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

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

An analysis of paperclip arbitrage

While bartering is arguably the world's oldest form of trade there are still many instances where it surprises us. One such case is the remarkable story of Kyle MacDonald who, by means of a sequence of bartering exchanges between July 2005 and July 2006, managed to trade a small red paperclip for a full sized house in the town of Kipling Saskatchewan. Although there are many factors to consider in this achievement, his feat raises basic questions about the nature of the trades made and to what extent they are repeatable by others. Furthermore, it raises issues as to whether such events could occur in Agent–based Electronic Environments – and under what conditions. In this paper we provide an intuitive model for the type of trading environment experienced Kyle and study its consequences. In particular the work is focused on understanding whether such trading phenomena require altruistic agents to be present in the environment and under what conditions agents can reach their individual goals. Results cover both the case of a singlePostprint (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

Implementation considerations of an expert system to assess stream water quality management

The main goal of STREAMES (STream REAch Management, an Expert System) prototype is to assist to the water managers to evaluate human altered streams, via point and non-point sources and magnitudes of nutrient, deciding the best strategy in front of them. This technical report explains how the system is composed, interrelated, treating in depth about architectural and technological aspects. Our system is an environmental system. It is a system concerning on environmental domain, concretely on rivers ecosystem

Implementation considerations of an expert system to assess stream water quality management

The main goal of STREAMES (STream REAch Management, an Expert System) prototype is to assist to the water managers to evaluate human altered streams, via point and non-point sources and magnitudes of nutrient, deciding the best strategy in front of them. This technical report explains how the system is composed, interrelated, treating in depth about architectural and technological aspects. Our system is an environmental system. It is a system concerning on environmental domain, concretely on rivers ecosystem

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

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

An analysis of paperclip arbitrage

While bartering is arguably the world's oldest form of trade there are still many instances where it surprises us. One such case is the remarkable story of Kyle MacDonald who, by means of a sequence of bartering exchanges between July 2005 and July 2006, managed to trade a small red paperclip for a full sized house in the town of Kipling Saskatchewan. Although there are many factors to consider in this achievement, his feat raises basic questions about the nature of the trades made and to what extent they are repeatable by others. Furthermore, it raises issues as to whether such events could occur in Agent–based Electronic Environments – and under what conditions. In this paper we provide an intuitive model for the type of trading environment experienced Kyle and study its consequences. In particular the work is focused on understanding whether such trading phenomena require altruistic agents to be present in the environment and under what conditions agents can reach their individual goals. Results cover both the case of a singl