This page is no longer being updated. For more recent control-related activities, see https://www.math.lsu.edu/research/controltheory. For more information, check the LSU mathematics department calendar. Recent conferences, departmental seminars, and workshops involving the LSU control and optimization group included the following:
- December 12-14, 2007, Hilton New Orleans Riverside in New Orleans, LA: 46th IEEE Conference on Decision and Control.
- July 26-27, 2007, LSU: Workshop on Control Theory and Mathematical Biology. Speakers will include Azmy Ackleh, Patrick De Leenheer, and Frederic Mazenc.
- July 11-13, 2007, Marriott Marquis Hotel at Times Square, New York City: 2007 American Control Conference. Remark: This conference included two talks by a control group member that received Best Presentation Awards.
- May 22-31, 2007, LSU: Louisiana Workshop on Mathematical Control Theory (MCT'07). Piermarco Cannarsa will be a featured speaker. Other confirmed participants include Antonio Marigonda and Vinicio Rios. Other invited speakers include Yuri Ledyaev and Francis Clarke. A full program will be available soon.
- Wednesday, May 2, 2007, 11:40AM-12:30PM in 239 Lockett, LSU: Speaker: Peter Wolenski, LSU Department of Mathematics. Title: The Role of Convexity in Optimization and Control Theory (Part III). Abstract: This will be a continuation of Wolenski's April 25th lecture.
- Wednesday, April 25, 2007, 11:40AM-12:30PM in 239 Lockett, LSU: Speaker: Peter Wolenski, LSU Department of Mathematics. Title: The Role of Convexity in Optimization and Control Theory (Part II). Abstract: This will be a continuation of Wolenski's April 18th lecture.
- Wednesday, April 18, 2007, 11:40AM-12:30PM in 239 Lockett, LSU: Speaker: Peter Wolenski, LSU Department of Mathematics. Title: The Role of Convexity in Optimization and Control Theory. Abstract: This talk will broadly survey the role of convexity in optimization theory, and outline its special place in optimal control. Roughly speaking, convexity plays the role in optimization analogous to that enjoyed by linearity in dynamical system theory. We shall illustrate this by discussing the features of local vs. global statements, generalized differentiation, duality, and representation formulas.
- Wednesday, April 11, 2007: No seminar. Reason: Peter Wolenski participated in the MSRI Symposium on Climate Change: From Global Models to Local Action.
- Wednesday, March 28, 2007, 11:40AM-12:30PM in 239 Lockett, LSU: Speaker: Feng Gao (Graduate Student), LSU Department of Mechanical Engineering. Title: A Generalized Approach for the Control of MEM Relays. Abstract: We show that voltage-controlled, electrostatic and electromagnetic micro-relays have a common dynamic structure. As a result, both types of microelectromechanical (MEM) relays are subject to the nonlinear phenomenon known as pull-in, which is usually associated with the electrostatic case. We show that open-loop control of MEM relays naturally leads to pull-in during the relay closing. Two control schemes - a Lyapunov design and a feedback linearization design - are presented with the objectives of avoiding pull-in during the micro-relay closing and improving the transient response during the micro-relay opening. Simulations illustrate the performance of the two control schemes in comparison to the typical open-loop operation of the MEM relay.
- Wednesday, March 21, 2007: No seminar. Reason: 2007 Clifford Conference Nonlinear PDEs: Analysis, Numerics, and Applications at Tulane.
- Wednesday, March 7, 2007, 11:40AM-12:30PM in 239 Lockett, LSU
Speaker: Jimmie Lawson, LSU Department of Mathematics
Title: The Symplectic Group and Semigroup and Riccati Differential Equations (Part III)
Abstract: This is a continuation of Lawson's February 28th control seminar. - Wednesday, February 28, 2007, 11:40AM-12:30PM in 239 Lockett, LSU
Speaker: Jimmie Lawson, LSU Department of Mathematics
Title: The Symplectic Group and Semigroup and Riccati Differential Equations (Part II)
Abstract: This is a continuation of Lawson's February 14th control seminar. - Wednesday, February 21, 2007: No seminar due to Mardi Gras holiday.
