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SUNMONTUEWEDTHUFRISAT
Conferences, Lectures, & Seminars
Events for September
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Characterization of nanoparticles and colloids in aquatic systems:
Fri, Sep 01, 2006 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Mamadou S. Diallo, Ph.D.Materials and Process Simulation Center, Beckman Institute 139-74
California Institute of Technology, Pasadena, CA, 91125
and
Department of Civil Engineering
Howard University, Washington DC, 20059Abstract:
Fulvic acids (FA) and humic acids (HA) constitute 30 to 50% of dissolved organic matter in natural aquatic systems. A commonly accepted view in the environmental chemistry literature is that FA and HA exist as soluble macroligands in aqueous solutions at low concentration and as supramolecular aggregates at higher concentration. The size, shape and structure of these aggregates are still the subject of ongoing debate. In this paper, we use small angle neutron scattering (SANS) to assess the effects of solute concentration, solution pH and background electrolyte (NaCl) concentration on the structure and size of Suwannee River fulvic acid (SRFA) aggregates in aqueous solutions. The qualitative features of the SANS curves and data analysis are not consistent with the view points that FA and HA form micelle-like aggregates or random coils in aqueous solutions. We find that SRFA forms fractal aggregates in aqueous solutions with size greater than 242 nm. The SRFA aggregates undergo a significant degree of restructuring in compactness as solution pH, solute concentration and NaCl concentration increase.Location: Kaprielian Hall (KAP) - rielian Hall, Room 156
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Aerospace Engineering Today and Tomorrow
Fri, Sep 01, 2006 @ 01:00 PM - 02:00 PM
Viterbi School of Engineering Student Affairs
Conferences, Lectures, & Seminars
Engineering Honors Colloquium lecture given by Mr. Robert Villanueva of Boeing Company.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Faculty and Honors Program Students
Contact: Erika Chua
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Material Science Seminar
Fri, Sep 01, 2006 @ 02:30 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Daniel R. MerrillDirector of Applications Engineering
Alfred E. Mann Foundation for Scientific ResearchSanta Clarita, CA 91355 Increased Electrode Impedance as a Mechanism of Recording Instability Abstract The mechanisms underlying performance degradation of chronically implanted silicon microelectrode arrays in the central nervous system (CNS) remain unclear. One proposed mechanism is increased electrical impedance due to the foreign body reaction at the electrode-brain tissue interface. In this seminar I will first discuss some of the technical issues of impedance measurement including procedural issues that are often poorly understood and implemented. Next I will present experimental work directed towards understanding the failure mechanisms of chronically implanted devices. Several components of the foreign body response were evaluated to determine whether their presence correlates with increased electrical impedance that may be a factor in loss of device performance. Iridium oxide microelectrode recording arrays were electrically characterized in vitro in the presence of saline, culture media with 10% fetal bovine serum (FBS), and coated with various CNS cell types isolated from young Sprague-Dawley rats. Electrochemical impedance spectroscopy (EIS) and cyclic voltammetry (CV) were performed using a three-electrode system. Microelectrodes coated with various cell types known to participate in the foreign body response caused a significant increase in impedance immediately after seeding on the order of 50%, and this value remained constant or gradually increased for up to several weeks. These findings indicate that the attachment of various molecular and cellular species likely contribute to increases in electrical impedance following implantation in brain tissue, but do not appear sufficient to hinder recording performance. These data further suggest that designers may consider incorporation of adherent cells on implanted microelectrodes to promote integration, improve tissue response or deliver therapeutic agents to adjacent tissue. I will lastly present preliminary results of in vivo impedance measurements using a novel tool for characterizing temporal changes at the electrode-brain tissue interface. September 1st, 20062:30-3:50 PM(Refreshments will be served at 2:15 PM)SLH 102**All first year materials science majors are required to attend**Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Correlation Coefficients among Some Statistics Used for Signal Detection
Thu, Sep 07, 2006 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Prof. Jinsoo Bae, Sejong UniversityABSTRACT: In this talk, we address the derivation of joint distributions and correlation coefficients for seven pairs of statistics used commonly in a number of signal detection schemes. The upper and lower bounds of the correlation coefficients are obtained, and relationships among the correlation coefficients are derived. Explicit values of the correlation coefficients evaluated for some specific noise distributions are shown for easy reference.BIO: Jinsoo Bae graduated from Gyeong Gi High School of Science, Suwon, Korea, one year earlier than normal with an honor, in 1990. He received the B.S.E. (summa cum laude), M.S.E., and Ph.D. degrees in electrical engineering from Korea Advanced Institute of Science and Technology (KAIST) in 1993, 1995, and 1998, respectively. From January 1997 to December 1997, he was a Visiting Researcher with the Department of Electrical Engineering, the University of Tokyo, Tokyo, Japan. From January 1998 to February 2000, he was also with Accenture, Motorola Japan Ltd., and LG Telecom Ltd., before he joined the Department of Information and Communication Engineering, Sejong University, Seoul, Korea, in March 2000, where he is currently an Associate Professor. He has coauthored Advanced Theory of Signal Detection (Springer, 2002) and has published a number of papers on nonparametric signal detection. He is also a Senior Member of IEEE (Institute of Electrical and Electronics Engineers) and a Member of Korean Institute of Communication Sciences (KICS) and Institute of Electronics, Information, and Communication Engineers (IEICE). His research interests include signal detection theory and digital signal processing.HOST: Prof. Urbashi Mitra, ubli@usc.edu
