An approximation of logarithmic functions in the regression setting

We consider a method of moments approach for dealing with censoring at zero for data expressed in levels when researchers would like to take logarithms. A Box–Cox transformation is employed. We explore this approach in the context of linear regression where both dependent and independent variables are censored. We contrast this method to two others, (1) dropping records of data containing censored values and (2) assuming normality for censored observations and the residuals in the model. Across the methods considered, where researchers are interested primarily in the slope parameter, estimation bias is consistently reduced using the method of moments approach.     

Computing maximum likelihood estimates from type II doubly censored exponential data

It is well-known that, under Type II double censoring, the maximum likelihood (ML) estimators of the location and scale parameters, θ and δ, of a twoparameter exponential distribution are linear functions of the order statistics. In contrast, when θ is known, theML estimator of δ does not admit a closed form expression. It is shown, however, that theML estimator of the scale parameter exists and is unique. Moreover, it has good large-sample properties. In addition, sharp lower and upper bounds for this estimator are provided, which can serve as starting points for iterative interpolation methods such as regula falsi. Explicit expressions for the expected Fisher information and Cramér-Rao lower bound are also derived. In the Bayesian context, assuming an inverted gamma prior on δ, the uniqueness, boundedness and asymptotics of the highest posterior density estimator of δ can be deduced in a similar way. Finally, an illustrative example is included.     

变换法在解微分方程中的应用

变量代换法是解常微分方程的一种辅助方法，它能使问题简化．本文通过联系实例给出了变换在求解微分方程中的具体应用。     

用Excel统计数值型数据频数分布的三种方法

本文根据两种不同的数据分组方式,分别讨论了利用Excel软件统计数值型数据频数分布的三种基本方法并作了简要评述。     

浅探交际教学法和语法教学法在英语教学中的结合

通过分析交际教学法和语法教学法自身的特点和各自在英语教学中的优势与局限 ,指出将两者结合应用应是现阶段大学英语教学最理想的教学模式 ,并从教学目的、教学对象和教师自身角度说明了这种结合应用的必要性。在此基础上 ,总结了目前在结合应用实践中发现的问题 ,并提出了相应的解决办法。     

香山“长庆”有遗篇——试论《长恨歌》与《圆圆曲》的黍离之感

梅村体是长庆体的变格,但其中都充满着浓烈的黍离麦秀之感,所不同者在于一为乱世之音,一为亡国之音.诗人感伤兴寄,作垂戒之用.     

创作方法:文学理论不该遗弃的概念

创作方法概念不该遗弃,而应重新认识其内涵和层次。本文认为,创作方法包括三个基本要素,即创作目的、创作对象和创作原则。具体创作对象的差异以及三要素的不同组合方式使得创作方法具有无限丰富的形态。风格的多样反映了创作方法的多样。以这种新的创作方法概念,可以对许多纠缠不清的问题,如创作方法与世界观、文艺思潮及风格流派的关系问题等,作出新的解释。     

教育技术系统方法在幼儿教育中的应用个案

运用教育技术系统方法开展教学活动,对于幼儿教育同样适用,在幼儿教育中使用系统方法,整合信息技术,让幼儿从小接受多角度、全方位的思维训练。现以一次成功运用系统方法的幼教实践活动作为案例,提取其中的主要步骤进行分析,抛出幼儿教育推广系统方法之砖。     

Accelerated life test sampling plans for the Weibull distribution under Type I progressive interval censoring with random removals

This paper considers the design of accelerated life test (ALT) sampling plans under Type I progressive interval censoring with random removals. We assume that the lifetime of products follows a Weibull distribution. Two levels of constant stress higher than the use condition are used. The sample size and the acceptability constant that satisfy given levels of producer's risk and consumer's risk are found. In particular, the optimal stress level and the allocation proportion are obtained by minimizing the generalized asymptotic variance of the maximum likelihood estimators of the model parameters. Furthermore, for validation purposes, a Monte Carlo simulation is conducted to assess the true probability of acceptance for the derived sampling plans.     

A goodness of fit test for the multilevel proportional odds model

It is essential to test the goodness of fit of the model before making inferences based on it. Multilevel modeling of ordinal categorical responses is not as developed as for continuous responses. Assessing model adequacy in terms of the goodness of fit with ordinal categorical responses is still being developed and no satisfactory tests are available so far. As a consequence of that, this study concentrates on developing such a goodness of fit test for Multilevel Proportional Odds models and to study the properties of the test.