ECE 6900/7900 Graduate Seminar
Fall Semester 2013
Instructor: Prof. Gianluca Lazzi, email@example.com
Location: WEB 1250
Meeting Time: Mondays at 3:05-3:55 p.m.
Teaching Assistant: Nazmul Hasan, firstname.lastname@example.org
General Course Information and Requirements
- This is a credit/no credit class required of all MS/ME students. A student continuing for the Ph.D. degree must register for ECE 7900/7910 after having previously taken ECE 6900 and 6910 during their MS/ME program.
- A tentative Graduate Seminar Schedule for the beginning of Fall 2013 is indicated below. Several of the seminars have yet to be announced. These slots will be filled in due course, and the speakers and topics of the seminars will be announced as the information becomes available.
- To receive credit for this class, a student must attend at least 70% of the seminars offered. Based on the current estimate of seminars that will be offered this semester (15), this translates into attending at least 11 seminars.
- Seminar attendance will be recorded through the students UCard. Each student registered for the course will be registered in the system using the serial number from their UCard. It is a student’s responsibility to bring their UCard to each seminar, scan it with the UCard reader that the course’s TA brings to class, and stay for the duration of the seminar to get credit.
- The first graduate seminar of Fall Semester will be held on Monday, August 26th, 2013.
- Students are expected to turn in a well-written report on any seminars that they attended during the year. Students may compensate for 2 absences by turning in an additional report on the research of any single graduate seminar speaker. Reports should be turned in to the course instructor before the last day of the semester.
December 29th, 2013
Dr. James C. M. Hwang Lehigh University When: Monday, January 6, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract Using a novel broadband microchamber, electrical detection of live and dead single cells was demonstrated. Tests on Jurkat cells showed that live cells had lower resistance but higher capacitance than that of dead cells. The test results were compared with the limited literature on broadband electrical detection of single cells and the discrepancies, both qualitative and quantitative, were discussed. These results indicate that, while broadband electrical detection at the single-cell level is becoming feasible, many challenges remain in impedance match, calibration, sensitivity, cell manipulation, solution effect and modeling. Speaker Biography Dr. James Hwang is Professor of Electrical Engineering and Director of Compound- Semiconductor Technology Laboratory at Lehigh University. He graduated with a B.S. degree in Physics from National Taiwan University in 1970, and completed M.S. (1973) and Ph.D. (1976) studies in Materials Science at Cornell University. After twelve years of industrial experience at IBM, AT&T, GE, and GAIN, he joined Lehigh in 1988. He cofounded GAIN and QED; the latter became a public company (IQE). He has been a Nanyang Professor at Nanyang Technological University in Singapore, as well as an advisory professor at Shanghai Jiao Tong University, East China Normal University, and University of Science and Technology in China. Most recently, he was a Program Officer for GHz-THz Electronics at the Air Force Office of Scientific Research. He is a fellow of the Institute of Electrical and Electronic Engineers. He has published ~300 refereed technical papers and has been granted five U. S. patents.
January 7th, 2014
Dr. Jeffrey Walling University of Utah ECE Dept. When: Monday, January 13, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract CMOS is used nearly ubiquitously for digital computation, and as such plays an ever increasing role in our lives as we increasingly use computation to improve working efficiency. Increasing levels of integration have made it possible to embed analog and RF circuits with digital processing on a single integrated circuit. The RF power amplifier (PA) has been the exception to integration in CMOS, owing to its relatively poor performance (e.g., peak output power and energy efficiency) when compared to other semiconductor technologies (e.g., III-V compounds and SiGe). In this talk I will digital PAs (DPAs), which leverages CMOS inherent strengths of fast switching speeds and superior lithographic matching to yield a linear, efficient digital power amplifier. I will also examine current research in the University of Utah Power Efficient RFIC lab addressing limitations in DPAs, and High power PAs using GaN devices. The aim of such PAs is to enable reconfigurable operation for software-defined and cognitive radios. Speaker Biography Dr. Walling received the B.S. degree from the University of South Florida, Tampa, in 2000, and the M.S. and Ph. D. degrees from the University of Washington, Seattle, in 2005 and 2008, respectively. Prior to starting his graduate education he was employed at Motorola, Plantation, FL working in cellular handset development. He interned for Intel, Hillsboro from 2006-2007, where he worked on highly-digital transmitter architectures and CMOS power amplifiers and continued this research while a Postdoctoral Research Associate with the University of Washington. He is currently an assistant professor in the ECE department at University of Utah. His current research interests include low-power wireless circuits, energy scavenging, high-efficiency transmitter architectures and CMOS power amplifier design for software defined radio. Dr. Walling has authored over 30 articles in peer reviewed journals and refereed conferences. Recently he received the Best Paper Award at Mobicom 2012. He has also received the Yang Award for outstanding graduate research from the University of Washington, Department of Electrical Engineering in 2008, an Intel Predoctoral Fellowship in 2007-2008, and the Analog Devices Outstanding Student Designer Award in 2006.
