184
184

Jun 1, 2010
06/10

by
Stakvilevichus, M. I

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Gravitational effect on particle-like solutions

Topics: GRAVITATION, GRAVITATIONAL EFFECTS, PARTICLES, SCALARS, SOLUTION, GRAVITATIONAL EFFECT, PARTICLE,...

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249

Jun 21, 2010
06/10

by
Brockman, P.; Brooks, D. R.; Hess, R. V.; Hoell, J. M., Jr

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Diagnostics and interpretation of acceleration mechanism in magnetoplasmadynamic arc

Topics: OPTIMIZATION, SCALARS, TOPOLOGY, VECTOR ANALYSIS, CONSTRAINTS, LINEAR TRANSFORMATIONS, WEIGHTING...

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343

May 27, 2011
05/11

by
Chato David J.; Dalton, Penni J.; Dodge, Franklin T.; Green, Stev

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The Liquid Motion Experiment (LME), designed to study the effects of liquid motion in rotating tanks, was flown on STS 84. LME was essentially a spin table that created a realistic nutation motion of scale-model tanks containing liquid. TWo spherical and two cylindrical transparent tanks were tested simultaneously, and three sets of such tanks were employed to vary liquid viscosity, fill level, and propellant management device (PMD) design. All the tanks were approximately 4.5 inches diameter....

Topics: PROTONS, MAGNETOMETERS, GROUND STATIONS, BIAS, VECTORS (MATHEMATICS), SCALARS, INTERNATIONAL...

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347

Jul 26, 2010
07/10

by
Schubert, S.; Park, C.-K.; Higgins, W.; Moorthi, S.; Suarez, M

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This document is an atlas of the European Center for Medium Range Weather Forecasts (ECMWF) initialized analyses for 1980 to 1987. Various first moment quantities are presented for monthly, seasonal, and annual averages on a global cylindrical projection, as well as, cross section maps of zonal averages. Global maps of winds, temperature, stream function, and velocity potential are presented at 850 and 200 mb. In addition, global maps of the 300 mb height field (total and eddy), the 500 mb...

Topics: CONSERVATION LAWS, CONTINUUMS, ENTROPY, KINETIC EQUATIONS, SCALARS, INEQUALITIES, NONLINEAR...

Scalar multiplication is an essential operation in elliptic curve cryptosystems because its implementation determines the speed and the memory storage requirements. This paper discusses some improvements on two popular signed window algorithms for implementing scalar multiplications of an elliptic curve point - Morain-Olivos's algorithm and Koyarna-Tsuruoka's algorithm.

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, SCALARS, MULTIPLICATION, MEMORY (COMPUTERS), Vo,...

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279

May 31, 2011
05/11

by
Khaiyer, M. M.; Rapp, A. D.; Doelling, D. R.; Nordeen, M. L.; Minnis, P.; Smith, W. L., Jr.; Nguyen, L

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While the various instruments maintained at the Atmospheric Radiation Measurement (ARM) Program Southern Great Plains (SGP) Central Facility (CF) provide detailed cloud and radiation measurements for a small area, satellite cloud property retrievals provide a means of examining the large-scale properties of the surrounding region over an extended period of time. Seasonal and inter-annual climatological trends can be analyzed with such a dataset. For this purpose, monthly datasets of cloud and...

Topics: HARDWARE, HIERARCHIES, ERRORS, ALGORITHMS, TIME, VARIATIONS, DATA STRUCTURES, TRANSPARENCE,...

615
615

Aug 1, 2010
08/10

by
Joseph, Charles L.; Jenkins, Edward B

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MSLAP is a software for analyzing spectra, providing the basic structure to identify spectral features, to make quantitative measurements of this features, and to store the measurements for convenient access. MSLAP can be used to measure not only the zeroth moment (equivalent width) of a profile, but also the first and second moments. Optical depths and the corresponding column densities across the profile can be measured as well for sufficiently high resolution data. The software was developed...

Topics: CALIBRATING, SCALARS, MAGNETIC FIELDS, MAGNETOMETERS, SPACECRAFT MODELS, GEOCENTRIC COORDINATES,...

