Testing equality of correlation coefficients for paired binary data from multiple groups

Paired binary data arise naturally when paired body parts are investigated in clinical trials. One of the widely used models for dealing with this kind of data is the equal correlation coefficients model. Before using this model, it is necessary to test whether the correlation coefficients in each group are actually equal. In this paper, three test statistics (likelihood ratio test, Wald-type test, and Score test) are derived for this purpose. The simulation results show that the Score test statistic maintains type I error rate and has satisfactory power, and therefore is recommended among the three methods. The likelihood ratio test is over conservative in most cases, and the Wald-type statistic is not robust with respect to empirical type I error. Three real examples, including a multi-centre Phase II double-blind placebo randomized controlled trial, are given to illustrate the three proposed test statistics.     

C131. Determining the noncentral wishart characteristic function via quadratic expressions

A Critic's Guide to Software for CP/M Computers, ISBN 0-8019-7404-6. A Critic's Guide to Software for IBM-PC and PC-Compatible Computers, ISBN 0-8091-7413-5. A Critic's Guide to Software for Apple and Apple-Compatible Computers, ISBN 0-8091-7412-7 by Phillip I, Good, ph. D. Prienred and distributed by: Chilton Company Radnor, Pennsylvania 19089 1983 - $ per volume     

Estimation of semi-varying coefficient models with nonstationary regressors

We study a semivarying coefficient model where the regressors are generated by the multivariate unit root I(1) processes. The influence of the explanatory vectors on the response variable satisfies the semiparametric partially linear structure with the nonlinear component being functional coefficients. A semiparametric estimation methodology with the first-stage local polynomial smoothing is applied to estimate both the constant coefficients in the linear component and the functional coefficients in the nonlinear component. The asymptotic distribution theory for the proposed semiparametric estimators is established under some mild conditions, from which both the parametric and nonparametric estimators are shown to enjoy the well-known super-consistency property. Furthermore, a simulation study is conducted to investigate the finite sample performance of the developed methodology and results.     

复合指数函数泰勒系数之不等式

本文目的在综合叙述及推导复合指数函数的幂级数之系数间相关不等式．其特殊情形为Milin和lebejev首先证明，在单叶函数理论起着非常重要的作用．在此我们完全摆脱单叶函数关系叙述．     

Not the First Digit! Using Benford's Law to Detect Fraudulent Scientif ic Data

Digits in statistical data produced by natural or social processes are often distributed in a manner described by ‘Benford's law’. Recently, a test against this distribution was used to identify fraudulent accounting data. This test is based on the supposition that first, second, third, and other digits in real data follow the Benford distribution while the digits in fabricated data do not. Is it possible to apply Benford tests to detect fabricated or falsified scientific data as well as fraudulent financial data? We approached this question in two ways. First, we examined the use of the Benford distribution as a standard by checking the frequencies of the nine possible first and ten possible second digits in published statistical estimates. Second, we conducted experiments in which subjects were asked to fabricate statistical estimates (regression coefficients). The digits in these experimental data were scrutinized for possible deviations from the Benford distribution. There were two main findings. First, both digits of the published regression coefficients were approximately Benford distributed or at least followed a pattern of monotonic decline. Second, the experimental results yielded new insights into the strengths and weaknesses of Benford tests. Surprisingly, first digits of faked data also exhibited a pattern of monotonic decline, while second, third, and fourth digits were distributed less in accordance with Benford's law. At least in the case of regression coefficients, there were indications that checks for digit-preference anomalies should focus less on the first (i.e. leftmost) and more on later digits.     

A SELECTED BIBLIOGRAPHY ON THE ANALYSIS OF REPEATED MEASUREMENTS and RELATED AREAS

Different approaches to the analysis of repeated measurements are outlined. For each approach, a few key references are given as a possible basis for further reading. Related methodological areas are mentioned, again accompanied by key references in each case.     

Optimum invariant tests on discriminant coefficients or means of multinormal population with additional information

Some optimum invariant tests are derived for certain hypotheses on discriminant coefficients or means when some extra observations are available on some components of a random vector X, which is distributed as N(μ,Σ), where μ and Σ are unknown.     

区间直觉模糊数环境下基于犹豫度和相关系数的多属性群决策模型研究

多属性群决策问题是当今复杂决策环境下的研究热点,而区间直觉模糊数可以从隶属度、非隶属度和犹豫度三方面描述不确定信息,具有很强的表现能力,因此学界基于区间直觉模糊数对多属性群决策问题进行了大量研究。但是现有研究一方面在处理共识达成问题时所广泛采用的"多数原则"策略会导致某些关键信息或知识被视为冲突意见而被修改或忽视;另一方面基于距离的区间直觉模糊数相似性测算方法忽略了犹豫度的影响,会造成评价信息损失。针对上述不足,提出区间直觉模糊数环境下基于犹豫度和相关系数的多属性群决策模型。首先,通过个体犹豫度和群体犹豫度的提出,保证了决策群体内部信息和知识的有效交流,使关键性决策信息或知识不会通过强制修改或删除的方式失效;其次,采用区间直觉模糊数相关系数测量相似度,避免基于距离测算而可能出现的错误结果;继而,将决策主体权重设置为区间直觉模糊数形式,通过计算不同决策者之间的相对优势值和劣势值进行主观赋值,保证了决策者权重的客观性和真实性;此外,结合TOPSIS和线性规划方法求解得到最优属性权重,保证了属性赋值的精确性,最后,通过具体的应用实例以及与当前学界主要研究成果的比较分析,进一步论证了所提模型的优势和创新性。     

Count data and treatment heterogeneity in 2×2 crossover trials

Count data are routinely assumed to have a Poisson distribution, especially when there are no straightforward diagnostic procedures for checking this assumption. We reanalyse two data sets from crossover trials of treatments for angina pectoris , in which the outcomes are counts of anginal attacks. Standard analyses focus on treatment effects, averaged over subjects; we are also interested in the dispersion of these effects (treatment heterogeneity). We set up a log-Poisson model with random coefficients to estimate the distribution of the treatment effects and show that the analysis is very sensitive to the distributional assumption; the population variance of the treatment effects is confounded with the (variance) function that relates the conditional variance of the outcomes, given the subject's rate of attacks, to the conditional mean. Diagnostic model checks based on resampling from the fitted distribution indicate that the default choice of the Poisson distribution for the analysed data sets is poorly supported. We propose to augment the data sets with observations of the counts, made possibly outside the clinical setting, so that the conditional distribution of the counts could be established.     

产业关联视角下北京市交通运输业经济效应测算研究

交通运输业对国民经济的带动效应源于两个方面,一是交通运输业本身发展对经济所产生的直接经济效应,二是交通运输业发展带动相关产业发展对经济所产生的间接经济效应.文章以关联系数描述了交通运输业与其相关产业的关联关系,并运用关联系数、增长值贡献率模型,测度了北京市交通运输业对国民经济的拉动和推动效应.研究认为,任何一个产业经济效应的大小不仅取决于其直接经济效应,也取决于其间接经济效应.经济效应的大小取决于其在产业链中的位置、与其他支柱产业的关联程度和与其他支柱产业的产业距离.产业位置靠前,其拉动效应小于推动效应,产业位置靠后,其拉动效应大于推动效应.交通运输业作为基础产业,其产业位置相对靠前,其前向推动效应大于其后向拉动效应.