Agent-based models (ABM) play a prominent role in guiding critical decision-making and supporting the development of effective policies for better urban resilience and response to the COVID-19 pandemic. However, many ABMs lack realistic representations of human mobility, a key process that leads to physical interaction and subsequent spread of disease. Therefore, we propose the application of Latent Dirichlet Allocation (LDA), a topic modeling technique, to foot-traffic data to develop a realistic model of human mobility in an ABM that simulates the spread of COVID-19. In our novel approach, LDA treats POIs as “words” and agent home census block groups (CBGs) as “documents” to extract “topics” of POIs that frequently appear together in CBG visits. These topics allow us to simulate agent mobility based on the LDA topic distribution of their home CBG. We compare the LDA based mobility model with competitor approaches including a naive mobility model that assumes visits to POIs are random. We find that the naive mobility model is unable to facilitate the spread of COVID-19 at all. Using the LDA informed mobility model, we simulate the spread of COVID-19 and test the effect of changes to the number of topics, various parameters, and public health interventions. By examining the simulated number of cases over time, we find that the number of topics does indeed impact disease spread dynamics, but only in terms of the outbreak's timing. Further analysis of simulation results is needed to better understand the impact of topics on simulated COVID-19 spread. This study contributes to strengthening human mobility representations in ABMs of disease spread.Three promising high school students, John Pesavento, Andy Chen, and Rayan Yu, presented our recent research "Data-Driven Mobility Models for COVID-19 Simulation" at the 3rd ACM SIGSPATIAL Workshop on Advances in Resilient and Intelligent Cities (ARIC 2020)! I am a witness to their hard work during Aspiring Scientists Summer Internship Program (ASSIP). These dilligent students were mentored by Dr. Andreas Züfle and Dr. Hamdi Kavak and co-mentored by Dr. Anderson Taylor and myself. The presentation at ARIC 2020 was very clear. Well done!
You can check out interactive heatmaps and more information in John Peasavento's GitHub Page. This research is supported by National Science Foundation and by the Aspiring Scientists Summer Internship Program (ASSIP) at George Mason University.