SCAM

Team, 

Via google and rdf-ig-irc-scratchpad just came across this

http://scam.sourceforge.net/

What it is

"SCAM is a content archive management system, developed under the
supervision of the KMR group, in cooperation with the Swedish National
Agency for Education (Skolverket) and Uppsala Learning Lab. It can be used
as a web-based portfolio system or as an interoperable content archive. 

High emphasize on portability and flexibility has been made, which in turn
relies on standardization of both design and implementation. Efforts on this
subject have been one of main challenges during the development. Standards
involve metadata vocabularies, content packaging, authentication of users
and access control, system interfaces, etc. 

SCAM is entirely implemented in Java using the J2EE architecture as its
backbone and use RDF as the metadata representation format. Standards
include for example Dublin Core and IEEE LOM for metadata, and IMS Content
Packaging for structural information."

About the repository

"SCAM natively incorporates an RDF-binding of IMS Content Packaging as the
organizational schema. Roughly an IMS Manifest consists of two different
types of Components: Resources and Items. A Component X in SCAM-sence is a
subgraph defined as having an URI X as root-node ending with either a
literal or another URI. This graph can consist of several blank nodes
(bNodes) in between which are RDFs definition of nodes having no URI.
Outspoken, this graph is the metadata about X.

An Item is simply a Component being typed as an IMS Item. This little
differance significantly changes the way the repository treats the
Component. For instance if you remove an Item, all its sub-items will also
be removed. It is analogous to when you remove a folder in a filesystem, all
its sub-folders and files will be removed. In other words, you can compare
how a filesystem treats files, softlinks and folders to how the repository
treats Items and Resources. An Item corresponds to a softlink or a folder
depending on its structure, and a Resource corresponds to a file. Having
stated that, we can deduce that an Item is a collection of Components or a
reference to a Resource. A Manifest is a collection of Components assigned
in a certain context and can therefore be compared to a filesystem account."

Design

"The primary repository implementation by SCAM utilizes the Enterprise
JavaBean 2.0 (EJB) concept together with a relational database to provide a
persistent and scalable storage facility. The database can be just about any
SQL-enabled relational database. 

The business logic has been divided into several EJBs each responsible for a
specific set of operations. The EJBs are Stateless Session Beans using Bean
Managed Persistance (BMP). A package developed by HP Labs called Jena is
used to assist in the RDF-RDB layer. Jena is also used throughout the entire
SCAM architechture providing an API against RDF. Future refactoring of the
repository may include replacing Jena with an Entity Bean solution."

regards

Dr Mark H. Butler
Research Scientist                HP Labs Bristol
mark-h_butler@hp.com
Internet: http://www-uk.hpl.hp.com/people/marbut/

Received on Wednesday, 10 September 2003 11:18:48 UTC