Blar i Department of Informatics på forfatter "Fomin, Fedor"

Viser treff 21-40 av 62

    • FPT Approximation for Fair Minimum-Load Clustering 

      Bandyapadhyay, Sayan; Fomin, Fedor; Golovach, Petr; Purohit, Nidhi; Simonov, Kirill (Journal article; Peer reviewed, 2022)
      In this paper, we consider the Minimum-Load k-Clustering/Facility Location (MLkC) problem where we are given a set P of n points in a metric space that we have to cluster and an integer k > 0 that denotes the number of ...

    • Going Far from Degeneracy 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Journal article; Peer reviewed, 2020)
      An undirected graph $G$ is $d$-degenerate if every subgraph of $G$ has a vertex of degree at most $d$. By the classical theorem of Erdös and Gallai from 1959, every graph of degeneracy $d>1$ contains a cycle of length at ...

    • Going Far From Degeneracy 

      Fomin, Fedor; Golovach, Petr; Lokshtanov, Daniel; Panolan, Fahad; Saurabh, Saket; Zehavi, Meirav (Peer reviewed; Journal article, 2019-09-06)
      An undirected graph G is d-degenerate if every subgraph of G has a vertex of degree at most d. By the classical theorem of Erd\H{o}s and Gallai from 1959, every graph of degeneracy d>1 contains a cycle of length at least ...

    • How to find a good explanation for clustering? 

      Bandyapadhyay, Sayan; Fomin, Fedor; Golovach, Petr; Lochet, William Alexandre; Purohit, Nidhi; Simonov, Kirill (Journal article; Peer reviewed, 2023)
      k-means and k-median clustering are powerful unsupervised machine learning techniques. However, due to complicated dependencies on all the features, it is challenging to interpret the resulting cluster assignments. Moshkovitz, ...

    • Kernel(s) for Problems with No Kernel: On Out-Trees with Many Leaves 

      Fernau, Henning; Fomin, Fedor; Lokshtanov, Daniel; Raible, Daniel; Saurabh, Saket; Villanger, Yngve (Peer reviewed; Journal article, 2009)
      The {\sc \(k\)-Leaf Out-Branching} problem is to find an out-branching, that is a rooted oriented spanning tree, with at least \(k\) leaves in a given digraph. The problem has recently received much attention from the ...

    • Kernelization of Graph Hamiltonicity: Proper H-Graphs 

      Chaplick, Steven; Fomin, Fedor; Golovach, Petr; Knop, Dusan; Zeman, Peter (Journal article; Peer reviewed, 2021)
      We obtain new polynomial kernels and compression algorithms for Path Cover and Cycle Cover, the well-known generalizations of the classical Hamiltonian Path and Hamiltonian Cycle problems. Our choice of parameterization ...

    • Kernelization of Whitney Switches 

      Fomin, Fedor; Golovach, Petr (Journal article; Peer reviewed, 2020)
      A fundamental theorem of Whitney from 1933 asserts that 2-connected graphs G and H are 2-isomorphic, or equivalently, their cycle matroids are isomorphic, if and only if G can be transformed into H by a series of operations ...

    • Kernelization of Whitney Switches 

      Fomin, Fedor; Golovach, Petr (Journal article; Peer reviewed, 2021)
      A fundamental theorem of Whitney from 1933 asserts that 2-connected graphs $G$ and $H$ are 2-isomorphic, or equivalently, their cycle matroids are isomorphic if and only if $G$ can be transformed into $H$ by a series of ...

    • Largest chordal and interval subgraphs faster than 2n 

      Bliznets, Ivan; Fomin, Fedor; Pilipczuk, Michal Pawel; Villanger, Yngve (Peer reviewed; Journal article, 2015-08-22)
      We prove that in a graph with n vertices, induced chordal and interval subgraphs with the maximum number of vertices can be found in time O(2λn) for some λ< 1. These are the first algorithms breaking the trivial 2nnO(1) ...

    • Long Cycles in Graphs: Extremal Combinatorics Meets Parameterized Algorithms 

      Fomin, Fedor; Golovach, Petr; Sagunov, Danil; Simonov, Kirill (Journal article; Peer reviewed, 2022)
      We discuss recent algorithmic extensions of two classic results of extremal combinatorics about long paths in graphs. First, the theorem of Dirac from 1952 asserts that a 2-connected graph G with the minimum vertex degree ...