Location: Hughes Aircraft Electrical Engineering Center (EEB) - -248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Passive in situ samplers for dissolved and sediment-associated organic contaminants
Fri, Sep 08, 2006 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speakers:Keith A. Maruya
Southern California Coastal Water Research Project (SCCWRP), 7171 Fenwick Lane, Westminster, CA 92683 USA (keithm@sccwrp.org)
Ze-Yu Yang
State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, ChinaCoastal waterways draining highly urbanized landscapes serve as conduits of potentially toxic pollutants such as polycyclic aromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs) and chlorinated pesticides (e.g. DDTs and chlordanes) to the receiving estuarine/marine environment. Decades long discharge has resulted in contaminant accumulation in nearshore environments such as bays, harbors, marinas and rivermouths, impacting sediment and water quality. Because these compounds have very low aqueous solubility and current measurement technology is not cost-effective, however, little or no data for aqueous concentrations in situ exist, making the determination of loadings (e.g. Total Maximum Daily Loads or TMDLs) difficult at best. Recently developed passive samplers based on solid phase microextraction (SPME) technology and sorption to polyethylene (polyethylene devices or PEDs), however, have made it possible to quantify ultra-trace levels of pollutants in situ at a fraction of the cost and with a much quicker turnaround time than traditional techniques. Disadvantages associated with these passive sampling alternatives, however, are the extended time to reach equilibrium in situ as well as the degree of pre-deployment calibration required to determine equilibrium partitioning parameters. Over the past several years, SCCWRP and CAS have collaborated in cataloguing SPME parameters for a large number of organic analytes, including most organic contaminants that are currently being considered for regulation. A new collaboration between SCCWRP and LMU will calibrate PEDs for selected TMDL regulated organics, and in a subsequent phase, compare the performance of SPME and PED samplers under controlled lab and field conditions.Location: Kaprielian Hall (KAP) - rielian Hall, Room 156
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Simulation in Surgery
Fri, Sep 08, 2006 @ 01:00 PM - 02:00 PM
Viterbi School of Engineering Student Affairs
Conferences, Lectures, & Seminars
Engineering Honors Colloquium lecture given by Dr. Shirin Towfigh, Assistant Professor of Surgery at the University of Southern California.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Faculty and Honors Program Students
Contact: Erika Chua
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Material Science Seminar
Fri, Sep 08, 2006 @ 02:30 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
From Electrons To Finite Elements: A Concurrent Multiscale Approach For Metalsby
Gang LuDepartment of Physics, California State University, Northridge, CA 91330-8268In this talk, I will discuss how multiscale modeling can be applied to study (1) Hydrogen
enhanced local plasticity in Al, which is crucial to understanding of H embrittlement of
metals. The atomic and electronic mechanism for enhanced dislocation mobility is
explored; (2) Ductile fracture in Al under mode I loading. The atomistic mechanisms of
dislocation nucleation from the crack tip, and crack propagation are investigated. The
electronic states at the crack tip during the fracture process are examined in detail.
Multiscale modeling of material properties has emerged as one of the grand challenges in
materials science and engineering. Multiscale modeling is necessary because the
macroscopic properties of materials are largely determined by the microscopic processes,
taken place particularly at lattice defects. A typical example is the mechanical response of
metals to external loads, which is characterized as ductile or brittle at the macroscopic
scale, depending on the ability of the material to absorb the load by plastic deformations.
This response can be drastically altered by the presence of impurities and their influence
on bonding between the atoms in crucial regions like the crack tip and dislocation core.
The delocalized nature of electronic states in a metal makes the description of such
effects particularly challenging. We have recently developed a multiscale modeling
approach that concurrently couples quantum mechanical calculations for electrons, to
empirical atomistic simulations for classical atoms, and to continuum mechanical
modeling for finite elements, in a unified description [1]. In specific, the electronic
structure calculations are performed with the plane-wave pseudopotential method based
on the density-functional theory (DFT), the classical atomistic simulations with the
embedded-atom method (EAM), and the continuum modeling with the Cauchy-Born rule
in the local Quasicontinuum (QC) formulation [2]. The multiscale method is
implemented in the context of the QC framework with the additional capability to include
DFT calculations for a selection of non-local QC atoms. A novel coupling scheme has
been developed to combine the DFT and EAM calculations [3] in a seamless fashion to
deal with non-local QC atoms.
Reference:
[1] G. Lu, E.B. Tadmor, and E. Kaxiras, Phys. Rev. B 73, 024108 (2006).
[2] E.B. Tadmor, M. Ortiz, and R. Phillips, Philos. Mag. A 73, 1529 (1996).
