一个多Agent系统的构建框架--JAFMAS

一种基于Java的多Agent系统的构建框架JAFMAS,它提供一套机制以实现Agent之间的通信、交互和协调。     

基于Agent图的三级多Agent系统组织模型

多Agent系统的组织结构是Agent个体之间交互的框架。对分布式多Agent系统的组织方式、协作机制进行了简要讨论,提出了Agent域及Agent图的概念。根据不同Agent之间的地理位置和通信代价,由Agent个体、Agent组及Agent域三级组织结构形成一个Agent图,并借鉴计算机网络的分布式自适应路由选择策略进行多Agent系统的协作组织。分析表明,该模型具有高效、健壮、通信开销较小等优点。     

基于Agent组织的多UAV协调模型

无人驾驶飞机(UAV)系统的协调问题是UAV研究领域的一个重要问题。研究了适应于UAV系统的Agent结构模型以及组织模型,提出了一种基于Agent组织的多UAV协调模型并给出了其数学化表述,分析了多UAV协调模型中任务协调、角色协调以及动作协调等三个阶段,并对提出的模型进行了仿真。实验表明,模型具有较好的适应性和稳定性。     

Agent的组织承诺和小组承诺

基于Agent组织的多Agent问题求解对降低求解难度和求解复杂性有重要意义.对Agent组织的研究主要集中在组织模型、组织规则、组织结构以及组织的形成和演化等方面,需要从组织中Agent的各种思维属性及其相互关系加以扩展.分析和定义了Agent组织中Agent的内部承诺和社会承诺、小组承诺和组织承诺,研究了基于承诺的Agent组织的形成机制以及Agent组织中承诺的性质,从而推广了关于Agent组织的研究.     

一个基于JaVa的多Agent系统框架JAFMAS及其改进

介绍一种基于Java多Agent系统构造框架JAFMAS。该框架可为多Agent系统的开发者提供了一组可扩展的Java类,使得开发者将力量集中于Agent的具体功能细节而不必担心Agent的通信方法和行为协调机制。该文介绍了框架的体系结构和分布式环境下Agent间的通信方法和行为协调机制,同时对JAFMAS做了一些改进。     

基于组织的面向Agent 程序设计及其语言Oragent

当前,面向Agent程序设计在支持动态开放多Agent系统开发方面存在一系列的不足,如缺乏高层抽象、底层实现模型与高层设计模型相脱节、在支持系统动态性方面缺乏有效的运行机制和语言设施等.针对这些问题,提出一种基于组织的面向Agent程序设计方法.该方法将组织、Group、角色和Agent等高层抽象作为一阶实体,缩小了多Agent系统的设计模型与实现模型之间的概念鸿沟;借助于组织学中的机制——角色扮演机制、基于角色的交互——支持系统动态性的规约和实现,如Agent行为的动态组合、动态的交互等,基于该程序设计思想,设计了基于组织的面向Agent程序设计语言——Oragent,定义了其抽象语法和形式语义,并通过案例分析说明了如何基于该程序设计思想和Oragent语言来构造和实现动态而灵活的多Agent系统.     

基于自治Agent的入侵检测系统模型

利用自治Agent的良好特性，提出了一个基于自治多Agent入侵检测系统模型。讨论了结构中各组件的功能以及Agent系统中关键的通信机制问题，并分析了一个实例。     

一种基于BDI Agent的复杂系统设计建模方法

提出一种通过信念一愿望一意图(BDI)结构实现多Agent系统设计建模的方法．多Agent系统设计建模的目的是具体地模型化多Agent组织中承担不同组织职能的每一类Agent的结构，使其易于在现有的程序设计语言环境中实现，在该方法中，多Agent系统的设计建模需要建立三个模型：Agent模型、相互作用模型和相识者模型．Agent模型由信念、目标、计划三个基本子模型构成，这些子模型是根据分析阶段所获得的职能模型、协同工作过程模型以及领域本体来建立的，MAS系统中的每一Agent都是Agent模型中某一类Agent的一个实例．相互作用模型主要说明Agent之间的交互细节，如交互协议、交互语言、交互约束条件等．相识者模型说明每一类Agent的所有相识者及其属性，目前通过这一建模方法已在多智能体协同工作平台(MBOS)上开发出实际的应用系统“多智能体物资调配决策支持系统MAEDSS”。     

面向Agent的基本思想研究

提出面向Agem的基本思想是以社会学理论为原则构造和演化复杂软件系统。基于人的社会化、社会互动、社会组织理论论述了面向Agent关键抽象模型Agent、交互、组织的定义;基于社会变迁理论提出多Agent系统演化的目标是Agent和组织的自增长以满足需求的变化。从关键抽象模型和软件技术发展的三要素比较了面向Agent与面向对象的不同。     

