1,035 research outputs found

    Analysis of Sting Balance Calibration Data Using Optimized Regression Models

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    Calibration data of a wind tunnel sting balance was processed using a search algorithm that identifies an optimized regression model for the data analysis. The selected sting balance had two moment gages that were mounted forward and aft of the balance moment center. The difference and the sum of the two gage outputs were fitted in the least squares sense using the normal force and the pitching moment at the balance moment center as independent variables. The regression model search algorithm predicted that the difference of the gage outputs should be modeled using the intercept and the normal force. The sum of the two gage outputs, on the other hand, should be modeled using the intercept, the pitching moment, and the square of the pitching moment. Equations of the deflection of a cantilever beam are used to show that the search algorithm s two recommended math models can also be obtained after performing a rigorous theoretical analysis of the deflection of the sting balance under load. The analysis of the sting balance calibration data set is a rare example of a situation when regression models of balance calibration data can directly be derived from first principles of physics and engineering. In addition, it is interesting to see that the search algorithm recommended the same regression models for the data analysis using only a set of statistical quality metrics

    Body Positions Used by Healthy and Frail Older Adults to Rise from the Floor

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111270/1/j.1532-5415.2000.tb03874.x.pd

    Rising from the Floor in Older Adults

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/111267/1/j.1532-5415.1997.tb03088.x.pd

    Functional architecture of olfactory ionotropic glutamate receptors.

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    Ionotropic glutamate receptors (iGluRs) are ligand-gated ion channels that mediate chemical communication between neurons at synapses. A variant iGluR subfamily, the Ionotropic Receptors (IRs), was recently proposed to detect environmental volatile chemicals in olfactory cilia. Here, we elucidate how these peripheral chemosensors have evolved mechanistically from their iGluR ancestors. Using a Drosophila model, we demonstrate that IRs act in combinations of up to three subunits, comprising individual odor-specific receptors and one or two broadly expressed coreceptors. Heteromeric IR complex formation is necessary and sufficient for trafficking to cilia and mediating odor-evoked electrophysiological responses in vivo and in vitro. IRs display heterogeneous ion conduction specificities related to their variable pore sequences, and divergent ligand-binding domains function in odor recognition and cilia localization. Our results provide insights into the conserved and distinct architecture of these olfactory and synaptic ion channels and offer perspectives into the use of IRs as genetically encoded chemical sensors. VIDEO ABSTRACT

    Proving equivalence between imperative and MapReduce implementations using program transformations

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    Distributed programs are often formulated in popular functional frameworks like MapReduce, Spark and Thrill, but writing efficient algorithms for such frameworks is usually a non-trivial task. As the costs of running faulty algorithms at scale can be severe, it is highly desirable to verify their correctness. We propose to employ existing imperative reference implementations as specifications for MapReduce implementations. To this end, we present a novel verification approach in which equivalence between an imperative and a MapReduce implementation is established by a series of program transformations. In this paper, we present how the equivalence framework can be used to prove equivalence between an imperative implementation of the PageRank algorithm and its MapReduce variant. The eight individual transformation steps are individually presented and explained
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