[3] N. Choly, G. Lu, W. E and E. Kaxiras, Phys. Rev. B 71, 094101 (2005).Refreshments served at 2:15All MASC first-year students are required to attendLocation: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Integrated Multi-disciplinary Systems Research for Hazard Mitigation
Tue, Sep 12, 2006 @ 11:00 AM - 12:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Faculty are invited to lunch at the University Club following the presentation. Please RSVP to Georgia Lum ext. 0-4885Speaker: Dr. Vilas Mujumdar, P.E., S.E.Earthquake Engineering Research Center Cluster Leader and ERC Program Director
Division of Engineering Education and Centers
National Science FoundationVilas Mujumdar is the Program Director responsible for oversight of 3 Earthquake Engineering Research Centers, and coordination of earthquake engineering integrated multidisciplinary research with other divisions of NSF. He manages the review and recommendation process for establishing new Engineering Research Centers in Civil Infrastructure and also coordinates public policy research for various Engineering Research Centers.After 25 years in private industry serving in various executive positions including CEO, Dr. Mujumdar joined the State of California, serving for 9 years as Chief of Operations with the Division of the State Architect. He received numerous awards for his work and many of his projects have been featured in publications such as Engineering News Record.Dr. Mujumdar is a registered Civil Engineer and Structural Engineer in California and is a professional engineer in many other states. He holds Bachelor of Science and Master of Science degrees in Civil Engineering, a Master of Business Administration and a doctorate in Public Administration specializing in seismic risk. He is a Fellow of American Concrete Institute, American Society of Civil Engineers, The Prestressed Concrete Institute, and The Institution of Structural Engineers (UK). He has served on and chaired numerous committees of ASCE, ACI, SEAOC, TMS and BSSC.Location: Ronald Tutor Hall (RTH) Room 306
Audiences: Epstein ISE, CE, and SPPD faculty and Graduate Students, CREATE researchers
Contact: Linda Mizushima
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Some New Variance Reduction Ideas in Simulation
Tue, Sep 12, 2006 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Prof. Sheldon Ross, University of Southern CaliforniaABSTRACT: Building on the idea of stratified sampling we present an extension that is useful in analyzing simulation problems related to 1. systems having Poisson arrivals;2. monotone systems of Bernoulli data;3. systems of conditionally Poisson data;4. computing monotone functions of random numbersBIO: Sheldon M. Ross is a professor in the Department of Industrial Engineering and Operations Research at the University of
Southern California. He received his Ph.D. in statistics at Stanford University in 1968. He has published many technical
articles and textbooks in the areas of statistics and applied probability. Among his texts are A First Course in Probability,
Introduction to Probability Models, Stochastic Processes, and Introductory Statistics. Professor Ross is the founding and
continuing editor of the journal Probability in the Engineering and Informational Sciences. He is a Fellow of the Institute
of Mathematical Statistics, and a recipient of the Humboldt US Senior Scientist Award.
Author of: Statistical Aspects of Quality Control, Introduction to Stochastic Dynamic Programming, Probability Models for Computer Science, Introduction to Probability and Statistics for Engineers and Scientists,
Introduction to Probability Models,
Introductory Statistics,
Introduction to Probability Models, ISE, Simulation,
Introduction to Probability Models,
Student Solutions Manual for Introductory Statistics.Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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A Physical Approach to Stochastic Dynamics
Wed, Sep 13, 2006 @ 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Jie Li
Cheung Kong Scholar Professor, Tongji University
Shanghai, P. R. ChinaAbstract: Where is the source of randomness? How to model a stochastic process? In the trodational Stochastic Dynamics, there exist a number of unresolved problems. In this presentation, the author tries to give a new physical approach to stochastic dynamics. By introducing stochastic modeling principle, we have got new models for earthquake ground motions and wind speed process, two kind of typical stochastic process. From these examples, it may be found that by introducing physical relationship into a stochastic system, the source of randomness would be revealed. And by introducing physical relationship, the essential relationship between the deterministic systems and the stochastic systems can be revealed as well. This will supply a new way to approach a series of hard problems, such as analysis of nonlinear stochastic systems, the reliability assessment of dynamical systems and the control of nonlinear stochastic systems. Furthermore, the above viewpoints show that, in the research on a objective reality, not only need to deal with the relationship among the physical phenomenon, but also need to investigate the transmit process of randomness.
Location: Kaprielian Hall (KAP) - 203
Audiences: Everyone Is Invited
Contact: Linda Mizushima
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Lyman L. Handy Colloquium
Thu, Sep 14, 2006 @ 12:45 PM - 02:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
"Opportunities and Challenges in Nanostructured Materials"Professor Jagdish (Jay) Narayan
Department of Materials Science and Engineering
North Carolina State University
Raleigh, NC ABSTRACT
This talk addresses some of the fundamental issues and critical advantages in reducing the grain size/ feature size to the nanoscale regime. We find that as the grain size or feature size is reduced, there is a critical size below which the defect content can be frozen or reduced virtually to zero. This critical size for most defects in materials falls in the nanoscale regime. Thus, nanostructured materials offer a unique opportunity to realize the property of a perfect material. However, with this opportunity comes a great challenge in terms of engineering a large fraction of atoms near the surfaces/interfaces. Another challenge is to self-assemble nanounits with desired structure and orientation with respect to the matrix. This often requires thin film epitaxy across the misfit scale with lattice misfit ranging from about 1% to 50%. Using a new paradigm of domain matching epitaxy (DME), we are able to deal with thin film epitaxy across the misfit scale within the continuum ground state energy description of the strained system. The DME framework is based upon matching of integral multiples of lattice planes, where there is one dislocation in each domain corresponding to missing (compressive strain) or extra (tensile strain) half plane. According to the DME paradigm, 2.0% and 25% misfits correspond to 49/50 and 3/4 planar matching, respectively. The misfit in between the integral multiples of planes is accommodated by the principle of domain variation. The limiting factors in DME are associated with matching of interface interatomic potentials, lattice relaxation, overlapping of dislocation cores and bending of lattice planes. For large misfit systems, strain free energy often dominates over chemical free energy. We focus on integration of systems based on III-nitrides, II-oxides, and perovskites.Thursday, September 14, 2006
12:45 p.m.
