Research

Agent-Based Modeling of Co-circulating Viral Strains

Synopsis: concurrently developing compartmental ODE-based and agent-based models for co-circulation of two viral strains and comparison analysis from the model-user standpoint. PI: Thomas Hurd (1956–2022), Michael C. Wolfson (uOttawa).

Related publications:

• Mathematical Models: Perspectives of Mathematical Modelers and Public Health Professionals

Kneading-based Exploration of Lorenz-like Systems

Synopsis: uncovering previously unobserved features within the chaotic regions of the parameter space of the high-dimensional Lorenz systems with connections to atmospheric predictability. In collaboration with Roberto Barrio and Sergio Serrano (U. Zaragoza, Spain).

Atmospheric Predictability and Chaos

Synopsis: Investigating the relationship between atmosphere’s chaotic nature and its predictability with a particular focus on the effects of changing a model’s spatial resolution or numerical precision. Partial funding through NRF Korea Postdoctoral Training Grant (NRF-2021R1A6A3A01086440).

Related publications:

• Increasing model vertical resolution may not necessarily lead to improved atmospheric predictability
• Using the (3N)-Dimensional Generalized Lorenz Systems as a Testbed for Data Assimilation: The Ensemble Kalman Filter
• High-dimensional generalizations of the Lorenz system and implications for predictability

Chaos and Synchronization in High-Order Lorenz Models

Synopsis: rigorous derivation and analysis of high-dimensional extensions of the Lorenz system with additional physically-relevant features, focusing on bifurcation and chaos synchronization. PhD Project. Partial funding through the Small Grant for Exploratory Research (SGER), National Research Foundation of Korea (NRF-2018R1D1A1A02086007); PI: Jong-Jin Baik (Seoul National U.).

Related publications:

• Systematic comparison between the generalized Lorenz equations and DNS in the two-dimensional Rayleigh–Bénard convection
• Coexisting Attractors in a Physically Extended Lorenz System
• Effects of density-affecting scalar on the onset of chaos in a simplified model of thermal convection: a nonlinear dynamical perspective
• Chaos synchronization in generalized Lorenz systems and an application to image encryption
• High-dimensional generalizations of the Lorenz system and implications for predictability
• A physically extended Lorenz system
• Periodicity and Chaos of High-Order Lorenz Systems

Effects of Pandemic-induced Restrictions on Air Quality

Synopsis: analysis of air quality fluctuations during the period under strict social distancing in South Korea based on data collected by air quality monitoring stations. PI: Jong-Jin Baik (Seoul National U.).

Related publications:

• Inter-and intra-city comparisons of PM 2.5 concentration changes under COVID-19 social distancing in seven major cities of South Korea
• Air Quality Change in Seoul, South Korea under COVID-19 Social Distancing: Focusing on PM2.5

Other Atmospheric Science Collaborations

• Orographic–convective flows, wave reflection, and gravity-wave momentum fluxes in a two-layer hydrostatic atmosphere
• Non-Monotonic Dependencies of Cloud Microphysics and Precipitation on Aerosol Loading in Deep Convective Clouds: A Case Study Using the WRF Model with Bin Microphysics
• How Mountain Geometry Affects Aerosol-Cloud-Precipitation Interactions: Part I. Shallow Convective Clouds
• Characteristics of raindrop size distribution in Seoul, South Korea according to rain and weather types
• Effects of Lake Baikal on summertime precipitation climatology over the lake surface

Mathematical Modeling in Epidemiology

Synopsis: developing a computational epidemiological model in the presence of risk-taking vs. risk-averse populations with and without the learning-based behavioral changes during a hypothetical infectious disease epidemic. Undergraduate honors project. Partial funding through the URECA Center, Wake Forest University. co-PIs: Frederick Chen and Miaohua Jiang (Wake Forest U.).