Bayes estimation of Moran–Downton bivariate exponential distribution based on censored samples

In this paper, we discuss a Bayesian estimation procedure for the parameters in a Moran–Downton bivariate exponential distribution based on complete and censored samples. A Markov-chain Monte Carlo method is used to obtain the Bayes estimates of the parameters. An intensive simulation experiment is conducted to study the performance of the proposed Bayesian estimation procedure. Discussions and suggestions are provided based on the simulation results. A numerical example is presented to illustrate the Bayesian estimation procedure developed here and some concluding remarks are provided.     

Lower Confidence Limits on the Generalized Exponential Distribution Percentiles Under Progressive Type-I Interval Censoring

In industrial life test and survival analysis, the percentile estimation is always a practical issue with lower confidence bound required for maintenance purpose. Sampling distributions for the maximum likelihood estimators of percentiles are usually unknown. Bootstrap procedures are common ways to estimate the unknown sampling distributions. Five parametric bootstrap procedures are proposed to estimate the confidence lower bounds on maximum likelihood estimators for the generalized exponential (GE) distribution percentiles under progressive type-I interval censoring. An intensive simulation is conducted to evaluate the performances of proposed procedures. Finally, an example of 112 patients with plasma cell myeloma is given for illustration.     

Estimation of δ=P(X<Y) for Burr XII distribution based on the progressively first failure-censored samples

Let X and Y have two-parameter Burr XII distributions. The maximum-likelihood estimator of δ=P(X<Y) is studied under the progressively first failure-censored samples. Three confidence intervals of δ are constructed by using an asymptotic distribution of the maximum-likelihood estimator of δ and two bootstrapping procedures, respectively. Some computational results from intensive simulations are presented. An illustrative example is provided to demonstrate the application of the proposed method.     

A dynamic system for Gompertz model

Two-parameter Gompertz distribution has been introduced as a lifetime model for reliability inference recently. In this paper, the Gompertz distribution is proposed for the baseline lifetimes of components in a composite system. In this composite system, failure of a component induces increased load on the surviving components and thus increases component hazard rate via a power-trend process. Point estimates of the composite system parameters are obtained by the method of maximum likelihood. Interval estimates of the baseline survival function are obtained by using the maximum-likelihood estimator via a bootstrap percentile method. Two parametric bootstrap procedures are proposed to test whether the hazard rate function changes with the number of failed components. Intensive simulations are carried out to evaluate the performance of the proposed estimation procedure.     

Constructing Threat and Appropriating “Civil Rights”: Rhetorical Strategies of Gun Rights and English Only Leaders

Using a grounded theory method, we analyze the framing strategies of organizational leaders of the gun rights and English Only movements. Although we find greater variability in the framing strategies of English Only leaders, leaders of both movements mobilize fear by rhetorically constructing moral threats to American society in ways that draw on, and uphold, the ideals and practices of dominant social groups. In doing so, they appeal to their constituents' status anxieties. We also find that these movements engage in a particular form of frame transformation that we call “frame appropriation” to counter opponents' claims and broaden their support. Future research should examine when and how, and to what effect, other social movements similarly mobilize fear and engage in frame appropriation.     

Acceptance Sampling Plans from Truncated Life Tests Based on the Birnbaum–Saunders Distribution for Percentiles

Time to failure due to fatigue is one of the common quality characteristics in material engineering applications. In this article, acceptance sampling plans are developed for the Birnbaum–Saunders distribution percentiles when the life test is truncated at a pre-specified time. The minimum sample size necessary to ensure the specified life percentile is obtained under a given customer's risk. The operating characteristic values (and curves) of the sampling plans as well as the producer's risk are presented. The R package named spbsq is developed to implement the developed sampling plans. Two examples with real data sets are also given as illustration.     

A modified kernel quantile estimator under censoring

Based on right-censored data from a lifetime distribution F₀, a modification of the kernel quantile estimator is proposed. The advantage of this estimator is that the data play a role in the degree of smoothing of the estimator while retaining the desirable features of the kernel estimator. Convergence in probability and almost sure convergence of the estimator are discussed. Also, asymptotic normality and confidence bands are presented and some examples are given.     

On the mean squared error of nonparametric quantile estimators under random right-censorship

For randomly right-censored data, new asymptotic expressions for the mean squared errors of the product-limit quantile estimator and a kernel-type quantile estimator are presented in this paper. From these results a comparison of the two quantile estimators with respect to their mean squared errors is given.     

Private Polls and Presidential Policymaking: Reagan as a Facilitator of Change

Did the Reagan administration disregard majority will when craftingits policy initiatives? Did it cater to a narrow partisan constituencyinstead? The answers to these questions will help with an assessmentof Jacobs and Shapiro’s (2000b) hypothesis that presidentssince the late 1970s have used private White House survey researchas a tool to manipulate or assuage centrist public opinion whilemeeting the policy demands of their partisan core supporters,resulting in a decline in presidential responsiveness to majoritywill. Using the actual surveys administered by Richard Wirthlin(Reagan’s pollster) between 1981 and 1983, this articlewill demonstrate the level of consistency between majority opinionon 129 policy issues and Reagan’s behavior through 1984,and it will explore the conditions under which the presidentwas more or less likely to respond to public preferences. Thedata reveal that the Reagan administration was constrained bythe popular will in predicable ways: if the policy issues wereabout domestic concerns, highly popular, and visible in themedia, then the administration acted in line with public preferencesmore than 70 percent of the time. Further, Reagan and his adviserswere selective in responding to party activists: they championedissues drawn from their conservative ideological agenda thatfit with the current tide in public opinion, while sidesteppingother issues dear to party activists that encountered strongmajority resistance. While I do not contest Jacobs and Shapiro’s(2000b) important observation that presidents often use surveyresearch to "craft talk" in an attempt to channel the publicdebate, the evidence here highlights how the president nonethelessremains constrained by the popular will, at least on domesticissues.