SEARCH · Search NASA
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.
Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.
Midcourse navigation using statistical filter theory, manual theodolite, and symbolic computer control applied to manned spacecraft
Computer program for symbolic reduction of block diagrams to obtain transfer functions
Computer determination of symbolic state equations for nonlinear circuits using FORTRAN notation
Digital transition tracking symbol synchronizer for low SNR coded telemetry systems, discussing phase locked loop analysis and phase detector simulation by Monte Carlo method
Symbolic programming system for computer processing of algebraic expressions
Riemann tensor symbolic computation by compact method using differential forms, discussing advantages due to antisymmetry
Computerized FORTRAN equations simulation of linear and nonlinear circuits for symbolic analysis and transient response
Topological symbolic analysis of circuits defined by topological constraints, utilizing digital computers
Digital transition tracking symbol synchronizer improving SNR without lowering loop bandwidth
Cosmology application of mathematical modeling by symbolic computation
Investigating symbolic mathematical computation using PL/1 FORMAC batch system and Scope FORMAC interactive system
Investigating symbolic computations by finite field theory using FORMAC system
Discussing problem of symbolic numeric conversion in solving quantum mechanical eigenvalue problems with FORMAC
Investigating problem of formulating symbolic integration of elementary functions
Symbolic method for solving linear equations of flow graphs by multivariate polynomial extension of two-step integer-preserving elimination algorithm
Discussing problems in design and implementation of practical batch processing systems for performing symbolic mathematical computation
Algorithms for accessing symbol tables in compiler
REDUCE 2 is reported as a FORMAC program which symbolically calculates the transfer function(s) of any linear-block-diagram output variable to any or all input variables. The program requires as input a set of algebraic expressions representing the block diagram, the desired transfer function(s), and a string of variables indicating the desired order of reduction. The solution is presented in the compact form of a set of nested functions (super G's). The program can handle systems as large as 600 equations and is intended as a tool for the analysis of complex control and dynamic systems. A companion FORTRAN program, EVAL 2, which numerically evaluates the solution set to obtain amplitude ratio and phase angle as functions of frequency is also presented.