Access Interfaces for Open Archival Information Systems based on the OAI-PMH and the OpenURL Framework for Context-Sensitive Services

In recent years, a variety of digital repository and archival systems have been developed and adopted. All of these systems aim at hosting a variety of compound digital assets and at providing tools for storing, managing and accessing those assets. This paper will focus on the definition of common and standardized access interfaces that could be deployed across such diverse digital respository and archival systems. The proposed interfaces are based on the two formal specifications that have recently emerged from the Digital Library community: The Open Archive Initiative Protocol for Metadata Harvesting (OAI-PMH) and the NISO OpenURL Framework for Context-Sensitive Services (OpenURL Standard). As will be described, the former allows for the retrieval of batches of XML-based representations of digital assets, while the latter facilitates the retrieval of disseminations of a specific digital asset or of one or more of its constituents. The core properties of the proposed interfaces are explained in terms of the Reference Model for an Open Archival Information System (OAIS).Comment: Accepted paper for PV 2005 "Ensuring Long-term Preservation and Adding Value to Scientific and Technical data" (http://www.ukoln.ac.uk/events/pv-2005/

Pathways: Augmenting interoperability across scholarly repositories

In the emerging eScience environment, repositories of papers, datasets, software, etc., should be the foundation of a global and natively-digital scholarly communications system. The current infrastructure falls far short of this goal. Cross-repository interoperability must be augmented to support the many workflows and value-chains involved in scholarly communication. This will not be achieved through the promotion of single repository architecture or content representation, but instead requires an interoperability framework to connect the many heterogeneous systems that will exist. We present a simple data model and service architecture that augments repository interoperability to enable scholarly value-chains to be implemented. We describe an experiment that demonstrates how the proposed infrastructure can be deployed to implement the workflow involved in the creation of an overlay journal over several different repository systems (Fedora, aDORe, DSpace and arXiv).Comment: 18 pages. Accepted for International Journal on Digital Libraries special issue on Digital Libraries and eScienc

The multi-faceted use of the OAI-PMH in the LANL Repository

This paper focuses on the multifaceted use of the OAI-PMH in a repository architecture designed to store digital assets at the Research Library of the Los Alamos National Laboratory (LANL), and to make the stored assets available in a uniform way to various downstream applications. In the architecture, the MPEG-21 Digital Item Declaration Language is used as the XML-based format to represent complex digital objects. Upon ingestion, these objects are stored in a multitude of autonomous OAI-PMH repositories. An OAI-PMH compliant Repository Index keeps track of the creation and location of all those repositories, whereas an Identifier Resolver keeps track of the location of individual objects. An OAI-PMH Federator is introduced as a single-point-of-access to downstream harvesters. It hides the complexity of the environment to those harvesters, and allows them to obtain transformations of stored objects. While the proposed architecture is described in the context of the LANL library, the paper will also touch on its more general applicability

A schema-based P2P network to enable publish-subscribe for multimedia content in open hypermedia systems

Open Hypermedia Systems (OHS) aim to provide efficient dissemination, adaptation and integration of hyperlinked multimedia resources. Content available in Peer-to-Peer (P2P) networks could add significant value to OHS provided that challenges for efficient discovery and prompt delivery of rich and up-to-date content are successfully addressed. This paper proposes an architecture that enables the operation of OHS over a P2P overlay network of OHS servers based on semantic annotation of (a) peer OHS servers and of (b) multimedia resources that can be obtained through the link services of the OHS. The architecture provides efficient resource discovery. Semantic query-based subscriptions over this P2P network can enable access to up-to-date content, while caching at certain peers enables prompt delivery of multimedia content. Advanced query resolution techniques are employed to match different parts of subscription queries (subqueries). These subscriptions can be shared among different interested peers, thus increasing the efficiency of multimedia content dissemination

Multimedia repositories in learning and teaching – lessons from the MIDESS Project

The MIDESS project brought together 4 UK universities to explore the management of digitised content through the development of a digital repository infrastructure. The project focused on multimedia materials in particular and looked at how support can be provided for their use in a learning and research context and how resources can be shared both within and between institutions. Three repositories were implemented, using Fedora, DSpace and Digitool respectively. Material suitable for ingest was identified and the dialogue with academic partners in each institution helped clarify not only the complexity of the interactions required but also the value of the repository in supporting learning, teaching and research. Having established a repository platform within each institution, the project then explored how multimedia content could be exchanged and shared between the repositories, using OAI-PMH and METS as transport mechanisms. This paper will summarise the project’s main findings. In particular, it will address how a multimedia repository might fit into the information architecture of the university, the likely requirements for integration into an inter-institutional or national framework and some of the obstacles which can impede such integration. Scenarios will be presented illustrating how student learning can benefit from such a repository within a research-intensive university and the relationship between the repository and the VLE will be discussed

aDORe: a modular, standards-based Digital Object Repository

This paper describes the aDORe repository architecture, designed and implemented for ingesting, storing, and accessing a vast collection of Digital Objects at the Research Library of the Los Alamos National Laboratory. The aDORe architecture is highly modular and standards-based. In the architecture, the MPEG-21 Digital Item Declaration Language is used as the XML-based format to represent Digital Objects that can consist of multiple datastreams as Open Archival Information System Archival Information Packages (OAIS AIPs).Through an ingestion process, these OAIS AIPs are stored in a multitude of autonomous repositories. A Repository Index keeps track of the creation and location of all the autonomous repositories, whereas an Identifier Locator registers in which autonomous repository a given Digital Object or OAIS AIP resides. A front-end to the complete environment, the OAI-PMH Federator, is introduced for requesting OAIS Dissemination Information Packages (OAIS DIPs). These OAIS DIPs can be the stored OAIS AIPs themselves, or transformations thereof. This front-end allows OAI-PMH harvesters to recurrently and selectively collect batches of OAIS DIPs from aDORe, and hence to create multiple, parallel services using the collected objects. Another front-end, the OpenURL Resolver, is introduced for requesting OAIS Result Sets. An OAIS Result Set is a dissemination of an individual Digital Object or of its constituent datastreams. Both front-ends make use of an MPEG-21 Digital Item Processing Engine to apply services to OAIS AIPs, Digital Objects, or constituent datastreams that were specified in a dissemination request.Comment: Draft of submission to Computer Journa