服務計算基礎主講：李偉剛西北工業大學軟件與微電子學院目前一頁\總數六十五頁\編于十五點第九章語義Web服務目前二頁\總數六十五頁\編于十五點主要內容概述語義網語義Web服務目前三頁\總數六十五頁\編于十五點第一節概述目前四頁\總數六十五頁\編于十五點語義是事物的觀察者給事物本身賦予的含義，一致共享的語義構成觀察者對事物的知識，是觀察者之間互相交流的基礎。語義網通過給萬維網上的文檔(如:HTML)添加能夠被計算機理解的語義(Metadata)，從而使整個萬維網中現存的信息發展成一個巨大的全球信息庫、知識庫。語義和語義網目前五頁\總數六十五頁\編于十五點Web服務使用標準的、規范的XML進行描述，包括消息格式、傳輸協議和位置，隱藏了實現服務的細節。WSDL從句法層面對Web服務的功能進行描述，包括4個不同的方面：數據類型、消息、操作和訪問端口。這只是提供了Web服務的接口描述，對服務的行為約束和屬性描述缺乏進一步的支持。缺陷數據管理有序性與Web上信息無序性；搜索引擎查全查準要求與服務描述缺語義；信息獲取效率與Web海量動態數據。語義Web服務目前六頁\總數六十五頁\編于十五點語義Web服務的主要方法是利用Ontology來描述Web服務，通過帶有語義信息的Web服務來實現服務的自動發現，調用和組合。語義Web和Web服務是語義Web服務的兩大支撐技術。OWL-S是連接兩大技術的橋梁。目前對語義Web服務標記語言研究最典型的組織就是DARPA（DefenceAdvancedResearchProjectsAgency）組織，其研究組OWLServicesCoalition提出了語義Web服務標記語言OWL-S語義Web服務目前七頁\總數六十五頁\編于十五點第二節語義網目前八頁\總數六十五頁\編于十五點SemanticWeb的由來Webwas“invented”byTimBerners-Lee,aphysicistworkingatCERNTBL’soriginalvisionoftheWebwasmuchmoreambitiousthantherealityoftheexisting(syntactic)Web:TBL(andothers)havesincebeenworkingtowardsrealisingthisvision,whichhasbecomeknownastheSemanticWebE.g.,articleinMay2001issueofScientificAmerican…“...agoaloftheWebwasthat,iftheinteractionbetweenpersonandhypertextcouldbesointuitivethatthemachine-readableinformationspacegaveanaccuraterepresentationofthestateofpeople'sthoughts,interactions,andworkpatterns,thenmachineanalysiscouldbecomeaverypowerfulmanagementtool,seeingpatternsinourworkandfacilitatingourworkingtogetherthroughthetypicalproblemswhichbesetthemanagementoflargeorganizations.”目前九頁\總數六十五頁\編于十五點TheSemanticWebisanextensionofthecurrentwebinwhichinformationisgivenwell-definedmeaning,betterenablingcomputersandpeopletoworkinco-operation.

–TimBerners-Lee,JamesHendler,OraLassila,TheSemanticWeb,ScientificAmerican,May2001SemanticWeb的定義目前十頁\總數六十五頁\編于十五點SemanticWeb的架構的相關標準

本體層1.以謂詞演算為基礎的語言KIF-basedOntolingua,CycL,Loom,Frame-Logic2.基于XML的本體表示語言SHOE,XOL,OML&CKML,RDFS,Riboweb,OIL,DAML+OIL,OWL規則層RuleML、HornML、DLML邏輯框架層FOL、HOL、DL、Horn-logic、OMDoc下四層已經發展的比較成熟與完善1.數據格式層2.信息表示層3.元數據表示層4.元數據定義層5.本體層6.規則層7.邏輯框架層8.證據層9.高信度Web層Wearehere!目前十一頁\總數六十五頁\編于十五點本體(ontology)aphilosophicaldiscipline,branchofphilosophythatdealwiththenatureandtheorganizationofreality.Scienceofbeing

Triestoanswerthequestions:whatisbeing?whatarethefeaturescommontoallbeings?本體(ontology)的定義目前十二頁\總數六十五頁\編于十五點

Ontologyisaformal,explicitspecificationofasharedconceptualization–Gruber要點：Conceptualization:anabstractmodelofphenomenaintheworldbyhavingidentifiedtherelevantconceptsofthosephenomena.Explicit:thetypeofconceptsused,andtheconstraintsontheiruseareexplicitlydefined.Formal:thefactthattheontologyshouldbemachinereadable.Shared:ontologyshouldcaptureconsensualknowledgeacceptedbythecommunities

本體(ontology)的定義目前十三頁\總數六十五頁\編于十五點Whatisaconcept?

