Paulo Barthelmess

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This paper presents a pair of role-based access control models for workflow systems, collectively known as the W-RBAC models. The first of these models, W0-RBAC is based on a framework that couples a powerful RBAC-based permission service and a workflow component with clear separation of concerns for ease of administration of authorizations. The permission(More)
The focus of traditional workflow management systems is on control flow within one process definition. The process definition describes how a single case (i.e., workflow instance) in isolation is handled. For many applications this paradigm is inadequate. Interaction between cases to support communication and collaboration is at least as important. This(More)
The focus of traditional workflow management systems is on control flow within one process definition. The process definition describes how a single case (i.e. workflow instance) in isolation is handled. For many applications this paradigm is inadequate. Interaction between cases to support communication and collaboration is at least as important. This(More)
One reason workflow systems have been criticized as being inflexible is that they lack support for delegation. This paper shows how delegation can be introduced in a workflow system by extending the role-based access control (RBAC) model. The current RBAC model is a security mechanism to implement access control in organizations by allowing users to be(More)
Process-Centered Software Development Environments are systems that provide automated support for software development activities. Such environments mediate the efforts of potentially large groups of developers working on a common project. This mediation is based on runtime support for actual work performance based on formal representations of work. In the(More)
We view software development as a collaborative activity that is typically supported by a software development environment. Since these environments can significantly influence the collaborative nature of a software development project, it is important to analyze and evaluate their capabilities with respect to collaboration. In this paper, we present an(More)
This paper gives an overview of pro-active meeting assistants, what they are and when they can be useful. We explain how to develop such assistants with respect to requirement definitions and elaborate on a set of Wizard of Oz experiments, aiming to find out in which form a meeting assistant should operate to be accepted by participants, and whether the(More)
A problem faced by groups that are not co-located but need to collaborate on a common task is the reduced access to the rich multimodal communicative context that they would have access to if they were collaborating face-to-face. Collaboration support tools aim to reduce the adverse effects of this restricted access to the fluid intermixing of speech,(More)