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Distributions and intercorrelations of 100 variables selected from physiological, personal history, and psychological measures of 1963 evaluation in Pensacola thousand aviator study
The Monte Carlo procedure is a model sampling technique. A model is established, and the behavior of sample units in this model is followed. A sufficient number of sample units are followed to obtain a statistical average or macroscopic quantities, which are the quantities of interest. This technique was used in crude form by Fermi in connection with the building of the first atomic pile. Later, Von Neumann and Ulam developed and used the Monte Carlo procedure extensively in developing the atomic bomb. Since then this technique has gained considerable use in nuclear reactor problems (refs. 1 and 2), and we at the Lewis Research Center have been extending it to thermal radiation (refs. 3 and 4), rarefied gas flows, and plasma flow problems (ref. 5). This technique, which requires a large number of sample histories to obtain solutions with small variances, is receiving greater use because of the development of the high-speed electronic computers.
Time-domain and frequency domain statistics for random step-wise sampled data systems
Quantitative multivariate statistical analysis of average evoked potentials and application to visual stimulus intensity and duration
Omnidirectional characteristics of scattering of acoustic waves from statistically rough surfaces, measuring scattering cross section as function of incidence and observation angles
Quantile system of data compression for space telemetry, discussing operation, efficiency and advantages
Laser quasi-schlieren system and laser shadow-correlation system retrieve flow-related signals sufficient for computing accurate, reproducible correlation peaks. Statistical method for obtaining one-shot measurements of the decay history of turbulent structures in a stationary frame of reference is discussed.
Results of an autocorrelation analysis of the Mariner 2 data concerning solar-wind speed obtained in late 1962. A statistically significant correlation associated with the solar rotation has been found near a lag of 27 days; however, the amplitude of the correlation is only about 0.4, in essential agreement with measurements of Vela 2 and 3 during the period from July 1964 to July 1967. The relatively modest correlation is interpreted to mean that a number of speed structures observed by Mariner 2 did not endure for more than one solar rotation; those structures that did endure evolved significantly in shape, amplitude, and solar longitude from one solar rotation to the next. The analysis also shows that typical solar-wind structures occupied about 30 to 45 deg in solar longitude near 1 AU.
Image interpretation procedures for determining range yield and for extrapolating range information were investigated for an area of the Pine Ridge Indian Reservation in southwestern South Dakota. Soil and vegetative data collected in the field utilizing a grid sampling design and digital film data from color infrared film and black and white films were analyzed statistically using correlation and regression techniques. The pattern recognition techniques used were K-class, mode seeking, and thresholding. The herbage yield equation derived for the detailed test site was used to predict yield for an adjacent similar field. The herbage yield estimate for the adjacent field was 1744 lbs. of dry matter per acre and was favorably compared to the mean yield of 1830 lbs. of dry matter per acre based upon ground observations. Also an inverse relationship was observed between vegetative cover and the ratio of MSS 5 to MSS 7 of ERTS-1 imagery.
Estimates of per cent ground cover made by ground observers were compared with independent estimates made on the basis of low-altitude (640-1219 m) aerial photographs of the same fields. Standard statistical simple correlation and linear regression analyses revealed a high correlation between the two estimation methods. In crops such as grain, sorghum, corn, and forage sorghum, in which the broadest part of the leaf canopy is near the top of the plant, there was a tendency to overestimate the per cent ground cover from aerial photographs.
The effect of variations in tidal stresses on the earth caused by the sun and moon on volcanic activity and climate is investigated. A statistically significant correlation is found between the derivatives of the envelopes of peak tidal stresses at high northern latitudes and the mean temperature of the Northern Hemisphere as reflected in oxygen isotope ratios in the Greenland ice cap. It is suggested that variations in tidal stresses cause changes in the amount of stratospheric dust produced by volcanic activity, which affects the thickness of the stratospheric dust veil and the atmospheric radiation balance. For a simple model, periodic variations in tidal stress account for 13% of the variance in the ice-core temperature record.
The vertical nonhomogeneous character of turbulence in the atmospheric boundary layer results in a non-stationary turbulence process relative to an aircraft during takeoff and landing despite the fact that the turbulence statistics can be horizontally homogeneous. The simulation of the three components of the turbulent winds which include the nonstationary aspect of atmospheric turbulence is the subject of this paper. A procedure is developed and demonstrated to generate the three components of a turbulence ramdom process field, u sub i(x,z) where x and z denote horizontal and vertical coordinates and u sub i, i = 1,2,3 are the three orthogonal components of the turbulent random field. This field satisfies any desired one point auto spectra as well as two point statistics (interlevel correlations). By use of Taylors frozen eddy hypothesis we can transform the turbulent random field into the time domain and obtain the random turbulence along an aircraft trajectory.
