大型公共场所突发事件下人员疏散仿真研究

随着突发事件的频繁发生,人员疏散任务日益紧迫.针对突发事件下恐慌心理对人员疏散的影响,采用元胞自动机理论对人员疏散进行建模,提出逃生收益的概念,引入动态参数来描述逃生人员的逃生目的性及其周围的逃生环境,并分析了人员恐慌心理对逃生行人流产生的影响及由此形成的一些基本规律,如人群拱形分布、拥塞、间歇性出口人流等.仿真结果表明,运用逃生收益规则对人员紧急疏散的模拟很好地再现了人员紧急疏散过程及疏散状况,其模型更能体现真实的疏散情况.     

基于元胞自动机的应急疏散系统仿真研究

分析了紧急情况下人员疏散的难点,提出了应急系统人员疏散策略,设计了一种基于CA的人员疏散模型.通过模型仿真,分析模型中相关参数对疏散效果的影响,在此基础上对人员疏散模型中地场方法进行改进,模拟结果表明,基于CA的应急疏散仿真能够很好的模拟建筑内人员应急疏散行为及紧急事件的发展情况.同时该仿真方法具有直观性、灵活性和可扩展性,为应急管理研究提供了一个很好的研究思路.     

基于Pathfinder高校高层学生公寓火灾疏散仿真模拟研究

目前,高层建筑在高校建筑群中的数量快速增加,但出现了火灾疏散逃生的难题。因此,基于建筑信息模型(Building Information Modeling,BIM)技术和Pathfinder疏散模拟软件对某高校第23栋高层学生公寓楼进行人员疏散模拟,分析该学生公寓在应急逃生疏散中存在的安全隐患。从无人为干预下的数值模拟试验结果中得出,该高层学生公寓出口的利用率较低,疏散过程中楼道人员密度大,存在发生二次事故的风险。     

基于社会力模型的民用机场航站楼消防安全评价

针对以往单独进行火灾烟气蔓延模拟以及忽略疏散过程中人自身因素、人与人之间相互作用和环境对人的作用以评估航站楼消防安全的现状,基于国内某机场航站楼旅客进出港的过程,运用社会力模型模拟仿真航站楼内人员流动,同时采用火灾动力模拟软件FDS模型结合楼内设施模拟分析特定火灾背景下航站楼内火灾烟气蔓延,在此基础上,仿真模拟航站楼内人员疏散情况,分析不同火灾场景下航站楼的人员安全疏散时间、各个疏散通道疏散人数,进而研究安全出口宽度设置对于人员疏散时间的影响。与常用的安全评价方法进行对比分析,基于社会力模型和FDS模型的航站楼仿真安全评价方法考虑了旅客流动的分布特征和随机性,模拟更接近于真实的疏散场景。     

基于元胞自动机和模糊理论的人群疏散仿真

基于元胞自动机和模糊理论建立了人群疏散模型,对教学楼内的人群疏散过程进行了模拟。该模型根据人员对建筑物的熟悉程度、周围人员的吸引力设计元胞行为准则,并且采用模糊隶属度定义人员的体能状态及人员对环境的熟悉程度。实验结果表明,该仿真模型能够较好地模拟紧急状况下的人群疏散过程。     

隧道火灾疏散模型实时仿真算法的实现

由于隧道火灾的人员疏散难题,提出一种基于网格选择的隧道火灾人员疏散模型算法,设计了人员类型、奔跑速度、奔跑方向、人员所在环境等疏散属性参数,建立基于网格化离散场变量和坐标值的仿真模型。该算法克服了常用的元胞自动机算法计算量大,实时仿真比较困难的缺点。最后,利用Open Inventor进行了计算机仿真,并应用该仿真模型进行了分析,从逃生通道对疏散时间的影响及诱导标志设计对疏散时间的影响两方面验证了模型的有效性,并可直观地为安全疏散设计提供理论依据。     

元胞自动机地铁人员疏散模型仿真

基于元胞自动机模型对地铁人员疏散进行研究,通过对地铁的疏散个体微观建模,构建出元胞的移动规则,从而确定元胞下一时间步长的移动路径。针对地铁紧急情况下的疏散情形,提出了两种基于元胞自动机的疏散规则:概率计算方法和元胞空间场吸引法。利用VC++开发环境与OpenGL图形库对地铁的人员疏散情况进行仿真,描述不同疏散规则下的地铁疏散整个动态过程,并分别模拟得出不同的疏散效率,从而为指导地铁紧急情况下人员疏散提供理论依据。     