OHE 122
Refreshments will be served after the seminar in the HED Lobby
The Scientific Community is cordially invited.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce
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SOURCE APPORTIONMENT OF PAHS IN SEDIMENTS USING FACTOR ANALYSIS BY TIME RECORDS
Fri, Sep 15, 2006 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
SOURCE APPORTIONMENT OF PAHS IN SEDIMENTS
USING FACTOR ANALYSIS BY TIME RECORDS:
APPLICATION TO LAKE MICHIGAN, U.S.ASpeakers:Dr. Erik R. Christensen
Department of Civil Engineering and Mechanics,
University of Wisconsin-Milwaukee, Milwaukee, WI 53201, USAABSTRACTApportionment of sources of polycyclic aromatic hydrocarbons (PAHs) by a factor analysis model based on time records for-seven sediment cores from central Lake Michigan is reconsidered to provide a more quantitative treatment, and one additional factor (source). The effect of mixing depth was observed on the unmixed fluxes, and a computer program was developed for estimation of the average P AH fluxes from the reconstructed P AH records. The new factor analysis model with nonnegative constraints includes not only scaling but also back scaling which improved the source apportionment significantly. One core, CLM-A, was an outlier and was omitted from the analysis. Wood Burning was identified as a third major source of PAHs in the area (20% of the total PAH flux). The other two sources petroleum (traffic), 45%, and coal (coke oven emissions), 35%, became more apparent, where the contributions are based on the sum of concentrations of sixteen PAH compounds. A reduced mixing depth (1.0 - 1.5 cm) was found to be more appropriate than the originally estimated mixing depth (1.5 - 2.0 cm).Location: Kaprielian Hall (KAP) - rielian Hall, Room 156
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Honors Program Colloquium: How to Market a Major Motion Picture
Fri, Sep 15, 2006 @ 01:00 PM - 02:00 PM
Viterbi School of Engineering Student Affairs
Conferences, Lectures, & Seminars
Engineering Honors Colloquium lecture given by Mr. George Bloom, director at Vision Mixer Films and former Vice President of Special Operations of Theatrical Marketing at 20th Century Fox.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Faculty and Honors Program Students
Contact: Erika Chua
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Material Science Seminar
Fri, Sep 15, 2006 @ 02:30 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Dr Matthew Halsall,
School of Electrical and Electronic Engineering,
The University of Manchester,
UK.Visible and Infrared spectroscopy of nitride quantum wells and dotsABSTRACTThe speaker will describe some his recent research concerning the optical properties of semiconductor quantum wells and dots based on the wide gap Al/Ga/In nitride materials. Indium rich InGaN quantum dots have been grown on GaN by MOVPE and studied by AFM. The dots occur at low surface densities, are typically 20-30nm in diameter and 5nm in height, and they also have tendency to occur in closely spaced pairs. Macro and micro photoluminescence studies of these dots show emission due to the dots in the 2.5-2.9eV region of the spectrum and the presence of sharp spectral lines demonstrates the 1D nature of their electronic energy levels. The dot PL linewidth also show the effects of spectral diffusion due to the charging of defect levels in the underlying "wetting layer". The use of Schottky junctions to deplete the impurity levels and reduce this linewidth is discussed. After depletion in this way, the power dependent PL of individual dots reveals a complex energy spectrum dominated by the internal fields present in these wurtzite systems. Finally some recent results on near/mid infrared intersuband structures grown in the AlGaN/GaN system will be presented. These include first mid-infrared Quantum well infrared photoresponse in the 2-5micron region of the spectrum from a device fabricated in this system.September 15th, 2006
2:30-3:50 PM
(Refreshments will be served at 2:15 PM)
SLH 102**All first year materials science majors are required to attend**
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Reducing the Complexity of Graphical Models via Cycles
Tue, Sep 19, 2006 @ 03:30 PM - 04:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Mr. Thomas R. Halford, Communication Sciences Institute, University of Southern CaliforniaABSTRACT: A decade ago, the introduction of turbo codes and iterative message passing algorithms revolutionized the theory and practice of coding. In the ensuing years, the coding theory community has become adept at designing codes from good graphical models - that is, models which imply low-complexity, near-optimal iterative message passing algorithms. Specifically, modern codes are constructed by connecting a large number of simple local codes together via a rich, random-like, cyclic interconnection network. A key observation from this work is that the introduction of cycles to graphical models can enable massive complexity reductions in model, and thus decoding, complexity.Whereas constructive graphical modeling problems (e.g. code design) have been widely addressed by the coding theory community, less is understood about the inverse problem of model extraction. Specifically, can good graphical models be obtained for existing algebraic codes, or more generally, for arbitrary systems? What tradeoffs exist between model complexity and cyclic topology for a given code? If good models can exist, how can they be obtained, or extracted? This talk presents a theoretical framework for the study of extractive graphical modeling problems. We first examine the limits of extraction by providing a characterization of the tradeoff