1. Digital Library Architecture and Technology

2. Outline DL architecture Building blocks of DLs DL models
Components of DLs
DL open source software
Modern features in digital library architectures

3. Introduction
DLs contain a variety of materials, technologies, services and standards
The Web itself, LIS centres as well as database providers and vendors are all examples of information services that can play a role in DLs
Digital library architectures provide a view of the underlying structures and frameworks on which DLs are built

4. Digital library interface
Conceptual design of a digital library
E-journals
Online
databases
Remote digital
libraries
WWW
Search
interfaces
Search
interfaces
Search
interfaces
Search engines&
directories
Library
resources
Local digital
library
OPACs
Search
interface
Digital library interface
Users
Chowdhury (2002) Introduction to digital libraries…

5. Components of a DL system
Arms (1997) names the following components for digital libraries:
User interfaces
Repository
Handle system
Search system

6. Arms et al. An Architecture for Information in Digital Libraries
Arms et al. An Architecture for Information in Digital Libraries. D-Lib Magazine, February 1997.

7. User interfaces
User interface for end-users to get access to the library and its collections
User interface for librarians and system administrators who manage collections

9. Repository
Repositories store and manage digital objects and other information. A large digital library may have many repositories of various types, including modern repositories, legacy databases, and Web servers.
The repository access protocol (RAP). Is used to recognize the rights and permissions that need to be satisfied before a client can access a digital object.

10. Handle system
Handles are general purpose identifiers that can be used to identify digital objects, over long periods of time and to manage materials stored in any repository or database.
DOI: Digital Object Identifiers
Example: /NP /ISBN
Persistent Uniform Resource Locator (PURL) developed by OCLC – names the location of an object

12. Search system
There will be many indexes and catalogs in a digital library that can be searched to discover information before retrieving it from a repository.
These indexes may be independently managed and support a wide range of protocols.
Databases, information retrieval systems, and content management systems are examples

13. CRADDL architecture
Cornell Reference Architecture for Distributed Digital Libraries (CRADDL - pronounced "cradle"), a set of components that form the core of a digital library infrastructure.

14. CRADDL architecture
Content in the architecture is stored in the form of digital objects
The repository service provides the mechanisms for the deposit, storage, and access to digital objects
Digital Objects are identified by unique URNs
The index service provides the mechanism for discovery of digital objects via query
The collection service provides the mechanisms for the aggregation of access to sets of digital objects
User interface services or gateways provide human-centered entry points to the functionality of the digital library

15. CRADDL services

16. Components of a Digital Library
User
Interface
Gateway
Collection Services
Persistent
NAMES
Name
Service
Index
Services
Repository Services
Digital
Objects

17. Alexandria DL architecture
One of the six projects funded under the Digital Libraries Initiative (DLI),
A digital library of geospatial information, based at the University of California, Santa Barbara
Several databases, gazetteers and thesaurus
Sophisticated architecture

18. Alexandria Digital Library

19. Alexandria DL architecture
A three-tier model consisting of:
Servers
Middleware
Clients

20. Alexandria DL architecture
Servers: maintain collections of metadata describing the library’s holdings and for implementing query and retrieval mechanisms
Middleware: performs standard service on these collections
Clients: search sessions, list the library collections, retrieve metadata, and holdings

23. DL open source software
Greenstone
Fedora
D-space
Eprint

24. Greenstone
An open-source multilingual application developed by the New Zealand Digital Library Project at the University of Waikato
Developed and distributed in cooperation with UNESCO and the Human Info NGO.

25. Greenstone features Accessible through web browsers
Full text and fielded search
Browsing facilities
Facility to add DC metadata
Multimedia collections
Can support millions of documents
Collections can be published on CD-ROM

26. Fedora Flexible tools for managing and delivering digital content.
Jointly developed by Cornell University and the University of Virginia Library
National Science Digital Library (NSDL) uses Fedora
It supports the DC metadata format
It can run on MySQL and Oracle

27. DSpace digital repository system
Jointly developed by MIT Libraries and Hewlett-Packard Labs
Stores, indexes, preserves, and distributes digital research material.
Various applications: Institutional Repositories, Learning Object Repositories (LORs), eTheses , Electronic Records Management (ERM), Digital Preservation, Publishing

28. EPrints
Was developed at the University of Southampton, released in late 2000
The objective was to facilitate open access to peer-reviewed research and scholarly literature
EPrints serves as an archive for other electronic documents such as images and audio.
Currently installed in more than 241 institution.

29. Modern Features in
Digital Library Architectures

30. Social networking sites
Social networking, bookmarking and tagging
Reviews
Recommendation features
Citation and reference linking
Bibliometric tools

31. share Bookmark Tag Write reviews
Hull, D., Pettifer, S. R., and Kell, D. B. (2008). Defrosting the digital library: Bibliographic tools for the next generation web. PLoS Comput Biol, 4(10):e

32. Users interact with resources and create tags Tag 1 Tag2 Tag 3 Tag 1

33. Social Tagging
Environment
Photo sharing
Slide sharing
Videoblogging
and sharing
Social networks
Academic
bookmarking
Bookmarking

40. Citation
linking

41. Get it! Citation linker

43. Examples Greenstone: http://www.greenstone.org/examples Fedora: DSpace
Tufts University:
University of Viginia:
DSpace
U of A:
U of Wolverhampton(UK) :
Queen’s University:
EPrints
British Library:
E-LIS:
History and Theory of Psychology: