisgoal.Furthermore,theapproachisincrementallydeployable.NetworkregionsinwhichthesystemgetsdeployedcansolvetheirP2Pgeneratedinter-AStrafficproblemsautonomously,i.e.,withoutanyInternetserviceproviders-collaborationandanyrequirement,thesystemcanbedeployedintheentireInternet.

  • 标签: P2P网络 交通问题 BITTORRENT ISP 网络运营商 合作
  • 简介:Inexperimentalstudyofthetindioxidegassensor,insitusheetconductivitywasmeasuredwithultrahighvacuumfourpointresistivityprobe.Surfacecompositionandstoi-chiometryweredetectedusingXPS.FourseparatestructurephaseswereobtainedbyLEEDatdifferentannealingtemperature,andemissionwasobservedthroughoutthebandgapuptotheFermilevelwithUPS.Furthermore,effectsofannealingtemperatureanddosedoxygenpressureonthesurfacereconstruction,O/Snratio,sheetconductivity,variationoftheworkfunctionandbandbendinghavebeenalsoinvestigated.Theresultshelpustorevealtherelationshipsbetweentheelectronicandelectricalpropertiesofthematerialanditsnativedefectsstructure.Itises-peciallyusefultoprovideamorecompleteunderstandingofthebasicoperationmechanismsforsuchsensingmaterials.

  • 标签: Sensor CONDUCTIVITY STOICHIOMETRY Reconstruction ANNEALING
  • 简介:WereportthedepositionofNb2O5filmsonunheatedBK-7glasssubstratesusingremoteplasmasputteringsystem.Theremoteplasmageometryallowspseudoseparationofplasmaandtargetbiasparameters,whichofferscompletedepositionratecontrol.Usingappropriateoxygenflowrates,high-densityandlow-lossNb2O5filmsaredepositedwithratesupto0.49nm/s.Lowerdepositionrates(~0.026nm/s)canalsobeobtainedbyworkingatlowtargetcurrentandvoltageandatlowpressure.Nb2O5filmsdepositedatdifferentrateshavetherefractiveindexofabout2.3andtheextinctioncoefficientaslowas6.9×10-5.

  • 标签: 远程等离子体 溅射薄膜 亏损 薄膜沉积 速率控制 沉积速率
  • 简介:Thestructureoftheopticalwaveguideof2-bitelectroopticA/Dconverterwithproton-exchangemicroprismsisoptimizedbythefinite-differencebeampropagationmethod(FD-BPM).Theelectrodeparametersoftheconverterareoptimizedbyconformalmapping.Theoptimalparametersareahalf-wavevoltageofVπ=4.5VandabandwidthofΔf=1.4GHz.Anormalizedtransmittedpowerof69.75%isobtainedbyFD-BMPandtheoutputwaveguidegapis300μm.

  • 标签: 优化设计 数字变换器 光学波导 电磁传播
  • 简介:Finder对于任何一个Mac用户而言.它是一个最重要的软件,可以是整个Mac操作系统的象征物。对于一个软件开发人员来说Finder首先是一个用于计算资源管理的Carbon程序.更重要的是Finder能帮助应用程序更好地得到用户的使用和加强协同其他计算资源能力。无论你是一个Mac开发者或是一个需要在Mac上部署软件的用户,本文都将告诉你有关这个软件的一些深层次信息。

  • 标签: Mac操作系统 FINDER 应用程序 登陆管理 接口 信息属性
  • 简介:ThepreparationofPT/PEK-cfilmsisreportedaswellastheirdielectricandopticalproperties.Thec-axisorientationratioofthefilmsis68%.Dielectricconstantandlossfactorat10kHzisabout4.023F/mand0.003,respectively.Therefractiveindicesofthefilms,neandno,are1.6573and1.6278at0.63μmwavelength,respectively.Theopticalband-gapofthefilmwithathicknessof2.33μmisfoundtobe3.06eV

