149,037 research outputs found
Use of composite rotations to correct systematic errors in NMR quantum computation
We implement an ensemble quantum counting algorithm on three NMR
spectrometers with 1H resonance frequencies of 500, 600 and 750 MHz. At higher
frequencies, the results deviate markedly from naive theoretical predictions.
These systematic errors can be attributed almost entirely to off-resonance
effects, which can be substantially corrected for using fully-compensating
composite rotation pulse sequences originally developed by Tycko. We also
derive an analytic expression for generating such sequences with arbitrary
rotation angles.Comment: 8 pages RevTex including 7 PostScript figures (18 subfigures
Orbit targeting specialist function: Level C formulation requirements
A definition of the level C requirements for onboard maneuver targeting software is provided. Included are revisions of the level C software requirements delineated in JSC IN 78-FM-27, Proximity Operations Software; Level C Requirements, dated May 1978. The software supports the terminal phase midcourse (TPM) maneuver, braking and close-in operations as well as supporting computation of the rendezvous corrective combination maneuver (NCC), and the terminal phase initiation (TPI). Specific formulation is contained here for the orbit targeting specialist function including the processing logic, linkage, and data base definitions for all modules. The crew interface with the software is through the keyboard and the ORBIT-TGT display
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User roles in asynchronous distributed collaborative idea generation
This paper presents the findings of an exploratory study within a real-life context that investigates participant behaviour and emergent user roles in asynchronous distributed collaborative idea generation by a defined community of users. In the study, a high-fidelity prototype of an online virtual ideas room was built and used by a Community of Interest consisting of representatives from 10 different voluntary organisations spread across Denmark. The study revealed five user roles, which the authors propose that future asynchronous distributed collaborative idea generation platforms should consider
Rendezvous radar requirements analysis for mission 3B
Data are presented verifying the compatibility of currently proposed rendezvous radar measurement accuracies with Mission 3B rendezvous requirements. In addition, data presented indicate a potential for increasing the acceptable time lag between termination of thrusting and availability of accurate measurement data. Additional investigation is recommended to define any acceptable time lag above the current proposed value. Finally, Mission 3B rendezvous performance is shown to be sensitive to variations in the relative downrange position dispersions at insertion. It is therefore recommended that insertion relative state dispersions used in studies of 3B rendezvous be reviewed when results of 3B ascent dispersion studies are available
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Using infrared thermography for monitoring thermal efficiency of buildings - case studies from Nottingham Trent University
Global warming and the continuous increase of energy cost are driving the need for reducing energy consumption. Buildings are responsible for approximately 50% of the UK energy consumption. Major part of this consumption is for heating and air conditioning of buildings. Nottingham Trent University is a leading university in the UK in relation to improving the performance of its buildings in order to improve insulation and energy consumption. The experimental case studies presented in this paper highlights some of the new measures taken to reduce energy consumption and enhance the sustainability of the University buildings. Infrared thermography is used to evaluate insulation measures and energy performance. The results indicate that enhanced insulation combined with modern sustainable technologies can significantly reduce energy consumption
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