无线传感器网络入侵检测的重复博弈建模研究

通过分析无线传感器网络节点影响网络可用性及其整体性能的自私行为,提出了一种无线传感器网络入侵检测的重复博弈模型,集中于检测和响应传感器节点的自私行为以加强网络节点的协作性能,利用节点与其邻居节点进行的重复博弈过程,广播节点的效用变化,即时检测出网络节点的自私行为。通过对网络节点的自私行为引入惩戒机制,从而大大降低了节点背离协作的可能性。仿真结果表明,对节点的自私行为实施惩戒机制,可以大大增强节点间相互协作,从而保证网络的连通性。     

基于博奕论解析财务管理目标

综述了目前财务管理目标的不同观点,指出这些争论的不足和片面性,重新识别了企业中的不同利益体,并从博奕论角度重新解释了财务管理的目标,最终建立了基于博奕论的财务管理目标模式W＝i=1∑^nAiWi。     

The international reception of The Family of Man

This paper examines the role of The Family of Man in American cultural diplomacy. The exhibition was circulated around the world by the United States Information Agency (USIA), a government unit charged with distributing information about the culture and civic institutions of the US. The reception of the exhibition by the international viewing public is discussed. The discussion is informed, in part, by photographs documenting visitors to the exhibition.     

Photography and the Elphinstone Institution of Bombay

Abstract

Ralizing the potentials of photography, the Court of Directors of the East India company recommended to the Government of Bombay as early as 1845 ‘the encouragement of the study of this useful art of photography in any of the seientific or educational institutions under the control or inf1uence of your government’. They also offered to furnish students with the requisite apparatus, if they found it necessary to procure them from England¹. The proposal was repeated in their dispatch dated 29th December 1854, when they again expressed their desire to establish training in photography. Thereupon, W. Hart, Secretary to the Government of Bombay, requested the Board of Education of Bombay Presidency to submit a scheme for carrying out this project². Mr Stowell, Secretary to the Board of Education, called for the opinions of the Principal of the Elphinstone Institution, and of its Professor of Chemistry³. A small but interesting episode of early photography in India had its beginning in this way.     

关于餐馆消毒柜使用的经济学分析

目前,消毒柜是众多餐馆的必备消毒设备之一。但调查显示,由于使用成本等方面的原因,部分消毒柜往往成为摆设,没有起到应有的作用。文章从经济学角度对餐馆消毒柜使用问题进行分析。     

THE PAPER ENIGMA MACHINE

The Enigma Machine is a complex electromechanical device used by the Germans in World War II to achieve what they thought was complete communications security. While the original machine weighed over 20?lbs, the central mechanics of the machine can be simulated manually by manipulating strips of paper. A Paper Enigma is presented that can be cut out of a single sheet of paper. The resulting simulator is compatible with the electromechanical original in that messages can be encoded on one, and decoded on the other. Copies of The Paper Enigma can be downloaded from http://mckoss.com/crypto/enigma.htm.     

基于微分对策的多飞行器协同捕获空间划分

针对多飞行器协同围捕问题,提出一种基于微分对策的加权制导律下捕获空间划分方法。选取合适的性能函数,建立多对一协同围捕微分对策模型;利用哈密尔顿函数法求解得出飞行器和目标的最优控制策略,获得各飞行器的零控脱靶量的最优轨迹;以2个飞行器为例,设置1个2对1协同围捕场景,根据2个飞行器初始零控脱靶量的符号和大小关系,给出各飞行器单独拦截以及协同围捕状态下的相关定义;根据各飞行器零控脱靶量的最优轨迹,围绕初始零控脱靶量给出1种协同捕获空间的划分方法;设置3个具体的仿真场景,验证结果证明了该方法的准确性。     

Optimal resource allocation scheme for cognitive radio networks with relay selection based on game theory

In this paper,we present a non-transferable utility coalition graph game(NTU-CGG) based resource allocation scheme with relay selection for a downlink orthogonal frequency division multiplexing(OFDMA) based cognitive radio networks to maximize both system throughput and system fairness.In this algorithm,with the assistance of others SUs,SUs with less available channels to improve their throughput and fairness by forming a directed tree graph according to spectrum availability and traffic demands of SUs.So this scheme can effectively exploit both space and frequency diversity of the system.Performance results show that,NTU-CGG significantly improves system fairness level while not reducing the throughput comparing with other existing algorithms.     

Equilibrium stability of a nonlinear heterogeneous duopoly game with extrapolative foresight

We make a further attempt to investigate equilibrium stability of a nonlinear Cournot duopoly game with adaptive adjustment toward best reply by assuming heterogeneous firms where one firm only uses naive expectations whereas the other employs a simple forecast technology to form sophisticated expectations. More precisely, based on the knowledge of actual production of the competitor and its actual rate of change, the clever firm is able to evaluate its opponent's output in the near future by virtue of straightforward extrapolative foresight. We finally arrive at a conclusion that this seemingly rational mechanism takes a positive effect on convergence to equilibrium behavior. Inconsistent with common intuition, we demonstrate that stronger foresight ability is not always better to stabilize the equilibrium. Particularly, perfect foresight dose not give rise to the best stabilizing factor.