January 21st, 2014
Larry Anderton - Chief Engineer, and Jon Lea - Advanced Technology and Research Manager GE Healthcare When: Monday, January 27, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract Minimally invasive surgery (MIS) is a surgical paradigm to improve patient care through smaller incisions. The result is lowered costs and improved quality due to shortened hospital stays, reduced infection rates, and treatment for conditions that were previously not possible. A key technology in MIS is the mobile x-ray fluoroscope (aka “C”-arm). By providing live high resolution x-ray images of the patient during surgery, a surgeon can track the tip of a guide wire in a vessel or watch the trajectory of a screw being placed in the hip joint. The development of mobile fluoroscopy presents several interesting design challenges. Power is not always available at the requisite level (up to 15 kW) from a standard wall socket. X-ray tubes are notoriously inefficient, shedding more than 99% of the input energy as waste heat. Further, a very small fraction of the incident x-rays reach the image detector, generally less than 1 percent and depends on patient thickness. Resultant images are inherently noisy due to low photon counts that reach the image detector. We will cover current solutions to these problems and introduce concepts where developing technologies can further improve the imaging performance of x-ray fluoroscopy and provide better safety to patient and surgical staff. About the Presenters Larry Anderton is the Chief Engineer for the Surgical Division of GE Healthcare. His career began at Unisys as a test technician, progressed to Edo Western Corporation where he held several positions from field service through engineering. His product design experience included sonar depth sounding, side-scan sonar, and high resolution video camera design for underwater and aerospace applications. In 1978, Larry joined the Varian Ultrasound division of Varian Associates, where he became involved in analog circuit design for phased array ultrasound products, C-arm fluoroscope video systems design, and later, x-ray generator design. In 1995, he accepted the position of Chief Engineer. Larry currently holds 13 patents relating to x-ray fluoroscopy. Larry has enjoyed a lifelong hobby in electronics and amateur radio. Jon Lea is the Advanced Technology and Research Manager for the Surgical Division of GE Healthcare. Jon received his undergraduate and graduate degrees from Western Michigan University and Northwestern University respectively, with a focus on robotics for surgery. Jon was co-founder of Surgical Insights, a developer of surgical navigation applications for orthopedics, which was acquired by GE in 2001. He held several technical positions within GE's surgical navigation business in the Boston area before relocating to Utah. He enjoys downhill skiing , mountain biking, and playing guitar and piano.
