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Showing papers on "Multi-agent system published in 2002"


Book
12 Jun 2002
TL;DR: A multi-agent system is a distributed computing system with autonomous interacting intelligent agents that coordinate their actions so as to achieve its goal(s) jointly or competitively.
Abstract: The study of multi-agent systems (MAS) focuses on systems in which many intelligent agents interact with each other. These agents are considered to be autonomous entities such as software programs or robots. Their interactions can either be cooperative (for example as in an ant colony) or selfish (as in a free market economy). This book assumes only basic knowledge of algorithms and discrete maths, both of which are taught as standard in the first or second year of computer science degree programmes. A basic knowledge of artificial intelligence would useful to help understand some of the issues, but is not essential. The books main aims are: To introduce the student to the concept of agents and multi-agent systems, and the main applications for which they are appropriate To introduce the main issues surrounding the design of intelligent agents To introduce the main issues surrounding the design of a multi-agent society To introduce a number of typical applications for agent technology

4,042 citations


Proceedings ArticleDOI
15 Jul 2002
TL;DR: A reputation system that takes advantage, among other things, of social relations between agents to overcome the problem of scarce interaction in large multi-agent systems.
Abstract: The use of previous direct interactions is probably the best way to calculate a reputation but, unfortunately this information is not always available. This is especially true in large multi-agent systems where interaction is scarce. In this paper we present a reputation system that takes advantage, among other things, of social relations between agents to overcome this problem.

639 citations


Journal ArticleDOI
TL;DR: In this article, the authors present a trade-off strategy where multiple negotiation decision variables are traded-off against one another (e.g., paying a higher price in order to obtain an earlier delivery date or waiting longer to obtain a higher quality service).

566 citations


Journal ArticleDOI
TL;DR: Simulation results have demonstrated that this method is able to reach suboptimal target configurations, which are favorably compared with those obtained by a mathematical programming approach.
Abstract: This paper proposes a multi-agent approach to power system restoration. The proposed system consists of a number of bus agents (BAGS) and a single facilitator agent (FAG). BAG is developed to decide a suboptimal target configuration after a fault occurrence by interacting with other BAGS based on only locally available information, while FAG is to act as a manager in the decision process. The interaction of several simple agents leads to a dynamic system, allowing efficient approximation of a solution. Simulation results have demonstrated that this method is able to reach suboptimal target configurations, which are favorably compared with those obtained by a mathematical programming approach.

394 citations


Proceedings ArticleDOI
02 Jul 2002
TL;DR: This work describes Anthill, a framework to support the design, implementation and evaluation of P2P applications based on ideas such as multi-agent and evolutionary programming borrowed from CAS, and describes preliminary experiences with Anthill in implementing a file sharing application.
Abstract: Recent peer-to-peer (P2P) systems are characterized by decentralized control, large scale and extreme dynamism of their operating environment. As such, they can be seen as instances of complex adaptive systems (CAS) typically found in biological and social sciences. We describe Anthill, a framework to support the design, implementation and evaluation of P2P applications based on ideas such as multi-agent and evolutionary programming borrowed from CAS. An Anthill system consists of a dynamic network of peer nodes; societies of adaptive agents travel through this network, interacting with nodes and cooperating with other agents in order to solve complex problems. Anthill can be used to construct different classes of P2P services that exhibit resilience, adaptation and self-organization properties. We also describe preliminary experiences with Anthill in implementing a file sharing application.

373 citations


Proceedings ArticleDOI
15 Jul 2002
TL;DR: A method based on this idea, which is also used by well-known ranking algorithms, is proposed that uses only local information in order to extract reputation and it is able to adapt automatically to the topology of the network or graph.
Abstract: The problem of calculating a degree of reputation for agents acting as assistants to the members of an electronic community is discussed and a solution presented. Usual reputation mechanisms rely on feedback after interaction between agents. An alternative way to establish reputation is related with the position of each member of a community within the corresponding social network. We propose a method based on this idea, which is also used by well-known ranking algorithms, discuss its properties as well as experimental results and compare them to other reputation mechanisms for electronic communities supported by agents. The method proposed uses only local information in order to extract reputation and it is able to adapt automatically to the topology of the network or graph.

