Exploiting simple corporate memory in iterative coalition games

Amongst the challenging problems that must be addressed in order to create increasingly automated electronic commerce systems are those which involve forming coalitions of agents to exploit a particular market opportunity. Furthermore economic systems are normally continuous dynamic systems generating many instances of the same or similar problems (the regular calls for tender, regular emergence of new markets etc.).The work described in this paper explores how simple forms of memory can be exploited by agents over time to guide decision making in iterative sequences of coalition formation problems enabling them to build up social knowledge in order to improve their own utility and the ability of the population to produce increasingly well suited coalitions for a simple call-for-tender economy.Postprint (published version

Adding X-security to Carrel: security for agent-based healthcare applications

The high growth of Multi-Agent Systems (MAS) in Open Networks with initiatives such as Agentcities1 requires development in many different areas such as scalable and secure agent platforms, location services, directory services, and systems management. In our case we have focused our effort on security for agent systems. The driving force of this paper is provide a practical vision of how security mechanisms could be introduced for multi-agent applications. Our case study for this experiment is Carrel [9]: an Agent-based application in the Organ and Tissue transplant domain. The selection of this application is due to its characteristics as a real scenario and use of high-risk data for example, a study of the 21 most visited health-related web sites on the Internet discovered that personal information provided at many of the sites was being inadvertently leaked for unauthorized persons. These factors indicate to us that Carrel would be a suitable environment in order to test existing security safeguards. Furthermore, we believe that the experience gathered will be useful for other MAS. In order to achieve our purpose we describe the design, architecture and implementation of security elements on MAS for the Carrel System.Postprint (published version

Provenance-based trust for grid computing: Position Paper

Current evolutions of Internet technology such as Web Services, ebXML, peer-to-peer and Grid computing all point to the development of large-scale open networks of diverse computing systems interacting with one another to perform tasks. Grid systems (and Web Services) are exemplary in this respect and are perhaps some of the first large-scale open computing systems to see widespread use - making them an important testing ground for problems in trust management which are likely to arise. From this perspective, today's grid architectures suffer from limitations, such as lack of a mechanism to trace results and lack of infrastructure to build up trust networks. These are important concerns in open grids, in which "community resources" are owned and managed by multiple stakeholders, and are dynamically organised in virtual organisations. Provenance enables users to trace how a particular result has been arrived at by identifying the individual services and the aggregation of services that produced such a particular output. Against this background, we present a research agenda to design, conceive and implement an industrial-strength open provenance architecture for grid systems. We motivate its use with three complex grid applications, namely aerospace engineering, organ transplant management and bioinformatics. Industrial-strength provenance support includes a scalable and secure architecture, an open proposal for standardising the protocols and data structures, a set of tools for configuring and using the provenance architecture, an open source reference implementation, and a deployment and validation in industrial context. The provision of such facilities will enrich grid capabilities by including new functionalities required for solving complex problems such as provenance data to provide complete audit trails of process execution and third-party analysis and auditing. As a result, we anticipate that a larger uptake of grid technology is likely to occur, since unprecedented possibilities will be offered to users and will give them a competitive edge

APPLICATION OF SURFACE EMG DECOMPOSITION TO IDENTIFY CHANGES IN NEUROMUSCULAR CONTROL DURING FATIGUING EXERCISE

The purpose of this study was to apply surface EMG decomposition to identify changes in neuromuscular control of lower limb muscles during fatiguing exercise. Trained participants (n=15) completed a repeat sprints cycling fatigue protocol. Motor unit firing rates and motor unit recruitment timings were identified for six muscles. A moderate to strong correlation between firing rates and recruitment timings were identified for individual participant data (r = -0.46 to r = -1.00). No significant group effects were reported when each muscle was examined independently (repeat measures ANOVA; slope, intercept; F \u3c 1.84, p \u3e 0.119). However, changes in regression parameters were indentified for individual participant data. Surface EMG decomposition provides a novel approach for identifying individual changes in neuromuscular control of lower limb muscles during fatiguing exercise

