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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.
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Effect of nodal regression of orbit on gravity gradient precession of gyroscopic satellite in testing general theory of relativity
Orbital regression of synchronous satellites due to combined gravitational effects of sun, moon, and oblate earth
Classification of experimental designs relative to polynomial spline regression functions
Regression analysis procedures for evaluating tracking system measurement errors
Aspects of human operator performance in low order compensatory control tasks studied with regression analysis
Systematic investigation of mathematical models by comparison of experimental and analytical regression coefficients
Regression rate model for pressure sensitive hybrid combustion based on classical turbulent flame theory
Curve fitting for modified paired comparisons using linearized nonlinear regression
FORTRAN 4 program for multiple linear regression analysis
Analysis of fuel thermal conductivity effects on melt layer buildup and regression rates in hybrid and tribrid propellant rocket engines
Multidimensional integral Monte Carlo evaluation applying regression analysis to linear unbiased estimators
Multivariate regression analysis of atmospheric density in region 30 to 100 km
Regression analysis procedure for evaluating reliability of nondestructive refractory coating thickness measurements
Two computer programs developed according to two general types of exponential models for conducting nonlinear exponential regression analysis are described. Least squares procedure is used in which the nonlinear problem is linearized by expanding in a Taylor series. Program is written in FORTRAN 5 for the Univac 1108 computer.
A computer-oriented technique is presented for performing a nonlinear exponential regression analysis on decay-type experimental data. The technique involves the least squares procedure wherein the nonlinear problem is linearized by expansion in a Taylor series. A linear curve fitting procedure for determining the initial nominal estimates for the unknown exponential model parameters is included as an integral part of the technique. A correction matrix was derived and then applied to the nominal estimate to produce an improved set of model parameters. The solution cycle is repeated until some predetermined criterion is satisfied.
Classical iterative methods in nonlinear regression are reviewed and improved upon. This is accomplished by discussion of the geometrical and theoretical motivation for introducing modifications using generalized matrix inversion. Examples having inherent pitfalls are presented and compared in terms of results obtained using classical and modified techniques. The modification is shown to be useful alone or in conjunction with other modifications appearing in the literature.
Comparison of two-impulse and three-impulse orbital transfer, using data from a 63-case numerical study. For each case investigated for which coplanarity of the regressing assembly parking ellipse was attained with the target asymptotic velocity vector, a two-impulse maneuver (or a one-impulse equivalent) was found for which the velocity expenditure was within 1% of a reference absolute minimum lower bound. Therefore, for the coplanar cases, use of a minimum delta-V three-impulse maneuver afforded scant improvement in velocity penalty. However, as the noncoplanarity of the parking ellipse and the target asymptotic velocity vector increased, there was a significant increase in the superiority of minimum delta-V three-impulse maneuvers for slowing the growth of velocity expenditure. It is concluded that a multiple-impulse maneuver should be contemplated if nonnominal launch conditions could occur.
Classical iterative methods in nonlinear regression are reviewed and improved upon. This is accomplished by discussion of the geometrical and theoretical motivation for introducing modifications using generalized matrix inversion. Examples having inherent pitfalls are presented and compared in terms of results obtained using classical and modified techniques. The modification is shown to be useful alone or in conjunction with other modifications appearing in the literature.