Former members of HYKE visited SNU.

Prof. Qinghua Xiao, Prof. Xiongtao Zhang and Dr. Dongnam Ko visited for new joint work.

There will be an invited talk.

Title: **Green’s functions and Well-posedness of Compressible Navier-Stokes equation**

Speaker: **Prof. Shih-Hsien Yu** (National University of Singapore)

Time: **2018 November 13th, 4:00pm~5:00pm**

Place: **27-220**

Abstract:

A class of decomposition of Green’s functions for the compressilbe Navier-Stokes linearized around a constant state is introduced. The singular structures of the Green’s functions are developed as essential devices to use the nonlinearity directly to covert the 2nd order quasi-linear PDE into a system of zero-th order integral equation with regular integral kernels. The system of integrable equations allows a wider class of functions such as BV solutions. We have shown global existence and well-posedness of the compressible Navier-Stokes equation for isentropic gas with the gas constant γ∈(0,e) in the Lagrangian coordinate for the class of the BV functions and point wise L∞ around a constant state; and the

underline pointwise structure of the solutions is constructed. It is also shown that for the class of BV solution the solution is at most piecewise C2-solution even though the initial data is piecewise C^infty.

There will be an invited talk.

Title: **Vlasov-Poisson-Boltzmann system in convex domains**

Speaker: **Prof. Chanwoo Kim** (Univ. of Wisconsin-Madison)

Time: **2018 November 5th, 11:00am~12:00pm**

Place: **27-220**

Abstract:

We discuss global well-posedness of Vlasov-Poisson-Boltzmann system when the diffuse reflection boundary condition is imposed.

There will be an invited talk.

Title: **Self-Organized Hydrodynamic models for nematic alignment and the application to myxobacteria**

Speaker: **Prof. Hui Yu** (Tsinghua University)

Time: **2018 November 1st, 11:00am~11:50am**

Place: **27-220**

Abstract:

A continuum model for a population of self-propelled particles interacting through nematic alignment is derived from an individual-based model. The methodology consists of introducing a hydrodynamic scaling of the corresponding mean field kinetic equation. The resulting perturbation problem is solved thanks to the concept of generalized collision invariants. It yields a hyperbolic but nonconservative system of equations for the nematic mean direction of the flow and the densities of particles flowing parallel or antiparallel to this mean direction. An application to myxobacteria is presented.

The following is the information for our weekly seminar in this semester.

Date : September 28th, 2018 ~ (every Friday)

Time: 09:00 ~ 12:00

Place: 27-116

Text: “Deep Learning” by Ian Goodfellow, Yoshua Bengio and Aaron Courville

Schedule for presentations

Chapter 4. Woojoo Shim

Chapter 5. Doheon Kim, Dohyun Kim

Chapter 6. Hansol Park

Chapter 7. Jaeseung Lee, Yinglong Zhang

Chapter 8. Weiyuan Zou

Chapter 9. Bora Moon, Jeongho Kim

Chapter 10. Jinwook Jung

If you want to join our seminar, please contact Woojoo Shim: cosmo.shim@gmail.com

The graduation ceremony for people who graduate this semester was held on June 8th, 2018.

Although official graduation ceremony was scheduled to be August, 2018, we held our own ceremony earlier due to other team members’ schedule.

Our team members, Jaeseung Lee and Chanho Min received Ph.D degree, and Inyoung Sung received Master’s degree.

The following is the information about our weekly seminar for the rest of this semester.

Date : May 8th, 2018 ~ (every Tuesday)

Time: 09:00 ~ 11:00

Place: 27-325

Text: “Linear Models in Statistics” by Alvin C. Rencher and G. Bruce Schaalje

If you want to join our seminar, please contact Woojoo Shim. cosmo.shim [at] gmail [dot] com