Ara es mostren els items 7-22 de 22

    • Free form surfaces 

      Cotrina Navau, Josep; Pla García, Núria (2000-05)
      Report de recerca
      Accés obert
      A method to construct continuous order k surfaces of arbitrary topological type by tracing a mesh that represents a 2-manifold is presented. The presented approach constructs the surface from a collection of pieces which ...
    • IEEE 802.11g performance in presence of beacon control frames 

      López Aguilera, M. Elena; Casademont Serra, Jordi; Cotrina Navau, Josep (Institute of Electrical and Electronics Engineers, 2004-09)
      Text en actes de congrés
      Accés obert
      Most studies of the performance of IEEE 802.11 consider scenarios of ad-hoc topology networks and do not contemplate the network broadcast information contained in beacon frames. The paper presents a study of the performance ...
    • Informàtica bàsica II, ETSEIB. Memòria del curs 1994-1995 

      Vila Marta, Sebastià; Pla García, Núria; Soto Riera, Antoni; Pérez Vidal, Lluís; Roura Ferret, Salvador; Franquesa Niubó, Marta; Cotrina Navau, Josep; Alquézar Mancho, René; Martínez Parra, Conrado (1995-02-06)
      Report de recerca
      Accés obert
      Memòria de l'assignatura d'Infomàtica bàsica II del curs 94-95.
    • Modelling surfaces from planar irregular meshes 

      Cotrina Navau, Josep; Pla García, Núria (1998-06)
      Report de recerca
      Accés obert
      We present a method for constructing surfaces from irregular control meshes that can be embedded in the plane. This method results from a generalization of B-Splines using the known technology of manifolds. The resulting ...
    • Multisided patches 

      Pla García, Núria; Vigo Anglada, Marc; Cotrina Navau, Josep (2004-06)
      Report de recerca
      Accés obert
      We present a method to construct a patch of parametric surface of degree k + 1 that lls a n-sided hole, with n bigger than 2, and whose boundary coincides with a B-Spline, thus, the resulting patch can be easily connected ...
    • N-sided patches with B-spline boundaries 

      Cotrina Navau, Josep; Pla García, Núria; Vigo Anglada, Marc (2001-12)
      Report de recerca
      Accés obert
      We present a method to construct a patch of parametric surface of degree k+1 that fills a n-sided hole, with bigger than 2, and whose boundary coincides with a B-Spline, thus, the resulting patch can be easily connected ...
    • Outdoor IEEE 802.11g cellular network performance 

      López Aguilera, M. Elena; Casademont Serra, Jordi; Cotrina Navau, Josep (Institute of Electrical and Electronics Engineers, 2004)
      Text en actes de congrés
      Accés obert
      Most studies about the performance of IEEE 802.11 are limited to a single cell environment. Nevertheless, the idea of designing an outdoor cellular network based on WLAN IEEE 802.11 is very attractive, due to the several ...
    • Performance enhancement of outdoor IEEE 802.11 cellular networks 

      López Aguilera, M. Elena; Casademont Serra, Jordi; Rojas Espinosa, Alfonso; Cotrina Navau, Josep (ACTA Press, 2005-07)
      Text en actes de congrés
      Accés obert
      Most studies about the performance of IEEE 802.11 are limited to a single cell environment. Nevertheless, the idea of designing an outdoor cellular network based on WLAN IEEE 802.11 results very attractive, due to the ...
    • Performance enhancement of WLAN IEEE 802.11 for asymmetric traffic 

      López Aguilera, M. Elena; Casademont Serra, Jordi; Cotrina Navau, Josep; Rojas Espinosa, Alfonso (Institute of Electrical and Electronics Engineers, 2005)
      Text en actes de congrés
      Accés obert
      Most studies about the performance of IEEE 802.11 consider scenarios of ad-hoc topology and networks where all stations have the same traffic load (symmetric traffic conditions). This paper presents a study of performance ...
    • Sobre la justicia en las redes IEEE 802.11e: desincronización de su mecanismo de acceso al medio 

      López Aguilera, M. Elena; Casademont Serra, Jordi; Cotrina Navau, Josep (Institute of Electrical and Electronics Engineers, 2007-10)
      Article
      Accés obert
      Since the advent of the first IEEE 802.11 standard, several papers have proposed means of providing QoS to IEEE 802.11 networks and evaluate various traffic-prioritization mechanisms. Nevertheless, studies on the assignment ...
    • Study of asymmetric traffic influence on IEEE 802.11 WLAN family, enhancement proposals 

      López Aguilera, M. Elena; Casademont Serra, Jordi; Cotrina Navau, Josep (Institute of Electrical and Electronics Engineers, 2004-04)
      Text en actes de congrés
      Accés obert
      This paper is focused on the study of WLAN performance in IEEE 802.11 networks that are in a situation of asymmetric traffic, where the access point (AP) transmits much more than the user stations (US). This situation is ...
    • Surveillance with alert management system using conventional cell phones 

      Gorricho Moreno, Juan Luis; Brezmes, Tomas; Cotrina Navau, Josep; Rersa, Marc (IEEE Computer Society Publications, 2010)
      Text en actes de congrés
      Accés obert
      In the present paper we expose the development of a real-time monitoring prototype of human activities using a single cell phone equipped with some sensors. The monitoring system is reduced to the minimum expression; ...
    • Towards free form surfaces 

      Cotrina Navau, Josep; Pla García, Núria; Vigo Anglada, Marc (2001-03)
      Report de recerca
      Accés obert
      A theoretical approach to construct free form surfaces is presented. We develop the conceps that arise when a free form surface is generated by tracing a mesh, using differentiable manifold theory, and generalizing the ...
    • Tracing traitors by guessing secrets. The q-ary case 

      Fernández Muñoz, Marcel; Soriano Ibáñez, Miguel; Cotrina Navau, Josep (Springer, 2005)
      Text en actes de congrés
      Accés restringit per política de l'editorial
      In this paper we present, by solving a variant of the guessing secrets problem defined by Chung, Graham and Leighton [3], a sequential traitor tracing scheme equipped with an efficient identification algorithm. Sequential ...
    • User activity monitoring using conventional cell phones 

      Brezmes, Tomas; Gorricho Moreno, Juan Luis; Cotrina Navau, Josep; Rersa, Marc (2010-04-09)
      Text en actes de congrés
      Accés obert
      User activity monitoring has a considerable potential for a whole range of new applications in different environments: user surveillance, military purposes, health-care, etc. More precisely, in health-care there is an ...
    • Wireless technology applied to GIS 

      Casademont Serra, Jordi; López Aguilera, M. Elena; Paradells Aspas, Josep; Rojas Espinosa, Alfonso; Calveras Augé, Anna M.; Barceló Arroyo, Francisco; Cotrina Navau, Josep (Elsevier, 2004-07)
      Article
      Accés restringit per política de l'editorial
      At present, there is a growing interest in wireless applications, due to the fact that the technology begins to support them at reasonable costs. In this paper, we present the technology currently available for use in ...