Development and flight tests of a Kalman filter for navigation during terminal area and landing operations

A Kalman filter for aircraft terminal area and landing navigation was implemented and flight tested in the NASA Ames STOLAND avionics computer onboard a Twin Otter aircraft. This system combines navaid measurements from TACAN, MODILS, air data, radar altimeter sensors along with measurements from strap-down accelerometer and attitude angle sensors. The flight test results demonstrate that the Kalman filter provides improved estimates of the aircraft position and velocity as compared with estimates from the more standard complementary filter. The onboard computer implementation requirements to achieve this improved performance are discussed

Modular exponentiation via the explicit Chinese remainder theorem

In this paper we consider the problem of computing xe mod m for large integers x, e, and m. This is the bottleneck in Rabin’s algorithm for testing primality, the Diffie-Hellman algorithm for exchanging cryptographic keys, and many other common algorithms

Computation of the least primitive root

Let $g(p)$ denote the least primitive root modulo $p$, and $h(p)$ the least primitive root modulo $p^2$. We computed $g(p)$ and $h(p)$ for all primes $p\le 10^{16}$. Here we present the results of that computation and prove three theorems as a consequence. In particular, we show that $g(p)<p^{5/8}$ for all primes $p>3$ and that $h(p)<p^{2/3}$ for all primes $p$

Environmental Effects on Limit-Fed Feedlot Finishing Diets

Ninety-six crossbred yearling steers were allotted to either ad libitum or 93% of ad libitum intake treatments in a 117-day winter finishing trial. Intake restriction began once the 93% treatment group was started on its finishing diet. Finishing diets were formulated to result in similar absolute intakes of nutrients and feed additives. Restricted treatment dry matter intake was lower than ad libitum as intended (P\u3c.05), but average daily gain was also less, 3.71 and 3.50 Ib per day (P\u3c.05) and resulted in similar feed/gain, 6.01 and 6.07 (P\u3e.82). These results are in contrast to two previous trials conducted during summer and mild winter/spring conditions and suggest that cold stress may affect the response to limit-feeding of feedlot finishing diets

Automatic Generation of Data Flow Diagrams From A Requirements Specification Language

Escalating manpower costs in developing systems has caused an increasing need for greater productivity in system development particularly in the analysis and design phases. Productivity in the system analysis phase can be increased with the use of computer- aided tools such as SPSL/SPSA for specifying system requirements and methodologies such as structured analysis. A structured analysis and documentation tool-the data flow diagram-allows an analyst to model and document a system with relative ease; however, the manual production of a data flow diagram is a time consuming process Combining the production of data flow diagrams with SPSL/SPSA produces a synergistic effect on the increases in productivity and ensures the use of standards andthe completenessof the diagram. This paperdescribes the problems and design of the systemMONDRIAN that generates data flow diagrams from an SPSA database. A variety of placement and routing algorithms that address the layout problem are discussed. The results of a preliminary study of the effectiveness of these algorithms and the adaptations required to improve and refine the prototype version of MONDRIAN are presented

Bragg spectroscopy of a cigar shaped Bose condensate in optical lattices

We study properties of excited states of an array of weakly coupled quasi-two-dimensional Bose condensates by using the hydrodynamic theory. We calculate multibranch Bogoliubov-Bloch spectrums and its corresponding eigenfunctions. The spectrum of the axial excited states and its eigenfunctions strongly depends on the coupling among various discrete radial modes within a given symmetry. This mode coupling is due to the presence of radial trapping potential. The multibranch nature of the Bogoliubov-Bloch spectrum and its dependence on the mode-coupling can be realized by analyzing dynamic structure factor and momentum transferred to the system in Bragg spectroscopy experiments. We also study dynamic structure factor and momentum transferred to the condensate due to the Bragg spectroscopy experiment.Comment: 7 pages, 5 figures, to appear in Journal of Physics B: Atomic, Molecular & Optical Physic

Mechanical Harvesting of Corn.

38 p