Showing papers on "Contract Net Protocol published in 2016"

A self-adaptation scheme for workflow management in multi-agent systems

Abstract: Business processes, operational environment, variability of resources and user needs may change from time to time. An effective workflow management software system must be able to accommodate these changes. The ability to dynamically adapt to changes is a key success factor for workflow management systems. Holonic multi-agent systems (HMS) provide a flexible and reconfigurable architecture to accommodate changes based on dynamic organization and collaboration of autonomous agents. Although HMS provides a potential architecture to accommodate changes, the dynamic organization formed in HMS poses a challenge in the development of a new software development methodology to dynamically compose the services and adapt to changes as needed. This motivates us to study and propose a methodology to design self-adaptive software systems based on the HMS architecture. In this paper, we formulate a workflow adaptation problem (WAP) and propose an interaction mechanism based on contract net protocol (CNP) to find a solution to WAP to compose the services based on HMS. The interaction mechanism relies on a service publication and discovery scheme to find a set of task agents and a set of actor agents to compose the required services in HMS. We propose a viable self-adaptation scheme to reconfigure the agents and the composed services based on cooperation of agents in HMS to accommodate the changes in workflow and capabilities of actors. We propose architecture for our design methodology and present an application scenario to illustrate our idea.

Multi-agent-based hierarchical collaborative scheduling in re-entrant manufacturing systems

Abstract: Production scheduling problems in re-entrant manufacturing systems are complex due to their features of large-scale complexity, unbalanced workload and dynamic uncertainty. The aim of this paper is thus to develop an effective way of formulating production schedules for designing RMSs. First, a multi-agent-based hierarchical collaborative system consisting of a system layer, a machine layer, and a material handling device layer is developed to improve the efficiency of RMSs. The objective of the system layer is to maximise the total processing profit, and the objective of the machine layer is to determine the winning bid. Second, a contract net protocol scheduling algorithm is applied to solve capacity planning problems for key machine groups in the system layer. Third, a generalised partial global planning-contract net collaborative mechanism is adopted to allocate tasks to machines within each machine group in the machine layer. Finally, the performance of the proposed approach is validated through a ca...

Equivalence class verification of the contract net protocol-extension

Abstract: The contract net protocol is a task allocation protocol that facilitates negotiation between bidders and an auctioneer in a multi-agent system to form a contract. The contract net protocol-extension (CNP-ext) allows the bidders to interact with more than one auctioneer concurrently, and to update their bids until a bid is granted. This introduces flexibility and ensures better selection of a bid. In earlier work, we modelled the CNP-ext with coloured petri nets and showed that it terminates correctly. We also analysed the terminal states and proved that the agents have consistent beliefs at the end of negotiations. Lastly, we showed how the number of terminal states and channel bounds are related to the number of bidders. However, due to state space explosion, our results were restricted to five bidders. As all bidders are considered identical, symmetries exist in the state space. Hence, we decided to tackle this problem using equivalence classes. In this paper, after first presenting an introduction to the CNP-ext, we present a substantial revision to our CNP-ext model and an intentionally didactic description of its operation. Then, we use equivalence classes to analyse the protocol and, importantly, present a proof that our equivalence specification is consistent. Using this technique, we are able to extend the verification results to twenty-four bidders.

Allocating Social Goals Using the Contract Net Protocol in Online Multi-agent Planning

Abstract: Centralised planning systems generally assign goals to agents during the search for a solution to a planning problem. In a distributed multi-agent setting, this would constrain the autonomy of the agents, and violate their privacy. Thus, by using task allocation protocols, the agents themselves can compete to decide who will take each goal, then later plan individually provided coordination mechanisms are in place, giving a higher degree of autonomy and privacy during the planning process. In this paper, we propose the use of a contract net protocol mechanism to allocate social goals in multi-agent planning. Our contributions are an algorithm for determining a bid, and several bid evaluation criteria. We also define some heuristics that can be used as bids. In our algorithm, agents expand social goals using their plan library in order to collect information and formulate their bid. We also show the results of experiments in a multi-agent planning domain in order to evaluate our heuristics.

