SIMPCA: a framework for rotating and sparsifying principal components

We propose an algorithmic framework for computing sparse components from rotated principal components. This methodology, called SIMPCA, is useful to replace the unreliable practice of ignoring small coefficients of rotated components when interpreting them. The algorithm computes genuinely sparse components by projecting rotated principal components onto subsets of variables. The so simplified components are highly correlated with the corresponding components. By choosing different simplification strategies different sparse solutions can be obtained which can be used to compare alternative interpretations of the principal components. We give some examples of how effective simplified solutions can be achieved with SIMPCA using some publicly available data sets.     

Economic design of acceptance sampling plans for truncated life test using Frechet distribution

In this article designing of acceptance sampling plans for the truncated life test is proposed using economic approach by assuming that the lifetime of a product follows Frechet distribution based on median. The optimal sampling plans to meet the consumer’s confidence level with minimum total cost are designed. Efficiency of the proposed plan is also analyzed.     

“为”的语法化考察

从词义、句法位置、重新分析三个方面对“为”的语法化过程进行考察，可以发现，“为”的语法化是“为动”双宾语句消失的主要原因。动词“为”在词义泛化的基础上，由于句法位置和组合功能的变化而最终失去其原来的动词意义和在句子的核心谓词地位，虚化成表引进服务对象的介词，从而导致其双宾语结构的消失，形成新的“介·宾·动”结构。     

A family of estimators of population variance in two-occasion rotation patterns

Abstract

In this article, we have considered the problem of estimation of population variance on current (second) occasion in two occasion successive (rotation) sampling. A class of estimators of population variance has been proposed and its asymptotic properties have been discussed. The proposed class of estimators is compared with the sample variance estimator when there is no matching from the previous occasion and the Singh et al. (2013) estimator. Optimum replacement policy is discussed. It has been shown that the suggested estimator is more efficient than the Singh et al. (2013) estimator and a usual unbiased estimator when there is no matching. An empirical study is carried out in support of the present study.     

对《劳动合同法》立法宗旨的认识

《劳动合同法》从立法之初,其立法宗旨就引发了社会各界的激烈争论,主要集中在立法根据以及＂单保护＂还是＂双保护＂等问题上。应从倾斜保护的角度认识《劳动合同法》的立法宗旨,即《劳动合同法》既不是＂单保护＂,也不是＂双保护＂,而是在保护劳动者权益的同时,兼顾保护了用人单位的利益。     

Exact likelihood inference for Laplace distribution based on Type-II censored samples

We develop exact inference for the location and scale parameters of the Laplace (double exponential) distribution based on their maximum likelihood estimators from a Type-II censored sample. Based on some pivotal quantities, exact confidence intervals and tests of hypotheses are constructed. Upon conditioning first on the number of observations that are below the population median, exact distributions of the pivotal quantities are expressed as mixtures of linear combinations and of ratios of linear combinations of standard exponential random variables, which facilitates the computation of quantiles of these pivotal quantities. Tables of quantiles are presented for the complete sample case.     

Comments

In this paper we compare Bartlett-corrected, bootstrap, and fast double bootstrap tests on maximum likelihood estimates of cointegration parameters. The key result is that both the bootstrap and the Bartlett-corrected tests must be based on the unrestricted estimates of the cointegrating vectors: procedures based on the restricted estimates have almost no power. The small sample size bias of the asymptotic test appears so severe as to advise strongly against its use with the sample sizes commonly available; the fast double bootstrap test minimizes size bias, while the Bartlett-corrected test is somehow more powerful.     

如何发现DNA是生命的遗传物质

从核酸的发现到DNA双螺旋结构模型建立历时80余年,人类最终确认了DNA是生命的遗传物质,解决了一个生命科学研究中极其关键的重大问题。因此,对此段历史的研究具有重要意义。全面回顾此间发生的对揭示DNA的结构和功能具有重要影响的事件,包括米歇尔发现核酸、列文提出＂四核苷酸假说＂、格里菲斯等人的转化实验、査伽夫提出碱基配对规律,以及沃森和克里克建立DNA双螺旋结构模型,在此基础上阐述人类发现DNA是遗传物质的研究历程,进而探讨科学研究的规律。     

Electile Dysfunction

This essay combines Burke's burlesque frame and Jamieson's double binds to create a hybrid gendered theory for rhetorically analyzing the aggressive sexualization of 2008 United States vice presidential candidate Sarah Palin. The essay develops our theory titled the “burlesque binds” and explicates a specific form of a burlesque bind: the “MILF frame.” Palin's aggressively sexualized representation was united under the crass acronym MILF, which stands for “Mom I'd Like to Fuck.” The MILF frame emphasized Palin's feminine qualities, positioning her as a “trophy vice” with no political acumen, and highlighted her masculine behaviors, but deflated them through sexual objectification. The unification of the binds and burlesque theories reveals how Palin's role as a social actor was not simply circumscribed but shut down: she was deemed unfit by both masculine and feminine standards, by both public and private sphere conventions. Although Sarah Palin has arguably been the most prevalent subject of the political MILF frame, our essay catalogues other instances of female political leaders experiencing this type of symbolic degradation, suggesting the MILF frame's vast influence.