116
116

Jul 6, 2010
07/10

by
GORODETSKIY, A. K.; MATVEYEV, D. T.; ORLOV, A. P

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THERMAL EMISSION FROM THE SEA SURFACE AND ATMOSPHERE WERE STUDIED IN THE INFRARED AND MICROWAVE REGIONS BY SEMIAUTOMATIC CAMERAS AND PHOTOMETER ABOARD SHIP IN THE NORTH ATLANTIC. THE ROLE OF SEA FOAM IN AFFECTING MICROWAVE EMISSION WAS ALSO EXAMINED.

Topics: FUNCTION SPACE, OPERATORS (MATHEMATICS), THEOREMS, VECTORS (MATHEMATICS), DIFFERENTIAL EQUATIONS,...

186
186

May 23, 2011
05/11

by
Pinelli, Thomas E.; Barclay, Rebecca O.; Kennedy, John M

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The U.S. government technical report is a primary means by which the results of federally funded research and development (R&D) are transferred to the U.S. aerospace industry. However, little is known about this information product in terms of its actual use, importance, and value in the transfer of federally funded R&D. To help establish a body of knowledge, the U.S. government technical report is being investigated as part of the NASA/DOD Aerospace Knowledge Diffusion Research...

Topics: POLYNOMIALS, DISTANCE, ERROR CORRECTING CODES, MATRICES (MATHEMATICS), THEOREMS, FUNCTION SPACE

313
313

Jun 13, 2011
06/11

by
Malekpour, Mahyar R.; Siminiceanu, Rad

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Embedded distributed systems have become an integral part of many safety-critical applications. There have been many attempts to solve the self-stabilization problem of clocks across a distributed system. An analysis of one such protocol called the Byzantine Self-Stabilizing Pulse Synchronization (BSS-Pulse-Synch) protocol from a paper entitled ''Linear Time Byzantine Self-Stabilizing Clock Synchronization'' by Daliot, et al., is presented in this report. This report also includes a discussion...

Topics: ENVIRONMENT MANAGEMENT, FUNCTION SPACE, INFORMATION SYSTEMS, MEASURE AND INTEGRATION, DATA...

Let R be the real numbers, R(n) the linear space of all real n-tuples, and R(infinity) the linear space of all infinite real sequences x = (x sub 1, x sub 2,...). Let P sub n :R(infinity) approaches R(n) be the projection operator with P sub n (x) = (x sub 1,...,x sub n). Let p(infinity) be a probability measure on the smallest sigma-ring of subsets of R(infinity) which includes all of the cylinder sets P sub n(-1) (B sub n), where B sub n is an arbitrary Borel subset of R(n). Let p sub n be...

Topics: NASA Technical Reports Server (NTRS), FUNCTION SPACE, GEOPHYSICS, PROBABILITY THEORY, STOCHASTIC...

Genetic programming refers to a class of genetic algorithms utilizing generic representation in the form of program trees. For a particular application, one needs to provide the set of functions, whose compositions determine the space of program structures being evolved, and the set of terminals, which determine the space of specific instances of those programs. The algorithm searches the space for the best program for a given problem, applying evolutionary mechanisms borrowed from nature....

Topics: NASA Technical Reports Server (NTRS), GENETIC ALGORITHMS, COMPUTER PROGRAMMING, MEMORY (COMPUTERS),...

149
149

Sep 20, 2010
09/10

by
Gregory, John C

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Following the discovery of the atmospheric cosmogenic radionuclide Be-7 on the Long Duration Exposure Facility (LDEF), we began a search for other known nuclides produced by similar mechanisms. None of the others have the narrow gamma-ray line emission of Be-7 decay which enable its rapid detection and quantification. A search for Be-10 atoms on LDEF clamp plates using accelerator mass spectrometry is described. An unexpected result was obtained.

Topics: EXPERT SYSTEMS, PAYLOAD INTEGRATION, ROBOTICS, ROBOTS, SPACE STATION FREEDOM, ECONOMICS, FUNCTION...

By generalizing the Liapunov-Yoshizawa techniques, necessary and sufficient conditions are given for uniform boundedness and uniform ultimate boundedness of a rather general class of nonlinear differential equations of neutral type. Among the applications treated by the methods are the Lienard equation of neutral type and hereditary systems of Lurie type. The absolute stability of this later equation is also investigated. A certain existence result of a solution of a neutral functional...