between cyclic topology and complexity in graphical models for linear codes. Inasmuch as the cyclic topology of a graphical model is related to the performance of the decoding algorithms it implies, the bound presented in this talk provides insight into the limits of graphical model extraction. We then provide a formalization of extraction as optimization and describe some novel heuristics for both defining and solving this optimization problem. We conclude with a discussion of the importance of cyclic model extraction outside of coding.Bio: Thomas R. Halford received the B. A. Sc. degree in engineering physics from Simon Fraser University, Burnaby, B.C., Canada, in 2001. He is currently a doctoral candidate at the University of Southern California, Los Angeles, where his research focuses primarily on graphical models of codes. He spent the summer of 2005 visiting the Natural Language Processing Group at IBM T. J. Watson Research Center, Yorktown Heights, NY.Host: Prof. Keith M. Chugg, chugg@usc.edu
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Multiuser Detection in a Dynamic Environment
Wed, Sep 20, 2006 @ 10:30 AM - 11:30 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Professor Ezio Biglieri, Universitat Pompeu Fabra, Barcelona, SpainABSTRACT: In mobile multiple-access communications, not only the location of active users, but also their number varies with time. In typical analyses, multiuser detection theory assumes that the number of active users is constant and known at the receiver, and coincides with the maximum number of users entitled to access the system. This assumption is often overly pessimistic, since many users might be inactive at any given time, and detection under the assumption of a number of users larger than the real one may impair performance. This talk describes a different, more general approach to the problem of identifying active users and estimating their parameters and data in a dynamic environment where users are continuously entering and leaving the system. The goal is to lay the foundation of multiuser detection theory in an environment where the number and the parameters of active users are unknown at the receiver, and in addition may change from one observation time to the next, following a known dynamic model. Using a mathematical tool known as Random Set Theory (which will be described), I shall show Bayesian-filter equations which describe the evolution with time of the a posteriori probability density of the unknown user parameters, and use this density to derive optimum detectors. Applications of the theory to the problem of neighbor discovery in wireless networks will also be briefly discussed.BIO: EZIO BIGLIERI received his training in Electrical Engineering from Politecnico di Torino (Italy), where he received his Dr. Engr. degree in 1967. He is presently with Universitat Pompeu Fabra, Barcelona, Spain; previously, he held professorships at Universita` di Napoli, Italy, Politecnico di Torino, Italy, and UCLA.In 1996--1997 he served as chairman of the IEEE Communications Society Awards Committee. In 1988, 1992, and 1996 he was elected to the Board of Governors of the IEEE Information Theory Society. In 1999 he was the President of the Society. He was the co-chairman of the IEEE 2000 International Symposium on Information Theory, Sorrento, Italy, and of ISITA 2004, Parma, Italy. He is a Distinguished Lecturer for the IEEE Information Theory Society and the IEEE Communications Society.From 1988 to 1991 he was an Editor of the IEEE Transactions on Communications, and from 1991 to 1994 an Associate Editor of the IEEE Transactions on Information Theory. From 1997 to 1999 he was an Editor of the IEEE Communications Letters, and its Editor-in-Chief from 2003 to 2005. From 1991 to 1997 he was an Editor of the European Transactions on Telecommunications, and its Editor in Chief from 1997 to 2001. Among other honors, in 2000 he received the IEEE Third-Millennium Medal, and the "IEEE Donald G. Fink Prize Paper Award." In 2001 he received the "IEEE Communications Society E. H. Armstrong Achievement Award." In 2004 he was presented the "Journal of Communications and Networks Best Paper Award."Host: Prof. Giuseppe Caire, caire@usc.edu
Location: Hedco Neurosciences Building (HNB) - 107
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Recent developments in hydrometeorologic information for hydrologic and water resources application
Wed, Sep 20, 2006 @ 02:00 PM - 03:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:
Soroosh Sorooshian, Ph.D., N.A.EDistinguished Professor Civil & Environmental Engineering and Earth System Science, The Henry Samueli School of Engineering, University of California at IrvineAbstract:
The need for more effective management of water resources is greater than ever, particularly in arid and semi-arid regions of the world. Water resources managers must utilize more sophisticated hydrologic prediction tools. Depending on the problems, the hydrologic information needed may range from hourly forecasts (i.e., in the case of flash floods) to seasonal to inter-annual (i.e., in the case of reservoir operation), and to decadal to century (i.e., in the case of water supply structural design).
Over the past 40 years and with the advent of digital computers, hydrologic models of various levels of sophistication have been developed. Furthermore, in the past two decades hydrologists, meteorologist and ecologists have teamed up to work on critical coupled land surface and atmospheric processes. One of the challenges facing the research community has been to identify and overcome some of the key bottlenecks hindering marked improvements in hydrologic forecasting in terms of extended lead time and accuracy.
