Graduate Students Seminar

Speaker 1: Bo liu

Title

Robust Radiation Source Detection and Localization

Abstract

Autonomous robots are increasingly used for tasks like facility decommissioning and managing nuclear accidents. However, a significant challenge remains in estimating multiple radiation sources over large areas. Mobile radiation detectors struggle to identify radioactive hotspots without prior information about the number or locations of these sources. To address this issue, we developed a particle filter-based approach designed to estimate radiation fields from sparse measurements. Our method integrates sequential multi-layer estimation with a peak suppression technique to effectively manage multimodal particle swarms. By employing multiple swarms and applying specific centroid filtering criteria, the algorithm successfully captures and verifies the non-parametric characteristics related to the number of sources, as shown in our simulations.

Speaker 2: Alex Sheranko

Title

A kernel based SIR model for infectious spread in space and time

Abstract

In this study, we consider a system of ODEs designed to describe the spatial spread of an epidemic. This model builds on the classical SIR model to define infection rates while still producing a diffusive-like spread. A key feature of the model is the flexibility it offers through the selection of different kernels, enabling precise control over the dynamics of disease propagation. Like a generalized elliptic operator, the kernel can generate anisotropic spread and is allowed to vary through space and time. Through simulations, we illustrate various infection spread patterns and explore the qualitative behavior of the model under different scenarios.