466期

最新文章

• Propriety of the posterior distribution and existence of the MLE for regression models with covariates missing at random AI翻译
  作者：Chen, MH; Ibrahim, JG; Shao, QM
  作者单位：University of Connecticut; University of North Carolina; University of North Carolina Chapel Hill; University of Oregon; National University of Singapore
  摘要：Characterizing model identifiability in the presence of missing covariate data is a very important issue in missing data problems. In this article. we characterize the propriety of the posterior distribution of the regression coefficients for some general classes of regression models, including the class of generalized linear models (GLM's) and parametric survival models with right-censored data. Toward this goal, we 14 derive some very general and easy-to-check conditions for the matrix of co...
• Heteroscedastic one-way ANOVA and lack-of-fit tests AI翻译
  作者：Akritas, MG; Papadatos, N
  作者单位：Pennsylvania Commonwealth System of Higher Education (PCSHE); Pennsylvania State University; Pennsylvania State University - University Park; National & Kapodistrian University of Athens
  摘要：Recent articles have considered the asymptotic behavior of the one-way analysis of variance (ANOVA) F statistic when the number of levels or groups is large. In these articles, the results were obtained under the assumption of homoscedasticity and for the case when the sample or group sizes n(i) remain fixed as the number of groups, a, tends to infinity. In this article. we study both weighted and unweighted test statistics in the heteroscedastic case. The unweighted statistic is new and can b...
• Cholesky residuals for assessing normal errors in a linear model with correlated outcomes AI翻译
  作者：Houseman, EA; Ryan, LM; Coull, BA
  作者单位：Harvard University; Harvard T.H. Chan School of Public Health
  摘要：Despite the widespread popularity of linear models for correlated outcomes (e.g., linear mixed models and time series models), distribution diagnostic methodology remains relatively underdeveloped in this context. In this article we present an easy-to-implement approach that lends itself to graphical displays of model fit. Our approach involves multiplying the estimated marginal residual vector by the Cholesky decomposition of the inverse of the estimated marginal variance matrix. The resultin...
• Sieve maximum likelihood estimator for semiparametric regression models with current status data AI翻译
  作者：Xue, HQ; Lam, KF; Li, GY
  作者单位：Chinese Academy of Sciences; University of Chinese Academy of Sciences, CAS; University of Hong Kong; Chinese Academy of Sciences; Academy of Mathematics & System Sciences, CAS
  摘要：In a randomized controlled clinical trial study where the response variable of interest is the time to occurrence of a certain event, it is often too expensive or even impossible to observe the exact time. However, the current status of the subject at a random time of inspection is much more natural, feasible, and practical in terms of cost-effectiveness. This article considers a semiparametric regression model that consists of parametric and nonparametric regression components. A sieve maximu...
• A classical study of catch-effort models for Hectory's dolphins AI翻译
  作者：King, R; Brooks, SP
  作者单位：University of St Andrews; University of Cambridge
  摘要：Effective management is the key to the protection of many endangered species. Identification of the primary factors that affect their survival often lead to L introduction of strategies to improve survival rates. In this article, we consider a small population of Hector's dolphins located off the coast of New Zealand and the impact that the establishment of a seasonal sanctuary has on their survival and migration rates. Using Akaike's information criterion and an extension of the simulated ann...
• Estimation in partially linear models with missing covariates AI翻译
  作者：Liang, H; Wang, SJ; Robins, JM; Carroll, RJ
  作者单位：Texas A&M University System; Texas A&M University College Station; Harvard University; Harvard T.H. Chan School of Public Health
  摘要：The partially linear model Y = X(T)beta + v(Z) + epsilon has been studied extensively when data are completely observed. In this article, we consider the case where the covariate X is sometimes missing, with missingness probability pi depending on (Y, Z). New methods are developed for estimating and v(.). Our methods are shown to outperform asymptotically methods based only on the complete data. Asymptotic efficiency is discussed. and the semiparametric efficient score function is derived. Jus...
• Multiple comparison of several linear regression models AI翻译
  作者：Liu, W; Jamshidian, M; Zhang, Y
  作者单位：University of Southampton; University of Southampton; California State University System; California State University Fullerton; State University System of Florida; University of Central Florida
  摘要：Research on multiple comparison during the past 50 years or so has focused mainly on the comparison of several population means. Several years ago. Spurrier considered the multiple comparison of several simple linear regression lines. He constructed simultaneous confidence bands for all of the contrasts of the simple linear regression lines over the entire range (-infinity, infinity) when the models have the same design matrices. This article extends Spurrier's work in several directions. Firs...
• To model or not to model? competing modes of inference for finite population sampling AI翻译
  作者：Little, RJ
  作者单位：University of Michigan System; University of Michigan
  摘要：Finite population sampling is perhaps the only area of statistics in which the primary mode of analysis is based on the randomization distribution, rather than on statistical models for the measured variables. This article reviews the debate between design-based and model-based inference. The basic features of the two approaches are illustrated using the case of inference about the mean from stratified random samples. Strengths and weakness of design-based and model-based inference for surveys...
• Variable selection in data mining: Building a predictive model for bankruptcy AI翻译
  作者：Foster, DP; Stine, RA
  作者单位：University of Pennsylvania
  摘要：We predict the onset of personal bankruptcy using least squares regression. Although well publicized, only 2,244 bankruptcies occur in our dataset of 2.9 million months of credit-card activity. We use stepwise selection to find predictors of these from a mix of payment history. debt load. demographics, and their interactions. This combination of rare responses and over 67,000 possible predictors leads to a challenging modeling question: How does one separate coincidental from useful predictors...
• Parameterization and Bayesian modeling AI翻译
  作者：Gelman, A
  作者单位：Columbia University
  摘要：Progress in statistical computation often leads to advances in statistical modeling. For example, it is surprisingly common that an existing model is reparameterized. solely, for computational purposes, but then this new configuration motivates a new family of models that is useful in applied statistics. One reason why this phenomenon may not have been noticed in statistics is that reparameterizations do not change the likelihood. In a Bayesian framework, however, a transformation of parameter...