Date of Award

Fall 2024

Degree Type

Restricted to Claremont Colleges Dissertation

Degree Name

Mathematics, PhD

Program

Institute of Mathematical Sciences

Advisor/Supervisor/Committee Chair

Yan Li & Allon Percus

Dissertation or Thesis Committee Member

Marina Chugunova

Terms of Use & License Information

Creative Commons Attribution 4.0 License
This work is licensed under a Creative Commons Attribution 4.0 License.

Rights Information

© 2024 Zhengming Song

Keywords

Deep Learning, Graph Neural Networks, Neural Network, Spatiotemporal Forecasting, Time Series Forecastin, Traffic Speed Prediction

Subject Categories

Mathematics

Abstract

Accurately forecasting complex, multivariate time series varying across space and time requires models that effectively capture spatial and temporal dependencies inherent in the data. This dissertation introduces a novel architecture based on Graph Neural Networks that addresses the challenges of time series prediction, while also providing unique insights through decomposition of model outputs in the spatio-temporal space. We apply our method to the problem of traffic speed prediction, using benchmark datasets that we curate from Caltrans Performance Measurement System data. These datasets include detailed traffic speed and flow information across hundreds of sensors in four geographic districts in California, as well as spatial configurations like road networks, Euclidean distances, and temporal graphs. We present comparisons of our model with existing methods from the literature. We investigate how different graph structures and the inclusion of external factors, such as auxiliary data, influence the model's predictive performance. Our findings reveal that temporal information plays a critical role in improving accuracy, while spatial features yield mixed results depending on regional characteristics. Incorporating external factors such as traffic flow data generally enhances our model's performance, with the degree of improvement varying based on context and model configuration. Finally, we propose guidance to practitioners on interpreting the results from the model output decomposition.

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