浅析无线局域网安全

科技的发展使得无线网络以其独特的优越性逐渐成为发展的主流,然而随着无线网络的发展,安全性问题成为发展无线网络的瓶颈。为了保证无线局域网能够安全、正常的运行,通过对危害无线局域网的一些因素的分析,给出了相应的防护措施。     

Competitive attack,retaliation and performance: An expectancy-valence framework

This research examines how competitive attacks can best reduce the chances of retaliation. An expectancy–valence model is developed that views retaliation as a function of the subtlety of an attack: that is, its visibility, the difficulty rivals might have in responding to it in kind, and the importance or ‘centrality’ to rivals of the market under siege. Motivational theories suggest that all three of these independent variables need to be in place in order to elicit a response—or conversely, that low visibility, substantial response difficulty, or minimal centrality would each by itself be enough to prevent retaliation. This notion was not supported. Each one of the independent variables could serve as the ‘weak link of the chain,’ increasing the chances of retaliation. However, as predicted by expectancy theory, these variables selectively demonstrated some interactions that compound the threat of retaliation. In combination, high visibility and low levels of difficulty were especially likely to evoke responses from rivals. Finally, there appears to be a real incentive to avoid retaliation given its negative associations with performance.     

多层次入侵检测及其攻击树描述

引入攻击树来表示多层次入侵，并提出了一个基于攻击树的攻击说明语言。另外，还使用攻击树来对系统安全进行事前分析，并提出了权重的算法。最后，引入形式化语言Z语言来对攻击模式进行描述，并以IP-Spoofing为例构造了一个IP-Spoofing攻击模式。     

An evolutionary model of speculative attacks

We build an evolutionary model of currency crises incorporating learning through imitation and experimentation by heterogeneous agents. Foreign currency speculators in the model interact and learn over time through experimentation. Drawing on results from game theory, we show that the resulting dynamic converges to a unique long run equilibrium, in which the currency is “attacked” if the economic fundamentals are sufficiently adverse. Evolutionary selection is thus shown as a way to resolve the issue of indeterminacy of equilibria associated with models of currency crises.JEL Classification: C63, F31, D83, C72I am grateful to Jasmina Arifovic, Peter Garber, Pravin Krishna, Blake LeBaron, Nidhiya Menon, Srinivas Thiruvadanthai and Tiemen Woutersen for useful remarks and suggestions. All errors remain my own.     

投机性货币冲击引发货币危机的条件及防范

由投机性货币冲击所引发的固定汇率制崩溃给实行固定汇率制的国家(或地区)的经济发展蒙上了一层沉重的阴影。为此，本文运用国内外关于货币危机中货币投机性冲击理论的最新研究成果分析了欧洲货币危机和东南亚金融危机中投机冲击致胜的基本条件，进而提出了我国加入WTO后防范和化解人民币危机的相关措施。     

Devaluation of fixed exchange rates: optimal strategy in the presence of speculation

Summary. This paper analyzes devaluations in a fixed exchange rate system by endogenizing both the speculation and devaluation decisions. It is shown that deterministic devaluation rules are generally sub-optimal for the central bank. In order to deter speculation the central bank introduces uncertainty into the timing of devaluation. The nature this mixed strategy is derived, as is the optimal strategy for speculators. The analysis allows an explanation of successful devaluations that are not precipitated by a speculative attacks, even under perfect capital mobility. Received: May 17, 1999; revised version: June 2, 1999     

我国农村金融包容水平对农民健康状况的影响及区域差异

金融包容发展会促进经济增长和收入差距缩小,进而促进居民整体健康状况的改善。采用“中国家庭追踪调查”数据考察农村金融包容水平对农民健康状况的影响,结果表明：我国农村金融包容发展总体水平较低,且存在“东部较高、中部居中、西部较低”的区域差异;农村金融包容水平的提升有利于农民健康状况的改善,并且农村金融包容水平越低的地区该效应越大（西部最大,中部次之,东部最小）;当农民受到健康冲击时,当地农村金融包容水平的提升有助于缓冲其健康状况的恶化。应加快中、西部地区农村金融包容发展,在提升农村金融包容整体水平的同时缩小区域差异;要通过金融创新使更多的农民得到更多的健康保障,以金融包容发展抑制和消除因病致贫现象的发生。     

电子商务网站安全中的DDoS攻防博弈

文章对现今电子商务网站所面临的最具威胁性的攻击——分布式拒绝服务（DDoS）攻击的攻击机理作了较为详细的分析,并分析了针对DDoS攻击的不同攻击子类的特点及采取的应对防范措施,从而降低被攻击方受攻击后的损害程度。最后揭示了想要将DDoS攻击发生的可能性降到最低的一切防范措施的根本特性——社会性。     

CFM56-5B发动机启动失速故障分析

本文通过CFM56-5B发动机在启动过程中出现"ENG 1 START STALL"故障信息(非高原机场)排故全过程进行分析,提出了对启动过程中出现"ENG 1 START STALL"故障信息(非高原机场)排故建议和维护提示。     

浅析IPsec在IPv6网络安全中的应用

本文针对IPv4当前采用的安全机制,分析了包括IPsec在内的几种网络安全机制。对网络而言IP的安全是非常重要的,本文通过分析网络攻击的原型以及IPsec在网络层保护IP的措施,提出如何在IPv6下的保护IP首尾安全。最后,介绍了针对IPsec的一些新的攻击模式。