January 23rd, 2014
Dr. Alexis Kwasinski University of Texas-Austin When: Monday, February 3, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract This presentation analyzes system-level planning and component-level design approaches to achieve high power supply availability during and after natural disasters. It starts by explaining the motivation of this analysis with a description of photographic evidence and information collected during field damage assessments after recent notable natural disasters. This evidence seems to indicate that conventional power grids are very fragile systems due to their primarily centralized power distribution and control architectures and explains why conventional mitigation strategies and many smart grid technologies yield limited resiliency improvement. The second part of this presentation introduces microgrids as an alternative technology that does not have these limitations. A system-level analysis indicates that resilient microgrids need to include diverse power sources and/or local energy storage. Then, the presentation moves on to explore suitable power electronic interfaces to integrate diverse power sources, and advanced power distribution architectures to improve resiliency to natural disasters. The effects that these power distribution architectures have on stability and control are also discussed. The presentation concludes with a description of uses of resilient microgrids in key applications, such as wireless communication networks, and an exploration of future research paths. Speaker Biography Alexis Kwasinski earned his M.S. and Ph.D. degrees in electrical engineering from the University of Illinois at Urbana-Champaign (UIUC) in 2005 and 2007, respectively. Previously, he spent almost 10 years working for Telefónica of Argentina and for Lucent Technologies Power Systems. He is currently an Associate Professor in the Department of Electrical and Computer Engineering at The University of Texas at Austin and his research interests include power electronic systems, distributed generation (microgrids), renewable and alternative energy, smart grids, and analysis of the impact of natural disasters on critical power infrastructure. He participated in damage assessments after natural disasters, including hurricane Katrina and the March 2011 earthquake and tsunami in Japan. In 2005, Dr. Kwasinski was awarded the Joseph J. Suozzi INTELEC Fellowship and in 2007 he received the best technical paper award at INTELEC. In 2009 he received an NSF CAREER award and in 2011 he received an IBM Faculty Innovation Award. Dr. Kwasinski is also an Associate Editor for the IEEE Transactions on Energy Conversion and IEEE Transactions on Power Electronics.
January 24th, 2014
Mr. Joel B. Harley, PhD Candidate Carnegie Mellon University When: Monday, February 10, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract In engineering and the sciences, there is considerable interest in technology to sense and monitor large-scale, physical environments. These systems have diverse applications in many fields, including civil and aerospace engineering, medicine, oceanography, and seismology. For civil and aerospace applications, these technologies can be used to noninvasively monitor the structural integrity of bridges, pipes, airplanes, and other modern structures. This can reduce maintenance costs and prevent catastrophic failures in our current transportation, power, and resource distribution networks. Ultrasonic guided waves (waves that are “guided” by the geometry of the environment) have been of particular interest for monitoring critical infrastructures due to their sensitivity to damage and capability to interrogate large areas at once. To detect, locate, and evaluate damage, ultrasonic guided waves are measured and analyzed using various signal processing strategies. However, successfully detecting and locating damage is challenging because the complex propagation environments significantly distort the waves as they travel through the medium. This talk presents a signal processing framework for overcoming these challenges by combining physical models of ultrasonic waves with novel computational methods and data-driven strategies to learn the complex characteristics of guided waves. We demonstrate how these characteristics can be learned from experimental data and how to leverage this information to improve the detection and localization of damage in critical infrastructures. We also briefly discuss how these strategies can be extended other applications. Speaker Biography Joel B. Harley received the B.S. degree in electrical engineering from Tufts University, Medford, MA, in 2008 and a M.S. degree in electrical and computer engineering from Carnegie Mellon University, Pittsburgh, PA in 2011. He is currently working toward a Ph.D. degree in electrical and computer engineering at Carnegie Mellon University, Pittsburgh, PA. His interests include the integration of complex wave propagation models with novel signal processing, machine learning, and big data methods for applications in cyber-physical systems, structural health monitoring, nondestructive evaluation, and other fields. Mr. Harley is a recipient of the 2009 National Defense Science and Engineering Graduate (NDSEG) Fellowship, the 2009 National Science Foundation (NSF) Graduate Research Fellowship, the 2009 Department of Homeland Security Graduate Fellowship (declined), and the 2008 Lamme/Westinghouse Electrical and Computer Engineering Graduate Fellowship. He has published more than 30 technical journal and conference papers, including four best student papers. He is a student representative for the IEEE Ultrasonics, Ferroelectrics, and Frequency Control Society, a member of the IEEE Signal Processing Society, and a member of the Acoustical Society of America.
