Showing papers on "Contract Net Protocol published in 2004"
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TL;DR: A task allocation protocol that is efficient in time and tolerates crash failures in multi-agent systems and optimizes the length of the negotiation processes among agents is presented.
Abstract: This article presents a task allocation protocol that is efficient in time and tolerates crash failures in multi-agent systems. The protocol is an extension of the negotiation protocol defined by Smith and Davis [25, 26] for task allocation. Our extension of the Contract Net Protocol (1) enables an agent to manage several negotiation processes in parallel; (2) optimizes the length of the negotiation processes among agents; (3) reduces the contractors' decommitment situations; (4) enables the detection of failures of an agent participating in a negotiation process and prevents a negotiation process with blocked agents.
149 citations
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TL;DR: The importance of coordination in supply chain is emphasised and a general architecture of agile supply chain management is presented based on a multi-agent theory, in which the supply network is managed by a set of intelligent agents for one or more activities.
Abstract: In a worldwide network of suppliers, factories, warehouses, distribution centres and retailers, the supply chain plays a very important role in the acquisition, transformation, and delivery of raw materials and products. One of the most important characteristics of agile supply chain is the ability to reconfigure dynamically and quickly according to demand changes in the market. In this paper, concepts and characteristics of an agile supply chain are discussed and the agile supply chain is regarded as one of the pivotal technologies of agile manufacture based on dynamic alliance. Also, the importance of coordination in supply chain is emphasised and a general architecture of agile supply chain management is presented based on a multi-agent theory, in which the supply chain is managed by a set of intelligent agents for one or more activities. The supply chain management system functions are to coordinate its agents. Agent functionalities and responsibilities are defined respectively, and a contract net protocol joint with case-based reasoning for coordination and an algorithm for task allocation is presented.
90 citations
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TL;DR: This paper describes a negotiation protocol proposed for inter-agent cooperation in a multi-agent system that was developed for optimisation and dynamic integrated scheduling within steel production and evaluated in terms of stability and utility measures used to evaluate the robustness of the steel production processes in the presence of real-time events.
65 citations
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TL;DR: A practical collaboration framework for supply chain management wherein multi-agent systems form dynamic information networks and co-ordinate their production and order planning according to synchronised estimation of market demands.
Abstract: One of the main research issues in supply chain management is to improve the global efficiency of supply chains. However, the improvement efforts often fail because supply chains are complex, are subject to frequent changes, and collaboration and information sharing in the supply chains are often unfeasible. This paper presents a practical collaboration framework for supply chain management wherein multi-agent systems form dynamic information networks and co-ordinate their production and order planning according to synchronised estimation of market demands. In the framework, agents employ an iterative relaxation contract net protocol to find the most desirable suppliers by using data envelopment analysis. Furthermore, the chain of buyers and suppliers, from the end markets to raw material suppliers, form dynamic information networks for synchronised planning. This paper presents an agent-based dynamic information network for supply chain management and discusses the associated pros and cons.
57 citations
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TL;DR: The main results include: a multi-agent model and a collaboration process to form commitment graphs in HMS based on contract net protocol, a procedure to convert commitment graph to collaborative Petri net (CPN), and feasible conditions and collaborative algorithms to award contracts in HMSbased on CPNs.
41 citations
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14 Mar 2004TL;DR: Two further extensions to CNP by the ideas of Threshold and Degree of Availability (DoA) are made, which might become another feasible way to increase system effectiveness and efficiency.
Abstract: Being easily understood and implemented for resource allocation or task assignment, FIPA Contract Net Protocol (CNP) has been widely applied to kinds of Multi-Agent System (MAS). Basing on a typical extension to the original CNP, which was named as Contract Net with Confirmation Protocol (CNCP), this paper made two further extensions to CNP by the ideas of Threshold and Degree of Availability (DoA). CNCP enabled the agents to make proposals or accept offers in a continuous time, but it also increased the risk of getting sub-optimal deal or nothing for individual agent. Our research is just aiming at relieving this risk. The idea of threshold comes from the fact that: no matter how much proposals one agent sent out, it will get only one task to do at last. By setting a proper threshold, we can save many unnecessary computational costs in making or evaluating proposals. The concept of DoA is derived from the principle of Maximum Expected-Utility (MEU). With this concept, one agent will evaluate proposals not only by the required costs, it also takes the DoA of a participant as an important factor in choosing its best deal, so initiators can act in a more rational way. We also presented an under-consideration idea "Deadline", which might become another feasible way to increase system effectiveness and efficiency.
