1,651 research outputs found
A Comparison of Front-Ends for Bitstream-Based ASR over IP
Automatic speech recognition (ASR) is called to play a relevant role in the provision of spoken interfaces for IP-based applications. However, as a consequence of the transit of the speech signal over these particular networks, ASR systems need to face two new challenges: the impoverishment of the speech quality due to the compression needed to fit the channel capacity and the inevitable occurrence of packet losses.
In this framework, bitstream-based approaches that obtain the ASR feature vectors directly from the coded bitstream, avoiding the speech decoding process, have been proposed ([S.H. Choi, H.K. Kim, H.S. Lee, Speech recognition using quantized LSP parameters and their transformations in digital communications, Speech Commun. 30 (4) (2000) 223–233. A. Gallardo-Antolín, C. Pelàez-Moreno, F. Díaz-de-María, Recognizing GSM digital speech, IEEE Trans. Speech Audio Process., to appear. H.K. Kim, R.V. Cox, R.C. Rose, Performance improvement of a bitstream-based front-end for wireless speech recognition in adverse environments, IEEE Trans. Speech Audio Process. 10 (8) (2002) 591–604. C. Peláez-Moreno, A. Gallardo-Antolín, F. Díaz-de-María, Recognizing voice over IP networks: a robust front-end for speech recognition on the WWW, IEEE Trans. Multimedia 3(2) (2001) 209–218], among others) to improve the robustness of ASR systems. LSP (Line Spectral Pairs) are the preferred set of parameters for the description of the speech spectral envelope in most of the modern speech coders. Nevertheless, LSP have proved to be unsuitable for ASR, and they must be transformed into cepstrum-type parameters. In this paper we comparatively evaluate the robustness of the most significant LSP to cepstrum transformations in a simulated VoIP (voice over IP) environment which includes two of the most popular codecs used in that network (G.723.1 and G.729) and several network conditions. In particular, we compare ‘pseudocepstrum’ [H.K. Kim, S.H. Choi, H.S. Lee, On approximating Line Spectral Frequencies to LPC cepstral coefficients, IEEE Trans. Speech Audio Process. 8 (2) (2000) 195–199], an approximated but straightforward transformation of LSP into LP cepstral coefficients, with a more computationally demanding but exact one. Our results show that pseudocepstrum is preferable when network conditions are good or computational resources low, while the exact procedure is recommended when network conditions become more adverse.Publicad
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Distance constraints on activation of TRPV4 channels by AKAP150-bound PKCα in arterial myocytes.
TRPV4 (transient receptor potential vanilloid 4) channels are Ca2+-permeable channels that play a key role in regulating vascular tone. In arterial myocytes, opening of TRPV4 channels creates local increases in Ca2+ influx, detectable optically as "TRPV4 sparklets." TRPV4 sparklet activity can be enhanced by the action of the vasoconstrictor angiotensin II (AngII). This modulation depends on the activation of subcellular signaling domains that comprise protein kinase C α (PKCα) bound to the anchoring protein AKAP150. Here, we used super-resolution nanoscopy, patch-clamp electrophysiology, Ca2+ imaging, and mathematical modeling approaches to test the hypothesis that AKAP150-dependent modulation of TRPV4 channels is critically dependent on the distance between these two proteins in the sarcolemma of arterial myocytes. Our data show that the distance between AKAP150 and TRPV4 channel clusters varies with sex and arterial bed. Consistent with our hypothesis, we further find that basal and AngII-induced TRPV4 channel activity decays exponentially as the distance between TRPV4 and AKAP150 increases. Our data suggest a maximum radius of action of ∼200 nm for local modulation of TRPV4 channels by AKAP150-associated PKCα
El tabernáculo de Guillermo de Orta para la capilla del Sagrario de la catedral de Córdoba
El trabajo se centra en el análisis del tabernáculo del Sagrario de la catedral de Córdoba como imagen del Santo Sepulcro de Jerusalén, en el contexto de la capilla del Sagrario que se concibe como Casa de la Sabiduría y del conjunto catedralicio que se presenta como la Nueva Jerusalén de Córdoba en el siglo XVI, centuria en la que se convierte en uno de los puntos neurálgicos del ceremonial litúrgico celebrado en el espacio sacralizado de la antigua aljama de Córdoba, identificándose la ciudad celeste con la ciudad real.This work focuses on the tabernacle in the Sanctuary of Cordoba Cathedral as an image of the Holy Sepulchre of Jerusalem, in the context of the Sanctuary Chapel. This was designed as a House of Wisdom inside the Cathedral, which in the sixteenth century was thought of as the ‘New Jerusalem of Cordoba’. In this century, it became one of the key venues for the liturgical ceremonies held in the sanctified area of the old Mosque of Cordoba, and this celestial city was identified closely with the real city
Banks’ Net Interest Margin in the 2000s: A Macro-Accounting International Perspective
This paper re-examines the determinants of Net Interest Margin (NIM) in the banking industries
of 15 developed and emerging economies. It presents three main contributions
with respect to previous studies: first, we analyze the determinants of NIM in the years
leading to the 2008 financial crisis; second, we account for the role of different accounting
standards across countries; third, we use multi-way cluster estimation methodologies
which control for cross-sectional and time-series dependence in macroeconomic and
banking variables. We find that the introduction of International Financial Reporting
Standards (IFRSs) contributed to lower NIM variations unexplained by standard accounting
variables. Interest rate volatility is found to be positively and strongly related to
NIM dynamics, whereas inflation risk is often found to be a relevant driver of NIM crosscountry
differences
A Comparison of the Ovulation Method With the CUE Ovulation Predictor in Determining the Fertile Period
The purpose of this study was to compare the CUE Ovulation Predictor with the ovulation method in determining the fertile period. Eleven regularly ovulating women measured their salivary and vaginal electrical resistance (ER) with the CUE, observed their cervical-vaginal mucus, and measured their urine for a luteinizing hormone (LH) surge on a daily basis. Data from 21 menstrual cycles showed no statistical difference (T= 0.33, p= 0.63) between the CUE fertile period, which ranged from 5 to 10 days (mean = 6.7 days, SD = 1.6), and the fertile period of the ovulation method, which ranged from 4 to 9 days (mean = 6.5 days, SD = 2.0). The CUE has potential as an adjunctive device in the learning and use of natural family planning methods
Time Series
This paper first shows that survey-based expectations (SBE) outperform standard time
series models in U.S. quarterly inflation out-of-sample prediction and that the term structure
of survey-based inflation forecasts has predictive power over the path of future inflation
changes. It then proposes some empirical explanations for the forecasting success
of survey-based inflation expectations. We show that SBE pool a large amount of heterogeneous
information on inflation expectations and react more flexibly and accurately
to macro conditions both contemporaneously and dynamically. We illustrate the flexibility
of SBE forecasts in the context of the recent financial crisis
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