Smooth empirical Bayes estimation of observation error variances in linear systems.
Abstract missing.
Martz, H. F., Jr.↗
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Functional preservation of vascular smooth muscle tissue
The ionic and cellular feedback relationships operating to effect the vascular decompensatory modifications were examined to reveal procedures for implementing protective measures guarding against vascular collapse when returning from a weightless environment to that of the earth's gravity. The surgical procedures for preparing the rat cremaster, and the fixation methods are described. Abstracts of publications resulting from this research are included.
Alexander, W. C.↗
Analysis of internal flow characteristics of a smooth-disk water-brake dynamometer
The principal of absorbing power with an enclosed partially submerged rotating disk through the turbulent viscous shearing of water is discussed. Reference information is used to develop a flow model of the water brake. A method is then presented that uses vector diagrams to relate the effects of rotational flow, through flow, and secondary flow to power absorption. The method is used to describe the operating characteristics of an example 111-cm (43.7-in.) diameter water brake. Correlating performance parameters are developed in a dimensional analysis.
Evans, D. G.↗
Data smoothing and error detection based on linear interpolation
A method is presented, based on linear interpolation, for detecting and correcting bad data points in a set of data without contaminating the good data points. The method used is not concerned with the small random errors usually attributed to a noisy system. It assumes that the data points which are in error are relatively isolated from each other and that the number of such points is small compared to the total number of data points.
Guerra, V. M.↗
Spline smoothing of histograms by linear programming
An algorithm for an approximating function to the frequency distribution is obtained from a sample of size n. To obtain the approximating function a histogram is made from the data. Next, Euclidean space approximations to the graph of the histogram using central B-splines as basis elements are obtained by linear programming. The approximating function has area one and is nonnegative.
Bennett, J. O.↗
A new approach to the problem of wave fluctuations in localized smoothly varying turbulence.
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Ishimaru, A.↗
The smoothing dissector.
A technique for adding a form of buffer store to an image dissector is described that increases markedly the photoelectron-detecting ability of the image dissector. The buffer-store function is accomplished in the phosphor screen of an image intensifier tube by the metastable electronic excitation states resulting in the phosphor screen from high-energy photoelectron bombardment. The addition of this image intensifier to an image dissector is shown to cause no nonlinearity in the input/output characteristics of the image dissector.
Eberhardt, E. H.↗
Analysis of heat transfer and fluid friction for fully developed turbulent flow of supercritical water with variable fluid properties in a smooth tube
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Deissler, R. G.↗
Plastic covering on airfoil structure provides smooth uninterrupted surface
Primed surface is covered with adhesive. Sheet of plastic film is stretched over adhesive and mechanical holder is used to apply tension to ends of sheet to make it conform to surface of airfoil. After adhesive cures, plastic can be trimmed with sharp cutting tool.
Kinzler, J. A.↗
The meteorological effects on microwave apparent temperatures looking downward over a smooth sea
The effects of clouds and rain on microwave apparent temperatures for a flat sea surface are examined. The presence of clouds and rain can be expressed as a change of absorption coefficient and the total absorption is computed as the sum of individual effects. Various cloud and rain models proposed by meteorologists are employed to compute the microwave apparent temperature when viewing downward through these model atmospheres. It is shown that stratus, cumulus, overcast, and rain all contribute significantly to the observed temperature. Larger sensitivities to clouds and rain are observed for horizontally polarized apparent temperature at large nadir angles than for vertically polarized apparent temperature.
Wu, S.↗
A minimum principle for smooth first-order distributed systems
Consideration of the problem of characterizing optimal controls for a class of distributed parameter systems. The system dynamics are characterized mathematically by a finite number of coupled partial differential equations involving first-order time and space derivatives of the state variables. Boundary conditions on the state are in the form of a finite number of algebraic relations between the state and boundary control variables. A few directions are outlined in which the results obtained may be extended further.