- Wednesday, February 14, 2007, 11:40AM-12:30PM in 239 Lockett, LSU
Speaker: Jimmie Lawson, LSU Department of Mathematics
Title: The Symplectic Group and Semigroup and Riccati Differential Equations (Part I)
Abstract: We develop close connections between the important control-theoretic matrix Riccati differential equation and the symplectic matrix group and its symplectic subsemigroup. We use this example as a case study to demonstrate how the Lie theory of the subsemigroups of a matrix group can be applied to problems in geometric control theory. As an application we derive from this viewpoint the existence of a solution for the Riccati equation for all nonnegative t under quite general hypotheses. - Wednesday, February 7, 2007, 11:40AM-12:30PM in 239 Lockett, LSU
Speaker: Michael Malisoff, LSU Department of Mathematics
Title: Further Results on Lyapunov Functions for Slowly Time-Varying Systems
Abstract: We provide general methods for explicitly constructing strict Lyapunov functions for fully nonlinear slowly time-varying systems. Our results apply to cases where the given dynamics and corresponding frozen dynamics are not necessarily exponentially stable. This complements our previous Lyapunov function constructions for rapidly time-varying dynamics. We also explicitly construct input-to-state stable Lyapunov functions for slowly time-varying control systems. We illustrate our findings by constructing explicit Lyapunov functions for a pendulum model, an example from identification theory, and a perturbed friction model. This talk is based on the speaker's joint work with Frederic Mazenc. - Wednesday, January 31, 2007, 11:40AM-12:30PM in 301D Lockett, LSU
Speaker: Michael Malisoff, LSU Department of Mathematics
Title: On the Stability of Periodic Solutions in the Perturbed Chemostat
Abstract: We study the chemostat model for one species competing for one nutrient using a Lyapunov-type analysis. We design the dilution rate function so that all solutions of the chemostat converge to a prescribed periodic solution. In terms of chemostat biology, this means that no matter what positive initial levels for the species concentration and nutrient are selected, the long-term species concentration and substrate levels closely approximate a prescribed oscillatory behavior. This is significant because it reproduces the realistic ecological situation where the species and substrate concentrations oscillate. We show that the stability is maintained when the model is augmented by additional species that are being driven to extinction. We also give an input-to-state stability result for the chemostat-tracking equations for cases where there are small perturbations acting on the dilution rate and input nutrient concentration. This means that the long-term species concentration and substrate behavior enjoys a highly desirable robustness property, since it continues to approximate the prescribed oscillation up to a small error when there are small unexpected changes in the dilution rate function. This talk is based on the speaker's joint work with Frederic Mazenc and Patrick De Leenheer. - Wednesday, January 24, 2007, 1PM in 381 Lockett, LSU
Organizational Meeting for Control Seminar - December 13-15, 2006, San Diego, CA
45th IEEE Conference on Decision and Control (CDC'06)
Remark: This meeting included 3 presentations by a member of the control group who also chaired one CDC06 session. - June 5-9, 2006, Rome, Italy
Geometric Control and Nonsmooth Analysis (GCNA'06) - May 16-25, 2006, LSU
Louisiana Workshop on Mathematical Control Theory (MCT'06) - June 15-18, 2004, The Weizmann Institute of Science, Rehovot, Israel
Workshop on Variational Limits - April 10-13, 2003, LSU
Louisiana Conference on Mathematical Control Theory (MCT'03) - December 10-13, 2002, Venetian Hotel, Las Vegas, NV
Nonsmooth Analytic Methods in Control Theory I-II, Invited Sessions at 41st IEEE CDC - March 30-31, 2001, University of Kansas, Snow 554, Lawrence, KS
Special Sessions I-IV on Optimal Control, Stabilization, and Nonsmooth Analysis
2001 American Mathematical Society Central Section Meeting - Earlier Control Seminars at LSU