29,935 research outputs found

    Leaping and Accelerometry: A Theoretical Approach

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    Accelerometry has always been a popular method of monitoring locomotor activity but its use is becoming more widespread due to the easy availability of low cost, low power sensors. However one of the major problems with interpreting accelerometer data is that rotation of the sensor alters the output and obtaining independent orientation information is currently difficult. For the specific case of leaping locomotion full orientation information is unecessary as long as an independent measure of height change is available such as can be obtained from a sensitive pressure sensor. Therefore a 4 channel logging system recording 3 accelerometry axes combined with a channel measuring pressure could be used to accurately assess leaping locomotion. This approach should also work for any locomotion where acceleration is limited to the vertical plane but in practice it may be restricted by the sensitivity and acquisition characteristics of the pressure measurement system. Ultimately it should be a useful addition to the range of measurements available for remote locomotor monitoring particularly for leaping species such as lemurs and other non-human primates

    Analysis of planetary evolution with emphasis on differentiation and dynamics

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    In order to address the early stages of nebula evolution, a three-dimensional collapse code which includes not only hydrodynamics and radiative transfer, but also the effects of ionization and, possibly, magnetic fields is being addressed. As part of the examination of solar system evolution, an N-body code was developed which describes the latter stages of planet formation from the accretion of planetesimals. To test the code for accuracy and run-time efficiency, and to develop a stronger theoretical foundation, problems were studied in orbital dynamics. A regional analysis of the correlation in the gravity and topography fields of Venus was performed in order to determine the small and intermediate scale subsurface structure

    Low cost tooling material and process for graphite and Kevlar composites

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    An Extruded Sheet Tooling Compound (ESTC) was developed for use in quickly building low cost molds for fabricating composites. The ESTC is a very highly mineral-filled resin system formed into a 6 mm thick sheet. The sheet is laid on the pattern, vacuum (bag) is applied to remove air from the pattern surface, and the assembly is heat cured. The formed ESTC is then backed and/or framed and ready for use. The cured ESTC exhibits low coefficient of thermal expansion and maintains strength at temperatures of 180 to 200 C. Tools were made and used successfully for: Compression molding of high strength epoxy sheet molding compound, stamping of aluminum, resin transfer molding of polyester, and liquid resin molding of polyester. Several variations of ESTC can be made for specific requirements. Higher thermal conductivity can be achieved by using an aluminum particle filler. Room temperature gel is possible to allow use of foam patterns

    Equivalence of the Beta-function of the Variational Approach to that of QCD

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    The variational ansatz for the ground state wavefunctional of QCD is found to capture the anti-screening behaviour that contributes the dominant `-4' to the beta-function and leads to asymptotic freedom. By considering an SU(N) purely gauge theory in the Hamiltonian formalism and choosing the Coulomb gauge, the origins of all screening and anti-screening contributions in gluon processes are found in terms of the physical degrees of freedom. The overwhelming anti- screening contribution of `-4' is seen to originate in the renormalisation of a Coulomb interaction by a transverse gluon. The lesser screening contribution of `1/3' is seen to originate in processes involving transverse gluon interactions. It is thus apparent how the variational ansatz must be developed to capture the full running of the QCD coupling constant.Comment: 35 pages, 11 figures, LaTe

    Global Capitalism Theory and the Emergence of the Transnational Elites

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    The class and social structure of developing nations has undergone profound transformation in recent decades as each nation has incorporated into an increasingly integrated global production and financial system. National elites have experienced a new fractionation. Emergent transnationally-oriented elites grounded in globalized circuits of accumulation compete with older nationally-oriented elites grounded in more protected and often state-guided national and regional circuits. This essay focuses on structural analysis of the distinction between these two fractions of the elite and the implications for development. I suggest that nationally-oriented elites are often dependent on the social reproduction of at least a portion of the popular and working classes for the reproduction of their own status, and therefore on local development processes however so defined whereas transnationally-oriented elites are less dependent on such local social reproduction. The shift in dominant power relations from nationally- to transnationally-oriented elites is reflected in a concomitant shift to a discourse from one that defines development as national industrialization and expanded consumption to one that defines it in terms of global market integration.Elites, development, globalization, transnational, capitalism, crisis

    Digital phase-lock loop having an estimator and predictor of error

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    A digital phase-lock loop (DPLL) which generates a signal with a phase that approximates the phase of a received signal with a linear estimator. The effect of a complication associated with non-zero transport delays related to DPLL mechanization is then compensated by a predictor. The estimator provides recursive estimates of phase, frequency, and higher order derivatives, while the predictor compensates for transport lag inherent in the loop

    GRAINS AND OILSEEDS OUTLOOK FOR 2004

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    Crop Production/Industries,
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