6,230 research outputs found

    Implementing quantum logic gates with GRAPE: principles and practicalities

    Full text link
    We briefly describe the use of GRAPE pulses to implement quantum logic gates in NMR quantum computers, and discuss a range of simple extensions to the core technique. We then consider a range of difficulties which can arise in practical implementations of GRAPE sequences, reflecting non-idealities in the experimental systems used.Comment: 15 pages rspublic including 4 figures. This is the original manuscript preprint form which differs slightly from the final accepted version (Phil Trans Roy Soc A in press

    Phylogeny and systematics of the giant rhinoceros beetles (Scarabaeidae: Dynastini)

    Get PDF
    This report contains the first inclusive phylogenetic analysis and taxonomic structure for the genera presently included within the scarabaeid tribe Dynastini. The study was based upon morphological, biogeographic and molecular data and yielded direct support for the recognition of three subtribes in the Dynastini: Dynastina MacLeay, New Status (Dynastes Kirby, Augosoma Burmeister, Megasoma Kirby, Golofa Hope), Xylotrupina Hope, New Status (Xylotrupes Hope, Allomyrina Arrow, Trypoxylus Minck, Xyloscaptes Prell) and Chalcosomina Rowland and Miller, New Subtribe (Chalcosoma Hope, Haploscapanes Arrow, Beckius Dechambre, Eupatorus Burmeister, Pachyoryctes Arrow). The results provide indirect but significant support for the origin of the tribe Dynastini to be of an age no later than the early Late Cretaceous. Molecular and morphological evidence suggests that Eupatorus as constituted in current taxonomic literature is not monophyletic, and taxonomic alternatives are discussed to address this deficiency. A plausible explanation is also provided for the perplexing use by F. W. Hope of the family-group names Xylotrupidae and Dynastidae

    Apparatus for ejection of an instrument cover

    Get PDF
    Apparatus for ejecting covers of instrument packages using differential pressure principl

    A Response Surface Methodology Approach to Groundwater Model Calibration

    Get PDF
    This thesis examined the effect of parameter bounding, a reduced data set, and data enrichment techniques on a response surface methodology (RSM) approach to groundwater model calibration. The four phases of the study included a calibration using a very dense data matrix, a calibration using a sparse calibration matrix, an evaluation of several data enrichment techniques, and a calibration using a data matrix enlarged with the use of the best enrichment technique. All calibrations were conducted using only a first order approximation to the response surface and with bounds placed on the input parameters. The first two calibrations using the dense and sparse data sets produced calibrated models which were very similar and very accurate. This led to the conclusion that reducing the size of the data set did not seriously degrade the calibration. The third calibration produced using the enriched data set produced results which were not as accurate as the first two calibrations and it required more calculations. Also, it was discovered that the use of a screening design would eliminate influential model parameters. All of the calibration methods provided accurate hydraulic head values, and final parameter values which were feasible

    Endocrine disrupting effects on the nesting behaviour of male three-spined stickleback Gasterosteus aculeatus L

    Get PDF
    The analysis of patterns of temporal variability in the nesting behaviour of male threespined stickleback (Gasterosteus aculeatus) exposed to the synthetic oestrogen, 17β-ethinylestradiol, revealed immediate, but transient, treatment-related effects. Gluing frequency and time spent near nest were significantly reduced in exposed fish at the beginning of the experiment. The expression of these behaviours subsequently recovered and there was no effect of treatment on nest building success. The potential causes and implications of these findings are discussed

    Are overweight children more likely to be overweight adults?

    Get PDF
    Overweight at any age in childhood increases the risk for overweight in adulthood. The relative risk (RR) ranges from 1.9 to 10.1 and increases as children get older. Not all overweight children become overweight adults, however (strength of recommendation: A, systematic review of consistent prospective and retrospective cohort studies)

    Study of a signal processor employing a synthetic phase isolator

    Get PDF
    Evaluation of signal data processor employing synthetic phase isolator techniqu

    Parametric Trajectory Representations for Behaviour Classification

    Get PDF
    This paper presents an empirical comparison of strategies for representing motion trajectories with fixed-length vectors. We compare four techniques, which have all previously been adopted in the trajectory classification literature: least-squares cubic spline approximation, the Discrete Fourier Transform, Chebyshev polynomial approximation, and the Haar wavelet transform. We measure the class separability of five different trajectory datasets- ranging from vehicle trajectories to pen trajectories- when described in terms of these representations. Results obtained over a range of dimensionalities indicate that the different representations yield similar levels of class separability, with marginal improvements provided by Chebyshev and Spline representations. For the datasets considered here, each representation appears to yield better results when used in conjunction with a curve parametrisation strategy based on arc-length, rather than time. However, we illustrate a situation- pertinent to surveillance applications- where the converse is true
    corecore