2,479 research outputs found
Remote Sensing of Giant Reed with QuickBird Satellite Imagery
QuickBird high resolution (2.8 m) satellite imagery was
evaluated for distinguishing giant reed (
Arundo donax
L.) infestations
along the Rio Grande in southwest Texas. (PDF has 5 pages.
Light Reflectance Characteristics and Remote Sensing of Waterlettuce
Waterlettuce (
Pistia stratiotes
L.) is a free-floating exotic
aquatic weed that often invades and clogs waterways in the
southeastern United States. A study was conducted to evaluate
the potential of using remote sensing technology to distinguish
infestations of waterlettuce in Texas waterways. Field
reflectance measurements showed that waterlettuce had
higher visible green reflectance than associated plant species.
Waterlettuce could be detected in both aerial color- infrared
(CIR) photography and videography where it had
light pink to pinkish-white image tonal responses. Computer
analysis of CIR photographic and videographic images had
overall accuracy assessments of 86% and 84%, respectively. (PDF contains 6 pages.
Estimating total standing herbaceous biomass production with LANDSAT MSS digital data
Rangeland biomass data were correlated with spectral vegetation indices, derived from LANDSAT MSS data. LANDSAT data from five range and three other land use sites in Willacv and Cameron Counties were collected on October 17 and December 10, 1975, and on July 31 and September 23, 1976. The overall linear correlation of total standing herbaceous biomass with the LANDSAT derived perpendicular vegetation index was highly significant (r = 0.90**) for these four dates. The standard error of estimate was 722 kg/ha. Biomass data were recorded for two of these range sites for 8 months (March through October) during the 1976 growing season. Standing green biomass accounted for most of the increase in herbage, starting in June and ending about September and October. These results indicate that satellite data may be useful for the estimation of total standing herbaceous biomass production that could aid range managers in assessing range condition and animal carrying capacities of large and inaccessible range holdings
The quantum-classical crossover of a field mode
We explore the quantum-classical crossover in the behaviour of a quantum
field mode. The quantum behaviour of a two-state system - a qubit - coupled to
the field is used as a probe. Collapse and revival of the qubit inversion form
the signature for quantum behaviour of the field and continuous Rabi
oscillations form the signature for classical behaviour of the field. We
demonstrate both limits in a single model for the full coupled system, for
states with the same average field strength, and so for qubits with the same
Rabi frequency.Comment: 6 pages, 3 figures (in this version the figures, text and references
have all been expanded
Non-linear dynamics, entanglement and the quantum-classical crossover of two coupled SQUID rings
We explore the quantum-classical crossover of two coupled, identical,
superconducting quantum interference device (SQUID) rings. We note that the
motivation for this work is based on a study of a similar system comprising two
coupled Duffing oscillators. In that work we showed that the entanglement
characteristics of chaotic and periodic (entrained) solutions differed
significantly and that in the classical limit entanglement was preserved only
in the chaotic-like solutions. However, Duffing oscillators are a highly
idealised toy model. Motivated by a wish to explore more experimentally
realisable systems we now extend our work to an analysis of two coupled SQUID
rings. We observe some differences in behaviour between the system that is
based on SQUID rings rather than on Duffing oscillators. However, we show that
the two systems share a common feature. That is, even when the SQUID ring's
trajectories appear to follow (semi) classical orbits entanglement persists.Comment: 9 pages, 4 figures. Published as part of the proceedings of the 32nd
International Workshop on Condensed Matter Theories (CMT32) Loughborough
University, 2008 (invited paper
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