Schema matching in a peer-to-peer database system

Includes bibliographical references (p. 112-118).Peer-to-peer or P2P systems are applications that allow a network of peers to share resources in a scalable and efficient manner. My research is concerned with the use of P2P systems for sharing databases. To allow data mediation between peers' databases, schema mappings need to exist, which are mappings between semantically equivalent attributes in different peers' schemas. Mappings can either be defined manually or found semi-automatically using a technique called schema matching. However, schema matching has not been used much in dynamic environments, such as P2P networks. Therefore, this thesis investigates how to enable effective semi-automated schema matching within a P2P network

Mapster: A Peer-to-Peer Data Sharing Environment

This paper describes a system called Mapster that allows users in a P2P network to share their databases. The research addresses problems of heterogeneity and scalability in P2P databases. To provide fine-grained access to users’ databases, schema matching and a super-peer topology are used. The schema matching component allows information to be translated by semi-automatically determining the mappings between the databases within the P2P network. A super-peer topology enables the schema matching techniques to operate effectively in large, dynamic, heterogeneous networks

Developing a Basis for Knowledge Management: A Bayesian Network Approach

Knowledge Management (KM) is an evolving field that attempts to maximise and sustain the competitive advantage of a company through leveraging its knowledge resources. KM practises are often built on a foundation of knowledge transfer and knowledge sharing. Recently there has been an increase on the reliance of automated tools to perform these functions. Typical components of these tools include: querying large datasets, user profiling, user interfaces and recommender systems. Traditionally, these components have been implemented using different technologies. This paper describes an approach to building these components using a flexible architecture based on Bayesian Network technology. Finally the paper considers some of the advantages to adopting the latter approach

Single amino acid change alters specificity of the multi-allelic wheat stem rust resistance locus SR9

Most rust resistance genes thus far isolated from wheat have a very limited number of functional alleles. Here, we report the isolation of most of the alleles at wheat stem rust resistance gene locus SR9. The seven previously reported resistance alleles (Sr9a, Sr9b, Sr9d, Sr9e, Sr9f, Sr9g, and Sr9h) are characterised using a synergistic strategy. Loss-of-function mutants and/or transgenic complementation are used to confirm Sr9b, two haplotypes of Sr9e (Sr9e_h1 and Sr9e_h2), Sr9g, and Sr9h. Each allele encodes a highly related nucleotide-binding site leucine-rich repeat (NB-LRR) type immune receptor, containing an unusual long LRR domain, that confers resistance to a unique spectrum of isolates of the wheat stem rust pathogen. The only SR9 protein effective against stem rust pathogen race TTKSK (Ug99), SR9H, differs from SR9B by a single amino acid. SR9B and SR9G resistance proteins are also distinguished by only a single amino acid. The SR9 allelic series found in the B subgenome are orthologs of wheat stem rust resistance gene Sr21 located in the A subgenome with around 85% identity in protein sequences. Together, our results show that functional diversification of allelic variants at the SR9 locus involves single and multiple amino acid changes that recognize isolates of wheat stem rust

Electronic Properties of Alumino-Silicate Glass-Ceramics Containing Transition Metal Oxides.

Imperial Users onl

The turn toward creative work

In this Academy of Management Collections essay, we curate a set of articles from the Academy of Management family of journals that showcase the evolution of creativity research within organizational scholarship. The articles reveal a shift from the study of creativity exclusively as an outcome to the broader study of the dynamics of “creative work”—efforts to achieve creativity, whether successful or not. The former—creativity as an outcome—represents the critical early, foundational work that legitimized the study of creativity in organizations, brought needed methodological innovations, and established definitional anchors. Our collection provides evidence of an expansion toward the latter—the dynamics of creative work—in recent years. Over time, researchers have focused more on process and relationships, discovering a dynamic interplay. The collected articles are selected not to be exhaustive but to provoke further theoretical and empirical scholarship on creative work as an inclusive umbrella, ideally leading to a broader, more nuanced understanding of the conditions under which varied creative work processes and the outcomes of those processes emerge