Differentcommunitieshavedifferentnotionsonwhataconceptmeans:

formalconcepts

conceptlabel

terminology

frameorOOThereism:nrelationshipbetweenwordsandconceptsdifferentwordsmayrefertothesameconceptsawordmayrefertoseveralconcepts

Ontologylanguagesshouldprovidemeansformakingthisdifferenceexplicit

本體(ontology)的定義目前十四頁\總數六十五頁\編于十五點Classesconceptsofthedomainortasks,whichareusuallyorganizedintaxonomiesinuniv-ontology:studentandprofessoraretwoclassesRelationsatypeofinteractionbetweenconceptsofthedomainsuchas:subclass-of,is-a本體的構成目前十五頁\總數六十五頁\編于十五點FunctionsAspecialcaseofrelationsinwhichthen-thelementoftherelationshipisuniqueforthen-1precedingelementsSuchas:Price-of-a-used-carcandefinethecalculationofthepriceofthesecond-handcaronthecar-model,manufacturingdataandkilometersAxioms（公理）ModelsentencesthatarealwaystrueSuchas:ifthestudentattendsbothAandBcourse,thenheorshemustbeasecondyearstudent本體的構成目前十六頁\總數六十五頁\編于十五點Instancesrepresentspecificelementssuchas:StudentcalledPeterisaninstanceofStudentclass本體的構成目前十七頁\總數六十五頁\編于十五點RDFdatamodelResourcesAresourceisathingyoutalkabout(canreference)ResourceshaveURI’s(UniformResourceIdentifiers)RDFdefinitionsarethemselvesResourcesPropertiesAspecialkindofresources,describerelationsbetweenresources.(subject,predicate,object)資源描述框架(RDF)目前十八頁\總數六十五頁\編于十五點<rdf:RDFxmlns:rdf="/1999/02/22-rdf-syntax-ns#"xmlns:uni="/2005/lesson-uni"> <rdf:Descriptionrdf:about="CIT1111"> <uni:courseName>DiscreteMathematics</uni:courseName> <uni:isTaughtBy> <rdf:Descriptionrdf:about="949318"> <uni:name>DavidBillington</uni:name> <uni:title>AssociateProfessor</uni:title> </rdf:Description> </uni:isTaughtBy> </rdf:Description></rdf:RDF>RDF目前十九頁\總數六十五頁\編于十五點Classesandproperties classes:asetofobjects,rdfs:Class instances:individualobject property:addrestrictionsonobjects,rdfs:PropertyClassandhierarchies資源描述框架模式(RDFS)目前二十頁\總數六十五頁\編于十五點

Restrictions:CoursesmusttaughtbyacademicstaffmembersonlyMichaelMaherisaprofessorifweknow,professorisasubclassofacademicstaffMichaelMaherisallowedtoteachcoursesPropertyhierarchies

資源描述框架模式(RDFS)目前二十一頁\總數六十五頁\編于十五點SomeimportantterminologiesinRDFSrdf:type類的實例和類之間的關系rdfs:subClassOf子類和類之間的關系rdfs:subPropertyOf子性質關系rdfs:domain性質的定義域rdfs:range性質的值域資源描述框架模式(RDFS)目前二十二頁\總數六十五頁\編于十五點RDF和RDFS的關系目前二十三頁\總數六十五頁\編于十五點RDF/RDFSlimitationsLocalscopeofproperties.

cowseatonlyplantsDisjointnessofclasses.MaleandfemaleBooleancombinationsofclasses.(∪,∩,～

