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Conferences, Lectures, & Seminars
Events for January
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Subjective Quality of Mobile Video Streaming
Tue, Jan 15, 2008 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Michal RiesInstitute of Communications and Radio-Frequency Engineering, Vienna University of Technology
Vienna, AustriaABSTRACT:
Provisioning of mobile video streaming is hitting toward to limitations in channel quality and capacity as well as in terminal processing power. These known limitations, network settings, and video content influence the end-user quality. To select optimal video streaming settings, it is important to consider corresponding quality requirements based on human perception. The intention of this talk is to explain recent trends in video quality estimation for mobile video services.Biography:
Michal Ries is currently a research assistant and working towards his Ph.D. degree at Vienna University of Technology, Institute of Communications and Radio-Frequency Engineering. He received his B.S. and M.S. degrees in 2002 and 2004 at the Slovak University of Technology, Faculty of Electrical Engineering and Information Technology in Bratislava. Before he joined TU Vienna he was working for Siemens PSE as system engineer. His research interests include perceptual video and audiovisual quality evaluation, video and audiovisual metric design, monitoring of QoS in wireless networks, video streaming in wireless network optimization.Host: Professor Sanjit Mitra
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Talyia Veal
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Representation of Signal Sets for the Analysis of Pathogen Variability
Wed, Jan 16, 2008 @ 10:00 AM - 11:00 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Professor Paul Dan Cristea
Biomedical Engineering Center,
University "Politehnica" of BucharestAbstract: It is often desirable to analyze sets of related signals in a way that separates the joint variation of the set, from the individual features of each component signal. The specific case that prompted our research is the genomic signal analysis of taxon variability, but the problem is general and the methods presented in the paper can be used to improve the description of many other types of signal sets. To better express variations of related signals in a given set , where the individual signals are , with xi – the sampling points and yi – the corresponding signal values, it is advantageous to describe the signal set by using two types of components:
(1) a reference sequence that gives the central tendency of the set, i.e., the common variation
of the signals;
(2) the individual offsets of the signals with respect to the chosen reference:
.
The central tendency that is used as reference must extract optimally the common variation of the signals in the considered set, so that the individual offset of each signal expresses only the features specific to that signal, with minimum crosstalk. Various estimates of the central trend have been used as reference: average sequence of the signals (or other linear combination of the signals), median sequence , mode step sequence , and maximum flat sequence .The method has been used to analyze pathogen variability resulting in treatment resistance. Mutations occurring at specific sites along a segment comprising codons 509-595 of the rpoB gene of Mycobacterium tuberculosis (MT), which encodes thesub-unit of RNA polymerase, can be put in direct correspondence to Rifampin (RMP) resistance. Similarly, the variability of polymerase and reverse transcriptase genes of HIV-1, Clade F, has also been monitored this way to detect resistance to the antiretroviral treatment of AIDS.Biography: Professor Paul Cristea graduated from the Faculty of Electronics and Telecommunications (UPB - University "Politehnica" of Bucharest, Romania, 1962), the Faculty of Physics (University of Bucharest, 1969), and has a Ph.D. in Technical Physics (UPB, 1970). Since then his research and teaching activities covered an large area of Electrical Engineering and related domains including topics like Digital Signal and Image Processing, Genomic Signals, Neural and Evolutionary Systems, Computerized Medical Equipment, Evolutionary Intelligent Agents, Intelligent e-Learning Environments. He is the author or co-author of more then 130 published papers, 11 patents and contributed to more then 20 books in these fields. He is currently affiliated with UPB, the Biomedical Engineering Center (general director) and the Vrije Universiteit Brussel, Belgium, the ETRO Department. He is a corresponding member of the Romanian Academy and director of the Romanian Bioinformatics Society.Host: Prof. Sanjit MitraLocation: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Talyia Veal
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One Dimensional Nanostructures and their Applications - Dr. M. Meyyappan
Wed, Jan 16, 2008 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Nanotechnology SeminarOne Dimensional Nanostructures and their ApplicationsDr. M. MeyyappanNASA Ames Research CenterHost: Professor Chongwu Zhou, Electrical EngineeringAbstract: The ability to grow a variety of semiconductor, oxide and other inorganic
materials in the form of nanowires with controlled properties and vertical orientation
provides a competitive avenue for applications in logic, memory, data storage, sensors
and others. Growth of these nanowires using a vapor-liquid-solid approach, material
characterization and application development will be discussed in detail. In addition, an
overview of carbon nanotube based chemical and biosensors will be presented covering
CNT preparation, sensor fabrication and sensor performance. The author acknowledges
contributions from Bin Yu, Jeff Sun, Jing Li, Y. Lu and Jun Li.
Biography: Dr. Meyya Meyyappan is Chief Scientist for Exploration Technology at the
Center for Nanotechnology, NASA Ames Research Center in Moffett Field, CA. Until
June 2006, he served as the Director of the Center for Nanotechnology as well as Senior
Scientist. He holds an Adjunct Professor position at the Arizona State University. He is a
founding member of the Interagency Working Group on Nanotechnology (IWGN)
established by the Office of Science and Technology Policy (OSTP). The IWGN is
responsible for putting together the National Nanotechnology Initiative.
