Chebyshev polynomial expansion of Bose- Einstein functions of orders 1 to 10.
Chebyshev series approximations for Bose- Einstein functions of orders one to ten, noting computability of Fermi-Dirac functions and polylogarithms
Devine, C. J.↗
SEARCH · Engineering Papers
Results for “function”
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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Spherical wave functions and certain of their properties
Spherical wave functions, Legendre and Bessel functions, and addition theorems
Source record↗
Analysis of irrational transfer functions for distributed-parameter systems
Algorithmic and digital computer method for approximating irrational transfer functions by rational functions in control systems
Chen, C.-F.↗
The delta function approximation in radiative transfer theory
Delta function approximation in diffuse transmission and reflection of light for phase function with sharp forward peak, using scattering compensation
Potter, J. F.↗
Projected Hartree-Fock spectra with Wood- Saxon basis functions
Investigating short-range behavior of wave function by comparing projected Hartree-Fock spectra using basis functions having harmonic oscillator and Wood-Saxon radial dependence
Braley, R. C.↗
Experimental evaluation of four transfer functions for a single tube boiler which are dynamically independent of exit restrictions
Experimental evaluation of four transfer functions for single tube boiler and demonstration of functions being independent of exit restrictions
Goodykoontz, J. H.↗
Potential functions in pattern classification algorithms
Pattern classification algorithms using potential functions to construct discriminant functions from sample points set
Meisel, W. S.↗
Computer method for identification of boiler transfer functions
Iterative computer aided procedure was developed which provides for identification of boiler transfer functions using frequency response data. Method uses frequency response data to obtain satisfactory transfer function for both high and low vapor exit quality data.
Miles, J. H.↗
Vibrational transfer functions for complex structures
Evaluation of effects of vibrational multiple frequency forcing functions is discussed. Computer program for developing vibrational transfer functions is described. Possible applications of computer program are enumerated.
Jones, P. A.↗
Crew interface specification development study for in-flight maintenance and stowage functions
The need and potential solutions for an orderly systems engineering approach to the definition, management and documentation requirements for in-flight maintenance, assembly, servicing, and stowage process activities of the flight crews of future spacecraft were investigated. These processes were analyzed and described using a new technique (mass/function flow diagramming), developed during the study, to give visibility to crew functions and supporting requirements, including data products. This technique is usable by NASA for specification baselines and can assist the designer in identifying both upper and lower level requirements associated with these processes. These diagrams provide increased visibility into the relationships between functions and related equipments being utilized and managed and can serve as a common communicating vehicle between the designer, program management, and the operational planner. The information and data product requirements to support the above processes were identified along with optimum formats and contents of these products. The resulting data product concepts are presented to support these in-flight maintenance and stowage processes.
Carl, J. G.↗
Determination of atmospheric structure function by using a single coherent detector
A technique is described and analyzed for using the single beam laser receiver to measure the wave structure function of atmospheric turbulence. The measurement procedure is as follows: first, the telescope aperture is masked with an opaque screen having two small holes; one hole is covered and the output of the laser receiver is measured; finally, the output of the laser receiver is measured with both holes uncovered. By repeating these measurements for different hole separations, the wave structure function can be derermined.
Lang, R. H.↗
Constrained Chebyshev approximations to some elementary functions suitable for evaluation with floating point arithmetic
Approximations which can be evaluated with precision using floating-point arithmetic are presented. The particular set of approximations thus far developed are for the function TAN and the functions of USASI FORTRAN excepting SQRT and EXPONENTIATION. These approximations are, furthermore, specialized to particular forms which are especially suited to a computer with a small memory, in that all of the approximations can share one general purpose subroutine for the evaluation of a polynomial in the square of the working argument.
