Author : G. Grahne
Publisher : Springer Science & Business Media
Page : 174 pages
File Size : 13,49 MB
Release : 1991-11-13
Category : Computers
ISBN : 9783540549192
Reviews of Environmental Contamination and Toxicology publishes authoritative reviews on the occurrence, effects, and fate of pesticide residues and other environmental contaminants. It will keep you informed of the latest significant issues by providing in-depth information in the areas of analytical chemistry, agricultural microbiology, biochemistry, human and veterinary medicine, toxicology, and food technology.
Author : Gösta Grahne
Publisher :
Page : 0 pages
File Size : 28,96 MB
Release : 1989
Category : Relational databases
ISBN : 9789514549410
Abstract: "In practice it is often the case that the available information is incomplete with respect to the information that is supposed to be recorded in the database. We consider the problems raised by this situation in the context of the relational model. The basic semantic assumption is that an incomplete database is a set of complete databases (relations). We show that there are two natural lattice structures on the set of all sets of relations. These lattices enable us to give precise meanings to operations performed on incomplete databases. The operations are querying, dependency enforcement and updates. There are several candidate tools for storing and manipulating databases with incomplete information. We focus on generalizations of relations
Author : Gosta Grahne
Publisher :
Page : 172 pages
File Size : 27,78 MB
Release : 2014-09-11
Category :
ISBN : 9783662207529
Author : Segio Greco
Publisher : Morgan & Claypool Publishers
Page : 125 pages
File Size : 27,10 MB
Release : 2012-08-15
Category : Computers
ISBN : 1608459276
The chase has long been used as a central tool to analyze dependencies and their effect on queries. It has been applied to different relevant problems in database theory such as query optimization, query containment and equivalence, dependency implication, and database schema design. Recent years have seen a renewed interest in the chase as an important tool in several database applications, such as data exchange and integration, query answering in incomplete data, and many others. It is well known that the chase algorithm might be non-terminating and thus, in order for it to find practical applicability, it is crucial to identify cases where its termination is guaranteed. Another important aspect to consider when dealing with the chase is that it can introduce null values into the database, thereby leading to incomplete data. Thus, in several scenarios where the chase is used the problem of dealing with data dependencies and incomplete data arises. This book discusses fundamental issues concerning data dependencies and incomplete data with a particular focus on the chase and its applications in different database areas. We report recent results about the crucial issue of identifying conditions that guarantee the chase termination. Different database applications where the chase is a central tool are discussed with particular attention devoted to query answering in the presence of data dependencies and database schema design. Table of Contents: Introduction / Relational Databases / Incomplete Databases / The Chase Algorithm / Chase Termination / Data Dependencies and Normal Forms / Universal Repairs / Chase and Database Applications
Author : Sergio Greco
Publisher : Springer Nature
Page : 111 pages
File Size : 20,34 MB
Release : 2022-06-01
Category : Computers
ISBN : 3031018931
The chase has long been used as a central tool to analyze dependencies and their effect on queries. It has been applied to different relevant problems in database theory such as query optimization, query containment and equivalence, dependency implication, and database schema design. Recent years have seen a renewed interest in the chase as an important tool in several database applications, such as data exchange and integration, query answering in incomplete data, and many others. It is well known that the chase algorithm might be non-terminating and thus, in order for it to find practical applicability, it is crucial to identify cases where its termination is guaranteed. Another important aspect to consider when dealing with the chase is that it can introduce null values into the database, thereby leading to incomplete data. Thus, in several scenarios where the chase is used the problem of dealing with data dependencies and incomplete data arises. This book discusses fundamental issues concerning data dependencies and incomplete data with a particular focus on the chase and its applications in different database areas. We report recent results about the crucial issue of identifying conditions that guarantee the chase termination. Different database applications where the chase is a central tool are discussed with particular attention devoted to query answering in the presence of data dependencies and database schema design. Table of Contents: Introduction / Relational Databases / Incomplete Databases / The Chase Algorithm / Chase Termination / Data Dependencies and Normal Forms / Universal Repairs / Chase and Database Applications
Author : Amihai Motro
Publisher : Springer Science & Business Media
Page : 473 pages
File Size : 23,53 MB
Release : 2012-12-06
Category : Computers
ISBN : 1461562457
As its title suggests, "Uncertainty Management in Information Systems" is a book about how information systems can be made to manage information permeated with uncertainty. This subject is at the intersection of two areas of knowledge: information systems is an area that concentrates on the design of practical systems that can store and retrieve information; uncertainty modeling is an area in artificial intelligence concerned with accurate representation of uncertain information and with inference and decision-making under conditions infused with uncertainty. New applications of information systems require stronger capabilities in the area of uncertainty management. Our hope is that lasting interaction between these two areas would facilitate a new generation of information systems that will be capable of servicing these applications. Although there are researchers in information systems who have addressed themselves to issues of uncertainty, as well as researchers in uncertainty modeling who have considered the pragmatic demands and constraints of information systems, to a large extent there has been only limited interaction between these two areas. As the subtitle, "From Needs to Solutions," indicates, this book presents view points of information systems experts on the needs that challenge the uncer tainty capabilities of present information systems, and it provides a forum to researchers in uncertainty modeling to describe models and systems that can address these needs.
Author : Dov M. Gabbay
Publisher : Springer Science & Business Media
Page : 564 pages
File Size : 26,22 MB
Release : 1994-06-29
Category : Computers
ISBN : 9783540582410
This volume constitutes the proceedings of the First International Conference on Temporal Logic (ICTL '94), held at Bonn, Germany in July 1994. Since its conception as a discipline thirty years ago, temporal logic is studied by many researchers of numerous backgrounds; presently it is in a stage of accelerated dynamic growth. This book, as the proceedings of the first international conference particularly dedicated to temporal logic, gives a thorough state-of-the-art report on all aspects of temporal logic research relevant for computer science and AI. It contains 27 technical contributions carefully selected for presentation at ICTL '94 as well as three surveys and position papers.
Author :
Publisher :
Page : 980 pages
File Size : 44,39 MB
Release : 1990
Category : Aeronautics
ISBN :
Author : Gloria Bordogna
Publisher : Physica
Page : 240 pages
File Size : 35,59 MB
Release : 2013-03-19
Category : Computers
ISBN : 3790818453
First of all, I would like to congratulate Gabriella Pasi and Gloria Bordogna for the work they accomplished in preparing this new book in the series "Study in Fuzziness and Soft Computing". "Recent Issues on the Management of Fuzziness in Databases" is undoubtedly a token of their long-lasting and active involvement in the area of Fuzzy Information Retrieval and Fuzzy Database Systems. This book is really welcome in the area of fuzzy databases where they are not numerous although the first works at the crossroads of fuzzy sets and databases were initiated about twenty years ago by L. Zadeh. Only five books have been published since 1995, when the first volume dedicated to fuzzy databases published in the series "Study in Fuzziness and Soft Computing" edited by J. Kacprzyk and myself appeared. Going beyond books strictly speaking, let us also mention the existence of review papers that are part of a couple of handbooks related to fuzzy sets published since 1998. The area known as fuzzy databases covers a bunch of topics among which: -flexible queries addressed to regular databases, -the extension of the notion of a functional dependency, -data mining and fuzzy summarization, -querying databases containing imperfect attribute values represented thanks to possibility distributions.
Author : François Bancilhon
Publisher : Morgan Kaufmann
Page : 508 pages
File Size : 20,62 MB
Release : 1988-12
Category : Computers
ISBN : 9780934613750
