基于指向路径分次删剪的移动Agent通信算法

基于移动agent环境,在应用程序的开发时agent的移动为应用程序找到一种好的通信处理方式。因此通讯算法要面对更多的挑战,最主要的就是agent移动和消息传递之问的异步性而带来的通信不可靠问题。由于目前解决此类问题的算法和机制都有不足之处,本文就针对此类问题来介绍一种新的agent通信算法,即S-COMP算法,它综合了多种手段,主要有:集中同步、指向路径分次删剪、途经节点转发、Home寻址等,能够满足各种不同需求的agent的通信特点,既可以保证适应性和效率,同时也具有可靠性。     

ACP--一种基于局部邮区的移动agent通信算法

agent的迁移在位置透明性、通信可靠性以及迁移和执行的异步性等多方面对通信算法的设计提出了挑战,提出一种基于局部邮区的移动agent通信算法,通过在agent当前通信和迁移活动较集中的区域建立局部邮区来支持消息的高效传输,且通过对邮区迁移和消息发送的同步来保证通信的可靠性。此外,算法支持通信的位置透明性,对Home结点依赖少,对agent迁移不做限制,且具有较好的适应性和容错性。     

基于CORBA的移动agent通信模型的设计

移动agent技术是目前比较热门的分布式技术,其通信机制是其重要的组成部分.文中为了解决agent的运行平台和底层通信机制的异构性问题,专门针对移动终端为PDA而提出的基于CORBA的移动agent通信模型.该通信模型屏蔽了运行平台和底层通信机制,能够有效的解决移动agent的通信问题.     

基于移动Agent的数字水印技术

作为一种数字产品版权保护的新方法,数字水印技术越来越受到人们的关注.但是如何有效在大型网络中检测数字水印,仍然是一个具有挑战性的问题.本文提出了一种基于移动agent的数字水印模型,通过建立移动agent平台来实现水印的检测.     

基于组件技术的移动Agent网络中层管理器的设计

本文分析了基于SNMP网络管理中存在的问题,并在SNMP网络管理的基础上结合移动agent在网络管理中的优势,介绍了一种基于组件的移动agent网络中层管理器,目的是对网络进行实时有效和准确的管理,使网络为用户提供更好的服务。     

基于多邮箱的移动Agent通信算法

agent移动的可靠性、实时性是移动agent通信中的难点。该文在总结已有算法的基础上,引入多邮箱和主机Controller的概念,结合两者实现了一个高效、可靠的移动agent通信算法,能保证通信的可靠性和实时性,使得移动agent的迁移变得简单且完全自由。     

Agent推与拉通信模式性能比较临界条件及推模式算法

寻求一种稳定、位置透明的移动Agent通信策略,目前仍然是一个热门的研究课题.将推和拉两种消息传递的基本模式进行了详细分析,给出了两种模式性能比较的临界条件.该理论结果对无线网络中快速移动设备之间的消息传递同样具有借鉴意义.最后在基于邮箱的通信算法基础上,引入区域划分的思想,成功实现了推模式通信算法,算法能有效地进行移动Agent透明通信,大大降低了消息由邮箱到达Agent的时延,并降低了网络通信负载.     

Mogent系统的通信机制

移动agent技术是新型软件构件框架的基础技术之一,而通信机制是其重要的组成部分.该文 结合移动agent系统Mogent(mobile agent)平台的研制,在分析了agent的移动特性对通信机 制的影响后,提出并实现了一种用于Mogent平台的一套系统的解决方案.该方案主要包括移动 agent命名机制、移动agent寻址机制以及通信失效解决方法等,具有易于使用、效率高、可 靠性好等优点.     

基于蜂群算法的移动agent迁移策略研究*

旅行agent问题是一个复杂的组合优化问题,在于解决保证agent在不同主机间移动时如何根据任务情况规划路线,实现在完成任务时间最短的路线上迁移。采用进化算法的搜索求解具有启发性强、鲁棒性强的特点,但也面临着陷于局部最优解,导致agent在迁移过程中整体任务完成效率降低等问题。提出了一种基于蜂群算法的agent迁移模型,将agent划分为侦察、引领和跟随三种角色,agent通过彼此间的信息互换,在群体迁移的过程中同时实施新路径的发现和调整。实验结果表明,该算法可以很好地实现目标寻径效率,与经典蚁群算法相比     

基于移动agent的网格环境的安全技术研究

本文阐述了网格环境的特点、安全需求和移动agent.针对移动agent引入到网格环境中的应用需求所产生的安全问题进行研究,提出了基于移动agent的网格环境的安全体系结构模型.并用一次网格作业执行过程对该模型进行安全性分析,采用数字签名技术保护移动agent的通信过程,实现了单点登录,为多个管理域、多种安全策略,以及主体动态变化的条件下提供网格统一的安全方案.     