  • 标签: 定向比 电介质 PT/PEK-C薄膜 光带间隙
  • 简介:A2D-directionofarrivalestimation(DOAE)formultiinputandmulti-output(MIMO)radarusingimprovedmultipletemporal-spatialsubspacesinestimatingsignalparametersviarotationalinvariancetechniquesmethod(TS-ESPRIT)isintroduced.InordertorealizetheimprovedTS-ESPRIT,theproposedalgorithmdividestheplanararrayintomultipleuniformsub-planararrayswithcommonreferencepointtogetaunifiedphaseshiftsmeasurementpointforallsub-arrays.TheTS-ESPRITisappliedtoeachsub-arrayseparately,andinthesametimewiththeotherstorealizetheparallellytemporalandspatialprocessing,sothatitreducesthenon-linearityeffectofmodelanddecreasesthecomputationaltime.Then,thetimedifferenceofarrival(TDOA)techniqueisappliedtocombinethemultiplesub-arraysinordertoformtheimprovedTS-ESPRIT.Itisfoundthattheproposedmethodachieveshighaccuracyatalowsignaltonoiseratio(SNR)withlowcomputationalcomplexity,leadingtoenhancementoftheestimatorsperformance.

  • 标签: direction of ARRIVAL estimation (DOAE) temporal
  • 简介:0.概述近年来,中国的移动通信市场己开始从快速增长阶段进入到成熟阶段,随着3G的临近,新的运营商将会参与移动通信市场的竞争。面对日益激烈的竞争形势,中国移动作为国内移动通信市场占主导地位的运营商,如何处理现有GSM系统与3G之间的关系、制定合理的3G发展策略,以及顺利完成2G向3G过渡等,已成为面临的关键问题。

  • 标签: 中国移动 3G 策略研究 过渡 2G 移动通信市场
  • 简介:<正>2015年22日,笙科电子(AMICCOM)发表2.4GHz单向2Mbps无线发射SoC芯片,命名为A8325。A8325为A7325的SoC整合型芯片,RF效能与A7325相同。可与笙科的2.4GHzRF或SoC搭配使用。A8325的传输速度高达2Mbps,并支持FSK与GFSK调变,数字部份整合高效能的1TPipeline8051,内建8KbytesOTPMemory、1KbytesRAM,与12/8个GPIO与各种数字接口。2线式的ICE可搭配KeilC开发。

  • 标签: SOC芯片 无线发射 Hz bps PIPELINE 整合型
  • 简介:Anultra-highspeed1:2demultiplexerforopticalfibercommunicationsystemsisdesignedutilizingtheIHP0.25μmSiGeBiCMOStechnology.Thelatchofthedemultiplexercorecircuitisresearched.Basedonthecurrentmeasurementcondition,ahigh-gainandwide-bandwidthclockbufferisdesignedtodrivelargeload.Transmissionlinetheoryforultra-highspeedcircuitsisusedtodesignmatchingnetworktosolvethematchingproblemamongtheinput,outputandinternalsignals.Thetransientanalysisshowsthatthisdemultiplexercandemultiplexone100Gb/sinputintotwo50Gb/soutputs.Thechipareaofitis0.7mm×0.47mm,theinputandoutputdataarebothat400mVP-PPCMLstandardvoltagelevel,andthepowerconsumptionoftheICis900mWatthepowersupplyof-4V.

  • 标签: 集成电路 Gb 晶体管 BICMOS技术 信号分离器 超高速电路
  • 简介:已经有130多年历史的柯尼卡公司和70多年历史的美能达公司从2003年的秋天开始逐渐淡出人们的视野,真正成为“历史”,取而代之的是两者的“合壁”柯尼卡美能达(kenihminolta)。自今年1月发表经营合并以来,经过5月份股份交换合同的签定、6月份股东大会上对股份交换合同的表决认可,在8月5日通过交换股份方式实施了经营合并,10月1日实施了集团内事业的整合,日本柯尼卡株式会社和美能达株式会社的合并重组终于尘埃落定。

