Accepted, Forthcoming



Papers from: 2009, 2008, 2007, 2006

 

 

  • Arguing over motivations within the V3A-architecture for self-adaptation
    Maxime Morge, Kostas Stathis and Laurent Vercouter UNIPI, RHUL
    Proc. of the 1st International Conference on Agents and Artificial Intelligence (ICAART), Porto, Portugal.
    Abstract:   The Vowel Agent Argumentation Architecture (V3A) is an abstract model by means of which an autonomous agent argues with itself to manage its motivations and arbitrate its possible internal conflicts. We propose an argumentation technique which specifies the internal dialectical process and a dialogue-game amongst internal components which can dynamically join/leave the game, thus having the potential to support the development of self-adaptive agents. We exemplify this dialectical representation of the V3A model with a scenario, whereby components of the agent's mind called facets can be automatically downloaded to argue an agent's motivation.

  • Dominant Decisions by Argumentation Agents
    P.-A. Matt, F. Toni and J. Vaccari
    Argumentation in Multi-Agent Systems, 6th International Workshop
    Abstract:   We introduce a special family of (assumption-based argumentation) frameworks for reasoning about the benefits of decisions. These frameworks can be used for representing the knowledge of intelligent agents that can autonomously choose the "best" decisions, given subjective needs and preferences of decision-makers they represent. We understand "best" decisions as dominant ones, giving more benefits than any other decisions. Dominant decisions correspond, within the family of argumentation frameworks considered, to admissible arguments. We also propose the use of degrees of admissibility of arguments as a heuristic to assess subjectively the value of decisions and rank them from "best"(dominant) to "worst". We extend this method to provide notion of relative value of decisions where preferences over benefits are taken into account. Finally, we show how our techniques can be successfully applied to the problem of selecting satellite images to monitor oil spills, to support electronic marketplaces for earth observation products.

  • A multi-agent system for service discovery, selection and negotiation
    S. Bromuri, V. Urovi, M. Morge, F. Toni and K. Stathis RHUL, UNIPI, Imperial
    Proc. of the 8th International Joint Conference on Autonomous Agents and Multiagent Systems (AAMAS) (2009) Demonstration. Budapest, Hungary
    Abstract:   Service-oriented computing can benefit from multi-agent system technologies by adopting the coordination mechanisms, interaction protocols, and decision-making tools designed for multi-agent systems. We demonstrate here the use of a fully decentralised multi-agent system supporting the discovery, selection, and negotiation of services.

  • An Unified Framework for Dialectical Proof Procedures in Argumentation
    Phan Minh Dung, Phan Minh Thang
    IJCAI-09, Pasadena, California, USA
    Abstract:   We present an unified methodology for representation and development of dialectical proof procedures in abstract argumentation based on the notions of legal environments and dispute derivations. A legal environment specifies the legal moves of the dispute parties while a dispute derivation describes the procedure structure. A key insight of this paper is that the opponent moves determine the soundness of a dispute while the completeness of a dispute procedure depends on the proponent moves.

  • Stabilization of Information Sharing for Queries Answering in Multiagent Systems
    Phan Minh Dung, Do Duc Hanh, Phan Minh Thang
    ICLP'09, Pasadena, California, USA
    Abstract:   We consider multiagent systems situated in unpredictable environments. Agents viewed as abductive logic programs with abducibles being literals the agent could sense or receive from other agents, must cooperate to provide answers to users as they may not have the knowledge or the capabilities to sense relevant changes in their environment. As their surroundings may change unpredictably, agents may provide wrong answers to queries. Stabilization refers to a capability of the agents to eventually answer queries correctly despite unpredictable environment changes and the incapability of many agents to sense such changes.It could be viewed as the correctness criterium of communicating cooperative multiagent systems. For efficiency, a piece of information obtained from other agents may be used to answer many queries. Surprisingly, this natural form of "information sharing" may be a cause of non–stabilization of multiagent systems. We formulate postulates and present a formal framework for studying stabilization with information sharing and give sufficient conditions to ensure it.

