5,914 research outputs found
Data analysis and software support for the Earth radiation budget experiment
Computer programming and data analysis efforts were performed in support of the Earth Radiation Budget Experiment (ERBE) at NASA/Langley. A brief description of the ERBE followed by sections describing software development and data analysis for both prelaunch and postlaunch instrument data are presented
HALOE test and evaluation software
Computer programming, system development and analysis efforts during this contract were carried out in support of the Halogen Occultation Experiment (HALOE) at NASA/Langley. Support in the major areas of data acquisition and monitoring, data reduction and system development are described along with a brief explanation of the HALOE project. Documented listings of major software are located in the appendix
Class size, pupil attentiveness and peer relations
BACKGROUND: Despite a long-running debate over the effects of class size differences on educational performance there is little evidence on the classroom processes that might be involved. AIMS: The effects of class size differences are examined in relation to social and behavioural adjustment to school, in terms of two dimensions: attentiveness and peer relations. It was predicted that as class size increased there would be more inattentiveness in class and more signs of social difficulties between children in the form of more rejection, asocial, anxious and aggressive behaviour, and less prosocial behaviour. SAMPLES: Data came from a large-scale longitudinal study of children over KS1 (4-7 years). The observation study was based on a subsample of 235 children in 21 small (average 19 children) and 18 large (average 33 children) reception classes (aged 5 years). The PBR sample involved over 5,000. METHODS: There were two complementary methods of data collection: first, a systematic observation study of pre-selected target children in terms of three 'social modes' - when with their teachers, other children and when not interacting - and in terms of work, procedural, social and off-task activities; and, second, a teacher administered Pupil Behaviour Rating (PBR) scale comprising over 50 items rated on a 3-point scale grouped into six 'factors': hyperactive/distractible, aggressive, anxious/ fearful, prosocial, asocial, and excluded. RESULTS: Observations showed that children in large classes were more likely to show off-task behaviour of all kinds, and more likely to interact with their peers in terms of off-task behaviour, social, and also on-task behaviours. Connections between class size and PBR factors were not strong. There was no support for the view that peer relations are better in smaller classes; indeed, there was a slight tendency for worse peer relations, in terms of aggression, asocial and excluded, in the smallest classes. CONCLUSIONS: There was confirmation that children in large classes are more distracted from work and more often off task. The unexpected result, based on teacher ratings, that small classes may lead to less social and more aggressive relations between children is discussed, along with implications for teachers of a tendency for more peer-related contacts in large classes
Relationships between class size and teaching: a multi-method analysis of English infant schools
Research and debate on class size differences has focused on relations with achievement, and there is little relevant research on what mediating classroom processes might be involved. In this article we investigate connections between class size and teaching interactions. We adopt a multimethod approach, integrating qualitative in formation from teachers' end-of-year accounts and data from case studies with quantitative information from time-allocation estimates and systematic observations. Our data come from a longitudinal study of two cohorts of more than 10,000 children altogether for 3 years after enrollment in English infant schools (aged 4-7 years). Our results show, overall, that in smaller classes there is more individualized teacher support for learning. We interpret the results in the context of teacher time allocation, research on effective teaching, and post-Vygotskian approaches to teaching. It is suggested that direct models of teacher influences on pupils need to be adapted to allow for class size as a contextual factor that influences both teachers and pupils
Angular-planar CMB power spectrum
Gaussianity and statistical isotropy of the Universe are modern cosmology's
minimal set of hypotheses. In this work we introduce a new statistical test to
detect observational deviations from this minimal set. By defining the
temperature correlation function over the whole celestial sphere, we are able
to independently quantify both angular and planar dependence (modulations) of
the CMB temperature power spectrum over different slices of this sphere. Given
that planar dependence leads to further modulations of the usual angular power
spectrum , this test can potentially reveal richer structures in the
morphology of the primordial temperature field. We have also constructed an
unbiased estimator for this angular-planar power spectrum which naturally
generalizes the estimator for the usual 's. With the help of a chi-square
analysis, we have used this estimator to search for observational deviations of
statistical isotropy in WMAP's 5 year release data set (ILC5), where we found
only slight anomalies on the angular scales and . Since this
angular-planar statistic is model-independent, it is ideal to employ in
searches of statistical anisotropy (e.g., contaminations from the galactic
plane) and to characterize non-Gaussianities.Comment: Replaced to match the published version. Journal-ref: Phys.Rev. D80
063525 (2009
Imaginary in all directions: an elegant formulation of special relativity and classical electrodynamics
A suitable parameterization of space-time in terms of one complex and three
quaternionic imaginary units allows Lorentz transformations to be implemented
as multiplication by complex-quaternionic numbers rather than matrices.
Maxwell's equations reduce to a single equation.Comment: 8 page
Mopping up the Mess: A Call to Adopt the Seventh Circuitâs Standard for Assessing Comparator Evidence in Title VII Discrimination Claims
In McDonnell Douglas Corp. v. Green, the U.S. SupremeCourt developed a framework to assist courts in assessingindividual disparate treatment claims based oncircumstantial evidence. Under that test, plaintiffs allegingdiscrimination under Title VII must first show a prima faciecase of discrimination. Since McDonnell Douglas, courts havemodified the test by requiring plaintiffs to demonstrate thatthey were treated less favorably than a similarly situatedcomparator employee who is outside the plaintiffâs protectedclass. Courts disagree, however, on what it means foremployees to be similarly situated. Some courts strictlyinterpret the similarly situated requirement; others cautionagainst an overly mechanical approach and employ a flexiblestandard instead. As a result, a plaintiff could successfullyplead a prima facie case of discrimination in one federalcircuit but fail in another. To resolve this disparity, this Noteproposes that the U.S. Supreme Court adopt the SeventhCircuitâs standard for comparator evidence due to itsconsistency with the Courtâs precedent, its cohesion with thepurposes underlying Title VII, and its practical benefits forplaintiffs alleging a prima facie case of employmentdiscrimination
The impact of a social support process on alcoholics\u27 communication patterns a collaborative inquiry.
Source: Masters Abstracts International, Volume: 40-07, page: . Thesis (M.A.)--University of Windsor (Canada), 1989
Hypergraphic LP Relaxations for Steiner Trees
We investigate hypergraphic LP relaxations for the Steiner tree problem,
primarily the partition LP relaxation introduced by Koenemann et al. [Math.
Programming, 2009]. Specifically, we are interested in proving upper bounds on
the integrality gap of this LP, and studying its relation to other linear
relaxations. Our results are the following. Structural results: We extend the
technique of uncrossing, usually applied to families of sets, to families of
partitions. As a consequence we show that any basic feasible solution to the
partition LP formulation has sparse support. Although the number of variables
could be exponential, the number of positive variables is at most the number of
terminals. Relations with other relaxations: We show the equivalence of the
partition LP relaxation with other known hypergraphic relaxations. We also show
that these hypergraphic relaxations are equivalent to the well studied
bidirected cut relaxation, if the instance is quasibipartite. Integrality gap
upper bounds: We show an upper bound of sqrt(3) ~ 1.729 on the integrality gap
of these hypergraph relaxations in general graphs. In the special case of
uniformly quasibipartite instances, we show an improved upper bound of 73/60 ~
1.216. By our equivalence theorem, the latter result implies an improved upper
bound for the bidirected cut relaxation as well.Comment: Revised full version; a shorter version will appear at IPCO 2010
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