1,734 research outputs found

    Cathode Ray Tube Display with Cancellation of Electric Field Emissions

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    A cathode ray tube display having reduced electric field emissions comprising a cathode ray tube 100, an element 200 for detecting modulations in the final anode voltage of the CRT, the signal not being directly dependent on the deflection driving means 115. A matching network 205 provides phase and gain correction to the signal from element 200, amplification means 210 receives the signal from network 205 and an emission means 215 radiates a cancelling electric field dependent on the modulations detected by said element 200

    More than Simple Psalm-Singing in English: Sacred Music in Early Colonial America

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    Histories of American sacred music frequently begin with the pilgrims’ arrival in Plymouth, bringing with them their Ainsworth’s psalter, published in Amsterdam. In subsequent decades other English-speaking colonists brought with them copies of the Sternhold and Hopkins psalter published in London. But both these psalters were increasingly deemed unsatisfactory for English-speaking colonial life, so the attempt was made to create a new American psalter, the so-called Bay Psalm Book published in Cambridge, Mass., in 1640, which in later editions morphed into what was called the New England Psalm Book. Thus English colonialism and its distinctive New England psalmody is frequently the focus of attention. But Central and North America had other colonies, some of which had been settled in the century before the English colonists arrived, colonies in which sacred music was more diverse and more developed and associated with different European languages: New Spain, New France (in the north and Huguenots in Florida), New Netherland, and New Sweden. The sacred music of these colonists is explored in this article, showing that singing the substance of religion and life was a common experience in all the these pioneer colonies, whether it was expressed in Latin, Spanish, French, Dutch, Swedish, as well as English. Music was the vehicle of faith, personal and public, that was far more diverse and rich than the simple English psalm-singing that is often portrayed as the essence and substance of early American colonial religious music

    Stochastic arrays and learning networks

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    This thesis presents a study of stochastic arrays and learning networks. These arrays will be shown to consist of simple elements utilising probabilistic coding techniques which may interact with a random and noisy environment to produce useful results. Such networks have generated considerable interest since it is possible to design large parallel self-organising arrays of these elements which are trained by example rather than explicit instruction. Once the learning process has been completed, they then have the potential ability to form generalisations, perform global optimisation of traditionally difficult problems such as routing and incorporate an associative memory capability which can enable such tasks as image recognition and reconstruction to be performed, even when given a partial or noisy view of the target. Since the method of operation of such elements is thought to emulate the basic properties of the neurons of the brain, these arrays have been termed neural 'networks. The research demonstrates the use of stochastic elements for digital signal processing by presenting a novel systolic array, utilising a simple, replicated cell structure, which is shown to perform the operations of Cyclic Correlation and the Discrete Fourier Transform on inherently random and noisy probabilistic single bit inputs. This work is then extended into the field of stochastic learning automata and to neural networks by examining the Associative Reward-Punish (A(_R-P)) pattern recognising learning automaton. The thesis concludes that all the networks described may potentially be generalised to simple variations of one standard probabilistic element utilising stochastic coding, whose properties resemble those of biological neurons. A novel study is presented which describes how a powerful deterministic algorithm, previously considered to be biologically unviable due to its nature, may be represented in this way. It is expected that combinations of these methods may lead to a series of useful hybrid techniques for training networks. The nature of the element generalisation is particularly important as it reveals the potential for encoding successful algorithms in cheap, simple hardware with single bit interconnections. No claim is made that the particular algorithms described are those actually utilised by the brain, only to demonstrate that those properties observed of biological neurons are capable of endowing collective computational ability and that actual biological algorithms may perhaps then become apparent when viewed in this light

    Editorial

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    Continuous phase transition in polydisperse hard-sphere mixture

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    In a previous paper (J. Zhang {\it et al.}, J. Chem. Phys. {\bf 110}, 5318 (1999)) we introduced a model for polydisperse hard sphere mixtures that is able to adjust its particle-size distribution. Here we give the explanation of the questions that arose in the previous description and present a consistent theory of the phase transition in this system, based on the Percus-Yevick equation of state. The transition is continuous, and like Bose-Einstein condensation a macroscopic aggregate is formed due to the microscopic interactions. A BMCSL-like treatment leads to the same conclusion with slightly more accurate predictions.Comment: 7 pages including 5 figures in revte

    Financial engineering and the productivity crisis

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    Quasi-Normal Modes of Brane-Localised Standard Model Fields II: Kerr Black Holes

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    This paper presents a comprehensive study of the fundamental quasinormal modes of all Standard Model fields propagating on a brane embedded in a higher-dimensional rotating black hole spacetime. The equations of motion for fields with spin s=0,1/2s=0, 1/2 and 1 propagating in the induced-on-the-brane background are solved numerically, and the dependence of their QN spectra on the black hole angular momentum and dimensionality of spacetime is investigated. It is found that the brane-localised field perturbations are longer-lived when the higher-dimensional black hole rotates faster, while an increase in the number of transverse-to-the-brane dimensions reduces their lifetime. Finally, the quality factor QQ, that determines the best oscillator among the different field perturbations, is investigated and found to depend on properties of both the particular field studied (spin, multipole numbers) and the gravitational background (dimensionality, black hole angular momentum number).Comment: 12 pages, 8 figures, typos corrected, version to appear in Phys. Rev.
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