论文检索

基于动物线粒体基因组排列的贝叶斯系统发育推断AI 解读

Summary The determination of evolutionary relationships is a fundamental problem in evolutionary biology. Genome arrangement data are potentially more informative than deoxyribonucleic acid sequence data for inferring evolutionary relationships between distantly related taxa. We describe a Bayesian framework for phylogenetic inference from mitochondrial genome arrangement data using Markov chain Monte Carlo methods. We apply the method to assess evolutionary relationships…

死刑陪审员的公正性：不同层级与缺失机制下的贝叶斯模型比较AI 解读

Jurors who are opposed to the death penalty are excluded from serving on trials in which the defendant may be sentenced to death. The exclusion of such jurors from death-penalty trials raises some concern about the fairness of these juries in deciding the guilt or innocence of a defendant. This article uses data from a survey of behaviors and beliefs of jurors conducted at the conclusion of non–capital offense trials to study this issue. A Bayesian hierarchical model is…

死刑陪审员的公正性：不同层级与缺失机制的贝叶斯模型比较AI 解读

Jurors who are opposed to the death penalty are excluded from serving on trials in which the defendant may be sentenced to death. The exclusion of such jurors from death-penalty trials raises some concern about the fairness of these juries in deciding the guilt or innocence of a defendant. This article uses data from a survey of behaviors and beliefs of jurors conducted at the conclusion of non–capital offense trials to study this issue. A Bayesian hierarchical model is…

临床试验设计中的贝叶斯方法与伦理AI 解读

Partial table of contents: MAJOR ISSUES Ethically Optimizing Clinical Trials (K. Schaffner) Admissibility of Treatment (N. Sedransk) TEST CASE: VERAPAMIL/NITROPRUSSIDE The Mechanics of Conducting a Clinical Trial (E. Heitmiller & T. Blanck) Issues of Statistical Design (N. Sedransk) Operational History and Procedural Feasibility (J. Kadane) Verapamil versus Nitroprusside: Results of the Clinical Trial I (J. Kadane & N. Sedransk) Verapamil versus Nitroprusside: Results of the…

摘要暂缺

偏序偏好的表示AI 解读

This essay considers decision-theoretic foundations for robust Bayesian statistics. We modify the approach of Ramsey, de Finetti, Savage and Anscombe and Aumann in giving axioms for a theory of robust preferences. We establish that preferences which satisfy axioms for robust preferences can be represented by a set of expected utilities. In the presence of two axioms relating to state-independent utility, robust preferences are represented by a set of probability/utility…

面向他人分析的最优实验设计AI 解读

We consider the optimal design of experiments in which estimation and design are performed by different parties. The parties are assumed to share similar goals, as reflected by a common loss function, but they may have different prior beliefs. After presenting a few motivating examples, we examine the problem of optimal sample size selection under a normal likelihood with constant cost per observation. We also consider the problem of optimal allocation for given overall…

对称上概率AI 解读

As a first step toward developing statistical models based on upper and lower probabilities, we study upper probabilities and upper expectations on the unit interval that are symmetric, by which we mean invariant with respect to equimeasurability. These upper probabilities are generalizations of uniform probability measures. We give some characterizations of these upper probabilities. Specifically, we show that symmetry of the upper expectation functional is equivalent to…

期望界限的计算AI 解读

One method for evaluating the sensitivity of a Bayesian analysis is to embed the prior into a class of priors. Then bounds on prior and posterior quantities of interest must be computed. This approach to inference, often called robust Bayesian inference, has received much attention lately. Implementing robust Bayesian methods entails difficult computations, especially if the parameter space is high dimensional. In this article we develop a Monte Carlo approach to computing…

状态依赖效用AI 解读

Several axiom systems for preference among acts lead to a unique probability and a state-independent utility such that acts are ranked according to their expected utilities. These axioms have been used as a foundation for Bayesian decision theory and subjective probability calculus. In this article we note that the uniqueness of the probability is relative to the choice of what counts as a constant outcome. Although it is sometimes clear what should be considered constant,…

调整美国1980年人口与住房普查结果AI 解读

In 1980, several cities and states sued the U.S. Census Bureau to correct census results. This correction would adjust for the differential undercounting of Blacks and Hispanics, especially in cities. In this article, the authors, each of whom testified for New York City and State in their joint lawsuit against the Census Bureau, describe the likely pattern of the undercount and present a method to adjust for it. We first explain why the undercount is concentrated among…