基于Agent的应急疏散模型研究

根据突发事件出现的等级,选择安全区域,并采用适当的疏散方式,选择受灾区域的周边安全区域作为避难所;通过分析影响应急情况下人员选择目的地的因素,对人员疏散行为直观分析并结合人机功效评估,对疏散行为规范,建立基于Agent的应急疏散人员避难所选择模型。通过设定可能影响人员疏散的多种可能因素,该模型能够比较真实地模拟紧急情况下的人员疏散状态。仿真过程与实际情况相似,方法可广泛用于人员应急疏散过程分析研究。     

高铁车厢内部紧急情况下人员疏散仿真研究

在引入元胞自动机理论的基础上,模拟分析了紧急情况下人员生理及心理的不同对疏散过程的影响,通过人员动态调整自身行为,并引入人员竞争力,对人员疏散过程建立模型。在疏散过程中,根据存在着一定程度的外部干扰因素,提出疏散干扰度概念。计算机仿真的结果表明,考虑人员竞争力,以及出口疏散干扰的问题,可以更加真实地模拟人员紧急疏散过程和疏散状况。     

802.11网络中基于博弈理论的可变带宽信道分配研究

802.11网络中节点的理性和自私性导致可变带宽信道分配的低公平性、低负载均衡性及低社会效率问题.基于非合作博弈理论将可变带宽信道分配问题建模成策略型博弈模型.首先,给出问题的纳什均衡分配策略,证明了纳什均衡点的存在;然后,针对纳什均衡策略社会效率低的问题,提出一种基于支付的激励机制,使可变带宽信道分配过程收敛到占优决策均衡状态,从而系统整体吞吐量性能达到全局最优;并分析了上述两种策略的公平性和负载均衡问题;最后,给出达到纳什均衡和全局最优状态的可变带宽信道分配算法.仿真结果表明,纳什均衡策略能够获得好的公平性,而全局最优策略的负载均衡和社会效率性能要优于纳什均衡策略.     

Computing the Nash Bargaining Solution for Multiple Players in Discrete-Time Markov Chains Games

Abstract

This paper presents a novel method for computing the Nash bargaining equilibrium for finite, ergodic and controllable Markov chains games. To solve the bargaining process we first set the disagreement point as the Nash equilibrium of the problem, then to find the new agreement point we follow the bargaining model presented by Nash. We exemplify the game formulation in terms of nonlinear programing equations implementing the Lagrange principle. For ensuring the convergence of the game to an equilibrium point we employ the Tikhonov’s regularization method. For solving the bargaining problem we make use of the extraproximal optimization approach. Finally, we validate the proposed method by a numerical example for a three-person bargaining situation.     

Modeling Multileader–Follower Noncooperative Stackelberg Games

This paper presents a Stackelberg–Nash game for modeling multiple leaders and followers. The model involves two Nash games restricted by a Stackelberg game. We propose a computational approach to find the equilibrium point based on the extraproximal method for ergodic controlled finite Markov chains. The extraproximal method consists of a two-step iterated procedure: the first step is a prediction and the second is a basic adjustment of the previous step. We formulate the game as coupled nonlinear programming problems using the Lagrange principle. The Tikhonov’s regularization method is used to guarantee the convergence to a unique equilibrium point. Validity of the method is demonstrated applying this framework to model an oligopoly competition.     

The Nash Equilibrium Point of Dynamic Games Using Evolutionary Algorithms in Linear Dynamics and Quadratic System

In this paper, examining some games, we show that classical techniques are not always effective for games with not many stages and players and it can’t be claimed that these techniques of solution always obtain the optimal and actual Nash equilibrium point. For solving these problems, two evolutionary algorithms are then presented based on the population to solve general dynamic games. The first algorithm is based on the genetic algorithm and we use genetic algorithms to model the players' learning process in several models and evaluate them in terms of their convergence to the Nash Equilibrium. in the second algorithm, a Particle Swarm Intelligence Optimization (PSO) technique is presented to accelerate solutions’ convergence. It is claimed that both techniques can find the actual Nash equilibrium point of the game keeping the problem’s generality and without imposing any limitation on it and without being caught by the local Nash equilibrium point. The results clearly show the benefits of the proposed approach in terms of both the quality of solutions and efficiency.     

