27,148 research outputs found
An Interface for Remote Sensing Digital Image Systems and Geographic Information Systems
An interfacing technique, zonation algorithms (ZONAL), which provides a means of utilizing LANDSAT information in a polygon-based geographic information system (GIS) is discussed. The ZONAL mechanisms are based on the use of existing GIS polynomial layer, thereby making the process entirely automated
Real-time in-flight thrust calculation on a digital electronic engine control-equipped F100 engine in an F-15 airplane
Computer algorithms which calculate in-flight engine and aircraft performance real-time are discussed. The first step was completed with the implementation of a real-time thrust calculation program on a digital electronic engine control (DEEC) equiped F100 engine in an F-15 aircraft. The in-flight thrust modifications that allow calculations to be performed in real-time, to compare results to predictions, are presented
Test and evaluation of the HIDEC engine uptrim algorithm
The highly integrated digital electronic control (HIDEC) program will demonstrate and evaluate the improvements in performance and mission effectiveness that result from integrated engine-airframe control systems. Performance improvements will result from an adaptive engine stall margin mode, a highly integrated mode that uses the airplane flight conditions and the resulting inlet distortion to continuously compute engine stall margin. When there is excessive stall margin, the engine is uptrimmed for more thrust by increasing engine pressure ratio (EPR). The EPR uptrim logic has been evaluated and implemented into computer simulations. Thrust improvements over 10 percent are predicted for subsonic flight conditions. The EPR uptrim was successfully demonstrated during engine ground tests. Test results verify model predictions at the conditions tested
Initial behavioural and attitudinal responses to influenza A, H1N1 ('swine flu')
Copyright © 2010 by the BMJ Publishing Group Ltd. All rights reserved.This study was sponsored by Canadian Institute of Health Research (CIHR), and
supported by the Community Coalition Concerned about SARS and other community organisations in the great Toronto area
A modified proximity approach in the fusion of heavy-ions
By using a suitable set of the surface energy coefficient, nuclear radius,
and universal function, the original proximity potential 1977 is modified. The
overestimate of the data by 4 % reported in the literature is significantly
reduced. Our modified proximity potential reproduces the experimental data
nicely compared to its older versions.Comment: 9 pages, 5 figures, Chin. Phys. lett.(2010) in pres
Archive data base and handling system for the Orbiter flying qualities experiment program
The OFQ archives data base and handling system assembled as part of the Orbiter Flying Qualities (OFQ) research of the Orbiter Experiments Program (EOX) are described. The purpose of the OFQ archives is to preserve and document shuttle flight data relevant to vehicle dynamics, flight control, and flying qualities in a form that permits maximum use for qualified users. In their complete form, the OFQ archives contain descriptive text (general information about the flight, signal descriptions and units) as well as numerical time history data. Since the shuttle program is so complex, the official data base contains thousands of signals and very complex entries are required to obtain data. The OFQ archives are intended to provide flight phase oriented data subsets with relevant signals which are easily identified for flying qualities research
Feedback control optimisation of ESR experiments
Numerically optimised microwave pulses are used to increase excitation
efficiency and modulation depth in electron spin resonance experiments
performed on a spectrometer equipped with an arbitrary waveform generator. The
optimisation procedure is sample-specific and reminiscent of the magnet
shimming process used in the early days of nuclear magnetic resonance -- an
objective function (for example, echo integral in a spin echo experiment) is
defined and optimised numerically as a function of the pulse waveform vector
using noise-resilient gradient-free methods. We found that the resulting shaped
microwave pulses achieve higher excitation bandwidth and better echo modulation
depth than the pulse shapes used as the initial guess. Although the method is
theoretically less sophisticated than simulation based quantum optimal control
techniques, it has the advantage of being free of the linear response
approximation; rapid electron spin relaxation also means that the optimisation
takes only a few seconds. This makes the procedure fast, convenient, and easy
to use. An important application of this method is at the final stage of the
implementation of theoretically designed pulse shapes: compensation of pulse
distortions introduced by the instrument. The performance is illustrated using
spin echo and out-of-phase electron spin echo envelope modulation experiments.
Interface code between Bruker SpinJet arbitrary waveform generator and Matlab
is included in versions 2.2 and later of the Spinach library
Application of remote sensing technology to land evaluation, planning utilization of land resources, and assessment of westland habitat in eastern South Dakota, parts 1 and 2
The author has identified the following significant results. LANDSAT fulfilled the requirements for general soils and land use information. RB-57 imagery was required to provide the information and detail needed for mapping soils for land evaluation. Soils maps for land evaluation were provided on clear mylar at the scale of the county highway map to aid users in locating mapping units. Resulting mapped data were computer processed to provided a series of interpretive maps (land value, limitations to development, etc.) and area summaries for the users
Liquid-Drop Model and Quantum Resistance Against Noncompact Nuclear Geometries
The importance of quantum effects for exotic nuclear shapes is demonstrated.
Based on the example of a sheet of nuclear matter of infinite lateral
dimensions but finite thickness, it is shown that the quantization of states in
momentum space, resulting from the confinement of the nucleonic motion in the
conjugate geometrical space, generates a strong resistance against such a
confinement and generates restoring forces driving the system towards compact
geometries. In the liquid-drop model, these quantum effects are implicitly
included in the surface energy term, via a choice of interaction parameters, an
approximation that has been found valid for compact shapes, but has not yet
been scrutinized for exotic shapes.Comment: 9 pages with 3 figure
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