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Research has deeply investigated several issues related to the use of integrity constraints on relational databases. In particular, a great deal of attention has been devoted to the problem of extracting "reliable" information from databases containing pieces of information inconsistent with regard to some integrity constraints. In this manuscript, the problem of extracting consistent information from relational databases violating integrity constraints on numerical data is addressed. Aggregate constraints defined as linear inequalities on aggregate-sum queries on input data are considered. The notion of repair as consistent set of updates at attribute-value level is exploited, and the characterization of several data-complexity issues related to repairing data and computing consistent query answers is provided. Moreover, a method for computing "reasonable" repairs of inconsistent numerical databases is introduced, for a restricted but expressive class of aggregate constraints. An extension of this method for dealing with the data repairing problem in the presence of weak aggregate constraints which are expected to be satisfied, but not required to, is presented. Furthermore, a technique for computing consistent answers of aggregate queries in the presence of a wide form of aggregate constraints is provided. Finally, extensions of the framework as well as several open problems are discussed. |
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 Artificial General Intelligence (Cognitive Technologies)This is the first book on current research on artificial general intelligence (AGI), work explicitly focused on engineering general intelligence – autonomous, self-reflective, self-improving, commonsensical intelligence. Each author explains a specific aspect of AGI in detail in each chapter, while also investigating the common themes in... | | Java 2 BibleWelcome to Java 2 Enterprise Edition Bible. This book, which is a follow−up to Java 2 Bible, is for readers
who wish to know more about the enterprise market. Enterprise programming is a hot topic these days, as
more and more companies decide they need an online presence to complement their existing... | | With Alexander in India and Central Asia: Moving East and Back to West
Alexander conquered most parts of the Western World, but there is a great deal of controversy over his invasion of India, the least known of his campaigns. In BC 327 Alexander came to India, and tried to cross the Jhelum river for the invasion, but was then confronted by King Porus who ruled an area in what is now the Punjab. According to... |
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