Gradient methods in control theory. Part 5 - Sequential gradient-restoration algorithm, additional numerical examples
Numerical examples for sequential gradient restoration algorithm
Damoulakis, J. N.↗
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Parametric design of interplanetary and orbital trajectories with examples for Mars 1973, 1975, and 1977 opportunities
Parametric design of interplanetary and orbital trajectories with examples for Mars 1973, 1975, and 1977 opportunities
Hampshire, W. F., II↗
A theory of supercritical wing sections, with computer programs and examples.
Mathematical methods for the design of supercritical wings, which depend on the numerical solution of the partial differential equations of two-dimensional gas dynamics, are developed. The main contribution is a computer program for the design of shockless transonic airfoils using the hodograph transformation and analytic continuation into the complex domain. The mathematical theory is described, and a manual for users of the programs is provided. Numerical examples are given and computational results are discussed, and the computer programs themselves are listed. The analysis routine can be used to ascertain whether the profiles behave well at off-design conditions, or to smooth coordinates and obtain a desirable shape more quickly when perfectly shockless flow is not essential.
Bauer, F.↗
Model reference adaptive systems some examples.
A direct design method is derived for several single-input single-output model reference adaptive systems (M.R.A.S.). The approach used helps to clarify the various steps involved in a design, which utilizes the hyperstability concept. An example of a multiinput, multioutput M.R.A.S. is also discussed. Attention is given to the problem of a series compensator. It is pointed out that a series compensator which contains derivative terms must generally be introduced in the adaptation mechanism in order to assure asymptotic hyperstability. Results obtained by the simulation of a M.R.A.S. on an analog computer are also presented.
Landau, I. D.↗
Some practical examples of cavitation erosion and their prevention
The problem of failures caused by cavitation erosion are discussed. The concepts of intensity of erosion, erosion strength, and the time dependence of erosion rate are analyzed. The relation of these parameters to system variables such as pressure and velocity, and to the properties of materials are investigated. Using several examples of actual cavitation erosion, methods of prevention and their limitations are examined.
Conn, A. F.↗
A discussion of interplanetary postshock flows with two examples
Plasma and magnetometer observations of two types of flare-associated shock flows are described and compared with present models. One type represents a class of flows in which the shock is followed by a stream and separated from it by a region in which density, temperature, and speed decrease monotonically. Neither the blast wave model nor the two-stage model, in which the stream and the shock are attributed to the same flare, can quantitatively describe this class. The other type is characterized by a complex region between the shock and the following stream, which has many discontinuities and fluctuations but in which there is no increase in helium concentration. This class of event is not describable in terms of the conventional pictures presented, for example, by Hundhausen (1972). These two types of flow can be distinguished by using ground magnetograms, since the first type shows no sudden impulses following the shock, whereas the second type shows many.
Ogilvie, K. W.↗
Three examples of applied remote sensing of vegetation
Cause studies in which remote sensing techniques were adapted to assist in the solution of particular problem situations in Texas involving vegetation are described. In each case, the final sensing technique developed for operational use by the concerned organizations employed photographic sensors which were optimized through studies of the spectral reflectance characteristics of the vegetation species and background conditions unique to the problem being considered. The three examples described are: (1) Assisting Aquatic Plant Monitoring and Control; (2) Improving Vegetation Utilization in Urban Planning; and (3) Enforcing the Quarantine of Diseased Crops.
Rouse, J. W., Jr.↗
Examples of plasma flows within the earth's magnetosphere
Examples of observed plasma flows in the dayside magnetosphere near the magnetopause, within the ring current in the local evening sector, and at two positions simultaneously in the plasma sheet are presented. These measurements were gained with plasma instruments on the IMP 6 and 7 satellites. Flow velocities inside the magnetopause in the dayside magnetosphere are typically 25 to 75 km/s and are directed generally parallel to the tangent to the nearby magnetopause with a small component directed into this boundary. Bulk flow speeds within the ring current ranged from the instrument threshold of about 20 km/s to speeds of 50 km/s. Strong tailward 'jetting' of plasma, in the range of 200 to 300 km/s, at geocentric radial distances of about 35 earth radii in the plasma sheet is found to be often associated with the occurrence of magnetic substorms.
Frank, L. A.↗
The linear quadratic optimal control problem for infinite dimensional systems over an infinite horizon - Survey and examples
Available published results are surveyed for a special class of infinite-dimensional control systems whose evolution is characterized by a semigroup of operators of class C subscript zero. Emphasis is placed on an approach that clarifies the system-theoretic relationship among controllability, stabilizability, stability, and the existence of a solution to an associated operator equation of the Riccati type. Formulation of the optimal control problem is reviewed along with the asymptotic behavior of solutions to a general system of equations and several theorems concerning L2 stability. Examples are briefly discussed which involve second-order parabolic systems, first-order hyperbolic systems, and distributed boundary control.
Bensoussan, A.↗
Selected examples of dispersal of arthropods associated with agricultural crop and animal production
The economic importance of arthropods in agricultural production systems and the possibilities of using dispersal behavior to develop and manipulate control are examined. Examples of long and short distance dispersal of economic insect pests and beneficial species from cool season host reservoirs and overwintering sites are presented. Significant dispersal of these species often occurring during crop and animal production is discussed.