This viewgraph presentation reviews the classification of Remote Sensing data in relation to epidemiology. Classification is a way to reduce the dimensionality and precision to something a human can understand. Classification changes SCALAR data into NOMINAL data.

Topics: NASA Technical Reports Server (NTRS), CLASSIFICATIONS, EPIDEMIOLOGY, REMOTE SENSING, SCALARS,...

678
678

Sep 20, 2010
09/10

by
Sloan, Alan D

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A deterministic fractal is an image which has low information content and no inherent scale. Because of their low information content, deterministic fractals can be described with small data sets. They can be displayed at high resolution since they are not bound by an inherent scale. A remarkable consequence follows. Fractal images can be encoded at very high compression ratios. This fern, for example is encoded in less than 50 bytes and yet can be displayed at resolutions with increasing...

Topics: AMPLIFICATION, KALMAN FILTERS, LINEAR FILTERS, MIMO (CONTROL SYSTEMS), SCALARS, MATRICES...

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326

Jun 3, 2011
06/11

by
Sokol, Jeff; Krishnan, Satish; Ayari, Laouce

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The High Gain Antenna Assemblies built for the 2003-2004 Mars Exploration Rover (MER) missions provide the primary communication link for the Rovers once they arrive on Mars. The High Gain Antenna Gimbal (HGAG) portion of the assembly is a two-axis gimbal that provides the structural support, pointing, and tracking for the High Gain Antenna (HGA). The MER mission requirements provided some unique design challenges for the HGAG. This paper describes all the major subsystems of the HGAG that were...

Topics: MICROWAVE INTERFEROMETERS, FOURIER TRANSFORMATION, IMAGING TECHNIQUES, MICROWAVE IMAGERY, THEOREMS,...

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296

Jun 9, 2011
06/11

by
Monell, Donald W.; Piland, William M

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Past designs of complex aerospace systems involved an environment consisting of collocated design teams with project managers, technical discipline experts, and other experts (e.g. manufacturing and systems operations). These experts were generally qualified only on the basis of past design experience and typically had access to a limited set of integrated analysis tools. These environments provided less than desirable design fidelity, often lead to the inability of assessing critical...

Topics: UNSTRUCTURED GRIDS (MATHEMATICS), UPWIND SCHEMES (MATHEMATICS), ERROR ANALYSIS, ANISOTROPY,...

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323

May 22, 2011
05/11

by
Ruyten, Wilhelmus M.; Friedly, Verlin J.; Peng, Xiaohang; Keefer, Denni

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Experimental facilities for electric propulsion testing at the University of Tennessee Space Institute, jointly operated by the Center for Advanced Space Propulsion, include a cryogenically cooled, computer-controlled, 9 ft diameter by 20 ft long vacuum chamber, capable of maintaining a baseline pressure of 10(exp -7) Torr, a 30 cm diameter ion thruster, and laser diagnostic and electrical diagnostic instrumentation. These facilities are described here in some detail, with emphasis on the...

Topics: CODES, COMPUTER PROGRAMMING, CONVOLUTION INTEGRALS, SIGNAL ENCODING, TRELLIS CODING, VITERBI...

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239

May 23, 2011
05/11

by
Palosz, W.; Grasza, K.; Gillies, D.; Jerman, G

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Bulk crystals of cadmium-zinc telluride, 23 mm in diameter and up to 45 grams in weight were grown. Controlled seed formation procedure was used to limit the number of grains in the crystal. Most uniform distribution of ZnTe in the crystals was obtained using excess (Cd Zn) pressure in the ampoule.

Topics: EARTH CORE, GEOMAGNETISM, RANDOM PROCESSES, NORMAL DENSITY FUNCTIONS, SCALARS, CORE-MANTLE...

A method of approximating a scalar function of n independent variables (where n is a positive integer) to arbitrary accuracy has been developed. This method is expected to be attractive for use in engineering computations in which it is necessary to link global models with local ones or in which it is necessary to interpolate noiseless tabular data that have been computed from analytic functions or numerical models in n-dimensional spaces of design parameters.

