Reduction of machine time in discrete ordinates calculations
Two dimensional Sn computer code for reactor kinetics calculations in data reduction
Albers, L. K.↗
SEARCH · Engineering Papers
Results for “discretization”
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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Dual-rate finite-settling-time discrete systems
Finite settling time for feedback control systems using dual rate, sampled data control algorithm
Gatlin, J. A.↗
Automatic error correcting in discrete automata
Self correcting codes for structural redundancy and reliability of automata
Frantsis, T. A.↗
Estimation of the mean of a discrete parameter, covariance stationary, stochastic process in rotation sampling
Constrained optimization procedure for deriving linear estimator of population mean in rotation sampling
Nishikawa, K.-Y.↗
Cold-air investigation of a turbine with transpiration-cooled stator blades. 1 - Performance of stator with discrete hole blading
Transpiration coolant ejection effects on stator mass flow and efficiency
Prust, H. W., Jr.↗
Discrete local altitude sensing device Patent
Device for use in descending spacecraft as altitude sensor for actuating deceleration retrorockets
Campbell, C. C., Jr.↗
Discrete element methods for the plastic analysis of structures subjected to cyclic loading
Electron bombardment produced clustered displacements, paired vacancies and interstitial atoms in Si, discussing possible mechanism for developing defects
Armen, H., Jr.↗
Design of finite settling time discrete systems
Finite settling response for single input/output feedback control system obtained by dual rate sampled data control algorithm
Gatlin, J. A.↗
Solar coronal streamers. II - Evolution of discrete features from the sun to 1 AU
Coronal streamers structure and evolution from photographic and K-coronameter data, indicating photospheric bipolar magnetic regions as origin
Bohlin, J. D.↗
Discrete-component S-band power amplifier
Amplifier uses low Q input and output circuitry incorporating four variable air dielectric capacitors. Performance over conventional designs includes - increased power output, decreased likelihood of parametric oscillation, and increased thermal stability.
Line, L. G.↗
Application of empirical Bayes decision procedures to discrete time linear filtering. Investigation of an empirical Bayes filter for use in trajectory estimation Final report
Empirical Bayes filter for use in trajectory estimation and comparison of performance with Kalman filter
Kamat, S. J.↗
Low-Energy Electron Transport with the Method of Discrete Ordinates
One-dimensional code adaptation for electron transport
Bartine, D. E.↗
Accelerated procedures for the solution of discret e Markov control problems
Accelerated procedures for Markov chain model optimal control problems solution with computation time advantage over usual dynamic programming
Kleinman, A. J.↗
Empirical Bayes state estimation in discrete time linear systems
Linear dynamic systems state estimation, using empirical Bayes decision theory to develop filter set
Kamat, S. J.↗
Boundedness regions of discrete-time dynamic systems
Techniques for obtaining quantitative information about boundedness properties are developed and applied to the sampled-data control of satellite attitude with quantization. Relevant stability concepts are introduced as a series of definitions, and interrelationships between various definitions are discussed. The boundedness regions are estimated by means of quadratic Liapunov functions, and a sufficient condition for the existence of a boundedness region is given for a certain class of systems. A quadratic Liapunov function is applied to the Lur'e-Postinkov class of systems, where the linear part of the system is not asymptotically stable and the quantizer represents the nonlinear characteristic. A numerical calculation of the region of boundedness estimates is performed for satellite attitude control and is compared with simulation results. It is tentatively concluded that the Liapunov results may be good and that simulation results may be difficult to interpret and time-consuming to generate. The Lur'e-based technique yields estimates of regions of absolute boundedness, but at the cost of greater analytical complexity.
Siljak, D.↗
Convergence of the discretization equations which arise in stochastic control
A problem is considered which arises in the numerical analysis of the degenerate partial differential equations of stochastic control theory. The relationship between diffusions and finite state Markov chains is considered. The role of probability theory in numerical analysis is illustrated.
Kushner, H. J.↗
Discrete square root filtering - A survey of current techniques.
Current techniques in square root filtering are surveyed and related by applying a duality association. Four efficient square root implementations are suggested, and compared with three common conventional implementations in terms of computational complexity and precision. It is shown that the square root computational burden should not exceed the conventional by more than 50% in most practical problems. An examination of numerical conditioning predicts that the square root approach can yield twice the effective precision of the conventional filter in ill-conditioned problems. This prediction is verified in two examples.
Kaminskii, P. G.↗
A discrete variable approximation to minimum weight panel designs subject to a supersonic flutter-speed constraint.
A numerical technique is presented that determines the minimum-weight thickness distribution for a one-dimensional, simply supported panel subjected to a parallel supersonic flow on one side. An aeroelastic eigenvalue, which characterizes flutter speed, is held constant. The governing differential equations are approximated by sets of difference equations adjoined to the weight function via a penalty function. A conjugate gradient method then solves the resulting sequence of unconstrained minimization problems. Numerical results are obtained without imposing a minimum thickness constraint; the effect of constant inplane tensile and compressive stresses is also investigated.
Pierson, B. L.↗