Topics: NASA Technical Reports Server (NTRS), BOUNDARY VALUE PROBLEMS, CONTROLLABILITY, FUNCTION SPACE,...

Our comparisons of the single particle scattering behavior of terrestrial snows and icy satellite regoliths to the laboratory particle scattering measurements of McGuire and Hapke demonstrate that the differences between icy satellite regoliths and their terrestrial counterparts are due to particle structures and textures. Terrestrial snow particle structures define a region in the single particle scattering function parameter space separate from the regions defined by the McGuire and Hapke...

Topics: NASA Technical Reports Server (NTRS), SNOW, SCATTERING FUNCTIONS, ICY SATELLITES, REGOLITH,...

Described here is the progress made by Levels 1, 2, and 3 of the Space Station Freedom in developing and applying advanced automation and robotics technology. Emphasis was placed on the Space Station Freedom program responses to specific recommendations made in the Advanced Technology Advisory Committee (ATAC) Progress Report 13, and issues of A&R implementation into the payload operations integration Center at Marshall Space Flight Center. Assessments are presented for these and other...

Topics: NASA Technical Reports Server (NTRS), EXPERT SYSTEMS, PAYLOAD INTEGRATION, ROBOTICS, ROBOTS, SPACE...

Optimal control of systems governed by functional differential equations of retarded and neutral type is considered. Problems with function space initial and terminal manifolds are investigated. Existence of optimal controls, regularity, and bang-bang properties are discussed. Necessary and sufficient conditions are derived, and several solved examples which illustrate the theory are presented.

Topics: NASA Technical Reports Server (NTRS), DIFFERENTIAL EQUATIONS, FUNCTIONAL ANALYSIS, MANIFOLDS...

Wavelets are new mathematical objects which act as 'designer trigonometric functions.' To obtain a wavelet, the original function space of finite energy signals is generalized to a phase-space, and the translation operator in the original space has a scale change in the new variable adjoined to the translation. Localization properties in the phase-space can be improved and unconditional bases are obtained for a broad class of function and distribution spaces. Operators in phase space are...

Topics: NASA Technical Reports Server (NTRS), QUANTUM MECHANICS, QUANTUM OPTICS, QUANTUM THEORY, SQUEEZED...

The results are presented of a study to determine the performance of genetic direct search algorithms in solving function optimization problems arising in the optimal and adaptive control areas. The findings indicate that: (1) genetic algorithms can outperform standard algorithms in multimodal and/or noisy optimization situations, but suffer from lack of gradient exploitation facilities when gradient information can be utilized to guide the search. (2) For large populations, or low dimensional...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, FUNCTION SPACE, SEARCH PROFILES, ADAPTIVE...

NASA started the Ecological Program 14 years ago to collect environmental data which can be used in making environmental management decisions. The EP team created the Mapping Analysis and Planning System (MAPS) to store all the data, including the appropriate tools for data analysis and exploration.

Topics: NASA Technical Reports Server (NTRS), ENVIRONMENT MANAGEMENT, FUNCTION SPACE, INFORMATION SYSTEMS,...

299
299

May 22, 2011
05/11

by
Benjamin, Theodore G.; Garcia, Roberto; Mcconnaughey, Paul K.; Wang, Ten-See; Vu, Bruce T.; Dakhoul, Yousse

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These analyses were undertaken to aid in the understanding of flow phenomena in the Alternate Turbopump Development (ATD) High-pressure Oxidizer Turbopump (HPOTP) Pump-end ball bearing (PEBB) cavities and their roles in turbopump vibration initiation and bearing distress. This effort was being performed to provide timely support to the program in a decision as to whether or not the program should be continued. In the first case, it was determined that a change in bearing through flow had no...

Topics: ANNIHILATION REACTIONS, QUANTUM OPTICS, VECTORS (MATHEMATICS), WAVE FUNCTIONS, COHERENCE,...

Genetic algorithm (GA) inspired by Darwin's theory of evolution and employed to solve optimization problems - unconstrained or constrained - uses an evolutionary process. A GA has several parameters such the population size, search space, crossover and mutation probabilities, and fitness criterion. These parameters are not universally known/determined a priori for all problems. Depending on the problem at hand, these parameters need to be decided such that the resulting GA performs the best. We...

Topics: NASA Technical Reports Server (NTRS), GENETIC ALGORITHMS, PROBABILITY THEORY, FUNCTION SPACE,...

