Universiẗat, Diss., 2003--Würzburg.

Linklets are location-independent web services, which consume and produce Linked Data resources. These resources form a web of data - the semantic web - that is an abstraction of the web 2.0. However, enterprises are reluctant to provide valuable Linked Data resources due to missing financial stimuli. Operations are not representable in the semantic web. Linklets aim to solve both problems. Previous work developed a prototype. The goal of this thesis is to enhance it by a component model, a formal description and a permission model. A business model has to be developed. This thesis follows a bottom-up approach. The formalization of the Linklet concept creates a foundation. Then, an improved architecture and its reference implementation are studied. It is evaluated by tests, show cases and economic considerations. The resulting component system is based on web-service component systems, while a sandbox concept is the core of the permission model. The formal description shows limits of OWLs open world assumption. A platform leader strategy is the foundation for the business model. In conclusion, the advantages of the Linklet concept provide a way to enhance and monetize the value of the semantic web. Further research is required; the practical use has to be considered.

Linklets are location-independent web services, which consume and produce Linked Data resources. These resources form a web of data - the semantic web - that is an abstraction of the web 2.0. However, enterprises are reluctant to provide valuable Linked Data resources due to missing financial stimuli. Operations are not representable in the semantic web. Linklets aim to solve both problems. Previous work developed a prototype. The goal of this thesis is to enhance it by a component model, a formal description and a permission model. A business model has to be developed. This thesis follows a bottom-up approach. The formalization of the Linklet concept creates a foundation. Then, an improved architecture and its reference implementation are studied. It is evaluated by tests, show cases and economic considerations. The resulting component system is based on web-service component systems, while a sandbox concept is the core of the permission model. The formal description shows limits of OWLs open world assumption. A platform leader strategy is the foundation for the business model. In conclusion, the advantages of the Linklet concept provide a way to enhance and monetize the value of the semantic web. Further research is required; the practical use has to be considered.:1 Introduction 1.1 Motivation 1.2 Thesis 1.3 Contributions of This Work 1.4 Overview 2 Background 2.1 Preliminaries 2.1.1 Linked Data 2.1.2 Composition Models 2.1.3 Java 2 Security Permission Model 2.1.4 OSGi 2.1.5 Related Work 2.2 Formalization of Linklets 2.2.1 Definition 2.2.2 Analogy to Pipes and Filters 2.2.3 Analogy to Database Operators 2.2.4 Related Work 3 Enhancement of the Linklet Architecture 3.1 Linklet Composition 3.1.1 Requirements 3.1.2 Existing Approaches 3.1.3 Possible Approaches 3.1.4 Architecture 3.1.5 Outlook 3.2 Formal Description 3.2.1 Requirements 3.2.2 Mathematical Formalization 3.2.3 Existing Approaches 3.2.4 Architecture 3.2.5 Outlook 3.3 Permission Model 3.3.1 Requirements 3.3.2 Related Work 3.3.3 Permission Model 3.3.4 Security Architecture 3.3.5 Outlook 4 Implementation and Test 4.1 Implementation 4.1.1 Design Decisions 4.1.2 Static View 4.1.3 Dynamic View 4.2 Test 4.2.1 Test Plan 4.2.2 Test Design Specification 4.2.3 Test Realization 4.2.4 Test Results 5 Application Areas for Linklets 5.1 Business Model 5.1.1 Product Innovation 5.1.2 Infrastructure Management 5.1.3 Customer Interface 5.1.4 Financial Aspects 5.1.5 Conclusion 5.2 Show Cases for Linklets 5.2.1 Restaurant Scenario 5.2.2 Annotation Scenario 5.2.3 eBay Scenario 6 Discussion 6.1 Results 6.2 Evaluation 6.3 Future Work 6.4 Conclusion A Ontology B First Steps With Linklets B.1 Development of the Linklet Artifact B.1.1 Adoption of the LinkletActivator Class B.1.2 Development of the Linklet Class B.2 Start of the Linklet