For his contributions and leadership in nanotechnology, he has received numerous awards
including: a Presidential Meritorius Award; NASA's Outstanding Leadership Medal;
Arthur Flemming Award given by the Arthur Flemming Foundation and the George
Washington University; 2008 IEEE Judith Resnick Award; IEEE-USA Harry Diamond
Award. For his educational contributions, he has received: Outstanding Recognition
Award from the NASA Office of Education; the Engineer of the Year Award (2004) by
the San Francisco Section of the American Institute of Aeronautics and
Astronautics(AIAA); IEEE-EDS Education Award. Dr. Meyyappan has authored or coauthored
over 175 articles in peer reviewed publications and made over 200
Invited/Keynote/Plenary Talks in nanotechnology subjects across the world.Location: Frank R. Seaver Science Center (SSC) - 319
Audiences: Everyone Is Invited
Contact: Ericka Lieberknecht
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There and Back Again: Linking Regional and Global Air Quality and Climate
Wed, Jan 16, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Kevin Bowman Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA Recent advances in observational capabilities, global chemistry transport models, and data assimilation techniques have the potential to revolutionize our understanding of global and regional air quality. This progress has been enabled in part by the Tropospheric Emission Spectrometer (TES), a high-resolution Fourier Transform spectrometer aboard the NASA Aura spacecraft that provides the global distribution of vertical ozone and carbon monoxide profiles. These observations can characterize how pollutants such as ozone can be transformed and transported on global scales with important implications for both regional air quality and climate. In particular, I will discuss research in understanding the contribution of surface emissions to tropical tropospheric ozone and the impact of summertime ozone over North America on chemistry climate coupling. In addition, we will explore a new effort to develop "sensor webs" that can combine ground, aircraft, and satellite observations with adjoint modeling techniques to design optimal sampling strategies that maximize the information available in these observations. I will show how sensor webs could be used in intensive air quality campaigns and their potential role for global environmental monitoring.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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CS Colloquia: Bertrand Competition in Networks
Thu, Jan 17, 2008 @ 11:00 AM - 12:30 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Title: Bertrand Competition in NetworksSpeaker: Prof. Shuchi Chawla (Wisconsin)ABSTRACT:
The Internet is a unique modern artifact given its sheer size and the
number of its users. Given its continuing distributed and ad-hoc
evolution, there have been growing concerns about the effectiveness of
its current routing protocols in finding good routes and ensuring
quality of service. Imposing congestion-based and QoS-based prices on
traffic has been suggested as a way of combating the ills of this
distributed growth and selfish use of resources. Unfortunately, the
effectiveness of such approaches relies on the cooperation of the
multiple entities implementing them, namely the ISPs or Internet
service providers. The goals of the ISPs do not necessarily align with
the social objectives of efficiency and quality of service; their
primary objective is to maximize their own profit. It is therefore
imperative to study the following question: given a large
combinatorial market such as the Internet, suppose that the owners of
resources selfishly price their product to maximize their own profit,
and consumers selfishly purchase resources to maximize their own
utility, how does this effect the functioning of the market as a
whole?We study this problem in the context of a simple network pricing game,
and analyze the performance of equilibria arising in this game as a
function of the degree of competition in the game, the network
topology, and the demand structure. Economists have traditionally
studied such questions in single-item markets. It is well known, for
example, that monopolies cause inefficiency in a market by charging
high prices, whereas competition has the effect of driving prices down
and operating efficiently. Our work extends the classical Bertrand
model of competition from economics to the network setting. For
example, we ask: is competition in a network enough to ensure
efficient operation? does performance worsen as the number of
monopolies grows? does the answer depend in an interesting way on the
network topology and/or demand distribution? We provide tight bounds
on the performance (efficiency) of the network.This is joint work with Tim Roughgarden.BIO:
Shuchi Chawla is an assistant professor of Computer Science at
University of Wisconsin - Madison. She received her PhD in 2005 from
Carnegie Mellon University and her Bachelor of Technology degree from
the Indian Institute of Technology, Delhi, India in 2000. Her research
interests lie in theoretical computer science, with emphasis towards
approximation algorithms, combinatorial optimization, and game theory.
Shuchi is the recepient of an NSF CAREER award and an IBM Ph.D.
fellowship.Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: CS Colloquia
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Geological Storage as a Carbon Mitigation Option
Thu, Jan 17, 2008 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Lyman Handy Colloquium SeriesPresentingMichael Celia
Princeton UniversityAbstractThe most promising approach to solve the carbon problem involves widespread implementation of zero-emission power plants. One promising option is to use fossil fuel-based plants with carbon capture and storage (CCS) technology. While a variety of storage options are being studied, geological storage appears to be most viable. Injection of captured CO2 into deep geological formations leads to a fairly complex flow system involving multiple fluid phases, a range of potential geochemical reactions, and mass transfer across phase interfaces.
General models of this system are computationally demanding, with the problem made more difficult by the large range of spatial scales involved, and the importance of local features for both fluid flow and geochemical reactions. An especially important local feature involves leakage pathways, with one example being abandoned wells associated with the century-long legacy of oil and gas exploration and production. Such pathways also have large uncertainties associated with their properties.
Therefore, inclusion of leakage in the storage analysis requires resolution of multiple scales, and incorporation of large uncertainties.