"Using Differential Power Processing Converters in Photovoltaic Systems to Improve Lifetime Energy Production"
January 27th, 2014
Ms. Katherine Kim, PhD Candidate University of Illinois at Urbana-Champaign When: Friday, February 14, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract Photovoltaic (PV) energy systems are gaining popularity in both residential and commercial markets. Traditionally, PV panels are connected in series to a central inverter that maximizes power production and delivers energy to the power grid. When PV cells are connected in series, they often experience mismatch that reduces the total output power. PV mismatch can be caused by various factors, such as non-uniform lighting, partial shading, inconsistent manufacturing, local temperature gradients, and degradation from aging and environmental stress. Dc optimizers are panel-level dc-dc converters that can be used to mitigate this mismatch by independently optimizing each panel’s power. However, dc optimizers must be rated at the full panel power and process all of the power from the PV panel. Differential power processing (DPP) is an alternative solution that achieves high system efficiency by processing a fraction of the total power, while still optimizing power output from each PV panel. DPP converters can also be rated at a lower power level than dc optimizers, which offers potential cost reduction, reliability enhancement, and higher efficiency. This presentation details the operation of two DPP architectures: PV-to-bus and PV-to-PV. Simulations for both DPP architectures are used to evaluate system performance over 25 years of operation. The level of mismatch among PV panels at 25 years is estimated based on data from long-term field studies. Converter ratings of 15-17% for PV-to-bus and 23-33% for PV-to-PV architectures are identified as appropriate ratings for a 15-submodule PV system. Using Monte Carlo simulation, lifetime performance of the PV-to-bus and PV-to-PV architectures is compared to conventional architectures. DPP converters are shown to deliver 6% more energy compared to the conventional series string architecture at 25 years of operation. This presentation will also speak to future applications of DPP converters in mobile PV applications, such as vehicles and wearable electronics. Speaker Biography Katherine Kim graduated with a B.S. in Electrical and Computer Engineering from Franklin W. Olin College of Engineering in 2007. She received her M.S. in Electrical and Computer Engineering at the University of Illinois at Urbana-Champaign in 2011, and plans to complete her Ph.D. degree in 2014 under Prof. Philip Krein. Katherine’s dissertation research is in power electronics, modeling, control, and protection for photovoltaic systems. She received the National Science Foundation’s East Asia and Pacific Summer Institutes Fellowship in 2010 and Graduate Research Fellowship in 2011. She is currently the Student Membership Chair for the IEEE Power Electronics Society and is active in the student chapter at the University of Illinois.
February 11th, 2014
Guest Speaker When: Friday, February 21, 2014 at 3:05 p.m.Where: Warnock 1230
February 13th, 2014
Guest Speaker When: Monday, February 24, 2014 at 3:05 p.m.Where: Warnock 1230
February 13th, 2014
Dr. Harpreet Dhillon, Postdoctoral Research Associate University of Southern California - Los Angeles When: Friday, February 28, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract The increasing complexity of heterogeneous cellular networks (HetNets) due to the irregular deployment of small cells demands significant rethinking in the way cellular networks are perceived, modeled and analyzed. In addition to threatening the relevance of classical models, this new network paradigm also questions the feasibility of state-of-the-art simulation-based approach for system design. In this talk, I will discuss an alternate approach based on random spatial models that is not only tractable but also captures current deployment trends fairly accurately. First, I will present a general baseline model consisting of K different types of base stations (BSs) that may differ in terms of transmit power, deployment density and target rate. Modeling the locations of each class of BSs as an independent Poisson Point Process (PPP) allows the derivation of surprisingly simple expressions for key performance metrics. One interpretation of these results is that adding more BSs or tiers does not necessarily change the coverage probability, which indicates that the fears of "interference overload" in HetNets are probably overblown. Second, I will discuss how the baseline model can be generalized to study self-powered HetNets, where each BS is powered solely by a self-contained energy harvesting module that may differ across tiers in terms of the energy harvesting rate and energy storage capacity. Since a BS may not always have sufficient energy, it may not always be available to serve users. This leads to a notion of “availability region”, which