Publications
432 results found
Toni F, Sergot M, 2011, Argumentation and answer set programming, Pages: 164-180, ISBN: 9783642208317
Argumentation and answer set programming are two of the main knowledge representation paradigms that have emerged from logic programming for non-monotonic reasoning. This paper surveys recent work on using answer set programming as a mechanism for computing extensions in argumentation. The paper also indicates some possible directions for future work. © 2011 Springer-Verlag Berlin Heidelberg.
Kafali O, Toni F, Torroni P, 2011, Collaborative diagnosis of exceptions to contracts, Pages: 1099-1100
Exceptions constitute a great deal of autonomous process execution. In order to resolve an exception, several participants should collaborate and exchange knowledge. We believe that argumentation technologies lend themselves very well to be used in this context, both for elaborating on possible causes of exceptions, and for exchanging the result of such elaboration. We propose an open and modular multi-agent framework for handling exceptions using agent dialogues and assumption-based argumentation as the underlying logic. Copyright © 2011, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved.
Fan X, Toni F, 2011, Conflict resolution with argumentation dialogues, Pages: 1029-1030
Conflicts exist in multi-agent systems for a number of reasons: agents have different interests and desires; agents hold different beliefs; agents make different assumptions. To resolve conflicts, agents need to better convey information to each other and facilitate fair negotiations yielding jointly agreeable outcomes. We present a two-agent, dialogical conflict resolution scheme developed with the Assumption-Based Argumentation (ABA) framework. Copyright © 2011, International Foundation for Autonomous Agents and Multiagent Systems (www.ifaamas.org). All rights reserved.
Kafali O, Toni F, Torroni P, 2011, Reasoning about Exceptions to Contracts, Publisher: SPRINGER-VERLAG BERLIN
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- Citations: 1
Mancarella P, Toni F, 2011, Computational logic in agent based systems, Intelligenza Artificiale, Vol: 5, Pages: 139-143, ISSN: 1724-8035
Fan X, Toni F, 2011, Assumption-Based Argumentation Dialogues, Pages: 198-203-198-203
McGinnis J, Stathis K, Toni F, 2010, A formal framework of virtual organisations as agent societies, Pages: 1-14, ISSN: 2075-2180
We propose a formal framework that supports a model of agent-based Virtual Organisations (VOs) for service grids and provides an associated operational model for the creation of VOs. The framework is intended to be used for describing different service grid applications based on multiple agents and, as a result, it abstracts away from any realisation choices of the service grid application, the agents involved to support the applications and their interactions. Within the proposed framework VOs are seen as emerging from societies of agents, where agents are abstractly characterised by goals and roles they can play within VOs. In turn, VOs are abstractly characterised by the agents participating in them with specific roles, as well as the workflow of services and corresponding contracts suitable for achieving the goals of the participating agents. We illustrate the proposed framework with an earth observation scenario.
Toni F, 2010, Argumentative agents, Pages: 223-229
Argumentation, initially studied in philosophy and law, has been researched extensively in computing in the last decade, especially for inference, decision making and decision support, dialogue, and negotiation. This paper focuses on the use of argumentation to support intelligent agents in multi-agent systems, in general and in the ARGUGRID project1 and Agreement Technology action2. In particular, the paper reviews how argumentation can help agents take decisions, either in isolation (by evaluating pros and cons of conflicting decisions) or in an open and dynamic environment (by assessing the validity of information they become aware of). It also illustrates how argumentation can support negotiation and conflict resolution amongst agents (by allowing them to exchange information and fill in gaps in their incomplete beliefs). Finally, the paper discusses how arguments can improve the assessment of the trustworthiness of agents in contract-regulated interactions (by supporting predictions on these agents' future behaviours). © 2010 IEEE.
Phan MD, Toni F, Mancarella P, 2010, Some design guidelines for practical argumentation systems, 3rd Conference on Computational Models of Argument, Publisher: IOS PRESS, Pages: 183-194, ISSN: 0922-6389
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- Citations: 13
Matt P-A, Toni F, Vaccari JR, 2010, Dominant Decisions by Argumentation Agents, Publisher: SPRINGER-VERLAG BERLIN
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- Citations: 7
Giordano L, Toni F, 2010, Knowledge Representation and Non-monotonic Reasoning, Publisher: SPRINGER-VERLAG BERLIN, Pages: 87-111, ISSN: 0302-9743
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- Citations: 1
Matt P-A, Morge M, Toni F, 2010, Combining statistics and arguments to compute trust., 9th International Conference on Autonomous Agents and Multiagent Systems (AAMAS'10), Publisher: IFAAMAS, Pages: 209-216
Fan X, Toni F, Hussain A, 2010, Two-Agent Conflict Resolution with Assumption-Based Argumentation, 3rd Conference on Computational Models of Argument, Publisher: IOS PRESS, Pages: 231-242, ISSN: 0922-6389
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- Citations: 7
Mancarella P, Toni F, 2009, Computational logic in agent based systems, CEUR Workshop Proceedings, Vol: 487, Pages: 70-75, ISSN: 1613-0073
We describe recent work on the deployment of computational logic to support the formalisation and implementation of agents in multi-agent systems. Several forms of computational logic systems are needed in this setting, including abductive, argumentative and preference-based systems. We briefly sketch the agent model called KGP, and an ongoing extension of it which is needed to model agents in distributed settings such as the Grid and, more generally, Service-oriented architectures.
