基于云PDR的区域物流能力评价研究

物流能力的提升是区域经济社会发展面临的重要问题。构建包括物流人才、物流基础设施、物流产出规模、物流发展环境四个一级指标在内的区域物流能力评价指标体系,以中国7个区域及其中20个省(市)的相关数据为样本,基于云概率优势关系(云PDR)方法进行评价,并据此从"综合水平-波动"和"投入-产出"两方面对样本分类。结果显示:在物流能力的水平和波动方面,各区域及省(市)差异显著,具有不同的驱动因素与薄弱环节,分属于积极的持续提升型、高效的持续提升型、低效的稳定发展型、低效的探索追赶型和保守落后型五种类型。因此,应结合不同地区所属类型的特征采取不同发展对策:物流发展处于保守落后型的区域应进一步加强物流发展意识、物流能力与发展水平相对平稳的区域应加快物流基础设施建设、物流发展相对活跃的区域应完善物流人才培养体系、物流能力与发展水平较高的区域应提升物流投入产出比,推动区域物流能力的全面提升。     

关于“文化工业”本质的再思考

"文化工业"理论是阿多诺哲学思想的重要组成部分,其内容蕴含着对于商品拜物教和技术的双重批判。然而,很多学者往往从单一角度入手探求其本质所在,得出的结论虽有合理之处却最终流于片面。事实上,商品拜物教和技术在阿多诺眼中绝非相互隔绝,二者完全可统一于西方哲学"同一性"传统之下。而只有以此为基点进行分析,才能正确揭示出"文化工业"对人类进行双重统治的本质。     

A concentration approach to sensitivity studies in statistical estimation problems

It is shown that the concept of concentration is of potential interest in the sensitivity study of some parameters and related estimators. Basic ideas are introduced for a real parameter θ>0 together with graphical representations using Lorenz curves of concentration. Examples based on the mean, standard deviation and variance are provided for some classical distributions. This concentration approach is also discussed in relation with influence functions. Special emphasis is given to the average concentration of an estimator which provides a sensitivity measure allowing one to compare several estimators of the same parameter. Properties of this measure are investigated through simulation studies and its practical interest is illustrated by examples based on the trimmed mean and the Winsorized variance.     

The Characterization of the Symmetric Lorenz Curves by Doubly Truncated Mean Function

We characterize symmetric Lorenz curves by the relation m(x, μ²/x) = μ (where μ =E(X) and m(x, y) = E(X | x ≤ X ≤ y) is the doubly truncated mean function). We establish that the points of the r.v. which generate the symmetric points on the Lorenz curve are x and μ²/x, and that all the distribution functions defined on the same support which are generators of the symmetric Lorenz curves have the same mean. We obtain the conditions under which doubly truncated distributions generate symmetrical Lorenz curves.     

A test for second order stochastic dominance

In this paper we propose a test for second order stochastic dominance (SSD), for the case where both distribution functions are unknown. This is a generalization of a test proposed by Deshpande and Singh (1985), who compare a new random prospect with a known distribution function. We then show that our test is based on comparing the mean minus one half of Gini's mean difference of the distributions, which is known to be a necessary condition for SSD, as developed in the economics literature (Yitzhaki, 1982).     

时滞反馈混沌同步及其抗噪优越性

噪声抑制是混沌同步通信急于要解决的关键问题之一。混沌系统的反馈同步一般采用非时滞反馈方式,该文提出了混沌系统时滞反馈同步抑噪的方法,并以Lorenz混沌系统为例,证明了驱动系统和响应系统均为Lorenz混沌系统时,采用时滞反馈控制,驱动系统和响应系统同步稳定的充分条件。文中将时滞反馈控制同步用于噪声抑制,表明效果比一般同步方式好很多。通过模拟存在信道噪声的情况下,采用Lorenz系统用参数调制进行信号传输,证实了时滞反馈同步的抗噪优越性。     

On the axiomatic treatment of the ϕ-mean

Summary We extend to masses on a real interval the notion of ϕ-mean, usually considered in the context of σ-additive probabilities or probability distribution functions, and consider some axiomatic treatments of it at different levels of masses (simple masses, compact support masses, tight masses, arbitrary masses). Moreover, as an important special case, we get axiomatic systems for general means, as well. We also prove that the usual axiomatic system “Consistency with Certainty+Associativity+Monotonicity” characterizes the ϕ-mean of masses with arbitrary compact support and that, already at tight masses level, this system is not adequate. We note that the analytical tool used to define the ϕ-mean is the Choquet integral. Work performed under the auspices of the National Group: “Inferenza Statistica: basi probabilistiche e sviluppi metodologici” (MURST 40%).     

Impossibility theorems for normal form games

Two recent papers (Cubitt and Sugden, 1994; Samuelson, 1992) have established impossibility results which cast doubt on the coherence of the assumption of common knowledge of rationality'. It is shown that the Cubitt–Sugden result is the more powerful of the two impossibilities. Second, it is proved that the existence of a quasi-strict equilibrium is sufficient to construct sets which satisfy the Cubitt–Sugden axioms. This fact is used to establish that their impossibility result cannot arise in 2-player games. Finally, it is shown that if a weak symmetry postulate is added, a new impossibility result arises for this class of games.