蔡益坤臺灣大學：資訊管理學研究所黃振峰Huang, Chen-FengChen-FengHuang2007-11-262018-06-292007-11-262018-06-292005http://ntur.lib.ntu.edu.tw//handle/246246/54340Semantic Web technology facilitates automatic processing of information on the Web by making up for the inadequacy of resources that are only human-readable. It also enables service discovery when services are described with OWL, a markup language for the Web based on Description Logic. Service searches and classifications are achieved via Description Logic inference mechanisms. The expressiveness of OWL, however, is restricted due to decidability concerns. This is complemented by SWRL, a combination of subsets of OWL and RuleML, which contributes the use of Horn-like rules in conjunction with ontologies. It also provides extra inference capabilities for the ontologies. We consider a practical approach that exploits reasoning services on ontologies and rules based on current Semantic Web standards, to provide a framework for service composition. In this framework one can build ontologies and rules for the application domain, and utilizes the inference services to accomplish service composition. We also present an application for this framework and discuss some implementation issues.1 Introduction 1 1.1 Motivation and Objectives . . . . . . . . . . . . . . . . . . . . . . . . . . 2 1.2 Thesis Outline . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 2 Background 4 2.1 Web Services . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.1 WSDL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4 2.1.2 UDDI . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6 2.2 Semantic Web Technology . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.1 RDF/RDF Schema . . . . . . . . . . . . . . . . . . . . . . . . . . 8 2.2.2 OWL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 9 2.2.3 SWRL . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 12 2.3 Service Matching . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14 2.4 Service Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 2.4.1 Service Configuration in Description Logic . . . . . . . . . . . . . 15 2.4.2 OWL-S . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17 3 Preliminaries 19 3.1 Description Logics and Reasoning Services . . . . . . . . . . . . . . . . . 19 3.1.1 Description Logic Syntax and Semantics . . . . . . . . . . . . . . 20 3.1.2 Description Logic Reasoning Services . . . . . . . . . . . . . . . . 22 3.2 Reasoners for Description Logic . . . . . . . . . . . . . . . . . . . . . . . 24 3.2.1 RACER: A Semantic Web Inference Engine . . . . . . . . . . . . 25 3.2.2 Query Language . . . . . . . . . . . . . . . . . . . . . . . . . . . 27 3.3 Description Logic Programs . . . . . . . . . . . . . . . . . . . . . . . . . 27 4 A Semantic-Based Service Composition Framework 30 4.1 Service Composition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30 4.2 Framework Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 32 4.3 The Presentation Layer . . . . . . . . . . . . . . . . . . . . . . . . . . . . 33 4.4 Service Modeling in the Ontology Layer . . . . . . . . . . . . . . . . . . . 34 4.4.1 Formulating Services . . . . . . . . . . . . . . . . . . . . . . . . . 34 4.4.2 Representing Service Attributes in Ontologies . . . . . . . . . . . 36 4.5 Inference Services in the Logic Layer . . . . . . . . . . . . . . . . . . . . 37 4.5.1 The Service Matchmaker . . . . . . . . . . . . . . . . . . . . . . . 39 4.5.2 The Service Composer . . . . . . . . . . . . . . . . . . . . . . . . 40 4.6 Service Execution in the Grounding Layer . . . . . . . . . . . . . . . . . 40 5 An Application: The Trip Planner 41 5.1 Modeling a Trip Service . . . . . . . . . . . . . . . . . . . . . . . . . . . 42 5.2 Tourism Domain Ontologies . . . . . . . . . . . . . . . . . . . . . . . . . 43 5.2.1 Trip Requirements . . . . . . . . . . . . . . . . . . . . . . . . . . 44 5.2.2 Trip Advertisements . . . . . . . . . . . . . . . . . . . . . . . . . 48 5.3 Upper Ontologies . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 55 5.3.1 The Location Ontology . . . . . . . . . . . . . . . . . . . . . . . . 56 5.3.2 The ValuePartition Ontology . . . . . . . . . . . . . . . . . . . . 57 5.3.3 The Time Ontology . . . . . . . . . . . . . . . . . . . . . . . . . . 58 5.4 Applying SWRL Rules . . . . . . . . . . . . . . . . . . . . . . . . . . . . 59 5.4.1 Extending Ontologies Semantics . . . . . . . . . . . . . . . . . . . 60 5.4.2 Arranging Services in Proper Order . . . . . . . . . . . . . . . . . 62 5.4.3 Checking Consistency . . . . . . . . . . . . . . . . . . . . . . . . . 64 5.5 The Trip Planner Application . . . . . . . . . . . . . . . . . . . . . . . . 67 5.5.1 The Trip Planner Plugin . . . . . . . . . . . . . . . . . . . . . . . 68 6 Conclusion 71 6.1 Contributions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 71 6.2 Future Work . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 72940679 bytesapplication/pdfen-US描述邏輯本體論網路本體論語言法則語意網服務組裝語意網法則語言網路服務Description LogicOntologyOWLRulesSemantic WebService CompositionSWRLWeb Servicesotherhttp://ntur.lib.ntu.edu.tw/bitstream/246246/54340/1/ntu-94-R92725047-1.pdf