Topics: NASA Technical Reports Server (NTRS), ANALYTIC FUNCTIONS, INDEPENDENT VARIABLES, SCALARS,...

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208

May 22, 2011
05/11

by
Cox, G. B., Jr.; Steele, L. L.; Eisenhart, D. W

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Following the start of SSME certification testing for the Pratt and Whitney Alternate Turbopump Development (ATD) High Pressure Oxidizer Turbopump (HPOTP), cracking of the leading edge of the inner HEX vane was experienced. The HEX vane, at the inlet of the oxidizer bowl in the Hot Gas Manifold (HGM), accepts the HPOTP turbine discharge flow and turns it toward the Gaseous Oxidizer Heat Exchanger (GOX HEX) coil. The cracking consistently initiated over a specific circumferential region of the...

Topics: CLASSICAL MECHANICS, CONSERVATION LAWS, FIELD THEORY (PHYSICS), GRAVITATIONAL FIELDS, LAGRANGIAN...

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123

May 31, 2011
05/11

by
NON

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West Coast Netting, Inc.'s net of Hyperester twine, is made of three strands of fiber twisted together by a company-invented sophisticated twisting machine and process that maintain precisely the same tension on each strand. The resulting twine offers higher strength and improved abrasion resistance. The technology that created the Hyperester supertwine has found spinoff applications, first as an extra-efficient seine for tuna fishing, then as a capture net for law enforcement agencies. The...

Topics: STUDENTS, COORDINATES, MAGNETIC PERMEABILITY, TENSOR ANALYSIS, PHYSICS, ANALYSIS (MATHEMATICS),...

A discrete finite dimensional system, nonharmonic Fourier series and controllability, reduction to canonical form, and spectral synthesis are considered. The extent to which the eigenvalue associated with a controllable pair of a certain type may be modified via continuous linear state feedback is demonstrated.

Topics: NASA Technical Reports Server (NTRS), CANONICAL FORMS, FINITE DIFFERENCE THEORY, FOURIER SERIES,...

The presentation centers on four classes of systems that can be treated as linear systems over a ring. These are: (1) discrete-time systems over a ring of scalars such as the integers; (2) continuous-time systems containing time delays; (3) large-scale discrete-time systems; and (4) time-varying discrete-time systems.

Topics: NASA Technical Reports Server (NTRS), ALGEBRA, LINEAR SYSTEMS, RINGS (MATHEMATICS), DISCRETE...

The author shows that the sum or difference of two vectors is a vector. Similarly the sum of any two tensors of the same order is a tensor of that order. No meaning is attached to the sum of tensors of different orders, say u(sub i) + u(sub ij); that is not a tensor. In general, an equation containing tensors has meaning only if all the terms in the equation are tensors of the same order, and if the same unrepeated subscripts appear in all the terms. These facts will be used in obtaining...

Topics: NASA Technical Reports Server (NTRS), COORDINATE TRANSFORMATIONS, FLUID DYNAMICS, SCALARS, TENSORS,...

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226

May 23, 2011
05/11

by
Ohman, Lynne E

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Rats with either bilateral electrolytic or sham lesions of the ventrolateral portion of the lateral parabrachial nucleus (VLLPBN) were implanted with latex balloons that lay at the right superior vena cava/atrial junction (RSVC/AJ). Water intake in response to isoproterenol was measured both with and without inflation of the balloon. Water intake of the sham-lesioned rats was significantly depressed by balloon inflation during the first hour of the experiment. In contrast, water intake in the...

Topics: TENSORS, DEGENERATION, MATRICES (MATHEMATICS), TENSOR ANALYSIS, EIGENVECTORS, SINGULARITY...

Many high-performance isosurface extraction algorithms have been proposed in the past several years as a result of intensive research efforts. When applying these algorithms to large-scale time-varying fields, the storage overhead incurred from storing the search index often becomes overwhelming. this paper proposes an algorithm for locating isosurface cells in time-varying fields. We devise a new data structure, called Temporal Hierarchical Index Tree, which utilizes the temporal coherence...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, EXTRACTION, DATA STRUCTURES, CHARGE INJECTION...