In addition to a review of the above issues, this presentation will also describe the importance of improved precipitation observations and prediction for hydrologic forecasting as well as the role of large-scale initiatives such the GEWEX program in addressing hydrometeorolgical information gaps.
Location: Kaprielian Hall (KAP) - riellian Hall, Room 203
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Title: Intelligent pen-based interfaces and their applications to CAD and education.
Wed, Sep 20, 2006 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
T. StahovichUniversity of California, Riverside
Mechanical Engineering DepartmentAbstractSketching with pencil and paper has always been an important means of
communication and problem-solving for designers and engineers. There are a
variety of reasons for this. For example, sketches are a convenient tool for
examining geometric, temporal, and other such relationships, which cannot be described easily in words. Similarly, the simplicity and ease of creating a
sketch allows one to focus on problem solving rather than the communication
medium. Yet, despite the importance of sketches in engineering practice,
traditional engineering software can do little with them. We are working to
change this by creating sketch understanding techniques that enable software
to work directly from the kinds of sketches engineers ordinarily draw. This
talk will present techniques for interpreting free-hand sketches and
transforming them into models suitable for use with engineering analysis
tools. The talk will also present examples of pen-based engineering tools we
have developed with our techniques. Finally, the talk will conclude with a
discussion of recent applications of this work to the development of
pen-based educational software.BIO
Dr. Stahovich received a B.S in Mechanical Engineering from UC Berkeley in 1988. He received an S.M. and Ph.D. from MIT in 1990 and 1995 respectively. He conducted his doctoral research at the MIT Artificial Intelligence Lab. After serving as an Assistant and Associate Professor of Mechanical Engineering at Carnegie Mellon University in Pittsburgh, PA, Dr. Stahovich joined the Mechanical Engineering Department at UC Riverside in 2003. He also currently holds cooperative appointments in the Computer Science and Electrical Engineering Departments at UC Riverside. His research interests include pen-based computing, design automation, and design rationale management.
Location: Stauffer Science Lecture Hall, Rm 100
Audiences: Everyone Is Invited
Contact: April Mundy
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The Physical View of Computational Complexity
Fri, Sep 22, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Dr. Allon Percus
Division of Computer, Computational and Statistical Sciences, LANL / Department of Mathematics, UCLAPhysicists define a phase transition as an abrupt change in microscopic order, such as the transition from a solid to a liquid. Many fundamental problems in computer science exhibit phase transitions as well. The classic example is satisfiability: given a set of logical constraints acting on Boolean variables, can one assign truth values to the variables so that all constraints are simultaneously satisfied? For randomly generated formulas with many variables, as one increases the number of constraints per variable, there is a threshold at which the answer goes abruptly from almost certainly yes to almost certainly no. Moreover, this phase transition is connected with algorithmic performance. Over a wide range of computational problems, the hardest instances to solve are those near the transition. I will discuss the role of phase transitions in random combinatorial problems,demonstrating how the physical view of the phase structure has transformed our understanding of average-case computational complexity and inspired new algorithmic approaches.Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Shane Goodoff
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Finite-Length Optimization of Iterative Coding Systems Via Scaling
Fri, Sep 22, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Prof. Ruediger Urbanke, Swiss Federal Institute of TechnologyABSTRACT: The infinite-length performance of iterative coding systems is by now relatively well understood. Much less is known about the practical important case of finite-length codes. I will argue that a method called "finite-length scaling", which is based on relating the code performance of various lengths, is a useful tool for the analysis and optimization of real systems. This method has the advantage that it is in principle applicable in a fairly general setting.So far, however, the method has been worked out explicitly only for the case of transmission over the binary erasure channel and we are just about to understand the case of transmission over the binary symmetric channel under Gallager A decoding.I will describe what remains to be done and what we can expect to see as final result.[This is joint work with Abdelaziz Amraoui, Jeremie Ezri, and Andrea Montanari.]Bio: Ruediger L. Urbanke received his Diplomingenieur from the Vienna Institute of Technology in 1990 and his M.S. and Ph.D. in Electrical Engineering from Washington University in 1992 and 1995, respectively. From 1995-1999 he held a position at the Mathematics of Communications Department at Bell Labs. Since November 1999, he has been on the Faculty of the Swiss Federal Institute of Technology in Lausanne. He is a recipient of a Fulbright Scholarship and a co-recipient of the IEEE Transactions on Information Theory 2002 Best Paper Award. Since October 2000 he has been an Associate Editor of the IEEE Transactions on Information Theory.Host: Prof. Giuseppe Caire, caire@usc.edu
Location: Vivian Hall of Engineering (VHE) - 217
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Chem-Bio Informatics Approaches to Drug Design by Dr. Rajni Garg
