Guido Vetere

Models for semantic interoperability in service-oriented architectures

Although service-oriented architectures go a long way toward providing interoperability in distributed, heterogeneous environments, managing semantic differences in such environments remains a challenge. We give an overview of the issue of semantic interoperability (integration), provide a semantic characterization of services, and discuss the role of ontologies. Then we analyze four basic models of semantic interoperability that differ in respect to their mapping between service descriptions and ontologies and in respect to where the evaluation of the integration logic is performed. We also provide some guidelines for selecting one of the possible interoperability models.

Hyper: A Framework for Peer-to-Peer Data Integration on Grids

Data Grids allow for seeing heterogeneous, distributed, and dynamic informational resources as if they were a uniform, stable, secure, and reliable database. According to this view, current proposals for data integration on Grids are based on the notion of global schema built over a collection of autonomous information sources. On the other hand, in dynamic and distributed environments, such a hierarchical and centralized architecture is not well suited for effective information integration. Peer-to-peer data integration aims at overcoming these drawbacks by modeling autonomous information systems as peers, and establishing mappings among peers without resorting to any hierarchical structure. In this paper, we present Hyper, a joint research initiative of Universita di Roma “La Sapienza” and IBM Italia, which aims at developing principles and techniques for peer-to-peer data integration on a Grid infrastructure. The main contributions presented are a semantic characterization of P2P data integration, the deployment of our P2P framework on a Grid architecture, and the design of a query answering algorithm that is coherent both with the semantics and with the Grid infrastructure.

Senso Comune: A Collaborative Knowledge Resource for Italian

Senso Comune is an open knowledge base for the Italian language, available through a Web-based collaborative platform, whose construction is in progress. The resource integrates dictionary data coming from both users and legacy resources with an ontological backbone, which provides foundations for a formal characterization of lexical semantic structures (frames). A nucleus of basic Italian lemmas, which have been semantically analyzed and classified, is available for both online access and download. A restricted community of contributors is currently working on increasing the lexical coverage of the resource.

Exploiting Linked Data and Knowledge Graphs in Large Organisations

This book addresses the topic of exploiting enterprise-linked data with a particularfocus on knowledge construction and accessibility within enterprises. It identifies thegaps between the requirements of enterprise knowledge consumption and standarddata consuming technologies by analysing real-world use cases, and proposes theenterprise knowledge graph to fill such gaps. It provides concrete guidelines for effectively deploying linked-data graphs withinand across business organizations. It is divided into three parts, focusing on the keytechnologies for constructing, understanding and employing knowledge graphs. Part 1 introduces basic background information and technologies, and presents asimple architecture to elucidate the main phases and tasks required during the lifecycleof knowledge graphs. Part 2 focuses on technical aspects; it starts with state-of-theart knowledge-graph construction approaches, and then discusses exploration andexploitation techniques as well as advanced question-answering topics concerningknowledge graphs. Lastly, Part 3 demonstrates examples of successful knowledgegraph applications in the media industry, healthcare and cultural heritage, and offersconclusions and future visions.

Accessing data through ontologies with ONDA

Accessing distributed and heterogeneous data sources through domain-oriented conceptual models (ontologies) facilitates the development of smarter information systems, as per the Semantic Web vision. To apply this vision to industrial grade applications, concept-based query answering must be efficient and scalable. This paper describes ONDA, a technology developed at the IBM Center for Advanced Studies of Rome which enables intelligent access to legacy relational information systems by means of ontologies. With ONDA, users can map rich conceptual models to existing or new relational data sources, and can query actual data through business concepts instead of the specific schemas of the data sources. By adopting a language of limited expressiveness ONDA ensures sound and complete query answering to conjunctive queries with the same efficiency and scalability of the underlying relational sources. This paper illustrates ONDAs basic principles, outlines the system architecture and implementation, and presents prototypical applications. Finally, further research and development plans are discussed.

An open knowledge base for Italian language in a collaborative perspective

In this paper, we describe the architecture and collaborative approach adopted for the development of Senso Comune (SC), an open knowledge base for the Italian language that combines lexicographic, linguistic, ontological and textual data in a web-based collaborative platform. Senso Comune aims at integrating lexicographic data from users and legacy resources with a formally characterized ontology grounded on lexical semantic structures. Senso Comune was conceived as a linguistic knowledge base rather than a dictionary. It is actually based on a conceptual apparatus that is unusual in typical linguistic resources:, each sense is mapped to ontological categories, and is associated with semantic frames. A wiki provides a collaborative platform for editing a basic lexicon of Italian with different access and annotation privileges that dynamically enables crowd-sourced annotations. Senso Comune proposes different levels of interrelated representation layers that differently exploit collaborative annotation.

Semantic Integration of Peer to Peer Systems: A Doxastic Approach

Peer to peer information integration takes place when, within internetworking systems, a dependency between provided and consumed information is maintained. At large, the semantic Web could be seen as a semantically integrated peer to peer system. These systems have been thoroughly studied by means of multi-agent epistemic logic frameworks. Most of the proposed approaches, however, in seek of generality, fail to provide means to implement the vast array of integration strategies that peers could adopt. We propose here a formal framework to overcome these limitations. Our approach resorts on a logic that prevents peer to peer mappings from causing direct knowledge transfers, and introduces a class of specific knowledge construction axioms to model concrete integration in a flexible way.

Question Answering and Knowledge Graphs

In the Digital and Information Age, companies and government agencies are highly digitalized, as the information exchanges happening in their processes. They store information both as natural language text and structured data, e.g., relational databases or knowledge graphs. In this scenario, methods for organizing, finding, and selecting relevant information, beyond the capabilities of classic Information Retrieval, are always active topics of research and development.

Enterprise Knowledge Graph: Looking into the Future

Congratulations! We have covered architecture, technical details, and success stories of the knowledge graph for Large Organizations together, in the eight chapters that we have just walked over.

Enterprise Knowledge Graph: An Introduction

Compared to other knowledge-oriented information systems, the distinctive features of Knowledge Graphs lie in their special combination of knowledge representation structures, information management processes, and search algorithms.