简介:TopicsofcurrentinterestInthelastissueofthisjournal“ELECTRICITY,CSEE”areportwaspresentedontheInternationalConferenceonPowerSystemTech-nology’91wherespecialistsfrom15countriesweregatheredtogethertodiscusstopicsofcommoninterest.Severaloutstandingproblemsdeservespecialreport.Forinstance,thegreenhouseproblemwasreportedinthisissueunderthecolumnofpowerandenvironment.Theoperator’strainingsimulatorisreportedinaspecialarticleinthisissue.Sinceaseriesoflargescaleblackoutsoccurredinseveralcountries,particularlythe1977NewYorkCityblackout,peoplerealizedthatoperatorsinthemodemfullycomputerizedandautomatedcontrolcenterneedconstantpracticeonasimulator,sothattheycanbefullypreparedtohandlesuddenattacksofseveredisturbances.Thecurrentprob-lemsandviewsfromseveralcountriestakingpartinthepaneldiscussionwerereportedinthisissue.Somenewtechniquesattractingmuchattentionfromresearchersinthefieldofpowersystemtechnology,suchasfuzzysystems,ExpertSystems,ArtificialNeuralNetworksandPetriNetswerediscussedtoquitesomeextentinthisconference.Theyarealsoreportedinthisissue.Morespecialsubjectswillbereportedinlaterissues.(Ed.)
简介:ThispaperputsforwardanewfaultdiagnosismodelbasedonPetrinet.Inthisnewfaultdiagnosismethod,anassociatedtreeisfirstdefinedtodescribethelogicaccordingtotheprotectionsandcircuitbreakers.AfterthataPetrinetdiagnosismodelcomesintobeingandtheprecisediagnosisofpowergridelementscanberealizedatthesametime.Thesimulationresultsgiveninthispaperillustratethatthisfaultdiagnosismethodcanmakearapiddiagnosisincomplexfaultsituationandgiveaccurateresultstopowergridfaultdiagnosis.
简介:Multimediasynchronizationisasignificantrequirementfordistributedmultimediaapplications.Inthispaper,amultimediasynchronizationmodelbasedontimedPetrinetsispresented.Usingthismodelonecangivetheabstractionandformaldescriptionformultimediaobjectcompositionswithtime-constrainedrelations.Algorithmsforasynchronoususerinteractionsarealsopresented.
简介:摘要:为了优化我国铁路货运业务流程,促进铁路货运业务的良性发展,对铁路货运流程的优化应当综合利用信息化技术,构建智能铁路电子商务平台,形成一个综合服务体系。采用层次化建模方法对业务流程进行模型建立与分析,找出模型中的不合理结构,应用关联矩阵重组优化规则对模型进行优化。最后以时间为参考因素,对优化前后的业务流程进行比较。实验结果表明改进后的货运流程在时间效率方面得到了明显的提升。
简介:Inthispaper,Petrinetstechniqueisintroducedintomobileadhocnetworks(MANET)andapacket-flowparallelschedulingschemeispresentedusingStochasticPetriNets(SPN).Theflowingoftokensisusedingraphicsmodetocharacterizedynamicalfeaturesofsharingasinglewirelesschannel.ThroughSPNreachabilityanalysisandisomorphiccontinuoustimeMarkovprocessequations,somenetworkparameters,suchaschannelefficiencyand,one-hoptransmissiondelay,canbeobtained.ComparedwithThoseofTheconventionalperformanceevaluationmethods,theaboveparametersaremathematicalexpressionsinsteadoftestresultsfromsimulator.
简介:针对震后次生灾害的演化问题,本文采用多案例分析方法提取地震及其次生灾害事件的属性,从属性层次按照“事件类型、关键属性、从属属性、环境属性和危害评估属性”对其进行结构化描述,分析震后次生灾害事件的属性特征,绘出了震后次生灾害演化Petri网模型。在此基础上,以渐变型次生灾害事件——震后瘟疫为例,根据随机Petri网与马尔科夫链的同构关系,构建了震后瘟疫事件演化系统随机Petri网模型。最后,通过马尔科夫链及相关数学方法对震后瘟疫事件演化系统进行了评估,分析其中的均衡状态及其变动规律,验证了模型的有效性,为应对地震次生灾害事件提供科学的应急决策支持。