Chronological  By Speaker  


Title  HighSpeed Magnetically Levitated Trains 
Speaker  Ernest Mendrela 
Department of Electrical and Computer Engineering Louisiana State University  
Abstract  The purpose of developing highspeed Magnetically Levitated (MAGLEV) trains is to fill the gap between conventional trains and short distance airplanes in the transport system. In conventional railway trains, the rails and wheels give suspension, guidance and drive. Since the MAGLEV trains have no mechanical contact with the track, these three tasks are fulfilled by the magnetic field. The presentation will focus on the basic concept of MAGLEV trains and a historical review of the research carried out in most developed countries with particular emphasis on German series TRANSRAPID trains. The last version of this series has been built in Shanghai as the world's first commercially used highspeed MAGLEV trains. 
When  Tuesday, 8 September 2009, 10:00  11:00 
Where  117 Electrical Engineering Building 
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Title  Logical Foundation of Reasoning and Inference 
Speaker  X. Rong Li 
Department of Electrical Engineering, University of New Orleans  
Abstract  A clear mind is a logical mind. This talk may make your mind clearer and, in the meantime, more confused. Not only do we elucidate the pillars of logic, which helps sharpen your logical thinking, but we also bring your attention to subtle logical fallacies in the hope of freeing your reasoning from such problems. An emphasis is on probabilistic reasoning, which forms the underpinnings of the entire scientific edifice. On the other hand, the talk may force you to puzzle over mindboggling paradoxes rooted deeply in logic. We reveal one of the best kept and most shocking secrets: the fundamental law of inference, albeit a logical truth, can hardly be accepted by rational people, including you. We discuss an alternative in terms of randomset theoryâ€”a powerful mathematical tool particularly promising for information fusion. Relevant developments in recent years are covered briefly. An attempt is made to drive home the point that a more downtotheearth logic than the existing deductive logic, which is ideal rather than realistic, should be developed. 
When  Wednesday, 16 September 2009, 15:00  16:00 
Where  117 Electrical Engineering Building 
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Title  The Local View in Networks 
Speaker  Ashu Sabharwal 
Rice University  
Abstract  A key element of mobile wireless networks is their distributed nature, which implies that often nodes only have a local view of the network. This leads to a situation where the ground truth for each node is different from other nodes. As a result, nodes have to make distributed decisions about their transmission parameters like rate and power to maximize global spectral efficiency. Our driving question is "How well do distributed decisions perform compared to centralized decisions?" In this talk, we will first formulate a messagepassing protocol which allows the information about the network to trickle via local message forwarding. The protocol naturally gives rise to networks where nodes have different amount of local information. We will then study distributed rateallocation policies and analyze their performance in some worst case topologies. The analysis systematically captures the extent of loss in network capacity which is incurred when nodes make decisions based on a local view of the network. Further, we will classify the topologies which are distributed decision friendly. The analysis sheds light on achievable capacity of different network protocols for classic hiddennode topologies. Towards the end of the talk, we will shift gears and discuss emerging concepts in design, implementation and experimentation of cleanslate wireless protocols. With focus on deployed programmable networks, we will describe the main elements of opensource WARP project. Three main design flows will be discussed: WARP frameworks for atspeed tests, WARPLab for MATLABbased overtheair experiments and WARPnet for deployed operational networks. 
When  Wednesday, 7 October 2009, 10:00  11:00 
Where  117 Electrical Engineering Building 
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Title  Wireless NetworkonChip: A New Communication Paradigm for Gigascale Heterogeneous MCSoCs 
Speaker  Danella Zhao 
Center for Advanced Computer Studies  
Abstract  Manycore SystemonChip (MCSoC) designs are rapidly emerging, where hundreds or even thousands of IP cores are integrated on a single die. Such MCSoC devices allow superior performance gains while sidestepping the power and heat dissipation limitations of clock frequency scaling. The main advantage lies in the exploitation of parallelism, distributively and massively. Consequently, the onchip communication fabric becomes the performance determinant. To bridge the widening gap between computation requirements and communication efficiency faced by gigascale heterogeneous MPSoCs in the upcoming billiontransistor era, a new onchip communication system, dubbed Wireless NetworkonChip (WNoC), has been proposed by using the recently developed RF interconnect technology. With the uniqueness of wireless interconnection, the WNoC design paradigm calls for effective solutions to overhaul the onchip communication infrastructure of nanoscale MPSoCs. In this talk, I will present the feasibility study of WNoC from various aspects, physical layer exploration, system architecture design, RF microarchitecture development and hardware implementation. 
