拟脐超曲面中的稳定积分流

设Ｎｎ是常曲率空间Ｍｎ＋１（ｃ）中的紧致拟脐超曲面．证明了在一些几何条件下，Ｎｎ中不存在ｐ－维稳定积分流，相应地，Ｎｎ的ｐ－维同调群消没．     

Fractional Lévy stable motion time-changed by gamma subordinator

Abstract

In this paper a new stochastic process is introduced by subordinating fractional Lévy stable motion (FLSM) with gamma process. This new process incorporates stochastic volatility in the parent process FLSM. Fractional order moments, tail asymptotic, codifference and persistence of signs long-range dependence of the new process are discussed. A step-by-step procedure for simulations of sample trajectories and estimation of the parameters of the introduced process are given. Our study complements and generalizes the results available on variance-gamma process and fractional Laplace motion in various directions, which are well studied processes in literature.     

“维护高校稳定”视野下思想政治教育的 功能及相关性分析

思想政治教育由于其所具有的导向、保证、育人和开发等功能必然是解决高校行为规范被全体师生认同问题的不二选择.只有彰显党团组织、辅导员、思想政治理论课教师、全体师生等的积极作用,才能充分发挥思想政治教育的功能,进而从根本上真正维护高校师生的思想情绪稳定、政治上的安定团结、教学科研和生活秩序稳定、校园环境安全的稳定.     

缩减人口还是稳定人口?————中国向何处去的命运之择

对“控制人口数量”基本国策的实现程度有基本完成和远未完成两种判定。主张稳定人口的基本完成论以人口过快增长得到有效遏制作依据,并为“人口-环境均衡论”、“零增长-可持续人口论”、“常量人口-压力消失论”和“人口冬天论”所支持。远未完成论则坚持将缩减人口作为中国新的人口发展战略:持续性的症结是规模而非均衡,一个能为土地生产力支持的人口并不一定能保证与环境均衡的持续,存在着间断;人口规模问题不存在技术、经济和制度解,老龄化并非衰亡,人口压力远未消失;体现人少优势、具有“釜底抽薪”作用的小规模人口将从根本上改变“人口多、底子北的基本国情,保障粮食安全,增加选择机会和维护发展的可持续性;而维持一个15亿的稳定人口,必将使我们陷入“规模泥潭”而断送中华民族的未来。     

羌语稳定型村寨语言使用现状及其成因分析

从整个羌族地区来看,汶川县雁门乡是羌语保持较好的地区之一,但不同村寨羌语保持状态却有很大差别.萝卜寨、白水村和通山村属于羌语稳定型村寨,主要特征体现在四个方面:羌语整体水平高,青少年词汇量大;代际传承尚未受到明显挑战;羌语使用频率高,使用范围较广;语言忠诚度高等.这些地区稳定使用羌语的因素主要是:地理环境相对封闭,羌族比例大;婚姻状况与语言认同,保障了羌语的代际间传承.     

Scale estimators for symmetric stable distributions

This paper reports on a simulation comparison of scale estimators for symmetric stable distributions in terms of their ability to identify the population with the greater scale. The modified geometric mean is found to be superior to the sample standard deviation and the Fama-Roll estimator for the larger values of the characteristic exponent, while the Fama-Roll estimator is judged superior for the smaller values. Further, this study sheds some light on the question of the appropriate sample size for discriminating risk measurement in investment analysis when the samples are taken from symmetric stable distributions.     

Some Related Minima Stability and Minima Infinite Divisibility of the General Multivariate Pareto Distributions

This article studies the minima stable property of the general multivariate Pareto distributions MP^(k)(I), MP^(k)(II), MP^(k)(III), MP^(k)(IV) which can be applied to characterize the MP^(k) distribution via its weighted ordered coordinates minima and marginal distribution. Also, the multivariate semi-Pareto distribution (denoted by MSP) is discerned in the class of geometric minima infinite divisible and geometric minima stable distributions. If the exponent measure is satisfied by some functional equation, then the geometric minima stable property can be used to characterize the MSP distribution. Finally, the finite sample minima infinite divisible property of the MP^(k)(I), (II), and (IV) distributions is also discussed.     

Minimum variance unbiased estimation in natural exponential families generated by stable distributions

The class of nature exponential families generated by stable distributions has been introduced in different contexts by several authors. Tweedie (1984) and Jorgensen (1987) studied this class in the context of generalized liner models and exponential dispersion models. Bar-Lev and Enis (1986) introduced this class in the context of the property of reproducibility in natural exponential families and Hougaard (1986) found the distributions in this class to be natural candidates for applications as survival distributions in life tables for heterogeneous populations. In this note, we consider such a class in the context of minimum variance unbiased estimation. For each family in this class, we obtain an explicit expression for the uniformly minimum variance unbiased estimator for the r-th cumlant, the density function, and the reliability function.     

The Self‐Similar and Multifractal Nature of a Network Traffic Model

Abstract

We look at a family of models for Internet traffic with increasing input rates and consider approximation models which exhibit self‐similarity at large time scales and multifractality at small time scales. Depending on whether the input rate is fast or slow, the total cumulative input traffic can be approximated by a self‐similar stable Lévy motion or a self‐similar Gaussian process. The stable Lévy limit does not depend on the behavior of the individual transmission schedules but the Gaussian limit does. Also, the models and their approximations show multifractal behavior at small time scales.     

A note on a strong renewal theorem

Let {S_n, n ≥ 1} be a sequence of partial sums of independent and identically distributed non-negative random variables with a common distribution function F. Let F belong to the domain of attraction of a stable law with exponent α, 0 < α < 1. Suppose H(t) = ? N(t), t ? 0, where N(t) = max(n : S_n ≥ t). Under some additional assumptions on F, the difference between H(t) and its asymptotic value as t → ∞ is estimated.