Improving wireless multicast communications with NC: performance assessment over a COTS platform

Multicast services are believed to play a relevant role in next wireless networking scenarios. In this paper we exploit Tunable Sparse Network Coding techniques to increase reliability of multicast communications. We show that the proposed network coding scheme yields a better performance than state-of-the-art solutions, which are traditionally based on retransmissions. We first use a model to analytically compare the two approaches. Then, we validate and broaden this analysis by means of an experimental campaign over a testbed deployed with Commercial Of-The-Shelf devices. This platform, comprising low cost devices (Raspberry-PI), allows us to assess the feasibility of the proposed solution, which offers a relevant gain in terms of performance.This work has been supported by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the project ADVICE (TEC2015-71329-C2-1-R)

Uplink power control modeling for dense OFDMA-based heterogeneous networks

In this paper we propose a novel model for the uplink in heterogeneous cellular networks. Opposed to previous works, we accurately account for the mutual interference caused by other users’ connections, and we pose an optimization problem that can be straightforwardly solved to establish the minimum required transmission power that satisfies the minimum Signal-to-Interferenceplus-Noise Ratio (SINR) constraint. We assess the validity of the proposed approach by comparing the observed results with those obtained with a traditional closed-loop power control scheme. The main benefit of our solution is that it does not require any iteration to find the transmission power, while legacy approaches usually need a number of steps before finding it. Finally, we study the behavior of the uplink for different access selection strategies, and we compare the SINR and transmission power of open-loop and closed-loop power control solutions.This work has been supported by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the projects ADVICE: Dynamic provisioning of connectivity in high density 5G wireless scenarios (TEC2015-71329-C2-1-R) and Future Internet Enabled Resilient Cities (FIERCE)

Sparse Intra-Flow Network Coding: comportamiento y modelado

Los autores agradecen la financiación del Gobierno de España (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) de este trabajo a través del proyecto ADVICE, Dynamic provisioning of connectivity in high density 5G wireless scenarios (TEC2015-71329-C2-1-R)

Boussinesq Solitons as Propagators of Neural Signals

We  consider  certain  approximation for determining the  equation  of motion  for nerve  signals by  using  the  model  of the  lipid  melting  of membranes.   The  nerve  pulses  are  found  to  display nonlinearity and  dispersion  during  the  melting  transition.  In this  simplified model the  nonlinear equation  early  proposed  by  Heimburg  and  coworkers  transformed to  the  well known  integrable Boussinesq  non linear  equation.   Under  specific values of the  parametric space this  system  shows the  existence  of singular  and  regular  soliton  like structures.   After  their  collisions  the  mutual creation  and annihilation (each other)  of nerve signals along the  nerve,  during  their  propagation, has been observed.Keywords: Boussinesq equation,  singular  solitons,  single neurons,  neural  code

A Markov chain model for the decoding probability of sparse network coding

Random linear network coding has been shown to offer an efficient communication scheme, leveraging a remarkable robustness against packet losses. However, it suffers from a high-computational complexity, and some novel approaches, which follow the same idea, have been recently proposed. One of such solutions is sparse network coding (SNC), where only few packets are combined with each transmission. The amount of data packets to be combined can be set from a density parameter/distribution, which could be eventually adapted. In this paper, we present a semi-analytical model that captures the performance of SNC on an accurate way. We exploit an absorbing Markov process, where the states are defined by the number of useful packets received by the decoder, i.e., the decoding matrix rank, and the number of non-zero columns at such matrix. The model is validated by the means of a thorough simulation campaign, and the difference between model and simulation is negligible. We also include in the comparison of some more general bounds that have been recently used, showing that their accuracy is rather poor. The proposed model would enable a more precise assessment of the behavior of SNC techniques.This work has been supported by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the projects COSAIF, “Connectivity as a Service: Access for the Internet of the Future” (TEC2012-38754-C02-01), and ADVICE (TEC2015-71329-C2-1-R). This work was also financed in part by the TuneSCode project (No. DFF 1335-00125) granted by the Danish Council for Independent Research

Accurate simulation of 802.11 indoor links: a “bursty” channel model based on real measurements

We propose a novel channelmodel to be used for simulating indoor wireless propagation environments. An extensive measurement campaign was carried out to assess the performance of different transport protocols over 802.11 links. This enabled us to better adjust our approach, which is based on an autoregressive filter. One of the main advantages of this proposal lies in its ability to reflect the “bursty” behavior which characterizes indoor wireless scenarios, having a great impact on the behavior of upper layer protocols.We compare this channel model, integrated within the Network Simulator (ns-2) platform, with other traditional approaches, showing that it is able to better reflect the real behavior which was empirically assessed

