简介：UnderstandinghowtheInternetisusedbyHEPiscriticaltooptimizingtheperformanceoftheinter-labcomputingenvironment.Typicallyuserequirementshavebeendefinedbydiscussionsbetweencollaborators.However,lateranalysisoftheactualtraffichasshownthisisoftenmisunderstoodandactualuseissignificantlydifferenttothatpredicted.Passivemonitoringoftherealtrafficprovidesinsightintothetruecommunicationsrequirementsandtheperformanceofalargenumberofalargenumberofinter-communicatingnodes.ItmaybeusefulinidentifyingperformanceproblemsthatareduetofactorsotherthanInternetcongestionespeciallywhencomparedtoothermethodssuchasactivemonitoringwheretrafficisgeneratedspecificallytomeasureitsperformance.Controlledactivemonitoringbetweendedicatedserversoftengivesanindicationofwhatcanbeachievedonanetwork,Passivemonitoringoftherealtrafficgivesapictureofthetrueperformance.ThispaperwilldiscussthemethodandresultsofcollectingandanalyzingflowsofdataobtainedfromtheSLACInternetborder,TheuniquenatureofHEPtrafficandtheneedsoftheHEPcommunitywillbehighlighted.Theinsightsthishasbroughttounderstandingthenetworkwillbereviewedandthebenefitiscanbringtoengineeringnetworkswillbediscussed.

简介：Real-timevideotransportoverwirelessInternetfacesmanychallengesduetotheheterogeneousenvironmentincludingwirelineandwirelessnetworks.Arobustnetworkconditionclassificationalgorithmusingmultipleend-to-endmetricsandSupportVectorMachine(SVM)isproposedtoclassifydifferentnetworkeventsandmodelthetransitionpatternofnetworkconditions.End-to-endQuality-of-Service(QoS)mechanismslikecongestioncontrol,errorcontrol,andpowercontrolcanbenefitfromthenetworkconditioninformationandreacttodifferentnetworksituationsappropriately.TheproposednetworkconditionclassificationalgorithmusesSVMasaclassifiertoclusterdifferentend-to-endmetricssuchasend-to-enddelay,delayjitter,throughputandpacketloss-ratefortheUDPtrafficwithTCP-friendlyRateControl(TFRC),whichisusedforvideotransport.Thealgorithmisalsoflexibleforclassifyingdifferentnumbersofstatesrepresentingdifferentlevelsofnetworkeventssuchaswirelinecongestionandwirelesschannelloss.Simulationresultsusingnetworksimulator2(ns2)showedtheeffectivenessoftheproposedscheme.

简介：基于80C51单片机以及Sensiron公司的SHT11型智能化湿度/温度传感器设计了智能数字无线控制时钟,实现了精准定时校时、温湿检测、人性化录音闹铃等控制功能。

简介：设计一种基于STC89C51单片机的无线收发系统,本设计采用频率合成技术、FM调制技术及超外差解调技术,单片机对锁相环本振频率(发射43MHZ、接收53.7MHZ)锁定并通过液晶显示,本振频率在一定的范围内可调。将音频信号、咪头信号和数字英文字母信号作为调制信号,最后实现了音频、数字、英文字母等信号的重现。

简介：本文通过磁耦合共振的无线输电技术实现了对旋转LED主板的供电，并研制出一套旋转式LED点阵显示演示仪；通过STC12C5A32S2单片机实现对LED的控制和显示；通过红外通信实现对显示字符的红外操作；通过电机驱动实现LED的旋转显示。通过对旋转主板和底座主板的设计，实现了LED旋转显示的功能。该演示仪在实验和教学中起到了良好的演示效果。