调整1980年美国人口与住房普查AI 解读

In 1980, several cities and states sued the U.S. Census Bureau to correct census results. This correction would adjust for the differential undercounting of Blacks and Hispanics, especially in cities. In this article, the authors, each of whom testified for New York City and State in their joint lawsuit against the Census Bureau, describe the likely pattern of the undercount and present a method to adjust for it. We first explain why the undercount is concentrated among…

非正函数期望与方差的完全指数型拉普拉斯近似AI 解读

Tierney and Kadane (1986) presented a simple second-order approximation for posterior expectations of positive functions. They used Laplace's method for asymptotic evaluation of integrals, in which the integrand is written as f(θ)exp(-nh(θ)) and the function h is approximated by a quadratic. The form in which they applied Laplace's method, however, was fully exponential: The integrand was written instead as exp[− nh(θ) + log f(θ)]; this allowed first-order approximations to…

贝叶斯分析中影响与敏感性评估的近似方法AI 解读

We use asymptotic approximations to posterior expectations in deriving diagnostics for case influence and prior sensitivity. We obtain an easily-interpreted expression for the change in posterior expectation following perturbation of the problem, which also produces a useful interpretation of the likelihood displacement discussed by Cook & Weisberg (1982). In addition, we propose two simple diagnostics of posterior nonnor mality. The leukaemia data analysed by Feigl & Zelen…

非线性函数的边际密度近似AI 解读

This paper presents an asymptotic approximation for the marginal density of a nonlinear function g(θ) that is applicable when the joint density of θ is dominated by a single mode and the Jacobian of g is of full rank near that mode. The approximation is based on Laplace's method and its asymptotic properties are similar to those of the saddlepoint approximation. The approximation is applied to the computation of a marginal posterior density, a marginal sampling density and a…

摘要暂缺

后验矩与边际密度的精确近似方法AI 解读

This article describes approximations to the posterior means and variances of positive functions of a real or vector-valued parameter, and to the marginal posterior densities of arbitrary (i.e., not necessarily positive) parameters. These approximations can also be used to compute approximate predictive densities. To apply the proposed method, one only needs to be able to maximize slightly modified likelihood functions and to evaluate the observed information at the maxima.…

摘要暂缺

死刑案件陪审团：一项法律程序的统计分析AI 解读

Potential jurors in capital cases are often queried on their attitudes toward capital punishment. The extreme groups say they would never or they would always approve capital punishment, given a guilty verdict. In many jurisdictions, these two groups are routinely excluded from juries deciding whether the defendant is guilty in capital cases. This exclusion persists even when the potential jurors say they could be fair and impartial in deciding guilt or innocence. The…

审理死刑案件的陪审团：一项法律程序的统计分析AI 解读

Potential jurors in capital cases are often queried on their attitudes toward capital punishment. The extreme groups say they would never or they would always approve capital punishment, given a guilty verdict. In many jurisdictions, these two groups are routinely excluded from juries deciding whether the defendant is guilty in capital cases. This exclusion persists even when the potential jurors say they could be fair and impartial in deciding guilt or innocence. The…

油气钻井成本：约束稳健回归的应用AI 解读

The robust regression method of Huber (1973) is used to fit a model to the cost of drilling for petroleum. Because the model includes a categorical variable (well type), a linear constraint is imposed on the parameter estimates Because the model was fit to the logarithm of cost and because it will be used to make repeated predictions of cost, an adjustment that approximately unbiases the predictions is imposed. The numerical values of the estimates are discussed, and a…

石油与天然气钻井成本：约束稳健回归的应用AI 解读

The robust regression method of Huber (1973) is used to fit a model to the cost of drilling for petroleum. Because the model includes a categorical variable (well type), a linear constraint is imposed on the parameter estimates Because the model was fit to the logarithm of cost and because it will be used to make repeated predictions of cost, an adjustment that approximately unbiases the predictions is imposed. The numerical values of the estimates are discussed, and a…

稳定决策问题AI 解读

A decision problem is characterized by a loss function $V$ and opinion $H$. The pair $(V, H)$ is said to be strongly stable iff for every sequence $F_n \rightarrow_\omega H, G_n \rightarrow_\omega H$ and $L_n\rightarrow V, W_n\rightarrow V$ uniformly, $\lim_{\varepsilon \downarrow 0} \lim \sup_{n\rightarrow \infty} \lbrack \int L_n(\theta, D_n(\varepsilon)) dF_n(\theta) - \inf_D \int L_n(\theta, D) dF_n(\theta)\rbrack = 0$ for every sequence $D_n(\varepsilon)$ satisfying $\int W_n(\theta, D_n(\varepsilon)) dG_n(\theta) \leqq \inf_D \int W_n(\theta, D) dG_n(\theta) + \varepsilon.$…

摘要暂缺