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Events for April 04, 2008
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Going Beyond Diffusion Tensor Imaging: Local Reconstruction and Tractography in High Angular..
Fri, Apr 04, 2008 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Maxime Descoteaux, Ph.D. NMR Lab Neurospin / CEA Saclay
FRANCE Abstract:
At the current resolution of diffusion-weighted (DW) magnetic resonance imaging (MRI), research groups agree that there are between one third to two thirds of imaging voxels in the human brain white matter that contain multiple fiber bundles crossing. This presentation tackles the important problem of recovering crossing fiber bundles from high angular resolution diffusion imaging (HARDI) data. The main goal is to overcome the limitations of diffusion tensor imaging (DTI). It is well-known that imaging voxels where there are multiple fiber crossings are locations where DTI is limited and inadequate. In this presentation, a simple, fast and robust Q-ball imaging (QBI) reconstruction is presented using spherical harmonics. QBI is a recent HARDI technique that reconstructs the orientation distribution function (ODF) of the average diffusion of the water molecules in the underlying fiber population. It is able to describe multiple fiber populations crossing. From this diffusion ODF, we describe how we can reconstruct the fiber ODF in order to perform accurate tractography. We develop a new spherical deconvolution sharpening method that transforms the diffusion ODF into a fiber ODF. Finally, we develop a new deterministic tractography algorithm and a new probabilistic tractography algorithm exploiting the full multi-directional information of the fiber ODF. We show local reconstructions and tracking results on complex fiber regions with known fiber crossings from simulated HARDI data, from a biological phantom and from multiple human brain datasets. Most current DTI based methods neglect these complex fibers, which might lead to wrong interpretations of the brain anatomy and functioning.Host: Professor Richard LeahyLocation: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Talyia Veal
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EE Students Practical Guide Seminar Series - Picking a Research Topic
Fri, Apr 04, 2008 @ 11:30 AM - 01:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Seminar Leaders: Profs. Konstantinos Psounis and Alan WillnerWebsite: http://ee.usc.edu/news/practical-guide/* Pizza will be provided by the EE Department.*Abstract: Selecting a research topic is important. It sets the course for the next three-four years of a student's life. What is more, it will define the area of a PhD's job search, and it my very well define the area of interest of a researcher in the industry or academia for years to come. The right research topic can set you on a successful path, and choosing wisely can be a combination of insight and luck. Alternatively, choosing the wrong research topic can cause major problems for any graduate student. Following some introductory remarks regarding right ways and wrong ways to approach this critical problem, this will be an informal conversational meeting with Dr. Psounis and Dr. Lidar, where students will be free to ask any questions about how to choose a good research topic.Biographical SketchesProf. Konstantinos Psounis is an assistant professor of Electrical Engineering and Computer Science at the University of Southern California. He received his first degree from the department of Electrical and Computer Engineering of National Technical University of Athens, Greece, in June 1997, the M.S. degree in Electrical Engineering from Stanford University, California, in January 1999, and the Ph.D. degree in Electrical Engineering from Stanford University in December 2002. Konstantinos models and analyzes the performance of a variety of networks, including the Internet, mobile ad hoc networks, delay and disruptive tolerant networks, sensor networks, mesh networks, peer to peer networks and the web. He also designs methods and algorithms to solve problems related to such systems. He is the author of more than 40 research papers on these topics. Konstantinos has received faculty awards from NSF and the Zumberge foundation, has been a Stanford graduate fellow throughout his graduate studies, and has received the best-student National Technical University of Athens award for graduating first in his class.
Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
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Codes and Capacity for Bidirectional Communication on Lines, Stars, and Rings
Fri, Apr 04, 2008 @ 01:00 PM - 02:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Dr. Gerhard Kramer, Member of Technical Staff, Communications and Statistical Sciences Dept., Bell Labs, Alcatel-LucentABSTRACT: This talk describes codes and capacity bounds for two-way communication in three classes of networks that are elements of larger networks. We begin by considering bidirectional line networks with both edge and node capacity constraints, as well as multiple multi-cast traffic sessions. For wired line networks, we construct an explicit binary network code that achieves capacity. The converse theorem requires using our progressive d-separating edge set (PdE) bound, which is a fundamental generalization of a standard cut bound. Second, we extend the results to line networks with broadcasting nodes by studying a two-way relay channel with three nodes: two sources and a relay. We develop several coded modulation techniques that achieve all rate points inside the capacity region. Third, we extend coding for the three-node topology to many nodes and develop a separation-based coding method that achieves good rates. We show that this approach achieves capacity if the broadcast channels are physically degraded and the multi-access channels exhibit uniform-phase fading. Finally, we outline extensions of the ideas to star and ring networks.BIO: Gerhard Kramer received the B.Sc. and M.Sc. degrees in electrical engineering from the University of Manitoba in Canada and the Dr. sc. techn. (Doktor der Technischen Wissenschaften) degree from the Swiss Federal Institute of Technology (ETH) in Zurich, Switzerland. From July 1998 to March 2000, he was with Endora Tech AG, Basel, Switzerland, as a communications engineering consultant. Since May 2000 he has been with Bell Laboratories, Murray Hill, NJ, USA. His research has been focused on information theory, communications theory, iterative decoding, and source coding.Dr. Kramer is currently serving as an Associate Editor for Shannon Theory for the IEEE Transactions on Information Theory. He served as Guest Editor-in-Chief for an IEEE Transactions on Information Theory Special Issue on Relaying and Cooperation in Communication Networks in 2006-2007, and as Publications Editor for the same Transactions during 2004-2005. He is serving as Co-Chair of the Technical Program Committee for the 2008 IEEE International Symposium on Information Theory. Dr. Kramer is a co-recipient of the IEEE Communications Society 2005 Stephen O. Rice Prize paper award, a Bell Labs President's Gold Award in 2003, and a recipient of an ETH Medal in 1998.HOST: Dr. Alan Willner, willner@usc.edu
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Interm-scale Testing for Process Understanding, Model Validation & Up-scaling of Flow &Trans
Fri, Apr 04, 2008 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Tissa Illangasekare, PE, DEE, DWREAMAX Distinguished Chair of Environmental Sciences and Engineering
And Professor of Civil Engineering
Director, Center for Experimental Study of Subsurface Environmental Processes (CESEP)
Colorado School of Mines, Golden, Colorado, USAABSTRACTGeologic heterogeneity plays a significant role in water flow and complex behavior of chemicals and waste products in the subsurface. A complete knowledge of the governing processes and how they are affected by the heterogeneity are difficult to obtain at field sites due to cost constraints and limitations of currently available technologies and methods for subsurface characterization. Characterization data limitations and lack of access and control at field sites make it difficult to validate theories and prediction models simulating complex flow and transport processes. Intermediate-scale, physical models provide cost effective alternatives that allows for the generation of accurate and high-resolution data at a range of observational scales, under controlled conditions in synthetically created aquifers that are highly instrumented for automated data acquisition. Examples involving numerical and conceptual model validation, soft and hard data assimilation in model calibration, evaluation of remediation technologies, up-scaling from laboratory to field systems and development of new sensor technologies for subsurface monitoring will be presented.Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