Taken together, these render standard numerical simulators ineffective due to their excessive computational demands. A series of simplifications to the governing equations can reduce computational demands, and ultimately render the system solvable by analytical or semi-analytical methods. These solutions, while restrictive in their assumptions, allow for large-scale analysis of leakage in a probabilistic framework. An example from Alberta, Canada will be used to demonstrate the utility of these solutions.Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce Sapir
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Wireless Ad-Hoc Networks: From Probability to Physics via Information Theory
Thu, Jan 17, 2008 @ 01:30 PM - 02:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Professor Massimo Franceschetti,
University of California, San DiegoABSTRACT: In this interdisciplinary talk we consider the problem of determining the information capacity of a network of wireless transmitters and receivers and try to draw some non-trivial connections between spatial stochastic processes, physics, and information theory.We present the following main result of statistical physics flavor: By distributing uniformly at random an order of n nodes wishing to establish pair-wise independent communications inside a domain of size of the order of n, the per-node information rate must follow an inverse square-root of n law, as n tends to infinity.The above claim originally due --in slightly different form-- to Gupta and Kumar (2000), requires both the construction of a network
operation scheme that achieves the required rate, and an information-theoretic proof of the optimality of such a scheme, at least in the scaling limit sense.We present a scheme due to Franceschetti, Dousse, Tse, and Thiran (2007) which relies on the theory of percolation and achieves the
inverse square-root of n law. Then, departing from the traditional information-theoretic approach of postulating fading channel and path loss models, we apply directly Maxwell's physics of wave propagation in conjunction to Shannon's theory of information, to obtain the "natural" upper bound on the scaling limit of the per-node rate and show that the inverse square-root of n bound is tight. This is a recent result of Franceschetti, Migliore, and Minero (2007).The conclusion is that claims (abundant in the literature) of surpassing the inverse square-root of n law, are artifacts of unrealistic channel modeling assumptions that hide the natural spatial constraints revealed by the Maxwell-Shannon approach.Host: Prof. Urbashi Mitra, ubli@usc.eduLocation: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Uncertainty and Bayesian inference in inverse problems
Thu, Jan 17, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Youssef Marzouk, Massachusetts Institute of Technology"Uncertainty and Bayesian inference in inverse problems"Predictive simulation rests on validated models, which often must be conditioned on indirect observations. In this context, Bayesian statistics provides a foundation for inference from noisy and limited data, a natural mechanism for regularization in the form of prior information, and a quantitative assessment of uncertainty in the objects of inference. Inverse problemsâ€"representing indirect estimation of model parameters, inputs, or structural componentsâ€"can be fruitfully cast in this framework. Complex and computationally intensive forward models arising in physical applications, however, can render a Bayesian approach prohibitive. This difficulty is compounded by high dimensionality, as when the unknown is a spatial field.We present new algorithmic developments for Bayesian inference in this context, showing strong connections with the forward propagation of uncertainty. In particular, we introduce a stochastic spectral formulation that accelerates the Bayesian solution of inverse problems via rapid evaluation of a surrogate posterior. We also pursue dimensionality reduction for the inference of spatiotemporal fields, using truncated Karhunen-Loève representations of Gaussian process priors. These approaches are demonstrated on scalar transport problems arising in contaminant source inversion and in the inference of inhomogeneous transport properties.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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CS Colloquia: Network Resilience to Attack and Disaster
Thu, Jan 17, 2008 @ 03:30 PM - 05:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Title: Network Resilience to Attack and DisasterSpeaker: Prof. Dan Rubenstein (Columbia)ABSTRACT:
Traditional network design can compensate for a small number of node
and link failures, but cannot handle attacks or failures on a massive
scale. These massive-scale phenomena may be due to malicious behavior
in the network, such as a denial of service attack, or due to
disaster, such as an emergency sensor network deployed in a
catastrophic location such as a fire or flood. A primary focus of our
research has been to design or enhance routing protocols so that they
are more resilient to these massive-scale challenges. The talk will
first cover the Secure Overlay Services (SOS) architecture we proposed
that utilizes network overlays to proactively protect targeted
Internet sites from distributed denial of service (DDoS) attacks.
Next, we will explore the problem of maximizing the amount of data
that can be extracted to a base-station from a sensor network whose
nodes are undergoing rapid failures. We develop a novel distributed
network coding technique and demonstrate how, in a massive failure
setting, our coding/routing technique outperforms prior state-of-the-art. I
will finish the talk with a brief run-through of other projects that
our lab has focused on.BIO:
Dan Rubenstein is an Associate Professor of Electrical Engineering and
Computer Science at Columbia University. He received a B.S. degree in
mathematics from M.I.T., an M.A. in math from UCLA, and a PhD in computer
science from University of Massachusetts, Amherst. His research interests are
in network technologies, applications, and performance analysis, with a
substantial emphasis on resilient and secure networking, distributed
communication algorithms, and overlay technologies. He has received an NSF
CAREER Award, an IBM Faculty Award, the Best Student Paper award from the ACM
SIGMETRICS 2000 conference, and a Best Paper award from the IEEE ICNP 2003
Conference.Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Colloquia
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Acoustic Communications, Modem-Based Navigation Aids, and Undersea Networks
Fri, Jan 18, 2008 @ 10:00 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Dale Green, Teledyne BenthosABSTRACT: Over the past two years considerable interest has arisen within the world-wide academic community concerning the development of
concepts for undersea wireless networks. In this talk, I will present the core technologies developed by Teledyne Benthos on underwater acoustic
communications. Our Telesonar modem is the enabling system for the navy's Seaweb program, and it is the foundation of several underwaternavigation aids, environmental sensing systems, passive
sonar systems, and portable tracking ranges for submarines.Our Telesonar acoustic modems have a history dating back over ten years. The original modem was used as the development platform of underseanetworking via the Seaweb program from the Space and Naval
WarfareSystems Command (SPAWAR). Over the years, the capabilities of Telesonar modems have grown from a few tens of bits per second (bps) with marginal reliability to today's wide range of modulation schemes suitable for a wide range of environmental and operational conditions. At the same
time, the size and power consumption of the modem has declined dramatically. In this talk, I will describe some key features of our modems and their potential applications, such as the range rate technique, low-power wake-up, multiple access signaling, networking, and modem based navigation and environmental sensing.BIO: Teledyne Benthos is an industry leader in developing acoustic modems for underwater communication and networking. Dale Green is the
Chief Scientist at Teledyne Benthos with responsibilities for advanced developments in acoustic communications and signal processing. He
specializes in theory, algorithm development, and implementation of digital communications in adverse channels. He currently is the PI formultiple SBIR and BAA programs, and originated the concepts and
methodsused in the PUTS submarine tracking program. He is the principal architect for enhancements to the Teledyne Benthos line of acoustic modems and has for ten years supported SPAWAR in the development of
networked acoustic communications. Mr. Green was the PI for a successful feasibility study and demonstration project for providing the
Swedish Navy with a Fleet-wide acoustic communications system. He has consulted with the Swedish Navy in developing techniques for active
