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131 个结果
  • 简介:InHL-2Atokamak,aprogramtogetthedatafromthevacuummeterhasbeendevelopedin2003.Theprogramisusedtoreadandrecordthedataoftheneutralgaspressureduringtheexperiment.Sohowtocommunicatebetweenalocalcomputerandthevacuummeterviaserial-portcommunicationisintroducedinthispaper.ThearchitectureofthesystemisshowninFig.1.

  • 标签: 真空检测仪 串行通信 应用编程接口函数 HL-2A 中性气体 压强
  • 简介:InthisarticlewewillintroducethesystemstructureofamodelbuiltforBESdatamanagementandstorageaswellasthebasicmethodsonhowtoestablishthesystem.Additionallytheanalysisofthedatastructure,thedataprocess,theselectionofexperimentalprogram,theimagemanipulationandthekeytechniqueswillbediscussedindetail,Themodelimplementsthesetupofthesystemenvironmentandallthosefunctionsfromdataloading,databasecresting,dataaccessing,remotedataprocesstodatafiguring.

  • 标签: BES实验 数据存储 数据分析 数据处理
  • 简介:Thenecessitytodistributethedataoverthewideareanetwork(WAN)tothephysicists'homeinstituteswillincrease,andtheeffectiveutilizationofthenetworkbecomescrucial,However,networksinthefutureWANwilltypicallyhavealargebandwidthatanorderofgigabitpersecond,withalatencyofseveralhundredssecondssothatthelargebandwidth-delayprodeuctextendstotensofmegabytesandnumerousproblemsareencountered.suchnetworksarecalled"longfatnetworks(LFNs)"Inordertostudythedatatransferoperatingonalongfatnetwork,wehavebuiltthePCclustersconnectedwiththerouterwhichcansimulatebandwidthlimitations.delays,packetlosses,andmultipatheffects.thisrouterisrunningonFreeBSDwithDUMMYNETkerneloption.Onthesemachineswehavemeasuredtheperformanceofthebulkdatatransfterwithnumerousconditionsandstudiedtheeffecienttransftermethods.

  • 标签: 广域网 数据传输 PC FARM
  • 简介:Afterlessthanayearofoperation,theBaBarexperimentatSLAChascollectedalmost100millionparticlecollisioneventsinadatabaseapproaching165TB.Around20TBofdatahasbeenexportedviatheInternettotheBaBarregionalcenteratIN2P3inLyon,France,andaround40TBofsimulateddatahasbeenimportedfromtheLawrenceLivermoreNationalLaboratory(LLNL),BaBarCollaboratorsplantodoubledatacollectioneachyearandexportathirdofthedatatoIN2P3.SowithinafewyearstheSLACOC3(155Mbps)connectionwillbefullyutilizedbyfiletransfertoFrancealone.Upgradestoinfrastructureisessentialanddetailedunderstandingofperformanceissuesandtherequirementsforreliablehighthroughputtransfersiscritical.Inthistalkresultsfromactiveandpassivemonitoringanddirectmeasurementsofthroughputwillbereviewed.Methodsforachievingtheambitiousrequirementswillbediscussed.

  • 标签: 粒子物理学 BaBar实验 高数据流网络
  • 简介:Thisarticleisaboutapieceofmiddleware,allowingtoconvertadumptapebasedTertiaryStorageSystemintoamultipetabyterandomaccessdevicewiththousandsofchannels.Usingtypicalcachingmechanisms,thesoftwareoptimizestheaccesstotheunderlyingStorageSystemandmakesbetteruseofpossiblyexpensivedrivesandrobotsorallowstointegratecheapandslowdeviceswithoutintroducingunacceptableperformancedegadation.Inaddition,usingthestandardNFS2protocol,thedCacheprovidesauniqueviewintothestoragerepository,hidingthephysicallocationofthefiledata,cachedortapeonly.BulkdatatransferissupportedthroughthekerberizedFTPprotocolandaC-API,providingtheposixfileaccesssemantics,Datasetstaginganddiskspacemanagementisperformedinvisiblytothedataclients.TheprojectisaDESY,FermilabjointefforttoovercomelimitationsintheusageoftertiarystorageresourcescommontomanyHEPlabs.ThedistributedcachenodesmayrangefromhighperformanceSGImachinestocommodityCERNLinux-IDElikefileservermodels.Differentcachenodesareassumedtohavedifferentaffinitiestoparticularstoragegroupsorfilesets.AffinitiesmaybedefinedmanuallyorarecalculatedbythedCachebasedontopologyconsiderations.Cachenodesmayhavedifferentdiskspacemanagementpoliciestomatchthelargevarietyofapplicationsfromrawdatatouseranalysisdatapools.

