Antonio Tapiador

A Web Collaboration Architecture

Computer supported collaborative work (CSCW) has typically been bound within organizations. Groupware applications are designed with organizational structures in mind, in a top-down approach that predicts communication and collaboration interactions between people. With Internet adoption in society, CSCW overflows organizational borders towards Internet supported collaborative work (ISCW), where the organization of work becomes decentralized, centered on individual interests and pretty dynamic. This paper proposes a Web collaboration architecture for the new Web environment. The article reviews common groupware problems and reflects recent organizational changes. It presents Web 2.0 features and technical state-of-the-art. Then, it describes the architecture proposed, to finish with conclusions and future research lines

Social Stream, a social network framework

With the growing popularity of social network sites, it is appealing to develop social network frameworks (SNF) that alleviate the overhead associated with common social network features in social-enabled websites. This paper introduces Social Stream, a SNF. Social Stream has a modular architecture, mainly based in two supertypes. The first one is actor, which has the profile, establishes social relations and performs actions. The second one is object, which appears in the timeline and receives actors actions. Besides, Social Stream provides several major blocks: the social network, the activities timeline, actions and audiences. Social Stream has been sucessful out-of-the-box as contact-oriented network. Besides, it has been applied to the Virtual Science Hub (ViSH), an excursions content-oriented social network build in the context the EU-founded project Global Excursions. Most of the modules in the framework have been reused with slight modifications. Moreover, the framework has proven to be flexible enough to support different relation models (i.e. user-defined lists and system-defined follow), to support the definition of new content types that seamlessly integrate with social network features and to be able to fully customize home and profiles pages in the SNS.

Joint Degrees in E-Learning Systems: A Web Services Approach

In order to allow the development of joint degrees through heterogeneous e-learning systems, we propose a federation services architecture whose implementation will be based on Web services. Our main objective is to allow e-learning systems to be able to work in a collaborative way; combining their data and functionality through the integration of their services. These services will be combined and federated, according to collaboration agreements between Universities. Joint degrees through e-learning systems will allow the development of new joint curricula and the participation in the convergence of higher education

Enhance OpenStack Access Control via Policy Enforcement Based on XACML

The cloud computing is driving the future of internet computation, and evolutes the concepts from software to infrastructure. OpenStack is one of promising open-sourced cloud computing platforms. The active developer community and worldwide partners make OpenStack as a booming cloud ecosystem. In OpenStack, it supports JSON file based access control for user authorization. In this paper, we introduce a more powerful and complex access control method, XACML access control mechanism in OpenStack. XACML is an approved OASIS standard for access control language, with the capability of handling all major access control models. It has numerous advantages for nowadays cloud computing environment, include fine-grained authorization policies and implementation independence. This paper puts forward a XACML access control solution in OpenStack, which has Policy Enforcement Point (PEP) embedded in OpenStack cloud service and a XACML engine server with policy storage database. Our implementation allows OpenStack users to choose XACML as an access control method of OpenStack and facilitate the management work on policies.

Next-Generation Educational Web

The paper proposes the characterization of a converging approach for adult learning in both corporate and institutional environments and briefly presents iCamp - innovative, inclusive, interactive & intercultural learning Campus - project as the first implementation of an actual Next Generation Educational Web, supported by the emergent Web 2.0 “paradigm” and the social software technology behind it. It is intended to show you how the key elements under this blurry umbrella-like concept of Web 2.0 permeate the educational domain, allowing us to develop innovative pedagogical models, designed to be the basis of higher education, or adult learning in the same terms. The paper shows the first stages of our research efforts in iCamp through an integrated pedagogical model for supporting both, the traditional Learning Management Systems (LMS) / Learning Object Respositories (LOR), and the Personal Educational Environments (PLE) that comprise blogging and wiki tools as well as social networking services.

Implementation of an IPv6 Multihoming Ingress Filtering Compatibility Mechanism Using Automatic Tunnels

Nowadays, many organizations need to be multihomed in order to achieve fault tolerant Internet access. Unfortunately, the hierarchical nature of IPv6 addressing architecture poses some threats on multihoming. The IETF is designing a solution based on the discussion of several approaches to solve the problem. Ingress filters are part of the problem, so ingress filtering compatibility mechanisms are needed. This paper discusses the host-centric multihoming approach and describes an implementation of an ingress filtering compatibility mechanism based on automatic tunnels and anycast addresses. The implementation has proven to work properly, being easily developed and deployed.