3,183 research outputs found
Video signal processing system uses gated current mode switches to perform high speed multiplication and digital-to-analog conversion
Video signal processor uses special-purpose integrated circuits with nonsaturating current mode switching to accept texture and color information from a digital computer in a visual spaceflight simulator and to combine these, for display on color CRT with analog information concerning fading
A note on the comparison of three near infrared reflectance spectroscopy calibration strategies for assessing herbage quality of ryegrass
peer-reviewedPerennial ryegrass (n = 1,836), Italian ryegrass (n = 137) and hybrid ryegrass (n =
103) herbage was taken from harvested plots from the Irish national variety evaluation
scheme and analysed for in vitro dry matter digestibility, water soluble carbohydrate
concentration, crude protein concentration and buffering capacity. Spectral data were
obtained using near infrared reflectance spectroscopy and three calibration strategies
(global, species-specific or local) were utilised to relate the reference values to the
spectral data. The local strategy generally provided the poorest estimation of herbage
composition, with global and species-specific calibration strategies producing similarly
accurate estimates of each quality trait. The higher accuracy and easier maintenance of
the global strategy make it the recommended calibration method for analysing quality
of ryegrass.Department of Agriculture, Food and the
Marine Research Stimulus Fund (07 526
Comparison of herbage yield, nutritive value and ensilability traits of three ryegrass species evaluated for the Irish Recommended List
peer-reviewedThis study examined 169 of the newest varieties of three ryegrass species, perennial (Lolium perenne L.), Italian (Lolium multiflorum Lam.) and hybrid (Lolium boucheanum Kunth), from Recommended List trials in Ireland. The traits examined were yield, dry matter concentration, three nutritive value traits (in vitro dry matter digestibility, water-soluble carbohydrate on a dry matter basis and crude protein concentration) and two ensilability traits (buffering capacity and water soluble carbohydrate concentration on an aqueous phase basis). Varietal monocultures of each species underwent a six cut combined simulated grazing and silage management in each of two years following sowing. Perennial ryegrass yielded less than both other species in one-year-old swards, but less than only Italian ryegrass in two-year-old swards, but generally had the higher in vitro dry matter digestibility and crude protein values. Italian ryegrass displayed the most favourable ensilability characteristics of the three species with perennial ryegrass less favourable and hybrid ryegrass intermediate. Overall, despite the high yields and favourable nutritive value and ensilability traits recorded, the general differences between the three ryegrass species studied were in line with industry expectations. These findings justify assessing the nutritive value and ensilability of ryegrass species, in addition to yield, to allow farmers select species that match farming enterprise requirements.We acknowledge the Department of Agriculture, Food and the Marine for funding provided through the Research Stimulus Fund (07 526
Faint, moving objects in the Hubble Deep Field: components of the dark halo?
The deepest optical image of the sky, the Hubble Deep Field (HDF), obtained
with the Hubble Space Telescope (HST) in December 1995, has been compared to a
similar image taken in December 1997. Two very faint, blue, isolated and
unresolved objects are found to display a substantial apparent proper motion,
23+/-5 mas/yr and 26+/-5 mas/yr; a further three objects at the detection limit
of the second epoch observations may also be moving. Galactic structure models
predict a general absence of stars in the color-magnitude range in which these
objects are found. However, these observations are consistent with
recently-developed models of old white dwarfs with hydrogen atmospheres, whose
color, contrary to previous expectations, has been shown to be blue. If these
apparently moving objects are indeed old white dwarfs with hydrogen atmospheres
and masses near 0.5 M_Sun, they have ages of approximately 12 Gyr, and a local
mass density that is sufficient, within the large uncertainties arising from
the small size of the sample, to account for the entire missing Galactic
dynamical mass.Comment: 6 pages, using emulateapj, including 2 colour figures, accepted for
publication in ApJ Letter
âAll the worldâs a stageâ: A GIS framework for recreating personal time-space from qualitative and quantitative sources
This article presents a methodological model for the study of the spaceâtime patterns of everyday life. The framework utilizes a wide range of qualitative and quantitative sources to create two environmental stages, social and built, which place and contextualize the daily mobilities of individuals as they traverse urban environments. Additionally, this study outlines a procedure to fully integrate narrative sources in a GIS. By placing qualitative sources, such as narratives, within a stageâbased GIS, researchers can begin to tell rich spatial stories about the lived experiences of segregation, social interaction, and environmental exposure. The article concludes with a case study utilizing the diary of a postal clerk to outline the wide applicability of this model for spaceâtime GIS research
Examining the Social and Built Environment Factors Influencing Childrenâs Independent Use of Their Neighborhoods and the Experience of Local Settings as Child-Friendly
Neighborhoods have traditionally served as important settings for childrenâs independent activities, but use has declined dramatically. Global positioning system (GPS) monitors, activity diaries, annotated maps, and Google Earthâenabled interviews captured the neighborhood perceptions, usage, and independent activity ranges of twenty-three children (nine to twelve years) from London, Canada. While few participants used neighborhood settings on a habitual basis, local parks and homes of nearby friends were important independent destinations. Usage was strongly influenced by positive and negative social conditions, but local environments did not generally cater well to the shifting interests of resident children. Embedding child-friendly affordances through neighborhood planning may improve childrenâs experience and independent use of local settings
Privacy and Confidentiality Issues in Historical Health Sciences Collections
Historical health sciences collections are rare and unique materials containing large amounts of information subject to confidentiality and privacy laws and concerns. Formerly, the custodians of these collections handled these issues in relative obscurity, but technological changes and changing laws and norms around health care privacy have made these issues more acute and public.
The intent of this Article is to describe the nature of these collections and the qualifications of the people who administer them, and to analyze some of the privacy and confidentiality issues that arise in the course of that work. The aim is to acquaint privacy officers, in-house legal counsel, and other members of the legal profession with the privacy and confidentiality challenges that these collections present, with the needs of researchers who use these collections, and with the reasons why historical health sciences collections are important.Publisher allows immediate open acces
Unevenly-sampled signals: a general formalism of the Lomb-Scargle periodogram
The periodogram is a popular tool that tests whether a signal consists only
of noise or if it also includes other components. The main issue of this method
is to define a critical detection threshold that allows identification of a
component other than noise, when a peak in the periodogram exceeds it. In the
case of signals sampled on a regular time grid, determination of such a
threshold is relatively simple. When the sampling is uneven, however, things
are more complicated. The most popular solution in this case is to use the
"Lomb-Scargle" periodogram, but this method can be used only when the noise is
the realization of a zero-mean, white (i.e. flat-spectrum) random process. In
this paper, we present a general formalism based on matrix algebra, which
permits analysis of the statistical properties of a periodogram independently
of the characteristics of noise (e.g. colored and/or non-stationary), as well
as the characteristics of sampling.Comment: 10 pages, 11 figures, Astronomy and Astrophysics, in pres
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