Fri, Sep 22, 2006 @ 01:00 PM - 02:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Computer assisted drug design techniques play a major role in lead optimization in drug discovery and development, which significantly reduces the time and cost. Chem.-bio informatics encompasses the design, organization, storage, management, retrieval, analysis, dissemination, visualization and use of chemical and biological information. Various tasks involved are data mining, molecular modeling (docking), defining quantitative structure-activity relationships (QSAR), pharmacophore mapping, structure/substructure searching etc. for predicting biological activity and other properties from chemical structure. Lately, many engineering approaches such as data mining, neural networks, pattern recognition, shape analysis and 3D graphics are being increasingly applied for multi-modality data analysis in order to understand the drug-receptor interaction. In the first part of the talk an introduction of QSAR, neural network, pharmacophore mapping and some of the molecular modeling techniques will be presented. The second half will focus on role of some of the emerging approaches in chem.-bio informatics and a few selected applications in HIV drug design and environmental toxicity will be presented.Bio:
Dr. Rajni Garg received the Ph.D. degree from Birla Institute of Technology and Science (BITS), Pilani, India in 1996. She joined Professor Corwin Hansch’s laboratory for her postdoctoral research in 1997. She is now a Research Professor in Chemistry and Bimolecular Science Department at Clarkson University, NY; and chemistry and Biochemistry Department at Cal State, San Marcos, CA. Her research interests are in the areas of computer-aided drug design, database development, data mining, chembioinformatics, and environmental toxicity prediction. Dr. Garg is a member of ACS, ISCB, AAAS and many other Societies. She received ACS Cycle of Excellence Award for most accessed article in Chem. Rev. in 2004. Currently, Dr. Garg is advising 3 graduate students research at Clarkson University (see website www.clarkson.edu/~rgarg). Students in her lab have received prestigious CCG Excellence Graduate Award (230th ACS National Meeting, 2005), Shipley Teaching Assistantship award (2005-2006), and CINF- Graduate Fellowship (231st ACS National Meeting, 2006) and summer internships in Pfizer, Wyeth etc. Dr. Garg is a co-author of 32 technical publications in international journals. She has presented her research in 37 national and international conferences as well as contributed two book chapters. Dr. Garg serves as expert reviewer for articles submitted in Mini-Reviews in Medicinal Chemistry, Current Medicinal Chemistry, Bioorganic Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters, Internet Electronic Journal of Molecular Design and Letters in Drug Design and Discovery.Host: Professor CC Jay Kuo, x04658, cckuo@sipi.usc.eduLocation: Grace Ford Salvatori Hall Of Letters, Arts & Sciences (GFS) - 116
Audiences: Everyone Is Invited
Contact: Gloria Halfacre
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Evaluating Extremely Impaired Drinking Water Sources
Fri, Sep 22, 2006 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Stefan Cajina, P.E.
District Engineer, Central District
California Department of Health Services
Drinking Water ProgramAbstractThe primary goal of the California Department of Health Services, Drinking Water Program (CDHS) is to ensure that all Californians receive a reliable supply of safe drinking water. To this end, CDHS seeks to approve the use of only high-quality sources of drinking water. As populations increase, however, and domestic demands on the state's water resources grow, more water utilities are proposing to treat and distribute water from "extremely impaired" sources to their customers. CDHS may consider a drinking water source to be extremely impaired for various reasons, including high levels of contamination, a mixture of contaminants of health concern, proximity to known contaminating activities, or use of the source to intercept contaminants of health concern.The use of extremely impaired sources of drinking water may increase the health risk to the public, and should therefore be avoided when high-quality sources are available. In the past, some treatment projects involving extremely impaired sources have proved inadequate due to increasing contaminant levels or the appearance of unexpected contaminants. However, CDHS recognizes that many local water supplies need to be cleaned up, and that the resulting product water represents a significant resource that should not be wasted. In some situations, particularly when high-quality sources are overtaxed or unavailable, CDHS may consider the use of extremely impaired sources for domestic water supply. In such cases, the source water must be thoroughly and reliably treated to remove all contaminants of health concern. In order to approve such a project, CDHS must thoroughly evaluate the proposal and conclude that public health is adequately protected. In addition, the project must be acceptable to consumers. CDHS developed Policy Memorandum 97-005 – Policy Guidance for Direct Domestic Use of Extremely Impaired Sources, to guide staff in the evaluation of such proposals.The evaluation process as set forth in Policy 97-005 consists of 12 essential elements:
1. Source water assessment
2. Full characterization of the raw water quality
3. Evaluation of source protection program
4. Evaluation of monitoring and treatment
5. Evaluation of human health risks associated with failure of proposed treatment
6. Identification of alternatives to the use of the extremely impaired source and comparison of potential health risks
7. Completion of the California Environmental Quality Act (CEQA) review of the project
8. Submittal of a permit application
9. Public hearing
10. CDHS evaluation
11. Finding that project meets or does not meet CDHS requirements for approval
12.Issuance or denial of permitBy completing the Policy 97-005 evaluation process, water utilities, CDHS, and the public can make informed decisions regarding the use of extremely impaired sources. Any treatment project that is approved by CDHS for domestic water supply may be expected to protect public health for the life of the project.