Semi-discrete generalizations of the second order extension of Godunov's scheme, known as the MUSCL scheme, are constructed, starting with any three point E scheme. They are used to approximate scalar conservation laws in one space dimension. For convex conservation laws, each member of a wide class is proven to be a convergent approximation to the correct physical solution. Comparison with another class of high resolution convergent schemes is made.

Topics: NASA Technical Reports Server (NTRS), APPROXIMATION, CONSERVATION LAWS, CONVERGENCE, ENTROPY, HIGH...

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282

May 23, 2011
05/11

by
Steenken, William G.; Williams, John G.; Yuhas, Andrew J.; Walsh, Kevin R

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The F404-GE-400-powered F/A-18A High Alpha Research Vehicle (HARV) was used to examine the quality of inlet airflow during departed flight maneuvers, that is, during flight outside the normal maneuvering envelope where control surfaces have little or no effectiveness. Six nose-left and six nose-right departures were initiated at Mach numbers between 0.3 and 0.4 at an altitude of 35 kft. The entry yaw rates were approximately 40 to 90 deg/sec. Engine surges were encountered during three of the...

Topics: SCALARS, TWO DIMENSIONAL MODELS, VISUAL OBSERVATION, THREE DIMENSIONAL MODELS, COMPUTER PROGRAMS,...

Convenient conditions for nonlinear difference schemes to be total-variation diminishing (TVD) are reviewed. It is shown that such schemes share the TVD property, provided their numerical fluxes meet a certain positivity condition at extrema values but can be arbitrary otherwise. The conditions are invariant under different incremental representations of the nonlinear schemes, and thus provide a simplified generalization of the TVD conditions due to Harten and others.

Topics: NASA Technical Reports Server (NTRS), DIFFERENCE EQUATIONS, LIPSCHITZ CONDITION, NONLINEARITY, TVD...

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343

May 22, 2011
05/11

by
Langer, William D.; Wilson, Robert W.; Anderson, Charles H

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The structure of infrared cirrus clouds is analyzed with Laplacian pyramid transforms, a form of non-orthogonal wavelets. Pyramid and wavelet transforms provide a means to decompose images into their spatial frequency components such that all spatial scales are treated in an equivalent manner. The multiscale transform analysis is applied to IRAS 100 micrometer maps of cirrus emission in the north Galactic pole region to extract features on different scales. In the maps we identify filaments,...

Topics: SCALARS, STRESS ANALYSIS, SCIENTIFIC VISUALIZATION, STREAMLINED BODIES, TENSOR ANALYSIS, TENSORS,...

Models of the main geomagnetic field are generally represented by a scalar potential gamma expanded in a finite number of spherical harmonics. Very accurate observations of F were used, but indications exist that the accuracy of models derived from them is considerably lower. One problem is that F does not always characterize gamma uniquely. It is not clear whether such ambiguity can be encountered in deriving gamma from F in geomagnetic surveys, but there exists a connection, due to the fact...

Topics: NASA Technical Reports Server (NTRS), GEOMAGNETISM, SCALARS, SPHERICAL HARMONICS, MATHEMATICAL...

Physical and transform space filtering has been applied to the Fourier spectral collocation solution of the constant coefficient scalar wave equation with a discontinuous initial condition. High order accuracy can be extracted from the unfiltered solution. Smooth, high order Fourier space filtering gives expected polynomial order solutions away from the discontinuity. Spectral accuracy is observed with the physical space filter of Gottlieb and Tadmor.

Topics: NASA Technical Reports Server (NTRS), DISCONTINUITY, HYPERBOLIC DIFFERENTIAL EQUATIONS, SPECTRAL...