Manos, P.↗
Nth-order flat approximation of the signum function by a polynomial
In the interval studied, the signum function, sgn x, was demonstrated to be uniquely approximated by an odd polynomial f sub n (x) of order 2n-1, for which the approximation is nth order flat with respect to the points (1,1) and (-1,-1). A theorem was proved which states that for even integers n or = 2, the approximating polynomial has a pair of nonzero real roots + or - x sub n such that the x sub n form a monotonically decreasing sequence which converges to the root of 2 as n approaches infinity. For odd n i, f sub n (x) represents a strictly increasing monotonic function for all real x. As n tends to infinity, f sub n (x) converges to sgn x uniformly in two interval ranges.
Hosenthien, H. H.↗
Functional requirements for design of the Space Ultrareliable Modular Computer (SUMC) system simulator
The functional requirements for the design of an interpretive simulator for the space ultrareliable modular computer (SUMC) are presented. A review of applicable existing computer simulations is included along with constraints on the SUMC simulator functional design. Input requirements, output requirements, and language requirements for the simulator are discussed in terms of a SUMC configuration which may vary according to the application.
Curran, R. T.↗
Advanced Software Techniques for Data Management Systems. Volume 2: Space Shuttle Flight Executive System: Functional Design
A functional design of software executive system for the space shuttle avionics computer is presented. Three primary functions of the executive are emphasized in the design: task management, I/O management, and configuration management. The executive system organization is based on the applications software and configuration requirements established during the Phase B definition of the Space Shuttle program. Although the primary features of the executive system architecture were derived from Phase B requirements, it was specified for implementation with the IBM 4 Pi EP aerospace computer and is expected to be incorporated into a breadboard data management computer system at NASA Manned Spacecraft Center's Information system division. The executive system was structured for internal operation on the IBM 4 Pi EP system with its external configuration and applications software assumed to the characteristic of the centralized quad-redundant avionics systems defined in Phase B.
Pepe, J. T.↗
A Theory for the Function of the Spermaceti Organ of the Sperm Whale (Physeter Catodon L.)
The function of the spermaceti organ of the sperm whale is studied using a model of its acoustic system. Suggested functions of the system include: (1) action as an acoustic resonating and sound focussing chamber to form and process burst-pulsed clicks; (2) use of nasal passages in forehead for repeated recycling of air for phonation during dives and to provide mirrors for sound reflection and signal processing; and (3) use of the entire system to allow sound signal production especially useful for long range echolocofion in the deep sea.
Norris, K. S.↗
Determination of work functions near melting points of refractory metals by using a direct-current arc
Effective work functions of refractory metals at temperatures near their melting points were determined by using a direct-current arc. A metal wire connected as the cathode was melted by striking an arc discharge in an argon atmosphere. A melted sphere was formed with a definite emitting area which was calculated from the sphere diameter measured after terminating the arc. Effective work functions were calculated from the Richardson-Dushman equation by using this emission area. The procedure is experimentally advantageous because surface cleanliness of the specimen is not critical, high vacuum is not required, and the anode-cathode spacing is not critical.
Gordon, W. A.↗
The response of a 0.03-cm silicon detector to a mixed neutron and gamma field as a function of shield material and thickness
The neutron and gamma radiation from a MHW-RTG was used to evaluate the total response of a shielded 0.3-mm silicon detector. The generator employs a 2200 W(th) PuO2 heat source concept known as the HELIPAK. The total integrated neutron and gamma ray fluxes at 100 cm away from the source along the radial direction were 1.67 x 1,000 n/sq cm/s and 1.49 x 10,000 gamma sq cm/s, respectively. Experimental values of the response function of the shielded silicon detector were used to determine the total counting rates due to photons at bias energies ranging from 50 to 200 keV. For neutrons, analytically computed response functions were used to determine the total counting rates at the same bias energies. It was found that for an aluminum shield the neutrons are not significant, regardless of the thickness of the shield. However, the magnitude of the total counting rate due to neutrons increases with increased atomic number of the shield and becomes comparable to the counting rate due to photons for a platinum shield thickness of 5 cm.
Taherzadeh, M.↗