Browsing Department of Informatics by Title
Now showing items 413432 of 630

Packing arcdisjoint cycles in tournaments
(Journal article; Peer reviewed, 2019)A tournament is a directed graph in which there is a single arc between every pair of distinct vertices. Given a tournament T on n vertices, we explore the classical and parameterized complexity of the problems of determining ... 
Packing cycles faster than ErdosPosa
(Journal article; Peer reviewed, 2019)The Cycle Packing problem asks whether a given undirected graph $G=(V,E)$ contains $k$ vertexdisjoint cycles. Since the publication of the classic ErdösPósa theorem in 1965, this problem received significant attention ... 
Parallel algorithms for computing kconnectivity
(Master thesis, 20170505) 
Parallel algorithms for matching under preference
(Master thesis, 20170620) 
Parallel Graph Algorithms for Combinatorial Scientific Computing
(Doctoral thesis, 20110826) 
Parallel Matching and Clustering Algorithms on GPUs
(Doctoral thesis, 20170617) 
Parameter optimisation for the improved modelling of industrialscale gas explosions
(Doctoral thesis, 20190617)This thesis presents work on improving the predictive capabilities of a numerical model by parameter optimisation. The numerical model is based on computational fluid dynamics (CFD) and predicts the consequences of ... 
Parameterization Above a Multiplicative Guarantee
(Journal article; Peer reviewed, 2020)Parameterization above a guarantee is a successful paradigm in Parameterized Complexity. To the best of our knowledge, all fixedparameter tractable problems in this paradigm share an additive form defined as follows. Given ... 
Parameterized complexity classification of deletion to list matrixpartition for loworder matrices
(Journal article; Peer reviewed, 2019)Given a symmetric l x l matrix M=(m_{i,j}) with entries in {0,1,*}, a graph G and a function L : V(G)  > 2^{[l]} (where [l] = {1,2,...,l}), a list Mpartition of G with respect to L is a partition of V(G) into l parts, ... 
Parameterized complexity of conflictfree matchings and paths
(Journal article; Peer reviewed, 2019)An input to a conflictfree variant of a classical problem Gamma, called ConflictFree Gamma, consists of an instance I of Gamma coupled with a graph H, called the conflict graph. A solution to ConflictFree Gamma in (I,H) ... 
Parameterized Complexity of Directed Spanner Problems
(Journal article; Peer reviewed, 2020)We initiate the parameterized complexity study of minimum tspanner problems on directed graphs. For a positive integer t, a multiplicative tspanner of a (directed) graph G is a spanning subgraph H such that the distance ... 
Parameterized complexity of Eulerian deletion problems
(Peer reviewed; Journal article, 201401)We study a family of problems where the goal is to make a graph Eulerian, i.e., connected and with all the vertices having even degrees, by a minimum number of deletions. We completely classify the parameterized complexity ... 
The Parameterized Complexity of Guarding Almost Convex Polygons
(Journal article; Peer reviewed, 2020)The Art Gallery problem is a fundamental visibility problem in Computational Geometry. The input consists of a simple polygon P, (possibly infinite) sets G and C of points within P, and an integer k; the task is to decide ... 
Parameterized complexity of PCA
(Journal article; Peer reviewed, 2020)We discuss some recent progress in the study of Principal Component Analysis (PCA) from the perspective of Parameterized Complexity. 
Parameterized complexity of secluded connectivity problems
(Conference object; Peer reviewed; Journal article, 2015)The Secluded Path problem introduced by Chechik et al. in [ESA 2013] models a situation where a sensitive information has to be transmitted between a pair of nodes along a path in a network. The measure of the quality of ... 
Parameterized complexity of the spanning tree congestion problem
(Peer reviewed; Journal article, 201209)We study the problem of determining the spanning tree congestion of a graph. We present some sharp contrasts in the parameterized complexity of this problem. First, we show that on apexminorfree graphs, a general class ... 
Parameterized Graph Modification Algorithms
(Doctoral thesis, 20151210)Graph modification problems form an important class of algorithmic problems in computer science. In this thesis, we study edge modification problems towards classes related to chordal graphs, with the main focus on trivially ... 
Parameterized kClustering: Tractability Island
(Peer reviewed; Journal article, 2019)In kClustering we are given a multiset of n vectors X subset Z^d and a nonnegative number D, and we need to decide whether X can be partitioned into k clusters C_1, ..., C_k such that the cost sum_{i=1}^k min_{c_i in R^d} ... 
Parameterized SingleExponential Time Polynomial Space Algorithm for Steiner Tree
(Peer reviewed; Journal article, 2019)In the Steiner Tree problem, we are given as input a connected \(n\)vertex graph with edge weights in \(\{1,2,\ldots,W\}\), and a set of \(k\) terminal vertices. Our task is to compute a minimumweight tree that contains ... 
Parameterized streaming algorithms for minones dSAT
(Journal article; Peer reviewed, 2019)In this work, we initiate the study of the MinOnes dSAT problem in the parameterized streaming model. An instance of the problem consists of a dCNF formula F and an integer k, and the objective is to determine if F has ...