    • Longest Cycle Above Erdös-Gallai Bound 

      Fomin, Fedor; Golovach, Petr; Sagunov, Danil; Simonov, Kirill (Journal article; Peer reviewed, 2022)
      In 1959, Erdős and Gallai proved that every graph G with average vertex degree ad(G) ≥ 2 contains a cycle of length at least ad(G). We provide an algorithm that for k ≥ 0 in time 2^𝒪(k)⋅n^𝒪(1) decides whether a 2-connected ...

    • Lossy Kernelization of Same-Size Clustering 

      Bandyapadhyay, Sayan; Fomin, Fedor; Golovach, Petr; Purohit, Nidhi; Simonov, Kirill (Journal article; Peer reviewed, 2023)
      In this work, we study the k-median clustering problem with an additional equal-size constraint on the clusters from the perspective of parameterized preprocessing. Our main result is the first lossy (2-approximate) ...

    • Low-Rank Binary Matrix Approximation in Column-Sum Norm 

      Fomin, Fedor; Golovach, Petr; Panolan, Fahad; Simonov, Kirill (Journal article; Peer reviewed, 2020)
      We consider 𝓁₁-Rank-r Approximation over {GF}(2), where for a binary m× n matrix 𝐀 and a positive integer constant r, one seeks a binary matrix 𝐁 of rank at most r, minimizing the column-sum norm ‖ 𝐀 -𝐁‖₁. We show ...

    • Minimum Fill-in of Sparse Graphs: Kernelization and Approximation 

      Fomin, Fedor; Geevarghese, Philip; Villanger, Yngve (Peer reviewed; Journal article, 2011)
      The Minimum Fill-in problem is to decide if a graph can be triangulated by adding at most k edges. The problem has important applications in numerical algebra, in particular in sparse matrix computations. We develop ...

    • Modification to planarity is fixed parameter tractable 

      Fomin, Fedor; Golovach, Petr; Thilikos, Dimitrios M (Peer reviewed; Journal article, 2019)
      A replacement action is a function L that maps each k-vertex labeled graph to another k-vertex graph. We consider a general family of graph modification problems, called L-Replacement to C, where the input is a graph G and ...

    • A Note on Exact Algorithms for Vertex Ordering Problems on Graphs 

      Bodlaender, Hans L.; Fomin, Fedor; Koster, Arie M.C.A.; Kratsch, Dieter; Thilikos, Dimitrios M. (Peer reviewed; Journal article, 2011-01-21)
      In this note, we give a proof that several vertex ordering problems can be solved in O ∗(2 n ) time and O ∗(2 n ) space, or in O ∗(4 n ) time and polynomial space. The algorithms generalize algorithms for the Travelling ...

    • On the Complexity of Recovering Incidence Matrices 

      Fomin, Fedor; Golovach, Petr; Misra, Pranabendu; Ramanujan, M.S. (Journal article; Peer reviewed, 2020)
      The incidence matrix of a graph is a fundamental object naturally appearing in many applications, involving graphs such as social networks, communication networks, or transportation networks. Often, the data collected about ...

    • On the Parameterized Complexity of the Expected Coverage Problem 

      Fomin, Fedor; Ramamoorthi, Vijayaragunathan (Journal article; Peer reviewed, 2022)
      The MAXIMUM COVERING LOCATION PROBLEM (MCLP) is a well-studied problem in the field of operations research. Given a network with positive or negative demands on the nodes, a positive integer k, the MCLP seeks to find k ...

    • On the Tractability of Optimization Problems on H-Graphs 

      Fomin, Fedor; Golovach, Petr; Raymond, Jean-Florent (Journal article; Peer reviewed, 2020)
      For a graph H, a graph G is an H-graph if it is an intersection graph of connected subgraphs of some subdivision of H. H-graphs naturally generalize several important graph classes like interval graphs or circular-arc ...

    • On width measures and topological problems on semi-complete digraphs 

      Fomin, Fedor; Pilipczuk, Michal (Peer reviewed; Journal article, 2019)
      The topological theory for semi-complete digraphs, pioneered by Chudnovsky, Fradkin, Kim, Scott, and Seymour [10], [11], [12], [28], [43], [39], concentrates on the interplay between the most important width measures — ...