Posted September 19, 2024
5:30 pm James E. Keisler Lounge (room 321 Lockett)Actuarial Student Association Meeting
We will have a guest visitor Aimee Milam from CareSource. Pizza will be served.
Posted August 30, 2024
Last modified September 16, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Rachel Meyers, Louisiana State University
TBD
Posted September 15, 2024
7:50 am – 2:00 pm Virtually via Zoom, Click here to join Zoom, Meeting ID: 894 8105 1822, Passcode: SIIT-LSU24SIIT-LSU Conference on Analysis and PDE In Honor of Igor E. Verbitsky’s Retirement
This is an Analysis and PDE international joint conference between LSU and Sirindhorn International Institute of Technology (SIIT), Thailand, in honor of Professor Igor E. Verbitsky’s Retirement. The conference will take place virtually via Zoom and everyone is invited to participate. All the conference materials are now available on the conference website: https://sites.google.com/view/siit-lsu/
Posted August 27, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Jean Auriol, CNRS Researcher, L2S, CentraleSupélec
Robust Stabilization of Networks of Hyperbolic Systems with Chain Structure
In this talk, we focus on recent developments for the stabilization of networks of elementary hyperbolic systems with a chain structure. Such a structure arises in multiple industrial processes such as electric power transmission systems, traffic networks, or torsional vibrations in drilling devices. The objective is to design feedback control laws that stabilize the chain using the available actuators and sensors. The different systems composing the network are called elementary in the sense that when taken alone, we know how to design stabilizing output-feedback control laws. We will first consider the case where the actuators and sensors are available at one end of the chain. Using appropriate state predictors, we will present a recursive approach to stabilize the whole chain. Then, we will focus on the case where the actuators and sensors are only available at the junction between two subsystems composing the chain. We will show that such a configuration does not always guarantee the controllability of the chain. Under appropriate controllability/observability conditions, we will design simple stabilizing control laws. Our approach will be based on rewriting the system as Integral Delay Equations (IDEs) with pointwise and distributed control terms. Finally, we will show how the proposed techniques can be used to develop output feedback control laws for traffic flow on two cascaded freeway segments connected by a junction.
Posted September 19, 2024
1:30 pm – 2:30 pm Keisler LoungeMeet & Greet with Jon Loftin (MathWorks)
Pizza will be served. Jon Loftin will present on "Deep Learning with MATLAB: A Visual Approach" after the lunch.
Posted September 17, 2024
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Zoom Link
Matthew Kroeker, Waterloo
Unavoidable flats in matroids representable over a finite field
For a positive integer k and finite field F, we prove that every simple F-representable matroid with sufficiently high rank has a rank-k flat which either is independent, or is a projective or affine geometry over a subfield of F. As a corollary, we obtain the following Ramsey theorem: given an F-representable matroid of sufficiently high rank and any 2-colouring of its points, there is a monochromatic rank-k flat. This is joint work with Jim Geelen and Peter Nelson.
Posted September 19, 2024
2:30 pm – 3:30 pm Lockett 284Deep Learning with MATLAB: A Visual Approach
Deep learning is quickly becoming embedded in everyday applications. It’s becoming essential for students and educators to adopt this technology to solve complex real-world problems. MATLAB and Simulink provide a flexible and powerful platform to develop and automate data analysis, deep learning, AI, and simulation workflows in a wide range of domains and industries. In this workshop we will introduce deep learning with MATLAB. We will utilize a previously trained network and modify it, using the MATLAB Deep Network Designer. The Deep Network Designer allows you to interactively build, visualize, and train neural networks. Individuals can generate the code for the neural network and finetune parameters. Users can use popular pre-trained networks or construct their own. We will also look at the MATLAB Classification Learner to run several models on a single data set. These visual approaches create a more efficient workflow.
Posted August 30, 2024
Last modified September 16, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Nilangshu Bhattacharyya, Louisiana State University
TBD
Posted September 18, 2024
3:30 pm Lockett 237
Ian Tobasco, Rutgers University
Rigidity and Elasticity
This talk will introduce elasticity theory from the geometric point of view for students from mathematics and related disciplines. Our basic objects of study will be (nearly) length preserving maps that arise from (nearly) minimizing an energy functional having to do with the amount of work required to deform a body. After defining the basic quantities of interest, we will discuss Fritz John's seminal study of small strain maps, along with his counterexample to rigidity and its ultimate resolution in the early 2000s by Friesecke, James, and Müller. Time permitting, we will discuss a bit about elastic patterns --- fine structures that occur in naturally wrinkled or crumpled sheets that show us what we do not yet understand about the rigidity of thin elastic domains.
