Steven Willmott

Towards an argument interchange format

The theory of argumentation is a rich, interdisciplinary area of research straddling the fields of artificial intelligence, philosophy, communication studies, linguistics and psychology. In the last few years, significant progress has been made in understanding the theoretical properties of different argumentation logics. However, one major barrier to the development and practical deployment of argumentation systems is the lack of a shared, agreed notation or ‘interchange format’ for argumentation and arguments. In this paper, we describe a draft specification for an argument interchange format (AIF) intended for representation and exchange of data between various argumentation tools and agent-based applications. It represents a consensus ‘abstract model’ established by researchers across fields of argumentation, artificial intelligence and multi-agent systems. In its current form, this specification is intended as a starting point for further discussion and elaboration by the community, rather than an attempt at a definitive, all-encompassing model. However, to demonstrate proof of concept, a use case scenario is briefly described. Moreover, three concrete realizations or ‘reifications’ of the abstract model are illustrated.

Provenance in Agent-Mediated Healthcare Systems

People are increasingly cooperating to share electronic information and techniques throughout various industries. In healthcare applications, data (a single patients healthcare history), workflow (procedures carried out on that patient), and logs (a recording of meaningful procedural events) are often distributed among several heterogeneous and autonomous information systems. Understanding a patients treatment history can help healthcare providers make treatment decisions. Provenance-aware applications can facilitate this process by tracing events, event dependencies, and provider decisions across various healthcare institutions

Applying provenance in distributed organ transplant management

The use of ICT solutions applied to Healthcare in distributed scenarios should not only provide improvements in the distributed processes and services they are targeted to assist but also provide ways to trace all the meaningful events and decisions taken in such distributed scenario. Provenance is an innovative way to trace such events and decisions in Distributed Health Care Systems, by providing ways to recover the origin of the collected data from the patients and/or the medical processes. Here we present a work in progress to apply provenance in the domain of distributed organ transplant management.

Modelling Coalition Formation over Time for Iterative Coalition Games

Coalition formation problems arise when groups of agents need to work together to achieve tasks in an environment ¿ such as bidding for a contract or bulk buying goods. The work presented here shows how current theories for coalition formation can be combined with notions from iterative games to cover cases where populations of agents must solve coalition problems many times ¿ modelling a long series of coalition games rather than just a single one. The paper includes a problem formulation for iterative coalition games, experimental results for a simple coalition game world demonstrating how strong coalitions can emerge over time even from basic strategies and a discussion of the interactions between different strategies over time.

Technology diffusion: analysing the diffusion of agent technologies

Despite several examples of deployed agent systems, there remain barriers to the large-scale adoption of agent technologies. In order to understand these barriers, this paper considers aspects of marketing theory which deal with diffusion of innovations and their relevance to the agents domain and the current state of diffusion of agent technologies. In particular, the paper examines the role of standards in the adoption of new technologies, describes the agent standards landscape, and compares the development and diffusion of agent technologies with that of object-oriented programming. The paper also reports on a simulation model developed in order to consider different trajectories for the adoption of agent technologies, with trajectories based on various assumptions regarding industry structure and the existence of competing technology standards. We present details of the simulation model and its assumptions, along with the results of the simulation exercises.

CCL: expressions of choice in agent communication

When shall I fly to New York? Which airline should I choose? How are these related to which airport I arrive at, to how I might travel into the city and to where I choose to stay? Many current and potential applications of agents involve reasoning and communicating about multiple interrelated choices. To date, however, most proposals for communication in agent systems have provided little or no direct support for the type of communication required by these applications. To address this need, the paper describes the Constraint Choice Language (CCL): an agent content language designed to support agent problem solving by providing explicit representations of choices and choice problems.

Applying adversarial planning techniques to go

Approaches to computer game playing based on alpha-beta search of the tree of possible move sequences combined with a position evaluation function have been successful for many games, notably Chess. Such approaches are less successful for games with large search spaces and complex positions, such as Go, and we are led to seek alternatives. One such alternative is to model the goals of the players, and their strategies for achieving these goals. This approach means searching the space of possible goal expansions, typically much smaller than the space of move sequences. Previous attempts to apply these techniques to Go have been unable to provide results for anything other than a high strategic level or very open game positions. In this paper we describe how adversarial hierarchical task network planning can provide a framework for goal-directed game playing in Go which is also applicable both strategic and tactical problems.

Adapting Agent Communication Languages for Semantic Web Service Inter-Communication

The integration of semantic Web and Web services technologies promises to be one of the most promising new areas for development of intelligent Web applications. One challenging area where these technologies meet is in explicit definitions of meaning for the messages exchanged between Web services - in other words, semantic definitions of the meanings of data / commands exchanged in the execution of a Web services based application. While current approaches such as OWL-S tackle these elements in service groundings by mapping processes to function calls with specific arguments, agent communication languages could provide a potentially richer alternative. The work presented here shows how this could be done by mapping the existing agent communication language (FIPA-ACL, FIPA-SL and associated standards developed by the foundation for intelligent physical agents) into OWL based representations which may then be readily used in a Web services environment.

The benefits of environment adaptive organisations for agent coordination and network routing problems

Resource allocation tasks in communication networks involve challenging problems in the distribution of information and control. The paper presents an adaptive organisational structure to support coordination between agents performing quality of service routing tasks. Agents are able to change organisational relationships over time to match the network state (the task environment). Experimental results show that the adaptive organisation significantly improves agent coordination and routing performance when compared with an equivalent static organisational structure.

Exploring Social Networks in Request for Proposal Dynamic Coalition Formation Problems

In small scale multi-agent environments, every agent is aware of all of the others. This allows agents to evaluate the potential outcomes of their interaction for each of their possible interaction partners. However, this farsighted knowledge becomes an issue in large scale systems, leading to a combinatorial explosion in evaluation and is unrealistic in communication terms. Limited awareness of other agents is therefore the only plausible scenario in many large-scale environments. This limited awareness can be modeled as a sparse social network in which agents only interact with a limited subset of agents known to them. In this paper, we explore a model of dynamic multi-agent coalition formation in which agents are connected via fixed underlying social networks that exhibit different well known structures such as Small World, Randomand Scale Freetopologies. Agents follow different exploratory policies and are distributed in the network according to a variety of metrics. The primary results of the paper are to demonstrate different positive and negative properties of each topology for the coalition formation problem. In particular we show that despite positive properties for many problems, Small Worldtopologies introduce blocking factors which hinder the emergence of good coalition solutions in many configurations.