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Events for March 11, 2010
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Photonics Seminar: Resonant single sideband modulators
Thu, Mar 11, 2010 @ 01:00 PM - 02:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Dr. Andrey Matsko, OEwaves Inc.Abstract: Optical modulators up-convert RF signals to the optical domain and are key components in all microwave photonics applications. Modulators that have a very large bandwidth are naturally desired in wideband applications. This is generally obtained at the expense of lower power efficiency. Unlike standard wideband lithium niobate and electro-absorption varieties, modulators in narrowband microwave photonics feature extremely high efficiency. The high efficiency is obtained with resonance coupling to RF electrodes and/or the use of optical resonance devices. This approach leads to filtering, in addition to light modulation, which is desirable in virtually all narrowband applications. Here we present a new class of modulators with the unique feature of providing a narrow modulation bandwidth over a very wide RF frequency range. This feature opens up new and compelling applications such as widely tunable microwave photonic receivers as well as tunable opto-electronic oscillators.Bio: Dr. Andrey Matsko is an internationally recognized expert in theory of whispering gallery mode micro-resonators as well as quantum and nonlinear optics. He has over 100 journal publications in the fields and holds 12 US patents. He is a Principal Engineer at OEwaves Inc., where he is involved in studies of properties and applications of whispering gallery modes in dielectric optical resonators. Previously, being employed as a principal member of technical staff at Jet Propulsion Laboratory (JPL), he has initiated, participated, and led theoretical investigations of RF photonic receivers, miniature electro-optical modulators, opto-electronic oscillators, and tunable narrowband filters. He has studied and developed theoretical models based on which novel types of whispering gallery mode resonators with novel functionalities have been produced. He has investigated and developed models for noise and stability parameters of novel oscillators based on linear and nonlinear properties of whispering gallery mode resonators. He received 2005 JPL's Lew Allen Award for Excellence ("For seminal and unique theoretical contributions in quantum optics, in particular, the nonlinear interactions of optical crystalline whispering gallery mode resonators, leading to the establishment of this new area of research at JPL") and a NASA Space Act Award in recognition of contributions to the National Space Program and to the mission of the Jet Propulsion Laboratory.
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Jing Ma
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Long-Term Context Modeling for Acoustic- Linguistic Emotion Recognition
Thu, Mar 11, 2010 @ 02:00 PM - 03:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Abstract:
The automatic estimation of human affect from the speech signal is an important step towards making virtual agents more natural and human-like. Thus, we present a novel technique for incremental recognition of the
user's emotional state as it is applied in a Sensitive Artificial Listener (SAL) system, designed for socially competent human-machine communication. Our method is capable of using acoustic, linguistic, as well as long-range contextual information in order to continuously predict the current quadrant in a two-dimensional emotional space spanned by the dimensions valence and activation. The main system components are a hierarchical Dynamic Bayesian Network for detecting linguistic keyword features and Long Short-Term Memory recurrent neural networks which model phoneme context and emotional history to predict the affective state of the user. We evaluate various keyword spotting model architectures for linguistic feature generation as well as different strategies for extracting relevant acoustic features from the speech signal. Conducting experiments on the SAL corpus of non-prototypical real-life emotional speech, we obtain a quadrant prediction accuracy that is comparable to the average inter-labeler consistency.
Bio:
Martin Wöllmer works as a researcher funded by the European Community's Seventh Framework Programme project SEMAINE at the Technische Universität München (TUM). He obtained his bachelor degree and his
diploma in Electrical Engineering and Information Technology from TUM for his works in the field of multimodal data fusion and robust automatic speech recognition, respectively. His current research and teaching activity includes the subject areas of pattern recognition and speech processing. Thereby his focus lies on robust keyword detection in emotionally colored and noisy speech, emotion recognition, and speech feature enhancement. Publications of his in various journals, books, and conference proceedings cover novel and robust modeling architectures for speech and emotion recognition such as Switching Linear Dynamic Models, Long Short-Term Memory recurrent neural nets, or Graphical Models.Location: Ronald Tutor Hall of Engineering (RTH) - 320
Audiences: Everyone Is Invited
Contact: Mary Francis
