Awareness of Distributed Denial of Service Attacks' Dangers: Role of Internet Pricing Mechanisms

Denial of Service (DoS) attacks consist of overwhelming a server, a network or a Web site in order to paralyze its normal activity. The additional parameter in Distributed Denial of Service (DdoS) attacks is the distributing strategy. It means that DDoS attacks do not come from a single computer but stem from all accessible channels and servers. Consequences are multiple, ranging from system errors, temporary inability to access the Web site for normal users to challenging the actual reliability of the Internet. Despite this, Internet users show carelessness. The explanation lies in the specificities of DDoS attacks. We explore possibilities to raise users' awareness about the actual amplitude of problems caused by DDoS attacks. We suggest a careful examination of Internet pricing mechanisms and switching from flat to usage-constraining pricing schemes.     

美国空军卫星控制网的现状与发展趋势

近几年的几场局部战争部分表明了现代军事航天系统的重要性。本文主要介绍了美国最重要的一个军事航天测控网－－空军卫星控制网的情况，希望能对了解美国军事航天测控体制有所帮助。     

我国产权制度的变迁及其趋势

我国私营经济是在传统的公有制经济的土壤中发展起来的,其发展必然与传统体制发生摩擦与冲突。本文总结了我国产权制度变革的路径,分析了影响私营经济可持续发展的产权制度障碍,根据我国产权制度改革的轨迹,预测了产权制度变迁的趋势和特征。     

Predicting the geo-temporal variations of crime and disorder

Traditional police boundaries—precincts, patrol districts, etc.—often fail to reflect the true distribution of criminal activity and thus do little to assist in the optimal allocation of police resources. This paper introduces methods for crime incident forecasting by focusing upon geographical areas of concern that transcend traditional policing boundaries. The computerised procedure utilises a geographical crime incidence-scanning algorithm to identify clusters with relatively high levels of crime (hot spots). These clusters provide sufficient data for training artificial neural networks (ANNs) capable of modelling trends within them. The approach to ANN specification and estimation is enhanced by application of a novel and noteworthy approach, the Gamma test (GT).     

高等职业院校实践学分制的思考

高等职业院校实施学分制是教育教学改革的必然趋势,因此,高等职业院校要勇于实践,不断探索。文章就高等职业院校如何实践学分制,提出了从制订学分制的政策、学分制的操作流程到建立学分制管理手段的一些建议。     

科学创新的人文动源系统

创新是当今世界发展的主题,科学创新是创新链条的初环,研究科学创新的动力系统成为一种必然.科学创新的人文内涵表现在各种人文要素对其影响上,这些结构要素的系统动力学效应成为科学创新的动力源泉.这些人文要素大体包括哲学、宗教、政治制度、法律、社会道德、文学和艺术等.它们主要从诱发基本观念、规范、情感三个角度对科学创新产生影响.     

供应链管理绩效评价及激励机制

本文通过分析供应链管理的特点、目标和内容，提出供应链管理绩效评价指标体系，其中矩阵指标具有一定的创新，且较好地反映了供应链企业之间的复杂关系。介绍了确定供应链管理的绩效指标值的两种方法，并分析了供应链管理六种激励模式。     

A comparison of several approximations to the power function of the likelihood ratio test in covariance structure analysis*

In this paper we compare alternative asymptotic approximations to the power of the likelihood ratio test used in covariance structure analysis for testing the fit of a model. Alternative expressions for the noncentrality parameter (ncp) lead to different approximations to the power function. It appears that for alternative covariance matrices close to the null hypothesis, the alternative ncp's lead to similar values, while for alternative covariance matrices far from H_o the different expressions for the ncp can conflict substantively. Monte Carlo evidence shows that the ncp proposed in Satorra and Saris (1985) gives the most accurate power approximations.     

论我国现行代理制度的缺陷及完善

代理制度是民商法中一项重要的法律制度,它在现代商品经济中起着不可或缺的作用。过去我国由于商品经济长期不发达,我国的民法,特别是其中的代理制度处于严重的滞后状态,这对我国目前市场经济的发展产生了负面影响。因此,对我国民事代理制度存在的缺陷加以检讨和反思,以期对我国的代理立法和实务有所裨益。     

On Sraffa's Standard commodity: is its price invariant with respect to changes in income distribution?

In his 1960 book, Sraffa suggested using a composite commodity,which he called the ‘Standard commodity’, to solveRicardo's search for an invariable measure of value, i.e., astandard capable of isolating the price movements of any othercommodity induced by changes in income distribution. The absencein Sraffa's book of an explicit proof of the invariance propertyof this standard gave rise to many misunderstandings about itsmeaning and its role as an invariable measure of value. In orderto clear up these questions, Bellino (On Sraffa's Standard commodity,Cambridge Journal of Economics, vol. 28, 121–32, 2004)has proposed a ‘proper’ definition of an ‘invariablemeasure of value’, showing that Sraffa's Standard commoditydoes fulfil the requirements of this definition. He claims thatthe fulfilment of this property (but not the constancy of its‘nominal’ price) qualifies the Standard commodityas an invariable measure of value. In this paper, a proof ofthe invariance of the price of the Standard commodity with respectto changes in income distribution is given, and the equivalenceof this property with Bellino's definition of invariance isshown.