Protocols for Integrity Constraint Checking in Federated Databases

A federated database is comprised of multiple interconnected database systems that primarily operate independently but cooperate to a certain extent. Global integrity constraints can be very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. This paper presents a threefold contribution to integrity constraint checking in federated databases: (1) The problem of constraint checking in a federated database environment is clearly formulated. (2) A family of protocols for constraint checking is presented. (3) The differences across protocols in the family are analyzed with respect to system requirements, properties guaranteed by the protocols, and processing and communication costs. Thus, our work yields a suite of options from which a protocol can be chosen to suit the system capabilities and integrity requirements of a particular federated database environment

Integrity Constraint Checking in Federated Databases

A federated database is comprised of multiple interconnected databases that cooperate in an autonomous fashion. Global integrity constraints are very useful in federated databases, but the lack of global queries, global transaction mechanisms, and global concurrency control renders traditional constraint management techniques inapplicable. The paper presents a threefold contribution to integrity constraint checking in federated databases: (1) the problem of constraint checking in a federated database environment is clearly formulated; (2) a family of cooperative protocols for constraint checking is presented; (3) the differences across protocols in the family are analyzed with respect to system requirements, properties guaranteed, and costs involved. Thus, we provide a suite of options with protocols for various environments with specific system capabilities and integrity requirement

Servicing the federation : the case for metadata harvesting

The paper presents a comparative analysis of data harvesting and distributed computing as complementary models of service delivery within large-scale federated digital libraries. Informed by requirements of flexibility and scalability of federated services, the analysis focuses on the identification and assessment of model invariants. In particular, it abstracts over application domains, services, and protocol implementations. The analytical evidence produced shows that the harvesting model offers stronger guarantees of satisfying the identified requirements. In addition, it suggests a first characterisation of services based on their suitability to either model and thus indicates how they could be integrated in the context of a single federated digital library

Discovery services: next generation of searching scholarly information

The new breed of resource discovery services is an evolutionary step forward in providing library users with a ‘one-stop shop’ where they can find information sources for their research. They provide a single search box that can search a library’s online and physical content including articles, books, journals, newspaper articles, e-books, specialist collections and more. These discovery services have built on the concepts of both federated searching and next-generation catalogues

Federated Embedded Systems – a review of the literature in related fields

This report is concerned with the vision of smart interconnected objects, a vision that has attracted much attention lately. In this paper, embedded, interconnected, open, and heterogeneous control systems are in focus, formally referred to as Federated Embedded Systems. To place FES into a context, a review of some related research directions is presented. This review includes such concepts as systems of systems, cyber-physical systems, ubiquitous computing, internet of things, and multi-agent systems. Interestingly, the reviewed fields seem to overlap with each other in an increasing number of ways

Library Resources: Procurement, Innovation and Exploitation in a Digital World

The possibilities of the digital future require new models for procurement, innovation and exploitation. Emma Crowley and Chris Spencer describe the skills staff need to deliver resources in hybrid and digital environments. The chapter demonstrates the innovative ways that librarians use to procure and exploit the wealth of resources available in a digital world. They also describe the technological developments that can be adopted to improve workflow processes and they highlight the challenges faced on this fascinating journey

A Generic Alerting Service for Digital Libraries

Users of modern digital libraries (DLs) can keep themselves up-to-date by searching and browsing their favorite collections, or more conveniently by resorting to an alerting service. The alerting service notifies its clients about new or changed documents. Proprietary and mediating alerting services fail to fluidly integrate information from differing collections. This paper analyses the conceptual requirements of this much-sought after service for digital libraries. We demonstrate that the differing concepts of digital libraries and its underlying technical design has extensive influence (a) the expectations, needs and interests of users regarding an alerting service, and (b) on the technical possibilities of the implementation of the service. Our findings will show that the range of issues surrounding alerting services for digital libraries, their design and use is greater than one may anticipate. We also show that, conversely, the requirements for an alerting service have considerable impact on the concepts of DL design. Our findings should be of interest for librarians as well as system designers. We highlight and discuss the far-reaching implications for the design of, and interaction with, libraries. This paper discusses the lessons learned from building such a distributed alerting service. We present our prototype implementation as a proof-of-concept for an alerting service for open DL software

Creating Legal Space for Community-based Fisheries and Customary Marine Tenure in the Pacific: Issues and Opportunities

The legal environment within which community-based fisheries management (CBFM) will function should be examined to determine whether it supports or will need necessary enhancement to support the implementation of CBFM. The question as to whether CBFM is legally sustainable must be asked with regard to the whole legal framework of the State – from fundamental laws, such as the constitution, to subsidiary legislation. Amendments to existing legislation or new legislation may be necessary to implement CBFM. There is no blueprint for a CBFM legal framework what number of rights with respect to fish resources should be accorded and what should be the level of participation by the local community. It is important, however, to ensure that the constitutionality of all these aspects is ascertained, and to ensure that enabling legislation for CBFM consider the following issues: security, exclusivity and permanence of rights vested; flexibility of its provisions so as to allow states to exercise choices that reflect their unique needs, conditions and aspirations for CBFM; and the way CBFM harmonizes with the overall fisheries management legal framework. Attaining the right balance in the CBFM legal framework, however, is difficult and depends largely on local circumstances. There is much interest in using customary marine tenure (CMT) as a basis for CBFM in the Pacific Island Countries (PICs). The laws of PICs lend general support to the use of CMT or tradition in fisheries management. Still, only modest efforts in the use of CMT-based community fisheries management in the PICs are observed. Further legislative action can enhance CMT use in community fisheries management. Broad lessons can be drawn from the experiences of some PICs in legislating on CMT or certain of its aspects to enhance CMT use. Government commitment to CBFM generally, and for the role of CMT in the CBFM context with support from interested entities and stakeholders including communities, will complement efforts for promoting sustainable utilization of fisheries resources and improved livelihoods in the PICs. Keywords: community-based fisheries management, customary marine tenure, fisheries legislation, legal frameworks, Pacific Island Countries

Co-evolution of RDF Datasets

Linking Data initiatives have fostered the publication of large number of RDF datasets in the Linked Open Data (LOD) cloud, as well as the development of query processing infrastructures to access these data in a federated fashion. However, different experimental studies have shown that availability of LOD datasets cannot be always ensured, being RDF data replication required for envisioning reliable federated query frameworks. Albeit enhancing data availability, RDF data replication requires synchronization and conflict resolution when replicas and source datasets are allowed to change data over time, i.e., co-evolution management needs to be provided to ensure consistency. In this paper, we tackle the problem of RDF data co-evolution and devise an approach for conflict resolution during co-evolution of RDF datasets. Our proposed approach is property-oriented and allows for exploiting semantics about RDF properties during co-evolution management. The quality of our approach is empirically evaluated in different scenarios on the DBpedia-live dataset. Experimental results suggest that proposed proposed techniques have a positive impact on the quality of data in source datasets and replicas.Comment: 18 pages, 4 figures, Accepted in ICWE, 201