Effects of roughness in boundary layers have to be addressed. Until adverse pressure gradient effects are understood, roughness will not significantly drive design. Mechanisms responsible for separation not understood. Effects on Zero Pressure Gradient boundary layers (shear stress). Effects on separation in pressure gradient (prediction of separation). Effect on scalar transport (heat transfer) not understood. Model for skin friction needed in simulations - first grid point likely to be in...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY LAYERS, SURFACE ROUGHNESS, COMPUTATIONAL GRIDS, HEAT...

Autonomous environment-monitoring networks (AEMNs) are artificial neural networks that are specialized for recognizing familiarity and, conversely, novelty. Like a biological neural network, an AEMN receives a constant stream of inputs. For purposes of computational implementation, the inputs are vector representations of the information of interest. As long as the most recent input vector is similar to the previous input vectors, no action is taken. Action is taken only when a novel vector is...

Topics: NASA Technical Reports Server (NTRS), ENVIRONMENTAL MONITORING, AUTONOMY, NEURAL NETS,...

462
462

May 23, 2011
05/11

by
Forkey, Joseph N.; Lempert, Walter R.; Miles, Richard B

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Filtered Rayleigh Scattering (FRS) is a diagnostic technique which measures velocity, temperature, and pressure by determining Doppler shift, total intensity, and spectral line shape of laser induced Rayleigh-Brillouin scattering. In the work reported here, this is accomplished by using a narrow line width, injection seeded Nd-YAG laser sheet to induce Rayleigh-Brillouin scattering from a gas flow. This light is passed through an optical notch filter, and transmitted light is imaged onto an...

Topics: DYNAMICAL SYSTEMS, EIGENVECTORS, FORMALISM, SCALARS, MULTIVARIATE STATISTICAL ANALYSIS, SCIENTIFIC...

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513

May 23, 2011
05/11

by
Knight, Doyle D

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A computational study of the crossing shock wave-turbulent boundary layer interaction is presented. The shock waves are generated by a pair of fins which are mounted normal to a flat plate and form a converging channel. The focus of the study is to investigate the ability of the theoretical turbulence model to provide for improvement in the predictions of adiabatic wall temperature and heat transfer rates during the interaction of the shock waves with the turbulent boundary layer on the flat...

Topics: HANKEL FUNCTIONS, TIME DEPENDENCE, INVARIANCE, SINGULARITY (MATHEMATICS), FLEXIBLE BODIES,...

An exact solution of the Einstein equations for a static, planar domain wall with finite thickness is presented. At infinity, density and pressure vanish and the space-time tends to the Minkowski vacuum on one side of the wall and to the Taub vacuum on the other side. A surprising feature of this solution is that the density and pressure distribution are symmetric about the central plane of the wall whereas the space-time metric and therefore also the gravitational field experienced by a test...

Topics: NASA Technical Reports Server (NTRS), DOMAIN WALL, EINSTEIN EQUATIONS, GRAVITATION THEORY,...

A method was developed for determining the stability of a scalar neutral equation with constant coefficients and constant time delays. A neutral equation is basically a differential equation in which the highest derivative appears both with and without a time delay. Time delays may appear also in the lower derivatives or the independent variable itself. The method is easily implemented, and an illustrative example is presented.

Topics: NASA Technical Reports Server (NTRS), DIFFERENTIAL EQUATIONS, STABILITY, TIME LAG, DIFFERENCE...

To grow as a space faring race, future spaceflight systems will requires new propulsion physics. Specifically a propulsion physics model that does not require mass ejection without limiting the high thrust necessary to accelerate within or beyond our solar system and return within a normal work period or lifetime. In 2004 Khoury and Weltman produced a density dependent cosmology theory they called Chameleon Cosmology, as at its nature, it is hidden within known physics. This theory represents a...

Topics: NASA Technical Reports Server (NTRS), PROPULSION, PROPELLANTS, HIGH THRUST, SPACE FLIGHT, VACUUM,...

Mathematical Solutions Toolset is a collection of five software programs that rapidly solve some common mathematical problems. The programs consist of a set of Microsoft Excel worksheets. The programs provide for entry of input data and display of output data in a user-friendly, menu-driven format, and for automatic execution once the input data has been entered.