308 citations


Proceedings Article
01 Aug 2002
TL;DR: Focusing-on settings where side payments are not possible, it is shown that the mechanism design problem is NP-complete for deterministic mechanisms and if the authors allow randomized mechanisms, the mechanisms design problem becomes tractable.
Abstract: The aggregation of conflicting preferences is a central problem in multiagent systems. The key difficulty is that the agents may report their preferences insincerely. Mechanism design is the art of designing the rules of the game so that the agents are motivated to report their preferences truthfully and a (socially) desirable outcome is chosen. We propose an approach where a mechanism is automatically created for the preference aggregation setting at hand. This has several advantages, but the downside is that the mechanism design optimization problem needs to be solved anew each time. Focusing-on settings where side payments are not possible, we show that the mechanism design problem is NP-complete for deterministic mechanisms. This holds both for dominantstrategy implementation and for Bayes-Nash implementation. We then show that if we allow randomized mechanisms, the mechanism design problem becomes tractable. In other words, the coordinator can tackle the computational complexity introduced by its uncertainty the agents face additional uncertainty. This comes at no loss, and in some cases at a gain, in the (social) objective.

296 citations


Proceedings ArticleDOI
15 Jul 2002
TL;DR: The ROADMAP1 methodology is described, which extends Gaia with four improvements - formal models of knowledge and the environment, role hierarchies, explicit representation of social structures and relationships, and incorporation of dynamic changes.
Abstract: This paper is concerned with improving the software engineering of agent-based open systems. It critiques the existing Gaia methodology in the light of a motivating example of intelligent home networks. It describes the ROADMAP1 methodology, which extends Gaia with four improvements - formal models of knowledge and the environment, role hierarchies, explicit representation of social structures and relationships, and incorporation of dynamic changes.

283 citations


Book ChapterDOI
TL;DR: This paper presents a methodology named ADELFE, which is led by the Rational Unified Process but is devoted to software engineering of adaptive multi-agent systems, and guarantees that the software is developed according to the AMAS theory.
Abstract: Adaptive software is used in situations where either the environment is unpredictable or the system is open. This paper presents a methodology named ADELFE, which is led by the Rational Unified Process (RUP) but is devoted to software engineering of adaptive multi-agent systems. ADELFE guarantees that the software is developed according to the AMAS theory1. We focus this presentation on the additions of ADELFE regarding the three first core workflows of the RUP. Therefore, during the requirements phase, the environment of the studied system must be defined and characterized. Then, in the analysis phase, the engineer is guided to decide to use adaptive multi-agent technology and to identify the agents through the system and the environment models. Finally, the design workflow of ADELFE must provide the cooperative agent?s model and helps the developer to define the local agents? behavior. We illustrate the methodology by applying it to a case study: a timetable design.

245 citations


Book ChapterDOI
11 Nov 2002
TL;DR: The MOISE+ model - described here through a soccer team example - intends to be a step in this direction since the organization is seen under three points of view: structural, functional, and deontic.
Abstract: A Multiagent System (MAS) that explicitly represents its organization normally focuses either on the functioning or the structure of this organization. However, addressing both aspects is a prolific approach when one wants to design or describe a MAS organization. The problem is to define these aspects in such a way that they can be both assembled in a single coherent specification. The MOISE+ model - described here through a soccer team example - intends to be a step in this direction since the organization is seen under three points of view: structural, functional, and deontic.

244 citations


Journal ArticleDOI
TL;DR: A behavior language is a reactive planning language, based on the Oz Project language Hap, designed specifically for authoring believable agents-characters that express rich personality, and that, in this case, play roles in an interactive story called Facade.
Abstract: A behavior language is a reactive planning language, based on the Oz Project language Hap, designed specifically for authoring believable agents-characters that express rich personality, and that, in this case, play roles in an interactive story called Facade.

