Abstract
Factors such as the growing number of multimedia terminals, the constant increase of bandwidth available per user, and the large number of existing data sharing applications, are compelling users to generate and distribute their own content to restricted groups of other users. Inorder to support such scenario, we present an IMS-based solution that enables content distribution, in multicast, to groups of users, where the source of the content is also an end-user The proposed solution allows the source of content to configure the service, indicating a list of authorized receivers and both the transmission date and duration. Moreover, the proposed solution also allows the operator to manage the registered user profiles, to impose access control and to validate the configurations submitted by the users.

Abstract
Learning objects are not a new concept, being currently produced either according to existent specifications, or in an ad hoc way. However, a system that can easily classify them for automatic storage is still missing In this article we propose a repository of learning objects which is capable of automatic classification and categorization based on a semantic organization. The classification is based on a text extraction mechanism which then uses text mining methods. We present a methodology for the initial clustering of objects, and a technique for maintaining the organization with continuous arrival of new objects.

Abstract
The general available tools for analyzing interactions in online discussion forums appear to be insufficient to characterize groups of medium/large dimensions, as they are limited to provide general information of participation, access statistics and message posting. Our research contributes for analyzing and characterizing asynchronous online interactions applying the Social Network Analysis methodology, by providing e-learning platforms with an interactive graph - the iGraph - that illustrates, and analyses, students' interactions. In a graphical interface embedded in an open source learning management system we combine real-time graphs and numerical indicator to provide the educator with a more thorough understanding of relations between course participants. Preliminary results indicate that the iGraph enables an insightful characterization of the interactions between actors and their participations in discussion forums.

Abstract
In this paper we present the architecture of RTPM, a middle-ware framework aimed at supporting the development and management of information systems for high-speed public transportation systems. The framework is based on a peer-to-peer overlay infrastructure with the main focus being on providing a scalable, resilient, reconfigurable, highly available platform for real-time and QoS computing. Copyright 2008 ACM.

Abstract
AGILMAT is a web application designed to help students learn Mathematics, with focus on high-school algebra and calculus drills. A modular and extensible architecture and a wizard-based configuration interface decoupled from the system core are major design features of AGILMAT. The drill expressions are specified by grammars and constraints imposed by default profiles and user options, so that AGILMAT may support distinct learning levels and stages. The core system uses symbolic manipulation and automated reasoning to provide correct answers for the drills. The paper shows how AGILMAT may be used to create and customize drills automatically.

Abstract
This paper describes a communication model to integrate repositories of programming problems with other e-Learning software components. The motivation for this work comes from the EduJudge project that aims to connect an existing repository of programming problems to learning management systems. When trying to use the existing repositories of learning objects we realized that they are mainly specialized search engines and lack features for integration with other e-Learning systems. With this model we intend to clarify the main features of a programming problem repository, in order to enable the design and development of software components that use it. The two main points of this model are the definition of programming problems as learning objects and the definition of the core functions exposed by the repository. In both cases, this model follows the existing specifications of the IMS standard and proposes extensions to deal with the special requirements of automatic evaluation and grading of programming exercises. In the definition of programming problems as learning objects we introduced a new schema for meta-data. This schema is used to represent meta-data related to automatic evaluation that cannot be conveniently represented using the standard: the type of automatic evaluation; the requirements of the evaluation engine; or the roles of different assets - tests cases, program solutions, etc. In the definition of the core functions we used two different web services flavours - SOAP and REST - and described each function as an operation for each type of interface. We describe also the data types of the arguments of each operation. These data types consist mainly on learning objects and their identifications, but include also usage reports and queries using XQuery.