Agent Communication Semantics for Open Environments: Issues and Challenges

Explicit communication semantics are often considered essential for rich interaction between heterogeneous automated systems. While extensive work on semantic models has been carried out, much of this work remains to be tested in real open environments. This paper briefly describes some of the issues and challenges to be considered when combining existing semantic frameworks for effective agent communication. In particular, we describe issues related to the development of the Agentcities Network which is a large-scale open test bed for agent systems that aims to enable on-line experimentation with semantic frameworks for agent communication. The presentation is kept discursive in nature: characterizing different aspects of communication, outlining research challenges, commenting on possible strategies and describing the current status of activities in the Agentcities Network

Challenges in Large-Scale Open Agent Mediated Economies

Technology developments such as Web Services, GRID Computing and peer-to-peer toolkits are rapidly changing the way systems deployed in public networks interact. Large-scale usage of these technologies would very likely lead to environments which have many of the features commonly considered in Agent mediated e-commerce research: large-scale, dynamic populations of automated trading systems. This paper discusses the possibility of developing a large-scale open, agent based ``economy'' to act as a challenging test environment for electronic commerce solutions based on agent technology. Such an environment would allow researchers and developers to better understand the properties and characteristics of their systems whilst stopping short of deploying them in a real-economic environment. Although we describe some preliminary work in the context of the Agentcities initiative we intend this paper primarily as fuel for discussion

Enterprise Java Beans, Distributed Artificial Intelligence and Group Communication

Today's Middleware is facing increasing pressures to operate in more open, loosely coupled and complex environments. E-business systems require seamless transactions between multiple enterprises and software components are becoming more opaque in an effort to hide their complexity. In parallel, interactions between components are becoming increasingly sophisticated. This paper describes: - The integration of a well known standards compliant agent platform with a transactional J2EE application server to create a hybrid middleware able to make use of high level agent communication and other features. - An solution for Group Communication (GC) (a known Distributed Systems problem) using the hybrid middleware. - The extension of GC to illustrate how new challenges in distributed applications might be dealt with by a convergence of Distributed Systems theory, Distributed Artificial Intelligence and Middleware solutions. The purpose of the paper is not to eulogise any particular technology but to highlight the relevance of research in the areas of Distributed systems, Distributed Artificial Intelligence and Middleware and illustrate how they might co-evolve

Towards a contract-based interoperation model

Web Services-based solutions for interoperating processes are considered to be one of the most promising technologies for achieving truly interoperable functioning in open environments. In the last three years, the specification in particular of agreements between resource / service providers and consumers, as well as protocols for their negotiation have been proposed as a possible solution for managing the resulting computing systems. In this report, the state of the art in the area of contract-based web service applications is closely studied, identifying current limitations and possibilities. On the basis of this analysis, a general model for contract specification, negotiation, agreement, execution and management is introduced. Such a model has broad applicability both in electronic business integration and distributed knowledge management systems for decision support. Initial work presented here was completed in September 2005 and is published here as background for the European Commission funded project IST CONTRACT http://www.ist-contract.org/.Postprint (published version

The impact of network topology on trade in bartering networks: Devising and assessing network information propagation mechanisms

Resource allocation in distributed systems is an exciting area of research. Inherent properties in this environment, such as strategic users acting selfishly and the structure of the environment within which exchanges occur, are relevant challenges to study. This paper proposes a market–based resource allocation in a distributed environment. Our model has as it is objective the exploration of the effects of network structure in the allocation of performance together with mechanisms to improve the performance of the market. The proposed model, as well as mechanisms to maximize the allocation of objects/goods have been implemented and studied experimentally. The results obtained shows that topology affects the performance of the market. Using information propagation mechanisms clearly contributes to its improvement.Postprint (published version

Studying viable free markets in peer-to-peer file exchange applications without altruistic agents

File sharing networks are among the most popular applications of Peer-to-Peer (P2P) technology to date and have been widely studied in terms of the performance, behavior, topology and other properties. A persistent theme throughout this research has been the evidence that many P2P file sharing systems rely on the presence of altruistic users, who provide files, network capacity or some other goods without obvious personal gain to work and are potentially damaged by the presence of too many free-riders (users who consume resources but do not provide to others in return). In this paper we will explore the use of simple market mechanisms for P2P file sharing which function without the need of altruistic users considering the conditions under which such markets may be viable.Postprint (published version