35 citations
31 Dec 2004
TL;DR: A revised and simpler core semantics is suggested for many of the FIPA ACL speech acts, using the same belief-intention style of logic, although the underlying ideas are not dependent on this detail.
Abstract: Multi-agent conversations are built upon two components: agent communication languages (ACLs) that specify the individual messages that can be exchanged and interaction protocols (IPs) that specify the sequences in which these message can be arranged. Although informative, the semantic definition proposed for the most standard ACL (FIPA 1997) is complicated and contentious, while published IPs tend to be ambiguous, incomplete, and unverified with respect to message semantics. As a case study to clarify and help rectify these problems, we have investigated verification of the contract net protocol when its messages are presumed to be expressed in FIPA ACL. In order to help both informal comprehension and formal verification we separate several concerns. We suggest a revised and simpler core semantics for many of the FIPA ACL speech acts, using the same belief-intention style of logic, although the underlying ideas are not dependent on this detail. An extended form of propositional dynamic logic and statecharts is used to express IPs. States are interpreted using mutual beliefs and intention, and properties such as termination and consistency of joint beliefs are shown.
33 citations
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19 Jul 2004
TL;DR: This work uses a Contract Net protocol for comparing various strategies for trusting other agents and introduces three classes of trustiers: a random trustiers, a statistical trustier, and a cognitive trustier.
Abstract: We use a Contract Net protocol for comparing various strategies for trusting other agents. We introduce three classes of trustiers: a random trustier, a statistical trustier, and a cognitive trustier.
28 citations
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TL;DR: This model, which is based on the negotiation of social commitments, results in highly flexible protocols that support agent heterogeneity while abiding by software engineering practices, and exemplifies the specification of protocols using the contract net protocol.
Abstract: Building conversation protocols has traditionally been an art more than a science, as their construction is often guided by designers’ intuition rather than by a principled approach. In this paper we present a model for building conversation protocols using inference principles that allow the computational specification and verification of message sequencing and turn-taking. This model, which is based on the negotiation of social commitments, results in highly flexible protocols that support agent heterogeneity while abiding by software engineering practices. We exemplify the specification of protocols using the contract net protocol, a common interaction protocol from the multiagent literature.
27 citations
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TL;DR: A new approach based on a modular architecture is presented, where a protocol is no longer monolithic but a composition of modules called micrc-protocols, which improves modularity and reusability in interaction protocol engineering.
Abstract: Protocols or part of protocols are frequently reused through projects if they are sufficiently generic. For instance, the Contract Net protocol can be used verbatim or in other protocols such as the supply chain management. This reusability might be difficult to do due to the lack of reusability in current interaction protocol formalisms. In this paper, we present a new approach based on a modular architecture. A protocol is no longer monolithic but a composition of modules called micrc-protocols. This approach improves modularity and reusability in interaction protocol engineering. We apply this idea to the example of supply chain management.
25 citations
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19 Jul 2004
TL;DR: This paper proposes a novel market-based communication protocol, which governs the aggregate behaviour of individual agents and subsequent emergent properties of the system, and shows that by promoting diversity within the agent population it is possible to avoid deadlock or "tie" conditions, which otherwise have to be solved arbitrarily by the deadlocked agents.
Abstract: One focus of multi-agent systems research is the notion that complex outcomes or behaviours may be arrived at through the interaction of agents. However, it is still an open question as to how agents in a complex system form coalitions or modules, and how these coalitions self-organize into hierarchies. In this paper, we begin to address this question by investigating agent collaboration in the context of a high-level pattern recognition task. We propose a novel market-based communication protocol, which governs the aggregate behaviour of individual agents and subsequent emergent properties of the system. Based on the Contract Net Protocol, individual agents bid to join coalitions (or solutions to a given problem). An important contribution of this study is the analysis of the role heterogeneous agents play in the formation of coalitions. Using a simple model, we show that by promoting diversity within the agent population it is possible to avoid deadlock or "tie" conditions, which otherwise have to be solved arbitrarily by the deadlocked agents.
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TL;DR: The algorithm of dynamic contract net protocol, which is proposed to apply the situation in which the environment and the capabilities of each agent can dynamically change with time, is given.