Domain decomposition is an intuitive organizing principle for a partial differential equation (PDE) computation, both physically and architecturally. However, its significance extends beyond the readily apparent issues of geometry and discretization, on one hand, and of modular software and distributed hardware, on the other. Engineering and computer science aspects are bridged by an old but recently enriched mathematical theory that offers the subject not only unity, but also tools for...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, COMPUTATIONAL FLUID DYNAMICS, DECOMPOSITION,...

The United States Laboratory Module "Destiny" was the product of many architectural, technology, manufacturing, schedule and cost constraints which spanned 15 years. Requirements for the Space Station pressurized elements were developed and baselined in the mid to late '80's. Although the station program went through several design changes the fundamental requirements that drove the architecture did not change. Manufacturing of the U.S. Laboratory began in the early 90's. Final...

Topics: NASA Technical Reports Server (NTRS), DESTINY LABORATORY MODULE, MEASURE AND INTEGRATION, SPACE...

The recent development of more sophisticated remote sensing systems enables the measurement of radiation in many more spectral intervals than previously possible. An example of that technology is the AVIRIS system, which collects image data in 220 bands. As a result of this, new algorithms must be developed in order to analyze the more complex data effectively. Data in a high dimensional space presents a substantial challenge, since intuitive concepts valid in a 2-3 dimensional space to not...

Topics: NASA Technical Reports Server (NTRS), REMOTE SENSING, TECHNOLOGY UTILIZATION, PROJECTION, OPTICAL...

In this work, we present an alternate set of basis functions, each defined over a pair of planar triangular patches, for the method of moments solution of electromagnetic scattering and radiation problems associated with arbitrarily-shaped, closed, conducting surfaces. The present basis functions are point-wise orthogonal to the pulse basis functions previously defined. The prime motivation to develop the present set of basis functions is to utilize them for the electromagnetic solution of...

Topics: NASA Technical Reports Server (NTRS), DIELECTRICS, ELECTROMAGNETIC SCATTERING, RADIATION, NUMERICAL...

A theory for representing a parameter-dependent function as a function trajectory is described. Additionally, a theory for determining a piecewise analytic fit to the trajectory is described. An example is given that illustrates the application of the theory to generating a smooth surface through a discrete set of input cross-section shapes. A simple procedure for smoothing in the parameter direction is discussed, and a computed example is given. Application of the theory to aerodynamic surface...

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL GRIDS, CURVE FITTING, FUNCTION SPACE, GRID...

Traditional design approaches for composite materials have employed deterministic criteria for failure analysis. New approaches are required to predict the reliability of composite structures since strengths and stresses may be random variables. This report will examine and compare methods used to evaluate the reliability of composite laminae. The two types of methods that will be evaluated are fast probability integration (FPI) methods and Monte Carlo methods. In these methods, reliability is...

Topics: NASA Technical Reports Server (NTRS), COMPOSITE STRUCTURES, FAILURE ANALYSIS, FIBER COMPOSITES,...

In this work, we present a new set of basis functions, de ned over a pair of planar triangular patches, for the solution of electromagnetic scattering and radiation problems associated with arbitrarily-shaped surfaces using the method of moments solution procedure. The basis functions are constant over the function subdomain and resemble pulse functions for one and two dimensional problems. Further, another set of basis functions, point-wise orthogonal to the first set, is also de ned over the...

Topics: NASA Technical Reports Server (NTRS), ELECTROMAGNETIC SCATTERING, METHOD OF MOMENTS, THREE...

Approximation techniques for estimating spatially varying coefficients and unknown boundary parameters in second order hyperbolic systems are discussed. Methods for state approximation (cubic splines, tau-Legendre) and approximation of function space parameters (interpolatory splines) are outlined and numerical findings for use of the resulting schemes in model "one dimensional seismic inversion' problems are summarized.

Topics: NASA Technical Reports Server (NTRS), APPROXIMATION, COMPUTATION, ESTIMATING, HYPERBOLIC...

We hypothesize that changes in otolith-mediated reflexes adapted for microgravity contribute to perceptual, gaze and postural disturbances upon return to Earth s gravity. Our goal was to determine pre- versus post-fight differences in unilateral otolith reflexes that reflect these adaptive changes. This study represents the first comprehensive examination of unilateral otolith function following space flight. Ten astronauts participated in unilateral otolith function tests three times...

Topics: NASA Technical Reports Server (NTRS), OTOLITH ORGANS, MICROGRAVITY, ASTRONAUTS, CENTRAL NERVOUS...