一种基于正关系的多Agent协调算法

多Agent之间的协调(coordination)与协作(cooperation)已经成为多Agent系统(multiagent system,MAS)中的一个关键问题。这是因为MAS的主要研究目标之一就是使得多Agent的信念、意图、期望、行为达到协调甚至协作。在开放、动态的MAS环境下,具有不同目标的多个Agent必须对其资源的使用以及目标的实现进行协调[1,4]。例如,在出现资源冲突时,若没有很好的协调机制,就有可能出现死锁。而在另一种情况下,当单个Agent无法独立完成目标,需要其它Agent帮助时,则需要协作。本文提出了一种基于正关系的多Agent协调机制和协调算法。在该算法中,通过使用这种协调机制,Agent能委托或接受交互中的子计划,从而形成系统负载均衡和有效降低系统运行开销。     

Coordinating Agents in Organizations Using Social Commitments

One of the main challenges faced by the multi-agent community is to ensure the coordination of autonomous agents in open heterogeneous multi-agent systems. In order to coordinate their behaviour, the agents should be able to interact with each other. Social commitments have been used in recent years as an answer to the challenges of enabling heterogeneous agents to communicate and interact successfully. However, coordinating agents only by means of interaction models is difficult in open multi-agent systems, where possibly malevolent agents can enter at any time and violate the interaction rules. Agent organizations, institutions and normative systems have been used to control the way agents interact and behave. In this paper we try to bring together the two models of coordinating agents: commitment-based interaction and organizations. To this aim we describe how one can use social commitments to represent the expected behaviour of an agent playing a role in an organization. We thus make a first step towards a unified model of coordination in multi-agent systems: a definition of the expected behaviour of an agent using social commitments in both organizational and non-organizational contexts.     

基于层次图变换的多Agent组织结构动态重组机制

如何动态适应环境是基于组织计算的多Agent系统的关键研究内容之一.组织结构的动态重组为多Agent系统柔性地实现组织目标提供了有效途径.结合Agent组织结构特点,给出了一种描述组织结构的社会结构、角色指定和Agent协调的单根节点层次图模型.通过单根节点和层次化地维护组织结构内元素的拓扑关系,有效地降低了大规模Agent组织重组问题的复杂性;扩展DPO(double-pushout)代数图变换,形式定义了Agent组织结构的重组过程.单根节点层次图描述了重组过程中给定时刻的组织结构状态,图变换规则序列定义了组织结构的变化过程.Agent组织重组和图匹配算法实验结果表明,该层次图变换方法有效地刻画了多Agent组织动态重组过程,并支持图形化重组过程要素设计和大规模Agent组织的重组计算.     

A two-layered multi-agent reinforcement learning model and algorithm

Multi-agent reinforcement learning technologies are mainly investigated from two perspectives of the concurrence and the game theory. The former chiefly applies to cooperative multi-agent systems, while the latter usually applies to coordinated multi-agent systems. However, there exist such problems as the credit assignment and the multiple Nash equilibriums for agents with them. In this paper, we propose a new multi-agent reinforcement learning model and algorithm LMRL from a layer perspective. LMRL model is composed of an off-line training layer that employs a single agent reinforcement learning technology to acquire stationary strategy knowledge and an online interaction layer that employs a multi-agent reinforcement learning technology and the strategy knowledge that can be revised dynamically to interact with the environment. An agent with LMRL can improve its generalization capability, adaptability and coordination ability. Experiments show that the performance of LMRL can be better than those of a single agent reinforcement learning and Nash-Q.     

基于语义近似逼近技术的多代理协作

本体在多代理系统中起着重要的作用,它提供和定义了一个共享的语义词汇库。然而,在现实的多代理通讯的过程中,两个代理共享完全相同的语义词汇库是几乎不可能的。因为信息不完整以及本体的异构等特性,一个代理只能部分理解另外一个代理所拥有的本体内容,这使得代理间的通讯非常困难。本文就是探索利用近似逼近技术实现基于部分共享分布式本体的多代理通讯,从而实现多代理之间的协作查询。我们使用基于OWLweb本体语言的描述逻辑来描述分布式本体的近似查询技术。最终我们也开发了基于语义近似逼近方法的一个多代理协调查询系统。     

Communication infrastructure in distributed scheduling

The emergence of distributed artificial intelligent (DAI) introduced a new approach to solve scheduling problems by a set of scheduling systems that interact with each other in the problem-solving process. In this paper, we describe a communication infrastructure to handle connection and communication between distributed Internet scheduling systems for distributed applications. First, we present an agent model of distributed scheduling systems where agents can communicate and coordinate activities with each other via an agent communication language. Then, we define the syntax and semantics for the agent communication languages, and negotiation mechanism. Following that, we discuss the design and development of the prototype for the multi-agent scheduling systems. We conclude with a discussion of communication issues for heterogeneous agent-based scheduling systems to solve distributed scheduling problems.     

