Active Digital Object

1

• Active Digital Object
• Repository Architecture
• ADORA

2
Presentation Overview

• 1 Project History
• 2 ADORA Digital Object Concepts
• 3 ADORA Extensibility Mechanism
• 4 ADORA Metadata Registry

3
Presentation Overview

• 1 Project History
• 2 ADORA Digital Object Concepts
• 3 ADORA Extensibility Mechanism
• 4 ADORA Metadata Registry

4
CNRIs Repository Project History

• Repository, Handle and Digital Object notions
  elaborated by Kahn and Wilensky
• Collaboration between CNRI and Cornell to further
  refine and elaborate the notions of digital
  objects and repositories.
• Implementation of a prototype repository for the
  Library of Congress.
• Implementation of a prototype repository for
  DTICs DVL.
• Interoperability experiments between CNRI and
  Cornell funded by the Dlib test suite.

5
Presentation Overview

• 1 Project History
• 2 ADORA Digital Object Concepts
• 3 ADORA Extensibility Mechanism
• 4 ADORA Metadata Registry

6
ADORA Digital Object
7
ADORA Digital Object

• Digital Objects are uniquely identified within a
  given domain name space.
• Digital Objects can store or reference sets of
  sequences of typed bytes.
• Digital Objects can associate their respective
  content with a set of extensible operations to
  reflect and enforce their creators assigned
  intended use.
• Digital Objects are accessed through
  disseminations.

8
ADORA Repository

• Repositories provide storage for Digital Objects.

• Repositories provide a secure environment in
  which all Digital Object disseminations are
  computed.

9
Digital Objects are Statefull
To be or not to be...
3rd edition
341 pages

• Digital Objects are network accessible using the
  Repository Access Protocol (RAP).
• Digital Objects maintain a unique sessions with
  each user.
• User interactions are contextualized.

10
Digital Object Have Handles
Get Digital Object CNRI/TEST
Client
11
Presentation Overview

• 1 Project History
• 2 ADORA Digital Object Concepts
• 3 ADORA Extensibility Mechanism
• 4 ADORA Metadata Registry

12
Concepts of Extensible Operations
13
Concepts of Extensible Operations
Identifier

• GetPage(page)
• GetNextPage()
• Getbibliography()
• Translate(Language)

Type Signature
Servlet

• How to GetPage(page) ?
• How to GetNextPage() ?
• How to Getbibliography() ?
• How Translate(Language) ?
• What Data to use ?

14
Extensible Operations Example
15
Presentation Overview

• 1 Project History
• 2 ADORA Digital Object Concepts
• 3 ADORA Extensibility Mechanism
• 4 ADORA Metadata Registry

16
ISO/IEC 11179 General Concepts

• ISO/IEC 11179 describes the standardizing and
  registering of metadata schemata to make them
  understandable and sharable.
• Provides a standard for formulating and
  maintaining metadata schemata element
  descriptions in a consistent manner.
• Provides guidance for establishing metadata
  description registries.

17
ISO/IEC 11179 Metadata Schema Description

• ISO 11179 defines a set of attributes for each
  element within any metadata schema.
• A Data Elements attributes describe the metadata
  element in the following categories
• Identifying
• Definitional
• Relational
• Representational
• Administrative

18
ISO/IEC 11179 Data Element Example Part 1

• D-LIB Magazine Metadata Schema
• Metadata element Title
• Identifying
• Name Title
• Unique Identifier Title
• Version 0.1
• Registration Authority Corporation for National
  Research Initiatives
• Definitional
• Definition The title of the D-Lib Magazine item
  being described.

19
ISO/IEC 11179 Data Element Example Part 2

• Relational
• Optional Fields
• Representational
• Representation Category ISO/IEC 10646
• Form of Representation text
• Data Type of Data element Value character
• Maximum Size of Value unlimited
• Minimum Size of Value 0
• Permissible Data Element Values
• Administrative
• Optional Fields

20
ISO/IEC 11179 Metadata Registry

• Promotes registration and acquisition of metadata
  schemata definitions.
• Enables the greater re-use of metadata schemata.
• Enhances the accuracy of new metadata.
• Enables for the interchange of metadata and data
  across computer systems and organizations.
• Facilitates the manipulation of metadata and data
  in software.

21
ADORA as a Metadata Registry

• ADORA provides distributed access to its Digital
  Objects.
• ADORA Digital Objects can have a wide range of
  content.
• ADORA Digital Objects provide a high level of
  abstraction over the data that they contain.
• ADORA Digital Objects provide a homogeneous
  interface to a heterogeneous set of contents.
• Digital Objects have a high level of integrity
  and protect their content from unauthorized
  access.

22
Beyond ISO/IEC 11179 Functionality

• ADORA registries can be integrated with metadata
  and data collections.
• ADORA registries provide a set of operations that
  can convert metadata elements from one schema to
  another.
• ADORA registries are extensible allowing the
  addition of new conversion operations.
• ADORA registries are interoperable and can easily
  be aggregated.
• ADORA enhances the ability to automatically
  process metadata and data.

23
Describing Metadata
DC.Title"Kita Yama (Japan)" DC.Creator
"Kertesz, Andre DC.Subject and Keywords"1968
DC.Definition Photograph etc...
Metadata
24
Metadata Registry Digital Object

• The Digital Object identifier and the
  disseminator ID are registered in the handle
  service

25
Metadata Digital Object

• The DLIB Metadata is encoded in a format that the
  DLIB Interoperable Metadata Servlet can process

26
Interoperable Metadata Using Digital Object
27
Extensible Metadata Conversion
-gt UCSB, DC
-gt UCSB Encoded Metadata
28
Repository as a Collection of Collections
Repository
Carnegie Mellon
Search Engine
CMU
Catalog Interface
CMU Catalog
Cornell
CU
Catalog Interface
Cornell Catalog
CMU Catalog Interface
Carnegie Mellon
UCSB
Cornell Catalog Interface
Cornell
29
Appendix

• Handle system integration
• Software Architecture
• Software Release
• ISO/IEC 11179

30
Handle System Integration
31
General System Overview
Client
RAP
Repository 1
Repository 2
Indexing Service
32
Software Architecture
33
Software Architectural Overview
Store
End Client
Object Persistence Layer
Store Interface API
Object Management Layer
Client
Repository
RAP Interface Layer
RAP Requests
RAP Replies
Transport Protocol
34
Software Release
35
Software Components
Administration Tool
Digital Object Browser
Client System
Development Tools
Client Library
RAP Definition
RAP
Repository
Repository
Repository
DBMS
Legacy System