13,020 research outputs found

    Enabling the Autonomic Management of Federated Identity Providers

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    The autonomic management of federated authorization infrastructures (federations) is seen as a means for improving the monitoring and use of a service providerā€™s resources. However, federations are comprised of independent management domains with varying scopes of control and data ownership. The focus of this paper is on the autonomic management of federated identity providers by service providers located in other domains, when the identity providers have been diagnosed as the source of abuse. In particular, we describe how an autonomic controller, external to the domain of the identity provider, exercises control over the issuing of privilege attributes. The paper presents a conceptual design and implementation of an effector for an identity provider that is capable of enabling cross-domain autonomic management. The implementation of an effector for a SimpleSAMLphp identity provider is evaluated by demonstrating how an autonomic controller, together with the effector, is capable of responding to malicious abuse

    A distributed directory service for Greenstone

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    Greenstone is a software for creating and maintaining distributed digital library collections. It provides a sophisticated federation mechanism for the collections. In order to support alerting notification about changes in the distributed collections, we propose a distributed directory service for the management of the distributed Greenstone installations. The Greenstone directory service (GDS) acts on top of the distributed Greenstone structure for the management of collections. This paper describes both, the initial distributed Greenstone structure and the distributed directory service

    A Generic Alerting Service for Digital Libraries

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    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

    A distributed alerting service for open digital library software

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    Alerting for Digital Libraries (DL) is an important and useful feature for the library users. To date, two independent services and a few publisher-hosted proprietary services have been developed. Here, we address the problem of integrating alerting as functionality into open source software for distributed digital libraries. DL software is one application out of many that constitute so-called meta-software: software where its installation determines the properties of the actual running system (here: the Digital Library system). For this type of application, existing alerting solutions are insufficient; new ways have to be found for supporting a fragmented network of distributed digital library servers. We propose the design and usage of a distributed Directory Service. This paper also introduces our hybrid approach using two networks and a combination of different distributed routing strategies for event filtering

    Schema architecture and their relationships to transaction processing in distributed database systems

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    We discuss the different types of schema architectures which could be supported by distributed database systems, making a clear distinction between logical, physical, and federated distribution. We elaborate on the additional mapping information required in architecture based on logical distribution in order to support retrieval as well as update operations. We illustrate the problems in schema integration and data integration in multidatabase systems and discuss their impact on query processing. Finally, we discuss different issues relevant to the cooperation (or noncooperation) of local database systems in a heterogeneous multidatabase system and their relationship to the schema architecture and transaction processing

    Servicing the federation : the case for metadata harvesting

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    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

    BlogForever D3.2: Interoperability Prospects

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    This report evaluates the interoperability prospects of the BlogForever platform. Therefore, existing interoperability models are reviewed, a Delphi study to identify crucial aspects for the interoperability of web archives and digital libraries is conducted, technical interoperability standards and protocols are reviewed regarding their relevance for BlogForever, a simple approach to consider interoperability in specific usage scenarios is proposed, and a tangible approach to develop a succession plan that would allow a reliable transfer of content from the current digital archive to other digital repositories is presented

    Distribution of the Object Oriented Databases. A Viewpoint of the MVDB Model's Methodology and Architecture

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    In databases, much work has been done towards extending models with advanced tools such as view technology, schema evolution support, multiple classification, role modeling and viewpoints. Over the past years, most of the research dealing with the object multiple representation and evolution has proposed to enrich the monolithic vision of the classical object approach in which an object belongs to one hierarchy class. In particular, the integration of the viewpoint mechanism to the conventional object-oriented data model gives it flexibility and allows one to improve the modeling power of objects. The viewpoint paradigm refers to the multiple descriptions, the distribution, and the evolution of object. Also, it can be an undeniable contribution for a distributed design of complex databases. The motivation of this paper is to define an object data model integrating viewpoints in databases and to present a federated database architecture integrating multiple viewpoint sources following a local-as-extended-view data integration approach.object-oriented data model, OQL language, LAEV data integration approach, MVDB model, federated databases, Local-As-View Strategy.
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