Observational evidence favoring the local regulation of solar-wind heat flux at 1 AU is reviewed, and four months of IMP 6 plasma and magnetic-field data are merged and analyzed in order to investigate what might be regulating the heat flux. A statistical analysis of the data shows that the solar-wind Alfven speed is probably regulating the heat flux locally at 1 AU and that the Alfven speed, the velocity difference between the peak of low-energy electrons and the bulk plasma velocity, and the solar-wind velocity component projected along the local spiral angle are statistically well correlated for Alfven speeds not exceeding about 70 km/s. A time-series analysis of the data indicates that only the Alfven speed and the velocity difference between the peak of low-energy electrons and the bulk plasma velocity are well correlated both qualitatively and quantitatively on a microscopic time scale. It is strongly suggested that, at times, the solar-wind heat flux is locally regulated by the magnitude of the Alfven speed at 1 AU. Uncertainties in the results are discussed.
Multispectral scanner data, acquired over several Colorado lakes using LANDSAT-1 and aircraft, were used in conjunction with contact-sensed water quality data to determine the feasibility of assessing lacustrine trophic levels. A trophic state index was developed using contact-sensed data for several trophic indicators. Relationships between the digitally processed multispectral scanner data, several trophic indicators, and the trophic index were examined using a supervised multispectral classification technique and regression techniques. Statistically significant correlations exist between spectral bands, several of the trophic indicators and the trophic state index. Color-coded photomaps were generated which depict the spectral aspects of trophic state.
Multispectral scanner data, acquired over several Colorado lakes using Landsat-1 and aircraft, were used in conjunction with National Eutrophication Survey contact-sensed data to determine the feasibility of assessing lacustrine trophic levels. A trophic state index was developed using contact-sensed data for several trophic indicators (chlorophyll a, inverse of Secchi disk transparency, conductivity, total phosphorous, total organic nitrogen, algal assay yield). Relationships between the digitally processed multispectral scanner data, several trophic indicators, and the trophic index were examined using a supervised multispectral classification technique and regression techniques. Statistically significant correlations exist between spectral bands, several of the trophic indicators (chlorophyll a, Secchi disk transparency, total organic nitrogen), and the trophic state index. Color-coded photomaps were generated which depict the spectral aspects of trophic state. Multispectral scanner data acquired from satellite and aircraft platforms can be used to advantage in lake monitoring and survey programs.
Visual analysis of HCMM images acquired over two sites in Canada and supporting aircraft and ground data obtained at a smaller subsite in Alberta show that nightime surface temperature distribution is primarily related to the near-surface air temperature; the effects of topography, wind, and land cover were low or indirect through air temperature. Surface cover and large altitudinal differences were important parameters influencing daytime apparent temperature values. A quantitative analysis of the relationship between the antecedent precipitation index and the satellite thermal IR measurements did not yield statistically significant correlation coefficients, but the correlations had a definite temporal trend which could be related to the increasing uniformity of vegetation cover. The large pixel size (resulting in a mixture of cover types and soil/canopy temperatures measured by the satellite) and high cloud cover frequency found in images covering both Canadian sites and northern U.S. were considered the main deficiencies of the thermal satellite data.
The geologic framework of the intercrater plains on Mercury and the Moon as determined through geologic mapping is presented. The strategies used in such mapping are discussed first. Then, because the degree of crater degradation is applied to both mapping and crater statistics, the correlation of degradation classification of lunar and Mercurian craters is thoroughly addressed. Different imaging systems can potentially affect this classification, and are therefore also discussed. The techniques used in mapping Mercury are discussed in Section 2, followed by presentation of the Geologic Map of Mercury in Section 3. Material units, structures, and relevant albedo and color data are discussed therein. Preliminary conclusions regarding plains' origins are given there. The last section presents the mapping analyses of the lunar intercrater plains, including tentative conclusions of their origin.
The average upper mantle compressional wave velocity and heat flow figures presently computed for continental physiographic provinces in North America exhibit an inverse relationship, and possess a statistically significant correlation coefficient. A correlation is also demonstrated between compressional wave velocity and material temperature by estimating crust-mantle boundary temperatures from heat flow values. The dependency of compressional wave velocity on temperature implies that the observed geographical distribution in upper mantle seismic velocity may be due to the temperature effect character of upper mantle compressional wave velocity variation.