Abstract: This paper improves the classical contract net protocol, and according to swarm intelligence a dynamic contract net protocol is proposed to apply the situation in which the environment and the capabilities of each agent can dynamically change with time.This paper gives the algorithm of dynamic contract net protocol. Many experiments on the multi-agent platform MAGE(Multi-AGent Environment) show the advantages of dynamic contract net protocol.
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26 Aug 2004TL;DR: A three-layer system structure composed of decision customer layer, decision core layer and decision resource layer is designed to implement the communication and cooperation with each intelligent agent in system.
Abstract: Enterprise marketing has the characteristics of importance and distribution, so a distributed intelligent decision support system is needed to support the marketing decision. On the basis of sufficiently analyzing the necessity and feasibility for using the multi-intelligent-agent technology to develop the distributed marketing decision support system, this paper designs a three-layer system structure composed of decision customer layer, decision core layer and decision resource layer. Then the article discusses the information flow between the intelligent agents of the system, and puts forward to utilize the communication mechanism based on messages and the cooperation mechanism based on the contract net protocol to implement the communication and cooperation with each intelligent agent in system.
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20 Oct 2004TL;DR: In this paper, the authors propose a modelling and simulation framework based on a discrete-event formalism for supporting the development process of multi-agent systems; from specification to implementation, which allows for the incremental refinement of agents and experimental set-ups while providing rigorous observation facilities.
Abstract: The deployment of multi-agent systems demands for justified confidence into their functioning, both with respect to correctness of behaviour and with respect to timeliness thereof. Depending on the stage of the development process different mechanisms and abstractions are needed to facilitate the evaluation of interacting agents. We propose a modelling and simulation framework based on a discrete-event formalism for supporting the development process of multi-agent systems; from specification to implementation. The framework allows for the incremental refinement of agents and experimental set-ups while providing rigorous observation facilities. The benefit of using discrete-event modelling and simulation techniques for evaluating agents is illustrated using a simple example based on the Contract Net Protocol.
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26 Aug 2004TL;DR: The multi-agent cooperative pursuit algorithm is proposed based on the extended contract net protocol, which has shown the feasibility and validity of the given algorithm.
Abstract: This paper mainly discusses multi-agent pursuit-evasion game: one team of agents pursues another team of agents. Contract net protocol is extended, including improvement of alliance decision and permissively dynamic alliance. The multi-agent cooperative pursuit algorithm is proposed based on the extended contract net protocol. Simulation results have shown the feasibility and validity of the given algorithm.
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TL;DR: The Bayesian decision making is introduced to extend the contract net protocol, and a multi-agent negotiation system architecture is constructed and it is proved that the learning model reduces the information exchange times between agents and increases their utility.
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TL;DR: The fault tolerant property of CPN is analyzed to characterize tolerable resource failures in MAS based on the concept of critical path and a structural decomposition method to test the liveness condition is proposed.
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01 Dec 2004
TL;DR: A cooperative system that applies the concept of HMS to implement a distributed control system for automatic warehouse and FMS that is able to reconfigure the re-order points, increase the system fault tolerances, and provide the dynamic rescheduling.
Abstract: This paper presents a flexible manufacturing system (FMS) that cooperated with the holonic manufacturing system (HMS) with automatic material handling devices via industrial networks. The HMS is described as an intelligent manufacturing system that employs multi-agent system with negotiation protocols. The traditional HMS's negotiation protocol usually used the contract net protocol (CPN) and multi-level contract net protocol (MCPN). This paper develops a cooperative system that applies the concept of HMS to implement a distributed control system for automatic warehouse and FMS. Results from simulation indicated that our approach is able to improve the overall system flexibility. The system is able to reconfigure the re-order points, increase the system fault tolerances, and provide the dynamic rescheduling.
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26 Jul 2004
TL;DR: A framework to execute contract net protocol based on Web Services technologies and a Petri net model to analyze the contract net negotiation results is proposed.
Abstract: Contract net protocol can be implemented by exploiting the Web Service technologies. However, the lack of a process model in contract net protocol to capture the interactions between the bidder and manager agents makes it difficult to analyze the feasibility of the resulting contracts. We proposed a framework to execute contract net protocol based on Web Services technologies and a Petri net model to analyze the contract net negotiation results.
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04 May 2004
TL;DR: This paper focuses on development of a framework to model HMS by extending the contract net protocol with timed Petri net model, and results include a nominal collaborative PetriNet agent model for HMS.
