NACA Restricted Bulletins

Report presents tables and charts for the evaluation of profile drag from wake surveys at high supersonic speeds. Two methods of evaluation are presented: an exact method that can be used on a wake of any shape and a simple approximate method that can be used when the variation of total-pressure loss across the wave has a typical form

Resampling-based empirical prediction: an application to small area estimation

Best linear unbiased prediction is well known for its wide range of applications including small area estimation. While the theory is well established for mixed linear models and under normality of the error and mixing distributions, the literature is sparse for nonlinear mixed models under nonnormality of the error distribution or of the mixing distributions. We develop a resampling-based unified approach for predicting mixed effects under a generalized mixed model set-up. Second-order-accurate nonnegative estimators of mean squared prediction errors are also developed. Given the parametric model, the proposed methodology automatically produces estimators of the small area parameters and their mean squared prediction errors, without requiring explicit analytical expressions for the mean squared prediction errors. Copyright 2007, Oxford University Press.

A TIME VARYING MULTIVARIATE AUTOREGRESSIVE MODELING OF ECONOMETRIC TIME SERIES

This series contains research reports, written by or in cooperation with staff members of the Statistical Research Division, whose content may be of interest to the general statistical research community. The views re-flected in these reports are not necessarily those of the Census Bureau nor do they necessarily represent Census Bureau statistical policy or prac-tice. Inquiries may be addressed to the author(s) or the SRD Report Serie

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This series contains research reports, written by or in cooperation with staff members of the Statistical Research Division, whose content may be of interest to the general statistical research community. The views re-flected in these reports are not necessarily those ofathe Census Bureau nor do they necessarily represent Census Bureau statistical policy or prac-tice. Inquiries may be addressed to the author(s) or the SRD Report Serie

Hospital Characteristics and Mortality Rates.

The Health Care Financing Administration (HCFA) publishes hospital mortality rates each year. We undertook a study to identify characteristics of hospitals associated with variations in these rates. To do so, we obtained data on 3100 hospitals from the 1986 HCFA mortality study and the American Hospital Association\u27s 1986 annual survey of hospitals. The mortality rates were adjusted for each hospital\u27s case mix and other characteristics of its patients. The mortality rate for all hospitalizations was 116 per 1000 patients. Adjusted mortality rates were significantly higher for for-profit hospitals (121 per 1000) and public hospitals (120 per 1000) than for private not-for-profit hospitals (114 per 1000; P less than 0.0001 for both comparisons). Osteopathic hospitals also had an adjusted mortality rate that was significantly higher than average (129 per 1000; P less than 0.0001). Private teaching hospitals had a significantly lower adjusted mortality rate (108 per 1000) than private nonteaching hospitals (116 per 1000; P less than 0.0001). Adjusted mortality rates were also compared for hospitals in the upper and lower fourths of the sample in terms of certain hospital characteristics. The mortality rates were 112 and 121 per 1000 for the hospitals in the upper and lower fourths, respectively, in terms of the percentage of physicians who were board-certified specialists (P less than 0.0001), 112 and 120 per 1000 for occupancy rate (P less than 0.0001), 113 and 120 per 1000 for payroll expenses per hospital bed (P less than 0.0001), and 113 and 119 per 1000 for the percentage of nurses who were registered (P less than 0.0001)