characterizes the fraction of time each type of BS can be made available under a variety of operational strategies. The availability region also provides a way to quantify performance degradation due to the unreliability associated with energy harvesting. Time permitting, I will also discuss a few more topics of current interest, most notably: (i) multi-antenna HetNets, and (ii) ongoing work on wireless backhaul networks. Speaker Biography Harpreet S. Dhillon received the B.Tech. in Electronics and Communication Engineering from Indian Institute of Technology (IIT) Guwahati, India, in 2008, the M.S. in Electrical Engineering from Virginia Tech, Blacksburg, VA, in 2010, and the Ph.D. in Electrical Engineering from the University of Texas (UT) at Austin, TX, in 2013. Since Fall 2013, he is a postdoctoral research associate in the Communication Sciences Institute (CSI), Department of Electrical Engineering, University of Southern California (USC), Los Angeles, CA. He has held summer internships at Alcatel-Lucent Bell Labs in Crawford Hill, NJ, Samsung Research America in Dallas, TX, Qualcomm Inc. in San Diego, CA, and Cercom, Politecnico di Torino in Italy. Dr. Dhillon is a recipient of the IEEE International Conference in Communications (ICC) 2013 best paper award in Wireless Communications Symposium, UT Austin's Wireless Networking and Communications Group (WNCG) leadership award 2013, UT Austin's Microelectronics and Computer Development (MCD) fellowship, and the Agilent Engineering and Technology Award 2008, a national award for the best undergraduate research thesis in India. His research interests are broadly in communication theory, stochastic geometry, and wireless ad ho
February 14th, 2014
Dr. Gonzalo Mateos, Visiting Scholar Carnegie Mellon University When: Monday, March 3, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract The information explosion propelled by the advent of personal computers, the Internet, and the global-scale communications has rendered statistical learning from “Big Data" increasingly important for analysis and processing. Along with data adhering to postulated models, present in large volumes of data are also those that do not -- and are referred to as outliers. In this talk, I will start with an approach to outlier-resilient principal component analysis, which establishes a neatlink between the seemingly unrelated notions of sparsity and robustness to outliers, even when the signals involved are not sparse. I will argue that controlling sparsity of model residuals leads to statistical learning algorithms that are computationally affordable and universally robust. The impact of these ideas will be demonstrated in applications as diverse as identification of aberrant responses in personality assessment surveys, and unveiling communities in social networks, as well as intruders from video surveillance data. In the second part of the talk, I will switch focus towards the important task of unveiling and mapping-out network traffic anomalies given link-level traffic measurements. Leveraging the low intrinsic-dimensionality of end-to-end network flows and the sparse nature of anomalies, I will construct an estimated map of anomalies in real time to aid in monitoring the network health state. If time allows, I will finally highlight anew additional domains that include predicting network-wide path latencies, and load curve cleansing and imputation -- a critical task in green grid analytics and energy management with renewables. Speaker Biography Gonzalo Mateos was born in Montevideo, Uruguay, in 1982. He received his B.Sc. degree in Electrical Engineering from Universidad de la Republica, Uruguay, in 2005, and the M.Sc. and Ph.D. degrees in Electrical Engineering from the University of Minnesota (UofM), Twin Cities, in 2009 and 2011.From 2004 to 2006, he worked as a Systems Engineer at Asea Brown Boveri (ABB), Uruguay. Currently, he is a visiting scholar with the Computer Science Department at Carnegie Mellon University. He also holds an appointment as a post-doctoral research associate with the Department of Electrical and Computer Engineering (ECE) and the Digital Technology Center, UofM. His research interests lie in the areas of statistical learning from Big Data, network science, wireless communications, and signal processing. His current research focuses on algorithms, analysis, and application of statistical signal processing tools to dynamic network health monitoring, social, power grid, and Big Data analytics. Since 2012, he serves on the Editorial Board of the EURASIP Journal on Advances in Signal Processing. He received the Best Student Paper Award at the 13th IEEE Workshop on Signal Processing Advances in Wireless Communications, 2012 held at Cesme, Turkey, and was also a finalist of the Student Paper Contest at the 14th IEEE DSP Workshop, 2011 held at Sedona, Arizona, USA. His doctoral work has been recognized with the 2013 UofM's Best Dissertation Award (Honorable Mention) across all Physical Sciences and Engineering areas.
