A uniform saddlepoint expansion for the null‐distribution of the wilcoxon‐mann‐whitney statistic

The authors give the exact coefficient of 1/N in a saddlepoint approximation to the Wilcoxon‐Mann‐Whitney null‐distribution. This saddlepoint approximation is obtained from an Edgeworth approximation to the exponentially tilted distribution. Moreover, the rate of convergence of the relative error is uniformly of order O (1/N) in a large deviation interval as defined in Feller (1971). The proposed method for computing the coefficient of 1/N can be used to obtain the exact coefficients of 1/Nⁱ, for any i. The exact formulas for the cumulant generating function and the cumulants, needed for these results, are those of van Dantzig (1947‐1950).     

Rate of convergence for the distribution of the spearman-karber estimator

A Berry-Esseen type of bound is obtained for the error of the normal approximation to the distribution of the Spearman-Karber estimator. It is shown that this bound is of the order of the square root of the common dose mesh.     

On unbiased estimation of gini index and yntema-pietra index of lognormal distribution and their variances

Here we derive the uniformly minimum variance unbiased (best) estimator and a strongly consistent, asymptotically normal, unbiased estimator of each of Gini index and Yntema-Pietra index of lognormal distribution . These estimators are in terms of generalized hypergeometric functions ₁F₂. Further, the variances of these estimators and the best estimators of variances of best estimators are found out. They are in terms of Kempé de Fériet's hypergeometric functions.     

Stochastic Learning Dynamics and Speed of Convergence in Population Games

We study how long it takes for large populations of interacting agents to come close to Nash equilibrium when they adapt their behavior using a stochastic better reply dynamic. Prior work considers this question mainly for 2 × 2 games and potential games; here we characterize convergence times for general weakly acyclic games, including coordination games, dominance solvable games, games with strategic complementarities, potential games, and many others with applications in economics, biology, and distributed control. If players' better replies are governed by idiosyncratic shocks, the convergence time can grow exponentially in the population size; moreover, this is true even in games with very simple payoff structures. However, if their responses are sufficiently correlated due to aggregate shocks, the convergence time is greatly accelerated; in fact, it is bounded for all sufficiently large populations. We provide explicit bounds on the speed of convergence as a function of key structural parameters including the number of strategies, the length of the better reply paths, the extent to which players can influence the payoffs of others, and the desired degree of approximation to Nash equilibrium.     

旅游产业与文化产业融合的动力系统研究

旅游与文化具有共同的融合基因,旅游产业与文化产业融合的动力机制与融合路径是指导两者融合的重要理论基础.从产业融合的推力、拉力、支持力和阻力四个层面构建旅游产业与文化产业融合的动力模型,并依照旅游和文化双方经营主体在跨界资源重组中的角色与融合深度,提出旅游产业与文化产业融合的四种路径:整合融合、吸纳融合、渗透融合和重组融合.     

Efficient Estimation of the Partly Linear Additive Hazards Model with Current Status Data

This paper focuses on efficient estimation, optimal rates of convergence and effective algorithms in the partly linear additive hazards regression model with current status data. We use polynomial splines to estimate both cumulative baseline hazard function with monotonicity constraint and nonparametric regression functions with no such constraint. We propose a simultaneous sieve maximum likelihood estimation for regression parameters and nuisance parameters and show that the resultant estimator of regression parameter vector is asymptotically normal and achieves the semiparametric information bound. In addition, we show that rates of convergence for the estimators of nonparametric functions are optimal. We implement the proposed estimation through a backfitting algorithm on generalized linear models. We conduct simulation studies to examine the finite‐sample performance of the proposed estimation method and present an analysis of renal function recovery data for illustration.     

转型时期中国经济增长的地区差异与收敛性分析

通过对1978~2004年中国地区经济发展的分析认为,20世纪90年代以来,我国省际经济发展差距有扩大的趋势,并且,形成了以东、中、西部为界的显著“收敛俱乐部”现象。本文以新古典收敛模型为框架,对转型时期各省区的经济发展进行计量分析,得出了条件收敛的结论。     

三网融合背景下高校图书馆的信息服务拓展

三网融合使高校图书馆服务平台增多、服务用户增加、服务内容复杂化。高校图书馆应充分利用三网融合带来的广阔平台,提供个性化服务、设立博客或微博、优化图书馆论坛和为农村提供服务等措施来拓展图书馆信息服务。     

新媒介环境下新闻采写课程改革研究

目前新媒体对新闻采写的冲击主要来自两个方面:媒介融合的加速和移动互联网的崛起。媒介融合要求新闻采写课必须打破过去课程设置过窄、教学方法单一的困境,培养学生跨媒介的思维能力和一专多能的报道技能。移动互联网的崛起要求新闻采写课在培养学生政治敏感、宣传意识的同时,应加大受众意识、服务意识方面的训练,不断增强新闻报道的可读性和公信力;此外采写课还应培养学生在移动互联网上获取信息、创作"微"新闻的能力,为他们将来的新闻报道工作打下坚实的基础。     

Non-parametric Estimation of a Survival Function with Two-stage Design Studies

Abstract.  The two-stage design is popular in epidemiology studies and clinical trials due to its cost effectiveness. Typically, the first stage sample contains cheaper and possibly biased information, while the second stage validation sample consists of a subset of subjects with accurate and complete information. In this paper, we study estimation of a survival function with right-censored survival data from a two-stage design. A non-parametric estimator is derived by combining data from both stages. We also study its large sample properties and derive pointwise and simultaneous confidence intervals for the survival function. The proposed estimator effectively reduces the variance and finite-sample bias of the Kaplan–Meier estimator solely based on the second stage validation sample. Finally, we apply our method to a real data set from a medical device postmarketing surveillance study.