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Events for March 05, 2012
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Faster and Better: Signal Processing Approaches to High Dimensional MR Neuroimaging
Mon, Mar 05, 2012 @ 10:30 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Research Assistant Professor Justin Haldar, University of Southern California
Talk Title: Faster and Better: Signal Processing Approaches to High Dimensional MR Neuroimaging
Abstract: Magnetic resonance (MR) imaging technologies have enabled new opportunities to reveal the mysteries of the central nervous system -- its function and organization, and what goes wrong when it is injured or diseased. MR experiments are quite flexible, and the MR signal can be manipulated to noninvasively probe anatomy, physiology, and metabolism. However, while MR imaging is decades old and has already revolutionized medical imaging, current methods are still far from utilizing the full potential of the MR signal. In particular, traditional MR methods are based on the Fourier transform, and suffer from fundamental trade-offs between signal-to-noise ratio, spatial resolution, and data acquisition speed. These issues are exacerbated in high-dimensional applications, due to the curse of dimensionality.
Classical approaches to addressing these trade-offs have relied on improved imaging hardware and more efficient pulse sequences. In contrast, our work addresses the limitations of MR using relatively less-explored signal processing approaches, which have recently become practical because of increasing computational capabilities. This talk will illustrate some of our new approaches in the context of MR diffusion imaging, a powerful 6 dimensional imaging modality that can be used to characterize the microstructure and connectivity of the brain. To reconstruct three of these dimensions, we leverage an appropriate imaging model to guide the design of both data acquisition and image reconstruction, which can free us from some of the constraints of traditional Fourier imaging. For the remaining three dimensions, we describe new linear transform techniques to extract important diffusion information from reduced data, i.e., data sampled on the surface of a Fourier 2-sphere. The benefits of these approaches are illustrated in the context of microstructural and connectivity assessments of the brain and spinal cord.
Biography: Justin Haldar received the B.S. and M.S. degrees in electrical engineering in 2004 and 2005, respectively, and the Ph.D. in electrical and computer engineering in 2011, all from the University of Illinois at Urbana-Champaign. He is currently a Research Assistant Professor in the Ming Hsieh Department of Electrical Engineering at the University of Southern California, where he is affiliated with the Signal and Image Processing Institute, the Dana & David Dornsife Cognitive Neuroscience Imaging Center, and the Brain and Creativity Institute. His research interests include image reconstruction, signal modeling, parameter estimation, and experiment design for biomedical imaging applications, with a particular focus on magnetic resonance imaging and spectroscopy. His work on constrained imaging has been recognized with a best student paper award at the 2010 IEEE International Symposium on Biomedical Imaging and the first-place award in the student paper competition at the 2010 international conference of the IEEE Engineering in Medicine and Biology Society. Weblink: http://mr.usc.edu/
Host: Professor Shrikanth Narayanan
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mary Francis
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BME 533 (Seminar in Biomedical Engineering)
Mon, Mar 05, 2012 @ 12:30 PM - 01:50 PM
Alfred E. Mann Department of Biomedical Engineering
Conferences, Lectures, & Seminars
Speaker: Natasha Lepore, USC Keck School of Medicine, Dept. of Radiology, BME & Children's Hospital Los Angeles
Talk Title: Methods for group analyses of neonatal brain MRI data
Biography: Natasha Lepore, Ph.D., Assistant Professor of Research in Radiology at USC and Children's Hospital
Los Angeles, with joint appointment in Biomedical Engineering
Computational anatomy, post-processing methods for structural and diffusion brain MR images, group analyses of normal and abnormal brain development and of brain neurological disorders in adults, genetic analyses in twins
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Mischalgrace Diasanta
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Astani CEE Department Seminar
Mon, Mar 05, 2012 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Kristina M. Wagstrom, Postdoctoral Associate, , Department of Civil Engineering, University of Minnesota
Talk Title: Relating Emissions and Particulate Matter Concentrations in the Complex Ambient Atmosphere
Abstract:
In order for policy makers to effectively regulate emissions, there needs to be a strong understanding of the relationships between emissions and resulting air pollutant concentrations even in the complex mixtures that make up many airsheds. In order to more fully relate sources and ambient pollutant concentrations, I have implemented and evaluated an algorithm capable of tracking the contributions of different sources types and locations to particulate matter concentrations in a three-dimensional atmospheric chemical transport model. I will discuss the details of this algorithm and its utilization to study the origins of particulate matter in the Eastern United States. I used three different approaches in order to create a more complete picture of pollutant origins:
1) I quantified the impacts of emissions from large source regions on the particulate matter concentrations in surrounding areas as pollutants are transported out of those areas into surrounding regions.
2) I studied the contributions from transported pollutants on local air quality problems by identifying the distance pollutants are transported before arriving in regions of interest.
3) I estimated the average age of particulate matter in the atmosphere by tracking when pollutants were emitted. Knowing the age of particulate matter gives us insight into the relative importance of many processes in the atmosphere.
This work has increased our understanding of the impacts of emissions and pollutant transport on particulate matter concentrations. Our studies have suggested that a large fraction of the ground level concentrations of primary (directly emitted) particulate matter in urban areas tend to be from local emissions while the concentrations of secondary species (formed in the atmosphere) such as sulfate or secondary organic particulate matter are more likely to result from regional sources. I found that the distance, direction and amount of particulate matter transport occurring from large source regions was highly variable in time and dependant on particulate matter species. The ages found for particulate matter species were highly variable in time, space (both horizontally and vertically) and by species. Primary species were found to have ages on the order of one to two days while secondary species had ages ranging from one to several days. These results provide information about the relative importance of different reactions and pollutant transport processes in the atmosphere which provides insight for future model development and guidance for policymakers.
Location: Kaprielian Hall (KAP) - 209 Conference Room
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Networking Event with Rocco Fabiano
Mon, Mar 05, 2012 @ 06:00 PM - 09:00 PM
Viterbi School of Engineering Student Organizations
Receptions & Special Events
Networking Event focused on Entrepreneurship
Location: Charlotte S. & Davre R. Davidson Continuing Education Conference Center (DCC) - Figueroa Room
Audiences: Members have first priority, but anyone can RSVP
Contact: USC NOBE
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Tau Beta Pi Info Session
Mon, Mar 05, 2012 @ 06:30 PM - 08:00 PM
Viterbi School of Engineering Student Organizations
Student Activity
Come learn about Tau Beta Pi Engineering Honors Society at our info session. This event is by invitation only, and invited students will notified by email.
Location: James H. Zumberge Hall Of Science (ZHS) - 163
Audiences: Invited students
Contact: Tau Beta Pi