February 18th, 2014
Dr. Masoud Honarvar Nazari, Post Doctoral Fellow Georgia Institute of Technology When: Friday, March 7, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract In this talk, I will first discuss needs for transforming today’s fossil-fuel dependent and highly polluting electric power systems into sustainable, efficient, and reliable electric energy systems, which have functionalities similar to Internet. Next, I will present my recent efforts to design a distributed decision-making and control architecture for internet-like energy systems. I will discuss the fundamental differences between internet-like distribution energy systems and conventional transmission power systems, regarding dynamic behavior under a high penetration of distributed generators. Then, I will present a novel distributed frequency regulation architecture, whereby frequency regulators communicate with their neighbors in the network in order to improve performance. I will show that despite the frequency regulators being distributed, stability can be ensured while avoiding inter-area oscillations using a limited control effort. The efficacy of the proposed frequency regulation framework is shown through simulations on two real-world electric energy systems of different scale and complexity. Speaker Biography Masoud Honarvar Nazari is a Post Doctoral Fellow in the School of Electrical and Computer Engineering at Georgia Institute of Technology. He received his first Ph.D. in Electrical and Computer Engineering in a joint program between Carnegie Mellon University and the University of Porto, Portugal in 2012 and obtained his second Ph.D. in Engineering and Public Policy from Carnegie Mellon in the same year. He was a visiting scholar at MIT Energy Initiative in 2010. He was also awarded the five-year international FCT (Fundação para a Ciência e a Tecnologia) fellowship in 2007. His research interests include Power System and Smart Grid operation; Distributed Control Architecture for Internet-like Energy Systems; Large-scale Integration of Distributed Energy Sources, and; Policy implication and regulation design for modernizing Electric Power Systems. He has several book chapters, journals, and conference papers in the subject of Power System Stability and Control.
March 13th, 2014
Mr. Tom Armstrong, Chief Technologist for Broadband Communication Systems Applied Signal Technology - Raytheon Space and Airborne Systems When: Monday, March 17, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract The Global Telecommunication Network touches our lives daily, and many do not appreciate the complexity of the network. This talk introduces fundamental engineering concepts of the network in a simplified view, and shows that the evolution of the core network in meeting today’s communication needs has not changed since the late 1800s. Speaker Biography Tom Armstrong is the chief technologist for Broadband Communication Systems in the Applied Signal Technology mission area of Raytheon Space and Airborne Systems. In this role, he provides direction and vision in all technical aspects of signal communications and intelligence product and system development and deployment: aspects including product design, system integration and test, operations and maintenance, and mission management and analysis. He is also a Raytheon Applied Signal Technology Senior Fellow and in such capacity he directs research and development in advanced modulation, high speed switching, error correction, signal multiplexing, communication protocols, and signal processing technologies. Prior to joining Raytheon Applied Signal Technology in 1999, Armstrong enjoyed a twelve-year career at the U.S. Department of Defense. He served in many technical capacities. In his final position with the DoD, he served as Technical Director of one of the operational divisions where he oversaw all aspects of design, development, and deployment of multiple signal communications systems. Mr. Armstrong earned his bachelor and master degrees in electrical engineering from the University of Utah in 1986 and 1987, respectively. On two different occasions—in 1997 and again in 2004—he received a Meritorious Citation from the US Government for exceptional achievement and superior performance which contributed significantly to the deployment of a major technical system of national importance.
March 25th, 2014
Dr. Willie Padilla, Professor Dept. of Physics, Boston College When: Friday, April 4, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract Metamaterials are artificial electromagnetic materials which have realized exotic electromagnetic responses including negative index of refraction and invisibility cloaking. As the underlying physics of these fascinating materials continues to be uncovered, effort is now shifting toward demonstration of devices. I will present the design, fabrication, and demonstration of active metamaterials that function as a real-time tunable, spectrally sensitive spatial masks for use in THz imaging with only a single pixel detector. Speaker Biography Willie Padilla received a PhD from the UC San Diego and was a Director’s Postdoctoral Fellowship at Los Alamos National Laboratory. In 2006 he joined the Department of Physics at Boston College and is a Full Professor. In 2007 he was awarded a Young Investigator Award from the Office of Naval Research and Presidential Early Career Award for Scientists and Engineers in 2011. In 2012 he was elected a Fellow of the Optical Society of America and a Kavli Frontiers of Science Fellow in 2013.
