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Conferences, Lectures, & Seminars
Events for May
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Evaluation of Human Brain MRI Registration Algorithms
Fri, May 01, 2009 @ 02:30 PM - 03:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Arno Klein,
Assistant Professor of Clinical Neurobiology,
Columbia UniversityAbstract: All fields of neuroscience that employ brain imaging need to communicate their results with reference to anatomical regions. Inparticular, comparative morphometry and group analysis of functionaland physiological data require coregistration of brains to establishcorrespondences across brain structures. It is well established thatlinear registration of one brain to another is inadequate for aligning brain structures,so numerous algorithms have emerged to nonlinearly register brains to one another. This study is the largest evaluation of nonlinear deformation algorithms applied to brain image registration ever conducted. Fourteen algorithms from laboratories around the world are evaluated using 8 different error measures. Morethan 45,000 registrations between 80 manually labeled brains were performed by algorithms including: AIR, ANIMAL, ART, Diffeomorphic Demons, FNIRT, IRTK, JRD-fluid, ROMEO, SICLE, SyN, and four different SPM5 algorithms ("SPM2-type" and regular Normalization, Unified Segmentation, and the DARTEL Toolbox). All of these registrations were preceded by linear registration between the same image pairs using FLIRT. One of the most significant findings of this study is that the relative performances of the registration methods under comparison appear to be little affected by the choice of subject population, labeling protocol, and type of overlap measure. This is important because it suggests that the findings are generalizable to new subject populations that are labeled or evaluated using different labeling protocols. Furthermore, we ranked the 14 methods according to three completely independent analyses (permutation tests, one-way ANOVA tests, and indifference-zone ranking) and derived three almost identical top rankings of the methods. ART, SyN, IRTK, and SPM's DARTEL Toolbox gave the best results according to overlap and distance measures, with ART and SyN delivering the most consistently high accuracy across subjects and label sets. Updates will be published on the http://www.mindboggle.info/papers/ website.Hosted by Professor Richard Leahy
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Talyia Veal
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An Open Platform for Robotics Research
Mon, May 04, 2009
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Time: 3 PM - 3:50 PMLocation: SSL 150Title: An Open Platform for Robotics Research
Speakers: Steve Cousins and Brian Gerkey
Host: Maja J MataricAbstract:
Personal Robotics research and development are accelerating. A growing community of Open Source developers is creating a platform called ROS that anyone can build on to make the breakthroughs that will lead to new applications. Willow Garage is building a personal robot platform, PR2, which has two arms, a mobile base, and a rich sensor suite. This talk will review the current status of ROS and PR2, and discuss opportunities to join the ROS Open Source community.Speaker Bios:
Steve Cousins is the President and CEO of Willow Garage. Before Willow, Steve was a senior manager at IBM's Almaden Research Center. He has been on the senior staff of the Palo Alto Research Center (PARC), and a researcher at Interval Research Corporation. Steve holds a PhD in CS from Stanford University, and Bachelor's and Master's degrees from Washington University.
Brian Gerkey is the Director of Open Source Development at Willow Garage. Before Willow, Brian was a computer scientist in the SRI Artificial Intelligence Center, and a postdoctoral scholar in the Stanford Artificial Intelligence Lab. Brian holds PhD and MS degrees in computer science from USC, and a BSE degree in computer engineering from Tulane University.
Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Front Desk
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Software Safety - May4-7, 2009
Mon, May 04, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
SFT 09-2
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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Seminar: Robust Heterogeneous Systems in Emerging Technologies: A TFT-CMOS 3D System for Testable/Re
Wed, May 06, 2009 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Jing Li
PhD Candidate, Purdue UniversityAbstract:
Moore's law has provided a metronome for semiconductor technology over the past four decades. However, when CMOS feature size and interconnect dimensions approach the fundamental limit, aggressive scaling no longer plays an exclusive role in improving performance. An emphasis on emerging technologies and computational paradigms has been placed. To meet the fast growing demand for system functionality, heterogeneous system that utilizes and optimizes the best of different technologies is becoming one of the most promising solutions for future complex system design. In heterogeneous system, Si CMOS will continue to play a major role for high performance computation while the other technologies can add special functions that are either difficult, expensive, or even not achievable with standard silicon CMOS. However, designing such ultra-complex systems with various technologies also poses a set of new challenges (in terms of design, test, fabrication and integration). Those challenges will ultimately lead to a paradigm shift from traditional system design (assembling separate functional blocks) to a completely new paradigm (designing them in a holistic way). In the new paradigm, device engineering and system design should not be considered separately. On the contrary, an optimal system design should consider the strong interaction between technology/device and circuit/system. To demonstrate the feasibility of the proposed system design concept, in this talk, I will focus on one interesting technology - flexible electronics (Thin Film Transistors). This technology has been widely used in LCD applications due to its low cost and manufacturability on flexible substrates (polymer, flexible glass, etc.). However, further application of TFT is limited by its performance, reliability, and inherent material induced process variations (i.e., grain boundary). To cope with these challenges, both modeling and design techniques have been developed. In particular, I will discuss device optimization, statistical simulation methodology for estimation of process variations, followed by an efficient circuit-level variability compensation technique. Optimized LTPS TFTs with higher current drivability and less variability would make them as an effective add-on (as auxiliary functions) to Si CMOS, opening up a plethora of new and interesting applications. At architecture level, I will focus on one such application â€" low-cost and robust Si-TFT heterogeneous system design with on-line/off-line built-in-test circuits, implemented in LTPS-TFTs, to test the underlying silicon CMOS die. Such a system significantly reduces the test cost and improves the controllability and observability of the underlying Si CMOS die for ensuring highly reliable and testable operations. Bio:
Jing (Vicky) Li is a PH.D. candidate from the Electrical and Computer Engineering department at Purdue University, West Lafayette, IN. She received the B.S. degree from Electrical Engineering at Shanghai Jiao Tong University, Shanghai, China, in 2004. In 2008 summer, she worked as a research intern at IBM Semiconductor Research and Development Center (SRDC), Fishkill, NY. She has received the IBM PH.D. fellowship award in 2008, the Dean's and Semester Honors for outstanding scholastics performance (Graduate School Fellowship) from Purdue University in 2007, the Meissner Fellowship from Purdue University in 2004 and Geare scholarship from Purdue and Shanghai Jiao Tong University in her undergraduate senior year (2003). She was also the recipient of the 2005~2006 Magoon's award for excellence in teaching from Purdue University. Her primary research focus encompasses the development of innovative techniques for green heterogeneous systems using emerging technologies (flexible electronics, spintronics, etc.) integrated with Si CMOS. This research has a strong emphasis on interdisciplinary field between device physics, material science and VLSI circuit/system design, bridging the technical gap between fundamental devices physics and high-level system design/optimization.Location: Hughes Aircraft Electrical Engineering Center (EEB) - -248
Audiences: Everyone Is Invited
Contact: Estela Lopez
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Fundamentals of Geotechnical & Geoenvironmental Data Management
Wed, May 06, 2009 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Peaker: Salvatore Caronna, B.S., M.S., P.E.; President and Founder of gINT Software, Santa Rosa, CAAbstract:The primary purpose of data collection, querying, and analysis is to enable the engineer to make sound decisions. All too often data management is an ad-hoc process with little or no coordination between parties generating and consuming the data. Further, data tend to be compartmentalized with manual or quasi-automated methods of sharing the information. Inappropriate tools are often used to manage and manipulate the information, resulting in flawed design and implementation.
