1,877 research outputs found

    Approach to Sounding on the VAS Processor

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    The key features of the sounding software laboratory being installed on the VAS Processor at NASA/GSFC are outlined. Emphasis is on the support data and personal guidance that a meteorological researcher must provide to attune a physically modeled VAS sounding to his experiment. The fundamental aim of the sounding-support effort is to provide a system which makes use of: radiation transfer models based upon laboratory data, analytic inversion schemes, human guidance for quality control, statistically conditioned retrieval methods, and current ancillary data

    Calculations of atmospheric transmittance in the 11 micrometer window for estimating skin temperature from VISSR infrared brightness temperatures

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    An algorithm for calculating the atmospheric transmittance in the 10 to 20 micro m spectral band from a known temperature and dewpoint profile, and then using this transmittance to estimate the surface (skin) temperature from a VISSR observation in the 11 micro m window is presented. Parameterizations are drawn from the literature for computing the molecular absorption due to the water vapor continuum, water vapor lines, and carbon dioxide lines. The FORTRAN code is documented for this application, and the sensitivity of the derived skin temperature to variations in the model's parameters is calculated. The VISSR calibration uncertainties are identified as the largest potential source of error

    A spectral filter for ESMR's sidelobe errors

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    Fourier analysis was used to remove periodic errors from a series of NIMBUS-5 electronically scanned microwave radiometer brightness temperatures. The observations were all taken from the midnight orbits over fixed sites in the Australian grasslands. The angular dependence of the data indicates calibration errors consisted of broad sidelobes and some miscalibration as a function of beam position. Even though an angular recalibration curve cannot be derived from the available data, the systematic errors can be removed with a spectral filter. The 7 day cycle in the drift of the orbit of NIMBUS-5, coupled to the look-angle biases, produces an error pattern with peaks in its power spectrum at the weekly harmonics. About plus or minus 4 K of error is removed by simply blocking the variations near two- and three-cycles-per-week

    Has the effect of parents’ education on child’s education changed over time?

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    This paper examines whether the expansion of higher education has reduced inequality by providing more opportunities for students from less privileged backgrounds to attend university or further entrenched existing inequalities. Drawing on Maximally Maintained Inequality theory and Relative Risk Aversion theory, I use logistic regressions to analyse data collected by three nationally representative, crosssectional surveys conducted between 1987 and 2005 (N= 4463) to examine the association between parents’ education and child’s education. Having a universityeducated parent is used as a proxy for membership of the privileged class based on the assumption that children of university-educated parents are more likely to take advantage of opportunities to acquire higher education. University-educated parents are also better placed to provide extra tuition and to assist their children negotiate the education system. I find that although the expansion of higher education has had some impact, having a university-educated parent continues to exert a direct effect on an individual’s propensity to graduate from university.Higher Education, Inequality, Mobility

    Film models for transport phenomena with fog formation: the classical film model

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    In the present analysis the classical film model (or film theory) is reviewed and extended. First, on the basis of a thorough analysis, the governing equations of diffusion, energy and momentum of a stagnant film are derived and solved. Subsequently, the well-known correction factors for the effect of suction/injection on mass, heat and momentum transfer are derived. Next, employing global balances of mass, energy and momentum, the film model is applied to channel flow. This application yields a new expression for the pressure drop and hence it is compared extensively with experimental and theoretical results of previous investigators, yielding good agreement. The onset of fog formation in a binary mixture, both in the transferring film and/or in the bulk, is explained graphically with the help of the relation between temperature and vapour mass fraction and the saturation line of the vapour.\ud \u

    Towards the true tree: Bioinformatic approaches in the phylogenetics and molecular evolution of the Endopterygota