March 31st, 2014
Bryan R. Loyola, Steven Paradise, Christopher Hall Sandia National Laboratories When: Monday, April 7, 2014 at 3:05 p.m.Where: Warnock 1230 Abstract The United States is facing a two-pronged infrastructure problem. Many new structures are being built with state-of-the-art materials that do not perform like traditional engineered materials, while the remainder of America’s civil infrastructure is deteriorating at an alarming rate. A recent American Society of Civil Engineers’ report has rated the civil infrastructure of the United States at an overall D+ rating. In addition, fiber-reinforced composite materials are being introduced into many structures, particularly in aircraft, at a higher rate. Unlike traditional monolithic metals, composites manifest their damage internal to their structure, making the damage barely detectable to visual inspection. Researchers across the world have focused their attention towards creating new sensors, sensing methodologies, and sensor platforms to be able to instrument these structures to detect the onset of damage due to environmental conditions and events. In this talk, a sensing skin approach will be discussed aimed at detecting damage in fiber-reinforced polymer (FRP) materials, like those used in aircraft or wind turbines. A carbon nanotube-based latex paint has been developed and demonstrated to be sensitive to applied mechanical strain, changes in temperature, and cracking via changes in the film’s electrical conductivity. These sensitivities are utilized by an approach called electrical impedance tomography (EIT), which measures the spatially distributed conductivity across the CNT-based paint. Changes in localized electrical conductivity are indicative of strain, changes in temperature, or impact damage in the specified location. This approach allows for the detection, localization, size evaluation, and severity of damage within the sensing region. This talk will explain how EIT has been applied to detecting damage with applied and embedded CNT films in glass fiber-reinforced polymer composites, as well as using the inherent electrical conductivity of carbon fiber-reinforced polymer composites. Speaker Biographies Dr. Bryan Loyola is a Senior Member of Technical Staff at Sandia National Laboratories in Livermore, California. He earned a B.S. in Physics from the University of California, Davis in 2005, and his M.S. and Ph.D. in Mechanical and Aeronautical Engineering from the University of California, Davis in 2010 and 2012, respectively. Dr. Loyola specializes in creating sensing methodologies for structural health monitoring applications, specifically using carbon nanotube thin films and electrical impedance tomography (EIT). Steven Paradise is a Senior Member of Technical Staff at Sandia National Laboratories in Livermore, California. Steven graduated Magna Cum Laude from the University of Utah in 2005 with a BS in Electrical Engineering, and earned his MS in Electrical Engineering the following year, studying nonlinear optical effects under Dr. Steve Blair. In 2006, he began working at Sandia and entered the selective Weapon Intern Program. Since then, he has developed and tested optical technology for use in national security applications, such as improving safety, security, and reliability of weapon systems. Christopher J. Hall is a Member of Technical Staff in Electrical Engineering at Sandia National Laboratories in Livermore, California. Chris graduated Magna Cum Laude from Utah State Univers
June 2nd, 2014
Stéphane Lafortune University of Michigan-Ann Arbor When: Wednesday, June 4, 2014 at 3:00 p.m.Where: Warnock 1250 Abstract We will present an overview of recent research trends in control and diagnosis of Discrete Event Systems (DES) that are motivated by challenges arising in cyber-physical systems. In the first part of the talk, we will review the basic theory of supervisory control of DES, discuss its connection with reactive synthesis in computer science, and present results on its application to the problem of collision avoidance in vehicular networks. In this application, the continuous dynamics of the vehicles are abstracted in a discrete-event model, where uncontrollable events capture unmodeled dynamics and unobservable events capture measurement uncertainty. In the second part of the talk, we will review the basic theory of fault diagnosis in partially-observed DES and then discuss recent work on enforcement of opacity, a class of properties studied in computer security. Opacity is essentially the dual of diagnosability. We will discuss how opacity enforcement techniques can be used to protect users' privacy in location-based services. Speaker Biographies Stéphane Lafortune is a Professor in the Department of Electrical Engineering and Computer Science at the University of Michigan, Ann Arbor. He obtained his degrees from Ecole Polytechnique de Montréal (B.Eng), McGill University (M.Eng), and the University of California at Berkeley (PhD), all in electrical engineering. Dr. Lafortune is a Fellow of the IEEE (1999). His research interests are in discrete event systems and include multiple problem domains: modeling, diagnosis, control, optimization, and applications to computer systems. He co-authored, with C. Cassandras, the textbook Introduction to Discrete Event Systems (2nd Edition, Springer, 2008). He is co-developer of the software packages DESUMA and UMDES.