Minimum Hellinger distance estimators for multivariate distributions from the Johnson system

In this paper, we study minimum Hellinger distance estimators (MHDEs) for multivariate distributions from the Johnson system. We prove some properties of these estimators, such as consistency and asymptotic normality, and show that they represent a robust alternative for other existing estimators.     

评析约翰逊总统时期美国对华政策

约翰逊执政时期表面上美国对华仍然推行传统的遏制和封锁政策,但是实际上随着新的国内外局势的变动,美国原有对华政策的公共观念的一致性遭到破坏.要求改变对华政策的思想逐渐成为主流,而约翰逊政府也开始重新审视对华政策,特别是“遏制但不孤立政策”的提出,正是美国试图改变对华政策的一种努力。尽管这一时期美国对华政策在行动上没有实质性的突破,但却为尼克松政府实现重大调整做了思想和政策的充分准备。     

肯尼迪和约翰逊政府对西欧的经济政策

50年代末60年代初,西欧独立性增强,对美国的主导地位形成挑战。肯尼迪和约翰逊两届政府提出并实施了对西欧新的政策:建立伙伴关系的大西洋共同体。目的是将发展起来的西欧规制到美国主导的大西洋框架内。政策体现了美国门户开放的扩张方式和美国冷战战略的需要,并反映了美欧经济关系由依附趋向平等的走向。     

约翰逊政府时期美国的东西方贸易管制政策

通过对约翰逊政府的东西方贸易管制政策的考察,可以发现一方面美国的东西方贸易管制政策正逐渐从禁运战略物资转向限制高新技术转让,经济遏制的目的也逐渐从阻碍苏联集团国家战争潜力的增长向影响苏联集团的外交政策和国内政治转变,另一方面通过推行“中国差别”政策,继续阻碍中国现代化进程,这一政策使美国与西方盟国关系进一步恶化,美国为此付出沉重的代价。     

Modeling patient arrivals in community clinics

We develop improved methods for modeling and simulating the streams of patients arriving at a community clinic. In previous practice, random (unscheduled) patient arrivals were often assumed to follow an ordinary Poisson process (so the corresponding patient interarrival times were randomly sampled from an exponential distribution); and for scheduled arrivals, each patient's tardiness (i.e., the deviation from the scheduled appointment time) was often assumed to be randomly sampled from a normal distribution. A thorough analysis of patient arrival times, obtained from detailed workflow observations in nine community clinics, indicates these assumptions are not generally valid, and the tardiness data sets for this study are best modeled by unbounded Johnson distributions. We also propose a nonhomogeneous Poisson process to model the random patient arrivals; we review a nonparametric approach to estimating the associated mean-value function; and we describe an algorithm for generating random patient arrivals from the estimated model. The adequacy of this model of random patient arrivals can be assessed by standard goodness-of-fit tests. These findings are important since testable scheduling optimization strategies must be based upon accurate models for both random and scheduled patient arrivals. The impacts on modeling, as well as implications for practice management, are discussed.     

A test for the composite hypothesis that a population has a gamma distribution

A test of the composite hypothesis that a population has a gamma distribution is presented. The test is conducted by using a rank test of bivariate independence, such as the one .based on Kendallfs sample tau coefficient. The performance of the test is examined by means of a Monte Carlo study.     

Constrained Maximization of the Shapiro–Wilk W Statistic to Estimate Parameters of the Johnson S B Distribution

This article presents a constrained maximization of the Shapiro Wilk W statistic for estimating parameters of the Johnson S _B distribution. The gradient of the W statistic with respect to the minimum and range parameters is used within a quasi-Newton framework to achieve a fit for all four parameters. The method is evaluated with measures of bias and precision using pseudo-random samples from three different S _B populations. The population means were estimated with an average relative bias of less than 0.1% and the population standard deviations with less than 4.0% relative bias. The methodology appears promising as a tool for fitting this sometimes difficult distribution.     

On a variance stabilizing model and its application to genomic data

In this paper, we propose a model based on a class of symmetric distributions, which avoids the transformation of data, stabilizes the variance of the observations, and provides robust estimation of parameters and high flexibility for modeling different types of data. Probabilistic and statistical aspects of this new model are developed throughout the article, which include mathematical properties, estimation of parameters and inference. The obtained results are illustrated by means of real genomic data.     

约翰逊政府削减旅游逆差的尝试

旅游逆差是导致美国国际收支逆差的重要因素。为了改善美国国际收支状况,约翰逊政府对旅游政策进行了长期深入研究,推出了诸如降低美国公民出国旅游的关税豁免额、开展"浏览美国"等措施。这些措施在一定程度上抑制了美国旅游逆差的发展,但是并没有从根本上解决美国的旅游逆差问题。