Complete consistency for the estimator of nonparametric regression model based on martingale difference errors

Abstract

In this paper, we study the complete consistency for the estimator of nonparametric regression model based on martingale difference errors, and obtain the convergence rates of the complete consistency by using the inequalities for martingale difference sequence. Finally, some simulations are illustrated.     

Detecting Variance Change-Points for Blocked Time Series and Dependent Panel Data

This article proposes a class of weighted differences of averages (WDA) statistics to test and estimate possible change-points in variance for time series with weakly dependent blocks and dependent panel data without specific distributional assumptions. We derive the asymptotic distributions of the test statistics for testing the existence of a single variance change-point under the null and local alternatives. We also study the consistency of the change-point estimator. Within the proposed class of the WDA test statistics, a standardized WDA test is shown to have the best consistency rate and is recommended for practical use. An iterative binary searching procedure is suggested for estimating the locations of possible multiple change-points in variance, whose consistency is also established. Simulation studies are conducted to compare detection power and number of wrong rejections of the proposed procedure to that of a cumulative sum (CUSUM) based test and a likelihood ratio-based test. Finally, we apply the proposed method to a stock index dataset and an unemployment rate dataset. Supplementary materials for this article are available online.     

《机械制图》新国标和国际标准的差异性分析

《机械制图》国家标准是绘制机械图样的依据。本文简述了《机械制图》国标的发展过程、新国标与国际标准的差异以及国人执行新国标的现状,指出为了整体提高机械行业的技术水平,保证产品质量,逐渐缩短和发达国家的差距,就必须认真贯彻和执行新的国家标准。并阐述了向国际标准发展的必然趋势及推广新国标的意义。     

Covariance and variance evaluations of two estimators for drug–placebo difference in a trial with sequential parallel design

Chen et al. [Contemp. Clin. Trials, 32: 592–604 (2011)] heuristically proved that the covariance of two estimators is zero assuming equal correlation coefficients. In this article, the above covariance is analytically and rigorously re-derived without any strong assumption in equality between two correlation coefficients. Under rigorous analytic derivations plus assuming number of subjects continuing into Period 2 is a random variable, covariance is reconfirmed to be zero for both normal and binomial data.     

A Probabilistic Approach to Assess External Doses to the Public Considering Spatial Variability of Radioactive Contamination and Interpopulation Differences in Behavior Pattern

Dose assessment is an important issue from the viewpoints of protecting people from radiation exposure and managing postaccident situations adequately. However, the radiation doses received by people cannot be determined with complete accuracy because of the uncertainties and the variability associated with any process of defining individual characteristics and in the dose assessment process itself. In this study, a dose assessment model was developed based on measurements and surveys of individual doses and relevant contributors (i.e., ambient dose rates and behavior patterns) in Fukushima City for four population groups: Fukushima City Office staff, Senior Citizens’ Club, Contractors’ Association, and Agricultural Cooperative. In addition, probabilistic assessments were performed for these population groups by considering the spatial variability of contamination and interpopulation differences resulting from behavior patterns. As a result of comparison with the actual measurements, the assessment results for participants from the Fukushima City Office agreed with the measured values, thereby validating the model and the approach. Although the assessment results obtained for the Senior Citizens’ Club and the Agricultural Cooperative differ partly from the measured values, by addressing further considerations in terms of dose reduction effects due to decontamination and the impact of additional exposure sources in agricultural fields, these results can be improved. By contrast, the measurements obtained for the participants from the Contractors’ Association were not reproduced well in the present study. To assess the doses to this group, further investigations of association members’ work activities and the related dose reduction effects are needed.     

Enhanced adaptive CUSUM charts for process mean

A statistical quality control chart is an important tool of the statistical process control, which is widely used to control and monitor a production process. The CUSUM chart is designed to detect a specific shift, provided that the shift size is known in advance. In practice, however, shift sizes are rarely known. It is then customary to use an adaptive CUSUM chart, which can effectively detect a range of shift sizes. In this paper, we enhance the sensitivities of the improved adaptive CUSUM mean charts using an auxiliary-information-based (AIB) mean estimator. The run length performances of the proposed charts are compared with those of the AIB adaptive and non-adaptive CUSUM charts in terms of the average run length (ARL), extra quadratic loss, and integral relative ARL. These run length comparisons reveal that the proposed charts are more sensitive than the existing charts when detecting different kinds of shift in the process mean. An example is given to demonstrate the implementation of existing and proposed charts.     

The politics of identity: from potential to pitfalls,and symbols to substance

In this public lecture to mark the 25th anniversary of Identities: Global Studies in Culture and Power, award-winning Guardian journalist and author Gary Younge reflects on the potentialities, ambivalences and challenges of ‘identity’ as a basis for political action in the contemporary climate.     

麦尔维尔作品中的重复艺术

重复是文学作品中常见的现象,解剖重复的含义是理解小说整体内容的一个重要途径。麦尔维尔的作品带有明显的重复现象,重复同一性和差异性的特点恰恰彰显了其社会、种族、宗教、人性等主题的多样化,在不同的文学背景中呈现出的意义也不同,而这正是真正文学作品的艺术魅力所在。     

The power of difference in inclusive research

Inclusive research involves people with intellectual disabilities actively and strives for empowerment and normalisation. Less is written about the power dynamics in a research team consisting of researchers and people with intellectual disabilities and the possible value of such collaboration. In this auto-ethnography we reflect on these aspects and the challenges along the way. We conclude that striving for normalisation can be paralysing; ‘doing the same’ is not always possible and can be disempowering for all members of the research team. Acknowledging differences and uniqueness enriches research outcomes and makes us reflect on our own, sometimes rigid, academic frameworks.     

连续刚构桥合龙顶推力优化计算方法

预应力砼连续刚构桥因其施工简单、造价经济、受力合理、行车舒适等优势迅速发展,但成桥后混凝土收缩、徐变及温度变化将对连续刚构桥主梁和桥墩的变形及内力产生较大影响.结合州河大桥工程实例,充分考虑确定顶推力的主要因素,对连续刚构桥合龙前顶推量取值进行研究.结果表明,合理的顶推力能显著地改善桥墩的受力.