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Events for February 08, 2007
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The Theory behind IDEAL: Cramer-Rao Bounds for Chemical Species Separation in Magnetic Resonance Im
Thu, Feb 08, 2007 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
The Theory behind IDEAL: Cramer-Rao Bounds for Chemical Species Separation in Magnetic Resonance ImagingAngel R. Pineda, PhD
Department of Mathematics
CSU-FullertonAbstract:The separation of water and fat in MRI through the acquisition of images at multiple echo times provides a robust method for fat suppression in areas where the field is inhomogeneous and fat saturation pulses fail. By accurately estimating the fat component, we are also able to explore diagnostic information that may exist in the fat image. In this talk, we will show how to propagate the imperfections of the magnetic field into our estimate of water and fat and use this understanding to optimize the imaging parameters. Introducing the imperfections in the magnetic field in the estimation of the water and fat makes the estimation nonlinear. The optimization of data acquisition based on the Cramer-Rao bound for this nonlinear problem leads to a new optimal solution. Our acquisition and reconstruction is part of the IDEAL method for chemical species separation.Bio:Dr. Pineda received his BS from Lafayette College in 1995, his PhD in Mathematics from the University of Arizona in 2002, and completed a postdoctoral fellowship in Radiology at Stanford University in 2006. He is the author of 15 refereed journal articles, and has made numerous contributions to CT and MRI reconstruction, including optimization of the IDEAL fat-water separation technique which is emerging as a gold-standard for MRI-based fat-water imaging. He recently joined the faculty in the Department of Mathematics at CSU-Fullerton.Host: Krishna S. Nayak, 0-3494, knayak@usc.edu http://ee.usc.edu/Location: Room: EEB 248
Audiences: Everyone Is Invited
Contact: Talyia Veal
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Modeling and Optimization of Data Gathering Protocols in Wireless Sensor Networks
Thu, Feb 08, 2007 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
CSI INTERNAL SEMINARSPEAKER: Professor Bhaskar Krishnamachari, CENGABSTRACT: The most dominant approach to the development of querying and data-gathering protocols in wireless sensor networks can be characterized as "design by intuition, validate by simulation". Given the severe resource constraints in these systems, it is essential to complement this perspective with mathematical modeling and optimization. Such modeling has both descriptive and prescriptive uses, which we illustrate through a couple of case studies. In the first study, we derive scaling laws for query-based sensor networks, identifying the application conditions under which it is possible to deploy arbitrarily large sensor networks when the resources per node are kept bounded. In the second, we use an optimization framework to design a fair and efficient rate-control scheme for data gathering.
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