一种基于博弈论的多Agent交互模型

在开放的、动态的多Agent系统(MAS)中,交互是最基本的方面,具有各自利益的多个Agent必须对其目标、资源的使用进行协调.博弈论为协调和协作的研究奠定了坚实的数学基础,把博弈论与多Agent交互相结合是目前DAI研究的新发展方向.该文提出了一种基于博弈论的多Agent交互模型(GMAIM),应用于解决不完全信息的分布式环境下多人协商决策问题,实现了在会议调度系统(MSS)中的应用.     

Reflections on the Nature of Multi-Agent Coordination and Its Implications for an Agent Architecture

The development of enabling infrastructure for the next generation of multi-agent systems consisting of large numbers of agents and operating in open environments is one of the key challenges for the multi-agent community.Current infrastructure support does not materially assist in the development of sophisticated agent coordination strategies. It is the need for and the development of such a high-level support structure that will be the focus of this paper. A domain-independent (generic) agent architecture is proposed that wraps around an agent's problem-solving component in order to make problem solving responsive to real-time constraints, available network resources, and the need to coordinate—both in the large and small—with problem-solving activities of other agents. This architecture contains five components, local agent scheduling, multi-agent coordination, organizational design, detection and diagnosis, and on-line learning, that are designed to interact so that a range of different situation-specific coordination strategies can be implemented and adapted as the situation evolves. The presentation of this architecture is followed by a more detailed discussion on the interaction among these components and the research questions that need to be answered to understand the appropriateness of this architecture for the next generation of multi-agent systems.     

Evolutionary patterns of agent organizations

Problems approached by multi-agent systems are typically complex. It is usually difficult to know at system design stage how many agents need to be in the system, what each agent's role is, and how the agents should interact to get optimal performance out of the group. The aim of the testbed presented here is to investigate which kinds of multi-agent systems could be developed to solve ranges of problems, avoiding the need to reorganize the agents from scratch for each task. The agent organization process explored here is based on the agents' knowledge, and not on their tasks. This opens up a new approach for distributed artificial intelligence designers to have their domain organized before the allocation of tasks among agents. These kinds of organizations should be more robust for solving different problems related to the same knowledge. We define information oriented domains for that purpose. An evolutionary approach to the design of a multi-agent system is suggested. Our model is based on a cellular automaton whose rules of dynamics induce the formation of an organization of agents. Patterns of organization obtained empirically are presented. Our knowledge-based organization approach is analyzed both from theoretical and practical perspectives     

Using Domain-Independent Exception Handling Services to Enable Robust Open Multi-Agent Systems: The Case of Agent Death

This paper addresses a simple but critical question: how can we create robust multi-agent systems out of the often unreliable agents and infrastructures we can expect to find in open systems contexts? We propose an approach to this problem based on distinct exception handling (EH) services that enact coordination protocol-specific but domain-independent strategies to monitor agent systems for problems (‘exceptions’) and intervene when necessary to avoid or resolve them. The value of this approach is demonstrated for the ‘agent death’ exception in the Contract Net protocol; we show through simulation that the EH service approach provides substantially improved performance compared to existing approaches in a way that is appropriate for open multi-agent systems.     

Individual learning of coordination knowledge

Abstract. Social agents, both human and computational, inhabiting a world containing multiple active agents, need to coordinate their activities. This is because agents share resources, and without proper coordination or ‘rules of the road’, everybody will be interfering with the plans of others. As such, we need coordination schemes that allow agents to effectively achieve local goals without adversely affecting the problem-solving capabilities of other agents. Researchers in the field of Distributed Artificial Intelligence (DAI) have developed a variety of coordination schemes under different assumptions about agent capabilities and relationships. Whereas some of these researchers have been motivated by human cognitive biases, others have approached it as an engineering problem of designing the most effective coordination architecture or protocol. We evaluate individual and concurrent learning by multiple, autonomous agents as a means for acquiring coordination knowledge. We show that a uniform reinforcement learning algorithm suffices as a coordination mechanism in both cooperative and adversarial situations. Using a number of multi-agent learning scenarios with both tight and loose coupling between agents and with immediate as well as delayed feedback, we demonstrate that agents can consistently develop effective policies to coordinate their actions without explicit information sharing. We demonstrate the viabilityof using both the Q-learning algorithm and genetic algorithm based classifier systems with different pay-off schemes, namely the bucket brigade algorithm (BBA) and the profit sharing plan (PSP), for developing agent coordination on two different multi-agent domains. In addition, we show that a semi-random scheme for action selection is preferable to the more traditional fitness proportionate selection scheme used in classifier systems.