3,649 research outputs found
Robust F0 Estimation based on a Multichannel Periodicity Function for distant-talking speech
No full textThis work addresses the problem of deriving F0 from distant-
talking speech signals acquired by a microphone network.
The method here proposed exploits the redundancy across
the channels by jointly processing the dierent signals. To
this purpose, a multi-microphone periodicity function is de-
rived from the magnitude spectrum of all the channels. This
function allows to estimate F0 reliably, even under rever-
berant conditions, without the need of any post-processing
or smoothing technique. Experiments, conducted on real
data, showed that the proposed frequency-domain algorithm
is more suitable than other time-domain based ones
Multi-microphone Periodicity Function for Robust F0 Estimation in Real Noisy and Reverberant Environments
No full textThis paper outlines a new method to extract F0 from distant talking speech signals acquired by a microphone network, which exploits the redundancy across the signals proceeding from each microphone, by jointly processing the different contributes. To this purpose, a multi-microphone periodicity function is derived from the magnitude spectrum computed on each microphone signal. This function allows to estimate F0 reliably, even under reverberant conditions, without the need of any post-processing or smoothing technique. Experiments, conducted on real lectures, showed that the proposed frequency-domain algorithm is more suitable than other time-domain based ones
An automatic speaker recognition system for intelligence applications
No full textPublication in the conference proceedings of EUSIPCO, Glasgow, Scotland, 200
On the Use of a Weighted Autocorrelation Based Fundamental Frequency Estimation for a Multidimensional Speech Input
No full textThe problem of computing the fundamental frequency F0 in an accurate way is a known and still partially unsolved problem, especially given a noisy speech input. In this work, a distanttalking scenario is addressed, where a distributed microphone network provides multi-channel input sequences to process for speaker modeling purposes. Given this context, one may process in an independent way each channel and then apply a majority vote or other fusion methods. Otherwise, the redundancy across the channels can be exploited jointly by processing the different signals to obtain a more reliable and robust F0 estimation. The paper investigates the use of a multi-channel version of a Weighted Autocorrelation(WAUTOC)-based F0 estimation technique. A postprocessing corrective step is introduced to improve the resulting F0 accuracy. Experiments conducted on a real database show the advantages and the robustness of the proposed method in extracting the fundamental frequency with no regard about the microphone and talker position as well as the head orientatio
Adaptive weighting of microphone arrays for distant-talking F0 and voiced/unvoiced estimation
No full textThis paper introduces a new technique of multi-microphone processing which aims to provide featuresfor the extraction of fundamental frequency and for the classification of voiced/unvoiced segments in distant-talking speech.A multichannel periodicity function (MPF) is derived from an adaptive weighting of normalized and compressed magnitude spectra.This function highlights periodic clues of the given speech signals, even under noisy and reverberant conditions.The resulting MPF features are then exploited for voiced/unvoiced classification based on Hidden Markov Models.Experiments, conducted both on simulated data and on real seminar recordings based on a network of reversed T-shaped arrays,showed the robustness of the proposed technique
A Competitive Immunoassay for the Detection of Esterolytic Activity of Antibodies and Enzymes
No full textScreening the large number of clones produced in a fusion is often the bottleneck in the isolation of catalytic antibodies. The usual approach requires two steps: clones are first selected for their high affinity to the antigen, then the good binders are tested for their catalytic activity. In order to simplify this selection process, a competitive ELISA assay has been developed that allows direct screening of the antibodies on the basis of their catalytic activity. In this assay, the product of the catalyzed reaction binds to an immobilized anti-product antibody in competition with a peroxidase-product conjugate. The screening assay has been developed for the antibody catalyzed hydrolysis of esters of p-aminophenylacetic acid and has been tested on the PLE4-catalyzed hydrolysis of the same substrates.This test allows the detection of product formation at the nanomolar level, while, in a typical assay, the catalytic activity of PLE can be traced down to 200 fmoles of enzyme. In the standard conditions for the screening of hybridomas obtained from a fusion, the competitive ELISA assay allows detection of catalytic species with values of kcat ** 5 x 10-7 mol l-1 s-1 and kcat/kuncat ** 50. While the assay has been designed for the selection of catalytic antibodies, other potential applications of this methodology are in the screening of libraries of engineered and designed enzymes, and, in general, in the quantitative measurement of enzyme activity
Milano consolato nell' elettione a questo arciuescouado, e promotione alla sagra porpora dell' eminentissimo Federico Visconti : colla sua solennissima entrata seguita a' 11. genaro 1682 e fontioni antecedenti /
No full textFrontispiece coat of arms of Milan, engraved by Federico Agnelli.Signatures: pi⁴ A-G⁴ H⁴(-H4).Mode of access: Internet.Binding: limp vellum. Author & title written on spine
Antibody Catalyzed Modification of Aminoacids. Efficient Hydrolysis of Tyrosine Benzoate.
No full textEsterase antibody 522c2, the first example of a catalytic
antibody specifically programmed to control the reactivity of
functional groups on the side chain of tyrosine, accelerates
the hydrolysis of benzoate esters of L-tyrosine and tyrosinecontaining
dipeptides by a factor of 104 and is moderately
active against other benzoate esters
»It contained harbours that pleased me like sonnets«. Kleine Poetik der diegetischen Karte
No full textIn this article, Federico Italiano explores the relationship between literature and cartography. Beginning with Stevenson’s Treasure Island, the author frames the topic through a general theoretical lens on the spatial dimension of literary texts. He then focuses on a specific phenomenon of literary "carticity"—the diegetic presence of the map, that is, the map as an integral element of the narrative structure. Among others, Italiano examines the works of Houellebecq and Cormac McCarthy
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