Reliable Communication for Highly Mobile Agents

The provision of a reliable communication infrastructure for mobile agents is still an open research issue. The challenge to reliability we address in this work does not come from the possibility of faults, but rather from the mere presence of mobility, which complicates the problem of ensuring the delivery of information even in a fault-free network. For instance, the asynchronous nature of message passing and agent migration may cause situations where messages forever chase a mobile agent that moves frequently from one host to another. Current solutions rely on conventional technologies that either do not provide a solution for the aforementioned problem, because they were not designed with mobility in mind, or enforce continuous connectivity with the message source, which in many cases defeats the very purpose of using mobile agents.In this paper, we propose an algorithm that guarantees delivery to highly mobile agents using a technique similar to a distributed snapshot. A number of enhancements to this basic idea are discussed, which limit the scope of message delivery by allowing dynamic creation of the connectivity graph. Notably, the very structure of our algorithm makes it amenable not only to guarantee message delivery to a specific mobile agent, but also to provide multicast communication to a group of agents, which constitutes another open problem in research on mobile agents. After presenting our algorithm and its properties, we discuss its implementability by analyzing the requirements on the underlying mobile agent platform, and argue about its applicability.     

一种改进的移动Agent通信算法

如何实现远程Agent通信的位置透明性，保证消息不会因为目标Agent迁移而丢失，一直是移动Agent通信所面临的难题，在现有的很多移动Agent系统中都没有得到解决，作者在Mogent系统中提出的通信算法初步实现了通信的位置透明和可靠的消息传输，该文在原有处的基础上提出了一种改进的适于多种迁移和通信模式的移动Agent通信算法，进一步减少了Agent的地址注册开销和迁移受到的限制，并给出了一种避免地址欺骗攻击的解决方案。     

基于Agent的网络安全系统协同控制研究

提出一种基于代理的协同控制架构,并且描述了该协同控制架构、代理与系统之间的通信协议、系统之间的报文交换协议、加密认证策略、控制中心的保护、协同响应等。该框架不仅能从底层提供了智能协同控制的功能,而且有利于采用统一的加密认证策略,使系统的安全性得到加强。同时系统的消息定义和协同控制具有可扩充性特点,增强了框架的适应能力。     

A scalable group communication mechanism for mobile agents

Many multi-agent applications based on mobile agents require message propagation among group of agents. A fast and scalable group communication mechanism can considerably improve performance of these applications. Unfortunately, most of the existing approaches do not scale well and disseminate messages slowly when the number of agents grows.In this paper, we propose Sama, a new group communication mechanism, to speed up message delivery for a group of mobile agents on a heterogeneous internetwork. The main contribution of Sama is distribution and parallelization of message propagation in an efficient way to achieve scalability and high-speed of message delivery to group members. Sama uses message dispatcher objects (MDOs), which are stationary agents on each host, to propagate messages concurrently. The proposed mechanism is independent of agent locations and transparently delivers messages to the group using constant number of remote messages. It also transparently recovers from host failures. We also present a Hop-Ring protocol that considerably improves the performance of message dissemination in Sama. Our experimental results show that message propagation in Sama is significantly fast compared to the previously proposed methods.     