Joint scheduling and coding for low in-order delivery delay over lossy paths with delayed feedback

We consider the transmission of packets across a lossy end-to-end network path so as to achieve low in-order delivery delay. This can be formulated as a decision problem, namely deciding whether the next packet to send should be an information packet or a coded packet. Importantly, this decision is made based on delayed feedback from the receiver. While an exact solution to this decision problem is challenging, we exploit ideas from queueing theory to derive scheduling policies based on prediction of a receiver queue length that, while suboptimal, can be efficiently implemented and offer substantially better performance than state of the art approaches. We obtain a number of useful analytic bounds that help characterise design trade-offs and our analysis highlights that the use of prediction plays a key role in achieving good performance in the presence of significant feedback delay. Our approach readily generalises to networks of paths and we illustrate this by application to multipath trans port scheduler design.This work has been supported by the Spanish Government (Ministerio de Economía y Competitividad, Fondo Europeo de Desarrollo Regional, FEDER) by means of the project ADVICE (TEC2015-71329-C2-1-R)

Nuevos modelos preclínicos en insuficiencia cardiaca: caracterización con técnicas de imagen avanzada y aplicación en nuevas terapias

Tesis doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Medicina, Departamento de Bioquímica. Fecha de lectura: 30-05-2017La insuficiencia cardíaca crónica (IC) se caracteriza por una alta prevalencia en los países occidentales, un impacto dramático en la calidad de vida del paciente y su capacidad funcional, y una enorme carga económica para los sistemas de salud. En la IC crónica, la transformación de los nuevos descubrimientos en investigación básica en mejoras en el cuidado de los pacientes es una prioridad, y se basa en una validación preclínica de nuevos conceptos diagnósticos y terapéuticos. Se han desarrollado modelos animales que recapitulan la IC en el laboratorio. Sin embargo, al igual que en otras enfermedades crónicas, el modelado de IC es un desafío debido a la heterogeneidad fisiopatológica. Los modelos de IC en animales grandes son costosos y técnicamente complejos, pero proporcionan una oportunidad única para evaluar nuevos conceptos y terapias de imagen utilizando herramientas clínicamente relevantes. Aunque los intentos de reproducir el cuadro clínico completo junto con anomalías hemodinámicas y estructurales graves de la IC crónica no han tenido éxito, la recapitulación de fenotipos específicos puede ser factible y clínicamente relevante. Este documento incluye un trabajo de Tesis doctoral centrado en la creación y caracterización de modelos animales grandes sobre características clave de la IC: 1) hipertensión pulmonar crónica y remodelado ventricular derecha; 2) remodelado ventricular izquierdo de causa isquémica y por sobrecarga de presión. Finalmente, se evalúan nuevas estrategias de terapia génica en la IC ventricular derecha asociada a hipertensión pulmonar crónica en el contexto preclínico. En general, este trabajo contribuye con nuevos hallazgos en investigación preclínica sobre terapias innovadoras para una mejor atención al paciente.Summary Chronic heart failure (HF) is characterized by a high prevalence in the aging western countries, dramatic impact in the patient quality of life and functional performance, and overwhelming economic burden for health systems. In chronic HF, translation of basic research knowledge into innovative patient care is a priority, and relies on the preclinical testing and validation of new diagnostic and therapeutic concepts. Animal models have been developed that recapitulate HF in the laboratory setting. However, as in other chronic diseases, modeling of HF is challenging due to the heterogeneous and complex pathophysiology. Models of HF in large animals are costly and technically complex, but provide a unique opportunity to evaluate novel imaging concepts and therapies using clinically relevant tools, and therefore accelerate the potential translation. While attempts to reproduce the full clinical picture along with severe hemodynamic and structural abnormalities of chronic HF have been unsuccessful, recapitulation of specific phenotypes may be feasible and clinically relevant. This document summarizes a PhD Thesis compendium focused on the creation and characterization of large animal models of key HF features: 1) chronic pulmonary hypertension and right ventricular remodeling, 2) ischemic and pressure overload left ventricular remodeling. Finally, novel strategies of gene therapy in chronic PH-associated right ventricular heart failure are evaluated in the preclinical setting. Overall, this work contributes with novel findings in a challenging field of preclinical research in the search of innovative therapies for better patient care

Estudio de inestabilidad inicial de paneles con el elmento BST

Peer Reviewe