  • Toward a Common Framework for Dialectical Proof Procedure in Abstract Argumentation
    Phan Minh Thang, Phan Minh Dung and Nguyen Duy Hung
    Journal of Logic and Computation, Oxford University Press
    Abstract:   We present a common framework for dialectical proof procedures for computing credulous, grounded, ideal and sceptical preferred semantics of abstract argumentation. The framework is based on the notions of dispute derivation and base derivation. Dispute derivation is a dialectical notion first introduced for computing credulous semantics in assumption-based argumentation, and adapted here for computing credulous semantics and grounded semantics. Base derivation is introduced for two purposes: (i) to characterize all preferred extensions containing a given argument, and (ii) to represent backtracking in the search for a dispute derivation. We prove the soundness of the proof procedures for any argumentation frameworks and their completeness for general classes of finitary or finite-branching argumentation frameworks containing the class of finite argumentation frameworks as a subclass.We also discuss related results.

  • Modular Argumentation for Modelling Legal Doctrines of Performance Relief
    Phan Minh Dung, Phan Minh Thang and Nguyen Duy Hung
    ICAIL-2009, Barcelona, Spain
    Abstract:   Legal doctrines provide principles, guidelines and rules for dispute resolution in reasoning with cases. To apply legal doctrines, the context of a contract consisting of different knowledge bases about beliefs and expertise of contract parties as well as about common social, legal domains need to be established. Judges then decide legal outcomes by reasoning from factors drawn in contract contexts following legal doctrines. In this paper, we model this decision making by modular argumentation. We focus on legal doctrines in contract law, especially the doctrines of impossibility and frustration of purpose.

  • Playing with Agent Coordination Patterns in MAGE
    Visara Urovi, Kostas Stathis RHUL
    Coordination, Organization, Institutions and Norms in Agent Systems (COIN@AAMAS09), Budapest, Hungary
    Abstract:   MAGE (Multi-Agent Game Environment) is a logic-based framework that uses games as a metaphor for representing complex agent activities within an artificial society. More specifically, MAGE seeks to (a) reuse existing computational techniques for norm-based interactions and (b) complement these techniques with a coordination component to support complex interactions. The reuse part of MAGE relates physical actions that happen in an agent environment to count as valid moves of a game representing the social environment of an application. The coordination part of MAGE supports the construction of composite games built from component sub-games and corresponds to coordination patterns that support complex activities built from sub-activities. To illustrate the MAGE approach, we discuss how to use the framework to specify the coordination patterns required to form a virtual organisation in the context of a service-oriented scenario.

  • Modular Argumentation For Modelling Legal Doctrines in Common Law of Contract
    Phan Minh Dung, Phan Minh Thang
    Artificial Intelligence and Law Journal, Springer Verlag
    Abstract:   To create a programming environment for contract dispute resolution, we propose an extension of assumption-based argumentation into modular assumption-based argumentation in which different modules of argumentation representing different knowledge bases for reasoning about beliefs and facts and for representation and reasoning with the legal doctrines could be built and assembled together. A distinct novel feature of modular argumentation in compare with other modular logic-based systems like Prolog is that it allows references to different semantics in the same module at the same time, a feature critically important for application of argumentation in legal domains like contract dispute resolution where the outcomes of court cases often depend on whether credulous or skeptical modes of reasoning were applied by the contract parties. We apply the new framework to model the doctrines of contract breach and mutual mistake.

  • Assumption-based argumentation for the minimal concession strategy of agents engaged in resource negotiation.
    Maxime Morge, Philippe Mathieu and Paolo Mancarella UNIPI
    Proc. of 5ème Journées Francophones MODÈLES FORMELS de l'INTERACTION (MFI), Lannion, France.
    Abstract:   The main contribution of this paper is the realisation of the minimal concession strategy by means of assumption-based argumentation illustrated by an intuitive scenario of resource negotiation. Moreover, we claim here that the outcome of negotiations, which are guaranteed to terminate, is an optimal agreement (when possible) if the agents adopt the MC strategy.

