Browsing by Author "Serna Iglesias, María José"
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A Characterization of universal stability for directed graphs in the adversarial queueing model
Álvarez Faura, M. del Carme; Blesa Aguilera, Maria Josep; Serna Iglesias, María José (200201)
Research report
Open AccessIn this paper we provide a characterization of universal stability for digraphs in the general case that the packets are not restricted to follow simple paths. Furthermore, we consider a variation of the Nearest To Go ... 
A Characterization of universal stability in the adversarial queuing model
Serna Iglesias, María José; Blesa Aguilera, Maria Josep; Álvarez Faura, M. del Carme (200310)
Research report
Open AccessWe study universal stability of directed and undirected graphs in the adversarial queueing model for static packet routing. In this setting, packets are injected in some edge and have to traverse a predefined path before ... 
A Constructive linear time algorithm for small cutwidth
Thilikos Touloupas, Dimitrios; Serna Iglesias, María José; Bodlaender, Hans L. (200009)
Research report
Open AccessThe cutwidth of a graph G is defined to be the smallest integer k such that the vertices of G can be arranged in a linear layout [v(1),...,v(n)] in such a way that for every i=1,...,n1, there are at most k edges with the ... 
A costbenefit analysis of continuous assessment
Duch Brown, Amalia; Gabarró Vallès, Joaquim; Petit Silvestre, Jordi; Blesa Aguilera, Maria Josep; Serna Iglesias, María José (SciTePress, 2015)
Conference report
Open AccessThe first course on programming is fundamental in the Facultat d’Informàtica de Barcelona. After a major redesign of the Programming1 course in 2006 to give it a more practical flavor, an increasing number of measures ... 
A list of parameterized problems in bioinformatics
Félix Ávila, Liliana; García Chacón, Alina; Serna Iglesias, María José; Thilikos Touloupas, Dimitrios (200605)
Research report
Open AccessIn this report we present a list of problems that originated in bionformatics. Our aim is to collect information on such problems that have been analyzed from the point of view of Parameterized Complexity. For every problem ... 
A Polynomial time algorithm for the cutwidth of bounded degree graphs with small treewidth
Thilikos Touloupas, Dimitrios; Serna Iglesias, María José; Bodlaender, Hans L. (200102)
Research report
Open AccessThe cutwidth of a graph G is defined to be the smallest integer k such that the vertices of G can be arranged in a vertex ordering [v(1),...,v(n)] in a way that, for every i=1,...,n1, there are at most k ... 
A Random graph model for optical networks of sensors
Díaz Cort, Josep; Petit Silvestre, Jordi; Serna Iglesias, María José (200212)
Research report
Open AccessIn this paper we propose a model for Smart Dust Networks and show its applicability when the goal of the network is monitoring an area under the surveillance of a base station. We analyze basic parameters of these nets and ... 
A Survey on graph layout problems
Díaz Cort, Josep; Petit Silvestre, Jordi; Serna Iglesias, María José (200010)
Research report
Open AccessIn this paper we survey results on several graph layout problems from an algorithmic point of view. Graph layout problems are a particular class of combinatorial optimization problems whose goal is to find a linear layout ... 
Absorption time of the Moran process
Díaz Cort, Josep; Goldberg, Leslie Ann; Richerby, David; Serna Iglesias, María José (20160801)
Article
Open Access© 2016 Wiley Periodicals, Inc. The Moran process models the spread of mutations in populations on graphs. We investigate the absorption time of the process, which is the time taken for a mutation introduced at a randomly ... 
Adversarial models for prioritybased networks
Álvarez Faura, M. del Carme; Díaz Cort, Josep; Blesa Aguilera, Maria Josep; Fernández Anta, Antonio; Serna Iglesias, María José (200306)
Research report
Open AccessWe propose several variations of the adversarial queueing model. The priority model takes into account the case in which the packets can have different priorities, assigned by the adversary at injection time. The ... 