When  Wednesday, 14 October 2009, 14:00  15:00 
Where  117 Electrical Engineering Building 
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Title  Constructions of Strict Lyapunov Functions: An Overview 
Speaker  Michael Malisoff 
LSU Department of Mathematics  
Abstract  Mathematical control theory provides the theoretical foundations that undergird many modern technologies, including aeronautics, biotechnology, communications networks, manufacturing, and models of climate change. During the past fifteen years, there have been numerous exciting developments at the interface of control engineering and mathematical control theory. Many of these advances were based on new Lyapunov methods for analyzing and stabilizing nonlinear systems. Constructing strict Lyapunov functions is a central and challenging problem. On the other hand, nonstrict Lyapunov functions are often constructed easily, using passivity, backstepping, or forwarding, or by taking the Hamiltonian for EulerLagrange systems. Roughly speaking, nonstrict Lyapunov functions are characterized by having negative semidefinite time derivatives along all trajectories of the system, while strict Lyapunov functions have negative definite derivatives along the trajectories. Even when we know a system to be globally asymptotically stable, it is often still important to have an explicit global strict Lyapunov function, e.g., to design feedbacks that give inputtostate stability to actuator errors. One important research topic involves finding necessary and sufficient conditions for different kinds of stability, in terms of the existence of Lyapunov functions, such as Lyapunov characterizations for hybrid systems, or for systems with measurement uncertainty and outputs. Some of the most significant recent work in this direction has been carried out by Andrew Teel and his coworkers, who employ systems on hybrid time domains that encompass continuous time and discrete time systems as special cases. Converse Lyapunov function theory implies the existence of strict Lyapunov functions for large classes of globally asymptotically stable nonlinear systems. However, the Lyapunov functions given by converse theory are often abstract or nonexplicit, and so may not always lend themselves to feedback design. Explicit strict Lyapunov functions are also important for quantifying the effects of uncertainty, because, e.g., they can be used to build the comparison functions in the inputtostate stability estimate. In fact, once we construct a suitable global strict Lyapunov function, several significant stabilization and robustness problems can be solved almost immediately, using standard arguments. In some situations, nonstrict Lyapunov functions are enough, because they can be used in conjunction with LaSalle Invariance or Barbalat's Lemma to show global asymptotic stability. In other cases, it suffices to analyze the system around a reference trajectory, or near an equilibrium point, so linearizations having simple local quadratic Lyapunov functions apply. However, it is now well appreciated that linearizations and nonstrict Lyapunov functions are insufficient to analyze general timevarying nonlinear systems. Nonstrict Lyapunov functions are not well suited for robustness analysis, because their negative semidefinite time derivatives along the trajectories could become positive under small uncertainties of the system. Uncertainties usually arise in applications, because of unknown model parameters, or noise entering controllers. For this reason, inputtostate stability and other robustness proofs often rely on finding global strict Lyapunov functions. Also, there are important classes of nonlinear systems (such as chemostat models) that often evolve far from their equilibria. This has motivated a significant body of research on ways to explicitly construct strict Lyapunov functions. One approach to designing explicit strict Lyapunov functions, which has received a lot of attention in the past few years, is the socalled strictification approach. This entails transforming given nonstrict Lyapunov functions into explicit global strict Lyapunov functions, under appropriate nondegeneracy conditions on the nonstrict Lyapunov function. The approach has been successfully employed in many contexts, including adaptive control, Hamiltonian systems satisfying the conditions from the JurdjevicQuinn theorem, and timevarying hybrid dynamical systems with mixtures of continuous and discrete time evolutions. Strictification reduces difficult strict Lyapunov function construction problems to oftentimes much simpler nonstrict Lyapunov function construction problems. This talk will present an overview of the strictification approach for systems satisfying the conditions from Matrosov's Theorem, which express the nondegeneracy of the nonstrict Lyapunov function in terms of auxiliary scalar functions. The simplicity of our strict Lyapunov function constructions makes them suitable for quantifying the effects of uncertainty, and for feedback design. We illustrate our work using two important biotechnological examples, the first involving anaerobic digesters and the second involving LotkaVolterra systems. 
When  Tuesday, 27 October 2009, 10:00  11:00 
Where  117 Electrical Engineering Building 
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Title  New Lyapunov Function Methods for Adaptive and TimeDelayed Systems 
Speaker  Michael Malisoff 
LSU Department of Mathematics  
Abstract  Lyapunov functions are an important tool in nonlinear control systems theory. This talk presents new Lyapunovbased adaptive tracking control results for nonlinear systems in feedback form with multiple inputs and unknown highfrequency control gains. Our adaptive controllers yield uniform global asymptotic stability for the error dynamics, which implies parameter estimation and tracking for the original systems. We demonstrate our work using a tracking problem for a brushless DC motor turning a mechanical load. Then we present a new class of dilution rate feedback controllers for twospecies chemostat models with Haldane uptake functions where the species concentrations are measured with an unknown time delay. 
When  Tuesday, 4 May 2010, 15:00  16:00 
Where  117 Electrical Engineering Building 
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