O-joung Kwon (권오정), Classes of intersection digraphs with good algorithmic properties
An intersection digraph is a digraph where every vertex $v$ is represented by an ordered pair $(S_v, T_v)$ of sets such that there is an edge from $v$ to $w$ …
10 events found.
Discrete Math Seminar
Events
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Zoom ID: 875 9395 3555 (relay) [CLOSED]
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Hongseok Yang (양홍석), DAG-symmetries and Symmetry-Preserving Neural Networks
Room B232 IBS (기초과학연구원)The preservation of symmetry is one of the key tools for designing data-efficient neural networks. A representative example is convolutional neural networks (CNNs); they preserve translation symmetries, and this symmetry …
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Jeong Ok Choi (최정옥), Invertibility of circulant matrices of arbitrary size
Room B232 IBS (기초과학연구원)In this talk, we present sufficient conditions to guarantee the invertibility of rational circulant matrices with any given size. These sufficient conditions consist of linear combinations in terms of the …
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Suil O (오수일), Eigenvalues and [a, b]-factors in regular graphs
Room B232 IBS (기초과학연구원)For positive integers, $r \ge 3, h \ge 1,$ and $k \ge 1$, Bollobás, Saito, and Wormald proved some sufficient conditions for an $h$-edge-connected $r$-regular graph to have a k-factor …
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Jaehoon Kim (김재훈), $K_{r+1}$-saturated graphs with small spectral radius
Room B232 IBS (기초과학연구원)For a graph $H$, a graph $G$ is $H$-saturated if $G$ does not contain $H$ as a subgraph but for any $e\in E(\overline G)$, $G+e$ contains $H$. In this note, we prove …
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Semin Yoo (유세민), Combinatorics of Euclidean spaces over finite fields
Room B232 IBS (기초과학연구원)$q$-analogues of quantities in mathematics involve perturbations of classical quantities using the parameter $q$, and revert to the original quantities when $q$ goes $1$. An important example is the $q$-analogues …
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Euiwoong Lee (이의웅), The Karger-Stein algorithm is optimal for k-cut
Room B232 IBS (기초과학연구원)In the k-cut problem, we are given an edge-weighted graph and want to find the least-weight set of edges whose deletion breaks the graph into k connected components. It is …
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Duksang Lee (이덕상), Intertwining connectivities for vertex-minors and pivot-minors
Room B232 IBS (기초과학연구원)We show that for pairs (Q,R) and (S,T) of disjoint subsets of vertices of a graph G, if G is sufficiently large, then there exists a vertex v in V(G)−(Q∪R∪S∪T) such …
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Linda Cook, Two results on graphs with holes of restricted lengths
Room B232 IBS (기초과학연구원)We call an induced cycle of length at least four a hole. The parity of a hole is the parity of its length. Forbidding holes of certain types in a graph …
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Eun Jung Kim (김은정), A Constant-factor Approximation for Weighted Bond Cover
Room B232 IBS (기초과학연구원)The Weighted $\mathcal F$-Vertex Deletion for a class $\mathcal F$ of graphs asks, given a weighted graph $G$, for a minimum weight vertex set $S$ such that $G-S\in\mathcal F$. The …