Location: Kaprielian Hall (KAP) - rielian Hall 156
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Honors Program Colloquium: The Demographic Time Bomb
Fri, Sep 22, 2006 @ 01:00 PM - 02:00 PM
Viterbi School of Engineering Student Affairs
Conferences, Lectures, & Seminars
Engineering Honors Colloquium lecture given by Dr. James Doane, Manager of Knowledge Management Services at Jet Propulsion Labratory
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Faculty and Honors Program Students
Contact: Erika Chua
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Material Science Seminar
Fri, Sep 22, 2006 @ 02:30 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Ng Lam (Argonne National Lab)
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce
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The Situation of Chinese Manufacturing and Theory of Modern Design
Wed, Sep 27, 2006 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Y.B. Xie Professor Shanghai Jiaotong University
and Xi'an Jiaotong University
Shanghai, People's Republic of China The problem with Chinese manufacturing is that how China can become a strong manufacturing country from a big manufacturing country? The situation is: 1. Lack of new Knowledge with Chinese own property. 2. Lack of the capability of discovering and describing new Knowledge with Chinese own property. 3. Lack of the Knowledge of inserting new technologies in new design, say capability of matching, of making optimum life cycle performance and of meeting the life cycle constrain requirements. Our strategy and the activities for solving the problem are developing a distributed resource environment in China, any enterprise anywhere can ask and obtain Knowledge Service for design activities providing by intelligent resource units outside of the enterprise via internet or other tools in such an environment. Some theoretical results coming from the activities form what we called the Theory of Modern design.
Location: Stauffer Science Lecture Hall, Room 100 (SLH 100)
Audiences: Everyone Is Invited
Contact: April Mundy
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Analysis of Delay, Capacity, and Capacity Deficit in Multihop
Thu, Sep 28, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Dr.Nabhendra Bisnik - Rensselaer Polytechnic InstituteMultihop wireless networks, such as wireless ad hoc, sensor, and mesh networks, have applications in a variety of fields like providing connectivity to communities, surveillance, monitoring, defense, etc. However scalability of such networks is marred by scarce bandwidth, broadcast nature of the wireless medium, and dynamic nature of network topology due to node mobility. In this talk we present analytical techniques for characterizing delay, capacity, and the capacity deficit caused by routing protocol overheads. We present a queuing theory approach to evaluate average end-to-end delay and maximum achievable per-node throughput in random access MAC based wireless ad hoc and mesh networks. The model takes into account the number of nodes, the random packet arrival process, the extent of locality of traffic, and the backoff and collision avoidance mechanisms of random access MAC. We model the random access multihop wireless networks as open G/G/1 queuing networks and use the diffusion approximation method for evaluating closed form expressions for average end to end delay. In order to characterize the impact of routing overheads on the actual capacity available to network users for transmitting data we present an information theoretic framework for analyzing the minimum routing overheadincurred by geographic routing in mobile ad hoc networks. We formulate the minimum routing overhead problem as a rate distortion problem and evaluate a lower bound on the minimum routing overhead incurred for routing packets with desired level of reliability. We characterize the effective transport capacity of ad hoc networks available to the users for transmitting data, after taking into account the minimum overheads that must be incurred for reliable routing. We also present results on the critical network size, above which the entire transport capacity of the network may be consumed by the routing overheads
Location: Frank R. Seaver Science Center (SSC) - 319
Audiences: Everyone Is Invited
Contact: Shane Goodoff
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Chemical Engineering and Materials Science Seminar
Thu, Sep 28, 2006 @ 02:30 PM - 04:00 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Ultrafast Biological Dynamics at Atomic Scale Dongping ZhongDepartments of Physics, Chemistry and Biochemistry,
Programs of Biophysics, Chemical Physics and Biochemistry,
The Ohio State University, 191 West Woodruff Avenue, Columbus, OH 43210, USAProtein dynamics is a complex process and the current challenge is to break down its complexity into elementary processes which act on different time scales and length scales. We integrate femtosecond spectroscopy, molecular biology techniques, and computational simulations to study functional evolution in real time and thus elucidate the complex dynamics with unprecedented detail. Here, two important biological systems, protein surface hydration and light-driven DNA repair, will be reported. With femtosecond temporal and single-residue spatial resolution, we mapped out the global water motion in the hydration layer using intrinsic tryptophan residue to scan the protein surface with site-directed mutagenesis. The results reveal the ultrafast nature of surface hydration dynamics and provide a molecular basis for protein conformational flexibility, an essential determinant of protein function. For DNA repair, we followed the entire functional evolution through femtosecond synchronization. We resolved a series of ultrafast processes including active-site solvation, energy transfer, and electron tunneling. These results elucidate the crucial role of ultrafast dynamics in control of biological function efficiency and lay bare the molecular mechanism of DNA repair at atomic scale.
Location: John Stauffer Science Lecture Hall (SLH) - 102
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Natural Gas Geochemistry in the Tarim Basin, China and Its Indication to Gas Filling History
Fri, Sep 29, 2006 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Dr. Tongwei Zhang
Power, Environmental, and Energy Research Center
California Institute of TechnologyAbstract:
Natural gases in the Tarim basin, China are primarily composed of methane, whose content is more than 70%, with variable contents of ethane (Location: Kaprielian Hall (KAP) - 156
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Honors Program Colloquium: Work of the Getty Conservation Institute in LA and in 30 Countries Abroad
Fri, Sep 29, 2006 @ 01:00 PM - 02:00 PM
Viterbi School of Engineering Student Affairs
Conferences, Lectures, & Seminars
Engineering Honors Colloquium lecture given by Mr. Francois LeBlanc, Head of Field Projects at the Getty Conservation Institute.
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Faculty and Honors Program Students
Contact: Erika Chua
