Ontology Based Query Processing For Global Information Systems

This work is a revision of the doctoral dissertation of Eduardo Mena pre sented to the Department of Computer Science and System Engineering at the University of Zaragoza (Spain) in November 1998 [Mena 98]. The OBSERVER system was developed as a result of this Ph.D. thesis. This book is composed of eight chapters. In Chapter 1 we introduce our rationale for writing a book about systems that process queries in global information systems. Then in Chapter 2 we review the techno logical context for our work, including distributed and heterogeneous environments and the use of ontologies. We also compare related work to our own. Chapter 3 presents our proposed global system architecture for query processing in global information systems. The main modules in the architecture and the main steps given to process a query are briefly introduced. Chapters 4 through 7 provide a detailed description of each query processing step. In Chapter 4 we detail the steps needed to access the data corre sponding to a query formulated over an ontology. All the aspects related to distribution, structural and semantic heterogeneity, and restricted query capabilities of the underlying data repositories are considered in this chapter. The main features of the mapping information that relates ontologies and data repositories are also described. Finally, we show the process of generating appropriate plans to access each involved reposi tory and the correlation of the answers coming from different reposito ries.

This book constitutes the refereed post-proceedings of the First and Second VLDB Workshop Ontologies-based techniques for DataBases and Information Systems, held in Trondheim, Norway, September 2005 and Seoul, Korea, September 2006. The topics include ontology-based interoperability and schema matching, management of ontological bases and links between ontologies and knowledge.

We can now say that it is really a big pleasure for us to welcome all of you to the proceedings of CAiSE 2005 which was held in Porto.

These arethe proceedingsof the Fourth InternationalWorkshopon Cooperative Information Agents, held in Boston Massachusetts, USA, July 7-9, 2000. Cooperative information agent research and development focused originally onaccessingmultiple,heterogeneous,anddistributedinformationsources. Ga- ingaccesstothesesystems,throughInternetsearchengines,applicationprogram interfaces, wrappers, and web-based screens has been an important focus of - operative intelligent agents. Research has also focused on the integration of this information into a coherent model that combined data and knowledge from the multiple sources. Finally, this information is disseminated to a wide audience, giving rise to issues such as data quality, information pedigree, source reliability, information security, personal privacy, and information value. Research in - operative information agents has expanded to include agent negotiation, agent communities, agent mobility, as well as agent collaboration for information d- covery in constrained environments. TheinterdisciplinaryCIAworkshopseriesencompassesa widevarietyoft- ics dealing with cooperative information agents. All workshop proceedings have been published by Springer as Lecture Notes in Arti?cial Intelligence, Volumes 1202 (1997), 1435 (1998), and 1652 (1999), respectively. This year, the theme of the CIA workshop was ”’The Future of Information Agents in Cyberspace”, a very ?tting topic as the use of agents for information gathering, negotiation, correlation, fusion, and dissemination becomes ever more prevalent. We noted a marked trend in CIA 2000 towards addressing issues related to communities of agents that: (1) negotiate for information resources, (2) build robust ontologies to enhance search capabilities, (3) communicate for planning and problem so- ing, (4) learn and evolve based on their experiences, and (5) assume increasing degrees of autonomy in the control of complex systems.

Ontological Engineering refers to the set of activities that concern the ontology development process, the ontology life cycle, the methods and methodologies for building ontologies, and the tool suites and languages that support them. During the last decade, increasing attention has been focused on ontologies and Ontological Engineering. Ontologies are now widely used in Knowledge Engineering, Artificial Intelligence and Computer Science; in applications related to knowledge management, natural language processing, e-commerce, intelligent integration information, information retrieval, integration of databases, b- informatics, and education; and in new emerging fields like the Semantic Web. Primary goals of this book are to acquaint students, researchers and developers of information systems with the basic concepts and major issues of Ontological Engineering, as well as to make ontologies more understandable to those computer science engineers that integrate ontologies into their information systems. We have paid special attention to the influence that ontologies have on the Semantic Web. Pointers to the Semantic Web appear in all the chapters, but specially in the chapter on ontology languages and tools.

This book constitutes the refereed joint proceedings of six internationl workshops held in conjunction with the 23rd International Conference on Conceptual Modeling, ER 2004, in Shanghai, China in November 2004. The 56 revised full papers presented were carefully reviewed and selected from 163 submissions. The papers are organized in topical sections on geographical conceptual modeling; spatial storage, indexing, and data consistency; spatial representation and spatial services; spatial queries and retrieval, Web information integration; Web information mining; conceptual models for Web information; Web information systems and Webservices; systems evolution support in conceptual modeling; temporal and evolution aspects in Internat-based information systems; schema evolution and versioning in data management; conceptual modeling of agents; agents applications; digital government systems; digital government technologies; e-business systems requirements engineering; and e-business processes and infrastructure.

Details recent research in areas such as ontology design for information integration, metadata generation and management, and representation and management of distributed ontologies. Provides decision support on the use of novel technologies, information about potential problems, and guidelines for the successful application of existing technologies.

These are the proceedings of the 7th International Workshop on Cooperative Information Agents (CIA 2003), held at the Sonera Conference Center in H- sinki, Finland, August 27–29, 2003. It was co-located with the 4th Agentcities Information Days. One key challenge of developing advanced agent-based information systems is to balance the autonomy of networked data and knowledge sources with the pot- tial payo? of leveraging them by the appropriate use of intelligent information agents on the Internet. An information agent is a computational software entity thathasaccesstooneormultiple,heterogeneous,anddistributeddataandinf- mation sources; proactively searches for and maintains relevant information on behalfofitshumanusersorotheragents,preferablyjust-in-time. Inotherwords, it is managing and overcoming the di?culties associated with information ov- load in the open and exponentially growing Internet and Web. Depending on the application and tasks at hand information agents may collaborate in open, n- worked data and information environments to provide added value to a variety of applications in di?erent domains. Thus, research and development of inf- mation agents is inherently interdisciplinary: It requires expertise in information retrieval, arti?cial intelligence, database systems, human-computer interaction, and Internet and Web technology. Initiated in 1997, the purpose of the annual international workshop series on cooperativeinformationagents(CIA)istoprovideaninterdisciplinaryforumfor researchers, software developers, and managers to get informed about, present, anddiscussthelatesthigh-qualityresultsinadvancementsoftheoryandpractice in information agent technology for the Internet and Web. Each event of this renowned series attempts to capture the intrinsic interdisciplinary nature of this research area by calling for contributions from di?erent research communities, and by promoting open and informative discussions on all related topics.