Results 11  20
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199
Geometric Clustering: FixedParameter Tractability and Lower Bounds with Respect to the Dimension
"... We present an algorithm for the 3center problem in (Rd, L1), i. e., for finding the smallest side length for 3 cubes that cover a given npoint set in Rd, that runs in O(n log n) time for any fixed dimension d. This shows that the problem is fixedparameter tractable when parameterized with d. On ..."
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Cited by 7 (6 self)
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We present an algorithm for the 3center problem in (Rd, L1), i. e., for finding the smallest side length for 3 cubes that cover a given npoint set in Rd, that runs in O(n log n) time for any fixed dimension d. This shows that the problem is fixedparameter tractable when parameterized with d
On FixedParameter Tractability of Some Routing Problems (Extended Version)
, 2002
"... Disjoint Paths is the problem of finding paths between given pairs of terminals in a graph such that no vertices are shared between paths. We analyze fixedparameter tractability of several new Disjoint Pathslike routing problems motivated by congestion control in computer networks. ..."
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Disjoint Paths is the problem of finding paths between given pairs of terminals in a graph such that no vertices are shared between paths. We analyze fixedparameter tractability of several new Disjoint Pathslike routing problems motivated by congestion control in computer networks.
Drawing binary tanglegrams: Hardness, approximation, fixedparameter tractability
"... A binary tanglegram is a pair 〈S, T〉 of binary trees whose leaf sets are in onetoone correspondence; matching leaves are connected by intertree edges. For applications, for example in phylogenetics, it is essential that both trees are drawn with no edge crossing and that the intertree edges hav ..."
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Cited by 1 (1 self)
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have as few crossings as possible. It is known that finding a drawing with the minimum number of crossings is NPhard and that the problem is fixedparameter tractable with respect to that number. We show that the problem is hard even if both trees are complete binary trees. For this case we give an O
Fixedparameter tractability of the maximum agreement supertree problem (Extended Abstract)
, 2007
"... Given a ground set L of labels and a collection of trees whose leaves are bijectively labelled by some elements of L, the Maximum Agreement Supertree problem (SMAST) is the following: find a tree T on a largest label set L′ ⊆ L that homeomorphically contains every input tree restricted to L′. The p ..."
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Cited by 3 (0 self)
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′. The problem finds applications in several fields, e.g. phylogenetics. In this paper we focus on the parameterized complexity of this NPhard problem. We consider different combinations of parameters for SMAST as well as particular cases, providing both FPT algorithms and intractability results.
A FixedParameter Tractable Algorithm for SpatioTemporal Calendar Management
"... Calendar management tools assist users with coordinating their daily life. Different tasks have to be scheduled according to the user preferences. In many cases, tasks are at different locations and travel times have to be considered. Therefore, these kinds of calendar management problems can be reg ..."
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is a fixedparameter tractable algorithm that depends on the maximal number of tasks that can be revisited from some other task, a parameter which is small in the application scenario we consider. 1
Imbalance is Fixed Parameter Tractable
"... Abstract. In the Imbalance Minimization problem we are given a graph G = (V, E) and an integer b and asked whether there is an ordering v1... vn of V such that the sum of the imbalance of all the vertices is at most b. The imbalance of a vertex vi is the absolute value of the difference between the ..."
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Cited by 1 (1 self)
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the number of neighbors to the left and right of vi. The problem is also known as the Balanced Vertex Ordering problem and it finds many applications in graph drawing. We show that this problem is fixed parameter tractable and provide an algorithm that runs in time 2 O(b log b) · n O(1). This resolves
A FixedParameter Algorithm for Minimum Quatet Inconsistency
 Journal of Computer and System Sciences
, 2003
"... Given n taxa, exactly one topology for every subset of four taxa, and a positive integer k (the parameter), the Minimum Quartet Inconsistency (MQI) problem is the question whether we can find an evolutionary tree inducing a set of quartet topologies that di#ers from the given set in only k quarte ..."
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Cited by 18 (2 self)
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quartet topologies. The more general problem where we are not necessarily given a topology for every subset of four taxa appears to be fixedparameter intractable. For MQI, however, which is also NPcomplete, we can compute the required tree in time O(4 ). This means that the problem is fixedparameter
Distortion is Fixed Parameter Tractable
"... We study lowdistortion embedding of metric spaces into the line, and more generally, into the shortest path metric of trees, from the parameterized complexity perspective. Let M = M(G) be the shortest path metric of an edge weighted graph G, with the vertex set V (G) and the edge set E(G), on n v ..."
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Cited by 3 (2 self)
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improvement over the best previous algorithm of Bădoiu et al. that runs in time O(n 4d+2 d O(1)). Because of its apparent similarity to the notoriously hard Bandwidth Minimization problem, we find it surprising that this problem turns out to be fixed parameter tractable. We extend our results on embedding
IEEE/ACM TRANSACTIONS ON COMPUTATIONAL BIOLOGY AND BIOINFORMATICS 1 FixedParameter Tractability of the Maximum Agreement Supertree Problem
"... Abstract — Given a set L of labels and a collection of rooted trees whose leaves are bijectively labelled by some elements of L, the Maximum Agreement Supertree problem (SMAST) is as follows: find a tree T on a largest label set L ′ ⊆ L that homeomorphically contains every input tree restricted to L ..."
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. This shows that SMAST can be solved efficiently when the input trees are mostly congruent. Then for the particular case where any triple of leaves is contained in at least one input tree, we give O(4 p n 3) and O(3.12 p + n 4) time algorithms, obtaining the first fixedparameter tractable algorithms on a
Approximation and FixedParameter Algorithms for Consecutive Ones Submatrix Problems
 JOURNAL OF COMPUTER AND SYSTEM SCIENCES
"... We develop an algorithmically useful refinement of a forbidden submatrix characterization of 0/1matrices fulfilling the Consecutive Ones Property (C1P). This characterization finds applications in new polynomialtime approximation algorithms and fixedparameter tractability results for the NPhard ..."
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Cited by 12 (0 self)
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We develop an algorithmically useful refinement of a forbidden submatrix characterization of 0/1matrices fulfilling the Consecutive Ones Property (C1P). This characterization finds applications in new polynomialtime approximation algorithms and fixedparameter tractability results for the NP
Results 11  20
of
199