  • 标签: 股份 亚洲 经营 淡出 合并重组 有限公司
  • 简介:据《每日科学》报道,来自肯塔基大学、德国戴姆勒公司及希腊电子结构和激光研究所(IESL)的科学家们合作发现了一种单原子厚度的新型平面材料,该材料可替代石墨烯材料,并将推动数字技术的进步。尽管现在石墨烯备受瞩目,被认为是世界上最强韧的材料,但却有一个显见的不足——它不是半导体,这对其在数字产业的应用来说无疑是个打击。新材料由硅、硼、氮元素组成,3种元素都有重量轻、价格低、储量大的优点。此外,

  • 标签: 新材料 科学家 可替代 石墨 2D 元素组成
  • 简介:11月11日.苹果电脑公司宣布正式推出U2iPod。此举被视为苹果公司与U2乐队及环球唱片(UMG)为数码音乐新时代携手共创革新产品的一部分。这款全新的U2iPod能够容纳5000首歌曲。它拥有黑色外壳及红色的点击式转盘,背面还刻有U2乐队全体成员签名。

  • 标签: IPOD 苹果公司 数码音乐 发布 新风 掀起
  • 简介:Aterahertz(THz)polarizerandswitchstructureisproposedbasedonthephasetransitionofvanadiumdioxide(VO2).WhenVO2isintheinsulationphase,theresonancefrequenciesoftheproposedstructureare1.49THzand1.22THzforthex-andy-polarization,respectively.ItcanperformasaTHzpolarizerwithextinctionratiosof52.5dBand17dBforthey-andx-polarization,respectively;WhenVO2transformsintometallicphase,theresonancefrequencyforx-polarizationwaveshiftsfrom1.49THzto1.22THz,whilethatremainsstillforthey-polarizationcomponent.Itmeansthatthestructurecanworkasapolarization-dependentTHzswitchwithahighextinctionratioof32dB.

  • 标签: 偏振开关 太赫兹 VO2 相变 偏振消光比 多用
  • 简介:AninitialstructuredesignofMMI1×8opticalpowersplittersisreported.ThewaveguidematerialisSi-basedSiO2Ge-dopedanddepositedbyPECVDmethod.Embeddedstripstructureisimpliedinthesectiondesign.ByusingBPM-CAD,afavorableresultisobtainedthatthisdevicehasasounduniformityandfairlylowloss.Meanwhile,simulationsofdesignswithcertainchangedparametersisalsoimplementedforabetterdesignconfiguration.

  • 标签: 光功率分配 多模干扰 波导 MMI
  • 简介:因特网已成为全球最大的信息基础设施,在全球宽带化、移动化、IP化、融合化、个性化大潮中,IPv6的海量地址支持及改进的业务解析能力与PeertoPeer(P2P)对等互联及有效宽带资源共享传送能力相组合,可以期望将会对开启未来信息通信网络新时代做出新的贡献!

  • 标签: 宽带网络 IPV6 P2P 信息基础设施 信息通信网络 解析能力
  • 简介:UnipolarresistiveswitchingbehaviorsoftheZnOandAl2O3/ZnOfilmsfabricatedonflexiblesubstratesbypulselaserdepositionwerestudiedinthispaper.Thefilmsweredepositedatroomtemperaturewithoutpost-annealingtreatmentduringtheprocess.XraydiffractionresultsindicatedthatZnOfilmhasadominantpeakat(002).ScanningelectronmicroscopyobservationshowedacolumnargrainstructureoftheZnOfilmtothesubstrate.ThebilayerdeviceofAl2O3/ZnOfilmshadstableresistiveswitchingbehaviorswithagoodenduranceperformanceofmorethan200cycles,highresistiveswitchingratioofover103atareadvoltageof0.1V,whichisbetterthanthatofthesingleoxidelayerdeviceofZnOfilm.Apossibleresistiveswitchingfilamentarymodewasdemonstratedinthispaper.TheconductionmechanismsofhighandlowresistancestatescanbeexplainedbyspacechargelimitedconductionandOhmic’sbehaviors.Theenduranceofthebilayer(BL)devicewasnotdegradeduponbendingcycles,whichindicatesthepotentialoftheflexibleresistiveswitchingrandomaccessmemoryapplications.

  • 标签: FLEXIBLE PULSED laser DEPOSITION resistive switching