sonar for ASW purposes. Education: M.S., Electrical Engineering, San Diego State University; M.S., Applied Physics, University of California,San Diego; M.S., Ocean Engineering, University of
Hawaii; B.A., Mathematics, University of California, Los Angeles.HOST: Wei Ye, weiye@ISI.EDULocation: Information Science Institute (ISI) - - 11th Floor Conference Room
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Munushian Visiting Seminar - Dr. Herschel Rabitz
Fri, Jan 18, 2008 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Friday, January 18, 2008Dr. Herschel RabitzPrinceton University"Control in the Micro-World:From Quantum Systems to Bio-Systems"Hedco Neuroscience Building (HNB 100)Hosted by Prof. Hossein HashemiAbstract
The study of quantum system dynamics and biosystem dynamics have generally developed as distinct Subjects with their own scientific issues, technical aspects and applications. However, when these subjects are considered in the context of controlling their respective dynamical behavior many common conceptual threads and even algorithms for operation become apparent by their linkage to systems analysis. These common operational features exist despite the fact that quantum systems and biosystems operate on vastly different temporal and spatial scales. In the case of quantum systems, manipulation of their dynamics may be affected by ultrafast shaped laser pulses while in the case of biosystems genetic and molecular engineering as well as applied chemical fluxes can play analogous roles. The presentation will be given in two parts respectively on quantum system and biosystem dynamics, with an attempt at the end to draw attention to their common features.Bio
Herschel A. Rabitz graduated from Harvard University in 1970, with a Ph.D. degree in chemical physics. This was followed by post-doctoral work at the University of Wisconsin. In 1971, Professor Rabitz joined the faculty of the Department of Chemistry
at Princeton University, and from July, 1993 to July, 1996 was Chairman of the Department. He is also an affiliated member of Princeton's Program in Applied and Computational Mathematics. Professor Rabitz's research interests lie at the interface of chemistry, physics, and engineering, with principal areas of focus including molecular dynamics, biophysical chemistry, chemical kinetics, and optical interactions with matter. An overriding theme throughout his research is the emphasis on molecular scale systems analysis. Professor Rabitz has over 700 publications in the general area of chemical physics.Location: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Ericka Lieberknecht
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Unlocking Heavy Oil and Unconventional Resources with Heat
Tue, Jan 22, 2008 @ 12:45 AM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Anthony KovscekStanford
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce Sapir
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Living Conductors: The Nature and Implications of Electrical Transport in Bacterial Nanowires
Tue, Jan 22, 2008 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Graduate SeminarbyProfessor Mohammad El-NaggarUniversity of Southern California
Los Angeles, CAAbstract:Bacterial nanowires are conductive pilus-like appendages produced by bacteria, most notably some 'metal-reducers', in direct response to electron acceptor limitation. These recently discovered supramolecular assemblies represent a new paradigm in extracellular electron transfer, but the mechanism of electron transport remains unclear. This talk will feature quantitative measurements of transport across bacterial nanowires produced by the dissimilatory metal-reducing bacterium (DMRB) Shewanella oneidensis MR-1, whose electron transport system holds practical promise for renewable energy recovery and bioremediation. The Shewanella nanowires display a surprising non-linear electrical transport behavior, where the voltage dependence of the conductance reveals peaks indicating discrete energy levels with higher electronic density of states. These results indicate that the molecular constituents along the Shewanella nanowires possess an intricate electronic structure that plays a role in mediating the overall electron transport. We will highlight the vast implications of signal transduction at the biological-inorganic interface as well as devices that exploit this interface, such as microbial fuel cells. We will also discuss our recent efforts to develop experimental and image analysis tools that target the interactions between the living and non-living worlds at this interface.Tuesday, January 22, 2008
Seminar at 12:45p.m.
OHE 122
The Scientific Community is Cordially Invited.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce Sapir
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CS Colloquia: Social Robots
Tue, Jan 22, 2008 @ 03:30 PM - 05:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Title: Social RobotsSpeaker: Prof. Reid Simmons (CMU)ABSTRACT:
As robots become more ubiquitous in society, they will have to learn to
interact with people in socially acceptable ways. For the past six years,we
have been developing techniques that enable robots to behave according to
social conventions, both conversationally and spatially. The techniquesinvolve
explicit modeling of human behavior and social conventions,probabilistic
reasoning about situations and the intentions of people, and explicit
representation of affect and mutual interaction. We have developed several
robots that embody these ideas, including GRACE, a robot that attended the
National Conference on Artificial Intelligence, the roboceptionist, a joint
project with the School of Drama, and a robot that dances rhythmically with
children. This talk will describe our efforts in this area, focusing on the
techniques that we have developed and highlighting the gap that still remains
between the behavior of our robotsand true social interaction.BIO:
Reid Simmons is a Research Professor in the School of Computer Science at
Carnegie Mellon University. He earned his B.A. degree in 1979 in
ComputerScience from SUNY at Buffalo, and his M.S. and Ph.D. degrees from MIT
in 1983 and 1988, respectively, in the field of Artificial Intelligence. Since
coming to Carnegie Mellon in 1988, Dr. Simmons' research has focusedon
developing self-reliant robots that can autonomously operate over extended
periods of time in unknown, unstructured environments. This work involves
issues of robot control architectures, probabilistic planning and reasoning,
monitoring and fault detection, and robust indoor and outdoornavigation. More
recently, Dr. Simmons has focused on the areas of human-robot social
interaction, coordination of multiple heterogeneous robots, and formal
verification of autonomous systems. Over the years, he has been involved in the
development of over a dozen autonomous robots.Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Colloquia
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CS Colloquium - Reid Simmons
Tue, Jan 22, 2008 @ 03:30 PM - 05:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
TITLE:
Social Robots ABSTRACT:
As robots become more ubiquitous in society, they will have to learn to interact with people in socially acceptable ways. For the past six years,we have been developing techniques that enable robots to behave according to social conventions, both conversationally and spatially. The techniquesinvolve explicit modeling of human behavior and social conventions,probabilistic reasoning about situations and the intentions of people, and explicit representation of affect and mutual interaction. We have developed several robots that embody these ideas, including GRACE, a robot that attended the National Conference on Artificial Intelligence, the roboceptionist, a joint project with the School of Drama, and a robot that dances rhythmically with children. This talk will describe our efforts in this area, focusing on the techniques that we have developed and highlighting the gap that still remains between the behavior of our robotsand true social interaction. BIOGRAPHY:
Reid Simmons is a Research Professor in the School of Computer Science at Carnegie Mellon University. He earned his B.A. degree in 1979 in ComputerScience from SUNY at Buffalo, and his M.S. and Ph.D. degrees from MIT in 1983 and 1988, respectively, in the field of Artificial Intelligence. Since coming to Carnegie Mellon in 1988, Dr. Simmons' research has focusedon developing self-reliant robots that can autonomously operate over extended periods of time in unknown, unstructured environments. This work involves issues of robot control architectures, probabilistic planning and reasoning, monitoring and fault detection, and robust indoor and outdoornavigation. More recently, Dr. Simmons has focused on the areas of human-robot social interaction, coordination of multiple heterogeneous robots, and formal verification of autonomous systems. Over the years, he has been involved in the development of over a dozen autonomous robots.
Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Webmaster
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Modeling Critical Infrastructures with Networked Agent-based Approaches
Wed, Jan 23, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:
Dr. Robert J. Glass,
Distinguished Member of Technical Staff
Complex Adaptive Infrastructures and Behavioral Systems
National Infrastructure Simulation and Analysis Center
Sandia National LaboratoryCritical Infrastructures are formed by large numbers of components that interact within complex networks. As a rule, infrastructures contain strong feedbacks either explicitly through the action of hardware/software control, or implicitly through the action/reaction of people. Individual infrastructures influence others and grow, adapt, and thus evolve in response to their multifaceted physical, economic, cultural, and political environments. Simply put, critical infrastructures are complex adaptive systems.Our general approach to modeling such systems distills the system of interest to a network (or multiple networks) of nodes and connections with a set of tailored interaction rules (static to adaptive) for each. Combined with drives and dissipations we can evaluate how general features, such as network connectivity and interaction rules, or specific perturbations such as a hurricane, can influence system failure (often cascading failure) and the choice of mitigation strategy once a cascade begins. Examples will be drawn from recent work that applies our general approach to areas as diverse as community mitigation for pandemic influenza (e.g., bird flu), congestion and cascades in coupled large value payment systems (e.g., foreign exchange coupled US and Euro systems, trillions of $ per day), and hurricane induced perturbations to US petrochemical supply chains.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Active Control of Separated Flow
Wed, Jan 23, 2008 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
AEROSPACE & MECHANICAL ENGINEERING DEPARTMENT"Active Control of Separated Flow"Lou CattafestaAssociate ProfessorDepartment of Mechanical and Aerospace EngineeringUniversity of FloridaAbstract:Flow separation incurs a large amount of energy loss and limits the performance of many flow-related devices (e.g., airfoils, diffusers, etc.). Researchers have been trying to mitigate or eliminate flow separation for over a century because of its large potential payoff in practical applications. Numerous active separation control strategies have been attempted on civil and military aircraft and underwater vehicles with varying degrees of success. However, most of the active control approaches are open-loop in nature because of their simplicity but are often time-consuming and expensive. This talk discusses two novel adaptive feedback control approaches designed to reattach a massively separated flow over a NACA airfoil with minimal control effort using piezoelectric synthetic jet actuators and various sensors for feedback. One approach uses an adaptive feedback disturbance rejection algorithm in conjunction with a system identification algorithm to develop a reduced-order dynamical systems model between the actuator voltage and unsteady surface pressure signals. The objective of this feedback control scheme is to suppress the pressure fluctuations on the upper surface of the airfoil model, which results in reduced flow separation, increased lift, and reduced drag. A second approach leverages various flow instabilities in a nonlinear fashion to maximize the lift-to-drag ratio using a constrained optimization scheme – in this case using a static lift/drag balance for feedback. Detailed experiments are described to elucidate the baseline uncontrolled and controlled flow physics, and various technical challenges are addressed and discussed in detail.Biographical Information:Lou Cattafesta is currently an Associate Professor in the Department of Mechanical and Aerospace Engineering at the University of Florida. His primary research interests are active flow control and aeroacoustics. Prior to joining UF in 1999, he was a Senior Research Scientist at High Technology Corporation in Hampton, VA, where he was the group leader of the Experimental and Instrumentation Group. His research at NASA Langley focused on supersonic laminar flow control and pressure- and temperature-sensitive paint measurement techniques. At that time, he became involved in active control of flow-induced cavity oscillations, which provoked his current research interests in active flow control and aeroacoustics. More information regarding his research can be found at http://www.img.ufl.edu. Dr. Cattafesta has co-authored 4 papers that have received AIAA best conference paper awards and 6 US Patents and more than 100 journal and conferences papers. He is an Associate Fellow of AIAA and long-time member of the AIAA Fluid Dynamics Technical Committee.
Location: Seaver Science LIbrary Room 150
Audiences: Everyone Is Invited
Contact: April Mundy
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Exploring the Bio-Nano Interface for Recognition and Assembly of Electronic Materials
Thu, Jan 24, 2008 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Graduate SeminarbyDr. Jennifer N. ChaIBM Almaden Research Center
San Jose, CA Abstract: As nanoelectronic device features shrink towards a critical limit, new research directions have been sought to resolve the resultant technological issues in a cost-effective manner. The ability of Nature to synthesize and assemble materials with high fidelity and precision has provided a potential means of overcoming these formidable challenges. Over the past few years, there have been numerous and extensive efforts to both understand the biological mechanisms for building inorganic and organic architectures and use biological systems to assemble nanoscale materials. New applications of current genetic engineering techniques have also been developed to overcome the difficulties of interfacing biology with non-biological substrates, enabling the use of biomolecular systems for addressing particular challenges in nanoelectronics. The first part of this talk will highlight some of the mechanisms of biomineralization and will in particular focus on the way biosilicates are both synthesized and assembled in Nature. One of the inherent reasons to understand how inorganic materials are produced in living systems is that all of these processes occur under ambient conditions, even those materials that are produced industrially under high temperature and pressure or at extreme pH. I will describe the mechanism by which one biological organism synthesizes highly ordered silica structures at neutral pH and how one can apply these mechanisms to biomimetic approaches using synthetic block copolymers. The understanding of how to chemically control both nucleation and growth of oxides at the nanometer scale led to the synthesis of highly-ordered, two-dimensional nanopatterned ceramic thin films that were used as nanoscale etch masks for producing nanoparticles of phase change materials.A significant amount of research at IBM has also been devoted to exploring nanowires and single walled carbon nanotubes (CNTs) as alternatives to silicon technology. Despite the unique electronic and physical properties of CNTs, however, there exist numerous technological challenges; in particular, the production of entirely semiconducting CNTs of a single or narrow range of band-gaps. The second part of this talk will focus on our recent efforts at the use of DNA to disperse CNTs and bio-combinatorial libraries to discover unique amino acid sequences that can bind a subset of dispersed CNTs. Specific biomolecular recognition of particular nanomaterials that demonstrate unique physical characteristics may impact applications ranging from nanoelectronics to nanomedicine. Thursday, January 24, 2008
Seminar at 12:45 p.m.
