2,460 research outputs found

    Short arc reduction of radar altimetry computer program

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    The Air Force Geophysics Laboratory computer program SARRA (Short Arc Reduction of Radar Altimetry) has been used for geoid determination with altimetric observations from the GEOS-3 satellite. An important feature of SARRA is the simultaneous recovery of the orbit parameters and the surface coefficients as defined by covariance function weights. Orbits good to approximately 20 meters are adequate for precise geoid determinations by virtue of the orbital adjustment in the reductions. Altimetric data over a portion of the North Atlantic Ocean have been processed to derive the regional geoid and gravity field. Analyses of altimeter residuals resulting from the short arc adjustment show that the residuals can be used to define the neglected higher order geoidal undulations with high fidelity and continuity

    Relatively free bands of groups

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    Tree-width and dimension

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    Over the last 30 years, researchers have investigated connections between dimension for posets and planarity for graphs. Here we extend this line of research to the structural graph theory parameter tree-width by proving that the dimension of a finite poset is bounded in terms of its height and the tree-width of its cover graph.Comment: Updates on solutions of problems and on bibliograph

    Sulfur amino acid requirement of the growing pig

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    A growth trial and a nitrogen retention trial were conducted to determine the sulfur amino acid requirement of the growing pig. Adding 0.10% DL-methionine to a 14.1% protein basal diet containing 0.21% sulfur amino acids significantly (P\u3c.05) increased daily gain and nitrogen retention. Further additions gave no beneficial effect, indicating that the sulfur amino acid requirement had been met by the initial addition of DL-methionine. Thus, the sulfur amino acid requirement of the growing pig fed a 14.1% protein diet does not exceed 0.31% of the diet.; Swine Day, Manhattan, KS, November 14, 197

    Structure and optical properties of high light output halide scintillators

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    Structural and optical properties of several high light output halide scintillators and closely related materials are presented based on first principles calculations. The optical properties are based on the Engel-Vosko generalized gradient approximation and the recently developed density functional of Tran and Blaha. The materials investigated are BaBr2_2, BaIBr, BaCl2_2, BaF2_2, BaI2_2, BiI3_3, CaI2_2, Cs2LiYCl_2LiYCl_6,CsBa, CsBa_2BrBr_5,CsBa, CsBa_2II_5,K, K_2LaBrLaBr_5,K, K_2LaClLaCl_5,K,K_2LaILaI_5,LaBr, LaBr_3,LaCl, LaCl_3,SrBr, SrBr_2,andYI, and YI_3.ForcomparisonresultsarepresentedfortheoxideCdWO. For comparison results are presented for the oxide CdWO_4.WefindthattheTranBlahafunctionalgivesgreatlyimprovedbandgapsandopticalpropertiesinthisclassofmaterials.Furthermore,wefindthatunlikeCdWO. We find that the Tran Blaha functional gives greatly improved band gaps and optical properties in this class of materials. Furthermore, we find that unlike CdWO_4$, most of these halides are highly isotropic from an optical point of view even though in many cases the crystal structures and other properties are not. This general result is rationalized in terms of halide chemistry. Implications for the development of ceramic halide scintillators are discussed

    Exploring the Variation in Spatial Landscape Utilisation by Cows in the Pre- and Post-Partum Period Using GNSS Technology

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    On-animal sensors refer to systems that monitor the location, behaviour, or physiological characteristics of livestock. These technologies provide a method to overcome many of the challenges that are associated with monitoring livestock within an extensive grazing system. A global navigation satellite system (GNSS) could be used to detect the changes in spatial utilisation associated with when a cow has a calf at foot. In this study, forty pregnant Belmont Red heifers were fitted with GNSS collars programmed to provide a location reading at 5 minute intervals. The data was cleaned and mapped in ArcGIS to identify changes in paddock area preference in the week prior to (-7d to -1d) and following (1d to 7d) parturition. A total of 14 heifers calved during this period and an overall reduction in the total area utilised was observed following parturition. Ten animals showed a preference for the eastern-side of the paddock following calving. These results suggest that paddock utilisation by cows does change around parturition but is inconsistent. Further research is required to better understand this issue, however, this information could be used to inform management decisions around resource distribution in the post-partum period to maximise productivity and animal welfare

    Neutron-proton analyzing power at 12 MeV and inconsistencies in parametrizations of nucleon-nucleon data

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    We present the most accurate and complete data set for the analyzing power Ay(theta) in neutron-proton scattering. The experimental data were corrected for the effects of multiple scattering, both in the center detector and in the neutron detectors. The final data at En = 12.0 MeV deviate considerably from the predictions of nucleon-nucleon phase-shift analyses and potential models. The impact of the new data on the value of the charged pion-nucleon coupling constant is discussed in a model study.Comment: Six pages, four figures, one table, to be published in Physics Letters

    Experimental implementation of an adiabatic quantum optimization algorithm

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    We report the realization of a nuclear magnetic resonance computer with three quantum bits that simulates an adiabatic quantum optimization algorithm. Adiabatic quantum algorithms offer new insight into how quantum resources can be used to solve hard problems. This experiment uses a particularly well suited three quantum bit molecule and was made possible by introducing a technique that encodes general instances of the given optimization problem into an easily applicable Hamiltonian. Our results indicate an optimal run time of the adiabatic algorithm that agrees well with the prediction of a simple decoherence model.Comment: REVTeX, 5 pages, 4 figures, improved lay-out; accepted for publication in Physical Review Letter

    Listening and learning : the reciprocal relationship between worker and client

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    The relationship between worker and client has for the best part of 100 years been the mainstay of probation, and yet has recently been eroded by an increased emphasis on punishment, blame and managerialism. The views of offenders are in direct contradiction to these developments within the criminal justice system and this article argues that only by taking account of the views of those at the 'coal face' will criminologists, policy makers and practitioners be able to effect real change in crime rates. The article thus focuses on the views of a sample of previously persistent offenders in Scotland about offending, desistance and how the system can help them. It explores not only their need for friendship and support in youth but also the close association between relationships and the likelihood of offending. It also demonstrates the views of offenders themselves about the importance of the working relationship with supervising officers in helping them desist from crime. The article concludes that the most effective way of reducing offending is to re-engage with the message of the Probation Act of 100 years ago, namely, to 'advise, assist and befriend' offenders rather than to 'confront, challenge and change' offending behaviour

    Moderate deviations for the determinant of Wigner matrices

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    We establish a moderate deviations principle (MDP) for the log-determinant log⁥∣det⁥(Mn)∣\log | \det (M_n) | of a Wigner matrix MnM_n matching four moments with either the GUE or GOE ensemble. Further we establish Cram\'er--type moderate deviations and Berry-Esseen bounds for the log-determinant for the GUE and GOE ensembles as well as for non-symmetric and non-Hermitian Gaussian random matrices (Ginibre ensembles), respectively.Comment: 20 pages, one missing reference added; Limit Theorems in Probability, Statistics and Number Theory, Springer Proceedings in Mathematics and Statistics, 201
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