简介：互联网的普及和应用大幅改变了教师的课堂教学模式和学生的学习模式.本文首先介绍了物理专业实验课程的现状和在当前互联网普及应用背景下改革的必要性.然后重点阐述了基于互联网的专业物理实验课程的教学改革方案和实施方法.最后对教学改革的尝试所取得的效果和意义进行总结.

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.