Patent
08 Aug 2002
TL;DR: In this paper, an apparatus and method for iterative problem solving that uses intelligent agents such as a brain agent, profile agent, personality agent, a knowledge agent and an error handling agent to interpret questions posed by a user and to provide responses back to the user.
Abstract: An apparatus and method for iterative problem solving that uses intelligent agents such as a brain agent, a profile agent, a personality agent, a knowledge agent and an error handling agent to interpret questions posed by a user and to provide responses back to the user. The apparatus and method may further use a mood agent, a visual agent, sound agent, a tactile agent, and a smell/taste agent and various connectors to external data sources to interpret questions and provide responses back to the user. The apparatus and method may further parse questions in a conceptual manner. The apparatus and method may further optimize its system performance by evolving with and reacting to user interactions.

Journal ArticleDOI
TL;DR: The aims in this article are to briefly summarize the key concepts of decision theory and game theory, to discuss how these tools are being applied in agent systems research, and to introduce this special issue of Autonomous Agents and Multi-Agent Systems by reviewing the papers that appear.
Abstract: In the last few years, there has been increasing interest from the agent community in the use of techniques from decision theory and game theory Our aims in this article are firstly to briefly summarize the key concepts of decision theory and game theory, secondly to discuss how these tools are being applied in agent systems research, and finally to introduce this special issue of Autonomous Agents and Multi-Agent Systems by reviewing the papers that appear

Journal ArticleDOI
TL;DR: This article proposes a simulation-based DCF scheme designed to let rational agents form coalitions in dynamic environments that is well suited for applications of ubiquitous and mobile computing.
Abstract: Dynamic coalition formation (DCF) promises to be well suited for applications of ubiquitous and mobile computing. This article proposes a simulation-based DCF scheme designed to let rational agents form coalitions in dynamic environments.

Proceedings ArticleDOI
28 Jul 2002
TL;DR: This investigation of reinforcement learning techniques for the learning of coordination in cooperative multi-agent systems focuses on a novel action selection strategy for Q-learning (Watkins 1989), and demonstrates empirically that this extension causes the agents to converge almost always to the optimal joint action even in these difficult cases.
Abstract: We report on an investigation of reinforcement learning techniques for the learning of coordination in cooperative multi-agent systems. Specifically, we focus on a novel action selection strategy for Q-learning (Watkins 1989). The new technique is applicable to scenarios where mutual observation of actions is not possible.To date, reinforcement learning approaches for such independent agents did not guarantee convergence to the optimal joint action in scenarios with high miscoordination costs. We improve on previous results (Claus & Boutilier 1998) by demonstrating empirically that our extension causes the agents to converge almost always to the optimal joint action even in these difficult cases.

28 Jul 2002
TL;DR: In this paper, the authors proposed a method to solve the problem of the problem.xvii and X.viii.xiv.x.v.vii.
Abstract: xvii

Book
Yang Xiang1
01 Aug 2002
TL;DR: This paper presents a meta-model for distributed multi-agent inference of Bayesian networks and describes the architecture of these networks in terms of junction trees and cluster graphs.
Abstract: This 2002 book investigates the opportunities in building intelligent decision support systems offered by multi-agent distributed probabilistic reasoning. Probabilistic reasoning with graphical models, also known as Bayesian networks or belief networks, has become increasingly an active field of research and practice in artificial intelligence, operations research and statistics. The success of this technique in modeling intelligent decision support systems under the centralized and single-agent paradigm has been striking. Yang Xiang extends graphical dependence models to the distributed and multi-agent paradigm. He identifies the major technical challenges involved in such an endeavor and presents the results. The framework developed in the book allows distributed representation of uncertain knowledge on a large and complex environment embedded in multiple cooperative agents, and effective, exact and distributed probabilistic inference.

