Industrial and Systems Engineering

TITLE:   Data-driven Greedy Policies and Information-Relaxation Bounds for Ambulance Location and Deployment

SPEAKER:    Lavanya Marla (University of Illinois at Urbana-Champaign


Tuesday December 3, 2019
Mohler Lab, #453



We present an efficient data-driven computational solution and bounding approach for static allocation of an ambulance fleet and its dynamic redeployment, where the goal is to position (or re-position) ambulances to bases to maximize the system’s service level. Central to our approach is a discrete-event simulator to evaluate the impact of ambulance deployments to logs of emergency requests. We first model ambulance allocation as an approximately-submodular-maximization problem, and devise a simple and efficient greedy algorithm that produces both static allocations and dynamic repositioning policies. In parallel, we find data-driven information-relaxation bounds for both static and dynamic cases. We build even tighter information-relaxation bounds by penalizing the previous relaxations. Our approach allows the computation of tight bounds without incurring the curse of dimensionality common to such approaches. Our bounding methods help inform policymakers about the viability of proposed fleet sizes and policies being adopted by the contracted EMS agencies. Our computational experiments on an Asian city's EMS demonstrate the tractability and efficiency of our greedy algorithm and our bounding methods.

The first part of this work is with Ramayya Krishnan and Yisong Yue, and the latter part with Achal Bassamboo.


Lavanya Marla is an Assistant Professor in Industrial and Enterprise Systems Engineering at the University of Illinois at Urbana-Champaign. Prior to her current position, she was a Systems Scientist with the Heinz College at Carnegie Mellon University; and earned her PhD in Transportation Systems from MIT and Bachelors degree from IIT Madras. Her research interests are in robust and dynamic decision-making under uncertainty and game theoretic analysis for large-scale transportation and logistics systems; combining tools from data-driven optimization, statistics, simulation and machine learning. Her research is funded by an integrative National Science Foundation grant, a Department of Homeland Security cyber-security grant, the Department of Transportation, the US-India Educational Foundation, the INFORMS Transportation and Logistics Society and aviation companies. Her work has received an Honorable mention for the Anna Valicek award from AGIFORS, a best presentation award from AGIFORS, a KDD Startup Research award, and a Top-10 cited paper recognition from Transportation Research – Part A.