基于注意力消息共享的多智能体强化学习

通信是非全知环境中多智能体间实现有效合作的重要途径,当智能体数量较多时,通信过程会产生冗余消息。为有效处理通信消息,提出一种基于注意力消息共享的多智能体强化学习算法AMSAC。首先,在智能体间搭建用于有效沟通的消息共享网络,智能体通过消息读取和写入完成信息共享,解决智能体在非全知、任务复杂场景下缺乏沟通的问题;其次,在消息共享网络中,通过注意力消息共享机制对通信消息进行自适应处理,有侧重地处理来自不同智能体的消息,解决较大规模多智能体系统在通信过程中无法有效识别消息并利用的问题;然后,在集中式Critic网络中,使用Native Critic依据时序差分（TD）优势策略梯度更新Actor网络参数,使智能体的动作价值得到有效评判;最后,在执行期间,智能体分布式Actor网络根据自身观测和消息共享网络的信息进行决策。在星际争霸Ⅱ多智能体挑战赛（SMAC）环境中进行实验,结果表明,与朴素Actor?Critic （Native AC）、博弈抽象通信（GA?Comm）等多智能体强化学习方法相比,AMSAC在四个不同场景下的平均胜率提升了4 ~ 32个百分点。AMSAC的注意力消息共享机制为处理多智能体系统中智能体间的通信消息提供了合理方案,在交通枢纽控制和无人机协同领域都具备广泛的应用前景。     

一种改进的移动Agent通信算法

通信机制是移动Agent技术研究的重要课题,目前提出的多种Agent通信机制都尚未满足要求或存在缺陷,该文结合多种传统的Agent通信机制,提出了一种改进的移动Agent通信算法,实现了通信的位置透明性、高可靠性、高效性,极大地减少了迁移受到的限制和迁移引起的地址注册(或更改)开销。该算法在网络主机数目多的Agent系统中,其优点更为明显。     

移动Agent通信可靠性研究

提出基于Sama的移动Agent可靠通信方法来进行移动Agent通信,采用一种容错机制,使信息可靠传输.该通信方法旨在帮助提高在组内互相发送相同信息的情况下移动Agent通信的可靠性.     

GCS-MA: A group communication system for mobile agents

Reliable messaging is a key component necessary for mobile agent systems. Current researches focus on reliable one-to-one message delivery to mobile agents. But how to implement a group communication system for mobile agents remains an open issue, which is a powerful block that facilitates the development of fault-tolerant mobile agent systems. In this paper, we propose a group communication system for mobile agents (GCS-MA), which includes totally ordered multicast and membership management functions. We divide a group of mobile agents into several agent clusters, and each agent cluster consists of all mobile agents residing in the same sub-network and is managed by a special module, named coordinator. Then, all coordinators form a ring-based overlay for interchanging messages between clusters. We present a token-based algorithm, an intra-cluster messaging algorithm and an inter-cluster migration algorithm to achieve atomicity and total ordering properties of multicast messages, by building a membership protocol on top of the clustering and failure detection mechanisms. Performance issues of the proposed system have been analysed through simulations. We also describe the application of the proposed system in the context of the service cooperation middleware (SCM) project.     

一种基于指向路径分次删剪的移动Agent通信算法

在移动agent环境下，agent的移动为应用程序的开发提供了更灵活的通信处理方式，但也同时对通信算法的设计提出了许多挑战，其中最突出的就是由于消息传输和agent移动之间的异步性而造成的通信不可靠问题。针对目前解决该问题的各种机制和算法的不足之处，该文提出了一种新的agent通信算法——S—COMP，它综合采用了Home寻址、途经节点转发、指向路径分次删剪和集中同步等手段，能够适应具有不同移动和通信特点的agent的通信需要，在确保消息传输可靠性的同时兼顾了效率和适应性。     

An optimal scheduling algorithm for an agent-based multicast strategy on irregular networks

This paper describes an agent-based approach for scheduling multiple multicast on wormhole switch-based networks with irregular topologies. Multicast/broadcast is an important communication pattern, with applications in collective communication operations such as barrier synchronization and global combining. Our approach assigns an agent to each subtree of switches such that the agents can exchange information efficiently and independently. The entire multicast problem is then recursively solved with each agent sending message to those switches that it is responsible for. In this way, communication is localized by the assignment of agents to subtrees. This idea can be easily generalized to multiple multicast since the order of message passing among agents can be interleaved for different multicasts. The key to the performance of this agent-based approach is the message-passing scheduling between agents and the destination processors. We propose an optimal scheduling algorithm, called ForwardInSwitch to solve this problem. We conduct extensive experiments to demonstrate the efficiency of our approach by comparing our results with SPCCO, a highly efficient multicast algorithm reported in literature. We found that SPCCO suffers link contention when the number of simultaneous multiple multicast becomes large. On the other hand, our agent-based approach achieves better performance in large cases.