3,814 research outputs found
Language and Speech Predictors of Reading Achievement in Preschool Children with Language Disorders
ABSTRACT LANGUAGE AND SPEECH PREDICTORS OF READING ACHIEVEMENT IN PRESCHOOL CHILDREN WITH LANGUAGE DISORDERS by Juliet K. Haarbauer-Krupa The purpose of this longitudinal study was to examine the relationship between language and reading in children diagnosed with developmental language disorder (DLD) during preschool. An archival data set was available for analysis. Preschool children with DLD who were assessed between 35 and 74 months for preschool language and speech abilities (Rapin, 1996) returned for language, speech and reading testing at age seven years. Children who enrolled in the study were a clinically referred sample, met criteria for average nonverbal intellectual functioning, and demonstrated below average performance on a composite language measure. To evaluate a hypothesis about the contribution of vocabulary, grammar, and speech articulation to reading outcome measures, a series of regression analyses tested models to identify predictors of reading achievement at age seven. Results indicated a strong, positive relationship between language skills assessed at both ages and reading comprehension. School-age language and speech skills explained 25% of the variance in reading comprehension after controlling for word identification skills. Grammar at school age was a significant unique predictor of reading comprehension. Preschool language and speech skills explained 22% of the variance after controlling for word identification skills. Speech articulation was not related to reading outcomes. In contrast, regression analyses suggested that language and speech skills did not predict word reading abilities. Children who had reading comprehension difficulties had weaker vocabulary, grammar and speech skills compared to children who had average and above comprehension skills. Findings support previous research describing a relationship between language skills and reading comprehension. Language skills measured at preschool can predict reading comprehension difficulties in elementary school for children with DLD. Results highlight the importance of early identification and intervention of language impairment in children to improve areas of vocabulary and grammar critical to reading success
Machine-learning identification of galaxies in the WISExSuperCOSMOS all-sky catalogue
The two currently largest all-sky photometric datasets, WISE and SuperCOSMOS,
were cross-matched by Bilicki et al. (2016) (B16) to construct a novel
photometric redshift catalogue on 70% of the sky. Galaxies were therein
separated from stars and quasars through colour cuts, which may leave
imperfections because of mixing different source types which overlap in colour
space. The aim of the present work is to identify galaxies in the
WISExSuperCOSMOS catalogue through an alternative approach of machine learning.
This allows us to define more complex separations in the multi-colour space
than possible with simple colour cuts, and should provide more reliable source
classification. For the automatised classification we use the support vector
machines learning algorithm, employing SDSS spectroscopic sources cross-matched
with WISExSuperCOSMOS as the training and verification set. We perform a number
of tests to examine the behaviour of the classifier (completeness, purity and
accuracy) as a function of source apparent magnitude and Galactic latitude. We
then apply the classifier to the full-sky data and analyse the resulting
catalogue of candidate galaxies. We also compare thus produced dataset with the
one presented in B16. The tests indicate very high accuracy, completeness and
purity (>95%) of the classifier at the bright end, deteriorating for the
faintest sources, but still retaining acceptable levels of 85%. No significant
variation of classification quality with Galactic latitude is observed.
Application of the classifier to all-sky WISExSuperCOSMOS data gives 15 million
galaxies after masking problematic areas. The resulting sample is purer than
the one in B16, at a price of lower completeness over the sky. The automatic
classification gives a successful alternative approach to defining a reliable
galaxy sample as compared to colour cuts.Comment: 12 pages, 15 figures, accepted for publication in A&A. Obtained
catalogue will be included in the public release of the WISExSuperCOSMOS
galaxy catalogue available from http://ssa.roe.ac.uk/WISExSCO
A Novel Identity Based Blind Signature Scheme using DLP for E-Commerce
Abstract— Blind signatures are used in the most of the application where confidentiality and authenticity are the main issue. Blind signature scheme deals with concept where requester sends the request that the signer should sign on a blind message without looking at the content. Many ID based blind signature are proposed using bilinear pairings and elliptic curve. But the relative computation cost of the pairing in bilinear pairings and ID map into an elliptic curve are huge. In order to save the running time and the size of the signature, this paper proposed a scheme having the property of both concepts identity based blind signature that is based on Discrete Logarithm Problem, so as we know that DLP is a computational hard problem and hence the proposed scheme achieves all essential and secondary security prematurity. With the help of the proposed scheme, this paper implemented an E-commerce system in a secure way. E-commerce is one of the most concern applications of ID based blind signature scheme. E-commerce consisting selling and buying of products or services over the internet and open network. ID based blind signature scheme basically has been used enormously as a part of today’s focussed business. Our proposed scheme can be also be used in E-business, E-voting and E-cashing anywhere without any restriction
DOI: 10.17762/ijritcc2321-8169.15060
SALT long-slit spectroscopy of LBQS 2113-4538: variability of the Mg II and Fe II component
The Mg II line is of extreme importance in intermediate redshift quasars
since it allows us to measure the black hole mass in these sources and to use
these sources as probes of the distribution of dark energy in the Universe, as
a complementary tool to SN Ia. Reliable use of Mg II requires a good
understanding of all the systematic effects involved in the measurement of the
line properties, including the contamination by Fe II UV emission. We performed
three spectroscopic observations of a quasar LBQS 2113-4538 (z = 0.956) with
the SALT telescope separated in time by several months and we analyze in detail
the mean spectrum and the variability in the spectral shape. We show that even
in our good-quality spectra the Mg II doublet is well fit by a single
Lorentzian shape. We tested several models of the Fe II pseudo-continuum and
showed that one of them well represents all the data. The amplitudes of both
components vary in time, but the shapes do not change significantly. The
measured line width of LBQS 2113-4538 identifies this object as a class A
quasar. The upper limit of for the contribution of the Narrow Line Region
(NLR) to Mg II may suggest that the separation of the Broad Line Region (BLR)
and NLR disappears in this class of objects.Comment: 10 pages, 8 figures, accepted to A&
Interplay of Kerr and Raman beam cleaning with a multimode microstructure fiber
We experimentally study the competition between Kerr beam self-cleaning and
Raman beam cleanup in a multimode air-silica microstructure optical fiber. Kerr
beam self-cleaning of the pump is observed for a certain range of input powers
only. Raman Stokes beam generation and cleanup lead to both depletion and
degradation of beam quality for the pump. The interplay of modal four-wave
mixing and Raman scattering in the infrared domain lead to the generation of a
multimode supercontinuum ranging from 500 nm up to 1800 nm
Relaxation under outflow dynamics with random sequential updating
In this paper we compare the relaxation in several versions of the Sznajd
model (SM) with random sequential updating on the chain and square lattice. We
start by reviewing briefly all proposed one dimensional versions of SM. Next,
we compare the results obtained from Monte Carlo simulations with the mean
field results obtained by Slanina and Lavicka . Finally, we investigate the
relaxation on the square lattice and compare two generalizations of SM, one
suggested by Stauffer and another by Galam. We show that there are no
qualitative differences between these two approaches, although the relaxation
within the Galam rule is faster than within the well known Stauffer rule.Comment: 9 figure
Self-cleaning on a higher order mode in ytterbium-doped multimode fiber with parabolic profile
We experimentally demonstrate polarization-dependent Kerr spatial beam self-cleaning into the LP11 mode of an Ytterbium-doped multimode optical fiber with parabolic gain and refractive index profiles
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