Past Events

Fall 2019
Tuesday, November 12, 2019 - 4:30pm
ISE Seminar Series - Kayse Maass, Northeastern University
"A Systems Approach to Disrupting Human Trafficking"
Tuesday, November 5, 2019 - 4:30pm
INFORMS Chapter Distinguished Speaker Series - Robert Vanderbei, Princeton University
"The Parametric Self-Dual Simplex Method — A Modern Perspective"
Tuesday, October 8, 2019 - 4:30pm
ISE Seminar Series - Miju Ahn, Southern Methodist University
"Learning with Difference-of-Convex Sparsity Functions"
Tuesday, September 17, 2019 - 4:30pm
ISE Seminar Series - Ramteen Sioshansi, The Ohio State University
"Can We Get Market and Regulatory Designs ‘Right’ for Energy Storage?"
Tuesday, September 10, 2019 - 4:30pm
ISE Seminar Series - Adam Elmachtoub, Columbia University
"Smart "Predict, then Optimize""
Spring 2019
Tuesday, May 7, 2019 - 4:00pm
ISE Seminar Series - Alec Koppel, U.S. Army Research Laboratory
"Policy Search for Reinforcement Learning in Continuous Spaces: Improved Limits and Reduced Variance"
Tuesday, April 9, 2019 - 4:00pm
ISE Seminar Series - Aida Khajavirad (Rutgers & NYU)
"Novel Polyhedral Relaxations for Mixed-Integer Polynomial Optimization Problems"
Tuesday, April 2, 2018 - 4:00pm
INFORMS Chapter Distinguished Speaker Series - Stefan Wild, Argonne National Laboratory
"Exploiting Structure in Derivative-Free Nonlinear Optimization to Advance Science and Engineering"
Tuesday, March 26, 2019 - 4:00pm
ISE Seminar Series - Clément Royer, University of Wisconsin-Madison
"Nonconvex Optimization via Newton-CG Methods with Complexity Guarantees"
Tuesday, March 19, 2019 - 4:00pm
ISE Seminar Series - William K. Klimack, Chevron
"Decision Analysis at Chevron"
Tuesday, March 5, 2019 - 4:00pm
ISE Seminar Series - James Luedtke, University of Wisconsin-Madison
"Optimizing Truck Dispatching Decisions in Open-pit Mining using Integer Programming"
Tuesday, February 12, 2019 - 4:00pm
ISE Seminar Series - J. Cole Smith, Clemson University
"The Maximum Semicontinuous Flow Problem"
Tuesday, January 29, 2019 - 4:00pm
ISE Seminar Series - Giacomo Nannicini, IBM T.J. Watson Research Center
"Fully Polynomial-Time Approximation Schemes for Stochastic Dynamic Programs: Theory and Applications"
Fall 2018
Tuesday, December 4, 2018 - 4:00pm
ISE Seminar Series - Andreas Wächter, Northwestern University
"Nonlinear Programming Formulations of Chance-Constraints"
Tuesday, November 27, 2018 - 4:00pm
INFORMS Chapter Distinguished Speaker Series - Gerard Cornuejols, Carnegie Mellon University
"Packing and Covering"
Tuesday, November 13, 2018 - 4:00pm
ISE Seminar Series - Mert Gürbüzbalaban, Rutgers University
"Momentum Acceleration Under Random Gradient Noise: From Convex to Non-Convex Optimization"
Tuesday, October 30, 2018 - 4:00pm
ISE Seminar Series - Michael Katehakis, Rutgers University
"Reinforcement Learning: Connections Between MDPs and MAB Problems"
Tuesday, October 2, 2018 - 4:00pm
ISE Seminar Series - Michael L. Overton, Courant Institute of Mathematical Sciences, NYU
"Nonsmooth, Nonconvex Optimization: Algorithms and Examples"
Spring 2018
Tuesday, May 8, 2018 - 4:00pm
ISE Seminar Series - Krzysztof Choromanski, Google
"Structure is all that you need - Learning Compressed RL Policies Via Orthogonal Gradient Sensing"
Tuesday, May 1, 2018 - 4:00pm
ISE Seminar Series - Henry Lam, Columbia University
"Assessing Solution Quality in Stochastic Optimization with Limited Data"
Tuesday, April 24, 2018 - 4:00pm
INFORMS Chapter Distinguished Speaker Series - James Renegar, Cornell University
"A Simple Nearly-Optimal Restart Scheme for Speeding-Up First Order Methods"
Thursday, April 19, 2018 - 4:00pm
ISE Seminar Series - Matthias Walter, RWTH Aachen University
"Investigating Polyhedra by Oracles"
Tuesday, April 10, 2018 - 4:00pm
ISE Seminar Series - Stefano Coniglio, University of Southampton
"Network Routing Through the Internet as a Stackelberg Game"
Tuesday, March 6, 2018 - 4:00pm
ISE Seminar Series - Bo Zeng, University of Pittsburgh
"Robust and Chance Constrained Optimization in Power and Logistics Systems"
Fall 2017
Tuesday, December 5, 2017 - 4:00pm
ISE Seminar Series - Garud Iyengar, Columbia University
"Automatic Event Detection in Basketball"
Thursday, November 30, 2017 - 4:00pm
Spencer C. Schantz Technical Lecture - William J. Cook, University of Waterloo
"Guiding the Cutting-Plane Method"
Wednesday, November 29, 2017 - 4:00pm
Spencer C. Schantz Distinguished Lecture Series Presents William J. Cook
"In Pursuit of the Traveling Salesman: Mathematics at the Limits of Computation"
Tuesday, November 14, 2017 - 4:00pm
ISE Seminar Series - Jonathan Eckstein, Rutgers University
"Asynchronous Projective Splitting for Convex Optimization and Monotone Inclusion Problems"
Tuesday, November 7, 2017 - 4:00pm
ISE Seminar Series - Osman Y. Ozaltin, North Carolina State University
"A Branch-and-cut Algorithm for Discrete Bilevel Linear Programs"
Tuesday, October 31, 2017 - 4:00pm
ISE Seminar Series - Oleg Prokopyev, University of Pittsburgh
"Sequential Max-Min Bilevel Linear Programming with Incomplete Information and Learning"
Tuesday, October 10, 2017 - 4:00pm
ISE Seminar Series - Ion Necoara, University Politehnica of Bucharest
"Conditions for Linear Convergence of (Stochastic) First Order Methods"
Thursday, October 5, 2017 - 4:00pm
INFORMS Chapter Distinguished Speaker Series: Nick Trefethen, University of Oxford
Tuesday, September 26, 2017 - 4:00pm
ISE Seminar Series - Andrew Dorsett, Wolfram Research
"Mathematica 11 in Education and Research"
Tuesday, September 19, 2017 - 4:00pm
ISE Seminar Series - Alejandro Ribeiro, University of Pennsylvania
"High Order Methods in Empirical Risk Minimization"
Tuesday, August 22, 2017 - 4:00pm
ISE Seminar Series - Giorgio Fasano, Thales Alenia Space
"Solving Non-Standard Packing Problems by Global Optimization and Heuristics"