6,881 research outputs found

    Negative Energies and a Constantly Accelerating Flat Universe

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    It has been shown that in the context of General Relativity (GR) enriched with a new set of discrete symmetry reversal conjugate metrics, negative energy states can be rehabilitated while avoiding the well-known instability issues. We review here some cosmological implications of the model and confront them with the supernovae and CMB data. The predicted flat universe constantly accelerated expansion phase is found to be in rather good agreement with the most recent cosmological data

    Monitoring and Assessing the Use of External Quality Review Organizations to Improve Services for Young Children: A Toolkit for State Medicaid Agencies

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    Assesses the extent to which states use external quality review organizations in studying the quality of preventive and developmental services for young children enrolled in Medicaid, and provides guidance on determining their scope of work

    The Recrudescence of Property Rights as the Foremost Principle of Civil Liberties: The First Decade of the Burger Court

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    The analysis of the donor-acceptor pair luminescence of P-Al and N-Al pairs obtained recently for the cubic 3C polytype of SiC is viewed in some detail. A detailed consideration is given to the fitting procedure applied to the P-Al and N-Al spectra. Fit with theoretical models of spectra of type I and type II are applied to both N-Al and P-Al experimental spectra, and it is demonstrated that only contribution from P on Si site is observable in the presented samples. The accuracy of the obtained phosphorus ionization energy of 48.1 meV is also discussed

    Animated electronic painting

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    In this thesis I intend to explore the possibilities of interfacing the Geni-graphics Paint system with the Animation System to create the illusion of pixel based animation on a two dimensional, object based system. The imagery for the animation will be developed from my work in painting and illustration in an at tempt to create an animated electronic painting

    Weight Adjustment Methods and Their Impact on Sample-based Inference

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    Weighting samples is important to reflect not only sample design decisions made at the planning stage, but also practical issues that arise during data collection and cleaning that necessitate weighting adjustments. Adjustments to base weights are used to account for these planned and unplanned eventualities. Often these adjustments lead to variations in the survey weights from the original selection weights (i.e., the weights based solely on the sample units' probabilities of selection). Large variation in survey weights can cause inferential problems for data users. A few extremely large weights in a sample dataset can produce unreasonably large estimates of national- and domain-level estimates and their variances in particular samples, even when the estimators are unbiased over many samples. Design-based and model-based methods have been developed to adjust such extreme weights; both approaches aim to trim weights such that the overall mean square error (MSE) is lowered by decreasing the variance more than increasing the square of the bias. Design-based methods tend to be ad hoc, while Bayesian model-based methods account for population structure but can be computationally demanding. I present three research papers that expand the current weight trimming approaches under the goal of developing a broader framework that connects gaps and improves the existing alternatives. The first paper proposes more in-depth investigations of and extensions to a newly developed method called generalized design-based inference, where we condition on the realized sample and model the survey weight as a function of the response variables. This method has potential for reducing the MSE of a finite population total estimator in certain circumstances. However, there may be instances where the approach is inappropriate, so this paper includes an in-depth examination of the related theory. The second paper incorporates Bayesian prior assumptions into model-assisted penalized estimators to produce a more efficient yet robust calibration-type estimator. I also evaluate existing variance estimators for the proposed estimator. Comparisons to other estimators that are in the literature are also included. In the third paper, I develop summary- and unit-level diagnostic tools that measure the impact of variation of weights and of extreme individual weights on survey-based inference. I propose design effects to summarize the impact of variable weights produced under calibration weighting adjustments under single-stage and cluster sampling. A new diagnostic for identifying influential, individual points is also introduced in the third paper

    Current techniques of ancient textile analysis: a critical review

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    Throughout pre-history and historical times few items produced by people have been as central to daily life as textiles. Textiles have been produced in the majority of archaeological periods and in most geographic regions of the world. Their analysis thus has significant implications for the technological, cultural and social development and diversity of our ancestors. Over the last two decades unprecedented advances have taken place in the analysis of ancient textiles. It is the purpose of this study to critically examine these advances, and to assess their significance to meaningful cultural investigation. To ensure a coherent structure to the research, Scandinavian period textiles from York and Scotland are utilised. The data are particularly appropriate for this purpose as the different types of preservation, burial contexts and geographical areas in which they were found enables investigations into reactions to burial conditions and conservation techniques, as well as cultural-historical issues. When examining archaeological textiles it is necessary to have clear aims on the nature of the information required and how such information can be used. The fundamental reason for the analysis of textiles is to further an understanding of technological and culture history. To ensure optimum information is gained to facilitate cultural investigation and interpretation, an understanding of the conditions under which textiles survive and techniques of conservation is necessary. The use of appropriate analytical techniques to obtain technical details sufficient for full an accurate description of textiles is also essential. Finally, an awareness of the obstacles preventing us gaining this information is desirable. This thesis is therefore concentrated on these issues to form a base for future research

    Compliance to Dietary Guidelines in Elementary School Food Service

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    The purpose of this study was to determine compliance to the Dietary Guidelines for Americans and to Recommend Dietary Allowances in Tennessee elementary school lunch programs and to determine training practices as they are related to nutrition. Fifty six of the 145 school food service supervisors in Tennessee participated in the study, a response rate 39%. A four-part questionnaire was developed for all school food service supervisors in the state of Tennessee. The first three parts of the questionnaire consisted of items about types of food products used in cooking, the school food service supervisors\u27 participation in training, and demographic information about the supervisors. In the fourth part of the questionnaire, menus were requested from each school for comparisons with Recommended Dietary Allowances (RDA) and Dietary Guidelines. Using 1/3 of the RDA as a standard of adequacy, nutritional analysis of the menus, using Nutritionist III, showed more than adequate amounts of protein, vitamin A, vitamin C, vitamin B6, folate, sodium, magnesium, calcium, iron, and zinc. Kilocalories were adequate for elementary school aged children. Fat intake was above the 30% recommended amount of kilocalories, fat represented 35.7% in this study. Sodium intake was 1000.9 ± 492.1 mg. The study identified that some of the barriers to implementing the Dietary Guidelines were financial constraints, high saturated fat content of government commodities, lack of support for training, and lack of classroom nutrition education in the schools
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