Catálogo de publicaciones - libros

This paper deals with the modeling and the automatic implementation of constraints in component based applications. Constraints have been assuming an ever more relevant role in modeling distributed systems as long as business rules implementation, design-by-contract practice, and fault-tolerance requirements are concerned. Nevertheless, component developers are not sufficiently supported by existing tools to model and implement such features. In this paper, we propose a set of tools that enable developers both to model component constraints and to automatically generate component skeletons that already implement such constraints.

It is almost impossible to distinguish and keep track of all the cooperative systems and computer-supported learning environments currently available. One of the key characteristics of any cooperative system is the chosen rights model. Most systems of this sort employ a model that is specifically tailored to application area, e.g. a number of fixed roles. This article begins by examining the different basic characteristics of access rights in the area of cooperative work, and then goes on to present an open and flexible rights model. In addition to covering classical access rights, this model enables rights to be delegated to others and inherited contextually. The presented model is implemented in the cooperative sTeam open-source work environment. Finally we will present some evaluation results of using sTeam at various courses at our university.

Knowledge intensive cooperative work requires emergent workflow management. Participants interact with the workflow engine and jointly redefine and activate workflow structure. To improve the usability of such systems we present reconfigurable notification mechanisms as well as shared task models that can be used from diverse clients at the same time focusing on different kinds of visualization and navigation.

Ontologies represent a widely accepted method for modelling structured knowledge spaces. Ontologies are particularly useful in modelling corporate or collective knowledge spaces. As such, they provide a vehicle for codifying the collected experience, best practices or common agreement of communities. Nonetheless, in practice, such knowledge must be tailored by practitioners to meet the challenges at hand. While tools for the construction of ontologies abound, we have found that many users are still reliant on human judgement instead of computational support when ontological knowledge must be tailored, personalized, customized and/or applied. In this paper, we examine some of the circumstances surrounding this state of affairs, and contemplate possible roles for computational support in these undertakings. We do this through based on our experiences with the Multilingual Dictionary of Lexicographical Terms (MDLT), a prototype of a linguistic database.

Spatial structure supporting applications offer an abstract level of what can be found in the real world. However, in many systems, objects are aligned straight, rotation is not possible, they can be resized easily and can hold more text than is visible on the screen. Paper and structures created with paper seem to be more limited: Straight alignment is not possible without spending much time; paper can hardly be resized without damaging it; and piles may fall down if they become too tall. However, a closer look shows that paper structures offer much more attributes and dependencies than any current spatial structure supporting application. In this article, we compare paper structures to a selection of computer applications. We argue that the observed small additions with paper carry information which improves finding and organizing.

In this paper, we propose a framework for component-based open hypermedia systems that provides developers with ready-made and extensible communication and distribution facilities. We begin by analyzing the requirements for such a framework through an examination of existing systems. We then describe our framework, and tie this back to related work in the metainformatics field.

Organising information is an important knowledge work activity that is frequently used in the work place and at home. Even though this task is an every day activity, it is nontrivial. Some tools exist that take advantage of our spatial and visual intelligence, but have some difficulties with creating a satisfying visualisation for the information. Visualisations built by users may not show the information in the most useful way, so important facts may not emerge in time, or at all. Information visualisation suggests possible methods by which to visualise various types of information. However, it focuses on existing and explicit structures. This paper suggests combining spatial hypertext with information visualisation techniques to allow users to organise their information more effectively.

Structure plays an important role in knowledge work. The overall goal of structural computing research is to provide effective support for knowledge workers. Structural computing research has reached a level of maturity, where it is relevant and essential to define and discuss common research directions. This paper presents an agenda for structural computing research. A conceptual architecture for a structural computing environment is presented to serve as a point of reference (framework) for discussing important issues facing the structural computing research community.

This paper is focusing on some interesting issues about service publicity and usability while trying to move from the classic Open Hypermedia Systems (OHSs) to structural aware environments. Although the step towards structural computing provides a stable basis for new generation systems, these systems inherit from OHSs some long-period problems and aspects. Moreover, new usability problems are rising due to the increment of structural servers’ complexity.

The emergence of Component-Based Open Hypermedia Systems aims at the releasing of Hypermedia and Web applications from the monocracy of link as the information structuring primitive. Instead, an open set of structure services, each one providing structure abstractions relevant to a specific domain, is offered to an open set of client applications. Nonetheless, the lack of an engineering framework guiding the development process of CB-OHS has a part in their limited exploitation. In this paper, we analyze the characteristics of CB-OHS from an engineering approach, and we propose a framework and a number of tools, supporting all phases of their development process.