Catálogo de publicaciones - libros

Our research is interested in behavioral animation among virtual reality applications. A major concern in this field is animating background actors and modeling their interactions. The aim is to provide virtual agents behaviors enabling them to evolve an autonomous and coordinated way in dynamic environments. The behavior is modeled through the standard perception/decision/action loop where the characteristics of the decision module determine the agent abilities. The artificial intelligence “cognitive” agents have reasoning capabilities upon symbolic representations of the objects surrounding them, the way humans do. The artificial life agents possess the reactive and adaptive features from life imitation techniques. The canvas of behavioral animation combine both approaches in order to obtain autonomous, coherent, reactive and adaptive agents. The so-called “hybrid” agents are for the most cognitive agents including reactive features. Two properties follow: they handle symbolic information and they store it in a memory regarded as a passive module. We propose a different approach, focused on memory. We consider memory as an active component of cognition and reasoning or intelligence as the emergent expression of its operating. While keeping an “artificial life” view, we propose an original hybrid architecture which avoids the traditional reactiveness/cognition dichotomy and relies on distributed implicit mental representations. Our model is a neural networks based architecture where two dimensions are considered: Whereas a vertical dimension models the procedural perception/action associations which form the reactiveness of a behavior, a horizontal dimension introduces the semantic concept association.

Epigenesis postulates that intelligence may arise in a system thanks to an adequate developmental process interacting with its environment. Robotics constitutes the most suitable field to implement this approach. This paper presents the underlying concept, an earlier proposal and a potential implementation of a prospective paradigm named Growing Functional Modules. This paradigm has been conceived to allow the design and the automatic development of a distributed and dynamic architecture able to gradually control an epigenetic robot. An illustration is given applying the paradigm to create a simple artificial brain for a mushroom shaped robot.

This paper presents a method to specify agent’s goals using process algebras. Formal specification of agent’s goal is important in goal oriented works because it allows more detailed description about what we want an agent to do and also is possible to detect possible problems. In this paper we present the method we use to specify formally agent’s goals in GeDA-3D a platform useful to implement distributed applications where a 3D interface is useful.

This paper presents a Paraconsistent Approach based on a heuristic of multi-valued decrement list followed by formalization into Evidential Paraconsistent Logic to evaluate offers in a negotiation session. The mission of an organization stands for its goals and also leads corrections likely to occur in the posture adopted by the organization before the society. In order to fulfill the goals of the organization, this one needs to interact with other components of the society. Within an organization each individual responsible for the sale and purchase of either commodities or services detains knowledge concerning possible values of the criteria used to represent a determined commodity or service which may be either offered or accepted in a negotiation. So, an offer may be seen as an inconsistency caused by the previous individual knowledge of the negotiator and the incoming offer. When compared to the Utility Value Approach , the Paraconsistent one converges toward the negotiation ending with fewer interactions.

This paper describes the design of a voice-enabled Personal Assistant to support users (civil servants) advising citizens in an e-Government multi-agent system. We present the assistant intelligent interface architecture, emphasizing the role of ontologies to knowledge handling and how the natural language dialogue is conducted. We also present a system overview, where agents are encapsulated as WEB Services. The main goal of this approach is to offer a system capable of performing tasks through an intuitive interface, allowing experienced and less experienced users to interact with it in an easy and comfortable way.

With the Web popularization, the digital inclusion comes motivating the research and development of engines of more sophisticated search each time concentrating in the concepts of the Web Semantics that incorporates semantic elements in the formatting of their concepts and propitiates a search with bigger intelligence. Such intelligence characterizes for the quality or precision of the knowledge retrieved or returned in reply to one determined request, involving a structure of how the knowledge is represented, accessed, retrieved, manipulated and enriched. The intention of this process is to enable to the executive professionals to interact naturally with computers using the natural language where the computers understand the submitted questions it and answer using the same terms of the question in understandable way, guiding them in complex decisions, allowing that they can occupy of nobler tasks, the businesses of their company.

This paper is within the scope of methodical approaches for producing flexible and reliable formal specifications of interactions protocols between agents in a multiagent system. The basic idea behind it is to define the agents as an abstract machines described by their behavior. Such machines are able to create agents, interact with other agents of a same working group via roles usin precise communication protocols. Our goal is to model the interaction between agents with a formal method that is able to check and then prove our initial UML specification. In order to obtain the final specification with this approach, we chose to use the B method and illustrated it with a case study.

Agents need some kind of autonomy to act in open and dynamic environments. However, the resulting behavior is not always well adapted to the situation. The use of models that combine different reasoning levels creates other difficulties. The management of the control transfer and balance between abstract time-consuming reasoning processes and reactive quick low-level behaviors are particularly complex. Our model is based on the self-observation and control of agents. The main topic is the inconsistency detection used to transfer the control between contiguous levels. This is detailed in the context of virtual pedestrians design.

Security considerations play an increasingly important role for distributed computing. In today’s Internet age, academia requires sharing, distributing, merging, changing information, linking applications and other resources within and among universities and other related organizations. Because e -learning systems are open, distributed and interconnected, then security becomes an important challenge in order to insure that interested actors only have access to the right information at the appropriate time. The purpose of this paper is to give an in-depth understanding of most important security challenges that can be relevant for distributed e -learning systems.

The component-based model is one possible response to the increased heterogeneity of distributed systems. This model allows developers to focus on applicative logic and leaves the implementation of the technical aspects to the component platform. However, the technical services themselves do not reap the advantages provided by the components. In this paper, we propose structuring the technical services as Fractal components. We demonstrate the benefits of such a proposition through a precise decomposition of the transactional service. We also introduce an application that uses our component-based transactional service. In order to show the feasibility of our solution, we present a prototype, which is both a component-based transactional service and a solution for building such a composition. The preliminary test results for our prototype are also presented.