In this seminar, we will talk about the chemotaxis model, which is a diffusion model for biological dispersion. Chemotaxis is the movement of biological organisms in response to chemical stimuli. The chemotaxis model has nonlinear diffusion with no reaction term and has been extensively studied in the sense of a diffusion model for heterogeneous media. The nonlinear diffusion alone makes it possible to allow us to observe various spatial patterns. We will see what kind of pattern formation the model provides and what mathematical problems this model can be applied to. Language : Korean but English if it is requested

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Discipline of talk: Analysis / Advisor: 김용정 (Yongjung Kim )

In this seminar, I will provide an overview of diffusion generative models, inverse problems, and their applications in solving such problems. Furthermore, I will present a novel interpretation of diffusion generative models and their translation to inverse problems. In collaboration with Hyungjin Chung and Dohoon Ryu, we propose that when data lies in a low-dimensional structure, the set of data with intermediate noise represents the interpolating manifold between the data manifold and the hypersphere of pure noise. Our new method, which respects this geometry, outperforms previous methods, and we provide experimental results as proof of concept.

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Discipline of talk: Applied math, deep learning / Advisor: 예종철 (Jong Chul Ye)

For complex number $\alpha$, let $ A = \begin{bmatrix} 1 & 1 \\ 0 & 1 \end{bmatrix}$ and $B = \begin{bmatrix} 1 & 0 \\ \alpha & 1 \end{bmatrix} $ be two parabolic matrices and let $G_\alpha$ be the group generated by these two matrices. Determining whether $G_\alpha$ is the free group rank 2 or not, is one of the important problems. In this talk, I will introduce a geometric aspect of the group $G_\alpha$ and give previous results of the problem. Next, I will introduce my work joint with KyeongRo Kim.

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Discipline of talk: Geometric Group Theory / Advisor: 백형렬 교수님