Book Chapter
01 Jan 2002
TL;DR: This chapter proposes a method, develops abstract models, and presents first results of a modeling tool used to understand the dynamics of natural and renewable resources and their management in the field of simulating societies in interaction with their environment.
Abstract: For several years now, a field of research on simulating societies in interaction with their environment has been taking shape Methods such as multi-agent systems (MAS) can be used to create virtual societies The effects of interactions among different behaviors on resource dynamics and associated feedback are simulated Modelers use such methods to create computer representations of dynamics observed in the field [] After using operational research methods to identify the solution to a given problem, researchers turned to ways of representing a stakeholder's strategic and tactical decisions through expert systems or simulation methods Then, multiagent systems provided a new tool for the modeling of complexity and particularly the modeling of collective decisions Our team' has been using MAS in several ways 1 We developed abstract models, also called artificial societies that help to understand the generic properties of interacting processes We mainly developed models on non-merchant exchanges and reputation, models on economic tools for the regulation of economic exchanges and models on spatial dynamics 2 We also developed applied models to understand the dynamics of natural and renewable resources and their management 3 We developed a modeling tool (CORMAS, common-pool resources and multi-agent systems) 4 We also worked on defining the possible uses for these MAS tools within the very wide framework of collective decision support The objective of this chapter is to propose a method and present our first results (Resume d'auteur)

Proceedings ArticleDOI
15 Jul 2002
TL;DR: MABLE is a language for the design and automatic verification of multi-agent systems, and makes use of the spin model checker to automatically verify the truth or falsity of claims.
Abstract: MABLE is a language for the design and automatic verification of multi-agent systems. MABLE is essentially a conventional imperative programming language, enriched by constructs from the agent-oriented programming paradigm. A MABLE system contains a number of agents, programmed using the MABLE imperative programming language. Agents in MABLE have a mental state consisting of beliefs, desires and intentions. Agents communicate using request and inform performatives, in the style of the fipa agent communication language. MABLE systems may be augmented by the addition of formal claims about the system, expressed using a quantified, linear temporal belief-desire-intention logic. MABLE has been fully implemented, and makes use of the spin model checker to automatically verify the truth or falsity of claims.

Journal ArticleDOI
TL;DR: A solution approach for the efficient use of network capacity that takes into consideration driver's personal preferences for mode, routing and departure/arrival time is suggested.
Abstract: Developing real-time approaches to manage roadway network congestion over time and space is a difficult problem. While many approaches to solving networking problems have been posed, the roadway routing problem is fundamentally different in that route choice behavior rests solely with the flow entities (drivers). The challenge is to find and implement solutions that achieve an efficient reallocation of network capacity over time and space without seriously violating any individual user’s preferences for mode, routing, departure, and/or arrival time. This paper proposes a solution approach based on cooperative multi-agent-based principled negotiation between agents that represent network managers, information service providers, and drivers equipped with route guidance systems. It is demonstrated that the cooperative, multi-agent approach is a natural extension of the National ITS Architecture. Furthermore, the approach is highly scalable and adaptable to a variety of networks and user populations.

Journal ArticleDOI
TL;DR: This paper addresses a basic two-route scenario with different types of information and studies the impact of it using simulations, pointing out that the nature of the information very much influences the potential benefits of the ATIS.
Abstract: Since advanced traveler information systems (ATIS) have been introduced, their potential benefits as well as their drawbacks have been discussed controversially. This will continue as long as the drivers’ reactions upon current or even predictive information about the traffic situation are not known. Thus, traffic models that also consider this feedback are necessary. In this paper, we address a basic two-route scenario with different types of information and study the impact of it using simulations. The road users are modeled as agents, a natural and promising approach to describe them. Different ways of generating current information are tested. It is pointed out that the nature of the information very much influences the potential benefits of the ATIS.

Journal ArticleDOI
TL;DR: This paper describes and compares integrated TRYS and TRYS autonomous agents, two multiagent systems that perform decision support for real-time traffic management in the urban motorway network around Barcelona, and develops some conclusions respecting the general applicability of multiagent architectures for intelligent traffic management.
Abstract: This paper reports our experiences with agent-based architectures for intelligent traffic management systems. We describe and compare integrated TRYS and TRYS autonomous agents, two multiagent systems that perform decision support for real-time traffic management in the urban motorway network around Barcelona. Both systems draw upon traffic management agents that use similar knowledge-based reasoning techniques in order to deal with local traffic problems. Still, the former achieves agent coordination based on a traditional centralized mechanism, while in the latter coordination emerges upon the lateral interaction of autonomous traffic management agents. We evaluate the potentials and drawbacks of both multiagent architectures for the domain, and develop some conclusions respecting the general applicability of multiagent architectures for intelligent traffic management.