)Cardinalityrestrictions,propertyvaluerestriction.personandparents,teacherandcoursesSpecialcharacteristicsofpropertiesSuperviseandIsSupervisedbyRDF的局限性目前二十四頁\總數六十五頁\編于十五點Requirementsforontologylanguageawell-definedsyntaxaformalsemantics(convenienttoreason)convenienceofexpressionefficientreasoningsupportsufficientexpressivepower本體描述語言OWL目前二十五頁\總數六十五頁\編于十五點OWLisbuiltontopofRDFOWLisforprocessinginformationonthewebOWLwasdesignedtobeinterpretedbycomputersOWLwasnotdesignedforbeingreadbypeopleOWLiswritteninXMLOWLisawebstandard什么是OWL目前二十六頁\總數六十五頁\編于十五點OriginsofOWLDAMLDAML+OILDAML=DARPAAgentMarkupLanguageOIL=OntologyInferenceLayerOWLisnowaW3CRecommendation!OILOWLRDFAllwereinfluencedbyRDFOWL目前二十七頁\總數六十五頁\編于十五點LogicfoundationofOWL:DescriptionLanguageOWLLite:ClassificationhierarchySimpleconstraintsOWLDL(DescriptionLogic):MaximalexpressivenessWhilemaintainingtractabilityStandardformalisationOWLFull:VeryhighexpressivenessLoosingtractabilityNon-standardformalisationAllsyntacticfreedomofRDF

(self-modifying)SyntacticlayeringSemanticlayeringFullDLLiteLayeredlanguageofOWL目前二十八頁\總數六十五頁\編于十五點OWL目前二十九頁\總數六十五頁\編于十五點OWL目前三十頁\總數六十五頁\編于十五點OWL目前三十一頁\總數六十五頁\編于十五點<?xmlversion="1.0"?><rdf:RDFxmlns:rdf="/1999/02/22-rdf-syntax-ns#"xmlns:rdfs="/2000/01/rdf-schema#"xmlns:owl="/2002/07/owl#"xmlns:dc="/dc/elements/1.1/"xml:base="http://wasp.cs.vu.nl/sekt/ontology/animal"><owl:Ontologyrdf:about=“animal"/><owl:Classrdf:ID="Eagle"><rdfs:subClassOf><owl:Classrdf:about="#Bird"/></rdfs:subClassOf></owl:Class><owl:Classrdf:ID="Animal"/><owl:Classrdf:ID="Fly"><owl:disjointWith><owl:Classrdf:about="#Penguin"/></owl:disjointWith><rdfs:subClassOfrdf:resource="#Animal"/></owl:Class><owl:Classrdf:ID="Bird"><rdfs:subClassOfrdf:resource="#Fly"/></owl:Class><owl:Classrdf:ID="Penguin"><rdfs:subClassOfrdf:resource="#Bird"/><owl:disjointWithrdf:resource="#Fly"/></owl:Class></rdf:RDF>OWLExample:animals目前三十二頁\總數六十五頁\編于十五點第三節語義Web服務目前三十三頁\總數六十五頁\編于十五點WWWURI,HTML,HTTPBringingthewebtoitsfullpotentialSemanticWebRDF,RDF(S),OWLDynamicWebServicesUDDI,WSDL,SOAPStaticSemanticWebServicesMotivationofSemanticWebService目前三十四頁\總數六十五頁\編于十五點

SemanticWebTechnology+WebServiceTechnologySemanticWebServices=SemanticWebServices

allowmachinesupporteddatainterpretationontologiesasdatamodelautomateddiscovery,selection,composition,andweb-basedexecutionofservicesasintegratedsolutionforrealizingthevisionofthenextgenerationoftheWeb.目前三十五頁\總數六十五頁\編于十五點SemanticWebServicesDefineexhaustivedescriptionframeworksfordescribingWebServicesandrelatedaspects(WebServiceDescriptionOntologies)Supportontologiesasunderlyingdatamodeltoallowmachinesupporteddatainterpretation(SemanticWebaspect)DefinesemanticallydriventechnologiesforautomationoftheWebServiceusageprocess(WebServiceaspect)

目前三十六頁\總數六十五頁\編于十五點SemanticWebServicesUsageProcess:Publication:MaketheavailabledescriptionofthecapabilityofaserviceDiscovery:LocatedifferentservicessuitableforagiventaskSelection:ChoosethemostappropriateservicesamongtheavailableonesComposition:CombineservicestoachieveagoalMediation:Solvemismatches(data,protocol,process)amongthecombinedExecution:Invokeservicesfollowingprogrammaticconventions

