Browsing Departament de Tecnologies de la Informació i les Comunicacions by Issue Date

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Browsing Departament de Tecnologies de la Informació i les Comunicacions by Issue Date

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  • Lozano Solsona, Àngel (Institute of Electrical and Electronics Engineers (IEEE), 2003)
    The simultaneous use of multiple transmit and receive antennas can unleash very large capacity increases in rich multipath environments. Although such capacities can be approached by layered multi-antenna architectures ...
  • Bote-Lorenzo, Miguel L.; Hernández Leo, Davinia; Dimitriadis, Yannis; Asensio-Pérez, Juan I.; Gómez-Sánchez, Eduardo; Vega-Gorgojo, Guillermo; Vaquero-Gónzalez, Luis M. (ACTA Press, 2004)
    CSCL applications are complex distributed systems that pose special requirements towards achieving success in educational settings. Flexible and efficient design of collaborative activities by educators is a key ...
  • Hernández Leo, Davinia; Asensio-Pérez, Juan I.; Dimitriadis, Yannis; Bote-Lorenzo, Miguel L.; Jorrín-Abellán, Iván M.; Villasclaras-Fernández, Eloy D. (ACTA Press, 2005)
    Designs of CSCL (Computer Supported Collaborative Learning) activities should be flexible, effective and customizable to particular learning situations. On the other hand, structured designs aim to create favourable ...
  • Tulino, Antonia M.; Lozano Solsona, Àngel; Verdú, Sergio (Institute of Electrical and Electronics Engineers (IEEE), 2005)
    This paper applies random matrix theory to obtain analytical characterizations of the capacity of correlated multiantenna channels. The analysis is not restricted to the popular separable correlation model, but rather it ...
  • Bonet, Blai; Geffner, Hector (Association for the Advancement of Artificial Intelligence (AAAI), 2005)
    We describe the version of the GPT planner to be used in the planning competition. This version, called mGPT, solves mdps specified in the ppddl language by extracting and using different classes of lower bounds, along ...
  • Hernández Leo, Davinia; Asensio-Pérez, Juan I.; Dimitriadis, Yannis (International Forum of Educational Technology & Society, 2005)
    The identification and integration of reusable and customizable CSCL (Computer Supported Collaborative Learning) may benefit from the capture of best practices in collaborative learning structuring. The authors have proposed ...
  • Lozano Solsona, Àngel; Tulino, Antonia M.; Verdú, Sergio (Institute of Electrical and Electronics Engineers (IEEE), 2006)
    The mutual information of independent parallel Gaussian-noise channels is maximized, under an average power constraint, by independent Gaussian inputs whose power is allocated according to the waterfilling policy. In ...
  • Tulino, Antonia M.; Lozano Solsona, Àngel; Verdú, Sergio (Institute of Electrical and Electronics Engineers (IEEE), 2006)
    We characterize the capacity-achieving input covariance for multi-antenna channels known instantaneously at the receiver and in distribution at the transmitter. Our characterization, valid for arbitrary numbers of antennas, ...
  • Lozano Solsona, Àngel; Tulino, Antonia M.; Verdú, Sergio (Institute of Electrical and Electronics Engineers (IEEE), 2006)
    The analysis of the multiantenna capacity in the high-SNR regime has hitherto focused on the high-SNR slope (or maximum multiplexing gain), which quantifies the multiplicative increase as function of the number of antennas. ...
  • Jorrín-Abellán, Iván M.; Ruiz-Requies, Inés; Hernández Leo, Davinia; Villasclaras-Fernández, Eloy D.; Dimitriadis, Yannis; Rubia-Avi, Bartolomé; Asensio-Pérez, Juan I. (International Forum of Educational Technology & Society, 2006)
    This paper introduces Collage, a high-level IMS-LD compliant authoring tool that is specialized for CSCL (Computer-Supported Collaborative Learning). Nowadays CSCL is a key trend in elearning since it highlights the ...
  • Igual, Laura; Preciozzi, Javier; Garrido, Luís; Almansa, Andrés; Caselles, Vicent; Rougé, Bernard (AIMS American Institute of Mathematical Sciences, 2007)
    In this work we propose a new automatic methodology for computing accurate digital elevation models (DEMs) in urban environments from low baseline stereo pairs that shall be available in the future from a new kind of earth ...
  • Hernández Leo, Davinia; Bote-Lorenzo, Miguel L.; Asensio-Pérez, Juan I.; Gómez-Sánchez, Eduardo; Villasclaras-Fernández, Eloy D.; Jorrín-Abellán, Iván M.; Dimitriadis, Yannis (Institute of Electrical and Electronics Engineers (IEEE), 2007)
    This paper describes a Computer-Supported Collaborative Learning (CSCL) case study in engineering education carried out within the context of a network management course. The case study shows that the use of two computing ...
  • Deco, Gustavo; Scarano, Leandro; Soto Faraco, Salvador (Society for Neuroscience, 2007)
    Recent single-cell studies in monkeys (Romo et al., 2004) show that the activity of neurons in the ventral premotor cortex covaries with the animal's decisions in a perceptual comparison task regarding the frequency of ...
  • Faridi, Azadeh; Ephremides, Anthony (Institute of Electrical and Electronics Engineers (IEEE), 2008)
    We investigate the problem of finding minimum-distortion policies for streaming delay-sensitive but distortion-tolerant data. We consider cross-layer approaches which exploit the coupling between presentation and transport ...
  • Cramer, Ronald; Daza, Vanesa; Gracia, Ignacio; Jiménez Urroz, Jorge; Leander, Gregor; Martí-Farré, Jaume; Padró, Carles (Institute of Electrical and Electronics Engineers (IEEE), 2008)
    Error-correcting codes and matroids have been widely used in the study of ordinary secret sharing schemes. In this paper, the connections between codes, matroids, and a special class of secret sharing schemes, namely, ...
  • Daza, Vanesa; Herranz, Javier; Sáez, Germán (Institute of Electrical and Electronics Engineers (IEEE), 2008)
    In a distributed key distribution scheme, a set of servers helps a set of users in a group to securely obtain a common key. Security means that an adversary who corrupts some servers and some users has no information about ...
  • Biglieri, Ezio (National Institute of Information and Communications Technology (NICT), 2008)
    We examine a multiple-access communication system in which multiuser detection is performed without knowledge of the number of active interferers. Using a statistical-physics approach, we compute the single-user channel ...
  • Angelosante, Daniele; Biglieri, Ezio; Lops, Marco (European Association for Signal Processing (EURASIP), 2008)
    This paper presents several algorithms for joint estimation of the target number and state in a time-varying scenario. Building on the results presented in [1], which considers estimation of the target number only, we ...
  • Angelosante, Daniele; Biglieri, Ezio; Lops, Marco (European Association for Signal Processing (EURASIP), 2008)
    In multiuser detection, the set of users active at any time may be unknown to the receiver. In these conditions, optimum reception consists of detecting simultaneously the set of active users and their data, problem that ...
  • Biglieri, Ezio; Hong, Yi; Viterbo, Emanuele (European Association for Signal Processing (EURASIP), 2008)
    Silver Code (SilC) was originally discovered in [1–4] for 2×2 multiple-input multiple-output (MIMO) transmission. It has non-vanishing minimum determinant 1/7, slightly lower than Golden code, but is fast-decodable, i.e., ...

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