On fiducial generators

Fiducial inference has been gaining presence recently and it is the intention of the present article to look at the notion of fiducial generators; meaning procedures to simulate parameter values that in some sense correspond to simulations from some implicit fiducial distribution. It is well known that when the distribution has group structure, stemming from the natural pivotal associated, a fiducial may be obtained. It is in the non group distributions that there appears to be still room for finding a fiducial distribution. Recently some general procedures have been proposed for dealing with generalized fiducials, but these depend on certain choices for a structural equation or a fiducial equation, as in Hannig (2009 Hannig, J. (2009). On generalized fiducial inference. Stat. Sin. 19:491–544.[Web of Science ®] , [Google Scholar]) or Taraldsen and Lindqvist (2013 Taraldsen, G., Lindqvist, B.H. (2013). Fiducial theory and optimal inference. Ann. Stat. 41(1):323–341.[Crossref], [Web of Science ®] , [Google Scholar]), respectively. A brief presentation is made of an earlier approach to fiducial inference for multivariate parameters, as in Brillinger (1962 Brillinger, D.R. (1962). Examples bearing on the definition of fiducial probability with a bibliography. Ann. Math. Stat. 33(4):1349–1355.[Crossref] , [Google Scholar]), and the implied fiducial generator introduced in Engen and Lillegård (1997 Engen, S., Lillegård, M. (1997). Stochastic simulation conditioned on sufficient statistics. Biometrika 84(1):235–240.[Crossref], [Web of Science ®] , [Google Scholar]), trying to connect them. Three interesting non group distributions are seen; two of them, the truncated exponential and the two-parameter gamma, already reported in literature. A third non group distribution is analyzed; the inverse Gaussian, connecting the fiducial that results following Brillinger (1962 Brillinger, D.R. (1962). Examples bearing on the definition of fiducial probability with a bibliography. Ann. Math. Stat. 33(4):1349–1355.[Crossref] , [Google Scholar]), with a result pertaining confidence limits for the shape parameter in Hsieh (1990 Hsieh, H.K. (1990). Inferences on the coefficient of variation of an inverse-Gaussian distribution. Commun. Stat. - Theory Methods 19(5):1589–1605.[Taylor &; Francis Online], [Web of Science ®] , [Google Scholar]). In the three cases, comparisons are made with the Bayesian posteriors that have been known to be close numerically. Some discussion is made on the issue of singularities of the fiducial density and its connection with densities that do not integrate to unity. As to the case of discrete observables, some comments are made for the Bernoulli distribution, only.     

Bayesian expectile regression with asymmetric normal distribution

In this paper, we adopt the Bayesian approach to expectile regression employing a likelihood function that is based on an asymmetric normal distribution. We demonstrate that improper uniform priors for the unknown model parameters yield a proper joint posterior. Three simulated data sets were generated to evaluate the proposed method which show that Bayesian expectile regression performs well and has different characteristics comparing with Bayesian quantile regression. We also apply this approach into two real data analysis.     

Mighty Crime Victims: Victims' Rights and Neoliberalism in the American Conjuncture

Over the last 30 years, the victims' rights movement has expanded the role of victims in the American criminal justice system. As a result of this movement, judges, prosecutors and parole boards must now hear victims' views at all stages of the criminal justice process, including plea bargains, and sentencing and parole decisions. Legislative efforts have been spearheaded by victims' families, and legislation has been named after deceased victims. Also, victims' families can now view executions in states across the country. The victims' right movement assumes that the criminal justice system should privilege victims' interests over those of society. In so doing, it denies society as a consideration, which is tantamount to a denial of society itself. This article positions victims' rights' denial of society within the current conjuncture, marked as it is by the contradiction between neoliberalism and American liberalism. Victims' rights' denial of society is an expression of the denial of society implicit in American neoliberalism, which seeks to privilege individual interests over those of society. This paper argues that victims' rights is a powerful element of the neoliberal project for three reasons. First, victims' rights imputes the authority of legal discourse to neoliberalism's denial of society. Second, important actors in the rise of neoliberalism have also worked to establish victims' rights. Finally, victims' rights comprehensively circulates throughout America and offers powerful points of identification that incorporate Americans into the victims' rights formation. I explore the denial of society in three victims' rights practices: naming criminal legislation after crime victims and passing such laws in honour of victims; allowing victims' families to view executions; and prosecutors, judges and police personnel making legal decisions according to victims' wishes. I examine the consonant denial of society in three neoliberal practices – monetarism, supply-side economics and welfare reform – and demonstrate how neoliberal advocates like Bill Clinton, Ronald Reagan and Paul Gann worked to advance victims' rights. I also describe the production, consumption and comprehensive circulation of victims' rights texts. Finally, I consider Cultural Studies' unique contribution to legal studies.     

