A revisit to test the equality of variances of several populations

We revisit the problem of testing homoscedasticity (or, equality of variances) of several normal populations which has applications in many statistical analyses, including design of experiments. The standard text books and widely used statistical packages propose a few popular tests including Bartlett's test, Levene's test and a few adjustments of the latter. Apparently, the popularity of these tests have been based on limited simulation study carried out a few decades ago. The traditional tests, including the classical likelihood ratio test (LRT), are asymptotic in nature, and hence do not perform well for small sample sizes. In this paper we propose a simple parametric bootstrap (PB) modification of the LRT, and compare it against the other popular tests as well as their PB versions in terms of size and power. Our comprehensive simulation study bursts some popularly held myths about the commonly used tests and sheds some new light on this important problem. Though most popular statistical software/packages suggest using Bartlette's test, Levene's test, or modified Levene's test among a few others, our extensive simulation study, carried out under both the normal model as well as several non-normal models clearly shows that a PB version of the modified Levene's test (which does not use the F-distribution cut-off point as its critical value), and Loh's exact test are the “best” performers in terms of overall size as well as power.     

中国特色社会主义民主政治的内在优势和前景

所谓中国模式、中国奇迹,从表象来看是中国经济发展的奇迹,实际上其背后的支撑是中国政治制度的优势。中国经济奇迹的秘密在于我们的政治制度的有效性和优越性,他能组织和调动起八千多万党员和13亿人民的积极性和创造性;能为现代化目标做出长远规划,且能在动态中加以调整;能确保改革开放在和谐稳定的环境中逐步推进;有足够的组织上的激励去执行和维护经济发展的战略;能推动国家和社会的良性互动;为各级地方政府间互相竞争提供可持续的学习和创新平台;在面对国际国内危机时善于化危机为机遇。     

中越边境跨境非婚生子女的心理健康状况分析

采用问卷法,对中越边境地区跨境非婚生子女进行心理健康状况测查.结果表明,中越边境地区跨境非婚生子女总体心理健康水平低于国内其他一些中小学生群体,心理健康问题严重;女孩的恐怖倾向极其显著且高于男孩;中学生过敏倾向、对人焦虑显著高于小学生;父母是否外出打工对孩子心理健康的影响不显著;住校孩子的自责倾向、过敏倾向显著高于不住校的孩子;排行中间的孩子心理健康状况最差,排行对孩子自责倾向、身体症状影响显著.政府、学校要重视对这群特殊孩子的心理援助.     

论新时期电影中女性情欲的政治表述

在倡导生产伦理的主导政治的影响下，新时期电影中的女性情欲话语依然内含着某种变形后的政治动员机制，它们或以情欲展演完成政治神话的表述，或以情欲规划引导观众的利比多流向。然而，新时期电影所获得的半自律性生存空间，使得越轨的银幕女体情欲展演亦拥有其存活土壤，它们与主导政治文化之间既有共谋亦有背离。     

论高校学生团干部的素质及培养

学生团干部是高校共青团工作的主干力量,是各项学生活动的策划者、组织者和执行者.他们的素质高低直接关系到整个学校共青团工作的水平和质量.文章就高校学生团干部的四项素质进行了论述,并就其培养途径进行了探讨.     

电视相亲节目的同质化因素与异质性创新研究

作为一种为未婚男女提供电视相亲平台的节目类型，电视相亲节目不仅创造了收视奇迹，为两情相悦的男女嘉宾提供配对成功的良机，而且在中国当下社会文化语境中，还延伸到婚恋观念、个人价值、人际交往、家庭关系等话题，甚至涉及社会思想、文化等方面，成为中国电视文化50多年来的一个较有特色的节目类型。在一种比较研究的视野下，结合历史研究、作品研究、类型研究、文化研究等方式，研寻中国电视相亲节目的同质化与异质性，从而透析它们在产品定位、叙事规则、营销手段等方面表现出来的同质化倾向与差异性发展策略。     

基于SSL协议安全通信原理与实现

SSL(Secure Sockets Layer)是用于web的安全通信标准.被设计用来使用TCP时提供一个可靠的点到点安全服务,保证两个通讯个体之间的保密性和完整性.openssl是SSL的一份完整实现,内部包含了大量加密算法程序.文章介绍了SSL协议的工作原理,并使用openssl实现SSL协议的安全网络通信过程.     

Foot-and-Mouth Disease Entrance Assessment Model Through Air Passenger Violations

This article aims to construct a risk model for the prediction of foot-and-mouth disease (FMD) entrance caused by passengers who illegally carry meat products of cloven-hoofed animals through international airports into a country. The risk that meat contaminated with the FMD virus is formulated as the probabilities of FMD factor events (the prevalence of FMD), the commodity factor event (the transportation, storage, and distribution (TSD) factor event), and the passenger event. Data used for analysis were records of illegal meat product carriers from areas A and B intercepted at an international airport in Taiwan. A risk model was proposed to simulate the probability distributions in disease prevalence, probability of FMD virus existing in the meat products after meat processing, and estimation of survival of virus and time period for TSD. The probability of the passenger event was hypothesized with the odds of intercepted passengers and estimated via logistic regression. The results showed that the odds of passengers being intercepted by beagles were higher than those intercepted by Customs. By conducting Monte Carlo simulations, the probability of FMD virus risk caused by FMD factors from area A was 149 times lower than that from area B. The probability of FMD virus risk caused by the passenger event from area A was four times lower than the corresponding probability from area B. The model provides a contribution to FMD prevention and can be a reference for developing models of other diseases.     

中国短期跨境资本流动研究综述——途径、规模和影响因素

短期跨境资本,也可称为热钱或国际游资.在资本项目尚未完全开放的中国,其大规模流动一方面扰乱了我国宏观经济政策的制定与实施,另一方面威胁着我国的金融与经济安全.在东南亚金融危机时期以及当前的人民币升值时期,国内学界掀起了两场对于短期跨境资本流动的大讨论.其争论的焦点主要集中在流动途径、流动规模以及影响短期跨境资本流动的因素等方面.本文拟对诸观点进行深入评述.     

我国现阶段社会矛盾的特点及其解决途径

社会主义和谐社会是矛盾冲突发展的一种状态，应正视矛盾冲突在社会发展中的正向作用，建立民主法治框架下的利益表达平台，掌握互联网时代社会矛盾冲突特点，立足于矛盾的对立统一辩证思维，以妥协为基本方法化解矛盾冲突，实现社会稳定发展。