4,328 research outputs found

    Visualizing Coevolution With CIAO Plots

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    In a previous paper [2], we introduced a number of visualization techniques that we had developed for monitoring the dynamics of artificial competitive co-evolutionary systems. One of these techniques involves evaluating the performance of an individual from the current population in a series of trials against opponents from all previous generations, and visualizing the results as a 2-d grid of shaded cells or pixels: qualitative patterns in the shading can indicate different classes of co-evolutionary dynamic. As this technique involves pitting a Current Individual against Ancestral Opponents, we referred to the visualizations as CIAO plots. Since then, a number of other authors studying the dynamics of competitive co-evolutionary systems have used CIAO plots or close derivatives to help illuminate the dynamics of their systems, and it has become something of a de facto standard visualization technique. In this very brief paper we summarise the rationale for CIAO plots, explain the method of constructing a CIAO plot, and review important recent results that identify significant limitations of this technique

    Dynamic Spin-Polarized Resonant Tunneling in Magnetic Tunnel Junctions

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    Precisely engineered tunnel junctions exhibit a long sought effect that occurs when the energy of the electron is comparable to the potential energy of the tunneling barrier. The resistance of metal-insulator-metal tunnel junctions oscillates with an applied voltage when electrons that tunnel directly into the barrier's conduction band interfere upon reflection at the classical turning points: the insulator-metal interface, and the dynamic point where the incident electron energy equals the potential barrier inside the insulator. A model of tunneling between free electron bands using the exact solution of the Schroedinger equation for a trapezoidal tunnel barrier qualitatively agrees with experiment.Comment: 4pgs, 3 fig

    A 275–425-GHz Tunerless Waveguide Receiver Based on AlN-Barrier SIS Technology

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    We report on a 275–425-GHz tunerless waveguide receiver with a 3.5–8-GHz IF. As the mixing element, we employ a high-current-density Nb–AlN–Nb superconducting–insulating– superconducting (SIS) tunnel junction. Thanks to the combined use of AlN-barrier SIS technology and a broad bandwidth waveguide to thin-film microstrip transition, we are able to achieve an unprecedented 43% instantaneous bandwidth, limited by the receiver's corrugated feedhorn. The measured double-sideband (DSB) receiver noise temperature, uncorrected for optics loss, ranges from 55 K at 275 GHz, 48 K at 345 GHz, to 72 K at 425 GHz. In this frequency range, the mixer has a DSB conversion loss of 2.3 1 dB. The intrinsic mixer noise is found to vary between 17–19 K, of which 9 K is attributed to shot noise associated with leakage current below the gap. To improve reliability, the IF circuit and bias injection are entirely planar by design. The instrument was successfully installed at the Caltech Submillimeter Observatory (CSO), Mauna Kea, HI, in October 2006

    'It's a film' : medium specificity as textual gesture in Red road and The unloved

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    British cinema has long been intertwined with television. The buzzwords of the transition to digital media, 'convergence' and 'multi-platform delivery', have particular histories in the British context which can be grasped only through an understanding of the cultural, historical and institutional peculiarities of the British film and television industries. Central to this understanding must be two comparisons: first, the relative stability of television in the duopoly period (at its core, the licence-funded BBC) in contrast to the repeated boom and bust of the many different financial/industrial combinations which have comprised the film industry; and second, the cultural and historical connotations of 'film' and 'television'. All readers of this journal will be familiar – possibly over-familiar – with the notion that 'British cinema is alive and well and living on television'. At the end of the first decade of the twenty-first century, when 'the end of medium specificity' is much trumpeted, it might be useful to return to the historical imbrication of British film and television, to explore both the possibility that medium specificity may be more nationally specific than much contemporary theorisation suggests, and to consider some of the relationships between film and television manifest at a textual level in two recent films, Red Road (2006) and The Unloved (2009)

    International Aviation Law Anarchy: Zicherman v. Korean Air Lines Dismantles the Warsaw System

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