Applying SOAP to OAI-PMH

The Web Services paradigm for distributed computing promises to provide a breakthrough in interoperability by defining standardised mechanisms for inter-process communication. The SOAP standard, in particular, is widely discussed but not as widely adopted by standards bodies. The OAI is one such organisation that has been criticised for not adopting SOAP. Since the OAI-PMH is driven by semantics and SOAP describes syntax, a merger of the two technologies seems natural and inevitable. This paper discusses an attempt to remodel and repackage the OAI-PMH as a layer over SOAP and implement an end-to-end solution based on this experimental protocol. The project highlighted important concerns, such as the relative efficiency of layering in structured textual data and the problem of moving standards. The results show that few compromises are needed for a move to SOAP provided that protocol design is appropriately abstracted, and this has far reaching implications for the adoption of SOAP and Web Services within the DL community and OAI in particular

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/

A bibliographic metadata infrastructure for the twenty-first century

The current library bibliographic infrastructure was constructed in the early days of computers – before the Web, XML, and a variety of other technological advances that now offer new opportunities. General requirements of a modern metadata infrastructure for libraries are identified, including such qualities as versatility, extensibility, granularity, and openness. A new kind of metadata infrastructure is then proposed that exhibits at least some of those qualities. Some key challenges that must be overcome to implement a change of this magnitude are identified

IVOA Recommendation: IVOA Registry Interfaces Version 1.0

Registries provide a mechanism with which VO applications can discover and select resources--e.g. data and services--that are relevant for a particular scientific problem. This specification defines the interfaces that support interactions between applications and registries as well as between the registries themselves. It is based on a general, distributed model composed of so-called searchable and publishing registries. The specification has two main components: an interface for searching and an interface for harvesting. All interfaces are defined by a standard Web Service Description Language (WSDL) document; however, harvesting is also supported through the existing Open Archives Initiative Protocol for Metadata Harvesting, defined as an HTTP REST interface. Finally, this specification details the metadata used to describe registries themselves as resources using an extension of the VOResource metadata schema

BlogForever D3.2: Interoperability Prospects

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

Building Digital Libraries from Simple Building Blocks

Metadata harvesting has been established by the Open Archives Initiative (OAI) as a viable mechanism for connecting a provider of data to a purveyor of services. The Open Digital Library (ODL) model is an emerging framework which attempts to break up the services into appropriate components based also on the basic philosophy of the OAI model. This framework has been applied to various projects and evaluated for its simplicity, extensibility and reusability to support the hypothesis that digital libraries (DLs) should be built from simple Web Service-like components instead of as monolithic software applications

Linked education: interlinking educational resources and the web of data

Research on interoperability of technology-enhanced learning (TEL) repositories throughout the last decade has led to a fragmented landscape of competing approaches, such as metadata schemas and interface mechanisms. However, so far Web-scale integration of resources is not facilitated, mainly due to the lack of take-up of shared principles, datasets and schemas. On the other hand, the Linked Data approach has emerged as the de-facto standard for sharing data on the Web and offers a large potential to solve interoperability issues in the field of TEL. In this paper, we describe a general approach to exploit the wealth of already existing TEL data on the Web by allowing its exposure as Linked Data and by taking into account automated enrichment and interlinking techniques to provide rich and well-interlinked data for the educational domain. This approach has been implemented in the context of the mEducator project where data from a number of open TEL data repositories has been integrated, exposed and enriched by following Linked Data principles

Web Services Approach to Library Feberated Search: Bangalore University Academic Library

The objective of this project is to setup a co-operative framework and develop a central index system for accessing the collections of all Affiliated College Libraries of Bangalore University. This is ought to be achieved by applying a new approach for search and retrieval via SRU/W combined with MARC and Dublin core meta-data paradigm; harvest meta-data using Open Archives Initiative – Protocol for Meta-data Harvesting. The project includes a server, client and portal, functionality partly running on Server and client browser resulting in a low implementation barrier, maximum scalability, and browser independence, as well as giving users control over the search interface and what collections to search

Libraries and Information Systems Need XML/RDF... but Do They Know It?

This article presents an approach to the uses of XML (eXtensible Markup Language) and Semantic Web technologies in the field of information services, focusing mainly on the creation and management of digital libraries compared to traditional libraries, while paying special attention to the concept and application of metadata, and RDF based integration

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