18,471 research outputs found

    Locally Convex Words and Permutations

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    We introduce some new classes of words and permutations characterized by the second difference condition π(i−1)+π(i+1)−2π(i)≀k\pi(i-1) + \pi(i+1) - 2\pi(i) \leq k, which we call the kk-convexity condition. We demonstrate that for any sized alphabet and convexity parameter kk, we may find a generating function which counts kk-convex words of length nn. We also determine a formula for the number of 0-convex words on any fixed-size alphabet for sufficiently large nn by exhibiting a connection to integer partitions. For permutations, we give an explicit solution in the case k=0k = 0 and show that the number of 1-convex and 2-convex permutations of length nn are Θ(C1n)\Theta(C_1^n) and Θ(C2n)\Theta(C_2^n), respectively, and use the transfer matrix method to give tight bounds on the constants C1C_1 and C2C_2. We also providing generating functions similar to the the continued fraction generating functions studied by Odlyzko and Wilf in the "coins in a fountain" problem.Comment: 20 pages, 4 figure

    Ornament and craft:Digital design and the profession

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    The separation of ornament from Modern architecture declared famously in Adolf Loos’ essay “Ornament and Crime” placed space as the primary concern of architecture, with evidence of craftsmanship and symbolism removed from the canonical and conventional public buildings of the past century. Yet, Harvard Graduate School of Design’s historian Professor Antoine Picon notes the widespread return of ornamental expression in architecture today is “inseparable from the massive diffusion of the computer” and furthered by a “weakening in the tectonic approach and the increased importance attached to surface.” In Cellular Tessellation (CT)—a project developed for Vivid Sydney 2014, an 18-day festival of light, music and ideas – this contemporary problem of the separation of surface from structure was addressed as a core area of interest, as were ornament and the expressive potential of architecture through digitally enabled craftsmanship

    The First World War between Memory and History: A Conference Retrospective

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    Long after the guns of the First World War went silent on 11 November 1918, the war continues to spark debate. The many points of contention were on full display at the “From Memory to History” conference, hosted by Western University in London, Ontario, over three days in November 2011. Scholars and enthusiasts from around the world gathered to share, debate, and ultimately demonstrate that the war’s many legacies are still open to interpretation, even as the centenary of the war’s outbreak approaches. Perhaps the most crucial lesson learned is that both memory and history are malleable concepts, prone to revision, and there are numerous narratives in many disciplines that remain untold, even with an event as well-documented as the First World War

    Introduction: histories of asylums, insanity and psychiatry in Scotland

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    This paper introduces a special issue on ‘Histories of madness, asylums and psychiatry in Scotland’, situating the papers that follow in an outline historiography of work in this field. Using Allan Beveridge’s claims in 1993 about the relative lack of research on the history of psychiatry in Scotland, the paper reviews a range of contributions that have emerged since then, loosely distinguishing between ‘overviews’ – work addressing longer-term trends and broader periods and systems – and inquiries that get in deep with particular ‘individuals and institutions’. There remains much still to do, but the present special issue signals what is currently being achieved, not least by a new generation of scholars in and on Scotland

    The Impact of Olfactory Cues on Attention: The Case of Stroop Interference

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    This study explores the relationship between odor imagery, color associations, and visual attention through a Stroop-task based on common odor-color associations. This Stroop-task was designed using three fruits with odor-color associations: lime with green, strawberry with red, and lemon with yellow. Each possible word-color combination was lexically presented in the experimental trials. Three experiments were conducted that used the Stroop-task with different odors present. They suggest that odor imagery can affect visual attention, the inhibition of odor-color associations, and that odor imagery appears to be facilitated in the presence of a related odor

    Evaluation of an Algorithm for the Automatic Detection of Salient Frequencies in Individual tracks of Multi-track Musical Recording

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    This paper evaluates the performance of a salient frequency detection algorithm. The algorithm calculates each FFT bin maximum as the maximum value of that bin across an audio region and identifies the FFT bin maximum peaks with the highest five deemed to be the most salient frequencies. To determine the algorithm’s efficacy test subjects were asked to identify the salient frequencies in eighteen audio tracks. These results were compared against the algorithm’s results. The algorithm was successful with electric guitars but struggled with other instruments and in detecting secondary salient frequencies. In a second experiment subjects equalised the same audio tracks using the detected peaks as fixed centre frequencies. Subjects were more satisfied than expected when using these frequencie

