TALK    [MERL Seminar Series 2025] Dick den Hertog presents talk titled Optimizing the Path Towards Plastic-Free Oceans

Date & Time:

Tuesday, March 11, 2025; 12:00 PM

Abstract:

Increasing ocean plastic pollution is irreversibly harming ecosystems and human economic activities. We partner with a nonprofit 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, because collection directly impacts future plastic density, the corresponding edge lengths are nonlinear 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 more than 60% compared with the current routing strategy, hence speeding up the progress toward plastic-free oceans.

Speaker:

Dick den Hertog
University of Amsterdam

Dick den Hertog is professor of Operations Research at University of Amsterdam. His research interests cover various fields in prescriptive analytics, in particular linear and nonlinear optimization. In recent years, his main focus has been on robust optimization, and recently he started research on Optimization with Machine Learning. He is also active in applying the theory in real-life applications. In particular, he is interested in applications that contribute to a better society. He received the INFORMS Franz Edelman Award twice: in 2013 for his research on optimal flood protection, and in 2021 for his research on optimizing the food supply chain for the UN World Food Programme. He has been Visiting Professor at MIT for several years now. He is Science-to-Impact Director of the Analytics for a Better World Institute, that he co-founded in 2022.

MERL Host:

Arvind Raghunathan

Research Areas:

Data Analytics, Optimization