10/17/24 | 4:15pm | E51-149
Jean Pauphilet
Assistant Professor, Management Science and Operations
London Business School
Abstract: Millions of tons of plastic are poured in the seas every year, damaging entire ecosystems from the coastlines up to the open waters. We partner with a non-profit organization and use optimization to help clean up oceans from plastic faster. Specifically, we optimize the route of their plastic collection system in the ocean to maximize the quantity of plastic collected over time. We formulate the problem as a longest path problem in a well-structured graph. However, since collection directly impacts future plastic density, the corresponding edge lengths are non-linear polynomials. After analyzing the structural properties of the edge lengths, we propose a search-and-bound method, which leverages a relaxation of the problem solvable via dynamic programming and clustering, to efficiently find high-quality solutions (within 6%-optimal in practice), and develop a tailored branch-and-bound strategy to solve it to provable optimality. On one-year of ocean data, our optimization-based routing approach increases the quantity of plastic collected by over 60% compared with their current routing strategy, hence speeding up the progress towards plastic-free oceans.
Bio: Jean is an assistant professor of Management Science and Operations at London Business School. His research sits at the intersection of discrete optimization, robust optimization, and machine learning, with applications to healthcare and sustainable operations. His work has been recognized by multiple awards, including the 2020 INFORMS George E. Nicholson and the 2021 INFORMS Pierskalla awards.