  • Assumption-based argumentation for the minimal concession strategy
    Maxime Morge and Paolo Mancarella UNIPI
    Proc. of the 6th International Workshop on Argumentation in Multi-Agent Systems (ArgMAS), Budapest, Hungary
    Abstract:   In this paper we propose a realisation of the Minimal Concession (MC) strategy which has been theoretically validated. The main contribution of this paper is the integration of this intelligent strategy in a practical application by means of assumption-based argumentation. We claim here that the outcome of negotiations, which are guaranteed to terminate, is an optimal agreement (when possible) if the agents adopt the MC strategy.

  • Distributed Agent Environments in the Ambient Event Calculus
    Stefano Bromuri and Kostas Stathis RHUL
    Proc. of the 3rd ACM International Conference on Distributed Event-Based Systems (DEBS) (2009), to appear. Nashville, TN (USA)
    Abstract:   We study the development of distributed agent environments as distributed event-based systems specified in the Ambient Event Calculus (AEC). The AEC is a logic-based formalism that is developed here to support the representation of a distributed agent environment as a persistent composite structure evolving over time. Such a complex structure supports the interaction between agents, objects, and containers, entities that have their own external observable state and can be distributed over a network. Interactions between these entities are specified in terms of events that represent actions executed by agents on objects and other agents in the environment. When events happen they are stored in containers and are notified to agent sensors that subscribe to event descriptions and as a result perceive the interactions. The AEC formalism also allows changes caused by events to be delivered across distributed containers, according to the topology of the application environment. We illustrate the use of AEC and we show how to specify interactions within the GOLEM agent platform applied to a specific agent scenario.

  • Labellings and Games for Extended Argumentation Frameworks
    S. Modgil
    Proc. IJCAI 09, Twenty-first International Joint Conference on Artificial Intelligence
    Abstract:   Dung’s abstract theory of argumentation has become established as a general framework for various species of non-monotonic reasoning, and reasoning in the presence of conflict. A Dung framework consists of arguments related by attacks, and the extensions of a framework, and so the status of arguments, are defined under different semantics. Developments of Dung’s work have also defined argument labellings as an alternative way of characterising extensions, and dialectical argument game proof theories for establishing the status of individual arguments. Recently, Extended Argumentation Frameworks extend Dung’s theory so that arguments not only attack arguments, but attacks themselves. In this way, the extended theory provides an abstract framework for principled integration of meta-level argumentation about defeasible preferences applied to resolve conflicts between object level arguments. In this paper we formalise labellings and argument games for a selection of Dung’s semantics defined for the extended frameworks.

  • Virtual e-retailing environment in GOLEM.
    S. Bromuri, V. Urovi, P. Contreras and K. Stathis. RHUL
    Intelligent Environments (IE08). IET, Jul 2008. University of Washington, Seattle, USA
    Abstract:   We present a prototype multi-agent system whose goal is to support a 3D application for e-retailing. The prototype demonstrates how the use of agent environments can be amongst the most promising and flexible approaches to engineer e-retailing applications. We illustrate this point by showing how the agent environment GOLEM supports social interactions and how it combines them with semantic-web technologies to develop the e-retailing application. We also describe the features of GOLEM that allow a user to engage in e-retailing activities in order to explore the virtual social environment by searching and dynamically discovering new agents, products and services.

  • Assumption-Based Argumentation
    P.M. Dung, R.A. Kowalski, F. Toni AIT, Imperial
    Argumentation in AI, I. Rahwan and G. Simari (Eds.), Springer Verlag
    Abstract:   This paper presents a compact overview of assumption-based argumentaiton, its computational counterpart and several applications.

  • Intelligent Agents in the Service-Oriented World - An Industrial Experience Report
    Li Guo, Moustafa Ghanem,Vasa Curcin Nabeel Azam InforSense
    The 2009 IEEE / WIC / ACM International Conferences on Web Intelligence (WI'09).
    Abstract:   This paper provides an industrial experience perspective to the ARGUGRID approach to the integration of service oriented computing and multi-agent technologies.