590 research outputs found
Module utilization committee
Photovoltaic collector modules were declared surplus to the needs of the U.S. Dept. of Energy. The Module Utilization Committee was formed to make appropriate disposition of the surplus modules on a national basis and to act as a broker for requests for these modules originating outside of the National Photovoltaics Program
Orientation dependence of the sticking probability of NO at Ni(100)
Fecher GH, Volkmer M, Pawlitzky B, Böwering N, Heinzmann U. Orientation dependence of the sticking probability of NO at Ni(100). Vacuum. 1990;41(1-3):265-268
High-level feature detection from video in TRECVid: a 5-year retrospective of achievements
Successful and effective content-based access to digital
video requires fast, accurate and scalable methods to determine the video content automatically. A variety of contemporary approaches to this rely on text taken from speech within the video, or on matching one video frame against others using low-level characteristics like
colour, texture, or shapes, or on determining and matching objects appearing within the video. Possibly the most important technique, however, is one which determines the presence or absence of a high-level or semantic feature, within a video clip or shot. By utilizing dozens, hundreds or even thousands of such semantic features we can support many kinds of content-based video navigation. Critically however, this depends on being able to determine whether each feature is or is not present in a video clip.
The last 5 years have seen much progress in the development of techniques to determine the presence of semantic features within video. This progress can be tracked in the annual TRECVid benchmarking activity where dozens of research groups measure the effectiveness of their techniques on common data and using an open, metrics-based approach. In this chapter we summarise the work
done on the TRECVid high-level feature task, showing the
progress made year-on-year. This provides a fairly comprehensive statement on where the state-of-the-art is regarding this important task, not just for one research group or for one approach, but across the spectrum. We then use this past and on-going work as a basis for highlighting the trends that are emerging in this area, and the questions which remain to be addressed before we can
achieve large-scale, fast and reliable high-level feature detection on video
Sturm-Liouville operators on time scales
We establish the connection between Sturm-Liouville equations on time scales
and Sturm--Liouville equations with measure-valued coefficients. Based on this
connection we generalize several results for Sturm-Liouville equations on time
scales which have been obtained by various authors in the past.Comment: 12 page
Translating Ultrasound into Clinical Practice for the Assessment of Swallowing and Laryngeal Function: A Speech and Language Pathology-Led Consensus Study
Ultrasound (US) has an emerging evidence base for the assessment of swallowing and laryngeal function. Accessibility and technological advances support the use of US as a clinical assessment tool; however, there is insufficient evidence to support its translation into clinical practice. This study aimed to establish consensus on the priorities for translation of US into clinical practice for the assessment of swallowing and laryngeal function. Nominal Group Technique (NGT) was used as a formal method of consensus development. Clinicians and academics, all members of an international US working group, were invited to participate in the study. Two NGT meetings were held, where participants silently generated and then shared ideas. Participants anonymously ranked items. Rankings were aggregated before participants re-ranked items in order of priority. Discussions regarding rankings were recorded and transcribed to inform analysis. Member-checking with participants informed the final analysis. Participants (n = 15) were speech and language pathologists, physiotherapists and sonographers representing six countries. Fifteen items were identified and prioritised 1â13 (including two equally ranked items). Reliability, validity and normative data emerged as key areas for research while development of training protocols and engagement with stakeholders were considered vital to progressing US into practice. Analysis revealed common themes that might be addressed together in research, in addition to the ranked priority. A measured approach to the translation of US into clinical practice will enable effective implementation of this tool. Priorities may evolve as clinical and professional contexts shift, but this study provides a framework to advance research and clinical practice in this field
GREGOR Fabry-Perot Interferometer - status report and prospects
The GREGOR Fabry-Perot Interferometer (GFPI) is one of three first-light
instruments of the German 1.5-meter GREGOR solar telescope at the Observatorio
