多Agent系统中信任的动态性处理

信任是多Agent系统中进行决策和交互的重要内容。收集必要的信息确定信任关系,动态地管理、维护信任关系,以及监控和重估已有的信任关系是多Agent系统中信任管理的关键问题。虽然研究者对上述关键问题提出了一系列解决方案,但依然存在一些问题有待进一步解决。本文针对信任的动态性处理这一问题,在分析现有的典型信任模型基础之上,提出一个具有动态性的Confidence-Reputation信任模型。模型中,我们不仅考虑了Agent的直接交互历史(Confidence)和信誉(Reputation),同时也考虑了信任的本体性。     

基于社会规范准则和联合抵制的节点激励机制研究

P2P网络中的节点由于固有的理性将产生个人利益与系统性能相冲突的搭便车行为,从而极大地降低网络的性能和效用。在社会规范的基础上结合联合抵制敌我规则的思想,建立了一套应用于P2P网络的社会规范准则模型,该模型惩戒违反社会规范准则的节点,激励节点选择合作策略,并通过博弈收益分析给出模型均衡于合作策略的条件。仿真实验结果表明,该模型能够有效地激励节点协作和抑制节点搭便车行为。     

基于多Agent的天战系统建模与仿真方法研究

简单介绍了复杂系统理论及其建模方法，分析了天战系统的总体行为特征，指出对天战系统的仿真研究需采用复杂适应系统（CAS）理论的研究方法，即采用基于Agent的建模仿真方法学来开展研究，概述了Agent和多Agent系统的概念及基于多Agent的仿真，并给出了一个基于高层体系结构（HLA）的天战系统的仿真框架，最后展望了将来的研究工作。     

Learning to Be Thoughtless: Social Norms and Individual Computation

This paper extends the literature on the evolution of norms with anagent-based modelcapturing a phenomenon that has been essentially ignored, namely thatindividual thought – orcomputing – is often inversely related to the strength of a social norm.Once a norm isentrenched, we conform thoughtlessly. In this model, agents learn how tobehave (what normto adopt), but – under a strategy I term Best Reply to Adaptive SampleEvidence – they also learnhow much to think about how to behave. How much they are thinking affects howthey behave,which – given how others behave – affects how much they think. Inshort, there is feedbackbetween the social (inter-agent) and internal (intra-agent) dynamics. Inaddition, we generate thestylized facts regarding the spatio-temporal evolution of norms: localconformity, global diversity,and punctuated equilibria.     

基于Agent的社会学仿真研究

基于Agent的建模与仿真方法被应用到社会科学研究领域形成了基于Agent的社会学仿真这一新的交叉研究领域.研究的目标是在计算机上创建一个人工社会来观察个体交互涌现的社会现象.人工社会是一个复杂的多Agent模型.在简单回顾了社会学仿真发展历史之后,对人工社会模型的复杂度进行了探讨,并将多Agent模型与其他社会学仿真模型进行了比较研究.基于Agent的社会学仿真目前还缺少公认的方法学流程,提出了一个人工社会的概念模型,并探索了人工社会模型的构建流程.最后对基于Agent的社会学仿真方法的适用范围进行了讨论.     

基于多Agent复杂系统仿真平台研究

复杂性科学是研究复杂系统和复杂性的一门新兴的交叉学科.基于多主体(Agent)复杂系统仿真技术是研究复杂系统复杂性产生机制的有效手段之一,在众多领域得到广泛应用.为了使研究者从复杂的软件编程中解放出来,集中精力进行科学研究,开发高效的、易用的仿真平台成为推动基于多Agent复杂系统仿真技术进步的关键.针对目前多Agent仿真平台存在的局限性,进行仿真平台的结构设计,并开发了原型系统.最后,利用热虫(Heatbug)模型验证仿真平台的有效性.     

