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Jun 21, 2010
06/10

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Conference on mechanical engineering aspects of satellite systems - dynamic structural analyses and developments of control mechanisms, design specifications, and equipment components

Topics: ALGORITHMS, COMPUTER PROGRAMMING, FLOW CHARTS, SEQUENTIAL COMPUTERS, INPUT, MECHANIZATION, SHIFT...

489
489

May 31, 2011
05/11

by
Leventis, Nicholas; Zhang, Guo-Hui; Rawashdeh, Abdel-Monem M.; Sotiriou-Leventis, Charikli

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In analogy to 4-(para-substituted benzoyl)-N-methylpyridinium cations (1-X's), the title species (2-X's, -X = -OCH3, -CH3, -H, -Br, -COCH3, -NO2) undergo two reversible, well-separated (E(sub 1/2) greater than or equal to 650 mV) one-electron reductions. The effect of substitution on the reduction potentials of 2-X's is much weaker than the effect of the same substituents on 1-X's: the Hammett rho-values are 0.80 and 0.93 for the 1st- and 2nd-e reduction of 2-X's vs. 2.3 and 3.3 for the same...

Topics: ARCHITECTURE (COMPUTERS), PARALLEL COMPUTERS, INTERFACES, RELIABILITY ANALYSIS, COMPUTER...

490
490

May 6, 2010
05/10

by
Clem, T. D.; Schaffert, J. C

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Solid state satellite separation sequence timer to provide for payload separation sequence at approximate intervals

Topics: PAYLOADS, SATELLITES, SEQUENTIAL COMPUTERS, SOLID STATE, SOLID STATE DEVICES, TIMING DEVICES,...

A tabulation is given of long systematic and long quick-look-in (QLI) nonsystematic rate R = 1/2 binary convolutional codes with an optimum distance profile (ODP). These codes appear attractive for use with sequential decoders. Simulations for two of the new codes are reported and confirm Massey's conjecture that systematic and non-systematic codes of the same rate yield nearly identical computational and error probability performance with sequential decoding when the number of digits...

Topics: NASA Technical Reports Server (NTRS), BINARY CODES, DECODERS, SEQUENTIAL COMPUTERS, PROBABILITY...

The computations are reordered in the SOR algorithm to maintain the same asymptotic rate of convergence as the rowwise ordering to obtain parallelism at different levels. A parallel program is written to illustrate these ideas and actual machines for implementation of this program are discussed.

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, COMPUTATION, CONVERGENCE, PARALLEL PROGRAMMING,...

249
249

Jun 21, 2010
06/10

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NON

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Cross correlation of reverse maximal length shift register sequences

Topics: DECODING, OSCILLATORS, PROBABILITY THEORY, PERFORMANCE PREDICTION, PIONEER SPACE PROBES, SEQUENTIAL...

Report discusses several methods of performing numerical integration with computer. When data can be expressed as state vector that is dependent variable in a differential equation, self-starting integrators can be used to predict future data.

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

A new parallel Jacobi-like algorithm is developed for computing the eigenvalues of a general complex matrix. Most parallel methods for this parallel typically display only linear convergence. Sequential norm-reducing algorithms also exit and they display quadratic convergence in most cases. The new algorithm is a parallel form of the norm-reducing algorithm due to Eberlein. It is proven that the asymptotic convergence rate of this algorithm is quadratic. Numerical experiments are presented...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, CONVERGENCE, EIGENVALUES, EIGENVECTORS, PARALLEL...

This manual presents a computer program that performs all the work required for the logic design of digital counters or sequential circuits and the simplification of Boolean logic expressions. The program provides both the experienced and inexperienced logic designer with a comprehensive logic design capability. The manual contains Boolean simplification and sequential design theory, detailed instructions for use of the program, a large number of illustrative design examples, and complete...

Topics: NASA Technical Reports Server (NTRS), COMPUTER PROGRAMS, DIGITAL SYSTEMS, LOGIC CIRCUITS, LOGIC...

A set of code sequences is a complementary code sequence set if the sum of the aperiodic autocorrelation functions for the sequences is zero everywhere except at the origin. A simple construction for sets of complementary code sequences is discussed.

Topics: NASA Technical Reports Server (NTRS), BITERNARY CODE, CODING, SEQUENCING, SEQUENTIAL COMPUTERS, SET...

