Paulo Barthelmess

W-RBAC — A Workflow Security Model Incorporating Controlled Overriding of Constraints

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 service is the focus of the work, providing an expressive logic-based language for the selection of users authorized to perform workflow tasks, with preference ranking. W1-RBAC extends the basic model by incorporating exception handling capabilities through controlled and systematic overriding of constraints.

PROCLETS: A FRAMEWORK FOR LIGHTWEIGHT INTERACTING WORKFLOW PROCESSES

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 paper introduces and advocates the use of interacting proclets, i.e. lightweight workflow processes. By promoting interactions to first-class citizens it is possible to model complex workflows in a more natural manner. In addition, the expressive power and flexibility are improved compared to the more traditional workflow modeling languages.

DW-RBAC: A formal security model of delegation and revocation in workflow systems

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 assigned to roles and privileges to be associated with the roles. Thus, users can perform tasks based on the privileges possessed by their own role or roles they inherit by virtue of their organizational position. However, there is no easy way to handle delegations within this model. This paper tries to treat the issues surrounding delegation in workflow systems in a comprehensive way. We show how delegations can be incorporated into the RBAC model in a simple and straightforward manner. The new extended model is called RBAC with delegation in a workflow context (DW-RBAC). It allows for delegations to be specified from a user to another user, and later revoked when the delegation is no longer required. The implications of such specifications and their subsequent revocations are examined. Several formal definitions for assertion, acceptance, execution and revocation are provided, and proofs are given for the important properties of our delegation framework.

Workflow Modeling Using Proclets

The focus of traditional workflow management systems is on control flow within one process definition, that describes how a single case (i.e., work-flow instance) is handled in isolation. For many applications this paradigm is inadequate. Interaction between cases is at least as important. This paper introduces and advocates the use of interacting proclets, i.e., light-weight workflow processes. By promoting interactions to first-class citizens, it is possible to model complex workflows in a more natural manner, with improved expressive power and flexibility.

WorkFlow systems: a few definitions and a few suggestions

This paper hopes to make a contribution on three aspects of workflow systems: we stress the fact that there is a broken symetry between the level of the specification of the procedures and the level of their enactment; we propose some ways of classifying activities and exceptions; and we propose some run-time functionalities to help users deal with exceptions.

Tucupi: a flexible workflow system based on overridable constraints

This work presents the idea and a prototype of workflow systems whose definition is based on constraints. The flexibility is reached through the less rigid definition of workflow definitions - the workflow is defined as a set of pre and post conditions of activities, which are selected dynamically as the process instance unfolds. The workflow system besides dispatching activities that have all their preconditions fulfilled to be executed, also helps users to decide which activity to chose through what if scenarios. The system also includes an access control model which not only represents which users have the authority to chose and execute the activities but also the authority to override the constraints. In particular, overriding constraints is itself an activity and thus may have pre and post conditions defined in other constraints. The paper present Tucupi, a prototype of such constraint based WFMS.

Collaboration and Coordination in Process-Centered Software Development Environments: A Review of the Literature

Process-Centered Software Development Environments are systems that provide automated support for software development activities. Such environments mediate the eorts 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 present work, we survey and assess the contributions of the software pro- cess literature under the perspective of support for collaboration and coordination. A broad range of alternative approaches to various aspects of representation and runtime support are identified, based on the analysis of an expressive number of systems. The identified functionality can serve both as a guide for the evaluation and selection of systems of this kind as well as a roadmap for the development of new, improved systems.

Pro-active meeting assistants: attention please!

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 meeting effectiveness and efficiency can be improved by an assistant at all. 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 meeting effectiveness and efficiency can be improved by an assistant at all.

Collaborative multimodal photo annotation over digital paper

The availability of metadata annotations over media content such as photos is known to enhance retrieval and organization, particularly for large data sets. The greatest challenge for obtaining annotations remains getting users to perform the large amount of tedious manual work that is required.In this paper we introduce an approach for semi-automated labeling based on extraction of metadata from naturally occurring conversations of groups of people discussing pictures among themselves.As the burden for structuring and extracting metadata is shifted from users to the system, new recognition challenges arise. We explore how multimodal language can help in 1) detecting a concise set of meaningful labels to be associated with each photo, 2) achieving robust recognition of these key semantic terms, and 3) facilitating label propagation via multimodal shortcuts. Analysis of the data of a preliminary pilot collection suggests that handwritten labels may be highly indicative of the semantics of each photo, as indicated by the correlation of handwritten terms with high frequency spoken ones. We point to initial directions exploring a multimodal fusion technique to recover robust spelling and pronunciation of these high-value terms from redundant speech and handwriting.

The neem dream

Imagine an environment in which computerized agents assist in human to human interaction via voice, video, and other multi-media/multi-modal mechanisms. The Project Neem work introduces virtual participants Kwaku, Kwabena, and Kwesi - virtual participants who endeavor to make distributed meetings more effective, more efficient, and more pleasant.This document provides an overview of project Neem; its goals and directions, and its motivation. Neem is a research project at the University of Colorado concerned with understanding, enhancing and augmenting highly interactive distributed collaborations through advanced technology. A major novel aspect of this research is the use of intelligent artificial agents as full-fledged meeting participants. Goals of this interdisciplinary project include the enhancement of distributed group interaction understanding, and the creation and testing of prototype distributed meeting environments. With the encouragement and partnership of iAAEC (the Institute for African American Electronic Community), we have built and are testing a prototype distributed meeting system.Research methods include theoretical modeling, meetings analyses, prototype implementation and testing in real world environments, and meeting metrics development and application. Tools for understanding the social and organizational context of these meetings include the SYMLOG methodology applied by social agents, and the IBIS methodology applied by organizational agents. A new model enabling these agent analyses is the GraspIce model, explained in this document. The work described herein is part of a larger ongoing effort within the Collaboration Technology Research Group at the University of Colorado to understand human collaboration, and to assist and enhance that collaboration via technology.