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Events for January 24, 2012
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Parametric Speech Production Representations for Formant Tracking and Joint Source-filter Modeling
Tue, Jan 24, 2012 @ 02:15 PM - 03:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Daryush Mehta, Harvard University & Medical School, Massachusetts General Hospital
Talk Title: Parametric Speech Production Representations for Formant Tracking and Joint Source-filter Modeling
Abstract: We continue to see an urgent need for robust representations of the acoustic speech waveform, especially in speakers with speech and voice impairments. First, I will discuss our approach to the problem of formant and antiformant tracking, in which extended Kalman algorithms take advantage of a linearized mapping from formant frequencies and bandwidths to cepstral coefficients in an autoregressive moving average model. Second, we will explore joint source-filter models for representing sustained vowel phonation that exhibits nonstationary or asymmetric vocal fold vibration. These algorithms hold potential clinical significance for better understanding acoustic-physiological relationships observable with current imaging systems.
Biography: Daryush Mehta is a Research Associate in Electrical Engineering in the School of Engineering and Applied Sciences at Harvard University, an Assistant Biomedical Engineer at the Center for Laryngeal Surgery and Voice Rehabilitation at the Massachusetts General Hospital, and an Instructor in Surgery at Harvard Medical School. Daryush received his PhD in Speech and Hearing Bioscience and Technology from HarvardâMIT (2010), Master's degree in Electrical Engineering and Computer Science from MIT (2006), and Bachelor's degree in Electrical Engineering from University of Florida (2003). http://people.seas.harvard.edu/~dmehta/
Host: Prof. Shri Narayanan & Dr. Michael Proctor
Location: Ronald Tutor Hall of Engineering (RTH) - 320
Audiences: Everyone Is Invited
Contact: Mary Francis
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor. -
Low-Complexity Equalization for Multi-scale Multi-lag OFDM Channels
Tue, Jan 24, 2012 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Zijian Tang, Research Scientist of TNO the Hague, the Netherlands
Talk Title: Low-Complexity Equalization for Multi-scale Multi-lag OFDM Channels
Abstract: We consider an orthogonal frequency-division multiplexing (OFDM) transmission scheme over wideband underwater acoustic channels, where the propagation paths can experience distinct Doppler effects (manifested in signal scales) and time of arrivals (manifested in delays). We capture such an effect in this paper with a multi-scale multi-lag (MSML) model, and show that the resulting frequency-domain MSML-OFDM channel is subject to inter-carrier interference (ICI), whose amount differs per subcarrier. The corresponding channel matrix can still be approximated as highly sparse, but lacks a specific structure that can optimally be exploited by those low-complexity equalizers proposed for narrowband channels. In this paper, we propose to use the conjugate gradient (CG) algorithm to equalize the channel iteratively. The suitability of the preconditioning technique, that often accompanies the CG to accelerate the convergence, is discussed for the MSML-OFDM channel. We show that in order for the preconditioner to function properly, optimal resampling is indispensable.
Biography: Zijian Tang received the MSc in electrical engineering and the PhD degree from the Delft University of Technology (TU Delft) in 2003 and 2007, respectively. After working with Mathworks for one year, he joined the Sonar Group at Netherlands Organisation for Applied Scientific Research (TNO) in 2008 as a research scientist, where the research area covers underwater acoustic communications, anti-submarine warfare, marine mammal detection etc. Since 2010, he has also been holding a (part-time) research fellow position at the Network & Circuits Group of TU Delft. Zijian Tang is the recipient of the best student paper award (honourable mention) at ICASSP 2007, and was nominated to the Simon Stevin Gezel prize in 2008.
Host: Prof. Urbashi Mitra, ubli@usc.edu, x04667
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
This event is open to all eligible individuals. USC Viterbi operates all of its activities consistent with the University's Notice of Non-Discrimination. Eligibility is not determined based on race, sex, ethnicity, sexual orientation, or any other prohibited factor.