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    In this thesis, I use bioinformatic approaches to address new and existing issues surrounding large-scale phylogenetic analysis. A phylogenetic analysis pipeline is developed to aid an investigation of the suitability of integrating Cytochrome Oxidase Subunit 1 (cox1) into phylogenetic supermatrices. In the first two chapters I assess the effect of varying cox1 sample size within a large variable phylogenetic context. As well as intuitive results on increased quality with greater taxon sampling, there are clear monophyly patters relating to local taxonomic sampling. Specifically, more monophyletic resampled taxa in cases when fewer consubfamilials are represented, with a tendency for these to remain unchanged in the degree of monophyly when rarefied. Sampling analyses are extended in chapter two using a mined Scarabaeoidea multilocus dataset, where taxa from given loci are used to improve existing matrices. Improvement in phylogenetic signal is best achieved by targeting cox1 to existing taxa, which suggests minimum parameters for cox1 adoption in large-scale phylogenetics. In chapter 3 I address recently-arisen issues related to phyloinformatic analysis of sequence-delineated matrices. There is ongoing work on setting species boundaries by sequence variation alone, but incongruence results in methodological issues upon integrating multiple loci delineated in this way. In the final chapter I assess the impact of heterogeneous substitution rates on large scale cox1 datasets. Although the number of heterogeneous sites in Coleoptera cox1 is substantial, their presence is found to be beneficial, as their removal negatively impacts the ability of the alignment to generate the 'known' topology. The homoplasy and heterogeneous characteristics of cox1 have not substantially impacted its utility, thus the cox1 datasets have potential to play a substantial role in the tree-of-life

    Evidence and Perceptions of Inequality in Australia

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    Following the increasing impact of globalising economic forces world wide Australia, like many other liberal democracies, moved to adopt neoliberal economic policies with an emphasis on increasing deregulation of economic markets. The economic changes instituted since the 1980s have fundamentally restructured the economy and created a more flexible labour market. Jobs growth has been concentrated in industries that rely heavily on casual and part-time workers. Consequently, the proportion of all jobs that are permanent and full-time has declined. In this paper, we are interested in how these changes have affected the level of income and wealth inequality within Australian society. Although there is a general agreement amongst researchers that there has not been a significant increase in inequality in regard to either income or wealth between the 1980s and the 2000s, some researchers argue that earnings inequality has increased. There is also evidence of a mismatch between objective measures of inequality and the perceptions of the Australian people, with a significant majority of respondents in a national survey conducted in 2005 believing that Australia had become a more divided and less fair society since the 1980s. The present paper examines these disparities and attempts to account for them.Social inequality, neoliberalism, attitudes

    Matchsticks Design & Memory: a ‘culture fair’ test of visuo-spatial learning & memory

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    Objectives: Clinical neuropsychologists are increasingly called upon to undertake cognitive assessment of clients from diverse cultures, with limited educational opportunity. The Matchstick Design & Memory test is intended to provide a culture-fair visual test of learning and memory, that does not depend on writing or drawing skills. Design/Methods: In study 1, a group of community-dwelling Sylheti-Bengali older-adults were asked to complete the standard format Rey-Osterrieth Complex Figure Test. The scores for the copy, immediate recall, and delayed recall trials were all well-below expected, and many of the participants declined to provide a drawing. In study 2, a group of community-dwelling Sylheti-Bengali older-adults were asked to complete the new Matchstick Design & Memory test. The scores for the copy, immediate recall, and delayed recall trials suggested good reproduction and memory for the design, and all participants engaged with the task. In study 3, preliminary clinical data suggests that Sylheti-Bengali older-adults with a diagnosis of dementia scored well below their community dwelling peers for immediate and delayed recall on the matchsticks test. Discussion: The Matchstick Design & Memory test appears to be a useful new test of visual learning and memory, that utilises familiar, low-cost materials, and does not depend on writing or drawing skills. Future research on the test’s reliability and validity is needed, as well as substantive norms for specific cultural/linguistic groups. The properties of the test may also make it useful for remote administration (e.g., video-based cognitive assessment)

    Performance appraisal of VAS radiometry for GOES-4, -5 and -6

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    The first three VISSR Atmospheric Sounders (VAS) were launched on GOES-4, -5, and -6 in 1980, 1981 and 1983. Postlaunch radiometric performance is assessed for noise, biases, registration and reliability, with special attention to calibration and problems in the data processing chain. The postlaunch performance of the VAS radiometer meets its prelaunch design specifications, particularly those related to image formation and noise reduction. The best instrument is carried on GOES-5, currently operational as GOES-EAST. Single sample noise is lower than expected, especially for the small longwave and large shortwave detectors. Detector to detector offsets are correctable to within the resolution limits of the instrument. Truncation, zero point and droop errors are insignificant. Absolute calibration errors, estimated from HIRS and from radiation transfer calculations, indicate moderate, but stable biases. Relative calibration errors from scanline to scanline are noticeable, but meet sounding requirements for temporarily and spatially averaged sounding fields of view. The VAS instrument is a potentially useful radiometer for mesoscale sounding operations. Image quality is very good. Soundings derived from quality controlled data meet prelaunch requirements when calculated with noise and bias resistant algorithms
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