In this work, we present a new set of basis functions, defined over a pair of planar triangular patches, for the solution of electromagnetic scattering and radiation problems associated with arbitrarily-shaped surfaces using the method of moments solution procedure. The basis functions are constant over the function subdomain and resemble pulse functions for one and two dimensional problems. Further, another set of basis functions, point-wise orthogonal to the first set, is also defined over...

Topics: NASA Technical Reports Server (NTRS), NUMERICAL ANALYSIS, METHOD OF MOMENTS, ELECTROMAGNETIC...

From the bitsavers.org collection, a scanned-in computer-related document. mit :: ai :: aim :: AIM-736

Topics: channel, path, configuration, homotopy, paths, construction, faces, equivalence, workspace, convex,...

On or about November 10, 1988 an open circuit solder joint was discovered in the Magellan Radar digital unit (DFU) during integration testing at Kennedy Space Center (KSC). A detailed analysis of the cause of the failure was conducted at the Jet Propulsion Laboratory leading to the successful repair of many pieces of affected electronic hardware on both the Magellan and Galileo spacecraft. The problem was caused by the presence of high thermal coefficient of expansion heat sink and conformal...

Topics: NASA Technical Reports Server (NTRS), CIRCUIT BOARDS, FAILURE ANALYSIS, SOLDERED JOINTS, SPACECRAFT...

The Levenberg-Marquardt algorithm [1, 2] provides a numerical iterative solution to the problem of minimization of a function over a space of its parameters. In our work, the Levenberg-Marquardt algorithm retrieves optical parameters of a thin (single scattering) plane parallel atmosphere irradiated by collimated infinitely wide monochromatic beam of light. Black ground surface is assumed. Computational accuracy, sensitivity to the initial guess and the presence of noise in the signal, and...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, ITERATIVE SOLUTION, POLARIZATION, NUMERICAL...

A new way of diagonalizing the Jaynes-Cummings Hamiltonian is proposed, which allows the definition of annihilation operators and coherent states for this model. Mean values and dispersions over these states are computed and interpreted.

Topics: NASA Technical Reports Server (NTRS), ANNIHILATION REACTIONS, COHERENCE, HAMILTONIAN FUNCTIONS,...

Space Station Freedom is being developed to support extensive missions involving microgravity research and applications. Requirements for on-orbit payload integration and the simultaneous payload integration of multiple mission increments will provide the stimulus to develop new streamlined integration procedures in order to take advantage of the increased capabilities offered by Freedom. The United States Laboratory and its user accommodations are described. The process of integrating users'...

Topics: NASA Technical Reports Server (NTRS), LOGISTICS, PAYLOAD INTEGRATION, SPACE LABORATORIES, SPACE...

The natural space environment is characterized by many complex and subtle phenomena hostile to spacecraft. The effects of these phenomena impact spacecraft design, development, and operations. Space systems become increasingly susceptible to the space environment as use of composite materials and smaller, faster electronics increases. This trend makes an understanding of the natural space environment essential to accomplish overall mission objectives, especially in the current climate of...

Topics: NASA Technical Reports Server (NTRS), METEOROIDS, SPACE DEBRIS, SPACECRAFT DESIGN, NASA PROGRAMS,...

Two numerical methods are presented which describe the unsteady flow field in the blade-to-blade plane of an axial fan rotor. These methods solve the compressible, time-dependent, Euler and the compressible, turbulent, time-dependent, Navier-Stokes conservation equations for mass, momentum, and energy. The Navier-Stokes equations are written in Favre-averaged form and are closed with an approximate two-equation turbulence model with low Reynolds number and compressibility effects included. The...

Topics: NASA Technical Reports Server (NTRS), COMPUTERIZED SIMULATION, FLOW DISTRIBUTION, NAVIER-STOKES...

Blood pressure and mesenteric resistance artery function were assessed in 9-week-old spontaneously hypertensive rats following an 18 day shuttle flight on STS-80. Blood pressure was measured twice, first in conscious animals using a tail-cuff method and then while the animals were anesthetized with 2% halothane in O2. Isolated mesenteric resistance artery responses to cumulative additions of norepinephrine, acetylcholine, sodium nitroprusside, and calcium were measured within 17 hours of...

Topics: NASA Technical Reports Server (NTRS), MICROGRAVITY, NITRIC OXIDE, ENDOTHELIUM, BLOOD PRESSURE,...