目前三十七頁\總數六十五頁\編于十五點SemanticWebServicesExecutionsupport:Monitoring:ControltheexecutionprocessCompensation:ProvidetransactionalsupportandundoormitigateunwantedeffectsReplacement:FacilitatethesubstitutionofservicesbyequivalentonesAuditing:Verifythatserviceexecutionoccurredintheexpectedway目前三十八頁\總數六十五頁\編于十五點SemanticWebServicesWithSemantic:Notonlyaninterfacedescription,butalsothecapabilityoftheservice.Logicreasoningenhancedservicediscoveryandcomposition.Canbedoneautomatically.目前三十九頁\總數六十五頁\編于十五點OWL-S:OntologyWebLanguageforServicesWSMLWSDL-S…語義Web服務標記語言目前四十頁\總數六十五頁\編于十五點OntologyOWL-SisanOWLontologytodescribeWebservicesOWL-SleveragesonOWLtoSupportcapabilitybaseddiscoveryofWebservicesSupportautomaticcompositionofWebServicesSupportautomaticinvocationofWebservices"Completedonotcompete"OWL-SdoesnotaimtoreplacetheWebservicesstandards ratherOWL-SattemptstoprovideasemanticlayerOWL-SreliesonWSDLforWebserviceinvocation(seeGrounding)OWL-sExpandsUDDIforWebservicediscovery(OWL-S/UDDImapping)OWL-S概述目前四十一頁\總數六十五頁\編于十五點OWL-S整體結構ResourceServiceService

ProfileService

ModelService

Groundingcommunicationprotocol(RPC,HTTP,…)portnumbermarshalling/serializationinputtypesoutputtypespreconditionseffectsprocessflowcompositionhierarchyprocessdefinitionsprovidespresents(whatitdoes)describedby

(howitworks)

supports

(howtoaccess)目前四十二頁\總數六十五頁\編于十五點服務概要ResourceServiceService

ProfileService

ModelService

Groundingprovidespresents(whatitdoes)describedby

(howitworks)

supports

(howtoaccess)目前四十三頁\總數六十五頁\編于十五點服務概要

ServiceProfilePresentedbyaservice.RepresentswhattheserviceprovidesTwomainuses:AdvertisementsofWebServicescapabilities(non-functionalproperties,QoS,Description,classification,etc.)RequestofWebserviceswithagivensetofcapabilitiesProfiledoesnotspecifyuse/invocation!目前四十四頁\總數六十五頁\編于十五點NonFunctionalPropertiesFunctionalityDescription服務概要目前四十五頁\總數六十五頁\編于十五點SummarizestheabstractcapabilityofaserviceFunctionalspecificationof

whattheserviceprovides

intermsofparameters,

subclassedas:preconditionsinputsoutputseffects服務概要—功能性描述目前四十六頁\總數六十五頁\編于十五點PreconditionsSetofconditionsthatshouldholdpriortoserviceinvocationInputsSetofnecessaryinputsthattherequestershouldprovidetoinvoketheserviceOutputsResultsthattherequestershouldexpectafterinteractionwiththeserviceprovideriscompletedEffectsSetofstatementsthatshouldholdtrueiftheserviceisinvokedsuccessfullyOftenrefertoreal-worldeffectsPackagebeingdelivered,orCreditcardbeingdebited服務概要—功能性描述：參數目前四十七頁\總數六十五頁\編于十五點ProvidessupportinginformationabouttheserviceTheseincludeserviceNametextDescriptionhas_processqualityRatingserviceParameterserviceCategorycontactInformation服務概要—非功能性描述目前四十八頁\總數六十五頁\編于十五點Sub-classingtheProfilemodelfacilitatesthecreationandspecialisationofservicecategoriesEachsubclasscan:IntroducenewpropertiesPlacerestrictionsonexistingpropertiesSub-classingcanalsobeusedtospecialiserequestsforserviceAnexampleProfileHierarchyisprovided,butotherscouldjustaseasilybedefined服務概要層次目前四十九頁\總數六十五頁\編于十五點服務概要層次：例子目前五十頁\總數六十五頁\編于十五點ResourceServiceService

