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.

A Timed Colored Petri-Net-based Modelling for Contract Net Protocol with Temporal Aspects

Abstract: Contract Net Protocol (CNP) is a high level communication protocol. It is one of the most widely used in multi-agent system (MAS) to resolve decentralized task allocation problem. The main aim of the protocol is to facilitate contract negotiation between a manager agent and many contractor agents. A lot of works have been done for the verification of the protocol and its extensions, but there still lacks a formalism for representing temporal interaction aspects which are an essential parameter in the protocol modeling. This paper proposes to use Timed Colored Petri Nets (TCPN) to model correctly and formally this temporal dimension often defined as interaction duration and message deadlines. We will verify by means of simulation techniques and state space analysis important properties namely model correctness, deadline respect, absence of deadlocks and livelocks, absence of dead code, agent terminal states consistency, concurrency and validity. Keywords-Negotiation protocols; Contract net protocol; Multiagent systems; Timed Colored Petri Nets.

Trust-Enhanced Self-configuration for Organic Computing Systems

Abstract: Organic Computing (OC) enhances computer systems by postulating life-like properties to enable a system to self-configure, self-heal, self-optimize and self-protect. It is a solution to reduce the complexity of systems but is based on a benevolence assumption that all parts of the system are reliable and interested to further the system goal. In open and heterogeneous systems, the benevolence assumption is unrealistic, since uncertainties about the participants' behavior have to be regarded. We propose trust as a concept to cope with these uncertainties. This paper presents a trust enhancement of the self-configuration algorithm based on the well-known Contract Net Protocol. This baseline algorithm can be used in a distributed system, i.e., multi-agent system, cloud computing or grid system, to equally distribute the load of services on the nodes. However, the trust enhancement of self-configuration assigns services with different importance levels to nodes so that more important services are assigned to more reliable nodes. Evaluations have been conducted to rate the effectiveness of the algorithm when nodes are failing, i.e., the reduction of failures of important services. The results show that our self-configuration algorithm increases the availability of important services by more than 12%. To our knowledge this is the first trust integrated self-configuration process that proposes to build reliable and robust heterogeneous distributed systems in a decentralized way.

A Quantitative Analysis of the Contract Net Protocol

Abstract: The Contract Net Protocol (CNP) [Smith, 1980] assigns a subtask to agents which are involved in multiagent problem solving. Although the logical aspects of the negotiation protocol have been analyzed, the properties of protocol dynamics remain unclear. This paper introduces our quantitative analysis of protocol dynamics which is essential for constructing continuous reaitime applications. We carried out a simulation which based on queueing theory to practice the purpose described above. Two kinds of agent, manager and contractor, exist within the simulation. Managers provide tasks to contractors which undertake them as follows: first, when a task arrives, the manager responsible for it announces it with a bidding deadline to all of contractors immediately; second, each contractor selects from all the announced tasks, the one that best matches its own standards, and bids for it; finally, the manager chooses the most appropriate bid, and awards it to that agent; a manager can make multiple announcements simultaneously while a contractor can bid for only one task at a time. Each manager and contractor has a evaluation function fi and gj, respectively. Manager i awards a bidder that achieves maxj []i(j)] and contractor j selects task that achieves max~Lqj(i)]. The .?i and gj is generated as a list containing the natural numbers from I to 100. The service time for a task and the bidding period is fixed at 1 and 0.1 respectively. We say managers or contractors are homogeneous when fix(J) = fib(J) gj, (i) = gj2(i), otherwise heterogeneous. The manager utility and the contractor utility is respectively calculated by _.L~, ~"~--’l ~"~-~=l/~(J), wherein c is the number

A multiagent approach for managing collaborative workflows in supply chains

Abstract: Due to sophisticated and frequently changing demands from customers, global competition and technological advances, the next generation advanced manufacturing technologies will rely on cooperation and collaboration of business partners to share costs, risks and expertise as no single company has all the expertise needed. To respond to these challenges, development of an effective scheme for managing collaborative workflows is required. In this paper, we propose a framework to achieve coherent and consistent workflows that can meet order requirements based on multi-agent systems (MAS). Scheduling collaborative workflow is a challenging problem due to the computational complexity involved, distributed architecture and dependency of different partners' workflows. We propose an approach that combines MAS, contract net protocol, workflow models and optimization theories. We have implemented a prototype system based on industrial standards, including FIPA and the Petri net workflow specification model. Our solution algorithm has been developed based on transformation of the workflow model to optimization models to find the solutions.

HNG: A Robust Architecture for Mobile Robots Systems

Abstract: Researchers in robotics agree that control architectures must be reactive, modular, standardized, reliable, and should allow the use of multiple functions In the last few years, the open challenges organized by the DARPA have shown that robustness can be obtained and that real autonomous systems can be built We conducted an analysis of several control architectures, and especially of those who had good performances in terms of reliability The purpose of this analysis was to select the best mechanisms in the available architectures and to build an architecture that would allow us to proceed to benchmarking and prototyping for perception, planning and control algorithms on real systems in difficult environments As a result, the Hybrid and Network-based Generic architecture HNG uses multiple processes, publish/subscribe communication mechanisms, and its control is based on contract net mechanisms Our preliminary tests show the potential of this approach