33 research outputs found
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
File-based storage of Digital Objects and constituent datastreams: XMLtapes and Internet Archive ARC files
This paper introduces the write-once/read-many XMLtape/ARC storage approach
for Digital Objects and their constituent datastreams. The approach combines
two interconnected file-based storage mechanisms that are made accessible in a
protocol-based manner. First, XML-based representations of multiple Digital
Objects are concatenated into a single file named an XMLtape. An XMLtape is a
valid XML file; its format definition is independent of the choice of the
XML-based complex object format by which Digital Objects are represented. The
creation of indexes for both the identifier and the creation datetime of the
XML-based representation of the Digital Objects facilitates OAI-PMH-based
access to Digital Objects stored in an XMLtape. Second, ARC files, as
introduced by the Internet Archive, are used to contain the constituent
datastreams of the Digital Objects in a concatenated manner. An index for the
identifier of the datastream facilitates OpenURL-based access to an ARC file.
The interconnection between XMLtapes and ARC files is provided by conveying the
identifiers of ARC files associated with an XMLtape as administrative
information in the XMLtape, and by including OpenURL references to constituent
datastreams of a Digital Object in the XML-based representation of that Digital
Object.Comment: 12 pages, 1 figures (camera-ready copy for ECDL 2005
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 aDORe Federation Architecture
The need to federate repositories emerges in two distinctive scenarios. In
one scenario, scalability-related problems in the operation of a repository
reach a point beyond which continued service requires parallelization and hence
federation of the repository infrastructure. In the other scenario, multiple
distributed repositories manage collections of interest to certain communities
or applications, and federation is an approach to present a unified perspective
across these repositories. The high-level, 3-Tier aDORe federation architecture
can be used as a guideline to federate repositories in both cases. This paper
describes the architecture, consisting of core interfaces for federated
repositories in Tier-1, two shared infrastructure components in Tier-2, and a
single-point of access to the federation in Tier-3. The paper also illustrates
two large-scale deployments of the aDORe federation architecture: the aDORe
Archive repository (over 100,000,000 digital objects) at the Los Alamos
National Laboratory and the Ghent University Image Repository federation
(multiple terabytes of image files).Comment: 43 pages, 4 figures, 2 table
Increasing information feed in the process of structural steel design
Research initiatives throughout history have shown how a designer typically makes associations and references to a vast amount of knowledge based on experiences to make decisions. With the increasing usage of information systems in our everyday lives, one might imagine an information system that provides designers access to the ‘architectural memories’ of other architectural designers during the design process, in addition to their own physical architectural memory. In this paper, we discuss how the increased adoption of semantic web technologies might advance this idea. We investigate to what extent information can be described with these technologies in the context of structural steel design. This investigation indicates significant possibilities regarding information reuse in the process of structural steel design and, by extent, in other design contexts as well. However, important obstacles and question remarks can still be outlined as well