谈足球守门员的出击

对足球守门员出击的重要性、时机和应注意的事项进行了初步探讨     

基于Honeypot技术的网络入侵检测系统

利用Honeypot(蜜罐)技术设计了一种新的网络入侵检测系统。Honeypot技术是入侵检测技术的一个重要发展方向,已经发展成为诱骗攻击者的一种非常有效而实用的方法,不仅可以转移入侵者的攻击,保护主机和网络不受入侵,而且可以为入侵的取证提供重要的线索和信息,成功地实现了对网络入侵的跟踪与分析,具有一定的实用价值。     

浅谈快攻在教学中学生易犯的错误与纠正方法

快攻是篮球战术中的重点部分。通过钻研教材、查阅资料和教学实践,总结和探讨出学生在快攻中易犯的错误和一些相应的纠正方法,便于学生掌握正确的战术,提高其教学质量。     

浅析黑客攻击常用手段及安全防护

黑客的各种攻击手段严重威胁着Internet的安全,文章阐述了黑客攻击的一般步骤,并着重介绍了黑客攻击的常用手段以及相对应的防范措施.     

对排球发球区扩大后的新思考

排球运动有着漫长的发展历史,新技术、战术的不断涌现,给排球运动的发展增添了新的生机。但规则的不断修改又给比赛的可观赏性及技术革新带来了新的平衡,从而促进排球运动不断地向前发展。     

江汉大学女足在2002年全国联赛中进攻情况的统计与分析

通过对江大女足在2002年全国女足联赛中进攻情况的临场统计,并与全国九运会女足比赛相关数据进行对比,分析结果表明:江大女足在比赛中造成进攻失误的主要原因是传球失误,指出加强传接球训练是当前提高我国优秀女子足球队进攻质量的关键环节.     

Chlorine Truck Attack Consequences and Mitigation

We develop and apply an integrated modeling system to estimate fatalities from intentional release of 17 tons of chlorine from a tank truck in a generic urban area. A public response model specifies locations and actions of the populace. A chemical source term model predicts initial characteristics of the chlorine vapor and aerosol cloud. An atmospheric dispersion model predicts cloud spreading and movement. A building air exchange model simulates movement of chlorine from outdoors into buildings at each location. A dose‐response model translates chlorine exposures into predicted fatalities. Important parameters outside defender control include wind speed, atmospheric stability class, amount of chlorine released, and dose‐response model parameters. Without fast and effective defense response, with 2.5 m/sec wind and stability class F, we estimate approximately 4,000 (half within ～10 minutes) to 30,000 fatalities (half within ～20 minutes), depending on dose‐response model. Although we assume 7% of the population was outdoors, they represent 60–90% of fatalities. Changing weather conditions result in approximately 50–90% lower total fatalities. Measures such as sheltering in place, evacuation, and use of security barriers and cryogenic storage can reduce fatalities, sometimes by 50% or more, depending on response speed and other factors.     

有限域上Chebyshev映射的周期性分析

基于有限域上Chebyshev映射的公钥密码系统的安全性直接取决于Chebyshev映射的周期性。利用矩阵变换讨论有限域ZN上Chebyshev映射的周期性问题，并给出一种快速的寻找周期的方法，从而使得对有限域上Cheyshev公钥加密方案的攻击成为可能。     

From the Trenches: Attacking First-Time Women Candidates for Congress

SUMMARY

Women candidates in the United States no longer enjoy a “compassion advantage” when running against male candidates. First-time women congressional candidates in open seats are especially vulnerable to excessively aggressive negative attacks from their male opponents because (1) high-tech message delivery systems make attack campaigning easy; (2) attack messages attract more attention than positive messages and get the voters to pay attention; (3) large sums of money can be raised for these attacks from national interest groups by emphasizing the national importance of Congressional races; (4) first-time women candidates who are not elected officials do not have the public record and visibility that could insulate them from the abusive distortions of their views and even of their physical appearance; (5) the press does a poor job of covering suburban-rural races and independent fact checking is virtually nonexistent; and (6) since 9/11, terrorism has become a major issue and women are apt to be portrayed as too inexperienced to be trusted with protecting the national defense.     

Should Cities Invest in Sheltering‐in‐Place Measures Against Chlorine Truck Attacks by Terrorists?

After an intentional release of chlorine in an office district, public responses such as sheltering‐in‐place could save many lives if rapid enough. However, previous work does not estimate how fast and effective such responses would be for several possible investments in attack detection, public alert, and building ventilation, nor whether such measures would be cost effective. We estimate public response times with investment options in place, and resulting changes in fatalities as well as system costs, including false alarm costs, and cost effectiveness in terms of cost per net death avoided. The measures do have life‐saving potential, especially if all response times are at or near the lower limits of the ranges assumed in this article. However, due to uncertainties, it is not clear that responses would be rapid enough to save many people. In some cases total fatalities would increase, since sheltering after chlorine vapor has already entered buildings can increase occupants’ chlorine exposure. None of the options considered have median cost per statistical life saved meeting a cost‐effectiveness threshold of $6.5 million across all of the chlorine exposure dose‐response and ingress‐delay models considered here, even if there were one attack per year in the area covered by the system. Given these and other issues discussed in this article, at this point investments to improve sheltering‐in‐place capability appear not to be robust strategies for reducing fatalities from chlorine attack in an office district.