DOI
01 Jan 2002
TL;DR: This paper presents a framework for one- to-many negotiation by means of conducting a number of concurrent coordinated one-to-one negotiations, and outlines two levels of strategies that can be exercised on two levels, the individual negotiation level, and the coordination level.
Abstract: Negotiation is a process in which two or more parties with different criteria, constraints, and preferences, jointly reach an agreement on the terms of a transaction. Many current automated negotiation systems support one-to-one negotiation. One-to-many negotiation has been mostly automated using various kinds of auction mechanisms, which have a number of limitations such as the lack of the ability to perform two-way communication of offers and counteroffers. Moreover, in auctions, there is no way of exercising different negotiation strategies with different opponents. Even though auction-based online trading is suitable for many applications, there are some in which there is a need for such greater flexibility. There has been a significant body of work towards sophisticated one-to-one automated negotiation. In this paper, we present a framework for one-to-many negotiation by means of conducting a number of concurrent coordinated one-to-one negotiations. In our framework, a number of agents, all working on behalf of one party, negotiate individually with other parties. After each negotiation cycle, these agents report back to a coordinating agent that evaluates how well each agent has done, and issues new instructions accordingly. Each individual agent conducts reasoning by using constraint-based techniques. We outline two levels of strategies that can be exercised on two levels, the individual negotiation level, and the coordination level. We also show that our one-to-many negotiation architecture can be directly used to support many-to-many negotiations. In our prototype Intelligent Trading Agency (ITA), agents autonomously negotiate multi- attribute terms of transactions in an e-commerce environment tested with a personal computer trading scenario.

Journal ArticleDOI
10 Dec 2002
TL;DR: This work describes a general approach for dynamic and intelligent reconfiguration of real-time distributed control systems that utilizes the IEC 61499 function block model, based on object-oriented and agent-based methods.
Abstract: We describe a general approach for dynamic and intelligent reconfiguration of real-time distributed control systems that utilizes the IEC 61499 function block model. This work is central to the development of distributed intelligent control systems that are inherently adaptable and dynamically reconfigurable. The approach that is used takes advantage of distributed artificial intelligence at the planning and control levels to achieve significantly shorter up-front commissioning times as well as significantly more responsiveness to change. This approach is based on object-oriented and agent-based methods, and aims at overcoming the difficulties associated with managing real-time reconfiguration of an intelligent manufacturing system.

Journal ArticleDOI
TL;DR: Security issues that need to be addressed before multi-agent systems in general, and mobile agents in particular, can be a viable solution for a broad range of commercial applications are considered.
Abstract: The agent paradigm is currently attracting much research. A mobile agent is a particular type of agent with the ability to migrate from one host to another, where it can resume its execution. We consider security issues that need to be addressed before multi-agent systems in general, and mobile agents in particular, can be a viable solution for a broad range of commercial applications. This is done by considering the implications of the characteristics given to agents and the general properties of open multi-agent systems. The paper then looks in some more detail at security technology and methods applicable to mobile agent systems.

Proceedings Article
07 May 2002
TL;DR: This paper investigates the synergy between a web-based research paper recommender system and an ontology containing information automatically extracted from departmental databases available on the web, and the ontology's interest-acquisition problem.
Abstract: Recommender systems learn about user preferences over time, automatically finding things of similar interest. This reduces the burden of creating explicit queries. Recommender systems do, however, suffer from cold-start problems where no initial information is available early on upon which to base recommendations. Semantic knowledge structures, such as ontologies, can provide valuable domain knowledge and user information. However, acquiring such knowledge and keeping it up to date is not a trivial task and user interests are particularly difficult to acquire and maintain. This paper investigates the synergy between a web-based research paper recommender system and an ontology containing information automatically extracted from departmental databases available on the web. The ontology is used to address the recommender systems cold-start problem. The recommender system addresses the ontology's interest-acquisition problem. An empirical evaluation of this approach is conducted and the performance of the integrated systems measured.