Topics: NASA Technical Reports Server (NTRS), CARTESIAN COORDINATES, CUBIC EQUATIONS, MATRICES...

In this article, we consider the application of three popular domain decomposition methods to Lagrange-type nonconforming finite element discretizations of scalar, self-adjoint, second order elliptic equations. The additive Schwarz method of Dryja and Widlund, the vertex space method of Smith, and the balancing method of Mandel applied to nonconforming elements are shown to converge at a rate no worse than their applications to the standard conforming piecewise linear Galerkin discretization....

Topics: NASA Technical Reports Server (NTRS), DECOMPOSITION, ELLIPTIC DIFFERENTIAL EQUATIONS, FINITE...

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430

Jul 23, 2010
07/10

by
NON

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Topics addressed include: remote sensing; petrology; imaging spectroscopy; structural properties; thermal evolution; Earth mantle; early Earth; and megageomorphology.

Topics: DIFFUSION FLAMES, TURBULENCE MODELS, VORTICITY, FLAME PROPAGATION, MIXING LAYERS (FLUIDS), SCALARS,...

This paper presents a solution to the initialization problem for a system of linear fractional-order differential equations. The scalar problem is considered first, and solutions are obtained both generally and for a specific initialization. Next the vector fractional order differential equation is considered. In this case, the solution is obtained in the form of matrix F-functions. Some control implications of the vector case are discussed. The suggested method of problem solution is shown via...

Topics: NASA Technical Reports Server (NTRS), DIFFERENTIAL EQUATIONS, LINEAR EQUATIONS, EIGENVECTORS,...

407
407

May 23, 2011
05/11

by
Hinkle, C. Ross; Knott, W. M., II

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Twenty-four launches of the space shuttle have occurred since 1981. The environmental effects of those launches have been categorized into near-field short-term acute, near-field long-term chronic and far-field long-term chronic. Impacts are generated in the near-field by the deposition of 3.4 x 10(exp 3) kg of HCl and 7.1 x 10(exp 3) kg of particulates consisting of pad surface debris and Al2O3- far-field (greater than 1 km) deposition of HCl varied from 25 to 5300 mg/sq m based on leaf...

Topics: SOOT, REFRACTIVITY, SCALARS, FLOW DISTRIBUTION, RADIATIVE HEAT TRANSFER, TURBULENCE MODELS,...

We prove a cell entropy inequality for a class of high order discontinuous Galerkin finite element methods approximating conservation laws, which implies convergence for the one dimensional scalar convex case.

Topics: NASA Technical Reports Server (NTRS), CONSERVATION LAWS, ENTROPY, FINITE ELEMENT METHOD, GALERKIN...

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187

Jul 26, 2010
07/10

by
Banks, H. T.; Rebnord, D. A

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Convergence and stability results for least squares inverse problems involving systems described by analytic semigroups are presented. The practical importance of these results is demonstrated by application to several examples from problems of estimation of material parameters in flexible structures using accelerometer data.

Topics: ALGORITHMS, SCALARS, STEADY STATE, COMPUTATIONAL FLUID DYNAMICS, DIFFERENTIAL EQUATIONS, FINITE...

LeVeque and Yee recently investigated a one-dimensional scalar conservation law with stiff source terms modeling the reacting flow problems and discovered that for the very stiff case most of the current finite difference methods developed for non-reacting flows would produce wrong solutions when there is a propagating discontinuity. A numerical scheme, essentially nonoscillatory/subcell resolution - characteristic direction (ENO/SRCD), is proposed for solving conservation laws with stiff...

Topics: NASA Technical Reports Server (NTRS), CONSERVATION LAWS, FINITE DIFFERENCE THEORY, FLUID DYNAMICS,...

A nonlinear kinetic equation is constructed and proved to be well-adapted to describe general multidimensional scalar conservation laws. In particular, it is proved to be well-posed uniformly in epsilon - the microscopic scale. It is also shown that the proposed kinetic equation is equipped with a family of kinetic entropy functions - analogous to Boltzmann's microscopic H-function, such that they recover Krushkov-type entropy inequality on the macroscopic scale. Finally, it is proved by both -...

