Manipulating Statistical Hypotheses and Tests as Boolean Functions

Statistical hypotheses and test statistics are Boolean functions that can be manipulated using the tools of Boolean algebra. These tools are particularly useful for exploring multiple comparisons or simultaneous inference theory, in which multiparameter hypotheses or multiparameter test statistics may be decomposed into combinations of uniparameter hypotheses or uniparameter tests. These concepts are illustrated with both finite and infinite decompositions of familiar multiparameter hypotheses and tests. The corresponding decompositions of acceptance regions and rejection regions are also shown. Finally, the close relationship between hypothesis and test decompositions and Roy's union—intersection principle is demonstrated by a derivation of the union—intersection test of the univariate general linear hypothesis.     

Nonparametric comparison of curves with dependent errors

Suppose that data {(x _l,i,n , y _l,i,n ): l?=?1, …, k; i?=?1, …, n} are observed from the regression models: Y _l,i,n ?=?m _l (x _l,i,n )?+?? _l,i,n , l?=?1, …, k, where the regression functions {m _l } _l=1 ^k are unknown and the random errors {? _l,i,n } are dependent, following an MA(∞) structure. A new test is proposed for testing the hypothesis H ₀: m ₁?=?·?·?·?=?m _k , without assuming that {m _l } _l=1 ^k are in a parametric family. The criterion of the test derives from a Crámer-von-Mises-type functional based on different distances between {[mcirc]} _l and {[mcirc]} _s , l?≠?s, l, s?=?1, …, k, where {[mcirc] _l } _l=1 ^k are nonparametric Gasser–Müller estimators of {m _l } _l=1 ^k . A generalization of the test to the case of unequal design points, with different sample sizes {n _l } _l=1 ^k and different design densities {f _l } _l=1 ^k , is also considered. The asymptotic normality of the test statistic is obtained under general conditions. Finally, a simulation study and an analysis with real data show a good behavior of the proposed test.     

Sample Size Calculation for the Therapeutic Equivalence Problem

A method is proposed for the sample size calculation in the case of therapeutic equivalence of two pharmaceuticals, when the decision is based on post-treatment differences and the post-treatment values are dependent on the pretreatment ones. When the correlation coefficient is large (over 0.7), it is shown that sample size calculation (and the corresponding hypothesis test) based on the sample statistic formed by the mean difference of the post–pre differences of each group has smaller variance and hence leads to smaller sample sizes.     

A Revisit to the Behrens–Fisher Problem: Comparison of Five Test Methods

We revisit the well-known Behrens–Fisher problem and apply a newly developed ‘Computational Approach Test’ (CAT) to test the equality of two population means where the populations are assumed to be normal with unknown and possibly unequal variances. An advantage of the CAT is that it does not require the explicit knowledge of the sampling distribution of the test statistic. The CAT is then compared with three widely accepted tests—Welch–Satterthwaite test (WST), Cochran–Cox test (CCT), ‘Generalized p-value’ test (GPT)—and a recently suggested test based on the jackknife procedure, called Singh–Saxena–Srivastava test (SSST). Further, model robustness of these five tests are studied when the data actually came from t-distributions, but wrongly perceived as normal ones. Our detailed study based on a comprehensive simulation indicate some interesting results including the facts that the GPT is quite conservative, and the SSST is not as good as it has been claimed in the literature. To the best of our knowledge, the trends observed in our study have not been reported earlier in the existing literature.     

Testing the Equality of the Noncentrality Parameters of Two Noncentral t-Distributions with Identical Degrees of Freedom

The problem of testing the equality of the noncentrality parameters of two noncentral t-distributions with identical degrees of freedom is considered, which arises from the comparison of two signal-to-noise ratios for simple linear regression models. A test procedure is derived that is guaranteed to maintain Type I error while having only minimal amounts of conservativeness, and comparisons are made with several other approaches to this problem based on variance stabilizing transformations. The new procedure derived in this article is shown to have good properties and will be useful for practitioners.     

Do greater amounts of FDI cause higher pollution levels? Evidence from OECD countries

Using an ARDL model for a panel of 15 OECD countries, this work analyses the impact that FDI, both jointly and by sector, has on CO₂ emissions. The findings reveal that these countries are yielding to the pressure on the trade sector. Unexpectedly, gross fixed capital formation shrink pollution, excluding in the mining sector. With findings supporting the Pollution Haven Hypothesis, policymakers must pay attention to FDI inflows, ensuring that FDI place high importance on the transfer of green technologies to improve the efficiency. These goals could be achieved through an increase in the stringency of environmental laws within the host countries, especially the ones related to FDI.     

Does performance management affect nurses’ well-being?

AimThis article focuses on employee performance-management practices in the healthcare sector. We specifically aim to contribute to a better understanding of the impact of employee performance-management practices on affective well-being of nurses in hospitals. Theory suggests that the features of employee-performance management (planning and evaluation of individual performances) predict affective well-being (in this study: job satisfaction and affective commitment).MethodsPerformance-management planning and evaluation and affective well-being were drawn from a survey of nurses at a Flemish hospital. Separate estimations were performed for different aspects of affective well-being.ResultsPerformance planning has a negative effect on job satisfaction of nurses. Both vertical alignment and satisfaction with the employee performance-management system increase the affective well-being of nurses; however, the impact of vertical alignment differs for different aspects of affective well-being (i.e. job satisfaction and affective commitment).ConclusionPerformance-management planning and evaluation of nurses are associated with attitudinal outcomes. The results indicate that employee performance-management features have different impacts on different aspects of well-being.     

Modeling of Discrete HNBUE Class with Hypothesis Testing Application

A new model is proposed to test whether an equipment whose life is measured in discrete time units fails due to uncontrollable chance factors alone against the alternatives that it degrades over time in the sense of discrete HNBUE (harmonic new better than used in expectation) aging. The test is shown to be consistent and the asymptotic distribution of the test statistic has been obtained. The critical points and the power of the test against various alternatives from discrete HNBUE class have been studied by means of simulation. Finally, the test is applied to a discrete reliability data to examine the performance.     

Babes in tech land: expo labor as capitalist technology’s erotic body

This article investigates the tech industry practice of hiring “booth babes”—female models costumed in erotic outfits—to introduce new technologies at expos. My research identifies a gendered industrial logic that simultaneously sexualizes promotional spectacles while undervaluing women who create them. Challenging industrial ideologies that view booth babe labor as outside of the tech industry, I engage first in a discourse analysis of job calls for tradeshow modeling gigs, gray literature that evidences not only their industrial presence but also the values that tech companies place on their work. I then turn to their labor conditions, as conveyed through ethnographic interviews with tradeshow models, before drawing connections between booth babe work and other forms of post-Fordist labor. Finally, I propose that the utility of booth babes to the tech industry stems from their enactment of “promosexuality,” a set of corporate erotics oriented toward capitalist promotion.     

我院96级专科学生英语学习成绩研究与分析

为了更详细地了解学生的英语学习情况,以增强和促进我院的专科英语教学,本文对我院96级学生的英语学习成绩用统计中的回归分析和假设检验进行了统计和分析,并提出了三点建议。