Results 61 to 70 of about 143,400 (232)

Topological Symmetry Groups of Complete Bipartite Graphs [PDF]

, 2015
The symmetries of complex molecular structures can be modeled by the {\em topological symmetry group} of the underlying embedded graph. It is therefore important to understand which topological symmetry groups can be realized by particular abstract ...
Hake, Kathleen, Mellor, Blake, Pittluck, Matthew   +2 more
core   +2 more sources

PAIR: Reconstructing Single‐Cell Open‐Chromatin Landscapes for Transcription Factor Regulome Mapping

Advanced Science, EarlyView.
scATAC‐seq analysis is often constrained by limited sequencing depth, extreme sparsity, and pervasive technical missingness. PAIR is a probabilistic framework that restores scATAC‐seq accessibility profiles by directly modeling the native cell–peak bipartite structure of chromatin accessibility.
Yanchi Su, Qi Qi, Yi Fan, Yubo Wang, Gaoyang Hao, Ka‐Chun Wong, Yunhe Wang, Xiangtao Li   +7 more
wiley   +1 more source

Large subgraphs without complete bipartite graphs [PDF]

, 2014
In this note, we answer the following question of Foucaud, Krivelevich and Perarnau. What is the size of the largest $K_{r,s}$-free subgraph one can guarantee in every graph $G$ with $m$ edges?
Conlon, David, Fox, Jacob, Sudakov, Benny   +2 more
core   +2 more sources

Restricted Tweedie stochastic block models

Canadian Journal of Statistics, EarlyView.
Abstract The stochastic block model (SBM) is a widely used framework for community detection in networks, where the network structure is typically represented by an adjacency matrix. However, conventional SBMs are not directly applicable to an adjacency matrix that consists of nonnegative zero‐inflated continuous edge weights.
Jie Jian, Mu Zhu, Peijun Sang
wiley   +1 more source

Star Bicolouring of Bipartite Graphs

Algorithms
We give an integer linear program formulation for the star bicolouring of bipartite graphs. We develop a column generation method to solve the linear programming relaxation to obtain a lower bound for the minimum number of colours needed.
Daya Gaur, Shahadat Hossain, Rishi Ranjan Singh   +2 more
doaj   +1 more source

Minimum Degree up to Local Complementation: Bounds, Parameterized Complexity, and Exact Algorithms

, 2015
The local minimum degree of a graph is the minimum degree that can be reached by means of local complementation. For any n, there exist graphs of order n which have a local minimum degree at least 0.189n, or at least 0.110n when restricted to bipartite ...
A Bouchet, A Bouchet, B Zeng, D Cattanéo, D Cattanéo, D Markham, DG Fon-Der-Flaasss, H Fraysseix de, J Javelle, M Hein, M Nest Van den, M Plotkin, P Høyer, R Raussendorf, RG Downey, S Beigi, S Gravier, S Gravier, S Oum   +18 more
core   +3 more sources

Intersection Numbers of the Natural Embedding of the Twisted Triality Hexagon T ( q 3 , q ) ${\mathsf{T}}({q}^{3},q)$ in PG ( 7 , q 3 ) ${\mathsf{PG}}(7,{q}^{3})$

Journal of Combinatorial Designs, EarlyView.
ABSTRACT In this paper, we study and characterise the natural embedding of the twisted triality hexagon T ( q 3 , q ) ${\mathsf{T}}({q}^{3},q)$ in PG ( 7 , q 3 ) ${\mathsf{PG}}(7,{q}^{3})$. We begin by describing the possible intersections of subspaces of PG ( 7 , q 3 ) ${\mathsf{PG}}(7,{q}^{3})$ with T ( q 3 , q ) ${\mathsf{T}}({q}^{3},q)$.
Sebastian Petit, Geertrui Van de Voorde
wiley   +1 more source

Complexity of Roman {2}-domination and the double Roman domination in graphs

AKCE International Journal of Graphs and Combinatorics, 2020
For a simple, undirected graph a Roman {2}-dominating function (R2DF) has the property that for every vertex with f(v) = 0, either there exists a vertex with f(u) = 2, or at least two vertices with The weight of an R2DF is the sum The minimum weight of ...
Chakradhar Padamutham, Venkata Subba Reddy Palagiri   +1 more
doaj   +1 more source

Transforming Solutions for the Oberwolfach Problem into Solutions for the Spouse‐Loving Variant

Journal of Combinatorial Designs, EarlyView.
ABSTRACT The Oberwolfach problem OP ( F ) $\mathrm{OP}(F)$, for a 2‐factor F $F$ of K n ${K}_{n}$, asks whether there exists a 2‐factorization of K n ${K}_{n}$ (if n $n$ is odd) or K n − I ${K}_{n}-I$ (if n $n$ is even) where each 2‐factor is isomorphic to F $F$. Here, I $I$ denotes any 1‐factor of K n ${K}_{n}$. For even n $n$, the problem OP( F ) $(F)
Maruša Lekše, Mateja Šajna
wiley   +1 more source

Partitioning Perfect Graphs into Stars

, 2016
The partition of graphs into "nice" subgraphs is a central algorithmic problem with strong ties to matching theory. We study the partitioning of undirected graphs into same-size stars, a problem known to be NP-complete even for the case of stars on three
Bredereck, Robert, Bulteau, Laurent, Chen, Jiehua, Froese, Vincent, Niedermeier, Rolf, van Bevern, René, Woeginger, Gerhard J.   +6 more
core   +3 more sources