Search NASA⌕ Search

SEARCH · Search NASA

Results for “minimization”

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.

At least 397 records · Page 22
All sourcesNASA NTRSDOE OSTI
NASA NTRS1971

Minimal logic block encoder Patent

Encoders designed to generate comma free biorthogonal Reed-Muller type code comprising conversion of 64 6-bit words into 64 32-bit data for communication purposes

Duffy, J. O.↗
NASA NTRS1972

Transmission of optical frequencies with minimal losses

Application of diffractionless dielectrics as transmitting media between laser beam source and receiver is discussed. Optical properties of transmitting media are described and general system diagram is illustrated. Use of system in power transmission, communications, surgery, and machinery is explained.

Townes, C. H.↗
NASA NTRS1971

Sonic boom generation propagation and minimization.

Factors influencing the generation and propagation of sonic boom are discussed, covering predictions of sonic boom levels, effects of atmospheric conditions, and effects of ground characteristics. Also discussed are experimental techniques for sonic boom studies, and approaches to the reduction of sonic boom signatures.

Ferri, A.↗
NASA NTRS1972

Sonic boom generation propagation and minimization.

Consideration of the possibility of reducing sonic boom noise to a level acceptable in populated areas. A detailed study is made of the possibility of predicting sonic boom generation, taking into account the effect of atmospheric conditions, air turbulence, and the effect of the shape and condition of the ground where people are located. The relation between the shape of the sonic boom signature on the ground and the aircraft shape is shown to be an important factor governing the use of supersonic aircraft over populated areas.

Ferri, A.↗
NASA NTRS1973

Minimal hardware, binary sequence pseudonoise generator and detector

General purpose sequence generator which includes 35-stage field shift register determines mathematical properties of polynomials such as divisibility, period, order of roots, and other parameters that effect desirability of various sequences for specific applications; for example, irreducible polynomials which characterize sequences with randomness properties.

Perlman, M.↗
NASA NTRS1974

Design method for minimizing RF voltage breakdown

Research study was conducted and results were published. Using principles of similarity and minimum of experimental data, a number of universal curves have been constructed covering wide range of experimental parameters. Gases other than air, such as argon and carbon dioxide, also are included in study.

Woo, R. T.↗
NASA NTRS1972

Minimizing the area required for time constants in integrated circuits

When a medium- or large-scale integrated circuit is designed, efforts are usually made to avoid the use of resistor-capacitor time constant generators. The capacitor needed for this circuit usually takes up more surface area on the chip than several resistors and transistors. When the use of this network is unavoidable, the designer usually makes an effort to see that the choice of resistor and capacitor combinations is such that a minimum amount of surface area is consumed. The optimum ratio of resistance to capacitance that will result in this minimum area is equal to the ratio of resistance to capacitance which may be obtained from a unit of surface area for the particular process being used. The minimum area required is a function of the square root of the reciprocal of the products of the resistance and capacitance per unit area. This minimum occurs when the area required by the resistor is equal to the area required by the capacitor.

Lyons, J. C.↗
NASA NTRS1972

Coordinate transformation by minimizing correlations between parameters

This investigation was to determine the transformation parameters (three rotations, three translations and a scale factor) between two Cartesian coordinate systems from sets of coordinates given in both systems. The objective was the determination of well separated transformation parameters with reduced correlations between each other, a problem especially relevant when the sets of coordinates are not well distributed. The above objective is achieved by preliminarily determining the three rotational parameters and the scale factor from the respective direction cosines and chord distances (these being independent of the translation parameters) between the common points, and then computing all the seven parameters from a solution in which the rotations and the scale factor are entered as weighted constraints according to their variances and covariances obtained in the preliminary solutions. Numerical tests involving two geodetic reference systems were performed to evaluate the effectiveness of this approach.

Kumar, M.↗
NASA NTRS1973

Minimizing boundary layer bleed for a mixed compression inlet

An experimental investigation of a full scale mixed compression inlet sized for the TF30-P-3 turbofan engine was conducted at Mach 2.5 and 2.0 operating conditions. The two cone axisymmetric inlet had minimum internal contraction consistent with high total pressure recovery and low cowl drag. At Mach 2.5, inlet recovery exceeded 0.90 with only 0.02 centerbody bleed mass-flow ratio and zero cowl bleed. A centerbody bleed of approximately 0.05 gave a maximum inlet unstart angle-of-attack of 6.85 deg. Inlet performance and angle-of-attack tolerance is presented for operation at Mach 2.5 and 2.0.

Wasserbauer, J. F.↗
NASA NTRS1973

Measuring and minimizing the social cost of environmental pollution

The various impacts to the environmental protection movement on the largest corporations in several industries which had the most serious pollution problem are discussed. The purpose was to examine the impacts from the point of view of top corporation managers so that a broader perspective could be provided for all concerned parties- citizens, environmentalists, legislators, governmental administrators and agency personnel, scientists, engineers, and other industrial managers.

Henry, H. W.↗
NASA NTRS1974

Parametric study of STOL short-haul transport engine cycles and operational techniques to minimize community noise impact

The effect of aircraft operational techniques in the terminal area on community noise impact of future short haul aircraft was investigated. Aircraft equipped with mechanical flap (MF) and aircraft with externally blown flap (EBF) were used to study the noise impact at four U.S. airports. The four airports were: (1) Hanscom Field (Boston), (2) Washington National (D.C.), (3) Midway (Chicago) and (4) Orange County (California). With the exception of Washington National (D.C.), the study showed that a reduction of approximately 40 percent in the number of people highly annoyed can be obtained by using the recommended operational techniques. The evaluation procedures and methodology developed in the study represent an advance in acoustical state-of-the-art and provide an effective and useful tool for determining aircraft noise impact on the airport community.

Source record↗
NASA NTRS1973

Minimizing boundary layer bleed for a mixed compression inlet

An experimental investigation of a full scale mixed compression inlet sized for the TF30-P-3 turbofan engine was conducted at Mach 2.5 and 2.0 operating conditions. The two cone axisymmetric inlet had minimum internal contraction consistent with high total pressure recovery and low cowl drag. At Mach 2.5, inlet recovery exceeded 0.90 with only 0.02 centerbody bleed mass-flow ratio and zero cowl bleed. A centerbody bleed of approximately 0.05 gave a maximum inlet unstart angle-of-attack of 6.85 deg. Inlet performance and angle-of-attack tolerance is presented for operation at Mach 2.5 and 2.0.

Wasserbauer, J. F.↗
NASA NTRS1973

Homogeneity requirements for minimizing self-focusing damage by strong electromagnetic waves

The Rytov approximation for wave propagation in random media is generalized to include the effects of self-focusing. Solutions are obtained which show how the intensity fluctuations, which are either initially present in the wave or which are induced by the random inhomogeneities in the media, grow catastrophically. These solutions may be used to obtain conditions on the homogeneity of the medium, or of the incident beam, for reduction or elimination of catastrophic self-focusing in the medium.

Jokipii, J. R.↗