20,122 research outputs found
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.
Quantum capacitor with discrete charge-anticharge: spectrum and forces
The quantum capacitor with discrete charge is modeled by a Hamiltonian
containing an inductive intrinsic term (tunnel effect between plates). The
spectrum is obtained using a double Hilbert space. Fluctuations in the
charge-anticharge pairs (zero total charge) give rise to an elementary
attraction which is compared to the Casimir force. In this case, the
field-fluctuations force could be also interpreted as charge-fluctuations
force
Anomalously Slow Cross Symmetry Phase Relaxation, Thermalized Non-Equilibrated Matter and Quantum Computing Beyond the Quantum Chaos Border
Thermalization in highly excited quantum many-body system does not
necessarily mean a complete memory loss of the way the system was formed. This
effect may pave a way for a quantum computing, with a large number of qubits
--1000, far beyond the quantum chaos border. One of the
manifestations of such a thermalized non-equilibrated matter is revealed by a
strong asymmetry around 90 c.m. of evaporating proton yield in the
Bi(,p) photonuclear reaction. The effect is described in terms of
anomalously slow cross symmetry phase relaxation in highly excited quantum
many-body systems with exponentially large Hilbert space dimensions. In the
above reaction this phase relaxation is about eight orders of magnitude slower
than energy relaxation (thermalization).Comment: Published in SIGMA (Symmetry, Integrability and Geometry: Methods and
Applications) at http://www.emis.de/journals/SIGMA
Improvement and analysis of a pseudo random bit generator by means of cellular automata
In this paper, we implement a revised pseudo random bit generator based on a
rule-90 cellular automaton. For this purpose, we introduce a sequence matrix
H_N with the aim of calculating the pseudo random sequences of N bits employing
the algorithm related to the automaton backward evolution. In addition, a
multifractal structure of the matrix H_N is revealed and quantified according
to the multifractal formalism. The latter analysis could help to disentangle
what kind of automaton rule is used in the randomization process and therefore
it could be useful in cryptanalysis. Moreover, the conditions are found under
which this pseudo random generator passes all the statistical tests provided by
the National Institute of Standards and Technology (NIST)Comment: 20 pages, 12 figure
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