Hussain A, Toni F, 2009, Assumption-based argumentation for communicating agents, Pages: 33-39
Assumption-Based Argumentation (ABA), and to a large extent argumentation in general, up to now has been considered in a single-agent setting. ABA, in particular, is such that an agent engages in a dispute (dialectic proof procedure) with itself (an imaginary opponent) to decide whether a claim is acceptable according to some acceptability criteria. We present in this paper a generalised proof procedure for the admissibility semantics of ABA, which is still a dispute by an agent with itself but such that the outcome can be readily communicated to other agents. This is important for applications in multi-agent systems wherein agents may differ in the knowledge they have and may need to communicate their arguments between one another to convince each other of the acceptability or not of a given claim. Copyright © 2009, Association for the Advancement of Artificial Intelligence. All rights reserved.
Mancarella P, Terreni G, Sadri F, et al., 2009, The CIFF proof procedure for abductive logic programming with constraints: Theory, implementation and experiments, THEORY AND PRACTICE OF LOGIC PROGRAMMING, Vol: 9, Pages: 691-750, ISSN: 1471-0684
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- Citations: 13
Gaertner D, Rodrlguez-Aguilar JA, Toni F, 2009, Agreeing on institutional goals for multi-agent societies, Pages: 1-16, ISSN: 0302-9743
We present an argumentation-based approach to the problem of finding a set of institutional goals for multi-agent systems. The behaviour of the autonomous agents we consider in this paper is goal- directed, driven by either individual or common goals. When multiple agents want to set up a collaboration framework (for themselves or others to use), they do so by forming an institution (or organisation). The goals of such institution must be agreed upon by the agents setting up the framework before it can be executed. We propose to use argumentation, and in particular assumption-based argumentation, to facilitate the negotiation of institutional goals. We first describe a centralised approach and then provide the rationale for and detail our preliminary efforts at de-centralising the problem. We propose to employ the argumentation system CaSAPI as a tool to reason about the collaborative goals of the institution. Our approach mitigates concerns about performance bottlenecks and vulnerability of the system while providing, to some extent, privacy to the individual members of the institution. © Springer-Verlag Berlin Heidelberg 2009.
Mancarella P, Terreni G, Toni F, 2009, Web Sites Repairing through Abduction, Electronic Notes in Theoretical Computer Science, Vol: 235, Pages: 137-152, ISSN: 1571-0661
We present a methodology and a tool for suggesting repairs to web sites that violate some given requirements in the form of web rules expressed in (an extension of) a fragment of Excerpt. The methodology consists in translating these web rules into abductive logic programs with constraints and process these by means of an existing general-purpose proof procedure, called CIFF. The tool, that we call CIFFWEB, consists of CIFF as well as the translation from rules to programs and from web sites to a suitable logical format. The tool extends an existing tool for simply checking web sites against web rules. © 2009.
Bromuri S, Urovi V, Morge M, et al., 2009, A multi-agent system for service discovery, selection and negotiation, Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS, Vol: 2, Pages: 1423-1424, ISSN: 1548-8403
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 deccntralised multi-agent system supporting the discovery, selection, and negotiation of services. Copyright © 2009, International Foundation for Autonomous Agents and Multiagent Systems.
Dung PM, Kowalski RA, Toni F, 2009, Assumption-Based Argumentation, ARGUMENTATION IN ARTIFICIAL INTELLIGENCE, Pages: 199-218
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- Citations: 115
Bromuri S, Urovi V, Morge M, et al., 2009, A multi-agent system for service discovery, selection and negotiation., Publisher: IFAAMAS, Pages: 1395-1396
Kakas A, Mancarella P, Sadri F, et al., 2008, Computational Logic Foundations of KGP Agents, JOURNAL OF ARTIFICIAL INTELLIGENCE RESEARCH, Vol: 33, Pages: 285-348, ISSN: 1076-9757
Toni F, 2008, Argumentative KGP agents for service composition, Pages: 67-72
We sketch a variant of the KGP agent model tailored to support service composition in service-oriented architectures. This allows to handle: user requirements, abstract and concrete workflows, possibly with annotations, inter-agent communication for supporting negotiation and persuasion, consultation of registries. We identify argumentation as core for Service-Oriented Architectures, and ground our work in the context of three concrete scenarios: e-procurement, earth observation, and business migration. Copyright © 2008, Association for the Advancement of Artificial Intelligence (www.aaai.org). All rights reserved.