基于Matlab的感应加热电源系统仿真

感应加热电源系统包含电路、电力电子、控制、保护等模块,系统的分析和设计具有一定的难度。建立感应加热电源系统的仿真模型,有利于对系统性能进行分析,对于系统参数的设计具有重要的指导作用。该文应用Matlab／Simulink、电力系统模块库（SimPowerSystems）和通信系统模块库（Communications Blockset）,构建了感应加热电源系统的完整仿真模型。具体分析了功率控制、锁相环和负荷模块的构成。最后给出仿真结果,并通过与JGRC30-150感应加热电源系统的实验波形比较,证明所建仿真模型的正确性。     

密度场下的短程社会力模型

密度场是行人感知周围人群密度信息的有效工具.它提供一种直观且高效的手段,在人群模拟中快速调整行人移动方向.在人群建模的研究领域中,社会力模型是相当经典的方法,能够模拟一些常见的自组织现象.但是,其依然存在一些不足,比如人群数目的增长使得模型的时间复杂度呈指数增长,同时还存在行人重叠问题以及行人振荡问题等.利用密度场对社会力模型进行了改进,首先提出行人的受力邻域与墙壁的排斥距离来降低算法复杂性,其次为社会力模型建立了相匹配的网格密度场以使行人能够绕开高密度区域,最后提出了密度导向阈值这一概念,使得人群密度值大于密度导向阈值时,行人会综合目标方向与周围的低密度方向作为新方向.实验结果表明,改进后的模型不仅能模拟出基本的人群自组织现象,而且在时间复杂度方面有明显优势.     

Induced Convolution Operator Norms of Linear Dynamical Systems

In this paper we develop explicit formulas for induced convolution operator norms and their bounds. These results generalize established induced operator norms for linear dynamical systems with various classes of input–output signal pairs. Date received: April 1, 1999. Date revised: February 21, 2000.     

适用于智能交通系统的集成仿真

通过对智能交通系统体系架构的分析,提出了由建模层、仿真层、数据层和交互层组成的集成架构,构成了基于CORBA的集成仿真环境。     

Formation-Containment Control Using Dynamic Event-Triggering Mechanism for Multi-Agent Systems

The paper proposes a novel approach for formation-containment control based on a dynamic event-triggering mechanism for multi-agent systems. The leader-leader and follower-follower communications are reduced by utilizing the distributed dynamic event-triggered framework. We consider two separate sets of design parameters: one set comprising control and dynamic event-triggering parameters for the leaders and a second set similar to the first one with different values for the followers. The proposed algorithm includes two novel stages of co-design optimization to simultaneously compute the two sets of parameters. The design optimizations are convex and use the weighted sum approach to enable a structured trade-off between the formation-containment convergence rate and associated communications. Simulations based on non-holonomic mobile robot multi-agent systems quantify the effectiveness of the proposed approach.      

Adaptive Containment Control for Fractional-Order Nonlinear Multi-Agent Systems With Time-Varying Parameters

This paper investigates adaptive containment control for a class of fractional-order multi-agent systems (FOMASs) with time-varying parameters and disturbances. By using the bounded estimation method, the difficulty generated by the time-varying parameters and disturbances is overcome. The command filter is introduced to solve the complexity problem inherent in adaptive backstepping control. Meanwhile, in order to eliminate the effect of filter errors, a novel distributed error compensating scheme is constructed, in which only the local information from the neighbor agents is utilized. Then, a distributed adaptive containment control scheme for FOMASs is developed based on backstepping to guarantee that the outputs of all the followers are steered to the convex hull spanned by the leaders. Based on the extension of Barbalat’s lemma to fractional-order integrals, it can be proven that the containment errors and the compensating signals have asymptotic convergence. Finally, three simulation examples are given to show the feasibility and effectiveness of the proposed control method.      

公共品实验中社会规范形成的研究及仿真

公共品理论一直为宏观经济学家所关注。经济学家们做了大量的实验来研究公共品实验中的个体行为,并提出很多模型。文章用基于主体的仿真技术来模拟公共品实验,将个体的互惠性和社会倾向结合起来对人的行为进行建模,并利用遗传算法对个体的行为策略作进化,使得可以清楚地从实验过程中看到个体之间的交互作用和个体对公共池的捐献情况。仿真结果表明:在无外界条件干预的情况下,通过个体的互惠行为,公共品数量会趋向稳定,并且能在群体中形成稳定的社会规范。     

Multi-criteria assessment of user trust in Social Reviewing Systems with subjective logic fusion