Topics: NASA Technical Reports Server (NTRS), CONSERVATION LAWS, CONTINUUMS, ENTROPY, KINETIC EQUATIONS,...

Here we present a simple stochastic mixing model based on the law of large numbers (LLN). The reason why the LLN is involved in our formulation of the mixing problem is that the random conserved scalar c = c(t,x(t)) appears to behave as a sample mean. It converges to the mean value mu, while the variance sigma(sup 2)(sub c) (t) decays approximately as t(exp -1). Since the variance of the scalar decays faster than a sample mean (typically is greater than unity), we will introduce some non-linear...

Topics: NASA Technical Reports Server (NTRS), STOCHASTIC PROCESSES, MIXING, DECAY, VARIANCE (STATISTICS),...

We start with the total energy E for a system of three scalar relativistic particles that, because of Einstein's relation, will have square roots of functions of the momenta. By taking powers of this relation, we finally get a fourth degree polynomial in E(exp 2), where the square roots have disappeared, and which we can convert into a type of Schroedinger equation. To be in the center of mass frame we pass to Jocobi momenta and then replace them by creation and annihilation operators. We thus...

Topics: NASA Technical Reports Server (NTRS), MANY BODY PROBLEM, OSCILLATORS, RELATIVISTIC PARTICLES,...

An experimental investigation was conducted for the combined purposes of determining the relative merits of various category scales for the prediction of human discomfort response to vibration and for determining the mathematical relationships whereby subjective data are transformed from one scale to other scales. There were 16 category scales analyzed representing various parametric combinations of polarity, that is, unipolar and bipolar, scale type, and number of scalar points. Results...

Topics: NASA Technical Reports Server (NTRS), COMFORT, RIDING QUALITY, VIBRATION EFFECTS, POLARITY,...

The convergence of the Fourier method for scalar nonlinear conservation laws which exhibit spontaneous shock discontinuities is discussed. Numerical tests indicate that the convergence may (and in fact in some cases must) fail, with or without post-processing of the numerical solution. Instead, a new kind of spectrally accurate vanishing viscosity is introduced to augment the Fourier approximation of such nonlinear conservation laws. Using compensated compactness arguments, it is shown that...

Topics: NASA Technical Reports Server (NTRS), CONSERVATION LAWS, CONVERGENCE, NONLINEAR SYSTEMS, SPECTRAL...

The stability characteristics of various compact fourth and sixth order spatial operators are assessed using the theory of Gustafsson, Kreiss and Sundstrom (G-K-S) for the semi-discrete Initial Boundary Value Problem (IBVP). These results are then generalized to the fully discrete case using a recently developed theory of Kreiss. In all cases, favorable comparisons are obtained between the G-K-S theory, eigenvalue determination, and numerical simulation. The conventional definition of stability...

Topics: NASA Technical Reports Server (NTRS), BOUNDARIES, BOUNDARY VALUE PROBLEMS, FINITE DIFFERENCE...

The diffraction of an electromagnetic wave by a perfectly-conducting right-angled wedge with one surface covered by a dielectric slab or absorber is considered. The effect of the coated surface is approximated by a uniform surface impedance. The solution of the normally incident electromagnetic problem is facilitated by introducing two scalar fields which satisfy a mixed boundary condition on one surface of the wedge and a Neumann of Dirichlet boundary condition on the other. A functional...

Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC RADIATION, WAVE DIFFRACTION, WEDGES, ANTENNA...

MatLab Script and Functional Programming: MatLab is one of the most widely used very high level programming languages for scientific and engineering computations. It is very user-friendly and needs practically no formal programming knowledge. Presented here are MatLab programming aspects and not just the MatLab commands for scientists and engineers who do not have formal programming training and also have no significant time to spare for learning programming to solve their real world problems....

Topics: NASA Technical Reports Server (NTRS), PROGRAMMING LANGUAGES, COMPUTER PROGRAMMING, HIGH LEVEL...