4,806 research outputs found

    A survey of exemplar-based texture synthesis

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    Exemplar-based texture synthesis is the process of generating, from an input sample, new texture images of arbitrary size and which are perceptually equivalent to the sample. The two main approaches are statistics-based methods and patch re-arrangement methods. In the first class, a texture is characterized by a statistical signature; then, a random sampling conditioned to this signature produces genuinely different texture images. The second class boils down to a clever "copy-paste" procedure, which stitches together large regions of the sample. Hybrid methods try to combine ideas from both approaches to avoid their hurdles. The recent approaches using convolutional neural networks fit to this classification, some being statistical and others performing patch re-arrangement in the feature space. They produce impressive synthesis on various kinds of textures. Nevertheless, we found that most real textures are organized at multiple scales, with global structures revealed at coarse scales and highly varying details at finer ones. Thus, when confronted with large natural images of textures the results of state-of-the-art methods degrade rapidly, and the problem of modeling them remains wide open.Comment: v2: Added comments and typos fixes. New section added to describe FRAME. New method presented: CNNMR

    Classification of bijections between 321- and 132-avoiding permutations

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    It is well-known, and was first established by Knuth in 1969, that the number of 321-avoiding permutations is equal to that of 132-avoiding permutations. In the literature one can find many subsequent bijective proofs of this fact. It turns out that some of the published bijections can easily be obtained from others. In this paper we describe all bijections we were able to find in the literature and show how they are related to each other via ``trivial'' bijections. We classify the bijections according to statistics preserved (from a fixed, but large, set of statistics), obtaining substantial extensions of known results. Thus, we give a comprehensive survey and a systematic analysis of these bijections. We also give a recursive description of the algorithmic bijection given by Richards in 1988 (combined with a bijection by Knuth from 1969). This bijection is equivalent to the celebrated bijection of Simion and Schmidt (1985), as well as to the bijection given by Krattenthaler in 2001, and it respects 11 statistics--the largest number of statistics any of the bijections respects

    PPM-Decay: A computational model of auditory prediction with memory decay

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    Statistical learning and probabilistic prediction are fundamental processes in auditory cognition. A prominent computational model of these processes is Prediction by Partial Matching (PPM), a variable-order Markov model that learns by internalizing n-grams from training sequences. However, PPM has limitations as a cognitive model: in particular, it has a perfect memory that weights all historic observations equally, which is inconsistent with memory capacity constraints and recency effects observed in human cognition. We address these limitations with PPM-Decay, a new variant of PPM that introduces a customizable memory decay kernel. In three studies—one with artificially generated sequences, one with chord sequences from Western music, and one with new behavioral data from an auditory pattern detection experiment—we show how this decay kernel improves the model’s predictive performance for sequences whose underlying statistics change over time, and enables the model to capture effects of memory constraints on auditory pattern detection. The resulting model is available in our new open-source R package, ppm (https://github.com/pmcharrison/ppm)

    An Experimental Study Utilizing the Treanor Method with the Left – Over Child

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    It was the purpose of the study (1) to compare the ability in expressive language of a group of Fifth, Sixth and Seventh grade Students before introducing the Treanor Method and after their working with it for a nine week period, and (2) to measure reading vocabulary in an effort to determine the amount of gain, if any, through the use of this method. The main question the study attempted to answer was: Will there be a change in creative writing ability after an intensive training program using the Treanor techniques with a group of children with language difficulties

    Perspectives on Gerhard: Selected Proceedings of the 2nd and 3rd International Roberto Gerhard Conferences

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    Perspectives on Gerhard expands several papers given at the 2nd and 3rd International Roberto Gerhard Conferences in 2012 and 2013. The book focuses on two aspects of Gerhard. Firstly, the pre-1939 period in which he was a student of Schoenberg and then, on returning to Catalonia, began to establish a reputation as a composer. Secondly, and more generally on the composer's stylistic and aesthetic evolution. This latter focus includes both Gerhard's approach to serialism both harmonically and melodically as well as the pivotal role the USA was to play in his later life. The book concludes with two personal reminiscences given at the conferences by Ferran Gerhard and Mariona Agustí Badia

    A Diachronic Analysis of the Translation of English Sound Symbolism in Italian Comics

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    Phonosymbolic elements such as ideophones and interjections test the translator’s ability in various ways. These forms would, in theory, require a complete change of form and substance of the source text but this has not always been possible because of graphical, cultural and linguistic reasons, and this led, in certain cases, to a foreignized target-text environment. Recent research has started to consider the relationship between verbal and visual modes as beneficial and not just as a mere constraint for the translator. This research aims to align itself with this approach in order to analyze how verbal and visual modes in Disney comic books have come together to welcome sound symbolic forms and how translators have dealt with them in Italian Disney comics, in particular. In order to clarify the behavior, function, translation and use of expressive sound symbolic devices in Italian Disney comics, this article will offer a diachronic analysis of these strategies as found in a diachronic bidirectional corpus compiled through extensive archival research
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