The control of tasks in traditional distributed systems is a well researched field for which many solutions exist. These solutions exploit well defined parent-child relationships given in distributed systems; but they are not applicable in mobile agent systems, since no similar natural relationships between agents exist. Thus new mechanisms have to be developed. In this paper, we present an efficient control mechanism for mobile agents. It is based on the tracking method of AgentTracer and agent shadow, and we combine this tracking method with the energy concept. In the tracking mechanism, an artificial relationship between agents and the AgentTracer is defined. The AgentTracer has many entries for all the agents that are created in its area. Each entry records the current location of the dependent agent. Removing an entry at AgentTracer implies that the dependent agent is declared an orphan and eventually be terminated. In an extension of the basic mechanism we additionally allow the AgentTracer to be mobile.
Migrating workflow is an effective resolution to solve the problems of incomplete specification of business process and frequent changes of environment in workflow management community. Communication mechanism between different instances is one of the most important components to enable effective negotiation and cooperation in an autonomous alliance. However, existing communication schemes are not suitable for the dynamic and prompt self-organization of migrating instance alliance. In this paper, a reliable asynchronous communication model based on existing forwarding proxy and mailbox methods is provided to deal with such problems. The model captures the primary features on configuration and task execution of migrating workflow and balances between reliability and performance of the system. A series of algorithms are also presented to support reliable and asynchronous communication, efficient location tracking and timely proxy update. Moreover, original simulations show that the model can ensure reliable inter-instances communication, and keep overheads at reasonably low.
Based on the workflow patterns describing controlling features of the flow, this paper brings forward a workflow model based on workflow patterns and gives a method, in which workflow patterns are mapped to workflow pattern components firstly, and then constructs the workflow management system based on pattern components.
In multi-agent system, the learning of actions selected by each agent results in poor cooperation, at the same time the conventional reinforcement learning requires a large computation cost because every agent must learn separately. A novel multi-agent cooperative learning model (MCLM) and a multi-agent cooperative learning algorithm (MCLA) are presented to solve these problems. In MCLM, the agents have the ability to learn together, thus observing one another's actions to decide individual action strategy. Based on this model, trying to improve the applicability and efficacy of reinforcement learning algorithms, MCLA is introduced. In MCLA, an evaluating method based on long-time reward is proposed, in which the reward gradually converge at a stable value by constant interaction with environment and payments from it. A series of simulations are provided to demonstrate the practical values and performance of the proposed algorithm in solving hunter-prey problem
In the mobile agent system, a mobile agent has its life cycle, and its life state may change time after time. In order to improve the mobile agent management during its life cycle, this paper presents a mobile agent life state management model. This model keeps the records of all mobile agents life state changes occurred during its whole life cycle. This paper not only gives the agent life state log structure and its storage method, but also discussed the procedures for the log storing, searching, verifying and analyzing. Application examples show that life state management model can improve mobile agent system management evidently
In the resource-constrained workflow, a task is usually decomposed into a set of dependent subtasks. Since resources are limited, the task decomposition and planning should be optimized according to the specific executing environment. Based on the software component concepts, in this paper, a task is defined as a set of dependent task units, and the subtasks are clips of a task, in which all of the task units can be executed in a single limited resource. This paper presents a task decomposition and planning model for the resources-constrained workflow environment, by which the task decomposition and planning can be abstracted to a combinatorial optimization problem whose objective is to minimize executing and communicating overheads. In order to solve this problem, a discrete particle swarm optimization algorithm is proposed and the simulation experiments prove the effectiveness of the algorithm.
An efficient K-shortest paths routing algorithm for computer networks is presented. The Algorithm is based on enhancements to currently used link-state routing algorithms such as OSPF, which is only focusing on finding the shortest path route by Dijkstra algorithm. The desire effect to achieve is mainly through the use of K-shortest paths algorithm, which has been implemented successfully in some fields like traffic engineering. The correctness of this Algorithm is discussed as long as the comparison with OSPF.
Migrating workflow is a new workflow management pattern that migrating instance migrates in workplaces and completes one or more workflow tasks. The workflow task execution machine which is installed on the workplace has the responsibility of receiving the task delegation of migrating instance and completing one or more workflow tasks according to the task logic of delegation and the service rule in the local space, by referring the workflow resource and workflow service in the background work machine network. In this paper we discuss the workflow task execution model and propose a task execution scheduling algorithm. The installing of workflow task execution machine is propitious to improve the flexibility of workflow service and the security of workplace. It also can lightweight the workflow instance.
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