Semantic Approaches for Accessing Distributed Information

1Introduction This chapter is devoted to introduce the motivations and general characteris- tics of our approaches for accessing distributed information. The plan of the chapter is as follows: in the first section we illustrate the motivations which led to the definition of the proposed approach; the second section aims at illus- trating the general characteristics of the proposed methodologies. related works are presented in the third section, whereas contributions of our approaches, as well as its novelties w.r.t. already known methodologies, are described in the fourth section. Finally, the last section provides an overview of the thesis or- ganization. 1.1 Motivations The confluence of ever smaller and more powerful computing and communi- cation devices, along with improved connectivity in both wired and wireless environments, is leading to a world in which computers are playing an ever increasing role in peoples daily lives. An immediate consequence of this trend is the increasing availability of large amount of information and services in electronic format [143]. Due to this reason, a user can access information distributed across disparate data sources and connected through a suitable network infrastructure; in addition, he can profit by services supplied by public and private organizations: as an example, a large number of banks provide mobile banking services allowing a user to access his bank account (e.g., he can check his balance, stop a cheque payment, and so on) and conduct real-time banking transactions by his own mobile device [174]; as a further example, government agencies are showing a growing interest to deliver a large number of services through the Internet; for instance, a research reported in [224] foresees that, in the United States, by 2006, the government fees and taxes collected online will be about 602 billions of US dollars, i.e., about the 15% of total US government fund collection.