On applying DisCSP for scheduling in holonic systems

Abstract: This paper presents a coordination mechanism for solving the scheduling problem in holonic systems. The proposed approach is based on a combination between the method of distributed constraint satisfaction problem and the contract net protocol. After presenting the coordination scheme, a Coloured Petri net model is introduced. This allowed more simulation experiments to be carried out that revealed conclusions on the usefulness of the proposed method.

The Command Decision Method of Multiple UUV Cooperative Task Assignment Based on Contract Net Protocol@@@The Command Decision Method of Multiple UUV Cooperative Task Assignment Based on Contract Net Protocol

Abstract: With the help of multiple UCAV cooperative task control model, the mathematical model of multiple UUV cooperative task control is made. Variables related to decision are broken into goals, guidelines and programs levels by Analytical Hierarchy Process (AHP), on this basis; the command decision of multiple UUV task assignment is achieved. The correctness of task allocation algorithm is verified by case analysis. Time calculation formulas for a task assignment are given. The changes of overall effectiveness in the process of task allocation are analyzed, the time changes of each sub task allocation time in one task assignment are analyzed, the time changes of the number of tasks and platforms respectively fixed in task allocation are also discussed.

Multi-agent framework for cloud service composition

Abstract: Cloud service composition is required when single cloud service cannot satisfy all requirements of the user. Cloud service composition presents an efficient managerial, on-demand and scalable way to integrate computational resources (hardware, platform, and software). It includes several tasks such as discovery, selection, and deployment of the services. In this paper, an Agent based approach for cloud service negotiation is proposed. Agent based technology has hailed as a new paradigm for implementing software agents. Software agents are autonomous entities which act on behalf of user across open and distributed environments. A Multi Agent System for cloud service composition makes use of a market-oriented approach which would regulate demand and supply chain. This work involves creating service provider agents and consumer agents. The resources offered by the service providers are created as virtual machines in cloud that would be mapped to the consumers. The consumer agent gets the input from the user and finds the best service providers who satisfy the consumer's constraints. Consumer agent further establishes a negotiation between these service providers and purchases the cloud services for market favorable cost. The consumer and service provider agents communicate using Contract Net Protocol, which is a task-sharing protocol in multi-agent system. The workflow architecture of this framework involves interaction and negotiation of the consumer and service provider agents. Also, a mathematical model has been proposed to support market-driven approach in cloud commerce.

Task allocation method of manned/unmanned aerial vehicle formation based on extended CNP

Abstract: Aiming at the shortcomings of centralized and distributed task allocation methods, and combined with the characteristics of manned/unmanned aerial vehicle formation, task assignment method based on Contract Net Protocol (CNP) is proposed and the manned vehicle can be a node of the CNP task assignment structure. After the extension, the adaptation to the dynamic combat environment and the managing ability to the new threats of the UAV formation are improved. Simulation results show that static and dynamic task assignment methods based on CNP are excellent in time efficiency and assignment effect.

A MAS based energy-coordination by contract net protocol for connecting the production units of energy renewable based wind-photovoltaic energy storage system to Grid

Abstract: A multi-agent system based energy-coordination by contract net protocol (MAS-ECCNP) is designed for to efficiently connect production units of energy renewable based wind-photovoltaic energy storage system (PUER-WPESs) to Grid. The negotiation protocol is a two-level bidding mechanism based on the contract net protocol. In the energy-coordination process, the proposed system allows the agent to cooperate and coordinate their actions taking into account their self-constraints and objective control to solve the optimal distribution plan overall energy and by the using the improved particle swarm algorithm to achieve the maximum economic benefit on the basic of stable operation. The paper presents the overall system design, the models of agents of different equipment, and overall energy optimizing coordination algorithm. An example is given to discuss the behavioral characteristics of negotiation and communication process based agent to verify that the system designed in this paper can achieve effective coordination of energy. The method adopted by this system can improve the efficiency of the overall operation and the economic benefits of REPU-WPESs.