del Teide, Tenerife, Spain. The GFPI allows fast narrow-band imaging and
post-factum image restoration. The retrieved physical parameters will be a
fundamental building block for understanding the dynamic Sun and its magnetic
field at spatial scales down to 50 km on the solar surface. The GFPI is a
tunable dual-etalon system in a collimated mounting. It is designed for
spectropolarimetric observations over the wavelength range from 530-860 nm with
a theoretical spectral resolution of R ~ 250,000. The GFPI is equipped with a
full-Stokes polarimeter. Large-format, high-cadence CCD detectors with powerful
computer hard- and software enable the scanning of spectral lines in time spans
equivalent to the evolution time of solar features. The field-of-view of 50" x
38" covers a significant fraction of the typical area of active regions. We
present the main characteristics of the GFPI including advanced and automated
calibration and observing procedures. We discuss improvements in the optical
design of the instrument and show first observational results. Finally, we lay
out first concrete ideas for the integration of a second FPI, the Blue Imaging
Solar Spectrometer, which will explore the blue spectral region below 530 nm.Comment: 18 pages, 9 Figures, 4 Tables, "Astronomical Telescopes and
Instrumentation", Amsterdam, 1-6 July 2012, SPIE Proc. 8446-276, in pres
The GREGOR Fabry-P\'erot Interferometer
The GREGOR Fabry-P\'erot Interferometer (GFPI) is one of three first-light
instruments of the German 1.5-meter GREGOR solar telescope at the Observatorio
del Teide, Tenerife, Spain. The GFPI uses two tunable etalons in collimated
mounting. Thanks to its large-format, high-cadence CCD detectors with
sophisticated computer hard- and software it is capable of scanning spectral
lines with a cadence that is sufficient to capture the dynamic evolution of the
solar atmosphere. The field-of-view (FOV) of 50" x 38" is well suited for quiet
Sun and sunspot observations. However, in the vector spectropolarimetric mode
the FOV reduces to 25" x 38". The spectral coverage in the spectroscopic mode
extends from 530-860 nm with a theoretical spectral resolution R of about
250,000, whereas in the vector spectropolarimetric mode the wavelength range is
at present limited to 580-660 nm. The combination of fast narrow-band imaging
and post-factum image restoration has the potential for discovery science
concerning the dynamic Sun and its magnetic field at spatial scales down to
about 50 km on the solar surface.Comment: 14 pages, 17 figures, 4 tables; pre-print of AN 333, p.880-893, 2012
(AN special issue to GREGOR
A retrospective of the GREGOR solar telescope in scientific literature
In this review, we look back upon the literature, which had the GREGOR solar
telescope project as its subject including science cases, telescope subsystems,
and post-focus instruments. The articles date back to the year 2000, when the
initial concepts for a new solar telescope on Tenerife were first presented at
scientific meetings. This comprehensive bibliography contains literature until
the year 2012, i.e., the final stages of commissioning and science
verification. Taking stock of the various publications in peer-reviewed
journals and conference proceedings also provides the "historical" context for
the reference articles in this special issue of Astronomische
Nachrichten/Astronomical Notes.Comment: 6 pages, 2 color figures, this is the pre-peer reviewed version of
Denker et al. 2012, Astron. Nachr. 333, 81
Spectropolarimetric observations of an arch filament system with the GREGOR solar telescope
Arch filament systems occur in active sunspot groups, where a fibril
structure connects areas of opposite magnetic polarity, in contrast to active
region filaments that follow the polarity inversion line. We used the GREGOR
Infrared Spectrograph (GRIS) to obtain the full Stokes vector in the spectral
lines Si I 1082.7 nm, He I 1083.0 nm, and Ca I 1083.9 nm. We focus on the
near-infrared calcium line to investigate the photospheric magnetic field and
velocities, and use the line core intensities and velocities of the helium line
to study the chromospheric plasma. The individual fibrils of the arch filament
system connect the sunspot with patches of magnetic polarity opposite to that
of the spot. These patches do not necessarily coincide with pores, where the
magnetic field is strongest. Instead, areas are preferred not far from the
polarity inversion line. These areas exhibit photospheric downflows of moderate
velocity, but significantly higher downflows of up to 30 km/s in the
chromospheric helium line. Our findings can be explained with new emerging flux
where the matter flows downward along the fieldlines of rising flux tubes, in
agreement with earlier results.Comment: Proceedings 12th Potsdam Thinkshop to appear in Astronomische
Nachrichte
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