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Events for May 19, 2009
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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
