A Mathematical Model of Dialog

AbstractComputer Science is currently undergoing a paradigm shift, from viewing computer systems as isolated programs to viewing them as dynamic multi-agent societies. Evidence of this shift is the significant effort devoted recently to the design and implementation of languages and protocols for communications and interaction between software agents. Despite this effort, no formal mathematical theory of agent interaction languages and protocols yet exists. We argue that such a theory needs to account for the semantics of agent interaction, and propose the first mathematical theory which does this. Our framework incorporates category-theoretic entities for the utterances made in an agent dialog and for the commitments incurred by those utterances, together with maps between these

Case-Based Argumentation Framework. Dialogue Protocol

On top of the simpler ability to interact, open MAS must include mechanisms for their agents to reach agreements by taking into account their social context. Argumentation provides MAS with a framework that assures a rational communication, which allows agents to reach agreements when conflicts of opinion arise. In this report we present the communication protocol that agents of a case-based argumentation framework use to interact when they engage in argumentation dialogues. The syntax and semantics of the framework are formalised and discussed.Heras Barberá, SM.; Botti Navarro, VJ.; Julian Inglada, VJ. (2011). Case-Based Argumentation Framework. Dialogue Protocol. http://hdl.handle.net/10251/1109

Modelling dialogues in agent societies

Besides the simpler ability to interact, open multi-agent systems must include mechanisms for their agents to reach agreements by taking into account their social context. Argumentation provides multi-agent systems with a framework that assures a rational communication, which allows agents to reach agreements when conflicts of opinion arise. In this paper, we present the dialogue protocol that agents of a case-based argumentation framework can use to interact when they engage in argumentation dialogues. The syntax and semantics of the argumentation protocol are formalised and discussed. To illustrate our proposal, we have applied the protocol in the context of a water market. By using our dialogue protocol, agents represent water users that are able to explore different water allocations and justify their views about what is the best water distribution in a certain environment.This work is supported by the Spanish government Grants CONSOLIDER INGENIO 2010 CSD2007-00022, MINECO/FEDER TIN2012-36586-C03-01, and MICINN TIN2011-27652-C03-01.Heras Barberá, SM.; Botti Navarro, VJ.; Julian Inglada, VJ. (2014). Modelling dialogues in agent societies. Engineering Applications of Artificial Intelligence. 34:208-226. https://doi.org/10.1016/j.engappai.2014.06.003S2082263

An Interleaving Semantics of the Timed Concurrent Language for Argumentation to Model Debates and Dialogue Games

Time is a crucial factor in modelling dynamic behaviours of intelligent agents: activities have a determined temporal duration in a real-world environment, and previous actions influence agents' behaviour. In this paper, we propose a language for modelling concurrent interaction between agents that also allows the specification of temporal intervals in which particular actions occur. Such a language exploits a timed version of Abstract Argumentation Frameworks to realise a shared memory used by the agents to communicate and reason on the acceptability of their beliefs with respect to a given time interval. An interleaving model on a single processor is used for basic computation steps, with maximum parallelism for time elapsing. Following this approach, only one of the enabled agents is executed at each moment. To demonstrate the capabilities of language, we also show how it can be used to model interactions such as debates and dialogue games taking place between intelligent agents. Lastly, we present an implementation of the language that can be accessed via a web interface. Under consideration in Theory and Practice of Logic Programming (TPLP).Comment: Under consideration in Theory and Practice of Logic Programming (TPLP

Case-Based Argumentation in Agent Societies

Hoy en día los sistemas informáticos complejos se pueden ven en términos de los servicios que ofrecen y las entidades que interactúan para proporcionar o consumir dichos servicios. Los sistemas multi-agente abiertos, donde los agentes pueden entrar o salir del sistema, interactuar y formar grupos (coaliciones de agentes u organizaciones) de forma dinámica para resolver problemas, han sido propuestos como una tecnología adecuada para implementar este nuevo paradigma informático. Sin embargo, el amplio dinamismo de estos sistemas requiere que los agentes tengan una forma de armonizar los conflictos que surgen cuando tienen que colaborar y coordinar sus actividades. En estas situaciones, los agentes necesitan un mecanismo para argumentar de forma eficiente (persuadir a otros agentes para que acepten sus puntos de vista, negociar los términos de un contrato, etc.) y poder llegar a acuerdos. La argumentación es un medio natural y efectivo para abordar los conflictos y contradicciones del conocimiento. Participando en diálogos argumentativos, los agentes pueden llegar a acuerdos con otros agentes. En un sistema multi-agente abierto, los agentes pueden formar sociedades que los vinculan a través de relaciones de dependencia. Estas relaciones pueden surgir de sus interacciones o estar predefinidas por el sistema. Además, los agentes pueden tener un conjunto de valores individuales o sociales, heredados de los grupos a los que pertenecen, que quieren promocionar. Las dependencias entre los agentes y los grupos a los que pertenecen y los valores individuales y sociales definen el contexto social del agente. Este contexto tiene una influencia decisiva en la forma en que un agente puede argumentar y llegar a acuerdos con otros agentes. Por tanto, el contexto social de los agentes debería tener una influencia decisiva en la representación computacional de sus argumentos y en el proceso de gestión de argumentos.Heras Barberá, SM. (2011). Case-Based Argumentation in Agent Societies [Tesis doctoral no publicada]. Universitat Politècnica de València. https://doi.org/10.4995/Thesis/10251/12497Palanci

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks

Argumentation-based dialogues over cooperative plans

If autonomous agents operating with other agents in open systems are to fulfil their goals and design objectives, the need to discuss and agree upon plans of action is imperative. In this thesis I present work covering both theoretical research and practical development related to the use of argumentation-based dialogues as a way to coordinate actions in multi-agent planning scenarios. The necessity of coordination in multi-agent systems requires the development of mechanisms to propose, modify, share, monitor, and argue about plans. In this thesis I present an argumentation scheme to propose multi-agent plans and associated critical questions to critique the proposal. Such a detailed consideration of multi-agent plan composition contains the right characteristics to enable the justification of plans.This research builds upon research on practical reasoning for action proposals and considers multi-agent plan proposals where plans require several agents for their execution. A dialogue game protocol is also presented which is based on proposal framework. The protocol allows agents to engage in dialogues to agree on and modify plans based on persuasion and deliberation protocols. The detail encompassed by the argumentation scheme and critical questions means that there is a large number of critical questions, and so dialogues may be very lengthy. To overcome this issue, I investigated the issue of strategies for use with this dialogue game in terms of the different possible orderings in which critiques can be posed. The thesis presents an implementation that realises the theoretical framework in terms of a agents engaging in simulated dialogues to share and agree on a plan. The experiments allow us to investigate the effects of such strategies in terms of the number of questions issued to reach an agreement. Overall, the framework presented in this thesis allow agents to engage in dialogues over cooperative plan proposals in a structured way using well-founded argumentative principles

State-of-the-art on evolution and reactivity

This report starts by, in Chapter 1, outlining aspects of querying and updating resources on the Web and on the Semantic Web, including the development of query and update languages to be carried out within the Rewerse project. From this outline, it becomes clear that several existing research areas and topics are of interest for this work in Rewerse. In the remainder of this report we further present state of the art surveys in a selection of such areas and topics. More precisely: in Chapter 2 we give an overview of logics for reasoning about state change and updates; Chapter 3 is devoted to briefly describing existing update languages for the Web, and also for updating logic programs; in Chapter 4 event-condition-action rules, both in the context of active database systems and in the context of semistructured data, are surveyed; in Chapter 5 we give an overview of some relevant rule-based agents frameworks