Journal ArticleDOI
TL;DR: A compositional method is presented for the verification of multi-agent systems, and shows which combinations of pro-activeness and reactiveness in a specific type of information agents lead to a successful cooperation.
Abstract: A compositional method is presented for the verification of multi-agent systems. The advantages of the method are the well-structuredness of the proofs and the reusability of parts of these proofs in relation to reuse of components. The method is illustrated for an example multi-agent system, consisting of co-operative information gathering agents. This application of the verification method results in a formal analysis of pro-activeness and reactiveness of agents, and shows which combinations of pro-activeness and reactiveness in a specific type of information agents lead to a successful cooperation.

Journal ArticleDOI
TL;DR: The article introduces an architecture, the MASST system architecture, which supports dynamic information and knowledge exchange among the cooperating agents, and uses a dynamic blackboard as an interagent communication paradigm to facilitate factual data, business rule, and command exchange between cooperating MASST agents.
Abstract: A distributed problem solving system can be characterized as a group of individual cooperating agents running to solve common problems. As dynamic application domains continue to grow in scale and complexity, it becomes more difficult to control the purposeful behavior of agents, especially when unexpected events may occur. This article presents an information and knowledge exchange framework to support distributed problem solving. From the application viewpoint the article concentrates on the stock trading domain; however, many presented solutions can be extended to other dynamic domains. It addresses two important issues: how individual agents should be interconnected so that their resources are efficiently used and their goals accomplished effectively; and how information and knowledge transfer should take place among the agents to allow them to respond successfully to user requests and unexpected external situations. The article introduces an architecture, the MASST system architecture, which supports dynamic information and knowledge exchange among the cooperating agents. The architecture uses a dynamic blackboard as an interagent communication paradigm to facilitate factual data, business rule, and command exchange between cooperating MASST agents. The critical components of the MASST architecture have been implemented and tested in the stock trading domain, and have proven to be a viable solution for distributed problem solving based on cooperating agents.

Journal ArticleDOI
01 Sep 2002
TL;DR: A new hybrid modeling framework is also described, a hybrid of the two: hierarchical and heterarchical frameworks that uses intelligent agents to function in a cooperative manner so as to accomplish individual, as well as cell-wide and system-wide objectives.
Abstract: Existing modeling frameworks for manufacturing system control can be classified into hierarchical, heterarchical, and hybrid control frameworks. The main drawbacks of existing frameworks are discussed in this paper. A new hybrid modeling framework is also described. It is a hybrid of the two: hierarchical and heterarchical frameworks. In this proposed framework, entities (e.g., parts) and resources (e.g., material handling devices, machines, cells, departments) are modeled as holonic structures that use intelligent agents to function in a cooperative manner so as to accomplish individual, as well as cell-wide and system-wide objectives. To overcome the structural rigidity and lack of flexibility, negotiation mechanisms for real-time task allocation are used. Lower-level holons may autonomously make their negotiations within the boundary conditions that the higher-level holons set. Horizontal, as well as vertical decisions, are made between various levels of controllers, and these are explicitly captured in the model.

Proceedings ArticleDOI
15 Jul 2002
TL;DR: This paper examines the use of transparent agent replication, a technique in which the replicates of agents appear and act as one entity thus avoiding an increase in system complexity and minimizing additional system loads.
Abstract: Despite the considerable efforts spent on developing multi-agent systems the actual number of deployed systems is surprisingly small. One of the reasons for the significant gap between developed and deployed systems is their brittleness.The absence of centralized control components makes it difficult to detect and treat failures of individual agents thus risking fault-propagation that can seriously impact the performance of the system. Using redundancy by replication of individual agents within a multi-agent system is one possible approach for improving fault-tolerance. Unfortunately the introduction of replicates leads to increased complexity and system load. In this paper we examine the use of transparent agent replication, a technique in which the replicates of agents appear and act as one entity thus avoiding an increase in system complexity and minimizing additional system loads. The paper defines transparent agent replication and identifies the key challenges in using it. Special attention is given to the inter-agent communication, read/write consistency, resource locking, resource synthesis and state synchronization. An implementation of the transparent agent replication for the FIPA-OS framework is presented and the results of testing it within a real-world multi-agent system are shown.