975 research outputs found
Turboprop cargo aircraft systems study
The effects of using advanced turboprop propulsion systems to reduce the fuel consumption and direct operating costs of cargo aircraft were studied, and the impact of these systems on aircraft noise and noise prints around a terminal area was determined. Parametric variations of aircraft and propeller characteristics were investigated to determine their effects on noiseprint areas, fuel consumption, and direct operating costs. From these results, three aircraft designs were selected and subjected to design refinements and sensitivity analyses. Three competitive turbofan aircraft were also defined from parametric studies to provide a basis for comparing the two types of propulsion
Turboprop Cargo Aircraft Systems study, phase 1
The effects of advanced propellers (propfan) on aircraft direct operating costs, fuel consumption, and noiseprints were determined. A comparison of three aircraft selected from the results with competitive turbofan aircraft shows that advanced turboprop aircraft offer these potential benefits, relative to advanced turbofan aircraft: 21 percent fuel saving, 26 percent higher fuel efficiency, 15 percent lower DOCs, and 25 percent shorter field lengths. Fuel consumption for the turboprop is nearly 40 percent less than for current commercial turbofan aircraft. Aircraft with both types of propulsion satisfy current federal noise regulations. Advanced turboprop aircraft have smaller noiseprints at 90 EPNdB than advanced turbofan aircraft, but large noiseprints at 70 and 80 EPNdB levels, which are usually suggested as quietness goals. Accelerated development of advanced turboprops is strongly recommended to permit early attainment of the potential fuel saving. Several areas of work are identified which may produce quieter turboprop aircraft
Combining geometric edge detectors for feature detection
We propose a novel framework for the analysis and modeling of discrete edge filters, based on the notion of signed rays. This framework will allow us to easily deduce the geometric and localization properties of a family of first-order filters, and use this information to design custom filter banks for specific applications. As an example, a set of angle-selective corner detectors is constructed for the detection of buildings in video sequences. This clearly illustrates the merit of the theory for solving practical recognition problems
Knime4Bio: a set of custom nodes for the interpretation of next-generation sequencing data with KNIMEâ
Summary: Analysing large amounts of data generated by next-generation sequencing (NGS) technologies is difficult for researchers or clinicians without computational skills. They are often compelled to delegate this task to computer biologists working with command line utilities. The availability of easy-to-use tools will become essential with the generalization of NGS in research and diagnosis. It will enable investigators to handle much more of the analysis. Here, we describe Knime4Bio, a set of custom nodes for the KNIME (The Konstanz Information Miner) interactive graphical workbench, for the interpretation of large biological datasets. We demonstrate that this tool can be utilized to quickly retrieve previously published scientific findings
Forward analysis of N scattering with an expansion method
The N forward scattering data are analyzed using an expansion method,
where the invariant amplitudes are represented by expansions satisfying the
forward dispersion relations. The experimental errors of the data are taken
into account through the covariance matrix of the coefficients of the
expansions in a careful error analysis. From the results, some coefficients,
, of the subthreshold expansions have been calculated with proper
error bars.Comment: 5 pages, 4 figures. v2: Added some references. v3: Corrected
hyphenatio
Observing Spontaneous Strong Parity Violation in Heavy-Ion Collisions
We discuss the problem of observing spontaneous parity and CP violation in
collision systems. We discuss and propose observables which may be used in
heavy-ion collisions to observe such violations, as well as event-by-event
methods to analyze the data. Finally, we discuss simple monte-carlo models of
these CP violating effects which we have used to develop our techniques and
from which we derive rough estimates of sensitivities to signals which may be
seen at RHIC
Unquenching the scalar glueball
Computations in the quenched approximation on the lattice predict the
lightest glueball to be a scalar in the 1.5-1.8 GeV region. Here we calculate
the dynamical effect the coupling to two pseudoscalars has on the mass, width
and decay pattern of such a scalar glueball. These hadronic interactions allow
mixing with the scalar nonet, which is largely fixed by the
well-established K_0^*(1430). This non-perturbative mixing means that, if the
pure gluestate has a width to two pseudoscalar channels of ~100 MeV as
predicted on the lattice, the resulting hadron has a width to these channels of
only ~30 MeV with a large eta-eta component. Experimental results need to be
reanalyzed in the light of these predictions to decide if either the f_0(1500)
or an f_0(1710) coincides with this dressed glueball.Comment: 12 pages, LaTex, 3 Postscript figure
Study of the reaction pbar p -> phi phi from 1.1 to 2.0 GeV/c
A study has been performed of the reaction pbar p -> 4K using in-flight
antiprotons from 1.1 to 2.0 GeV/c incident momentum interacting with a hydrogen
jet target. The reaction is dominated by the production of a pair of phi
mesons. The pbar p -> phi phi cross section rises sharply above threshold and
then falls continuously as a function of increasing antiproton momentum. The
overall magnitude of the cross section exceeds expectations from a simple
application of the OZI rule by two orders of magnitude. In a fine scan around
the xi/f_J(2230) resonance, no structure is observed. A limit is set for the
double branching ratio B(xi -> pbar p) * B(xi -> phi phi) < 6e-5 for a spin 2
resonance of M = 2.235 GeV and Width = 15 MeV.Comment: 13 pages, 13 figures, 2 tables, Latex. To be published in Phys. Rev.
Determination of hadronic partial widths for scalar-isoscalar resonances f0(980), f0(1300), f0(1500), f_0(1750) and the broad state f0(1530^{+90}_{-250})
In the article of V.V. Anisovich et al., Yad. Fiz. 63, 1489 (2000), the
K-matrix solutions for the wave IJ^{PC}=00^{++} were obtained in the mass
region 450 - 1900 MeV where four resonances f0(980), f0(1300), f0(1500),
f0(1750) and the broad state f0(1530^{+90}_{-250}) are located. Based on these
solutions, we determine partial widths for scalar-isoscalar states decaying
into the channels pi-pi, K-anti K, eta-eta, eta-eta', pi-pi-pi-pi and
corresponding decay couplings.Comment: Some typos were correcte
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