By now people’s opinions and actions are more and more strongly influenced by what is posted and shared on the various social networks. Thus, malicious users can purposely manipulate other users posting fake news/reviews. In order to face this challenge, modern online social networks are beginning to adopt tool for user trustworthiness assessment. Current assessment solutions mainly adopt multi-criteria frameworks for user trustworthiness assessment but fail at properly dealing with uncertainty and vagueness in computed/collected scores and aggregating them in a robust manner. In this paper, we propose a larger set of criteria than existing related works, and the use of subjective logic to represent and combine subjective and objective scores. Specifically, several of assessment criteria are introduced for verifying user trust from different point of views (usefulness and quality of user reviews, users’ influence/importance in terms of activities and centrality within the social network, time dependent crown consensus investigating aspect-based sentiments and opinions of reviews w.r.t. the majority), aiming at improving accuracy and precision in trust estimation. The available fusion operators in the literature of subjective logic have been compared so as to find the best one fitting the needs of trust estimation. The proposed solution has been implemented and evaluated against public Yelp data-sets so as to prove its effectiveness and efficiency w.r.t. existing related works within the literature.     

系统可靠性的计算机仿真方法

随着各种新型复杂系统的建立和工程项目的实施,常规可靠性设计理论与工程实践的矛盾日益突出。当进行可靠性计算时,由随机应力和随机强度的概率密度函数来获取功能函数的概率密度函数较困难,该文就如何将常规可靠性仿真方法推广进行计算机可靠性仿真,提出了将模糊可靠性设计问题转化为常规可靠性设计问题求解的思路,给出了转化的基本原理和方法,由此推出了一系列的计算公式及其仿真方法,从而使得可靠性设计方法能同时处理设计中的随机性和模糊性。     

基于多Agent计算机仿真实验平台Swarm的综述

结合具体实例“热虫实验”,解释了Swarm在人工世界环境下进行计算机仿真模拟的基本思想,探讨了Swarm的主要概念和系统结构;进而以Java语言为例介绍了面向对象思想用于Swarm编程的基本情况,并对Swarm所提供的软件工具包给出了Java形式的详细说明。     

智能控制系统仿真技术分析

本文详细地叙述了智能控制系统仿真的实现过程,针对其中涉及的数学原理、数值算法、编程应注意的问题、仿真精度、几种典型干扰的仿真仿真模型、仿真技巧和程序调试等常见问题进行了方法讨论和技术分析,并用Matlab语言给出了一个具体模糊控制系统的仿真例子。     

结合全局与双重局部信息的社交推荐

随着Web2.0的飞速发展,社交推荐逐渐成为推荐领域近几年的研究热点。如何更有效地利用用户的社交关系是社交推荐的关键,目前的社交推荐算法主要引入的是用户之间的直接联系(明确关系)。将社交关系进一步细分为明确关系和隐含关系,并结合历史评分得到的用户声誉信息刻画了由用户全局信息(声誉)与局部信息(明确关系和隐含关系)所构成的推荐系统框架。与现有的社交推荐算法相比,所提出的算法更全面地分析了用户的社交关系,且具有良好的可解释性。在Douban数据集和Epinions数据集上进行了实验,并将本算法与主流的推荐算法进行了比较,结果表明本算法具有更好的推荐精度。     

基于Multi—Agent的海上搜救仿真研究及应用

文章针对海上搜救仿真这种典型的综合仿真系统的特点,以降低综合仿真系统的复杂度和研发费用,并且提供最大程度的辅助决策支持为目的,提出了包括仿真建模结构、控制结构和智能模型的基子Multi-Agent的复杂系统智能仿真方法。基于Multi-Agent的综合系统智能仿真体系结构引入了一种新的建模与仿真的思想和方法,从而形成了一套独特的仿真建模体系结构,提高了建模与仿真的通用性、可重用性、互操作性以及计算机仿真技术的辅助决策能力。     

A Computational Economy for IN Load Control Using a Multi-Agent System

Intelligent Networks (IN) are used in telecommunication networks to provide services that require a decision-making network element. The Service Control Point (SCP) can be overloaded when the number of service requests exceeds the SCPs designed capacity. Traditional IN load control algorithms assume a single service network model or use a centralized controller to find a solution. In this paper we propose and investigate a market-based model, in the form of a computational economy, for solving the distributed IN load control problem for a multi-service network. We investigate two algorithms, one price-oriented and the other resource-oriented, for finding the competitive equilibrium for this economy. We conclude that the price-oriented approach generally performs better and allows a greater level of distributed-decision making but suffers from an infeasible solution in real-time systems. Furthermore, we study a realization of this model as a multi-agent system (MAS) and investigate the communication overhead associated with running auctions for services.