  • 标签: dCahe 高速缓冲存储器 数据存储系统
  • 简介:TheALICEdetectoratLHC(CERN),willrecordrawdataatarateof1.2Gigabytespersecond.TryingtoanalyseallthisdataatCRNwillnotbefeasible.AsoriginallyproposedbytheMONARCproject,dtacollectedatCERNwillbetransferredtoremotecentrestousetheircomputinginfrastructure,Theremotecentreswillreconstructandanalysetheevents.andmakeavailabletheresults.Thereforehigh-ratedatatransferbetweencomputingcentres(Tiers)willbecomeofparamountimportance.ThispaperwillpresentseveralteststhathavebeenmadebetweenCERNandremotecentresinPadova(Italy),Torino(Italy),Catania(Italy),Lyon(France),Ohio(UnitedStates),Warsaw(Poland)andCalcutta(India),Thesetestsconsisted,inafirststage,ofsendingrawdatafromCERNtotheremotecentresandback,usingaftpmethodthatallowsconnectionsofseveralstreamsatthesametime.Thankstothesemultiplestreams,itispossilbletoincreasetherateatwhichthedataistransferred.Whileseveral"multiplestreamftpsolutions"alreadyexist,ourmethodisbasedonaparallelsocketimplementationwhichallows,besidesfiles,alsoobjects(oranylargemessage)tobesendinparallel.Aprototypewillbepresentedabletomanagedifferenttransfers.Thisisthefirststepofasystemtobeimplementedthatwillbeabletotakecareoftheconnectionswiththeremotecentrestoexchangedataandmonitorthestatusofthetransfer.

  • 标签: 程序设计 数据传输程序 传输监视
  • 简介:ATLAS[1]hasrecentlyjoinedGaudi,anopenprojecttodevelopadataprocessingframeworkforHEPexperiments[2],ThedatamodelisoneoftheareaswhereATLAShasextendedmoretheoriginalGaudidesigntomeettheexperiment'sownrequirments.ThispaperdescribesStoreGate,thefirstimplementationoftheATLASDataModel.

  • 标签: 高能物理学 数据模型 ATLAS软件
  • 简介:ARGO-YBJ,aChinese-ItalianCollaboration,isgoingtofinishthefirststepoftheinstallationofthiscosmicraytelescopeconsistinginasinglelayerofRPCs,placedat4300m.elevation,inTibet,Thedetectorwillprovideadetailedspace-timepictureoftheshowersfront,initiatedbyprimariesofenergiesintherange10GeV-500TeV.Thedatatakingwillstartatthebeginningof2002withafractionofthedetectorinstalled.willbeupgradedtwotimes,beingcompletedattheendof2003,Inthispaperwebrieflydescribethedataflow,thetriggerorganization,thethreeoperationalstepsindatatakingandthecomputingmodeltoprocessthedata.theneedofremotemonitoringoftheexperimentwillbetouchedupon.TheprocessingpowerfortherawdatareconstructionandfortheMonteCarlosimulationisreported.

