Catálogo de publicaciones - libros

Exogenous dynamics play a central role in survival and evolution of institutions. In this paper, we develop an approach to automate part of this evolution process for electronic market places which bring together many online buyers and suppliers. In particular, for a given market place, we focus on other market places doing similar business, as a form of exogenous evolutionary factor. Automatically tracking and analyzing how other market places do their business has a number of difficulties; for example, different electronic markets- with similar purpose- might use different names for similar agent roles and tasks. In this paper, we argue that low level analysis of sequences of messages exchanged between agents within e-markets is an effective mechanism in integrating similar roles specifications, independent of what names these roles – or even the messages themselves – may take. We focus on the structure of messages (message schemas), sequences of message schemas, sets of sequences of message schemas to compare and integrate roles. Using statistical analysis over such structures we bypass the difficult problem of identifying semantics of roles and exchanged messages through their human readable names (syntactic forms). To allow such low level analysis, different e-market specifications are expressed using the same language. Our language of choice is a recently developed multi agent systems specification language, Islander 2.0. We illustrate our approach with example specifications and institutions simulation traces.

Argumentation is a ubiquitous but effective mode of interaction and dialogue in the human society. It has come to be known that argumentation has many implications to interaction among computational agents as well. After observing and discussing the tetralemma, which is said to characterize the Eastern thought, in this paper we propose an argumentation framework with the paraconsistent logic programming based on the tetralemma. It allows us to represent typical eastern modes of truth: $\top, \bot$ which are considered epistemic states of propositions. We introduce various notions for our argumentation framework, such as attack relations in terms of differences as a momentum of argumentation, argument justification, preferential criteria of arguments based on social norms, and so on, in a way proper to the four-valued paraconsistent logic programming. Finally, we provide the fixpoint semantics and dialectical proof theory for the argumentation framework. We illustrate our ideas with various argument examples.

The lack of formalism and rigor in existing multi-agents models often leads to ambiguities and different interpretations. Those weaknesses combined with the inherent complexity of multi-agents systems generate many problems in their development process. Using formal notations to specify multi-agents systems’ behavior makes it possible to produce precise description. This also offers a better support to their verification and validation process. The Maude language, based on rewriting logic, presents a rich notation supporting formal specification and implementation of concurrent systems. In this paper, we demonstrate the feasibility and the interest of formalizing the behavior of DIMA model’s agents with the Maude language. The elaborated formal approach captures the inherent aspects of a DIMA model. The generated Maude descriptions have been validated using the platform supporting this language. Moreover, the proposed approach is generic and extensible. It offers, in particular, the advantage of being applicable to all multi-agents systems based on DIMA architecture and presents interesting extension possibilities.

In multiagent systems, a cooperative action requires the mutual agreement of multiple agents which is generally achieved by exchanging messages. Any delay in message transfer will, however, delay the realization of agreement, and this may reduce the effectiveness of the cooperative action. One solution is to use speculative actions, actions taken before agreement is reached with the goal being to ”lock in” the benefits of the cooperative action; its downside is the penalty incurred in unwinding the speculative actions if indeed the agents do not reach agreement. In this framework, we have two risks; the risk of losing the benefits of the cooperative action and the risk of unwinding the speculative actions. It is clear that some form of risk management is needed. In this paper, we propose two risk management methods, the hybrid method and the leveled method, which are viewed as a single agent approach and a multiagent approach, respectively. We discuss their advantages using the meeting room reservation problem.

In this paper we propose a logical system combining the update logic of A. Baltag, L. Moss and S. Solecki (to which we will refer to by the generic term BMS, [BMS04]) with the belief revision theory as conceived by C. Alchouròn, P. Gärdenfors and D. Mackinson (that we will call the AGM theory, [GardRott95]) viewed from the point of view of W. Spohn ([Spohn90,Spohn88]). We also give a proof system and a comparison with the AGM postulates.

Exogenous dynamics play a central role in survival and evolution of institutions. In this paper, we develop an approach to automate part of this evolution process for electronic market places which bring together many online buyers and suppliers. In particular, for a given market place, we focus on other market places doing similar business, as a form of exogenous evolutionary factor. Automatically tracking and analyzing how other market places do their business has a number of difficulties; for example, different electronic markets- with similar purpose- might use different names for similar agent roles and tasks. In this paper, we argue that low level analysis of sequences of messages exchanged between agents within e-markets is an effective mechanism in integrating similar roles specifications, independent of what names these roles – or even the messages themselves – may take. We focus on the structure of messages (message schemas), sequences of message schemas, sets of sequences of message schemas to compare and integrate roles. Using statistical analysis over such structures we bypass the difficult problem of identifying semantics of roles and exchanged messages through their human readable names (syntactic forms). To allow such low level analysis, different e-market specifications are expressed using the same language. Our language of choice is a recently developed multi agent systems specification language, Islander 2.0. We illustrate our approach with example specifications and institutions simulation traces.

The lack of formalism and rigor in existing multi-agents models often leads to ambiguities and different interpretations. Those weaknesses combined with the inherent complexity of multi-agents systems generate many problems in their development process. Using formal notations to specify multi-agents systems’ behavior makes it possible to produce precise description. This also offers a better support to their verification and validation process. The Maude language, based on rewriting logic, presents a rich notation supporting formal specification and implementation of concurrent systems. In this paper, we demonstrate the feasibility and the interest of formalizing the behavior of DIMA model’s agents with the Maude language. The elaborated formal approach captures the inherent aspects of a DIMA model. The generated Maude descriptions have been validated using the platform supporting this language. Moreover, the proposed approach is generic and extensible. It offers, in particular, the advantage of being applicable to all multi-agents systems based on DIMA architecture and presents interesting extension possibilities.

This paper describes an intelligent mobile agent named picoPlangent that we developed for use with portable devices. picoPlangent is designed with a component-based architecture. The agent functions are implemented by a set of small components, and the arrangement of these components can be easily changed within the limits of the available resources of each portable device. Agent actions are described into the goal tree that realizes the flexible actions of the agent on portable devices. The picoPlangent architecture is simple and easy to implement on various devices. We implemented picoPlangent using J2SE on PCs, GCC on PDAs (Palm devices) and J2ME on cellular phones (iAppli/ezPlus).

In this paper we discuss the “safe to act” problem, a problem associated with the safe interleaving of acting and planning. We also discuss previous research that is relevant to this problem. We then propose a specific search strategy for a general hierarchical plan-space planner that pushes portions of the emerging plan to become “execution ready” as quickly as possible. Finally, we discuss a property, critical serialisability, that is sufficient for a domain to possess in order for these portions to be “safely” executed.

This paper proposes a new e-procurement model for a large number of buyers and sellers interacting via the Internet. The goal of e-procurement is to create a satisfactory match between buyers’ demand and sellers’ supply. From our real-world experience, we view e-procurement as a process of negotiation to increase the matching quality of two corresponding specifications: one for buyers’ demand and another for sellers’ supply. To model scalable e-procurement, we propose a co-adaptive matchmaking mechanism using mutual relevance feedback. In order to understand the nature of the mechanism, we have developed two types of software agents, called e-buyers and e-sellers, to simulate human buyers and sellers. Multiagent simulation results show that the matching quality is incrementally improved if agents adaptively change their specifications. A realistic example is also provided to discuss how to extend our simulation to real-world e-procurement infrastructure.