The original and still a major purpose of ontologies in computer and information sciences is to serve for the semantic integration of represented content, facilitating information system interoperability. Content can be data, information, and knowledge, and it can be distributed within or across these categories. A myriad of languages is available for representation. Ontologies themselves are artifacts which are expressed in various languages. Different such languages are utilized today, including, as well-known representatives, predicate logic, subsuming first-order (predicate) logic (FOL), in particular, and higher-order (predicate) logic (HOL); the Web Ontology Language (OWL) on the basis of description logics (DL); and the Unified Modeling Language (UML). We focus primarily on languages with formally defined syntax and semantics. This overall picture immediately suggests questions of the following kinds: What is the relationship between an ontology and the language in which it is formalized? Especially, what is the impact of the formal semantics of the language on the formalized ontology? How well understood is the role of ontologies in semantic integration? Can the same ontology be represented in multiple languages and/or in distinct ways within one language? Is there an adequate understanding of whether two expressions are intensionally/conceptually equivalent and whether two ontologies furnish the same ontological commitments? One may assume that these questions are resolved. Indeed, the development and adoption of ontologies is widespread today. Ontologies are authored in a broad range of different languages, including offering equally named ontologies in distinct languages. Much research is devoted to techniques and technologies that orbit ontologies, for example, ontology matching, modularization, learning, and evolution, to name a few. Ontologies have found numerous beneficial applications, and hundreds of ontologies have been created, considering solely the context of biomedical research. For us, these observations increase the relevance of the stated questions and close relatives thereof, and raise the desire for solid theoretical underpinnings. In the literature of computer and information sciences, we have found only few approaches that tackle the foundations of ontologies and their representation to allow for answering such questions or that actually answer them. We elaborate an analysis of the subject as the first item of central contributions within this thesis. It mainly results in the identification of a vicious circularity in (i) the intended use of ontologies to mediate between formal representations and (ii) solely exploiting formal semantic notions in representing ontologies and defining ontology-based equivalence as a form of intensional/conceptual equivalence. On this basis and in order to overcome its identified limitations, we contribute a general model-theoretic semantic account, named \\\"ontological semantics\\\". This kind of semantics takes the approach of assigning arbitrary entities as referents of atomic symbols and to link syntactic constructions with corresponding ontological claims and commitments. In particular, ontological semantics targets the avoidance of encoding effects in its definition. Therefore we argue that this semantic account is well suited for interpreting formalized ontologies and for defining languages for the representation of ontologies. It is further proposed as a fundament for envisioned novel definitions of the intensional equivalence of expressions, in potential deviation from only being formally equivalent under set-theoretic semantics. The thesis is defended that a particular usage of a formalism and its respective vocabulary should be accompanied by establishing an ontological semantics that is tailored to that use of the formalism, in parallel to the formal semantics of the language, in order to capture the ontological content of the formal representation for adequate reuse in other formalisms. Accordingly, we advocate ontological semantics as a useful framework for justifying translations on an intensional basis. Despite all deviations of ontological semantics from its set-theoretic blueprint, close relationships between the two can be shown, which allow for using established FOL and DL reasoners while assuming ontological semantics.

L’analyse spatiale de données géographies connaît un regain d’intérêt dans la communauté des bases de données relationnelles. Plus spécifiquement, les opérations et les fonctions spatiales utilisées comme base de l’analyse spatiale sont implémentées par les grands noms des systèmes de gestion de bases de données relationnelles limitant ainsi l’hétérogénéité structurelle des systèmes. En outre, la littérature est abondante en publications dans le domaine des ontologies spatiales afin de limiter l’hétérogénéité sémantique des sources de données tout en améliorant l’interopérabilité de ces données. Bien que l’interopérabilité des données soit l’un des objectifs du Web Sémantique, tout le potentiel de ces outils et de ces techniques basés sur la connaissance n’a pas été révélé. Avec l’influence sans cesse croissante du Web Sémantique à travers ces outils et applications en gestion de la connaissance et système intelligent, les applications utilisant des données géospatiales suivent ce phénomène en bénéficiant de son influence. Cette thèse se focalise sur l’utilisation de la connaissance métier afin de