ProfileService

ModelService

Groundingprovidespresents(whatitdoes)describedby

(howitworks)

supports

(howtoaccess)服務模型目前五十一頁\總數六十五頁\編于十五點ServiceProcessDescribeshowaserviceworks:internalprocessesoftheserviceSpecifiesserviceinteractionprotocolSpecifiesabstractmessages:ontologicaltypeofinformationtransmittedFacilitates(automated)Webserviceinvocationcompositioninteroperationmonitoring服務模型：描述方法目前五十二頁\總數六十五頁\編于十五點ThebasicclassoftheProcessOntologyistheProcess.Itssubclassesdescribeeachprocessby:anynumberof(possibly,conditional)inputs;anynumberof(possibly,conditional)outputs;anynumberofpreconditions,whichmustholdinorderfortheprocesstobeinvoked;anynumberof(possibly,conditional)sideeffects;anynumberofparticipants(subprocess)服務模型：過程本體目前五十三頁\總數六十五頁\編于十五點Atomicprocesses:directlyinvokable(byanagent),havenosubprocesses,executedinasinglestepCompositeprocesses:consistofother(non-compositeorcomposite)processes

TheyhaveacomposedOfproperty,bywhichthecontrolstructureoftheprocessisindicated,usingaControlConstruct

subclasses(seetable…)Simpleprocesses:abstractconcepts,usedtoprovideaviewofsomeatomicprocess,orasimplifiedrepresentationofsomecompositeprocess(i.e.,the“blackbox”viewofacollapsedcompositeprocess)服務模型：OWL-S中的過程類型目前五十四頁\總數六十五頁\編于十五點服務模型：總體結構目前五十五頁\總數六十五頁\編于十五點ConstructDescriptionSequenceExecutealistofprocessesinasequentialorderConcurrentExecuteelementsofabagofprocessesconcurrentlySplitInvokeelementsofabagofprocessesSplit+JoinInvokeelementsofabagofprocessesandsynchronizeUnorderedExecuteallprocessesinabaginanyorderChoiceChoosebetweenalternativesandexecuteoneIf-then-elseIfspecifiedconditionhold,execute“Then”,elseexecute“Else”.Repeat-UntilIterateexecutionofabagofprocessesuntilaconditionholdsRepeat-WhileIterateexecutionofabagofprocesseswhileaconditionholds服務模型：過程中的控制結構目前五十六頁\總數六十五頁\編于十五點<!–AtomicProcessDefinition-GetDesiredFlightDetails

--><rdfs:Classrdf:ID=“GetDesiredFlightDetails”> <rdfs:subClassOf

rdf:resource= “/Process#AtomicProcess”/></rdfs:Class>GetDesiredFlightDetailsAirportFlightDateAtomicProcessdepartureAirport_InoutboundDate_InAtomicProcessExample目前五十七頁\總數六十五頁\編于十五點<!–(sample)Inputsusedbyatomicprocess

GetDesiredFlightDetails--><rdf:Propertyrdf:ID="departureAirport_In">

<rdfs:subPropertyOf

rdf:resource= "http:///Process#input"/> <rdfs:domain

rdf:resource="#GetDesiredFlightDetails"/> <rdfs:range

rdf:resource=" DAML-S/concepts.daml#Airport"/></rdf:Property><rdf:Propertyrdf:ID="outbounDate_In">

<rdfs:subPropertyOf

rdf:resource="http:///Process#input"/><rdfs:domain

rdf:resource="#GetDesiredFlightDetails"/>

<rdfs:range

rdf:resource="DAML-S/concepts.daml#FlightDate"/></rdf:Property>AtomicProcessExample目前五十八頁\總數六十五頁\編于十五點<rdfs:Classrdf:ID="BookFlight"><rdfs:subClassOf

rdf:resource="#CompositeProcess"/><rdfs:subClassOf

rdf:resource="/Process#Sequence"/><daml:subClassOf><daml:Restriction><daml:onProperty

rdf:resource="/Process#components"/><daml:toClass><daml:subClassOf><daml:unionOfrdf:parseType="daml:collecti