This presentation discusses the ramifications of flawed design and illustrates appropriate methods in dealing with project data.Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Image Reconstruction and Aberration Sensing by Phase Retrieval
Wed, May 06, 2009 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
James R. Fienup, Ph.D.,
Robert E. Hopkins Professor of Optics,
Professor of Electrical and Computer Engineering
University of RochesterAbstract: Phase retrieval has been under development for image reconstruction and wavefront sensing. Application areas include astronomy, space-object imaging with both active-coherent and passive-incoherent illumination, wave-front and telescope-misalignment sensing (e.g. Hubble and James Webb space telescopes), and 3-D coherent imaging. This talk will review some of the highlights of phase retrieval development and some recent advances in phase retrieval approaches and algorithms that have occurred in the last few years.Biography: James R. Fienup received an A.B. in physics and mathematics from Holy Cross College (Worcester, MA), and M.S. and Ph.D. (1975) degrees in Applied Physics from Stanford University, where he was a National Science Foundation Graduate Fellow. He performed research for 27 years at the Environmental Research Institute of Michigan and Veridian Systems, where he was a Senior Scientist. He joined the faculty at the University of Rochester in 2002 as the Robert E. Hopkins Professor of Optics. He also holds positions as Professor, Center for Visual Science, Professor of Electrical and Computer Engineering, and Senior Scientist, Laboratory for Laser Energetics. Professor Fienup is a Fellow of the Optical Society of America (OSA) and of the International Society for Optical Engineering (SPIE), and is a Senior Member of IEEE. He was awarded the Rudolf Kingslake Medal and Prize for 1979 by the SPIE and the International Prize in Optics for 1983 by the International Commission for Optics. He was Editor-in-Chief of the Journal of the Optical Society of America A, 1997-2003. He previously served as Division Editor of Applied Optics - Information Processing, Associate Editor of Optics Letters, and Chair of the OSA Publications Council of the OSA.Professor Fienup's research interests center around imaging science. His work includes unconventional imaging, phase retrieval, wavefront sensing, and image reconstruction and restoration. These techniques are applied to passive and active optical imaging systems, synthetic-aperture radar, and biomedical imaging modalities. His past work has also included diffractive optics and image quality assessment. He has over 180 publications and 4 patents.Host: B. Keith Jenkins, jenkins@sipi.usc.eduLocation: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Talyia Veal
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The role of thermal undulations in adhesion of a biological membrane
Wed, May 06, 2009 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
L. B. FreundDivisions of Engineering, Brown University,Providence, RI 02912Fibroblasts and other tissue secreting cells have the ability to adhere to extracellular matrix and to migrate in the course of tissue generation. Adhesion occurs through specific bonding of integrins, large transmembrane protein molecules in the cell wall, to ligands in the surrounding tissue. Integrins are mobile in the cell wall and diffuse randomly in a normal thermal environment. The mean density of integrins in the cell wall is normally too low for adhesion to occur casually upon contact. Instead, adhesions form gradually as a few integrins become immobilized in a small region. Such focal adhesion regions usually grow to about a micron or two in diameter.
Such adhesion patches have been studied at a coarse scale by means of a number of experimental approaches. In a departure from this trend, Arnold et al. [ChemPhysChem 5 (2004) 383] carried out experiments in which they were able to study the process of cell adhesion at the scale of individual binding sites. Among their observations was the discovery that there appeared to be an upper bound on spacing of integrin bond sites for tight adhesions to form. Furthermore, the critical value of this density was found to be essentially uniform among the four cell types examined. This raises the tantalizing question as to whether or not this remarkable finding can be understood in terms of a fundamental physical phenomenon across the cell types. In this presentation, the question will be examined from the point of view of classical statistical mechanics with bonding being represented by a well in the potential energy landscape of the system. It will be shown that thermal fluctuations arising from immersion of the membrane in a heat bath can account for the appearance of a critical bond site spacing.
