644 research outputs found
Stand-alone flat-plate photovoltaic power systems: System sizing and life-cycle costing methodology for Federal agencies
A simple methodology to estimate photovoltaic system size and life-cycle costs in stand-alone applications is presented. It is designed to assist engineers at Government agencies in determining the feasibility of using small stand-alone photovoltaic systems to supply ac or dc power to the load. Photovoltaic system design considerations are presented as well as the equations for sizing the flat-plate array and the battery storage to meet the required load. Cost effectiveness of a candidate photovoltaic system is based on comparison with the life-cycle cost of alternative systems. Examples of alternative systems addressed are batteries, diesel generators, the utility grid, and other renewable energy systems
Convergence Radii for Eigenvalues of Tri--diagonal Matrices
Consider a family of infinite tri--diagonal matrices of the form
where the matrix is diagonal with entries and the matrix
is off--diagonal, with nonzero entries The spectrum of is discrete. For small the
-th eigenvalue is a well--defined analytic
function. Let be the convergence radius of its Taylor's series about It is proved that R_n \leq C(\alpha) n^{2-\alpha} \quad \text{if} 0 \leq
\alpha <11/6.$
Further development in measuring communicative participation: identifying items to extend the applicability of the communicative participation item bank
Background: The ability to communicate is a prerequisite for participation in today’s society. To measure participation in adults with communication disorders, the Communicative Participation Item Bank (CPIB) was developed in 2006. Since then, several new PROMs have been developed to measure communication and the impact of communication disorders on participation. Moreover, the CPIB items do not all appear to be relevant to certain populations with communication problems and context of communicative participation is changing rapidly, given the increased use of digital communication forms. The purpose of this study was to identify new PROMs developed since 2006 that aim to measure (aspects of) communication, in order to select items that are suitable for expanding the Communicative Participation Item Bank to make the item bank more widely applicable (e.g., to the hearing-impaired population) and tailored to the current societal context. Methods: Medline and Embase were used to search for PROMs that aim to measure (aspects of) communication. Each new PROM as well as the CPIB, was evaluated to determine to what extent it contains items that measure communicative participation and to what extent these items capture all communicative participation domains by linking each item to the ICF Activities and Participation domains. Results: This study identified 31 new PROMs, containing 391 items that were labelled as measuring communicative participation. The majority of the 391 items measure aspects of ICF Activities and Participation domain ‘communication’, followed by the domain ‘interpersonal interactions and relationships’. The other ICF Activity and Participation domains were less often addressed. Analysis of the CPIB showed that items do not cover all domains of participation as defined in the ICF, such as the ‘major life areas’ domain. Conclusions: We found a potential pool of 391 items measuring communicative participation that could be considered for extending the CPIB. We found items in domains that are already present in the CPIB, but also items that relate to new domains, such as an item on talking with customers or clients for the ‘major life areas’ domain. Inclusion of new items in other domains would benefit the comprehensiveness of the item bank
APLICAÇÃO DE PERFIS DE VARREDURA NA ANÁLISE GEOMORFOLÓGICA DO RELEVO DE BORDA PLANÁLTICA E MAPEAMENTO DE SUPERFÍCIES ESTRUTURAIS
O presente trabalho teve como principal objetivo a aplicação de perfis de varredura para análise geomorfológica na borda planáltica entre o Segundo e Terceiro Planaltos Paranaenses. Os perfis de varredura permitem reconstituir a inclinação dos planos tangenciais às linhas de cumeada e a identificação de faixas de transição de patamares. Foram identificadas oito superfícies estruturais (SE), que são controladas e delimitadas por falhas normais e definem o Alto Estrutural de Mauá da Serra
Региоселективный синтез и свойства ацетильных производных фенолгликозидов
Региоселективный синтез и свойства ацетильных производных фенолгликозидов.
Работа посвящена выявлению реакционной способности при кислотном дезацетилировании с использованием HCl / EtOH в CHCl3, которая приводит к дезацетилированию на O-3, O-4 и O-6. Описанный реагент оказался общим и уникальным, и была получена серия 2-О-ацетиларилгликозидов. Вообще, частично ацетилированные арилгликозиды широко встречаются в природе. В частности, можно найти множество примеров 2-O-ацетиларилгликозидов.Regioselective synthesis and properties of acetyl derivatives of phenol glycosides.
The thesis is devoted to the detection of reactivity during acid deacetylation using HCl / EtOH in CHCl3, which leads to deacetylation at O-3, O-4 and O-6. The described reagent proved to be general and unique and the series of 2-О-acetyl aryl glycosides were prepared. Generally, partially acetylated aryl glycosides are widely found in nature. Particularly, many examples of 2-O-acetyl aryl glycosides can be found
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
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
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
- …