Exploració per autor "Thilikos Touloupas, Dimitrios"
Ara es mostren els items 26-37 de 37
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New upper bounds on the decomposability of planar graphs and fixed parameter algorithms
Fomin, Fedor V.; Thilikos Touloupas, Dimitrios (2002-08)
Report de recerca
Accés obertIt is known that a planar graph on n vertices has branch-width/tree-width bounded by alphasqrt{n}. In many algorithmic applications it is useful to have a small bound on the constant alpha. We give a ... -
On graph powers for leaf-labeled trees
Nishimura, Naomi; Prabhakar, Ragde; Thilikos Touloupas, Dimitrios (2000-07)
Report de recerca
Accés obertWe extend the well-studied concept of a graph power to that of a k-leaf power G of a tree T: G is formed by creating a node for each leaf in the tree and an edge between a pair of nodes if and only if the associated ... -
On the existence of Nash equilibria in strategic search games
Álvarez Faura, M. del Carme; Duch Brown, Amalia; Serna Iglesias, María José; Thilikos Touloupas, Dimitrios (2011)
Text en actes de congrés
Accés obertWe consider a general multi-agent framework in which a set of n agents are roaming a network where m valuable and sharable goods (resources, services, information ....) are hidden in m different vertices of the network. ... -
On the monotonicity of games generated by symmetric submodular functions
Fomin, Fedor V.; Thilikos Touloupas, Dimitrios (2001-02)
Report de recerca
Accés obertSubmodular functions have appeared to be a key tool for proving the monotonicity of several graph searching games. In this paper we provide a general game theoretic framework able to unify old and new monotonicity ... -
Outerplanar obstructions for the vertex feedback set
Rué Perna, Juan José; Thilikos Touloupas, Dimitrios; Stavropoulos, Konstantinos (2012-07-02)
Article
Accés obertFor k = 1, let Fk be the class of graphs that contains k vertices meeting all its cycles. The minor-obstruction set for Fk is the set obs(Fk) containing all minor-minimal graphs that do not belong to Fk. We denote by Yk ... -
Problems and conjectures on parameterized H-coloring
Díaz Cort, Josep; Serna Iglesias, María José; Thilikos Touloupas, Dimitrios (2002-03)
Report de recerca
Accés obert -
Recent results on parameterized H-coloring
Díaz Cort, Josep; Serna Iglesias, María José; Thilikos Touloupas, Dimitrios (2002-03)
Report de recerca
Accés obertWe survey recent results on the complexity of several versions of the H-coloring and the list-H-coloring problems that are amenable to parameterization. -
Smaller kernels for hitting set problems of constant arity
Nishimura, Naomi; Ragde, Prabhakar; Thilikos Touloupas, Dimitrios (2004-05)
Report de recerca
Accés obertWe demonstrate a kernel of size O(k^2) for 3-HITTING SET when all subsets in the collection to be hit are of size at most three), giving a partial answer to an open question of Niedermeier by improving on the O(k^3) ... -
Structure and enumeration of K4-minor-free links and link diagrams
Rué Perna, Juan José; Thilikos Touloupas, Dimitrios; Velona, Vasiliki (2018-07-01)
Article
Accés obertWe study the class L of link-types that admit a K4-minor-free diagram, i.e., they can be projected on the plane so that the resulting graph does not contain any subdivision of K4. We prove that L is the closure of a subclass ... -
Structure and enumeration of K4-minor-free links and link-diagrams
Rué Perna, Juan José; Thilikos Touloupas, Dimitrios; Velona, Vasiliki (2020-10-01)
Article
Accés obertWe study the class of link-types that admit a -minor-free diagram, i.e., they can be projected on the plane so that the resulting graph does not contain any subdivision of . We prove that is the closure of a subclass of ... -
The Complexity of restrictive H-coloring
Díaz Cort, Josep; Serna Iglesias, María José; Thilikos Touloupas, Dimitrios (2002-03)
Report de recerca
Accés obertWe define a variant of the H-coloring problem where the number of preimages of certain vertices is predetermined as part of the problem input. We consider the decision and the counting version of the problem, namely ... -
The price of connectedness in expansions
Fomin, Fedor V.; Fraigniaud, Pierre; Thilikos Touloupas, Dimitrios (2004-05)
Report de recerca
Accés obertExpansion is the way of generalizing different graph layout and searching problems. We initiate the study of connected expansion which naturally arises in a number of applications. Our main tool for this investigation ...