| 구분 |
박사학위 논문 심사 |
| 일정 |
2019-10-17(목) 10:00~12:30 |
| 세미나실 |
129동 406호 |
| 강연자 |
김영진 (서울대학교) |
| 담당교수 |
국웅 |
| 기타 |
|
A harmonic cycle λ, also called a discrete harmonic form, is a solution of the Laplace`s equation with the combinatorial Laplace operator obtained from the boundary operators of a simplicial chain complex. By combinatorial Hodge theory, harmonic spaces are isomorphic to homology groups with real coefficients. In particular, if a cell complex has a one dimensional reduced homology, it has a unique harmonic cycle up to scalar multiplication, which we call the standard harmonic cycle.
We will present a formula for the standard harmonic cycle λ of a cell complex based on a high-dimensional generalization of cycletrees. Moreover, by using duality, we will define the standard harmonic cocycle λ* and show intriguing combinatorial properties of λ and λ* in relation to (dual) spanning trees, (dual) cycletrees, winding numbers w( · ) and cutting numbers c( · ) in high dimensions.
Finally, we will also suggest application methods; an analysis to detect oscillations by using winding number, and cutting number, and a network embedding method, called harmonic mirroring.