10,295 research outputs found
Voice integrated systems
The program at Naval Air Development Center was initiated to determine the desirability of interactive voice systems for use in airborne weapon systems crew stations. A voice recognition and synthesis system (VRAS) was developed and incorporated into a human centrifuge. The speech recognition aspect of VRAS was developed using a voice command system (VCS) developed by Scope Electronics. The speech synthesis capability was supplied by a Votrax, VS-5, speech synthesis unit built by Vocal Interface. The effects of simulated flight on automatic speech recognition were determined by repeated trials in the VRAS-equipped centrifuge. The relationship of vibration, G, O2 mask, mission duration, and cockpit temperature and voice quality was determined. The results showed that: (1) voice quality degrades after 0.5 hours with an O2 mask; (2) voice quality degrades under high vibration; and (3) voice quality degrades under high levels of G. The voice quality studies are summarized. These results were obtained with a baseline of 80 percent recognition accuracy with VCS
NIR and optical observations of the failed outbursts of black hole binary XTE J1550-564
A number of low mass X-ray binaries (LMXBs) undergo "failed outbursts" in
which, instead of evolving through the canonical states, they remain in a hard
state throughout the outburst. While the sources of X-ray and radio emission in
the hard state are relatively well understood, the origin of the near infrared
(NIR) and optical emission is more complex though it likely stems from an
amalgam of different emission processes, occurring as it does, at the
intersecting wavelengths of those processes. We aim to identify the NIR/optical
emission region(s) during a number of failed outbursts of one such low mass
X-ray binary and black hole candidate, XTE J1550-564, in order to confirm or
refute their classification as hard-state, failed outbursts. We present unique
NIR/optical images and spectra, obtained with the ESO-New Technology Telescope,
during the failed outbursts of 2001 and 2000. We compare the NIR/optical
photometric, timing, and spectral properties with those expected for the
different emission mechanisms in the various LMXB states. The NIR/optical data
are consistent with having come from reprocessing of X-rays in the accretion
disk, with no evidence of direct thermal emission from the disk itself.
However, the observed variability in high-cadence NIR light curves suggest that
the radio jet extends and contributes to the NIR wavelengths. We find that
these failed outbursts did not transition to an intermediate state but remained
in a true, hard state where there was no sign of jet quenching or deviation
from the observed hard state correlations.Comment: Accepted to Astronomy & Astrophysics (8 pages
Stereoisomer libraries: Total synthesis of all 16 stereoisomers of the pine sawfly sex pheromone by a fluorous mixture-synthesis approach
All 16 stereoisomers of the sex pheromone of pine sawfly (3,7,11-trimethylundecanol propanoate ester) have been synthesized on a 10- to 20-mg scale by a split-parallel fluorous mixture-synthesis approach. Spectral data obtained for all 32 compounds (16 alcohols and the corresponding propionates) matched well with published data, thereby validating the fluorous-tag encoding of diastereoisomers. This fluorous-tag encoding method is recommended for the efficient synthesis of multiple stereoisomers for spectroscopic studies, biological tests, or other structure-function relationships
Development of LANDSAT Derived Forest Cover Information for Integration into Adirondack Park GIS
Based upon observed changes in timber harvest practices partially attributable to forest biomass removable for energy supply purposes, the Adirondack Park Agency began in 1979 a multi-year project to implement a digital geographic information system (GIS). An initial developmental task was an inventory of forest cover information and analysis of forest resource change and availability. While developing the GIS, a pilot project was undertaken to evaluate the usefulness of LANDSAT derived land cover information for this purpose, and to explore the integration of LANDSAT data into the GIS. The prototype LANDSAT analysis project involved: (1) the use of both recent and historic data to derive land cover information for two dates; and (2) comparison of land cover over time to determine quantitative and geographic changes. The "recent data," 1978 full foliage data over portions of four LANDSAT scenes, was classified, using ground truth derived training samples in various forested and non-forested categories. Forested categories include the following: northern hardwoods, pine, spruce-fir, and pine plantation, while nonforested categories include wet-conifer, pasture, grassland, urban, exposed soil, agriculture, and water
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A search for near infrared counterparts of 3 pulsar wind nebulae
While pulsar wind nebulae (PWNe) and their associated isolated pulsars are
commonly detected at X-ray energies, they are much rarer at near infrared (nIR)
and optical wavelengths. Here we examine three PWN systems in the Galactic
plane - IGR J14003-6326, HESS J1632-478 and IGR J18490-0000 - in a bid to
identify optical/nIR emission associated with either the extended PWNe or their
previously detected X-ray point sources. We obtain optical/nIR images of the
three fields with the ESO - New Technology Telescope and apply standard
photometric and astrometric calibrations. We find no evidence of any extended
emission associated with the PWNe in any of the fields; neither do we find any
new counterparts to the X-ray point sources, except to confirm the magnitude of
the previously identified counterpart candidate of IGR J18490-0000. Further
observations are required to confirm the association of the nIR source to IGR
J18490-0000 and to detect counterparts to IGR J14003-6326 and HESS J1632-478,
while a more accurate X-ray position is required to reduce the probability of a
chance superposition in the field of the latter.Comment: Accepted to A&A (4 pages, 1 figure
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