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Related papers: The Mutual-Visibility Problem In Directed Graphs

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In the Maximum Connectivity Improvement (MCI) problem, we are given a directed graph $G=(V,E)$ and an integer $B$ and we are asked to find $B$ new edges to be added to $G$ in order to maximize the number of connected pairs of vertices in…

Discrete Mathematics · Computer Science 2019-04-30 Federico Corò , Gianlorenzo D'Angelo , Vahan Mkrtchyan

Directed acyclic graph (DAG) models, also called Bayesian networks, impose conditional independence constraints on a multivariate probability distribution, and are widely used in probabilistic reasoning, machine learning and causal…

Statistics Theory · Mathematics 2022-12-20 Robin J. Evans

A directed graph G = (V,E) is singly connected if for any two vertices v, u of V, the directed graph G contains at most one simple path from v to u. In this paper, we study different algorithms to find a feasible but necessarily optimal…

Data Structures and Algorithms · Computer Science 2022-11-29 Ahmed Zahloote , Al-hasan Saleh , Ayman Ghanem , Hiba Hasan , Asem Dreibaty , Ali Abodaraa , Nermeen Suleiman , Nour Naameh , Ali Ibrahim , Zeinab mahfoud

Let $G$ be a directed graph such that the in-degree of any vertex $G$ is at least one. Let also ${\mathcal{\tau}}: V(G)\rightarrow \Bbb{N}$ be an assignment of thresholds to the vertices of $G$. A subset $M$ of vertices of $G$ is called a…

Combinatorics · Mathematics 2012-12-18 Kaveh Khoshkhah , Hossein Soltani , Manouchehr Zaker

In causal inference on directed acyclic graphs, the orientation of edges is in general only recovered up to Markov equivalence classes. We study Markov equivalence classes of uniformly random directed acyclic graphs. Using a tower…

Probability · Mathematics 2024-10-01 Dominik Schmid , Allan Sly

This paper considers the problem of estimating the structure of multiple related directed acyclic graph (DAG) models. Building on recent developments in exact estimation of DAGs using integer linear programming (ILP), we present an ILP…

Machine Learning · Statistics 2014-11-13 Chris J. Oates , Jim Q. Smith , Sach Mukherjee , James Cussens

The diameter of an undirected unweighted graph $G=(V,E)$ is the maximum value of the distance from any vertex $u$ to another vertex $v$ for $u,v \in V$ where distance i.e. $d(u,v)$ is the length of the shortest path from $u$ to $v$ in $G$.…

Data Structures and Algorithms · Computer Science 2017-11-13 Bhadrachalam Chitturi , Priyanshu Das

A temporal (directed) graph is a graph whose edges are available only at specific times during its lifetime, $\tau$. Paths are sequences of adjacent edges whose appearing times are either strictly increasing or non-strictly increasingly…

Combinatorics · Mathematics 2023-03-01 Isnard Lopes Costa , Raul Lopes , Andrea Marino , Ana Silva

A directed multigraph is said vulnerable if it can generate Braess paradox in Traffic Networks. In this paper, we give a graph-theoretic characterisation of vulnerable directed multigraphs; analogous results appeared in the literature only…

Data Structures and Algorithms · Computer Science 2024-05-24 Pietro Cenciarelli , Daniele Gorla , Ivano Salvo

The competition graph of a directed acyclic graph D is the undirected graph on the same vertex set as D in which two distinct vertices are adjacent if they have a common out-neighbor in D. The competition number of an undirected graph G is…

Combinatorics · Mathematics 2013-10-24 Brendan D. McKay , Pascal Schweitzer , Patrick Schweitzer

Networks are often modeled using graphs, and within this setting we introduce the notion of $k$-fault-tolerant mutual visibility. Informally, a set of vertices $X \subseteq V(G)$ in a graph $G$ is a $k$-fault-tolerant mutual-visibility set…

Combinatorics · Mathematics 2025-12-02 Serafino Cicerone , Gabriele Di Stefano , Sandi Klavžar , Gang Zhang

We consider the problem of decomposing the edges of a directed graph into as few paths as possible. There is a natural lower bound for the number of paths needed in an edge decomposition of a directed graph $D$ in terms of its degree…

Combinatorics · Mathematics 2021-09-29 Alberto Espuny Díaz , Viresh Patel , Fabian Stroh

We propose a novel score-based approach to learning a directed acyclic graph (DAG) from observational data. We adapt a recently proposed continuous constrained optimization formulation to allow for nonlinear relationships between variables…

Machine Learning · Computer Science 2020-02-19 Sébastien Lachapelle , Philippe Brouillard , Tristan Deleu , Simon Lacoste-Julien

Let $G$ be a connected graph and $\cal X \subseteq V(G)$. By definition, two vertices $u$ and $v$ are $\cal X$-visible in $G$ if there exists a shortest $u,v$-path with all internal vertices being outside of the set $\cal X$. The largest…

Combinatorics · Mathematics 2024-03-26 Gülnaz Boruzanli Ekinci , Csilla Bujtás

In observational studies, the true causal model is typically unknown and needs to be estimated from available observational and limited experimental data. In such cases, the learned causal model is commonly represented as a partially…

Artificial Intelligence · Computer Science 2023-03-01 Malte Luttermann , Marcel Wienöbst , Maciej Liśkiewicz

A polynomial-time exact algorithm for counting the number of directed acyclic graphs in a Markov equivalence class was recently given by Wien\"obst, Bannach, and Li\'skiewicz (AAAI 2021). In this paper, we consider the more general problem…

Data Structures and Algorithms · Computer Science 2023-06-14 Vidya Sagar Sharma

We study unit disk visibility graphs, where the visibility relation between a pair of geometric entities is defined by not only obstacles, but also the distance between them. That is, two entities are not mutually visible if they are too…

Computational Geometry · Computer Science 2021-03-29 Onur Çağırıcı , Deniz Ağaoğlu

The investigation of directed acyclic graphs (DAGs) encoding the same Markov property, that is the same conditional independence relations of multivariate observational distributions, has a long tradition; many algorithms exist for model…

Methodology · Statistics 2012-09-27 Alain Hauser , Peter Bühlmann

Treewidth on undirected graphs is known to have many algorithmic applications. When considering directed width-measures there are much less results on their deployment for algorithmic results. In 2022 the first author, Rabinovich and…

Combinatorics · Mathematics 2024-05-10 Meike Hatzel , Johannes Schröder

We study fundamental directed graph (digraph) problems in the streaming model. An initial investigation by Chakrabarti, Ghosh, McGregor, and Vorotnikova [SODA'20] on streaming digraphs showed that while most of these problems are provably…

Data Structures and Algorithms · Computer Science 2024-05-10 Prantar Ghosh , Sahil Kuchlous
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