Location: Seaver Science Library (SSL) - Rm 150
Audiences: Everyone Is Invited
Contact: April Mundy
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Advanced System Safety Analysis - May 11-15, 2009
Mon, May 11, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
ADVSS 09-2
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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Human Factors In Aviation Safety - May11-15, 2009
Mon, May 11, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
HFH 09-5
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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Gas Turbine Engine Accident Investigation - May18-22, 2009
Mon, May 18, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
GTAI 09-2
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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Incident Investigation/Analysis - May18-21, 2009
Mon, May 18, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
IIA 09-2
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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On Optimal Fix-free Codes
Tue, May 19, 2009 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Serap Savari,
Texas A&M UniversityAbstract: Fix-free codes are variable length codes in which no codeword is the prefix or suffix of another codeword. They have been investigated for joint source-channel coding and have been applied within the video standards H.263+ and MPEG-4 because their property of efficient decoding in both the forward and backward directions assists with error resilience. They are also interesting for problems in information retrieval such as searching for patterns directly in compressed text. We provide a low-complexity heuristic to produce fix-free codes. The design of optimal or minimum-redundancy fix-free codes has been a longstanding open problem. We offer the first solution both to this problem and to a variation in which all codewords are also required to be palindromes.Biography: Serap Savari is an Associate Professor in the Department of Electrical and Computer Engineering at Texas A&M University. She received four degrees from MIT. Professor Savari was a Member of Technical Staff in the Computing Sciences Research Center at Bell Labs from 1996-2003 and was an Associate Professor at the University of Michigan from 2004-2007. Her research interests include information theory and data compression. She was an Associate Editor for Source Coding for the IEEE Transactions on Information Theory from 2002-2005. She was the Bell Labs representative to the DIMACS council from 2001-2003 and has been a member of the program committees for many conferences and workshops.Host: Gerhard Kramer, gkramer@usc.edu, EEB 536, x07229Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
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CS Colloq: Nirupama Bulusu
Tue, May 19, 2009 @ 11:00 AM - 12:30 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Time: 11 AM - 12:30 PMLocation: SAL 222Talk title: Resource-efficient Audiovisual Sensing
Speaker: Prof. Nirupama Bulusu(Portland State University)
Host: Prof. Ramesh GovindanAbstract:
Animal calls, street signs, car honks, etc. The physical world is permeated with sounds and images that can be captured and analyzed using audiovisual sensor networks. Both sensing modalities feature high sampling rates or large sample sizes making them challenging to implement on embedded platforms with sharply limited energy, bandwidth and processing resources.In this talk, I will first show how we have built resource-efficient audiovisual sensing applications on embedded platforms. Application-specific system architectures and compressive sensing algorithms reduce the amount of data sampled and transmitted at each sensor. I will present three real world case studies: cane-toad monitoring; PetrolWatch, a fuel price collection
application; and noise pollution monitoring.Second, many image sensing applications require accurate camera position and orientation in 3D space. Currently, the most accurate camera localization method requires the resource-intensive task of detecting and matching several feature points visible in frames taken from each camera, which is unreasonable for resource constrained sensors. I will describe the
design and evaluation of a highly accurate, robust, efficient, distributed 3D localization system suitable for embedded image sensors that significantly reduces the costs of the point correspondence problem, by using a special 3D target.This talk describes joint work with colleagues at Portland State University, and the University of New South Wales.Bio:
Nirupama Bulusu received the B.Tech degree from Indian Institute of Technology (IIT), Madras, India in 1997, the M.S degree from the University of Southern California in 2000 and the Ph.D degree from the University of California Los Angeles (UCLA) in 2002, all in computer science. Since 2004, she has been an Assistant Professor of Computer Science at Portland State
University. Her research interests lie in sensor networks, with an emphasis on environmental and urban sensing applications. She is a recipient of the NSF CAREER award.
Location: Henry Salvatori Computer Science Center (SAL) - 222
Audiences: Everyone Is Invited
Contact: CS Front Desk
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Atmospheric processes alter the physico-chemical properties of ...