  • 标签: ARGO实验 数据收集 数据处理
  • 简介:Inhigh-energyphysics,terabyteandsoonpetabyte-scaledatacollectionsareemergingascriticalcommunityresources.Anewclassof"DataGrid"infrastructureisrequiredtosupportdistributedaccesstoandanalysisofthesedatasetsbypotentiallythousandsofusers.DataGridtechnologyisbeingdeployedinnumerousexperimentsthroughcollaborationssuchastheEUDataGrid,theGridPhysicsNetwork,andtheParticelPhysicsDataGrid[1],TheGlobusToolkitisawidelyusedsetofservicesdesignedtosupportthecreationoftheseGridinfrastruncturesandapplications,InthispaperwesurveytheGlobustechnologiesthatwillplayamajorroleinthedevelopmentanddeploymentfortheseGrids.

  • 标签: 高能物理 Globus工具 数据密集科学
  • 简介:AthenaisthecommonframeworkusedbytheATLASexperimentforsimulation,reconstruction,andanalysis,Bydesign,Athenasupportsmultiplepersistenceservices,andinsulatesusersfromtechnology-specificpersistencedetails.AthenausersandevenmostAthenapackagedevelopersshouldneitherknownorcarewhetherdatacomefromthegridorfromlocalfilesystems.norwhetherdataresideinobjectdatabases,inROOTorZEBRAfiles,orinASCIIfiles.InthispaperwedescribehowAthenaapplicationsmaytransparentlytakeadvantageofemergingservicesprovidedbygridsoftwaretoday-howdatageneratedbyAtheajobsareregisteredingridreplicacatalogsandothercollectionmanagementservices,andthemeansbywhichinputdataareidentifiedandlocatedinagrid-awarecollectionmanagementenvironment.Weoutlineanevolutionarypathtowardincorporationofgrid-basedvirtualdataservices,wherebylocatingdatamaybereplacedbylocatingarecipeaccordingtowhichthatdtamaybegenerated.Severalimplementationscenarios,rangingfromlowlevelgridcatalogservices(e.g.,fromGlobus)throughhigher-levelservicessuchastheGridDataManagementPilot(underdevelopmentaspartoftheEuropeanDataGridporject,incollaboration,withtheParticlePhysicsDataGrid)tomoreconventionaldatabaseservices,andacommonarchitecturetosupportthesevariousscenarios,arealsodescribed.

  • 标签: ATLAS实验 粒子物理学 虚拟数据
  • 简介:TheANTAREScollaborationisbuildingadeepunderwaterneutrinotelescopetobeimmersedintheMediterraneanSea40kmofftheFrenchcoast.ThisdetectorwillbeabletodetecttheCherenkovlightemittedbymuonsproducedinneutrinointeractionsusingathree-dimensionalmatrixofopticalsensors,Thetelescopewillbemadeofnearly1000oftheseelementaryunitsdistributedoverawideareaofabout0.1km2atanaveragedepthof2400mInordertoreachasub-nanosecondresolutiononlighpulsedetection,signalsfromallOMsareanalyzedanddigitizedlocallybeforebeingsenttoshorethrougha50kmelectro-opticalcable,Front-endelectronics,timealignment(clockdistribution),TriggeringanddataacquistitionforsuchalargeandremotedetectorrepresentarealhallengeandrequiredconsiderableR&Dstudies,Thetechnicalsolutionsadoptedbythecollaborationwillbedescribedandtheirperformancesdiscussed.

  • 标签: 深水下中微中子实验 触发器 数据收集
  • 简介:FormorethanoneyeartheCLEOⅢexperimentattheCornellelectronpositronstorageringCESRhasaccumulatedPhysicsdatausinga4layersiliconvertexdetectorandanovelringimageCherenkovdetector,alongwithaconventionalDriftchamber,E.M.calorimeterandmuonchambers.BythetimeofCHEP2001theexperimenthasaccumulated10fb^-1ofdata,Thereadoutandmonitoringsystemscontrol,ca.400000electronicchannels.Detectorconfiguration.dataqualityandcomponentmonitoring,runcontrolareonlysomeoftheSlowControltasksthathavetobeperformed.DeployingindustrystandardssuchasCORBA(inter-platformcommunication)Java(remoteaccessviaWebbrowser)andObjectivity(eventandconstantsdatabse)asbuildingblocksofthecomputernetworkhasbeenofcentralimportance.Objectorienteddesignhasenabledtheseamlessintegrationofthemanyindividualcomponents.Inourpresentationwewilldescribeexperienceswiththisdistributedcontrolsystemandgiveareportofthemeasurestakentoobtainahighsystemavailability.