Abstract: Holonic manufacturing system (HMS) is a paradigm based on multi-agent system theory that allows fast reconfiguration of available resources to cope with changing product demands in highly uncertain manufacturing environment. The advantage and flexibility offered by HMS poses new challenges and complexities in modeling and design of production control systems. For example, HMS is largely based on multi-agent system (MAS). Contract net protocol is a well-known negotiation and task distribution mechanism for MAS. However, production processes cannot be modeled with contract net protocol. Instead, most existing literatures model production processes based on Petri net theory. The lack of integration among different modeling tools makes it deficient to apply existing tools to model, planning and control HMS. A promising solution to model HMS is to combine the flexibility and robustness of multi-agent theory with the modeling and analytical power of Petri net. This paper focuses on development of a framework to model HMS by extending the contract net protocol with timed Petri net model. The main results include: (1) a nominal collaborative Petri net (CPN) agent model for HMS. (2) Liveness conditions for (CPN) and (3) a resource unavailability model to capture the effects of resource failures. (4) Fault tolerant conditions to test whether a certain type of resource failures are allowed based on Petri net agent model of HMS and (5) a collaborative algorithm to test the feasibility of a solution.
01 Jan 2004
TL;DR: The outcome of this project is to enable the successful execution of the commitment framework by agents by integrating the CM reasoning framework with JACK Intelligent Agent Language for automatic protocol generation and execution.
Abstract: Traditional approaches for software agents to represent interaction protocols in open systems, such as FSM, Petri-Nets and AUML result in rigid and heavily constrained protocols. This is due to the fact that the resulting protocols contain only legal sequences of actions. However, in an open and uncertain environment, protocols need to be flexible so as to handle different scenarios that might occur. The development of the Commitment Machine framework allows for flexible specification of protocols. It defines a high level concept of using commitments to govern the execution of agent actions. This is done by attaching meaningful content to each protocol state and action, instead of representing them as just state transitions or message exchange. Previous work represent and implement the commitment machine framework using the Event Calculus, by supplying the specified commitment machine protocol to an event calculus planner, which then works out the alternative protocol runs. However, the generated protocol runs are only available for reference but not for execution. This is because the protocol runs are not integrated with the agents involved. The outcome of this project is to enable the successful execution of the commitment framework by agents. This is done by integrating the CM reasoning framework with JACK Intelligent Agent Language for automatic protocol generation and execution. Two approaches were taken for the implementation and compared: JACK Agents method and JACK Teams Method. As a result of the comparison, JACK Teams prove to be a better method of implementation as its framework is more suitable for the realization of commitment machine protocols.
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01 Jan 2004TL;DR: A hybrid architecture and negotiation protocol for the dynamic scheduling of assembling systems based on multi-agent systems that combines the advantage of both hierarchical structure and distributed structure is proposed.
Abstract: Reconfigurable Assembly System (RAS) is designed at the outset for rapid change in structure, in order to quickly respond to the needs of market in terms of product variety and quantity. This paper is focus on the architecture of RAS. We propose a hybrid architecture and negotiation protocol for the dynamic scheduling of assembling systems. The architecture is based on multi-agent systems. This architecture combines the advantage of both hierarchical structure and distributed structure. A global management coordinates the whole system and every agent is highly autonomous. Otherwise, we introduce the agent specification. The well-known Contract Net Protocol has been adapted as the coordination model. The purpose of this protocol is to dynamically assign operation to the resources of the assembly system to realize system reconfiguration.
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06 Jul 2004
TL;DR: This work presents a flexible cell controller based on the multi-agent approach that resides in the total distribution of the scheduling and control functions and support of temporal and precedence constraints between tasks during scheduling process.
Abstract: This work presents a flexible cell controller based on the multi-agent approach. The main goal of the approach resides in the total distribution of the scheduling and control functions and support of temporal and precedence constraints between tasks during scheduling process. Contract Net protocol was the protocol adopted for scheduling and rescheduling process. An implementation of the proposed architecture is discussed.
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TL;DR: This paper discusses the implementation of Contract Net protocol in a number of shared data space models, beginning with LINDA, and followed by several of its more secure variants, and proposes the combination of Scope (a variant of LINDA) and access control attributes as the most appropriate model to be used as the mechanism in implementing CNP in the share data space communication model.