Henneberry, T. J.↗
Experimental and theoretical examples of the value and limitations of transition state theory
Value and limitations of transition-state theory (TST) are reviewed. TST analyses of the temperature dependence of the 'direct' reactions CH3 + CH3CHO yields CH4 + CH3CO(1) and O + CH4 yields OH + CH3(2) are presented in detail, and other examples of TST usefulness are recalled. Limitations are discussed for bimolecular processes in terms of 'complex' vs. 'direct' mechanisms. The reaction OH + CO yields CO2 + H is discussed in this context. Limitations for unimolecular processes seem to arise only for simple bond fission processes, and recent advances are noted.
Golden, D. M.↗
Examples of realistic aerosol particles collected in a cascade impactor
In this paper some scanning electron microscope photomicrographs showing examples of a variety of particulate aerosol shapes are presented. Compositions of particles also are presented. These particles represent samples from a number of different sources and locations including: solid propellant rocket motor plumes, active volcano plumes, the lower stratosphere over Sondrestrom, Greenland, and the upper troposphere over northern Texas. The particles were collected from aboard an aircraft with a cascade impactor which classified them according to aerodynamic size into 10 size intervals ranging from submicron to greater than 25 micrometers in diameter. The cascade impactor also served to measure the mass concentration as a function of particle size. The variety of shapes and compositions found among these particles suggest difficulties in obtaining reliable size distribution data from light scattering measurements.
Woods, D. C.↗
FETSIM user's manual and example
A batch program written in FORTRAN IV which does D.C. and transient analysis of MOS circuits is presented. Circuits employing N-MOS transistors and/or P-MOS transistors in either a bulk technology or an SOS technology, or almost any combination of R-C elements may be analyzed. The program requires as input data the complete circuit topology, device parameters, process parameters, and control parameters. The user can specify initial node conditions and the input pulse format. For example, pulse rise time, fall time, width and time between succeeding pulses are all independently controllable. The program contains a sophisticated mathematical model that can accurately handle either NMOS, P-MOS, Bulk or SOS devices. Sensitivity to process changes is maintained by requiring such process parameters as threshold voltage and doping level as program inputs.
Source record↗
The flux ejection dynamo with small diffusivity. I - Basic properties. II - Illustrative examples
In the first part of this paper, the flux ejection dynamo in an infinitely broad convective layer of finite depth is treated in the limit of electrical conductivity, where the convective layer upper surface is open to empty space while the lower surface is closed to the passage of fluid and field. The idealized convective overturning used allows an exact description of the symmetry and distribution of the magnetic field carried with the fluid. The total flux of the mean horizontal field grows linearly with the number of convective cycles. A discussion is given of the boundary conditions to be applied to an astronomical body whose flux ejection dynamo operates at its surface. In the second part, examples are presented which illustrate the consequences of reverse flux ejection from the surface of a convective layer of conducting fluid. Reverse flux ejection generally has the opposite effect of magnetic buoyancy, burying the fields rather than bringing them through the surface. Reverse flux injection at the surface of an alpha-omega dynamo profoundly alters the character of the solutions of dynamo equations.
Parker, E. N.↗
The computation of Laplacian smoothing splines with examples
Laplacian smoothing splines (LSS) are presented as generalizations of graduation, cubic and thin plate splines. The method of generalized cross validation (GCV) to choose the smoothing parameter is described. The GCV is used in the algorithm for the computation of LSS's. An outline of a computer program which implements this algorithm is presented along with a description of the use of the program. Examples in one, two and three dimensions demonstrate how to obtain estimates of function values with confidence intervals and estimates of first and second derivatives. Probability plots are used as a diagnostic tool to check for model inadequacy.
Wendelberger, J. G.↗
Some examples of the utility of HCMM data in geologic remote sensing
Examples of HCMM (Heat Capacity Mapping Mission) data in geologic remote sensing are presented, and the data set is composed of HCMM and aircraft digital scanner data and ground truth data from four western U.S. test sites. Data are used in the thermal model to test thermal data effectiveness, and changes in temperature with depth and time for dry soils are described by the model. It is found that the HCMM thermal inertia image is useful in the separability of bedrock and alluvium in Death Valley, and aa and pahoehoe flows in the Pisgah basalt flow. In a color composite of HCMM day temperature, night temperature, and day visible images of the Pisgah Crater test site, it is possible to distinguish alluvium, playa, aa and pahoehoe basalt flow, rhyolite intrusives, and other elements. Ground checking of units at a few points will extend capabilities to large areas and assist in creating telegeologic maps.
Kahle, A. B.↗
Water resources by orbital remote sensing: Examples of applications
Selected applications of orbital remote sensing to water resources undertaken by INPE are described. General specifications of Earth application satellites and technical characteristics of LANDSAT 1, 2, 3, and 4 subsystems are described. Spatial, temporal and spectral image attributes of water as well as methods of image analysis for applications to water resources are discussed. Selected examples are referred to flood monitoring, analysis of water suspended sediments, spatial distribution of pollutants, inventory of surface water bodies and mapping of alluvial aquifers.
Martini, P. R.↗
Lunar Mascon Loading: an Example of the Importance of Fault Initiation Depth on Fault Type Predictions from Stresses on Planetary Surfaces
Geophysical models that predict fault type from stresses calculated at the planetary surface (zero depth) can be misleading because faults generally initiate at depth under a different stress regime and propagate to the surface. The generally accepted and most commonly employed criteria for fault prediction from calculated stresses on planetary surfaces points out problems in neglecting the effects of non-isotropic overburden stresses and the use of realistic material constants and shows a well known example (mascon loading on the moon) where neglecting this effect predicts a different type of fault than is actually observed.
Golombek, M. P.↗