Tests for time series of counts based on the probability-generating function

We propose testing procedures for the hypothesis that a given set of discrete observations may be formulated as a particular time series of counts with a specific conditional law. The new test statistics incorporate the empirical probability-generating function computed from the observations. Special emphasis is given to the popular models of integer autoregression and Poisson autoregression. The asymptotic properties of the proposed test statistics are studied under the null hypothesis as well as under alternatives. A Monte Carlo power study on bootstrap versions of the new methods is included as well as real-data examples.     

Empirical Non-Parametric Control Charts: Estimation Effects and Corrections

Owing to the extreme quantiles involved, standard control charts are very sensitive to the effects of parameter estimation and non-normality. More general parametric charts have been devised to deal with the latter complication and corrections have been derived to compensate for the estimation step, both under normal and parametric models. The resulting procedures offer a satisfactory solution over a broad range of underlying distributions. However, situations do occur where even such a large model is inadequate and nothing remains but to consider non- parametric charts. In principle, these form ideal solutions, but the problem is that huge sample sizes are required for the estimation step. Otherwise the resulting stochastic error is so large that the chart is very unstable, a disadvantage that seems to outweigh the advantage of avoiding the model error from the parametric case. Here we analyse under what conditions non-parametric charts actually become feasible alternatives for their parametric counterparts. In particular, corrected versions are suggested for which a possible change point is reached at sample sizes that are markedly less huge (but still larger than the customary range). These corrections serve to control the behaviour during in-control (markedly wrong outcomes of the estimates only occur sufficiently rarely). The price for this protection will clearly be some loss of detection power during out-of-control. A change point comes in view as soon as this loss can be made sufficiently small.     

理论实证相印语言文化相融--胡正武《训诂阐微集》评议

胡正武新著《训诂阐微集》在训诂方面所展现的,具有理论与实证相得益彰,语言与文化水乳交融,语料丰富内容广博等特点,这是与其深厚扎实的学术功底,别具一格的研究方法相为表里的。胡君甘于寂寞的治学态度,该书朴实无华的语言风格在当今急功近利、充满躁动的商品经济社会里,尤其显示其现实意义。     

BAYESIAN SUBSET SELECTION AND MODEL AVERAGING USING A CENTRED AND DISPERSED PRIOR FOR THE ERROR VARIANCE

This article proposes a new data‐based prior distribution for the error variance in a Gaussian linear regression model, when the model is used for Bayesian variable selection and model averaging. For a given subset of variables in the model, this prior has a mode that is an unbiased estimator of the error variance but is suitably dispersed to make it uninformative relative to the marginal likelihood. The advantage of this empirical Bayes prior for the error variance is that it is centred and dispersed sensibly and avoids the arbitrary specification of hyperparameters. The performance of the new prior is compared to that of a prior proposed previously in the literature using several simulated examples and two loss functions. For each example our paper also reports results for the model that orthogonalizes the predictor variables before performing subset selection. A real example is also investigated. The empirical results suggest that for both the simulated and real data, the performance of the estimators based on the prior proposed in our article compares favourably with that of a prior used previously in the literature.     

Semi-parametric estimation of ROC curves based on binomial regression modelling

This paper presents a method of estimating a receiver operating characteristic (ROC) curve when the underlying diagnostic variable X is continuous and fully observed. The new method is based on modelling the probability of response given X , rather than the distribution of X given response. The method offers advantages in modelling flexibility and computational simplicity. The resulting ROC curve estimates are semi-parametric and can, in principle, take an infinite variety of shapes. Moreover, model selection can be based on standard methods within the binomial regression framework. Statistical accuracy of the curve estimate is provided by a simply implemented bootstrap approach.     

西部经理人激励约束机制现状调查与实证分析--以西安市中小企业为例

运用调查问卷的方法,对西安市中小企业激励约束机制的现状、满意度、现存问题和影响因素等方面进行调研并做出了相关性分析,结果表明(1)西安市中高层管理人员对现有的激励机制不满意;(2)独立董事制度并没有起到相应的监督作用;(3)组织机构层次与信息的变失程度呈强的线性相关性.提出了建立健全信道系统,将激励约机制与市场环境相适应,重视经营者股权激励等方面的建议.     

二语词汇语义迁移证明——两个实验方法比较

本文本文先简述了二语词汇表征和发展模式，此模式明确展示了二语词汇习得的过程和阶段。再从实验方法上对两个实验进行了比较，试图在二语词汇表征实证研究上并且在复制研究上给研究者们以启示。     

中国产业结构变动与就业水平的实证研究

文章运用时间序列和计量模型研究了中国产业结构与就业水平之间的发展关系.首先运用格兰杰因果检验分析了第一、二、三次产业的产值与其就业之间的因果影响关系,继而从产值与就业两个角度定量分析了第一、二、三次产业各自对总就业水平的贡献,得出结论:第一产业和第三产业是劳动力就业的决定因素,而第二产业不是就业的决定因素;从产值角度来看,第三产业对劳动力就业的贡献最大,从就业角度来看,第一产业的就业对总体就业水平的贡献最高,其次是第三产业,而第二产业的就业对总体就业水平的贡献最小.最后根据研究结论提出相应的建议措施.     

合伙律师事务所的管理模式创新——结合贝克·麦肯思律师事务所的实证分析

合伙律师事务所是一个复杂且特殊的组织,其管理水平超过对企业的管理水平,因此更需要创新管理,以真正实现现代化、国际化、规模化和品牌化。本文从比较我国合伙律师事务所管理模式的发展阶段着手,分析了不同阶段和不同管理模式的优缺点;继而提出构建杠铃管理的新模式,对合伙律师事务所进行有效管理,即重点抓好品牌管理和人本管理,结合贝克.麦肯思律师事务所的成功管理经验进行实证分析。