OHE 122
The Scientific Community is Cordially Invited.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce Sapir
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A Multiscale Characterization and Analysis Methodology for Ductile Fracture in Heterogeneous Metalli
Thu, Jan 24, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Somnath Ghosh,Department of Mechanical Engineering, Ohio State UniversityHeterogeneous metallic materials e.g. cast aluminum alloys or metal matrix composites are widely used in automotive, aerospace, nuclear and other engineering systems. The presence of precipitates and particulates in the microstructure often affect their failure properties like fracture toughness or ductility in an adverse manner. Important micromechanical damage modes that are responsible for deterring the overall properties include particulate fragmentation, debonding at interfaces and ductile matrix failure due to void initiation, growth and coalescence, culminating in local ductile failure. The complex interaction between competing damage modes in the presence of multiple phases makes failure and ductility prediction for these materials quite challenging. While phenomenological and straightforward micromechanics models have predicted stress-strain behavior and strength of multi-phase materials with reasonable accuracy, their competence in predicting ductility and strain-to-failure, which depends on the extreme values of distribution, is far from mature. To address the needs of a robust methodology for ductility, the work will discuss a comprehensive multi-scale characterization based domain decomposition method followed by a multi-scale model for deformation and ductile failure. Adaptive multi-scale models are developed for quantitative predictions at critical length scales, establishing functional links between microstructure and response, and following the path of failure from initiation to rupture. The work is divided into three modules. (i) Multi-scale morphology based domain partitioning to develop a pre-processor for multiscale modeling, (ii) Enriched Voronoi Cell FEM for particle and matrix cracking leading to ductile fracture and (iii) Macroscopic homogenization continuum damage model for ductile fracture. Finally a robust framework for two-way multi-scale analysis module is the coupling of different with different inter-scale transfer operators and interfaces is developed.Bio-SketchDr. Somnath Ghosh is the John B. Nordholt Professor in the Department of Mechanical Engineering at the Ohio State University. He received his M.S. in Theoretical and Applied Mechanics from Cornell University and PhD from the University of Michigan. His research interests include multiple scale modeling in spatial and temporal domains, failure and fatigue modeling in heterogeneous materials and structures, Computational nanotechnology, etc. He is a fellow of American Association for the Advancement of Science (2008), US Association of Computational Mechanics (2007), ASM International (2006) and ASME (2002). In 2007, the Ohio State University awarded him the University Distinguished Scholar award. He got the National Science Foundation Young Investigator award of NSF in 1994. He was an elected member of the executive council of the US Association of Computational Mechanics (USACM) from 2002-2006 and is the Chair of USACM’s Materials Modeling committee. The US Association of Computational Mechanics has chosen him to be the organizer of the 10th US National Congress of Computational Mechanics in 2009.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Honors Colloquium Lecture
Fri, Jan 25, 2008 @ 01:00 PM - 01:50 PM
Viterbi School of Engineering Student Affairs
Conferences, Lectures, & Seminars
Lecture offered by Mr. Arnab Chanda Director of US Equity Research on Semiconductors for the Deutsche Bank
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Honors Program Students and all Faculty and Staff are invited to attend
Contact: Erika Chua
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Routing and Network Coding on Lines, Stars, and Rings
Fri, Jan 25, 2008 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Dr. Gerhard Kramer, Bell Laboratories,
Alcatel-LucentABSTRACT: Network coding allows each node in a network to combine its input information instead of simply storing, copying, and forwarding data. We present several recent results. The first is a new upper bound on network coding rates that applies to wireline, wireless, and mixed wireline/wireless networks. The bound, called a progressive d-separating edge set (or PdE) bound, involves progressively removing edges from a network graph and checking whether certain strengthened d-separation conditions are satisfied. Second, we consider line networks that are elements of larger networks. We show that under both edge and node capacity constraints the optimal code is a combination of rate-splitting, copying, routing, and "butterfly" binary linear network coding. Third, we consider star and ring networks and develop related results.This work was done jointly with Sadegh Tabatabaei and Serap A. Savari.BIO: Gerhard Kramer received the B.Sc. and M.Sc. degrees in electrical engineering from the University of Manitoba, Winnipeg, MB, Canada, in1991 and 1992, respectively, and the Dr. sc. techn. (Doktor der Technischen Wissenschaften) degree from the Swiss Federal Institute of Technology (ETH), Zurich, Switzerland, in 1998. 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, Alcatel-Lucent, Murray Hill, NJ, USA.HOST: Prof. Giuseppe Caire, caire@usc.eduLocation: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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BME 533 Seminar :Daniel Kamei, Asst. Professor of Bioengineering, UCLA
Mon, Jan 28, 2008 @ 12:30 PM - 01:50 PM
Alfred E. Mann Department of Biomedical Engineering
Conferences, Lectures, & Seminars
Topic: Designing Drug Delivery Vehicles by Engineering Trafficking Pathways"
Audiences: Department Only
Contact: Mischalgrace Diasanta
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BME 533 Seminar: Daniel Kamei, Asst. Professor of Bioengineering, UCLA
Mon, Jan 28, 2008 @ 12:30 PM - 01:50 PM
Alfred E. Mann Department of Biomedical Engineering
Conferences, Lectures, & Seminars
Topic: Designing Drug Delivery Vehicles by Engineering Trafficking Pathways"
Audiences: Department Only
Contact: Mischalgrace Diasanta
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Pulsed-laser processing of ferromagnetic semiconductors
Tue, Jan 29, 2008 @ 01:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Graduate SeminarbyOscar D. Dubón, Jr.Department of Materials Science and Engineering
University of California Berkeley and Lawrence Berkeley National Laboratory
