Tuesday, August 20, 2024

2024-08-21 / 15:00 ~ 17:00

학과 세미나/콜로퀴엄 - 산업응용수학 세미나: 웨트로폴리스 홍수 예측에서의 극한 환경 이벤트와 극한 파도 역학

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An introduction and overview will be given of extreme events in Wetropolis flood investigator and of extreme water-wave motion in a novel wave-energy device. I will give an overview of the mathematical models and simulations of the phenomena seen in the following movies as well as related phenomena. Subsequently, mathematical and numerical aspects of the novel wave-energy device will be highlighted. As well as a discussion on the Wetropolis World proposal. The related movies which explain Wetropolis: Wetropolis-II (temp link) 2024: https://www.youtube.com/watch?v=g8znktYpxvY, Wetropolis-I 2022: https://www.youtube.com/watch?v=rNgEqWdafKk, The wave-energy device was motived by the bore-soliton-splash (2010): https://www.youtube.com/watch?v=YSXsXNX4zW0&list=FL6mc7mUa6M4Bo2VkD970urw, as well as a first proof of principle (2013): https://www.youtube.com/watch?v=SZhe_SOxBWo

2024-08-27 / 16:30 ~ 17:30

IBS-KAIST 세미나 - 이산수학: Monadic second-order definability for gain-graphic matroids

by Dillon Mayhew(University of Leeds)

Every (finite) matroid consists of a (finite) set called the ground set, and a collection of distinguished subsets called the independent sets. A classic example arises when the ground set is a finite set of vectors from a vector space, and the independent subsets are exactly the subsets that are linearly independent. Any such matroid is said to be representable. We can think of a representable matroid as being a geometrical configuration where the points have been given coordinates from a field. Another important class arises when the points are given coordinates from a group. Such a class is said to be gain-graphic. Monadic second-order logic is a natural language for matroid applications. In this language we are able to quantify only over subsets of the ground set. The importance of monadic second-order logic comes from its connections to the theory of computation, as exemplified by Courcelle’s Theorem. This theorem provides polynomial-time algorithms for recognising properties defined in monadic second-order logic (as long as we impose a bound on the structural complexity of the input objects). It is natural to ask which classes of matroids can be defined by sentences in monadic second-order logic. When the class consists of the matroids that are coordinatized by a field we have a complete answer to this question. When the class is coordinatized by a group the problem becomes much harder. This talk will contain a brief introduction to matroids. Based on work with Sapir Ben-Shahar, Matt Conder, Daryl Funk, Angus Matthews, Mike Newman, and Gabriel Verret.

2024-08-21 / 16:00 ~ 17:00

학과 세미나/콜로퀴엄 - 확률론:

by 성기훈()

In the first part of the talk, I will discuss the asymptotic expansions of the Euclidean Φ^4-measure in the low-temperature regime. Consequently, we derive limit theorems, specifically the law of large numbers and the central limit theorem for the Φ^4-measure in the low-temperature limit. In the second part of the talk, I will focus on the infinite volume limit of the focusing Φ^4-measure. Specifically, with appropriate scaling, the focusing Φ^4-measure exhibits Gaussian fluctuations around a scaled solitary wave, that is, the central limit theorem. This talk is based on joint works with Benjamin Gess, Pavlos Tsatsoulis, and Philippe Sosoe.

2024-08-21 / 16:00 ~ 18:00

학과 세미나/콜로퀴엄 - 위상수학 세미나:

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In this talk, I will talk about isotopy problems of Seifert surfaces pushed in to the 4-ball. In particular, I will prove that every Seifert surface of a non-split alternating link become isotopic in the 4-ball. This is a joint work with Maggie Miller and Jaehoon Yoo.

Events for the 취소된 행사 포함