Tue, May 19, 2009 @ 02:00 PM - 05:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
primary ultrafine particles and
their impact on public exposureOral Defense by: Zhi Ning, Ph.D. Candidate,
Sonny Astani Department of Civil and Environmental EngineeringAbstract:Primary sources, especially vehicle emissions, are the dominant contributors of ambient particulate matter (PM) in urban environments. Upon their emissions from primary sources, ambient PM undergoes various atmospheric processes which may alter their physic-chemical and toxicological properties before the exposure to the public. This thesis first investigates the physic-chemical properties of ambient ultrafine aerosols characterized as from primary source in the immediate vicinity of a major freeway in Los Angeles. Then the thesis examines the atmospheric processes (dilution and photochemical oxidation) that dominate the dynamics of primary aerosols following their emission. Atmospheric dilution affects the dynamic behavior of aerosols by affecting the ambient concentration levels of non-labile PM species and also shifting the gas-particle partitioning of the semi-volatile PM component. This study discusses the roles of dilution in changing the physico-chemical properties of the ambient aerosols by comparing the normalized fuel-based emission factors of various PM species. This information is complemented with an investigation of secondary aerosol formation from atmospheric photochemical reactions that alters the PM volatility, solubility and chemical properties. Based on the experimental investigation, the thesis reviews the recent findings that link PM semi-volatile components and their redox activity, and also discusses the influence and importance of PM volatility on particle toxicity. Lastly, this thesis discusses possible metrics to regulate PM emissions and establish ambient air quality standards that are pertinent to public health, and suggests future investigations aimed to improve our current understanding of the adverse health effects of public exposure to ambient aerosols.Location: Kaprielian Hall (KAP) - 460
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Variable-to-Fixed Channel Coding Against Infrastructure Link Failures
Wed, May 20, 2009 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Osvaldo Simeone,
New Jersey Institute of TechnologyAbstract: Two models are discussed that illustrate the advantages of variable-to-fixed channel coding (i.e., the broadcast coding approach) for scenarios in which wireless communications is aided by an unreliable wired infrastructure. In the first scenario, a single macrocell, serving a number of outdoor users, is overlaid with a femtocell, which includes several home users. The femtocell is served by a home base station, which is connected to the macrocell base station via an unreliable connection (e.g., DSL). In the second scenario, a source communicates with a remote destination via a number of distributed relays. Communication from source to relays takes place over a (discrete or Gaussian) broadcast channel, while the relays are connected to the receiver via orthogonal and unreliable finite-capacity links.In both scenarios, link failures are assumed to be non-ergodic and unpredictable, and robust communications strategies are designed that deliver a variable information rate depending on the current (unknown) link conditions. Upper and lower bounds are derived on the achievable rates of interest, and some optimality conditions are obtained.Biography: Osvaldo Simeone received the M.Sc. degree (with honors) and the Ph.D. degree in Information Engineering from Politecnico di Milano, Milan, Italy, in 2001 and 2005 respectively. He is currently with the Center for Wireless Communications and Signal Processing Research (CWCSPR), at the New Jersey Institute of Technology (NJIT), Newark, New Jersey, where he is an Assistant Professor. His current research interests concern the cross-layer analysis and design of wireless networks with emphasis on information-theoretic, signal processing and queuing aspects. Specific topics of interest are: cognitive radio, cooperative communications, ad hoc, sensor, mesh and hybrid networks, distributed estimation and synchronization. Dr. Simeone currently serves as an Editor for IEEE Trans. Wireless Commun.Host: Urbashi Mitra, ubli@usc.edu, EEB 540, x04667Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Gerrielyn Ramos
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Aviation Security Program Management - May26-29, 2009
Tue, May 26, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
AVSEC 09-2
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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Empirical Game-Theoretic Analysis for Practical Strategic Reasoning
Tue, May 26, 2009 @ 10:30 AM - 12:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Speaker: Michael Wellman (University of Michigan)Host: Prof.Milind TambeAbstract:
