Conceptual Clustering in Database Systems

Classes are an integral part of all semantic data models. Despite this, class formation in these data models is ad hoc due to the varied treatment of classes and because the issue of grouping instances into classes is considered an art rather than a science. It is the view of this paper that class formation be based on category theory through the use of an aJtribute-based purpose-dieected conceptual clustering technique. Several issues concerned with category theory, especially exception handling, are discussed. The emphasis in this approach is on reasoning at the instance level. Schema generation occurs as a result of conceptually clustering the underlying data instances and guiding this process by specifying a context in the form of a clustering seed. The use of this approach in the areas of schema integration, schema evolution and querying will be discussed. These facilities have been implemented on a database system based on the CANDIDE [3] semantic data model. CANDIDE is essentially an extended version of the tenn-subsumption languages known as the KL-ONE family of languages

MITOMAP: a human mitochondrial genome database—2004 update

MITOMAP (http://www.MITOMAP.org), a database for the human mitochondrial genome, has grown rapidly in data content over the past several years as interest in the role of mitochondrial DNA (mtDNA) variation in human origins, forensics, degenerative diseases, cancer and aging has increased dramatically. To accommodate this information explosion, MITOMAP has implemented a new relational database and an improved search engine, and all programs have been rewritten. System administrative changes have been made to improve security and efficiency, and to make MITOMAP compatible with a new automatic mtDNA sequence analyzer known as Mitomaster

SyD: A Middleware Testbed for Collaborative Applications over Small Heterogeneous Devices and Data Stores

Abstract. Currently, it is possible to develop a collaborative application running on a collection of heterogeneous, possibly mobile, devices, each potentially hosting data stores, using existing middleware technologies such as JXTA, BREW, compact.NET and J2ME. However, they require too many ad-hoc techniques as well as cumbersome and time-consuming programming. Our System on Mobile Devices (SyD) middleware, on the other hand, has a modular architecture that makes such application de-velopment very systematic and streamlined. The architecture supports transactions over mobile data stores, with a range of remote group invo-cation options and embedded interdependencies among such data store objects. The architecture further provides a persistent uniform object view, group transaction with Quality of Service (QoS) speci¯cations, and XML vocabulary for inter-device communication. This paper presents the basic SyD concepts, introduces the architecture and the design of the SyD middleware and its components. We also provide guidelines fo

A knowledge-based approach to integrating and querying distributed heterogeneous information systems

Issued as Federal cash transaction report, Project summary [nos. 1-2], Publications, and Final report, Project C-36-X2

Fundamentals of database systems

1010 p. : il.; 24 cm