Shrinkage Confidence Procedures

The possibility of improving on the usual multivariate normal confidence was first discussed in Stein (1962). Using the ideas of shrinkage, through Bayesian and empirical Bayesian arguments, domination results, both analytic and numerical, have been obtained. Here we trace some of the developments in confidence set estimation.Comment: Published in at http://dx.doi.org/10.1214/10-STS319 the Statistical Science (http://www.imstat.org/sts/) by the Institute of Mathematical Statistics (http://www.imstat.org

Minimax estimation with thresholding and its application to wavelet analysis

Many statistical practices involve choosing between a full model and reduced models where some coefficients are reduced to zero. Data were used to select a model with estimated coefficients. Is it possible to do so and still come up with an estimator always better than the traditional estimator based on the full model? The James-Stein estimator is such an estimator, having a property called minimaxity. However, the estimator considers only one reduced model, namely the origin. Hence it reduces no coefficient estimator to zero or every coefficient estimator to zero. In many applications including wavelet analysis, what should be more desirable is to reduce to zero only the estimators smaller than a threshold, called thresholding in this paper. Is it possible to construct this kind of estimators which are minimax? In this paper, we construct such minimax estimators which perform thresholding. We apply our recommended estimator to the wavelet analysis and show that it performs the best among the well-known estimators aiming simultaneously at estimation and model selection. Some of our estimators are also shown to be asymptotically optimal.Comment: Published at http://dx.doi.org/10.1214/009053604000000977 in the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Modeling of transient heat pipe operations

An analysis of the steady, compressible, one-dimensional, laminar flow of sodium vapor is presented for a case of a flat plate-type heat pipe with asymmetrical boundary conditions. In addition, shear stress at the liquid-vapor interface, variations of vapor quality, and momentum and energy factors are considered. A similarity solution for a semiporous channel is used to provide the velocity profile at cross sections

Development of an emulation-simulation thermal control model for space station application

Many features were added to the Thermal Control System (TCS) program to increase its user-friendliness. Several apparent inconsistencies were identified. In some instances, these have led to modifications to the source programs. With the summary line-sizing information, the user can more readily compare the TCS program results with other available data. Two mathematical models were completed: one deals with sizing and analysis of bus heat exchangers and the other provides a means of analyzing a variety of heat pipe radiator designs. A generic heat pipe model was added to the TCS Analysis Program

Development of an emulation-simulation thermal control model for space station application

The goal of this program is to develop an improved capability for comparing various techniques for thermal management in the space station. The work involves three major tasks: Develop a Technology Options Data Base (Task 1); Complete Development of a Space Station Thermal Control Technology Assessment Program (Task 2); and Develop and Evaluate Emulation Models (Task 3)

Communist China\u27s Trade Treaties and Agreements (1949-1964)

Utilizing material gathered by extensive research, the author examines Communist China\u27s trade treaties and agreements, with some emphasis upon their economic and political implications. Also, he analyzes the Communist Chinese use of establishment provisions and national and most-favored-nation treatment. The author has selected the period from 1949 to 1964 due to the existence of an official collection of treaties compiled by the Peking government for this period. Although the collection has not been available since 1964, the authors examination of secondary official source materials has revealed no significant change in the regime\u27s attitude, and therefore, the materials contained in the official collection are considered representative of the present attitudes of the People\u27s Republic of China

A Seasonality Study of the West Virginia Stream Condition Index

The West Virginia Stream Condition Index (WVSCI) has not been rigorously tested for the effects of seasonal data collection. Scientific literature regarding seasonal impacts on biological indices is surprisingly limited. But most literature does agree that seasonal signals are small in comparison to variation between all possible biological conditions. Recently stream data have been collected from a full range of seasons by both West Virginia Department of Environmental Protection and myself. In this study habitat, benthic macroinvertebrate data, and WVSCI values were analyzed for seasonality. For this reason multiple independent data sets were utilized. The analyses covered in this report include the use of box-and-whisker plots, correlation analysis and ANOVAs. Preliminary results indicate that seasonality does impact certain metrics under some seasonal conditions. Among the six metrics that make up the WVSCI, some seasonal signal was detected for EPT Taxa, % Chironomidae, Hilsenhoff Biotic Index, Total Taxa and the WVSCI Index scores. These signals were very inconsistent across multiple, independent data sets. Presently, there are no suggestions for any alterations of the WVSCI that would reduce seasonal signals

Modeling of transient heat pipe operation

Mathematical models and an associated computer program for heat pipe startup from the frozen state have been developed. Finite element formulations of the governing equations are written for each heat pipe region for each operating condition during startup from the frozen state. The various models were checked against analytical and experimental data available in the literature for three specific types of operation. Computations using the methods developed were made for a space shuttle reentry mission where a heat pipe cooled leading edge was used on the wing

Modeling of transient heat pipe operation

The use of heat pipes is being considered as a means of reducing the peak temperature and large thermal gradients at the leading edges of reentry vehicles and hypersonic aircraft and in nuclear reactors. In the basic cooling concept, the heat pipe covers the leading edge, a portion of the lower wing surface, and a portion of the upper wing surface. Aerodynamic heat is mainly absorbed at the leading edge and transported through the heat pipe to the upper and lower wing surface, where it is rejected by thermal radiation and convection. Basic governing equations are written to determine the startup, transient, and steady state performance of a haet pipe which has initially frozen alkali-metal as the working fluid