Role-based modeling has been investigated for over 35 years as a promising paradigm to model complex, dynamic systems. Although current software systems are characterized by increasing complexity and context-dependence, all this research had almost no influence on current software development practice, still being discussed in recent literature. One reason for this is the lack of a coherent, comprehensive, readily applicable notion of roles. Researchers focused either on relational roles or context-dependent roles rather then combining both natures. Currently, there is no role-based modeling language sufficiently incorporating both the relational and context-dependent nature of roles together with the various proposed constraints. Hence, this paper formalizes a full-fledged role-based modeling language supporting both natures. To show its sufficiency and adequacy, a real world example is employed.

Role-based modeling has been investigated for over 35 years as a promising paradigm to model complex, dynamic systems. Although current software systems are characterized by increasing complexity and context-dependence, all this research had almost no influence on current software development practice, still being discussed in recent literature. One reason for this is the lack of a coherent, comprehensive, readily applicable notion of roles. Researchers focused either on relational roles or context-dependent roles rather then combining both natures. Currently, there is no role-based modeling language sufficiently incorporating both the relational and context-dependent nature of roles together with the various proposed constraints. Hence, this paper formalizes a full-fledged role-based modeling language supporting both natures. To show its sufficiency and adequacy, a real world example is employed.

While semantic web data is machine-understandable and well suited for advanced filtering, in its raw representation it is not conveniently understandable to humans. Therefore, visualization is needed. A core challenge when visualizing the structured but heterogeneous data turned out to be a flexible mapping to Visual Variables. This work deals with a highly flexible, semi-automatic solution with a maximum support of the visualization process, reducing the mapping possibilities to a useful subset. The basis for this is knowledge, concerning metrics and structure of the data on the one hand and available visualization structures, platforms and common graphical facts on the other hand — provided by a novel basic visualization ontology. A declarative, platform-independent mapping vocabulary and a framework was developed, utilizing current standards from the semantic web and the Model-Driven Architecture (MDA). / Während Semantic-Web-Daten maschinenverstehbar und hervorragend filterbar sind, sind sie — in ihrer Rohform — nicht leicht von Menschen verstehbar. Eine Visualisierung der Daten ist deshalb notwendig. Die Kernherausforderung dabei ist eine flexible Abbildung der strukturierten aber heterogenen Daten auf Visuelle Variablen. Diese Arbeit beschreibt eine hochflexible halbautomatische Lösung bei maximaler Unterstützung des Visualisierungsprozesses, welcher die Abbildungsmöglichkeiten, aus denen der Nutzer zu wählen hat, auf eine sinnvolle Teilmenge reduziert. Die Grundlage dafür sind einerseits Metriken und das Wissen über die Struktur der Daten und andererseits das Wissen über verfügbare Visualisierungsstrukturen, -plattformen und bekannte grafische Fakten, welche durch eine neuentwickelte Visualisierungsontologie bereitgestellt werden. Basierend auf Standards des Semantic Webs und der Model-getriebenen Architektur, wurde desweiteren ein deklaratives, plattformunabhängiges Visualisierungsvokabular und -framework entwickelt.