    The Impact f Olfactory Cues on Attention: The Case of Reverse Stroop Interference

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    Ham and Koch (2019) found that an odorant could influence interference on a modified Stroop task. This study was conducted to examine the impact of olfactory cues on reverse Stroop interference. Across three experiments, participants completed a modified reverseStroop task in which they identified a word (strawberry, lime, lemon) in different color fonts (red, green, yellow). Although the words were fruit names instead of color names, each word had some degree of association with a particular color (e.g., lime and green). In Experiment 1, congruent and incongruent trials were presented without an odorant. No differences were found between congruent and incongruent trials (t(28) = .63, p \u3e .05; d = .12). Experiment 2 consisted of the same task; however, an orange odorant was added to the room. RTs were faster for congruent trials than incongruent trials (t(17) = 4.15, p \u3c .001; d = .98). Lavender odorant was used in Experiment 3 to test whether the RT differences in Experiment 2 were influenced by the presence of a related odorant or any odorant. No differences were found between conditions (t(27) = 1.89, p \u3e .05; d = .36). The results indicate that a task-related odorant can impact word identification in a modified Stroop task

    Trans-Relativistic Supernovae, Circumstellar Gamma-Ray Bursts, and Supernova 1998bw

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    Supernova (SN) 1998bw and gamma-ray burst (GRB) 980425 offer the first direct evidence that supernovae are the progenitors of some GRBs. However, this burst was unusually dim, smooth and soft compared to other bursts with known afterglows. Whether it should be considered a prototype for cosmological GRBs depends largely on whether the supernova explosion and burst were asymmetrical or can be modeled as spherical. We address this question by treating the acceleration of the supernova shock in the outermost layers of the stellar envelope, the transition to relativistic flow, and the subsequent expansion (and further acceleration) of the ejecta into the surrounding medium. We find that GRB 980425 could plausibly have been produced by a collision between the relativistic ejecta from SN 1998bw and the star's pre-supernova wind; the model requires no significant asymmetry. This event therefore belongs to a dim subclass of GRBs and is not a prototype for jet-like cosmological GRBs.Comment: 5 pages, 2 figures, to appear in Gamma 2001, eds. S. Ritz, N. Gehrels, and C. Shrade

    Forecasted 21 cm constraints on compensated isocurvature perturbations

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    A "compensated" isocurvature perturbation consists of an overdensity (or underdensity) in the cold dark matter which is completely cancelled out by a corresponding underdensity (or overdensity) in the baryons. Such a configuration may be generated by a curvaton model of inflation if the cold dark matter is created before curvaton decay and the baryon number is created by the curvaton decay (or vice-versa). Compensated isocurvature perturbations, at the level producible by the curvaton model, have no observable effect on cosmic microwave background anisotropies or on galaxy surveys. They can be detected through their effect on the distribution of neutral hydrogen between redshifts 30 to 300 using 21 cm absorption observations. However, to obtain a good signal to noise ratio, very large observing arrays are needed. We estimate that a fast Fourier transform telescope would need a total collecting area of about 20 square kilometers to detect a curvaton generated compensated isocurvature perturbation at more than 5 sigma significance.Comment: 7 pages, v2: minor typos corrected, reflects PRD accepted versio

    An investigation into the efficacy of methods commonly employed by mix engineers to reduce frequency masking in the mixing of multitrack musical recordings

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    Studio engineers use a variety of techniques to reduce frequency masking between instruments when mixing multi-track musical recordings. This study evaluates the efficacy of three techniques, namely mirrored equalization, frequency spectrum sharing and stereo panning, against their variations to confirm the veracity of accepted practice. Mirrored equalisation involves boosting one instrument and cutting the other at the same frequency. Frequency spectrum sharing involves low pass filtering one instrument and high pass filtering the other. Panning involves placing two competing instruments at different pan positions. Test subjects used eight tools comprising a single unlabeled slider to reduce frequency masking in several two instrument scenarios. Satisfaction values were recorded. Results indicate subjects preferred using tools that panned both audio tracks
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