Contract Net Protocol

About: Contract Net Protocol is a research topic. Over the lifetime, 606 publications have been published within this topic receiving 13729 citations.

Dynamic manufacturing scheduling using both functional and resource related agents

Abstract: Manufacturing scheduling is a difficult problem, particularly when it takes place in an open and dynamic environment. Agent-based technology has recently been used in attempts to resolve this problem. A bidding mechanism based on Contract Net protocol is often proposed as a key solution component. Our approach is to use both functional and physical resource related agents, and combine a bidding mechanism based on Contract Net protocol with a mediation mechanism based on Mediator architecture for realizing dynamic manufacturing scheduling and rescheduling. A machine-centered scheduling mechanism and related concepts and mechanisms are described, and a prototype implementation is presented.

Electronic contracts with primary and sponsored roles

Abstract: Computer-based methods and systems are provided for constructing, deploying, executing and managing the performance of electronic contract based service applications across multiple business entities. In this context, the electronic service contract includes information to be used for configuration and enforcement not just by the primary parties to the contract, but also by other parties referred to herein as sponsored roles in the contract. At least a portion of the contract may be monitored, enforced or managed by at least one of the sponsored roles. In one aspect of the invention, a computer-based electronic business service system includes: (1) a contract builder; (2) a contract deployment component; (3) one or more measurement systems; (4) a violation detection system; and (5) a management system. Generally, the contract builder component provides the mechanism for defining and pricing the contract, checking the validity of the contract and a repository for storing the completed contracts. The deployment system is responsible for configuring the (run-time) system in order to meet one or a set of contracts. The measurement system maintains information on the current system configuration, and run-time information on the metrics that are part of the contract. The violation detection system is responsible for comparing measured parameters against the thresholds defined in the contract and notifying the management system. Upon receipt of a notification, the management system will then issue appropriate actions to correct the problem, as specified in the contract.

Time-bound negotiation framework for electronic commerce agents

Abstract: For efficient and informative coordination of agents especially in electronic commerce environment, a time-bound agent negotiation framework is proposed utilizing a time-based commitment scheme. By attaching commitment duration to agent messages, the traditional contract net protocol is extended to a time-bound negotiation framework (TBNF). The proposed negotiation framework has a new message type which allows for parties to agree upon the extension of a commitment duration, and a novel commitment concept in the form of negative commitment. The semantics of the messages with the commitment duration are interpreted, and then the three typical negotiation protocols are formally defined and compared — nothing-guaranteed protocol, acceptance-guaranteed protocol , and finite-time guarantee protocol — which can be incorporated into TBNF. The TBNF should provide a background for efficient and effective electronic commerce negotiation while accommodating each agent's adaptive negotiation strategy.

AgenTalk: Coordination Protocol Description for Multiagent Systems.

Abstract: In multiagent systems, achieving coordination among autonomous agents is a major problem. Generally, a high-level protocol needs to be designed to achieve effective coordination. In the field of distributed artificial intelligence, protocols for achieving coordination have been proposed, such as the contract net protocol for task allocation (Smith 1980), and the multistage negotiation protocol for resource allocation under global constraints (Conry et al. 1991). These protocols have been further customized to suit various application domains. In addition, as software agents proliferate, demand for customized protocols will increase. In order to facilitate the development of multiagent coordination protocols, we designed a new language called AgenTalk. AgenTalk is not meant to be a forreal specification language; rather it is meant to be a programming language capable of implementing protocols and agents behaving according to the protocols. Its design policies are as follows. Explicit state representation of a protocol: An extended finite state machine which allows variables is used as a basis to describe coordination protocols. We call the representation of this state machine a script. Using this model, states of a protocol are explicitly defined, and actions of an agent can easily be defined for each state. Agent Program Application-specific Scdpts II l

The eager bidder problem: a fundamental problem of DAI and selected solutions

Abstract: The contract net protocol is a widely used protocol in DAI, as it proved to be a flexible and low communication interaction protocol for task assignment. It is however not clear in which manner agents participating in a contract net should allocate their resources if a large number of contract net protocols is performed concurrently. If the agent allocates too many resources too early, e.g. when making a bid, it may not get any bid accepted and resources have been allocated while other negotiations have come to an end and it is no longer able to make bids for them. If it allocates resources too late, e.g. after being awarded the contract, it may have made bids for more tasks than its resources allow for, possibly all being accepted and resulting in commitments that cannot be kept. We call this dilemma the Eager Bidder Problem. Apart from resource allocation this problem is of further importance as it constitutes the "dual" problem to engaging in multiple simultaneous first-price sealed-bid auctions.We present an ad hoc solution and two more complex strategies for solving this problem. Furthermore, we introduce a new method based on a statistical approach. We describe these mechanisms and how they deal with the concept of commitment at different levels. We conclude with criteria for the decision which of these mechanisms is best selected for a given problem domain.