Posted July 13, 2024
Last modified September 16, 2024
Colloquium Questions or comments?
3:30 pm Lockett 232
Ian Tobasco, Rutgers University
Homogenization of Kirigami and Origami-Based Mechanical Metamaterials
Mechanical metamaterials are many-body elastic systems that deform in unusual ways, due to the interactions of nearly rigid building blocks. Examples include origami patterns with many folds, or kirigami patterns made by cutting material from an elastic sheet. In either case, the local deformations of the pattern involve internal degrees of freedom which must be matched with the usual global Euclidean invariances --- e.g., groups of origami panels move by rotations and translations while the whole pattern bends into a curved shape. This talk will introduce the homogenization problem for kirigami and origami metamaterials to a broad audience, and describe our recent results. Our goal is to explain the link between the design of the individual cuts/folds and the bulk deformations they produce. This is joint work with Paul Plucinsky (U. Southern California, Aerospace and Mechanical Engineering) and Paolo Celli (Stony Brook U., Civil Engineering). This talk will be mathematically self-contained, not assuming a background in elasticity.
Posted August 11, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Panagiotis Tsiotras, Georgia Institute of Technology
AIAA and IEEE Fellow
TBA
Posted August 28, 2024
Combinatorics Seminar Questions or comments?
2:30 pm – 3:30 pm Zoom (Please email zhiyuw at lsu.edu for Zoom link)
Ce Chen, University of Illinois Urbana-Champaign
On the maximum $F$-free induced subgraphs in $K_t$-free graphs
For graphs $F$ and $H$, let $f_{F,H}(n)$ be the minimum possible size of a maximum $F$-free induced subgraph in an $n$-vertex $H$-free graph, which is a generalization of both the Ramsey function and the Erd\H{o}s--Rogers function. Assuming the existence of certain locally dense $H$-free graphs, we give a general upper bound on $f_{F,H}(n)$ by establishing a container lemma for the $F$-free subgraphs. In particular, we improve the upper bounds on $f_{F,H}(n)$ when H is $K_3$ and $K_4$. This is joint work with J\'{o}zsef Balogh and Haoran Luo.
Posted August 21, 2024
Last modified August 29, 2024
Algebra and Number Theory Seminar Questions or comments?
2:30 pm – 3:30 pm Lockett 233 or click here to attend on Zoom
Wanlin Li, Washington University in St. Louis
TBA
Posted August 30, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Krishnendu Kar, Louisiana State University
TBD
Posted July 11, 2024
Faculty Meeting Questions or comments?
3:30 pm – 4:30 pm tbaCollege of Science Fall Convocation
Posted September 11, 2024
Last modified September 18, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Rushikesh Kamalapurkar, University of Florida
Operator Theoretic Methods for System Identification
Operator representations of dynamical systems on Banach spaces provide a wide array of modeling and analysis tools. In this talk, I will focus on dynamic mode decomposition (DMD). In particular, new results on provably convergent singular value decomposition (SVD) of total derivative operators corresponding to dynamic systems will be presented. In the SVD approach, dynamic systems are modeled as total derivative operators that operate on reproducing kernel Hilbert spaces (RKHSs). The resulting total derivative operators are shown to be compact provided the domain and the range RKHSs are selected carefully. Compactness is used to construct a novel sequence of finite rank operators that converges, in norm, to the total derivative operator. The finite rank operators are shown to admit SVDs that are easily computed given sample trajectories of the underlying dynamical system. Compactness is further exploited to show convergence of the singular values and the right and left singular functions of the finite rank operators to those of the total derivative operator. Finally, the convergent SVDs are utilized to construct estimates of the vector field that models the system. The estimated vector fields are shown to be provably convergent, uniformly on compact sets. Extensions to systems with control and to partially unknown systems are also discussed. This talk is based in part on joint works [RK23], [RK24], and [RRKJ24] with J.A. Rosenfeld.
