The Center for Healthcare Operations Improvement and Research (CHOIR) at the University of Twente announces the 38th talk in the ORAHS International Seminar Series.
The ORAHS International Seminars are planned via MS Teams in the late afternoon (Europe), morning (US), or evening (Asia/Pacific) and are part of the EURO Online Seminar Series.
On 23 June 2026, at 16:00 (CEST), Dr. Miguel Lejeune (George Washington University, USA) will talk about “Emergency Network Design for Opioid Drug Overdoses: Exact Reformulations and Algorithms for Queuing-Based Optimization Models”.
Please save the date and register for this seminar here:
https://events.teams.microsoft.com/event/f35f8531-6bb3-4afb-b7ad-4fb79185dbf6@723246a1-c3f5-43c5-acdc-43adb404ac4d
Abstract: In the joint work with Wenbo Ma, we study queueing-based nonconvex optimization models to design networks in which time is of the essence and the objective is to minimize the response time. The problem is motivated and applied for the drone-based delivery of narcan in case of opioid overdoses. The network is modelled as a collection of queueing systems in which the service times and the arrival of requests are random variables whose distribution parameters are determined endogenously. The optimization model takes the form of a nonconvex integer problem with fractional, exponential, and polynomial terms for which we propose (i) a mixed-integer linear programming reformulation framework and (ii) an algorithmic approach involving an outer approximation method and a new family of nested valid inequalities. Numerical tests based on real-data for the city of Virginia Beach will be presented.
Bio: Miguel Lejeune is a Full Professor of Decision Sciences at the George Washington University. His areas of expertise include stochastic programming, distributionally robust optimization, decision-dependent uncertainty and mixed-integer nonlinear programming. His application areas include health care, wildfire risk, power systems, financial risk, supply chain, disaster management, and military operations. His current research is funded by several grants from the National Science Foundation and the DUKE Energy Innovation Fund. Dr. Lejeune is the recipient of the 2019 Koopman Award of the INFORMS Society, the 2024 Excellence Research Award in Applied Mathematics from the Washington Academy of Science, a CAREER Research Grant from the Army Research Office, and the IBM Smarter Planet Faculty Innovation Award. Dr. Lejeune is a Fellow of the Washington Academy of Science.
More information about our speaker can be found here:
https://business.gwu.edu/miguel-lejeune
For more information about our seminar presentations, please follow this link:
https://www.utwente.nl/en/choir/research/ORAHS-International-Seminar-Series/
We look forward to seeing you soon and often in the ORAHS International Seminar Series.
CHOIR Group
University of Twente