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We consider the probability that a spanning tree chosen uniformly at random from a graph can be partitioned into a fixed number $k$ of trees of equal size by removing $k-1$ edges. In that case, the spanning tree is called {\em splittable}.…

Data Structures and Algorithms · Computer Science 2026-02-25 David Gillman , Jacob Platnick , Dana Randall

We present extraction of tree structures, such as airways, from image data as a graph refinement task. To this end, we propose a graph auto-encoder model that uses an encoder based on graph neural networks (GNNs) to learn embeddings from…

Computer Vision and Pattern Recognition · Computer Science 2018-04-13 Raghavendra Selvan , Thomas Kipf , Max Welling , Jesper H. Pedersen , Jens Petersen , Marleen de Bruijne

We count invertible Schr\"odinger operators (perturbations by diagonal matrices of the adjacency matrix) over finite fieldsfor trees, cycles and complete graphs.This is achieved for trees through the definition and use of local invariants…

Combinatorics · Mathematics 2015-12-22 Roland Bacher

This article focuses on a combinatorial structure specific to triangulated plane graphs with quadrangular outer face and no separating triangle, which are called irreducible triangulations. The structure has been introduced by Xin He under…

Combinatorics · Mathematics 2008-02-07 Eric Fusy

A generic rectangulation is a partition of a rectangle into finitely many interior-disjoint rectangles, such that no four rectangles meet in a point. In this work we present a versatile algorithmic framework for exhaustively generating a…

Combinatorics · Mathematics 2021-11-02 Arturo Merino , Torsten Mütze

Rooted triples, rooted binary phylogenetic trees on three leaves, are sufficient to encode rooted binary phylogenetic trees. That is, if $\mathcal T$ and $\mathcal T'$ are rooted binary phylogenetic $X$-trees that infers the same set of…

Combinatorics · Mathematics 2020-12-07 Charles Semple , Gerry Toft

We present time-efficient distributed algorithms for decomposing graphs with large edge or vertex connectivity into multiple spanning or dominating trees, respectively. As their primary applications, these decompositions allow us to achieve…

Data Structures and Algorithms · Computer Science 2013-11-22 Keren Censor-Hillel , Mohsen Ghaffari , Fabian Kuhn

Surface crack segmentation poses a challenging computer vision task as background, shape, colour and size of cracks vary. In this work we propose optimized deep encoder-decoder methods consisting of a combination of techniques which yield…

Computer Vision and Pattern Recognition · Computer Science 2021-08-27 Jacob König , Mark Jenkins , Mike Mannion , Peter Barrie , Gordon Morison

We present an efficient algorithm to compute permanents, mixed discriminants and hyperdeterminants of structured matrices and multidimensional arrays (tensors). We describe the sparsity structure of an array in terms of a graph, and we…

Discrete Mathematics · Computer Science 2016-04-05 Diego Cifuentes , Pablo A. Parrilo

The \emph{Steiner tree} problem is one of the fundamental and classical problems in combinatorial optimization. In this paper, we study this problem in the $\mathcal{CONGESTED}$ $\mathcal{CLIQUE}$ model of distributed computing and present…

Distributed, Parallel, and Cluster Computing · Computer Science 2019-07-31 Parikshit Saikia , Sushanta Karmakar

The success of deep neural networks in many real-world applications is leading to new challenges in building more efficient architectures. One effective way of making networks more efficient is neural network compression. We provide an…

Machine Learning · Computer Science 2019-12-23 Andrey Kuzmin , Markus Nagel , Saurabh Pitre , Sandeep Pendyam , Tijmen Blankevoort , Max Welling

An SPQR-tree is a data structure that efficiently represents all planar embeddings of a biconnected planar graph. It is a key tool in a number of constrained planarity testing algorithms, which seek a planar embedding of a graph subject to…

Data Structures and Algorithms · Computer Science 2020-09-28 Guido Brückner , Ignaz Rutter

The supertree construction problem is about combining several phylogenetic trees with possibly conflicting information into a single tree that has all the leaves of the source trees as its leaves and the relationships between the leaves are…

Computational Engineering, Finance, and Science · Computer Science 2020-02-19 Laura Koponen , Emilia Oikarinen , Tomi Janhunen , Laura Säilä

If a sparse semidefinite program (SDP), specified over $n\times n$ matrices and subject to $m$ linear constraints, has an aggregate sparsity graph $G$ with small treewidth, then chordal conversion will sometimes allow an interior-point…

Optimization and Control · Mathematics 2024-09-23 Richard Y. Zhang

A triangulation of a surface is irreducible if there is no edge whose contraction produces another triangulation of the surface. In this work we propose an algorithm that constructs the set of irreducible triangulations of any surface with…

We show that the problem of constructing tree-structured descriptions of data layouts that are optimal with respect to space or other criteria from given sequences of displacements, can be solved in polynomial time. The problem is relevant…

Data Structures and Algorithms · Computer Science 2015-07-01 Robert Ganian , Martin Kalany , Stefan Szeider , Jesper Larsson Träff

Gray codes for vector spaces are considered in two graphs: the Grassmann graph, and the projective-space graph, both of which have recently found applications in network coding. For the Grassmann graph, constructions of cyclic optimal codes…

Information Theory · Computer Science 2013-06-12 Moshe Schwartz

We present a procedure to sample uniformly from the set of combinatorial isomorphism types of balanced triangulations of surfaces - also known as graph-encoded surfaces. For a given number $n$, the sample is a weighted set of graph-encoded…

Combinatorics · Mathematics 2022-11-16 Rajan Shankar , Jonathan Spreer

Machine learning on trees has been mostly focused on trees as input to algorithms. Much less research has investigated trees as output, which has many applications, such as molecule optimization for drug discovery, or hint generation for…

Machine Learning · Computer Science 2022-02-11 Benjamin Paassen , Irena Koprinska , Kalina Yacef

A tree decomposition of a graph facilitates computations by grouping vertices into bags that are interconnected in an acyclic structure, hence their importance in a plethora of problems such as query evaluation over databases and inference…

Data Structures and Algorithms · Computer Science 2018-10-09 Noam Ravid , Dori Medini , Benny Kimelfeld