2,983 research outputs found
Pattern-Based Genetic Algorithm for Airborne Conflict Resolution
NASA has developed the Autonomous Operations Planner (AOP) airborne decision support tool to explore advanced air traffic control concepts that include delegating separation authority to aircraft. A key element of the AOP is its strategic conflict resolution (CR) algorithm, which must resolve conflicts while maintaining conformance with traffic flow management constraints. While a previous CR algorithm, which focused on broader flight plan optimization objectives as a part of conflict resolution, had successfully been developed, new research has identified the need for resolution routes the users find more acceptable (i.e., simpler and more intuitive). A new CR algorithm is presented that uses a combination of pattern-based maneuvers and a genetic algorithm to achieve these new objectives. Several lateral and vertical maneuver patterns are defined and the application of the genetic algorithm explained. A new approach to defining a conflicted fitness function using estimates of the local conflict region around a conflicted trajectory is also presented. Preliminary performance characteristics of the implemented algorithm are provided
Vibrational spectroscopy of H2+: precise evaluation of the Zeeman effect
We present an accurate computation of the g-factors of the hyperfine states
of the hydrogen molecular ion H2+. The results are in good agreement with
previous experiments, and can be tested further by rf spectroscopy. Their
implication for high-precision two-photon vibrational spectroscopy of H2+ is
also discussed. It is found that the most intense hyperfine components of
two-photon lines benefit from a very small Zeeman splitting
\u3ci\u3eGranion Soup\u3c/i\u3e
Robin had not slept. He had only pretended, in a last effort to stop his punishment, and, thank Heaven, it had worked: Rose had left off talking and fallen into slumber on her side of the bed
Four wave mixing oscillation in a semiconductor microcavity: Generation of two correlated polariton populations
We demonstrate a novel kind of polariton four wave mixing oscillation. Two
pump polaritons scatter towards final states that emit two beams of equal
intensity, separated both spatially and in polarization with respect to the
pumps. The measurement of the intensity fluctuations of the emitted light
demonstrates that the final states are strongly correlated.Comment: 5 pages, 5 figures In this strongly revised version several new
experimental data are adde
Infrared and Raman spectroscopic studies of structural variations in minerals from Apollo 11, 12, 14 and 15 samples, volume 3
Infrared and Raman vibrational spectroscopic data, yielding direct information on molecular structure, were obtained for single grains ( 150 microns) of minerals, basalts, and glasses isolated from Apollo 11, 12, 14, and 15 rock and dust samples, and for grains in Apollo 14 polished butt samples. From the vibrational data, specification substitutions were determined for the predominant silicate minerals of plagioclase, pyroxene, and olivine. Unique spectral variations for grains of K-feldspar, orthopyroxene, pyroxenoid, and ilmenite were observed to exceed the ranges of terrestrial samples, and these variations may be correlatable with formation histories. Alpha-quartz was isolated as pure single grains, in granitic grains composited with sanidine, and in unique grains that were intimately mixed with varying amounts of glass. Accessory minerals of chromite and ulvospinel were isolated as pure grains and structurally characterized from their distinctive infrared spectra. Fundamental vibrations of the SiO4 tetrahedra in silicate minerals were used to classify bulk compositions in dust sieved fractions, basalt grains and glass particles, and to compare modal characteristics for maria, highland and rille samples. No hydrated minerals were found in any of the samples studied, indicating anhydrous formation conditions
Level density and level-spacing distributions of random, self-adjoint, non-Hermitian matrices
We investigate the level-density and level-spacing distribution
of random matrices where is a (diagonal)
inner-product and is a random, real symmetric or complex Hermitian matrix
with independent entries drawn from a probability distribution with zero
mean and finite higher moments. Although not Hermitian, the matrix is
self-adjoint with respect to and thus has purely real eigenvalues. We find
that the level density is independent of the underlying
distribution , is solely characterized by , and therefore generalizes
Wigner's semicircle distribution . We find that the level-spacing
distributions are independent of , are dependent upon the
inner-product and whether is real or complex, and therefore generalize
the Wigner's surmise for level spacing. Our results suggest -dependent
generalizations of the well-known Gaussian Orthogonal Ensemble (GOE) and
Gaussian Unitary Ensemble (GUE) classes.Comment: 5 pages, 5 figures, revised tex
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