The parallel and pipeline organization of fast unitary transform algorithms such as the Fast Fourier Transform are discussed. The efficiency is pointed out of a combined parallel-pipeline processor of a transform such as the Haar transform in which 2 to the n minus 1 power hardware butterflies generate a transform of order 2 to the n power every computation cycle.

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, FAST FOURIER TRANSFORMATIONS, COMPUTER...

When porting sequential applications to parallel computer architectures, the program developer will typically go through several cycles of source code optimization and performance analysis. We have started a project to develop an environment where the user can jointly navigate through program structure and performance data information in order to make efficient optimization decisions. In a prototype implementation we have interfaced the CAPO computer aided parallelization tool with the Paraver...

Topics: NASA Technical Reports Server (NTRS), ARCHITECTURE (COMPUTERS), PARALLEL COMPUTERS, INTERFACES,...

The theory and techniques applicable to the on-line diagnosis of sequential systems, were investigated. A complete model for the study of on-line diagnosis is developed. First an appropriate class of system models is formulated which can serve as a basis for a theoretical study of on-line diagnosis. Then notions of realization, fault, fault-tolerance and diagnosability are formalized which have meaningful interpretations in the the context of on-line diagnosis. The diagnosis of systems which...

Topics: NASA Technical Reports Server (NTRS), FAILURE ANALYSIS, ON-LINE PROGRAMMING, SEQUENTIAL COMPUTERS,...

A method and apparatus is presented for reformatting and de-serializing a serially-received sequence of data words, each consisting of a fixed number of binary data bits. A block of nm bits is serially fed into a shift register or serially-connected group of shift registers. In lieu of the(nm-1)th shifts, the bits are rearranged within the shift register in parallel fashion, according to a prescribed scheme. Shifting then continues, until the first bit of each data word appears in the last bit...

Topics: NASA Technical Reports Server (NTRS), DIGITAL DATA, FORMAT, PARALLEL PROCESSING (COMPUTERS),...

Formal procedures for synthesis of asynchronous sequential system using commercially available edge-sensitive flip-flops are developed. Boolean differential is defined. The exact number of compatible integrals of a Boolean differential were calculated.

Topics: NASA Technical Reports Server (NTRS), BOOLEAN FUNCTIONS, NUMERICAL INTEGRATION, SEQUENTIAL...

Computational procedures for kinematic and dynamic analysis of three-dimensional multibody dynamic (MBD) systems are developed from the differential-algebraic equations (DAE's) viewpoint. Constraint violations during the time integration process are minimized and penalty constraint stabilization techniques and partitioning schemes are developed. The governing equations of motion, a two-stage staggered explicit-implicit numerical algorithm, are treated which takes advantage of a partitioned...

Topics: NASA Technical Reports Server (NTRS), ALGORITHMS, BODY KINEMATICS, DYNAMIC STRUCTURAL ANALYSIS,...

The development of vector processing computers of the streaming array architectures has made possible a dramatic decrease in the time required for the solution of problems, i.e., for those algorithms which readily lend themselves to sequential operations on long vectors. There has concurrently been rapid growth in the applications of the techniques generally known as mathematical digital filtering, also called signal analysis, digital signal processing, time series analysis, and digital image...

Topics: NASA Technical Reports Server (NTRS), COMPUTER TECHNIQUES, CONVOLUTION INTEGRALS, DIGITAL SYSTEMS,...

This final report for research that was supported by grant number NAG-1-995 documents our progress in addressing two difficulties in parallel programming. The first difficulty is developing software that will execute quickly on a parallel computer. The second difficulty is transporting software between dissimilar parallel computers. In general, we expect that more hardware-specific information will be included in software designs for parallel computers than in designs for sequential computers....

Topics: NASA Technical Reports Server (NTRS), COMPUTER SYSTEMS PERFORMANCE, COMPUTER SYSTEMS PROGRAMS,...

No abstract available

Topics: NASA Technical Reports Server (NTRS), COMPUTATIONAL FLUID DYNAMICS, COMPUTERIZED SIMULATION,...

268
268

Jun 21, 2010
06/10

by
Beitel, G. A.; Gosselin, C. M

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Collector gauge and orbitron gauge for ultrahigh vacuum measurements

Topics: AUTOMATA THEORY, DIGITAL COMPUTERS, FUNCTIONAL ANALYSIS, LOGIC DESIGN, RANDOM PROCESSES, REDUNDANCY...