Abstract: Coordination is essential in distributed computing, which involves a group of loosely coupled agents cooperating in order to solve problems in a decentralised fashion. One of the popular approaches of coordination is the generative tuple space based communication, where agents interact via a shared data space. This paper discusses the implementation of Contract Net protocol (CNP) in a number of shared data space models, beginning with LINDA, and followed by several of its more secure variants. And finally, taking into account the importance of secure conversation in the process of task contracting, we propose the combination of Scope (a variant of LINDA) and access control attributes as the most appropriate model to be used as the mechanism in implementing CNP in the shared data space communication model. Apart from its tagging ability to limit visibilities and streaming property, the other significant advantages offered by Scope is its dynamicity (due to the scope-based operations), which is particularly useful in contracting several related tasks, where agents’ visibilities can be tailored (widened or limited) according to need. Incorporating attributes in the model provides a more secure contracting, without losing the flexibility offered by Scope.
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TL;DR: The Agent technology of the distribution artificial intelligence is adopted to suggest CAPP and production scheduling integration model based on Multi-Agent System(MAS) and this model is Dynamic Open Level/Layer(DOLL) control structure.
Abstract: The Agent technology of the distribution artificial intelligence is adopted to suggest CAPP and production scheduling integration model based on Multi-Agent System(MAS). This model is Dynamic Open Level/Layer(DOLL) control structure. The Contract Net protocol and active blackboard controller methods are adopted to realize information interaction and system execution. The prototype system based on this model is set up under the network environ so as to make the process planning and production scheduling Agent structure become the independent model which can better carry out the consultation feedback information. The scheduling process is simulated. The simulation results indicate that the system model suggested and the framework realization are correct and an effective way to solve the problem of scheduling bottleneck.
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28 Sep 2004TL;DR: The major discussed aspects cover the approach itself, agent-based architecture of the system "KSNet", architecture of an adaptive agent for on-the-fly problem solving, modified contract net protocol for agents' negotiation and a case study.
Abstract: *The paper describes an agent-based Knowledge Source Network (KSNet-) approach to coalition operation management and its implementation in a form of a decision support system (DSS) "KSNet". Multiagent systems suit well in the area of coalition operations that are based on temporary alliances of distributed autonomous parties. The major discussed aspects cover the approach itself, agent-based architecture of the system "KSNet", architecture of an adaptive agent for on-the-fly problem solving, modified contract net protocol for agents' negotiation and a case study.
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01 Jan 2004
TL;DR: In this article, an agent-based CAPP and PPC integrated architecture under network is proposed to overcome the rigidity of conventional hierarchical structures and to introduce new integrated architectures that are able to adapt to a dynamic environment, at same time the agent technology and self-organized method of holonic manufacturing have been used in attempts to resolve scheduling problem, a bidding mechanism based on Contract Net protocol is proposed as a key solution component.
Abstract: Manufacturing scheduling is a difficult problem, particularly when it takes place in an open and dynamic environment. In this paper Agent-based CAPP and PPC integrated architecture under network is proposed. The objective is to overcome the rigidity of conventional hierarchical structures and to introduce new integrated architectures that are able to adapt to a dynamic environment, at same time the agent technology and self-organized method of holonic manufacturing have been used in attempts to resolve scheduling problem, a bidding mechanism based on Contract Net protocol is proposed as a key solution component. Our approach is to combine a bidding mechanism based on Contract Net protocol with a mediation mechanism based on Mediator architecture, for dynamic manufacturing scheduling and rescheduling.
01 Jan 2004
TL;DR: The Extended Contract Net Protocol (ECNP) is introduced, and multi-agent cooperative pursuit algorithm is pmpased based on Extended Net protocol and Simulations are shown.
Abstract: are common sense for pursuers. This paper mainly discusses multi-agent pursuit-evasion The paper is organized as follows. In Section 2, the game: one team of agents Punus another team Of agents. problem description of multi-agent pursuit-evasion game is Contract Net Protocol is extended, including improvement of given, section 3, coopemtion mechanism based on alliance decision and permissively dynamic The Extended Contract Net Protocol (ECNP) is introduced, and multi-agent cooperative pursuit algorithm is pmpased based on Extended Net protocol. then in Section 4 multi-agent cooperative pursuit algorithm have shown the feasibility and validity oftbe given based on ECNF' is proposed. Simulations are shown in Section 5. Section 6 contains the conclusion of this paper.