Negotiation model for knowledge management system using computational collective intelligence and ontology-based reasoning: case study of SONATRACH AVAL

Abstract: This paper presents an agent-based approach that facilitates knowledge management and decision making in maintenance field by enabling the collaboration and negotiation between experts in SONATRACH AVAL. The main objective of the suggested model is to treat the business rules with semantic errors, expert agents are asked to negotiate in order to accept or refuse a modification of rules. To do so, the expert manager can be represented by an intelligent agent that negotiates with experts (participants). We propose an interactive negotiation model utilising an extended version of the contract net protocol (CNP) and an ontology named OntoloG. The experimental results show that the developed computation collective intelligence approach is very interesting and efficient for expert collaboration in the well-known petroleum enterprise in Algeria (SONATRACH).

Resources provisioning within cloud federation

Abstract: A cloud provider provides, on-demand, physical computing resources to clients. It enables clients to improve their computing delivered resources in virtual machines. However, the cloud provider faces major problems impacting its correct operation. One of these problems is that a cloud provider cannot deliver more resources when it has not enough resources during peak hours. Another problem related to providers is their inability to satisfy all client's requirements. In order to increase the reliability and the availability of cloud providers resources, we have proposed a distributed approach based on Contract Net Protocol (CNP) to overcome the limited resources problem. We have proposed also an extension for Open Virtualization Format (OVF) standard to describe resources provisioning in cloud federation. This extension includes more information about the client, the provider identification and the quality of service. To prove the efficiency and the effectiveness of our approach, we have suggested a real case study illustrating how a client can interact with our approach for the provision of two-tier web application. In addition to that, we have implemented a prototype to evaluate the key idea presented in this paper through a set of experiments.

Research on mission planning technique of autonomous collaborative manipulation for multiple space robot

Abstract: The Multiple Space Robot (abbreviated as MSR) can complete complex space manipulation mission. Under the background of future development and application of MSR, this paper proposes a mission planning technique for MSR On-Orbit Servicing. Mission of MSR is modeled based on Temporal Constraint Network, and complex temporal relations between subtasks of the mission are embodied with this model. Aiming at solving the problem of subtasks assignment, a modified Contract Net Protocol is proposed based on the basic concept of Contract Net Protocol, with a strategy of subtasks grouping bidding and a strategy of load balancing.

Optimization of quality of service (QoS) parameters using Contract Net Protocol in Ubiquitous Computing

Abstract: To generate large-scale resource management, grid based computing play a crucial role. It represents various geographically dispersed computational resources, i.e. workstations, PCs, cluster, storage devices, and database as fused integrated system, which can play dual roles of synchronized resource donator and consumer in such distributed computation environment. Now a day, in ubiquitous environment the use of embedded devices and mobile has grown intensively, produces abundant data which need to be processed. But, as these ubiquitous devices have limited power in terms of bandwidth, CPU, battery, storage; these applications services require more powerful computational resources. To fulfill these requirements, Grid can act as promising computational services provider to ubiquitous computing application. In this paper, we represent a competitive model, describing the interaction between Grid computational resources as competing service provider whereas ubiquitous applications as consumer. We represent Contract Net Protocol model for such competitive environment for quality of service (QoS) offered by Grid Service Provider (GSP). We have also studied model for the same competitive environment based on equilibrium behavior under definite QoS provision and the stochastic demand. Our proposed model and performance results give out appropriate strategies for real-time grid environment.

A Synchronous CNP-Based Coordination Mechanism for Holonic Manufacturing Systems

Abstract: Our paper presents a new holonic coordination approach, which can be useful for the difficult case when more holons try to assign common resources. It is based on the Contract Net Protocol and this is combined with synchronous backtracking. The coordination scheme also implies an a priori established hierarchy of manager holons. The proposed method ensures a safe operation and was evaluated on a manufacturing scenario with four robots.