Now showing items 1-20 of 44

    • 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 (2002-01)
      Research report
      Open Access
      In 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 (2003-10)
      Research report
      Open Access
      We 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 Compendium of problems complete for symmetric logarithmic space 

      Álvarez Faura, M. del Carme; Greenlaw, Raymond (1996-06)
      Research report
      Open Access
      We provide a compendium of problems that are complete for symmetric logarithmic space. Complete problems are one method ofstudying this class for which programming is nonintuitive. A number ofthe problems in the list were ...
    • A note on log space optimization 

      Álvarez Faura, M. del Carme; Jenner, Birgit (1992-12-30)
      Research report
      Open Access
      We show that computing iterated multiplication of word matrices over {0,1}, using the operations maximum and concatenation, is complete for the class optL of log space optimization functions. The same problem for word ...
    • Adaptive logspace reducibility and parallel time 

      Álvarez Faura, M. del Carme; Balcázar Navarro, José Luis; Jenner, Birgit (1991-11)
      Research report
      Open Access
      We discuss two notions of functional oracle for logarithmic space-bounded machines, which differ in whether there is only one oracle tape for both the query and the answer or a separate tape for the answer, which can still ...
    • Adversarial models for priority-based networks 

      Álvarez Faura, M. del Carme; Díaz Cort, Josep; Blesa Aguilera, Maria Josep; Fernández Anta, Antonio; Serna Iglesias, María José (2003-06)
      Research report
      Open Access
      We 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 ...
    • CALCULABILITAT (Examen 2n quadrim) 

      Álvarez Faura, M. del Carme (Universitat Politècnica de Catalunya, 2009-05-25)
      Exam
      Restricted access to the UPC academic community
    • Celebrity games 

      Álvarez Faura, M. del Carme; Blesa Aguilera, Maria Josep; Duch Brown, Amalia; Messegué Buisan, Arnau; Serna Iglesias, María José (2016-10-04)
      Article
      Open Access
      We introduce Celebrity games, a new model of network creation games. In this model players have weights (W being the sum of all the player's weights) and there is a critical distance ß as well as a link cost a. The cost ...
    • Communication tree problems 

      Álvarez Faura, M. del Carme; Cases Muñoz, Rafel; Díaz Cort, Josep; Petit Silvestre, Jordi; Serna Iglesias, María José (2001-03)
      Research report
      Open Access
      In this paper, we consider random communication requirements and several cost measures for a particular model of tree routing on a complete network. First we show that a random tree does not give any approximation. Then ...
    • Continuous monitoring in the dynamic sensor field model 

      Álvarez Faura, M. del Carme; Díaz Cort, Josep; Dieter Wilhelm, Mitsche; Serna Iglesias, María José (2011-05)
      Research report
      Open Access
      In this work we consider the problem of continuously monitoring a collection of data sets produced by sensors placed on moving or static targets. We propose a modification of the static sensor field model (SSSF) [2] to ...
    • Els Límits de la computació : indecidibilitat i NP-completesa 

      Serna Iglesias, María José; Álvarez Faura, M. del Carme; Cases Muñoz, Rafel; Lozano Boixadors, Antoni (Edicions UPC, 2001)
      Book
      Restricted access to the UPC academic community
      Aquest text presenta una introducció a les teories de la calculabilitat i la complexitat a l'abast d'un estudiant de primer cicle d'una enginyeria informàtica. A partir de la justificació de la necessitat d'un model formal ...
    • Firefighting as a Game 

      Álvarez Faura, M. del Carme; Blesa Aguilera, Maria Josep; Molter, Hendrik (2014)
      Research report
      Open Access
      The Firefighter Problem was proposed in 1995 [16] as a deterministic discrete-time model for the spread (and containment) of a fire. Its applications reach from real fires to the spreading of deseases and the containment ...
    • Firefighting as a game 

      Álvarez Faura, M. del Carme; Blesa Aguilera, Maria Josep; Molter, Hendrik (2014-12-10)
      Article
      Open Access
      The Firefighter Problem was proposed in 1995 [16] as a deterministic discrete-time model for the spread (and containment) of a fire. Its applications reach from real fires to the spreading of diseases and the containment ...
    • Firefighting as a strategic game 

      Álvarez Faura, M. del Carme; Blesa Aguilera, Maria Josep; Molter, Hendrik (Taylor & Francis, 2016-03-31)
      Article
      Open Access
      The Firefighter Problem was proposed in 1995 as a deterministic discrete-time model for the spread and containment of a fire. The problem is defined on an undirected finite graph G = (V, E), where fire breaks out initially ...
    • Funcions booleanes: caracterització dels nivells de la jerarquia booleana 

      Álvarez Faura, M. del Carme (1987-11)
      Research report
      Open Access
      We study two hierarchies defined beetwen NP and ¿p2: The K-Boolean Hierarchy, when K=NP, (Wechsung, Wagner (1985)), and the Boolean Hierarchy (Cai, Hemachandra (1986)). Every level of these two hierarchies is caracterized ...
    • Functional oracle queries as a measure of parallel time 

      Álvarez Faura, M. del Carme; Balcázar Navarro, José Luis; Jenner Núñez, Birgit (1990-08)
      Research report
      Open Access
      We discuss two notions of functional oracle for logarithmic space-bounded machines, which differ in whether there is only one oracle tape for both the query and the answer or a separate tape for the answer, which can still ...
    • High level communication functionalities for wireless sensor networks 

      Álvarez Faura, M. del Carme; Díaz Cort, Josep; Petit Silvestre, Jordi; Rolim, José; Serna Iglesias, María José (2004-11)
      Research report
      Open Access
      In this work we propose a way to establish a reliable and efficient high level communication system in a randomly deployed network of sensors equipped with directional antennas. This high level communication system will ...
    • Intervalizing colored graphs is NP-complete for caterpilars with hair length 2 

      Álvarez Faura, M. del Carme; Díaz Cort, Josep; Serna Iglesias, María José (1998-02)
      Research report
      Open Access
      The problem of Intervalizing Colored Graphs has received a lot of attention due to their use as a model for DNA physical mapping with ambiguous data. If k is the number of colors, the problem is known to be NP-Complete ...
    • Logarithmic space counting classes 

      Álvarez Faura, M. del Carme; Jenner Núñez, Birgit (1990-01)
      Research report
      Open Access
      We consider the logarithmic space counting classes #L, opt-L, and span-L, which are defined analogously to their polynomial time counterparts. We obtain complete functions for these three classes in terms of graphs and ...
    • Maria Serna in Barcelona 

      Álvarez Faura, M. del Carme (Elsevier, 2021-02)
      Article
      Restricted access - publisher's policy
      Here we present a collection of short notes, written by some Maria’s colleagues and friends, describing how we see her. The aim of this compilation is to express our respect and admiration and congratulate you, Maria, in ...