Predictive Models and Calibration Analysis in Large-Scale Computational Studies.

Computational modeling and simulation are used to study many complex phenomena where physical experiments are not feasible or too expensive. Examples include climate models, nuclear stockpile analysis, design and manufacturing of complex systems, and biological systems. Statistical methods play a crucial role in this area, ranging from the design of computer experiments and analysis of the outputs to developing statistical emulators, calibration analysis and, more generally, uncertainty quantification. This dissertation deals with two aspects of these statistical problems. The first part is concerned with statistical emulators. In most applications of interest, a statistical model is fit to the output from limited number of evaluations of the computational model, and the resulting “emulator" is used to approximate the input-output relationship. The method of choice is a Gaussian Spatial Process (GaSP), where the output is viewed as the realization of a Gaussian process. While GaSP can be implemented using frequentist methods, it is most commonly used within a Bayesian framework. We compare the performance of GaSP with flexible regression-based approaches. These include existing methods such as multivariate adaptive regression splines (MARS), smoothing-spline anova (SS-ANOVA), multiple adaptive regression tree model (MART), and two methods developed in this dissertation: expanded multivariate adaptive regression splines model (EMARS) and smoothing spline model with a kernel function based on exponential products (SS-Prod). Our empirical comparisons show that EMARS has better predictive performance than GaSP in a variety of situations. The EMARS can be implemented with the current MARS algorithm. Given its computational advantage, it can be applied to computational models with a larger number of input parameters. The second part of thesis focuses on the calibration problem, where we have to determine the true (but unknown) values of certain input parameters to the computational model. This is a challenging inverse problem that suffers from identifiability issues. We develop conditions for determining identifiability and examine data-based approaches for checking the conditions in practice. The behavior of the methods is examined in various situations.PhDStatisticsUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/107103/1/zyzhang_1.pd

NASA Tech Briefs, November/December 1987

Topics include: NASA TU Services; New Product Ideas; Electronic Components and Circuits; Electronic Systems; Physical Sciences; Materials; Computer Programs; Mechanics; Fabrication Technology; Machinery; Mathematics and Information Sciences; Life Sciences

Air Force Institute of Technology Research Report 2017

This Research Report presents the FY18 research statistics and contributions of the Graduate School of Engineering and Management (EN) at AFIT. AFIT research interests and faculty expertise cover a broad spectrum of technical areas related to USAF needs, as reflected by the range of topics addressed in the faculty and student publications listed in this report. In most cases, the research work reported herein is directly sponsored by one or more USAF or DOD agencies. AFIT welcomes the opportunity to conduct research on additional topics of interest to the USAF, DOD, and other federal organizations when adequate manpower and financial resources are available and/or provided by a sponsor. In addition, AFIT provides research collaboration and technology transfer benefits to the public through Cooperative Research and Development Agreements (CRADAs)

National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program 1988, volume 1

The 1988 Johnson Space Center (JSC) National Aeronautics and Space Administration (NASA)/American Society for Engineering Education (ASEE) Summer Faculty Fellowship Program was conducted by the University of Houston and JSC. The 10-week program was operated under the auspices of the ASEE. The program at JSC, as well as the programs at other NASA Centers, was funded by the Office of University Affairs, NASA Headquarters, Washington, D.C. The objectives of the program, which began in 1965 at JSC and in 1964 nationally, are (1) to further the professional knowledge of qualified engineering and science faculty members; (2) to stimulate an exchange of ideas between participants and NASA; (3) to enrich and refresh the research and teaching activities of participants' institutions; and (4) to contribute to the research objectives of the NASA Centers

Space station systems: A bibliography with indexes (supplement 9)

This bibliography lists 1,313 reports, articles, and other documents introduced into the NASA scientific and technical information system between January 1, 1989 and June 30, 1989. Its purpose is to provide helpful information to researchers, designers and managers engaged in Space Station technology development and mission design. Coverage includes documents that define major systems and subsystems related to structures and dynamic control, electronics and power supplies, propulsion, and payload integration. In addition, orbital construction methods, servicing and support requirements, procedures and operations, and missions for the current and future Space Station are included

SPICA:revealing the hearts of galaxies and forming planetary systems : approach and US contributions

How did the diversity of galaxies we see in the modern Universe come to be? When and where did stars within them forge the heavy elements that give rise to the complex chemistry of life? How do planetary systems, the Universe's home for life, emerge from interstellar material? Answering these questions requires techniques that penetrate dust to reveal the detailed contents and processes in obscured regions. The ESA-JAXA Space Infrared Telescope for Cosmology and Astrophysics (SPICA) mission is designed for this, with a focus on sensitive spectroscopy in the 12 to 230 micron range. SPICA offers massive sensitivity improvements with its 2.5-meter primary mirror actively cooled to below 8 K. SPICA one of 3 candidates for the ESA's Cosmic Visions M5 mission, and JAXA has is committed to their portion of the collaboration. ESA will provide the silicon-carbide telescope, science instrument assembly, satellite integration and testing, and the spacecraft bus. JAXA will provide the passive and active cooling system (supporting the