Johnson, T. L.↗
Investigation of smooth specimen scc test procedures; variations in environment, specimen size, stressing frame, and stress state
The variables studied in the stress-corrosion cracking performance of high strength aluminum alloys were: (1) corrosiveness of the environment, (2) specimen size and stiffness of the stressing system, (3) interpretation of transgranular cracking, and (4) interaction of the state of stress and specimen orientation in a product with an anisotropic grain structure. It was shown that the probability of failure and time to fracture for a specimen loaded in direct tension are influenced by corrosion pattern, the stressing assembly stiffness, and the notch tensile strength of the alloy. Results demonstrate that the combination of a normal tension stress and a shear stress acting on the plane of maximum susceptibility in a product with a highly directional grain cause the greatest tendency for stress-corrosion cracking.
Lifka, B. W.↗
Theoretical effect of modifications to the upper surface of two NACA airfoils using smooth polynomial additional thickness distributions which emphasize leading edge profile and which vary quadratically at the trailing edge
An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of the NACA 64-206 and 64 sub 1 - 212 airfoils. The additional thickness distribution had the form of a continuous mathematical function which disappears at both the leading edge and the trailing edge. The function behaves as a polynomial of order epsilon sub 1 at the leading edge, and a polynomial of order epsilon sub 2 at the trailing edge. Epsilon sub 2 is a constant and epsilon sub 1 is varied over a range of practical interest. The magnitude of the additional thickness, y, is a second input parameter, and the effect of varying epsilon sub 1 and y on the aerodynamic performance of the airfoil was investigated. Results were obtained at a Mach number of 0.2 with an angle-of-attack of 6 degrees on the basic airfoils, and all calculations employ the full potential flow equations for two dimensional flow. The relaxation method of Jameson was employed for solution of the potential flow equations.
Merz, A. W.↗
Theoretical effect of modifications to the upper surface of two NACA airfoils using smooth polynomial additional thickness distributions which emphasize leading edge profile and which vary linearly at the trailing edge
An investigation was conducted on a CDC 7600 digital computer to determine the effects of additional thickness distributions to the upper surface of airfoils. The additional thickness distribution had the form of a continuous mathematical function which disappears at both the leading edge and the trailing edge. Results were obtained at a Mach number of 0.2 with an angle of attack of 6 deg. All calculations employed the full potential flow equations for two dimensional flow. The relaxation method of Jameson was used for solution of the potential flow equations. It is shown that increasing the thickness and variations in shape increases the lift and the adverse pitching moment coefficients.
Hague, D. S.↗
An efficient fixed-lag smoothing algorithm for discrete linear systems
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Bierman, G. J.↗
Rough-to-smooth transition of an equilibrium neutral constant stress layer
A model is proposed for low-level atmospheric flows over terrains of changing roughness length, such as those found at the windward end of landing strips adjoining rough terrain. The proposed model is used to develop a prediction technique for calculating transition wind and shear-stress profiles in the region following surface roughness discontinuity. The model for the transition region comprises two layers: a logarithmic layer and a buffer layer. The flow is assumed to be steady, two-dimensional, and incompressible, with neutral hydrostatic stability. A diagram is presented for a typical wind profile in the transition region, obtained from the logarithmic and velocity defect profiles using shear stress calculated by relevant equations.
Logan, E., Jr.↗
Smoothing of orbital tracking data: Mission planning, mission analysis and software formulation
The problem created by the presence of wild or outlying data points among orbital tracking data, is addressed. Consideration is given to the effects of such outliers on the orbit determination process, and methods for minimizing or even eliminating these effects are proposed. Some preliminary efforts implementing these new methods are described, and the results thus far obtained are summarized. Based on these ideas and results, recommendations are made for future investigation.
Vedder, J. D.↗
An optimal smoothing algorithm for Viking spacecraft attitude determination
A fundamental requirement for ground analysis of onboard attitude control systems is the determination of the time evolution of spacecraft angular orientation and velocity, and of external torques acting on the spacecraft. However, at times, there are limitations on the data received on the ground, and essential but missing variables must be estimated. This paper contains a description of the design and implementation of an algorithm for angular position, velocity, and torque estimation. The algorithm has been used to analyze the performance of the Viking Orbiter attitude control system. Typical results of this analysis are presented.
Rodriguez, G.↗