PhD Thesis Defense: Navid Rashedi
"Data鈥慸riven Dynamic Decision鈥憁aking Using Discrete Optimization and Supervised Machine Learning"
Optional
Meeting ID: 244 072 091 379
Passcode: CF2y3s4S
Abstract: In recent years, the operations research community has developed data鈥慸riven optimization techniques to solve complex combinatorial problems with the aid of machine learning. This thesis contributes to these efforts by combining machine learning with optimization to expedite online decision鈥憁aking, with applications in transportation and healthcare.
In the domain of airline operations recovery, the focus is on the aircraft鈥憆ecovery process—repairing disrupted schedules by minimizing overall disruption costs. Traditional exact methods are too time鈥慶onsuming, while heuristic approaches often yield poor solution quality and lack generalizability across varying formulations. To address these challenges, this research employs supervised machine learning to identify near鈥憃ptimal solution components by leveraging historical data. By integrating binary classification methods into a decision鈥慳ware framework, our approach prunes the decision space effectively, yielding high鈥憅uality solutions in significantly shorter runtimes than both exact and heuristic methods.
In the healthcare domain, for the diagnosis of occult hemorrhage, we develop a data鈥慸riven framework that takes advantage of multisensor data and vital signs to detect internal bleeding early, particularly under capacity constraints. We conduct extensive experiments with animal and human data to engineer high鈥慺idelity features and maximize predictive accuracy. Building on these predictions, we propose a decision鈥慳ware machine learning approach that dynamically updates patient risk scores over time and optimizes admissions to resource鈥慽ntensive care units. Our method balances the trade鈥憃ff between acting early (with less accurate information) versus waiting for more precise data, thus reducing both false positives and missed diagnoses.
Through extensive computational experiments on realistic data sets, this thesis demonstrates that our integrated, decision鈥慳ware framework not only accelerates online decision鈥憁aking but also consistently produces near鈥憃ptimal solutions, offering significant improvements in both airline operations recovery and hemorrhage diagnosis.
Thesis Committee: Prof. Vikrant Vaze (Chair), Prof. Jonathan T. Elliott, Prof. Eugene Santos, Jr., Prof. Alexandre Jacquillat (Massachusetts Institute of Technology)