Adversarial queueing model for continuous network dynamics
Blesa Aguilera, Maria Josep; Calzada, Daniel; Fernández Anta, Antonio; López, Luís; Martínez Fernández, Andrés; Santos, Agustín; Serna Iglesias, María José (200505)
Research report
Open AccessIn this paper we start the study of generalizing the Adversarial Queueing Theory (AQT) model towards a continuous scenario in which the usually assumed synchronicity of the evolution is not required anymore. We consider a ... 
Algorítmica per a paral·lelisme massiu : introducció
Díaz Cort, Josep; Serna Iglesias, María José (Edicions UPC, 1999)
Book
Restricted access to the UPC academic communityAquest llibre és una introducció al disseny d’algorismes paral·lels per a màquines síncrones. Als capítols 15 es presenten els conceptes bàsics del disseny d’algorismes per a xarxes d’interconexió: vectors, meshes, meshes ... 
An angeldaemon approach to assess the uncertainty in the power of a collectivity to act
Fragnito, Giulia; Gabarró Vallès, Joaquim; Serna Iglesias, María José (Springer, 2017)
Conference report
Open AccessWe propose the use of the angeldaemon framework to assess the Coleman's power of a collectivity to act under uncertainty in weighted voting games. In this framework uncertainty profiles describe the potential changes ... 
Analysing weborchestrations under stress using uncertainty profiles
Gabarró Vallès, Joaquim; Serna Iglesias, María José; Stewart, Alan (Wiley Heyden, 20141101)
Article
Open AccessAn orchestration is a multithreaded computation that invokes a number of remote services. In practice, the responsiveness of a webservice fluctuates with demand; during surges in activity service responsiveness may be ... 
Análisis de la evolución de un curso: productividad y desigualdad
Blesa Aguilera, Maria Josep; Duch Brown, Amalia; Gabarró Vallès, Joaquim; Petit Silvestre, Jordi; Serna Iglesias, María José (Universidad de Almería, 20160705)
Conference lecture
Open AccessEste trabajo analiza cuantitativamente las diferentes medidas adoptadas en la evaluación contínua del curso de Programación1 de la Facultat d’Informàtica de Barcelona de la Universitat Politècnica de Catalunya desde 2010, ... 
Approximating convex quadratic programming is Pcomplete
Serna Iglesias, María José; Xhafa Xhafa, Fatos (1995)
Research report
Open AccessIn this paper we show that the problem of Approximating Convex Quadratic Programming is Pcomplete. We also consider two approximation problems related to it, Solution Approximation and Value Approximation and show both ... 
Approximating layout problems on geometric random graphs
Díaz Cort, Josep; Penrose, Mathew D.; Petit Silvestre, Jordi; Serna Iglesias, María José (19981013)
Research report
Open AccessWe show two simple algorithms that, with high probability, approximate within a constant several layout problems for geometric random graphs drawn from the Gn(r) model r_cv(log¿¿n/n¿ ) for any constant c = 6. The layout ... 
Approximating layout problems on random sparse graphs
Díaz Cort, Josep; Petit Silvestre, Jordi; Serna Iglesias, María José; Trevisan, Marco (199807)
Research report
Open AccessWe show that, with high probability, several layout problems are approximable within a constant for random graphs drawn from the standard Gnp model with p=c/n for some constant c. Our results establish that, in fact, ... 
Approximating scheduling problems in parallel
Serna Iglesias, María José; Xhafa Xhafa, Fatos (199704)
Research report
Open AccessWe show how to approximate in NC the problem of Scheduling Unrelated Parallel Machines, for a fixed number of machines. We develop a (2+epsilon)approximate parallel algorithm for the problem. Our approach shows how to ... 
Approximating the permanent is in RNC
Díaz Cort, Josep; Serna Iglesias, María José; Spirakis, Paul George (199504)
Research report
Open AccessIn this work we look into the parallelization (in the NC sense) of the Markov Chain approach to almost random generation, as described by Sinclair (1993). We give a RNC almost uniform generator for perfect matchings in ...