  • 标签: CLEOⅢ实验 计算机控制系统 数据获取
  • 简介:Backgroundknowledgeisimportantfordatamining,especiallyincomplicatedsituation.Ontologicalengineeringisthesuccessorofknowledgeengineering.Thesharableknowledgebasesbuiltonontologycanbeusedtoprovidebackgroundknowledgetodirecttheprocessofdatamining.ThispapergivesacommonintroductiontothemethodandpresentsapracticalanalysisexampleusingSVM(supportvectormachine)astheclassifier.GeneOntologyandtheaccompanyingannotationscomposeabigknowledgebase,onwhichmanyresearcheshavebeencarriedout.MicroarraydatasetistheoutputofDNAchip.WiththehelpofGeneOntologywepresentamoreelaborateanalysisonmicroarraydatathanformerresearchers.Themethodcanalsobeusedinotherfieldswithsimilarscenario.

  • 标签: 本体工程 微阵列数据 基因表达 分类分析 数据挖掘
  • 简介:SNDisasphericalnon-magneticdetector,whichoperatedsince1996atVEPP-2Melectron-positroncolliderinNovosibirsk.NowVEPP-2McolliderisdismantledtobereplacedbyanewVEPP-2000machinewithhigherenergyandluminosity.TheSNDdetectorisalsoperformingupgradeofitssubsystemsincludingelectronics,andsoftware,ExpectedsubstantialgrowthofeventsdataflowrequiresradicalchangesintheDataAcquisition(DAQ)systemsoftware.ThispaperdescribestheSND2000softwarearchitecrureanditsprincipalcomponents.Firstthemaineventsflowprocessuingcomponentsareconsidered-thereadoutprocessandtheL3-triggerfarm.AfterprocessingbyL3theeventsflowiseitherloggedtotapeorfedtocalibrationandslowcontrolprocess.Usingauxiliarycontrolandservicesoftwarecomponents,whicharealsodescribed.performsthemanagementoftheseactivities.

  • 标签: SND实验 电子正电子碰撞 无磁探测器
  • 简介:TheCDFcollaborationattheFermilabTevatronanalysesproton-antiprotoninteractionsatacenter-of=massenergyof2TeV.duringthethecolliderrunstartingthisyeartheexperimentexpectstorecord1Petabyteofdataandassociateddatasamples,TheDataHandling(DH)systemhasonlineandofflinecomponents.TheDHofflinecomponentprovidesaccesstothestoreddata,tostoredreconstructionoutput,tostoredMonte-Carlodatasamples,anduserowneddatasamples.Itservesmorethan450physicistsofthecollaboration.TheextrarequirementstotheofflinecomponentoftheDataHandlingsystemaresimplicityandconvenienceforusers.Morethan50millioneventsoftheCDFRunIIdatahavebeenalreadyprocessedusingthissystem.

  • 标签: CDF 数据处理系统 质子反质子相互作用
  • 简介:ThelongtermaccessibilityofitsdataisanimportantconcernoftheDELPHIcollaboration.Itisourassumptionthatthestorageofthedataitselfwillbeaminorissueduetotheprogressinstoragetechnologies.ThereforeDELPHIfocusesonareorganisationofthedata,whichshouldprovideaflexibleandcoherentframeworkforphysicsanalysisinthefuture.ThispaperdescribesthecurrentstatusoftheIDEA(ImprovedDElphiAnalysis)projectwhichwillensureusabilityofDELPHIdataforfuturegenerationsofphysicists.

  • 标签: 高能物理实验 DELPHI数据 IDEA项目