The games agents play--in markets, conflicts, or most other contexts--often defy strict game-theoretic analysis. Games may be unmanageably large (combinatorial or infinite state or action spaces), and present severely imperfect information, which could be further complicated by partial dynamic revelation. Moreover, the game may be specified procedurally, for instance by a simulator, rather than in an explicit game form.With colleagues and students over the past few years, I have been developing a body of techniques for strategic analysis, adopting the game-theoretic framework but employing it in domains where direct "model-and-solve" cannot apply. This empirical game-theoretic methodology embraces simulation, approximation, statistics and learning, and search. Applications to canonical market games, for example, yields improved bidding strategies for simultaneous ascending auctions and continuous double auctions. Simulation-based studies of rich trading scenarios further demonstrate the value of empirical methods for extending the scope of game-theoretic analysis.Brief bio:
Michael Wellman received a PhD from the Massachusetts Institute of Technology in 1988 for his work in qualitative probabilistic reasoning and decision-theoretic planning. From 1988 to 1992, Wellman conducted research in these areas at the USAF's Wright Laboratory. For the past 15+ years, his research has focused on computational market mechanisms for distributed decision making and electronic commerce. As Chief Market Technologist for TradingDynamics, Inc. (now part of Ariba), he designed configurable auction technology for dynamic business-to-business commerce. Wellman previously served as Chair of the ACM Special Interest Group on Electronic Commerce (SIGecom), and as Executive Editor of the Journal of Artificial Intelligence Research. He is a Fellow of theAssociation for the Advancement of Artificial Intelligence and the Association for Computing Machinery.
Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Front Desk
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Threat And Error Management Development - May27-29, 2009
Wed, May 27, 2009
Aviation Safety and Security Program
Conferences, Lectures, & Seminars
TEM 09-3
For more information and to register for Aviation Safety and Security Program courses, please visit http://viterbi.usc.edu/aviation.Audiences: Registered Audiences Only
Contact: Viterbi Professional Programs
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Throughput Performance in Cognitive Radio Networks
Thu, May 28, 2009 @ 11:30 AM - 12:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Abstract:
Cognitive radio is a promising technology to mitigate spectrum shortage in wireless communications. It enables secondary users (SUs) to opportunistically access low-occupancy primary spectral bands as long as the primary user (PU) access is protected. PU protection is vital to the success of cognitive radio system because no PU would be inclined to accommodate secondary cognitive networks without such assurance. Such a protection requirement is particularly challenging for multiple SUs over a potentially wide geographical area. In this talk, I will present our results on the fundamental limit on the throughput performance of cognitive networks under the PU packet collision probability constraint. We consider two cases. In the case of perfect sensing, we develop an optimum spectrum access strategy under generic PU traffic. Moreover, we develop and evaluate a distributed access scheme that enables multiple SUs to collectively protect the PU while adapting to changes in the PU activity pattern.
In the case of imperfect sensing, we develop an optimal threshold-based sensing-transmission structure that goes beyond the widely studied periodic structure. Our results provide useful insight on the trade-off between the protection of the primary user and the throughput performance of the secondary users. Last, if time permits, I will briefly discuss our current progress on feedback-based access and power control for distributed multiuser cognitive networks.Bio:
Xin Liu is an associate professor in the Computer Science Department at the University of California, Davis. Before joining UC Davis, she was a postdoctoral research associate in the Coordinated Science Laboratory at UIUC. She received her Ph.D. degree in electrical engineering from Purdue University in 2002. Her research is on wireless communication networks, with a focus on resource allocation and cognitive radio networks. She received the Best Paper of Year Award of the Computer Networks Journal in 2003 for her work on opportunistic scheduling. She received NSF CAREER award in 2005 for her research on "Smart-Radio-Technology-Enabled Opportunistic Spectrum Utilization." She received the Outstanding Engineering Junior Faculty Award from the College of Engineering, University of California, Davis, in 2005.
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Bhaskar Krishnamachari
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Alfred E. Mann Innovation in Engineering Seminars 2009
Fri, May 29, 2009 @ 01:30 PM - 03:00 PM
Alfred E Mann Institute
Conferences, Lectures, & Seminars
Speaker: Hsiusheng Hsu, Mann Fellow - Materials Science "Microlaser Biosensor"
Location: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Susan Cooper
