Catálogo de publicaciones - libros

This paper presents and evaluates a multi-agent approach for range image segmentation. A set of reactive and autonomous agents perform a collective segmentation by partitioning a range image in its different planar regions. The agents move over the image and perform cooperative and competitive actions on the pixels, allowing a robust region extraction, and an accurate edge detection. An artificial potential field, created around the pixels of interest, ensures the agent coordination. It allows the agents to concentrate their actions around the edges and the noise regions. The experimental results show the potential of the proposed approach for scene understanding in range images, regarding both segmentation efficiency, and detection accuracy.

With the recent development of many model-checkers for the temporal logic of knowledge, abstraction techniques are necessary to increase the size of the systems that can be verified. In this paper, we introduce several abstraction techniques for interpreted systems and we prove several preservation results. These results consider the temporal logic of knowledge under Kleene’s 3-valued interpretation along infinite and maximal finite paths.

This paper presents an agent-based approach to Network Intrusion Prevention on corporate networks, emphasizing the protection from fast-spreading mobile malicious code outbreaks (e.g. worms) and related threats. Agents are not only used as a system-integration platform, but we use modern agent approaches to trust modeling and distributed task allocation to efficiently detect and also counter the attack by automatically created and deployed filters. The ability of the system to react autonomously, without direct human supervision, is crucial in countering the fast-spreading worms, that employ efficient scanning strategies to immediately spread farther once they infect a single host in the network.

In this paper we propose a dialogue game for agents to deliberate over a proposed action. The agents’ dialogue moves are defined by a structured set of argument schemes and critical questions (CQs). Thus, a dialogue move is an instantiated scheme ( an argument) or a CQ ( a challenge on the argument instantiated in the scheme). The proposed dialogue game formalises the protocol based exchange of arguments defined in the model. This model provides a setting for agents to deliberate over whether, given the arguments for and against, a proposed action is justified or not.

In this paper we introduce a formal attacker model for normative multi-agent systems. In this context, an attacker is an agent trying to profit from norm violation, for example because the violation is not detected, it is not being sanctioned, or the sanction is less than the profit of violation. To deliberate about norm violations, an attacker has a self model and a model of the normative multi-agent system, which in our case have the same structure. Moreover, we assume that an attacker violates a norm only when it profits from it, and the attacker therefore plays a violation game with the system. On a variety of examples, we show also how our model of violation games based also on agent abilities or power extends our earlier model based on motivations only.

Two-party communication is the most-studied model to support interaction between two cognitive agents, whereas that is only one case of what an agent should be able to do. Multi-party communications enhance this model, by taking into account all the roles an agent can have in a communication. Nevertheless, there are no generic models and infrastructures that enable to apply multi-party communication in a standardized way. We emphasize that the environment, in the sense of a common medium for the agents, is a suitable paradigm to support multi-party communication. We propose a general and operational model called Environment as Active Support of Interaction (EASI), that enables each agent to actively modify the environment according to its communication needs. Algorithms are proposed and assessed with an example stemming from the ambient intelligence domain.

In this paper, we introduce a formal-language interaction protocol for agent communication that may contribute to the building of better human-computer dialogues through a simulation of human language use. The paper centers on formal dialogue research. We introduce the definition of a formal model of dialogue based on Eco-Grammar Systems (EGS) and inspired in the Multi-Agent Protocol (MAP) language. The result is a simple formal device that could be used for the design of dialogue systems with limited human-like behaviour.

We present a multi-agent system designed to detect malicious traffic in high-speed networks. In order to match the performance requirements related to the traffic volume, the network traffic data is acquired by hardware accelerated probes in NetFlow format and preprocessed before processing by the detection agent. The proposed detection algorithm is based on extension of trust modeling techniques with representation of uncertain identities, context representation and implicit assumption that significant traffic anomalies are a result of potentially malicious action. In order to model the traffic, each of the cooperating agents uses an existing anomaly detection method, that are then correlated using a reputation mechanism. The output of the detection layer is presented to operator by a dedicated analyst interface agent, which retrieves additional information to facilitate incident analysis. Our performance results illustrate the potential of the combination of high-speed hardware with cooperative detection algorithms and advanced analyst interface.

Agent Communication Languages (ACLs) play a fundamental role in open multiagent systems where message exchange is the main if not the only way for agents to coordinate themselves. New proposals about ACL semantics based on social commitments aim at countering the shortcomings of the mainstream mental-state-based ones. The commitment solution does not come for free and calls for an adequate monitoring system that checks whether commitments are fulfilled or not.

Sharing information about profiles and offered competencies of individual members within an alliance of cooperating companies facilitates searching for potential members of Virtual Organizations. This paper presents a concept of structuring of the competencies as well as a prototype proving this concept. The prototype follows a naturally hybrid architecture of alliances that consists of mutually independent alliance partners, who may be supported by central institutions of the alliance. The use of the agent-based solution enables information sharing among partners in such distributed and dynamic environment.