gérer des données spatiales à l’aide des technologies du Web sémantique. L’activité de recherche menée dans le cadre de cette thèse est réalisée sur des données provenant du domaine de l’archéologie industrielle. Cet environnement se caractérise par son hétérogénéité et sa grande quantité de données offrant ainsi un cadre idéal pour la réalisation d’un outil de gestion de connaissance. Cet outil basé sur les technologies du Web Sémantique a été prototypé sous le nom d’ArchaeoKM suivant le principe des 4 K, Knowledge Acquisition, Knowledge Management, Knowledge Visualization and Knowledge Analysis. Ce même principe est mis en œuvre pour les données spatiales. Une ontologie de haut niveau a été développée pour servir de cadre applicatif à la gestion des données spatiales permettant d’ajuster une ontologie de domaines sans composante spatiale. Le processus de gestion de la connaissance commence avec l’acquisition de la signature spatiale des objets identifiés. Cette signature est stockée dans un système de gestion de bases de données spatiales et est référencée par l’objet correspondant dans la base de connaissance. La connaissance spatiale de ces objets est générée à l’aide des fonctions et des opérations spatiales au niveau de la base de données spatiale et l’enrichissement de la base de connaissance est réalisé avec le résultat de ces opérations et fonctions. L’inférence de nouvelle connaissance sur la base des données existante est réalisée à l’aide de SWRL (Semantic Web Rule Language). De plus, ce langage a été étendu à l’aide de nouveaux built-ins spatiaux afin de prendre en sidération la dimension spatiale des données. De même, cette dimension spatiale a été apportée au langage SPARQL afin de réaliser des requêtes spatiales sur la base de connaissances.En effet, l’objectif principal de cette thèse est d’initier le premier pas vers l’intégration des composantes spatiales avec les technologies du Web Sémantique. Le processus d’intégration est premier plan pour les deux technologies. D’un point de vue Web Sémantique, l’intégration de données non communes dans ce cadre applicatif ouvre la porte à l’intégration de données beaucoup plus large. D’un point de vue des systèmes d’information géographique, l’inclusion de la connaissance permet une gestion métier des données rendant l’analyse plus proche de l’interprétation humaine. / Spatial technology has gained momentum under database systems. More specifically, the spatial operations and spatial functions are used to carry out spatial analysis which can be executed through these database systems. In addition, there has been significant amount of research in the field of the geospatial ontology domain in order to achieve the semantic interoperability between different data sources. Although, data interoperability is one of the main objectives of the Semantic Web technologies, the potentiality of the underlying knowledge tools and techniques have not been completely identified. With the growing influence of the Semantic Web technologies towards the application based on knowledge management and intelligent systems, the geospatial application benefits from this influence. This thesis emphasizes on the use of knowledge to manage spatial data within spatial information systems through the Semantic Web framework. This research activity is carried out with the backdrop of the case study of the industrial archaeology. It sets up an ideal environment for the application of knowledge to manage the huge and heterogeneous dataset. The use of knowledge to manage the diversity of information was well executed through the application prototype named ArchaeoKM which is based on the Semantic Web. The ArchaeoKM framework follows the 4Ks processing steps: Knowledge Acquisition, Knowledge Management, Knowledge Visualization and Knowledge Analysis. The same processing principle of 4Ks was implemented during the spatial knowledge processing. A top level ontology was developed in order to serve as the background representation of the case study in order to adjust the spatial components. Keeping the custom, the spatial knowledge processing begins with acquiring spatial signatures of the identified objects. The spatial signatures are stored within the spatial database system with proper mapping to the objects in the knowledge base. The spatial knowledge of these objects is managed through executing the spatial functions at the database level and enriching the knowledge base with the results. This spatially enriched knowledge base is used again to analyze the spatial knowledge. This research thesis benefits from Semantic Web Rule Language in order to infer knowledge. In addition, the spatial built-ins proposed during the course add up spatial dimension to the SWRL for spatial inferences. Similarly, a spatial extension of the query language SPARQL is proposed in order to query spatial knowledge from the knowledge base. Actually, this research thesis provides the initial steps in integrating spatial components within the Semantic Web framework. This integration process is important for both technologies. Regarding the Semantic Web, the integration of non-typical semantic information within this framework opens up doors to other data pattern making the transformation of technologies easier. Likewise, geospatial technologies and GIS systems benefits through the inclusion of knowledge in the analysis process making the analysis much closer and efficient to human interpretation.