Ad Hoc网络中基于重复博弈的攻击预测模型

大多数入侵检测系统预测攻击行为能力较弱,不能实时主动地响应攻击。针对该问题,提出一种基于重复博弈的攻击预测模型。通过建立入侵者和入侵检测系统之间的阶段博弈模型,给出阶段博弈的纳什均衡,并求出重复博弈情况下的子博弈精炼纳什均衡。使用QRE模型预测攻击者和防御者在博弈阶段1~t中选择各种策略的概率,利用Gambit分析得出预测结果。基于GloMoSim的仿真结果表明,相比纳什均衡模型,QRE均衡模型的预测效果更好。     

Nash equilibria: Complexity,symmetries, and approximation

We survey recent joint work with Christos Papadimitriou and Paul Goldberg on the computational complexity of Nash equilibria. We show that finding a Nash equilibrium in normal form games is computationally intractable, but in an unusual way. It does belong to the class NP; but Nash’s theorem, showing that a Nash equilibrium always exists, makes the possibility that it is also NP-complete rather unlikely. We show instead that the problem is as hard computationally as finding Brouwer fixed points, in a precise technical sense, giving rise to a new complexity class called PPAD. The existence of the Nash equilibrium was established via Brouwer’s fixed-point theorem; hence, we provide a computational converse to Nash’s theorem.To alleviate the negative implications of this result for the predictive power of the Nash equilibrium, it seems natural to study the complexity of approximate equilibria: an efficient approximation scheme would imply that players could in principle come arbitrarily close to a Nash equilibrium given enough time. We review recent work on computing approximate equilibria and conclude by studying how symmetries may affect the structure and approximation of Nash equilibria. Nash showed that every symmetric game has a symmetric equilibrium. We complement this theorem with a rich set of structural results for a broader, and more interesting class of games with symmetries, called anonymous games.     

Racing to the precipice: a model of artificial intelligence development

This paper presents a simple model of an AI (artificial intelligence) arms race, where several development teams race to build the first AI. Under the assumption that the first AI will be very powerful and transformative, each team is incentivised to finish first—by skimping on safety precautions if need be. This paper presents the Nash equilibrium of this process, where each team takes the correct amount of safety precautions in the arms race. Having extra development teams and extra enmity between teams can increase the danger of an AI disaster, especially if risk-taking is more important than skill in developing the AI. Surprisingly, information also increases the risks: the more teams know about each others’ capabilities (and about their own), the more the danger increases. Should these results persist in more realistic models and analysis, it points the way to methods of increasing the chance of the safe development of AI.     

Location–price competition with externality: an application to the Tenerife tram

This paper presents a location–price equilibrium problem on a tree. A sufficient condition for having a Nash equilibrium in a spatial competition model that incorporates price, transport, and externality costs is given. This condition implies both competitors are located at the same point, a vertex that is the unique median of the tree. However, this is not an equilibrium necessary condition. Some examples show that not all medians are equilibria. Finally, an application to the Tenerife tram is presented.     

Is the Leading Role Desirable?: A Simulation Analysis of the Stackelberg Behavior in World Petroleum Market

This article explores extraction profiles in the Stackelberg equilibrium of exhaustible resource industry. Calibrated with real data of world petroleum market, the Stackelberg and Cournot–Nash equilibriums are solved numerically. The properties of the Stackelberg equilibrium are compared and contrasted with the benchmark open-loop Cournot–Nash equilibrium. Simulation results indicate that the leader’s gains are limited in the Stackelberg strategic setting. Methodologically, this article pioneers solving the Stackelberg game numerically in a dynamic and empirical model.     

R&D投资竞赛模型及其复杂性仿真研究

提出了一个双寡头R&;D投资竞赛的非线性动力学离散模型,接着对该模型中有经济意义的Nash均衡点的稳定性以及其Hopf分岔的存在性进行了分析。最后通过计算第一Lyapunov指数,对模型产生的Hopf分岔的方向与稳定性进行了计算和证明,并进行了仿真模拟。