Posted August 30, 2024
Last modified September 16, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Adithyan Pandikkadan, Louisiana State University
TBD
Posted August 29, 2024
Geometry and Topology Seminar Seminar website
3:30 pm
Bin Sun, Michigan State University
TBD
Posted August 14, 2024
Algebra and Number Theory Seminar Questions or comments?
Brian Grove, LSU
TBA
Posted August 30, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Megan Fairchild, Louisiana State University
TBD
Posted August 19, 2024
Last modified September 6, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Andrii Mironchenko, University of Klagenfurt
IEEE CSS George S. Axelby Outstanding Paper Awardee
TBA
Posted August 21, 2024
Last modified August 29, 2024
Algebra and Number Theory Seminar Questions or comments?
2:30 pm – 3:30 pm Lockett 233 or click here to attend on Zoom
Brett Tangedal, University of North Carolina, Greensboro
TBA
Posted August 30, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Matthew Lemoine, Louisiana State University
TBD
Posted August 26, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Angelia Nedich, Arizona State University
TBA
Posted August 30, 2024
Last modified September 16, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Nilangshu Bhattacharyya, Louisiana State University
TBD
Posted September 6, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Laura Menini, Università degli Studi di Roma Tor Vergata
TBA
Posted August 30, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Sean Boros, Louisiana State University
TBD
Posted September 17, 2024
Geometry and Topology Seminar Seminar website
3:30 pm Lockett 233
Arka Banerjee, Auburn University
TBD
Posted August 29, 2024
Last modified September 12, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Piernicola Bettiol, Université de Bretagne Occidentale, France
TBA
Posted September 11, 2024
Applied Analysis Seminar Questions or comments?
3:30 pm Lockett 232
Michael Novack, Louisiana State University
TBA
Posted August 30, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Saumya Jain, Louisiana State University
TBD
Posted August 21, 2024
Last modified September 12, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Benedetto Piccoli, Rutgers University, Camden
AMS Fellow, SIAM W. T. and Idalia Reid Prize Awardee
Control Theory in Traffic Applications: 100 Years of Traffic Models
In 1924, in The Quarterly Journal of Economics, Frank H. Knight debated on social costs using an example of two roads, which was the base of the Wardrop’s principle. The author suggested the use of road tolls and it was probably the first traffic model ever. A few other milestones of a long history include the traffic measurements by Greenshields in 1934, the Lighthill-Whitham-Richards model in late 1950s, and follow-the-leader microscopic models. After describing some of these milestones, we will turn to modern theory of conservation laws on topological graphs with application to traffic monitoring. The theory required advance mathematics such as BV spaces and Finsler-type metrics on L1. In the late 2000s, this theory was combined with Kalman filtering to deal with traffic monitoring using data from cell phones and other devices. Then we will turn to measure-theoretic approaches for multi-agent systems, which encompass follow-the-leader-type models. Tools from optimal transport allow us to deal with the mean-field limit of controlled equations, representing the action of autonomous vehicles. We will conclude by discussing how autonomy can dissipate traffic waves and reduce fuel consumption, then illustrating the results of a 2022 experiment with 100 autonomous vehicles on an open highway in Nashville.
Posted August 29, 2024
Algebra and Number Theory Seminar Questions or comments?
2:30 pm – 3:30 pm Lockett 233 or click here to attend on Zoom
Jiuya Wang, University of Georgia
TBA
Posted August 30, 2024
Informal Geometry and Topology Seminar Questions or comments?
1:30 pm Locket 233
Huong Vo, Louisiana State University
TBD
Posted August 13, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
Karl Johansson, KTH Royal Institute of Technology, Sweden
Fellow of IEEE, IEEE CSS Hendrik W. Bode Lecture Prize Awardee
TBA
Posted September 4, 2024
Control and Optimization Seminar Questions or comments?
10:30 am – 11:20 am Zoom (click here to join)
María Soledad Aronna, Escola de Matematica Aplicada, Brazil
TBA
Posted September 19, 2024
Colloquium Questions or comments?
3:30 pm Lockett 232
Bogdan Suceava, California State University Fullerton
TBD