Berkley, CAAbstract:Because of their unique combination of magnetic and semiconducting properties and their potential as both injection sources and filters for spin-polarized carriers, ferromagnetic semiconductors have attracted much attention for spin-based electronics, or spintronics. These novel materials are formed by the substitution of a relatively small fraction of host atoms—a few atomic percent—with a magnetic species such as Mn. In the prototypical ferromagnetic semiconductor Ga1-xMnxAs, inter-Mn exchange is known to be mediated by holes in extended or weakly localized states; however, the fundamental nature of exchange across the Ga-Mn-pnictide series is less clear. Unfortunately, challenges in materials synthesis have obstructed both the further understanding of these materials and their application in practical devices. Even the relatively low alloying levels necessary for ferromagnetism require the application of non-equilibrium growth strategies, in particular low-temperature molecular beam epitaxy (LT-MBE).At Berkeley we have undertaken investigations on the synthesis of ferromagnetic semiconductors using a combination of Mn ion implantation and pulsed-laser melting (II-PLM). By this simple process we have produced epitaxial, single crystalline films of ferromagnetic GaxMn1-xAs. These epilayers display the essential magnetic and electrical properties observed in films grown by LT-MBE. We have used II-PLM to produce new Ga-Mn-pnictide alloys including ferromagnetic Ga1-xMnxP. This material represents an intriguing system in which strongly localized carriers in a detached impurity band stabilize ferromagnetism. The possibility of introducing more than one species by ion implantation into a semiconductor host opens further opportunities to study quaternary alloys and probe chemical trend in the ferromagnetic Curie temperature. I will present results from our studies of these novel ferromagnetic semiconductors as well as efforts to develop laser patterning techniques for the realization of planar spintronic structures.Tuesday, January 29, 2008
Seminar at 1:00p.m.
OHE 122
The Scientific Community is Cordially Invited
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce Sapir
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Torsional Effects on the Inelastic Seismic Response of Structures
Tue, Jan 29, 2008 @ 01:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Oral Defense by: Mehran Mansuri,
Sonny Astani Department of Civil and Environmental EngineeringABSTRACT:
To evaluate inelastic torsional response of buildings due to different parameters such as unsymmetrical distribution of mass or lateral load resisting elements in the plan of the structure or yielding and inelastic behavior of resisting elements and loss of the resistance of such an element during an earthquake, a full three-dimensional nonlinear dynamic analysis is a powerful tool to evaluate such a nonlinear response.
The results of nonlinear dynamic analyses of two actual steel moment frame buildings that were damaged during the 1994 Northridge earthquake subjected to couple of different recorded ground motions from Northridge and Loma Prieta earthquakes are presented and the importance of different parameters such as discontinuity of lateral resisting elements, unsymmetrical distribution of mass or resistance in the plan of structure, intensity and frequency content of earthquake ground motions, accidental eccentricity as prescribed by code and the effect of geometric nonlinearity (P-Delta) on the inelastic lateral-torsional response of structures is discussed. Response parameters considered include lateral story displacement, Interstory drift index, plastic hinge rotation demand and torsional rotation of each floor.
The analysis procedures use three-dimensional nonlinear dynamic analytical models developed for the PERFORM 3-D computer program.
Study of the results for different models with different eccentricities clearly shows the effect of inelastic torsion in comparison with elastic torsion on the response of structures. The torsional rotation of floors considered as a main parameter of torsional response of the building has an average increase of 30 to 60 percent for material nonlinearity. By adding geometric nonlinearity (P-Delta), this increases 70 to 100 percent of elastic torsional rotation. This clearly shows the inelastic torsional response of structures may be significantly underestimated by a linear dynamic analysis, especially for large value of mass or stiffness eccentricity and intensity of the ground motion.
Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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CS Colloquia: Approximation algorithms for combinatorial allocation problems
Tue, Jan 29, 2008 @ 03:30 PM - 05:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Title: Approximation algorithms for combinatorial allocation problemsSpeaker: Dr. Jan Vondrak (Princeton)ABSTRACT:
Combinatorial allocation problems arise in situations where a set of items
should be distributed among n players in order to maximize a certain social
utility function. Such problems have been subject to recent interest due to
their applications in combinatorial auctions and electronic commerce. Since
allocation problems are typically NP-hard to solve optimally, we seek
approximation algorithms that find a solution of value at least c * OPT where
OPT is the optimum and cA particular case of interest is the Submodular Welfare Problem where utility
functions are assumed to be monotone and submodular. It has been known since
1978 that a greedy algorithm gives a 1/2-approximation [Nemhauser, Wolsey,
Fisher] for a more general problem of submodular maximization subject to a
matroid constraint. I will show how this can be improved to a
(1-1/e)-approximation - an approximation factor which is known to be optimal.
A new technique that we use is the approximate solution of a non-linear
optimization problem using a "continuous greedy algorithm".(partly joint work with G. Calinescu, C. Chekuri and M. Pal)BIO:
I grew up in the Czech republic and I got a Master's degree in computer
science from Charles University in Prague. Then I went to grad school at MIT
where I got a PhD in applied math in 2005. My advisor was Michel Goemans. I
spent a year as a postdoc at Microsoft Reserch (2005-06) and currently I'm a
postdoc at Princeton University.
~Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Colloquia
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Approximation algorithms for combinatorial allocation problems
Tue, Jan 29, 2008 @ 03:30 PM - 05:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
ABSTRACT:
Combinatorial allocation problems arise in situations where a set of items should be distributed among n players in order to maximize a certain social utility function. Such problems have been subject to recent interest due to their applications in combinatorial auctions and electronic commerce. Since allocation problems are typically NP-hard to solve optimally, we seek approximation algorithms that find a solution of value at least c * OPT where OPT is the optimum and cA particular case of interest is the Submodular Welfare Problem where utility functions are assumed to be monotone and submodular. It has been known since
1978 that a greedy algorithm gives a 1/2-approximation [Nemhauser, Wolsey, Fisher] for a more general problem of submodular maximization subject to a matroid constraint. I will show how this can be improved to a (1-1/e)-approximation - an approximation factor which is known to be optimal.
