Testing for a change point in a sequence of exponential random variables with repeated values

Two test statistics are proposed for the change-point problem with repeated values when the data follow an exponential distribution. The properties of these two statistics have been studied and their asymptotic distributions under the alternative have been derived. The powers of the two test statistics are compared. Real-data examples are presented to illustrate the application of these tests.     

Sensitivity Analysis Using Risk Measures

In a quantitative model with uncertain inputs, the uncertainty of the output can be summarized by a risk measure. We propose a sensitivity analysis method based on derivatives of the output risk measure, in the direction of model inputs. This produces a global sensitivity measure, explicitly linking sensitivity and uncertainty analyses. We focus on the case of distortion risk measures, defined as weighted averages of output percentiles, and prove a representation of the sensitivity measure that can be evaluated on a Monte Carlo sample, as a weighted average of gradients over the input space. When the analytical model is unknown or hard to work with, nonparametric techniques are used for gradient estimation. This process is demonstrated through the example of a nonlinear insurance loss model. Furthermore, the proposed framework is extended in order to measure sensitivity to constant model parameters, uncertain statistical parameters, and random factors driving dependence between model inputs.     

地方高校学困生帮扶现状分析及对策

深入贯彻落实十九大精神，打赢教育战线上的脱贫攻坚战，实施帮扶确保学业困难学生顺利完成学业是每一位教育工作者义不容辞的责任。文章采取问卷调查和访谈相结合的方法对SL学院400名学业困难学生帮扶现状进行了调查，结果显示：学困生帮扶意愿强烈，倾向于向朋辈求助；学困生认为学校已经开展的帮扶很有必要，但效果有待于进一步提高；辅导员作为学校学困生帮扶的主要人员，对学生的帮扶深度不够，效果欠佳，亟待提出相应对策提升帮扶效果，帮助学困生顺利脱困。     

Measurement of the subjective work environment

Abstract

This paper considers the various issues that frame the development and use of measures of the subjective work environment. It begins by questioning the role of the work environment in determining occupational health, and explores the possible mechanisms by which that environment might exert its influence. It concludes that one of the important final common pathways is psycho-physiological in nature, and is rooted in individual perception and cognition and the experience of stress. Important for this model are the concepts of mediation and moderation. The measurement of the subjective work environment has often been idiosyncratic to the study in hand, and there are few well-established measures in common use. It is argued that researchers should be careful when deciding not to use established measures and effectively ‘invent’ their own. In developing new measures, decisions have to be made concerning the nature of the measure along with its ‘granularity’ and complexity. It is also argued that it is important that researchers should follow good psychometric practice in the development of those measures. Suggestions for ‘good practice’ are discussed. Attention is drawn to the issues of reliability and validity, and this paper discusses the role of triangulation in the planning and execution of data collection and analysis. The paper ends by reviewing the recommendations made towards the development and use of measures of the subjective work environment.     

The Detection of Influential Observations for Allocation,Separation, and the Determination of Probabilities in a Bayesian Framework

Normal theory separation and allocation problems are discussed from a predictive point of view. Influence statistics are defined and employed to ascertain the impact that particular observations will have on the inferential goals—allocation of future observations, separation between populations, and the determination of probabilities for future cases. Methods are illustrated on a collection of financial data taken from Johnson and Wichern (1982).     

元末顺帝时期“三农”问题研究

元末顺帝时期,政治腐败,＂三农＂问题突出,主要体现在农民生活困苦、农业生产落后、农村管理混乱、村社组织涣散等方面,腐败不堪的政府施政失败,导致了＂三农＂的相关政策执行不力,给当时的社会造成了严重影响,直接导致了元末经济的崩溃,同时激发了社会阶级矛盾和民族矛盾,加速了元朝的覆灭,还对明初的相关政策措施产生了深远的影响。     

关于实施非物质文化遗产保护工程的若干思考

非物质文化遗产的衰落是必然的,要做好保护工作,就要发掘其自身的生长要素,从而采取相宜的措施。这些措施主要有提高民众的自觉意识、实现可能的功能转换、政府的重视和支持等几个方面。实施非物质文化遗产保护工程,要防止只做“搭台”的角色、搞“官员工程”、脱离群众、不看对象搞“一刀切”、过度开发和文化造假。     

Some maximum-indifference estimators for the slope of a univariate linear model

As known, the least-squares estimator of the slope of a univariate linear model sets to zero the covariance between the regression residuals and the values of the explanatory variable. To prevent the estimation process from being influenced by outliers, which can be theoretically modelled by a heavy-tailed distribution for the error term, one can substitute covariance with some robust measures of association, for example Kendall's tau in the popular Theil–Sen estimator. In a scarcely known Italian paper, Cifarelli [(1978), ‘La Stima del Coefficiente di Regressione Mediante l'Indice di Cograduazione di Gini’, Rivista di matematica per le scienze economiche e sociali, 1, 7–38. A translation into English is available at http://arxiv.org/abs/1411.4809 and will appear in Decisions in Economics and Finance] shows that a gain of efficiency can be obtained by using Gini's cograduation index instead of Kendall's tau. This paper introduces a new estimator, derived from another association measure recently proposed. Such a measure is strongly related to Gini's cograduation index, as they are both built to vanish in the general framework of indifference. The newly proposed estimator is shown to be unbiased and asymptotically normally distributed. Moreover, all considered estimators are compared via their asymptotic relative efficiency and a small simulation study. Finally, some indications about the performance of the considered estimators in the presence of contaminated normal data are provided.     

环境法执法机制研究

随着我国环境法立法体系的日益完善,加强环境执法已成为当前环境保护领域的焦点和难点问题。本文在分析了环境行政执法存在的问题及完善对策后,提出环境刑事执法的健全应以程序机制的完善为中心,并认为应从扩张民事诉讼主体资格和建立中立环境损害鉴定机构两个角度去完善当前的环境民事执法机制。     

Evaluating social investment in disability policy

Disability policy in European countries is displaying a shift towards social investment: increasing human capital and access to the labour market. The reasoning that underlies this transition is that disabled persons would benefit from mainstream employment, but are impeded in traditional policy by deficiencies in labour supply and demand. However, the shift towards more activating policies in many countries is accompanied by a decline in social protection. It is unclear whether social investment may effectively promote the employment chances of disabled persons within this context. The present research examines this question through a quantitative, cross-sectional, multilevel analysis on microdata from 22 EU countries. Our findings suggest greater activation to predict lower employment chances, while reducing passive support shows mixed effects. Conversely, measures for facilitation in daily life predict greater employment chances, as do measures for sheltered work. These findings raise questions over the value of social investment for disabled persons—and underline the need to overcome broader barriers in the labour market and in society.