The original and still a major purpose of ontologies in computer and information sciences is to serve for the semantic integration of represented content, facilitating information system interoperability. Content can be data, information, and knowledge, and it can be distributed within or across these categories. A myriad of languages is available for representation. Ontologies themselves are artifacts which are expressed in various languages. Different such languages are utilized today, including, as well-known representatives, predicate logic, subsuming first-order (predicate) logic (FOL), in particular, and higher-order (predicate) logic (HOL); the Web Ontology Language (OWL) on the basis of description logics (DL); and the Unified Modeling Language (UML). We focus primarily on languages with formally defined syntax and semantics. This overall picture immediately suggests questions of the following kinds: What is the relationship between an ontology and the language in which it is formalized? Especially, what is the impact of the formal semantics of the language on the formalized ontology? How well understood is the role of ontologies in semantic integration? Can the same ontology be represented in multiple languages and/or in distinct ways within one language? Is there an adequate understanding of whether two expressions are intensionally/conceptually equivalent and whether two ontologies furnish the same ontological commitments? One may assume that these questions are resolved. Indeed, the development and adoption of ontologies is widespread today. Ontologies are authored in a broad range of different languages, including offering equally named ontologies in distinct languages. Much research is devoted to techniques and technologies that orbit ontologies, for example, ontology matching, modularization, learning, and evolution, to name a few. Ontologies have found numerous beneficial applications, and hundreds of ontologies have been created, considering solely the context of biomedical research. For us, these observations increase the relevance of the stated questions and close relatives thereof, and raise the desire for solid theoretical underpinnings. In the literature of computer and information sciences, we have found only few approaches that tackle the foundations of ontologies and their representation to allow for answering such questions or that actually answer them. We elaborate an analysis of the subject as the first item of central contributions within this thesis. It mainly results in the identification of a vicious circularity in (i) the intended use of ontologies to mediate between formal representations and (ii) solely exploiting formal semantic notions in representing ontologies and defining ontology-based equivalence as a form of intensional/conceptual equivalence. On this basis and in order to overcome its identified limitations, we contribute a general model-theoretic semantic account, named \\\"ontological semantics\\\". This kind of semantics takes the approach of assigning arbitrary entities as referents of atomic symbols and to link syntactic constructions with corresponding ontological claims and commitments. In particular, ontological semantics targets the avoidance of encoding effects in its definition. Therefore we argue that this semantic account is well suited for interpreting formalized ontologies and for defining languages for the representation of ontologies. It is further proposed as a fundament for envisioned novel definitions of the intensional equivalence of expressions, in potential deviation from only being formally equivalent under set-theoretic semantics. The thesis is defended that a particular usage of a formalism and its respective vocabulary should be accompanied by establishing an ontological semantics that is tailored to that use of the formalism, in parallel to the formal semantics of the language, in order to capture the ontological content of the formal representation for adequate reuse in other formalisms. Accordingly, we advocate ontological semantics as a useful framework for justifying translations on an intensional basis. Despite all deviations of ontological semantics from its set-theoretic blueprint, close relationships between the two can be shown, which allow for using established FOL and DL reasoners while assuming ontological semantics.:* Preface ** Abstract ** Contents ** Acknowledgments ** Foreword 1 Introduction 1.1 Background 1.2 Motivations 1.3 Theses, Objectives and Scope 1.4 Outline and Contributions 1.5 Formal Preliminaries 2 Foundations on Languages, Semantics, and Ontology 2.1 Formal Syntax and Formal Semantics 2.2 The Role of Ontologies in Semantic Integration 2.3 Ontological Analysis and Meta-Ontological Architecture 2.4 Conceptualization of Categories and Relations - CR 2.5 Summary of the Analysis and Next Steps 3 Views on Set-Theoretic Semantics of Classical Predicate Logics 3.1 Tarskian Model Theory and Set-Theoretic Superstructure 3.2 Formal Semantics and Choices for Entity Postulation 3.3 Theory View of Semantics 3.4 Aims for an Ontologically Neutral Semantic Account 4 Ontological Semantics 4.1 Definition of Ontological Structures by Analogy to the Set-Theoretic Approach 4.2 Properties and Further Background for Ontological Structures in General 4.3 Ontological Models & Signature Aspects 4.4 Semantics of Predication 4.5 Semantics of Connectives and Quantifiers & Semantic Notions 4.6 Relations between Ontological and Set-Theoretic Semantics 4.7 Ontological Neutrality 5 Ontological Engineering and Applications 5.1 Formalization Method for Ontology Representation in FOL 5.2 Ontological Usage Schemes 5.3 Glimpse on Characterizing Modular Representation 5.4 Applications in the Biomedical Domain 6 Contributions to Ontologies 6.1 Formalizations of Categories and Relations - CR 6.2 Remarks on Further Contributions 6.3 Ontologies of Time 7 Conclusion and Continuation 7.1 Resume 7.2 Related Work 7.3 Conclusions 7.4 Beginnings of Future Work Appendix A Additional Preliminaries A.1 Logical Notions A.2 Axiomatic Systems of Set and Number Theory B Axioms of the CR Taxonomy in OWL B.1 Asserted OWL Class Axioms B.2 Asserted OWL Object Property Axioms C Lists of Figures and Tables C.1 List of Figures C.2 List of Tables D Abbreviations, Acronyms and Names D.1 Abbreviations D.2 Acronyms and Names E References E.1 Literature References E.2 Web References/List of URLs F Work and Author Information ** Selbständigkeitserklärung (Declaration of Authorship) ** Bibliographic Data ** Scientific Record