Goodness-of-fit test for exponentiality based on spacings for general progressive Type-II censored data

There have been numerous tests proposed to determine whether or not the exponential model is suitable for a given data set. In this article, we propose a new test statistic based on spacings to test whether the general progressive Type-II censored samples are from exponential distribution. The null distribution of the test statistic is discussed and it could be approximated by the standard normal distribution. Meanwhile, we propose an approximate method for calculating the expectation and variance of samples under null hypothesis and corresponding power function is also given. Then, a simulation study is conducted. We calculate the approximation of the power based on normality and compare the results with those obtained by Monte Carlo simulation under different alternatives with distinct types of hazard function. Results of simulation study disclose that the power properties of this statistic by using Monte Carlo simulation are better for the alternatives with monotone increasing hazard function, and otherwise, normal approximation simulation results are relatively better. Finally, two illustrative examples are presented.     

Estimation of parameters of inverse Weibull distribution and application to multi-component stress-strength model

The problem of estimation of the parameters of two-parameter inverse Weibull distributions has been considered. We establish existence and uniqueness of the maximum likelihood estimators of the scale and shape parameters. We derive Bayes estimators of the parameters under the entropy loss function. Hierarchical Bayes estimator, equivariant estimator and a class of minimax estimators are derived when shape parameter is known. Ordered Bayes estimators using information about second population are also derived. We investigate the reliability of multi-component stress-strength model using classical and Bayesian approaches. Risk comparison of the classical and Bayes estimators is done using Monte Carlo simulations. Applications of the proposed estimators are shown using real data sets.     

Quantitative Risk Assessment of Listeria monocytogenes in French Cold-Smoked Salmon: II. Risk Characterization

A model for the assessment of exposure to Listeria monocytogenes from cold-smoked salmon consumption in France was presented in the first of this pair of articles (Pouillot et al ., 2007, Risk Analysis, 27:683–700). In the present study, the exposure model output was combined with an internationally accepted hazard characterization model, adapted to the French situation, to assess the risk of invasive listeriosis from cold-smoked salmon consumption in France in a second-order Monte Carlo simulation framework. The annual number of cases of invasive listeriosis due to cold-smoked salmon consumption in France is estimated to be 307, with a very large credible interval ([10; 12,453]), reflecting data uncertainty. This uncertainty is mainly associated with the dose-response model. Despite the significant uncertainty associated with the predictions, this model provides a scientific base for risk managers and food business operators to manage the risk linked to cold-smoked salmon contaminated with L. monocytogenes. Under the modeling assumptions, risk would be efficiently reduced through a decrease in the prevalence of L. monocytogenes or better control of the last steps of the cold chain (shorter and/or colder storage during the consumer step), whereas reduction of the initial contamination levels of the contaminated products and improvement in the first steps of the cold chain do not seem to be promising strategies. An attempt to apply the recent risk-based concept of FSO (food safety objective) on this example underlines the ambiguity in practical implementation of the risk management metrics and the need for further elaboration on these concepts.     

论作为文学文化学的“西安学”

＂西安学＂从理论上说是一个学科集群。但中外城市学研究经验及成果表明,城市学主要是一种文学文化学,目标在于构建城市精神镜像。作为文学文化学的西安学应以城市的精神体验为主要方式构建城市镜像知识。其方法有直观体验城市和通过文学体验城市两种。本雅明对19世纪巴黎的研究及李欧梵对20世纪三四十年代上海的研究为文学体验提供了范例,西安学应以此为借鉴拓展其研究视界。     

清代喀喇沁地区的蒙地开垦之影响新论

清代以来喀喇沁地区的移民和开垦,不仅造成了当地蒙古族传统游牧经济转型为半农半牧经济,甚至是纯农业经济,蒙地的开垦对喀喇沁地区蒙古族的传统生活方式也产生了深远的影响,同时也奠定了现在喀喇沁地区蒙古族农业人口分布的基本格局。