While semantic web data is machine-understandable and well suited for advanced filtering, in its raw representation it is not conveniently understandable to humans. Therefore, visualization is needed. A core challenge when visualizing the structured but heterogeneous data turned out to be a flexible mapping to Visual Variables. This work deals with a highly flexible, semi-automatic solution with a maximum support of the visualization process, reducing the mapping possibilities to a useful subset. The basis for this is knowledge, concerning metrics and structure of the data on the one hand and available visualization structures, platforms and common graphical facts on the other hand — provided by a novel basic visualization ontology. A declarative, platform-independent mapping vocabulary and a framework was developed, utilizing current standards from the semantic web and the Model-Driven Architecture (MDA).:ABSTRACT S. x 1. INTRODUCTION S. 1 2. VISUALIZATION OF STRUCTURED DATA IN GENERAL S. 4 2.1. Global and Local Interfaces S. 4 2.2. Steps of the Visualization Process S. 4 2.3. Existing Visual Selection Mechanisms S. 6 2.4. Existing Visualizations of Structured Data S. 12 2.5. Categorizing SemVis S. 25 3. REQUIREMENTS FOR A FLEXIBLE VISUALIZATION S. 27 3.1. Actors S. 27 3.2. Use Cases S. 27 4. FRESNEL, A STANDARD DISPLAY VOCABULARY FOR RDF S. 31 4.1. Fresnel Lenses S. 31 4.2. Fresnel Formats S. 33 4.3. Fresnel Groups S. 33 4.4. Primaries (Starting Points) S. 33 4.5. Selectors and Inference S. 34 4.6. Application and Reusability S. 34 4.7. Implementation S. 35 5. A VISUALIZATION ONTOLOGY S. 37 5.1. Describing and Formalizing the Field of Visualization S. 37 5.2. Overview S. 37 5.3. VisualVariable S. 38 5.4. DiscreteVisualValue S. 39 5.5. VisualElement S. 41 5.6. VisualizationStructure S. 42 5.7. VisualizationPlatform S. 42 5.8. PresentationScenario S. 43 5.9. Facts S. 44 6. A NOVEL MAPPING VOCABULARY FOR SEMANTIC VISUALIZATION S. 45 6.1. Overview S. 45 6.2. Mapping S. 46 6.3. PropertyMapping S. 47 6.4. ImplicitMapping S. 48 6.5. ExplicitMapping S. 53 6.6. MixedMapping S. 54 6.7. ComplexMapping S. 55 6.8. Inference S. 58 6.9. Explicit Display of Relations S. 58 6.10. Limitations s. 59 7. A MODEL-DRIVEN ARCHITECTURE FOR FLEXIBLE VISUALIZATION S. 60 7.1. A Model-Driven Architecture S. 61 7.2. Applications of the MDA Pattern S. 62 7.3. Complete System Overview S. 71 7.4. Additional Knowledge of the System S. 72 7.5. Comparison to the Graphical Modelling Framework — GMF S. 77 8. VISUALIZATION PLATFORMS S. 80 8.1. Extensible 3D (X3D) S. 80 8.2. Scalable Vector Graphics (SVG) S. 81 8.3. XHTML + CSS S. 82 8.4. Text S. 82 9. OUTLOOK AND CONCLUSION S. 84 9.1. Advanced Mapping Vocabulary S. 84 9.2. Reusing Standardized Ontologies S. 84 9.3. Enabling Dynamic, Interaction and Animation S. 84 9.4. Implementation and Evaluation S. 85 9.5. Conclusion S. 85 GLOSSARY S. 86 BIBLIOGRAPHY S. 87 A. S. 90 A.1. Schemata S. 90 / Während Semantic-Web-Daten maschinenverstehbar und hervorragend filterbar sind, sind sie — in ihrer Rohform — nicht leicht von Menschen verstehbar. Eine Visualisierung der Daten ist deshalb notwendig. Die Kernherausforderung dabei ist eine flexible Abbildung der strukturierten aber heterogenen Daten auf Visuelle Variablen. Diese Arbeit beschreibt eine hochflexible halbautomatische Lösung bei maximaler Unterstützung des Visualisierungsprozesses, welcher die Abbildungsmöglichkeiten, aus denen der Nutzer zu wählen hat, auf eine sinnvolle Teilmenge reduziert. Die Grundlage dafür sind einerseits Metriken und das Wissen über die Struktur der Daten und andererseits das Wissen über verfügbare Visualisierungsstrukturen, -plattformen und bekannte grafische Fakten, welche durch eine neuentwickelte Visualisierungsontologie bereitgestellt werden. Basierend auf Standards des Semantic Webs und der Model-getriebenen Architektur, wurde desweiteren ein deklaratives, plattformunabhängiges Visualisierungsvokabular und -framework entwickelt.:ABSTRACT S. x 1. INTRODUCTION S. 1 2. VISUALIZATION OF STRUCTURED DATA IN GENERAL S. 4 2.1. Global and Local Interfaces S. 4 2.2. Steps of the Visualization Process S. 4 2.3. Existing Visual Selection Mechanisms S. 6 2.4. Existing Visualizations of Structured Data S. 12 2.5. Categorizing SemVis S. 25 3. REQUIREMENTS FOR A FLEXIBLE VISUALIZATION S. 27 3.1. Actors S. 27 3.2. Use Cases S. 27 4. FRESNEL, A STANDARD DISPLAY VOCABULARY FOR RDF S. 31 4.1. Fresnel Lenses S. 31 4.2. Fresnel Formats S. 33 4.3. Fresnel Groups S. 33 4.4. Primaries (Starting Points) S. 33 4.5. Selectors and Inference S. 34 4.6. Application and Reusability S. 34 4.7. Implementation S. 35 5. A VISUALIZATION ONTOLOGY S. 37 5.1. Describing and Formalizing the Field of Visualization S. 37 5.2. Overview S. 37 5.3. VisualVariable S. 38 5.4. DiscreteVisualValue S. 39 5.5. VisualElement S. 41 5.6. VisualizationStructure S. 42 5.7. VisualizationPlatform S. 42 5.8. PresentationScenario S. 43 5.9. Facts S. 44 6. A NOVEL MAPPING VOCABULARY FOR SEMANTIC VISUALIZATION S. 45 6.1. Overview S. 45 6.2. Mapping S. 46 6.3. PropertyMapping S. 47 6.4. ImplicitMapping S. 48 6.5. ExplicitMapping S. 53 6.6. MixedMapping S. 54 6.7. ComplexMapping S. 55 6.8. Inference S. 58 6.9. Explicit Display of Relations S. 58 6.10. Limitations s. 59 7. A MODEL-DRIVEN ARCHITECTURE FOR FLEXIBLE VISUALIZATION S. 60 7.1. A Model-Driven Architecture S. 61 7.2. Applications of the MDA Pattern S. 62 7.3. Complete System Overview S. 71 7.4. Additional Knowledge of the System S. 72 7.5. Comparison to the Graphical Modelling Framework — GMF S. 77 8. VISUALIZATION PLATFORMS S. 80 8.1. Extensible 3D (X3D) S. 80 8.2. Scalable Vector Graphics (SVG) S. 81 8.3. XHTML + CSS S. 82 8.4. Text S. 82 9. OUTLOOK AND CONCLUSION S. 84 9.1. Advanced Mapping Vocabulary S. 84 9.2. Reusing Standardized Ontologies S. 84 9.3. Enabling Dynamic, Interaction and Animation S. 84 9.4. Implementation and Evaluation S. 85 9.5. Conclusion S. 85 GLOSSARY S. 86 BIBLIOGRAPHY S. 87 A. S. 90 A.1. Schemata S. 90