A new technique that we use is the approximate solution of a non-linear optimization problem using a "continuous greedy algorithm".(partly joint work with G. Calinescu, C. Chekuri and M. Pal)BIO:
I grew up in the Czech republic and I got a Master's degree in computer science from Charles University in Prague. Then I went to grad school at MIT where I got a PhD in applied math in 2005. My advisor was Michel Goemans. I spent a year as a postdoc at Microsoft Reserch (2005-06) and currently I'm a postdoc at Princeton University.
Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: CS Front Desk
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Equation-Free Modeling and Computation for Complex/Multiscale Systems
Wed, Jan 30, 2008 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker: Dr. Yannis Kevrekidis,
Princeton University"Equation-Free Modeling and Computation for Complex/Multiscale Systems"In current modeling practice for complex/multiscale systems, the best available descriptions often come at a fine level (atomistic, stochastic, microscopic, individual-based) while the questions asked and the tasks required by the modeler (prediction, parametric analysis, optimization and control) are at a much coarser, averaged, macroscopic level. Traditional modeling approaches start by first deriving macroscopic evolution equations from the microscopic models, and then bringing our arsenal of mathematical and algorithmic tools to bear on these macroscopic descriptions. Over the last few years, and with several collaborators, we have developed and validated a mathematically inspired, computational enabling technology that allows the modeler to perform macroscopic tasks acting on the microscopic models directly. We call this the "equation-free" approach, since it circumvents the
step of obtaining accurate macroscopic descriptions. We will argue that the backbone of this approach is the design of (computational) experiments. Traditional continuum numerical algorithms can thus viewed as protocols for experimental design (where "experiment" means a computational experiment set up and performed with a model at a different level of description). Ultimately, what makes it all possible is the ability to initialize computational experiments at will. Short bursts of appropriately initialized computational experimentation through matrix-free numerical analysis and systems theory tools like variance reduction and estimation- bridge microscopic simulation with macroscopic modeling. I will also discuss some recent developments in data mining algorithms, exploring large complex data sets to find good "reduction coordinates".Location: Kaprielian Hall (KAP) - 209
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Mitigating Attacks in Unstructured Multicast Overlay Networks
Wed, Jan 30, 2008 @ 02:00 PM - 03:30 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Abstract:Many multicast overlay networks maintain application-specific performance goals by dynamically adapting the overlay structure when the monitored performance becomes inadequate. This adaptation results in an unstructured overlay where no neighbor selection constraints are imposed. Although such networks provide resilience to benign failures, they are susceptible to attacks conducted by adversaries that compromise overlay nodes. Previous defense solutions proposed to address attacks against overlay networks rely on strong organizational constraints and are not effective for unstructured overlays.We identify, demonstrate and mitigate insider attacks against measurement-based adaptation mechanisms in unstructured multicast overlay networks. We propose techniques to decrease the number of incorrect adaptations by using outlier detection and limit the impact of malicious nodes by aggregating local information to derive global reputation for each node. We demonstrate the attacks and mitigation techniques through Internet deployments of a mature overlay multicast system.In addition, we also show how the mitigation techniques we have developed effectively improve the resilience of virtual coordinate systems. Virtual coordinate systems allow hosts on the Internet to determine the latency to arbitrary hosts without actively monitoring all nodes in the network and are used to optimize overlay construction and maintenance. We demonstrate the attacks and mitigation techniques in the context of a well-known distributed virtual coordinate system using simulations based on three representative, real-life Internet topologies of hosts and corresponding round trip times (RTT).Bio:Cristina Nita-Rotaru is an Assistant Professor in the Department of Computer Science at Purdue University where she established the Dependable and Secure Distributed Systems Laboratory. Her research interests lie in designing distributed systems, network protocols and applications that are dependable and secure, while maintaining acceptable levels of performance. Current research focuses on: designing intrusion-tolerant architectures for distributed services that scale to wide-area networks, studying attacks and defenses in overlay networks, investigating survivable routing in wireless ad hoc networks, and designing group services for wireless mesh networks.Cristina Nita-Rotaru is a recipient of the NSF Career Award in 2006 and a recipient of the Purdue Teaching for Tomorrow Award in 2007. She has served on the Technical Program Committee of numerous conferences in security, dependability, networking and distributed systems. Her work is funded by the Center for Education and Research in Information Security and Assurance (CERIAS), by the Defense Advanced Research Projects Agency (DARPA), and by the National Science Foundation (NSF).
Location: USC-ISI, Marina del Rey, CA 90292, 111th Fl.,POC: Joe Kemp (310) 448.9171
Audiences: Everyone Is Invited
Contact: CS Front Desk
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Frontiers in Engineering Education and Research in the 21st Century
Thu, Jan 31, 2008 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Distinguished Lecture SeriesProfessor Venky NarayanamurtiDean, School of Engineering and Applied Sciences
Harvard UniversityAbsractIn our rapidly transforming world, engineering plays an ever more central role,
especially in advancing basic science, creating tools and everyday technologies, driving
economic development and meeting societal challenges in areas from energy to
environment to human health.
In this talk I will examine the changing role of engineering and engineering
research and education to address the great societal challenges of the 21st century. I will
discuss the need for educating broadly trained engineers who understand not only how
thinks work but also how the world works. Such engineers will have broad knowledge
of various disciplines and understand the enormous value of integrative thinking in
addition to reductionist thinking. They will need to be flexible and adaptable and be
able to function in a global marketplace. Such "renaissance engineers" will play a key
leadership role in the emerging knowledge economy.
I will also spend time discussing emerging science and technological frontiers to
address societal problems alluded to earlier. Translating research discoveries into
practice is a key challenge for engineering schools and industrial R & D laboratories.
The need for developing new models for university-industry collaboration and to
develop the appropriate intellectual capital will be discussed.Thursday, January 31, 2008Seminar at 12:45 p.m. in OHE 122Refreshments served after the seminar in HED LobbyThe Scientific Community is Cordially Invited.Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce Sapir
