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Experiments on Hiwire database using Denoising and Adaptation with an hybrid HMM-ANN Model
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Parallel implementation of Artificial Neural Network training for speech recognition
Full text linkIn this paper we describe the implementation of a complete ANN training procedure using the block
mode back-propagation learning algorithm for sequential patterns – such as the observation feature vectors
of a speech recognition system – exploiting the high performance SIMD architecture of GPU using
CUDA and its C-like language interface. We also compare the speed-up obtained implementing the training
procedure only taking advantage of the multi-thread capabilities of multi-core processors. In our
implementation we take into account all the peculiar aspects of training large scale sequential patterns,
in particular, the re-segmentation of the training sentences, the block size for the feed-forward and for
the back-propagation steps, and the transfer of huge amount of data from host memory to the GPU card.
Our approach has been tested by training acoustic models for large vocabulary speech recognition
tasks, showing a six times reduction of the time required to train real-world large size networks with
respect to an already optimized implementation using the Intel MKL libraries.
Thanks to these optimizations and to the support of the GPU, the training time for language having a
huge set of training sentences (about one million for Italian) can be reduced from approximately a month
to 5 days
Multi source neural networks based on fixed and multiple resolution analysis for speech recognition
No full textThis paper reports the results obtained by an Automatic Speech Recognition system when MFCCs, J-RASTA Perceptual Linear Prediction Coefficients (J-Rasta PLP) and energies from a Multi Resolution Analysis (MRA) tree of filters are used as input features to a hybrid system consisting of a Neural Network (NN) which provides observation probabilities for a network of Hidden Markov Models (HMM). Furthermore, the paper compares the performance of the system when various combinations of these features are used showing a WER reduction of 20% w.r.t. the use of J-Rasta PLP coefficients, when J-Rasta PLP coefficients are combined with the energies computed at the output of the leaves of an MRA filter tree. Such a combination is practically feasible thanks to the use of a NN architecture designed to integrate multiple features, exploiting the NN capability of mixing several input parameters without any assumption about their stochastical independence. Recognition is performed on a very large test set including many speakers uttering proper names from different locations of the Italian public telephone network
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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