Toni F, Guo L, 2008, The ArguGRID platform: An overview., Proceedings of the 5th international workshop on Grid Economics and Business Models. . GECON 2008
Toni F, Bentahar J, 2008, Computational logic-based agents, AUTONOMOUS AGENTS AND MULTI-AGENT SYSTEMS, Vol: 16, Pages: 211-213, ISSN: 1387-2532
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- Citations: 3
Hussain A, Toni F, 2008, On the benefits of argumentation for negotiation - preliminary version, Departmental Technical Report: 08/15, Publisher: Department of Computing, Imperial College London, 08/15
We present preliminary work on the benefits of argumentation-basednegotiation, for a simple framework for one-to-one negotiation betweenagents in a resource reallocation setting. Agents engage in dialogues withother agents in order to obtain resources they need but do not have. Di-alogues are regulated by simple communication policies that allow agentsto provide reasons (arguments) for their refusals to give away resources;agents use assumption-based argumentation in order to deploy these poli-cies. We assess the benefits of providing these reasons both informallyand experimentally: by providing reasons, agents are “more effective”in identifying a reallocation of resources if one exists and failing if noneexists.
Matt P-A, Toni F, 2008, A game-theoretic perspective on the notion of argument strength in abstract argumentation, Departmental Technical Report: 08/11, Publisher: Department of Computing, Imperial College London, 08/11
This paper is concerned with the problem of quantifying the strengthof arguments in controversial debates, which we model as abstract argumentationframeworks [Dung, 1995]. Standard approaches to abstract argumentation provideonly a qualitative account of the status of arguments, whereas numerical measuresof argument strength might provide a more precise evaluation of their individualstatus. Intuitively, the strength of an argument in a debate essentially depends onhow a proponent of that argument would defend himself against the criticisms ofsomeone opposed to the argument. Since there can be many ways of defending andattacking an opinion, we essentially conceive argument strength as an equilibriumresulting from the interactions taking place between the opinions that a proponentand an opponent of the argument could a priori embrace. More formally, we defineargument strength in terms of the value of a repeated two-person zero-sum strategicgame with imperfect information. Then, using the game-theoretic properties ofsuch games and notably the von Neumann minimax theorem [Neumann, 1928], weestablish and illustrate the main properties of this new argument strength measure.
Matt PA, Toni F, Stournaras T, et al., 2008, Argumentation-based agents for eProcurement, Proceedings of the International Joint Conference on Autonomous Agents and Multiagent Systems, AAMAS, Vol: 3, Pages: 1757-1760, ISSN: 1548-8403
Procurement is the complete process of obtaining goods and services - from preparation and processing of a requisition through to receipt and approval of the invoice for payment. The support for eProcurement is important for realising agent-based eBusiness applications. This paper proposes the use of argumentation-based agents to support the selection of suppliers for goods and services within the negotiation phase of procurement. Argumentation is used to compare candidate suppliers and identify the one that best meets the buyer's business-specific needs. The use of argumentation-based technology presents important advantages over traditional procurement methods such as competitive bidding, direct negotiation or single-source acquisition in that it can cope with qualitative uncertainty and preferences as well as the construction of contracts. We apply the method to the industrial procurement of an eOrdering system.
Matt P-A, Toni F, 2008, Constructing imprecise probabilities using arguments as evidence, Departmental Technical Report: 08/10, Publisher: Department of Computing, Imperial College London, 08/10
This paper addresses the problem of constructing subjective impreciseprobabilities using qualitative and conflicting pieces of information (arguments) asevidence.We propose formulae for the calculus of imprecise probabilities and showthat the probabilities obtained reflect the indeterminacy of the subject, faithfullyquantify the support offered by the arguments and constitute previsions that aremathematically coherent in the sense of [Walley, 1991].
Gaertner D, Toni F, 2008, Preferences and assumption-based argumentation for conflict-free normative agents, 4th International Workshop on Argumentation in Multiagent Systems, Publisher: SPRINGER-VERLAG BERLIN, Pages: 94-113, ISSN: 0302-9743
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- Citations: 2
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