New bounds on RAKE structures for DS-CDMA over frequency-selective Rayleigh fading channels

An upper bound is derived for the probability of error in an asynchronous binary direct-sequence spread-spectrum multiple-access communications system operating over frequency selective Rayleigh fading channels. A coherent RAKE receiver with predetection selective diversity combining is considered. The performance of a multipath-combining receiver is determined for the case of multiple interfering transmitters. Furthermore, the performance of the system is determined in terms of parameters of the signature sequences. These parameters can be used as guides in selecting sequences for the system. The bounds agree with the exponential portion of a normal distribution in which the interfering interference components subtract from the signal amplitude. The results obtained are verified by simulation.Peer ReviewedPostprint (published version

Desarrollo de las habilidades de escritura y trabajo colaborativo utilizando herramientas de la nube

La escritura, individual o colectiva, es una habilidad esencial que todos los graduados deben adquirir. Los ingenieros, por ejemplo, invierten entre un 20 y 40% de su tiempo escribiendo y este número crece con la responsabilidad del cargo que ocupen. Muchos de estos documentos se escriben en la actualidad colaborativamente, por ello, las universidades deben capacitar a sus alumnos en esta habilidad. Este artículo describe una actividad de escritura colaborativa desarrollada en la Universidad de Cantabria (UC), ofrece pautas para su desarrollo e indica las soluciones adoptadas para minimizar los problemas que inevitablemente surgen. Asimismo analiza los puntos fuertes y débiles de la experiencia.SUMMARY -- The writing, individual or collective, is an essential skill that all graduates should acquire. Engineers, for example, spend between 20 and 40% of his time writing and this number grows with the responsibility of the position they occupy. Currently, many of these documents are written collaboratively, therefore universities must train their students in this skill. This article describes a collaborative writing activity developed at the University of Cantabria (UC), offers guidelines for its development and indicates the solutions adopted to minimize the problems that inevitably arise. It also analyzes the strengths and weaknesses of this experience

Investigación educativa, políticas públicas y práctica docente: triángulo de geometría desconocida

El documento se encuentra organizado en cinco partes. En la primera se exponen los argumentos sobre la relación entre investigación educacional y su uso para la toma de decisiones. La segunda parte plantea el tema de las relaciones entre la investigación educacional, la práctica docente y las políticas públicas. La tercera parte es una reflexión sobre la relación entre investigación, práctica docente y políticas desde la perspectiva de la investigación educacional. En el cuarto apartado señala cuestiones relativas a la divulgación (trans-misión) de la investigación educacional a diferentes audiencias. En la última parte el autor concluye sobre el tema

Contribution of elastin to cardiovascular development in zebrafish

Elastin is the main structural protein of elastic fibers that allows tissues in vertebrates to extend and recoil. Heterozygous loss of function mutations in the elastin gene (ELN) can cause supravalvular aortic stenosis (SVAS), a rare obstructive cardiovascular disease typically characterized by a narrowing of the ascending aorta. The association of SVAS with hypertension, valvular defects and other congenital heart defects (CHDs) is of broader public health significance. The main goal of this research is to generate and characterize a set of SVAS-like mutant zebrafish lines. Zebrafish have two elastin genes, elna and elnb. First, I investigated the genetic and transcript diversity of zebrafish elastins by sequencing 46 and 44 overlapping cDNA clones from elna and elnb, respectively. I uncovered substantial variation in from both genes with a total of 79 single nucleotide variants (SNVs) in elna and 89 in elnb. In addition, there were numerous in-del variants and alternative splicing events. To assess the role of elna in zebrafish development, a line of elna homozygous mutants was established. The mutation (elnasa12235 c.264T>A, p.Tyr88*) induces nonsense-mediated decay in a developmentally regulated fashion with close to complete elimination of the mutant transcript starting at 3 days post-fertilization. Phenotypic examination of mutant embryos displayed reduced blood flow, regurgitation, valve and heart looping abnormalities. Regurgitation and valve irregularities was also observed in a mutant adult male. Histological examination of the hearts in adult elna mutant fish showed thinning and loss of the elastic cartilage-like morphology in bulboventricular valves. Further work with larger numbers of fish needs to be done, to obtain reliable estimates of the frequency and possible sex specificity, and clutch-to-clutch variability of valve and other cardiovascular defects in elna mutants. In conclusion, my studies show extensive sequence variation in elna and elnb. Mutants of elna have displayed promise to help explain cardiovascular development and detrimental effects of elastin mutations in humans with SVAS especially with respect to cardiac valve abnormalities

Estudio sobre la eficiencia de un sistema de propulsión diesel-eléctrico en embarcaciones de recreo

Aquest projecte es un estudi de l’eficiència d’un sistema de propulsió Diesel-Elèctrica en una embarcació d’esbarjo, tipus trawler, de 17 metres d’eslora, 30 tones de desplaçament i 1000 c.v. de potència. En aquest estudi es vol trobar l’estalvi de combustible que suposa substituir la transmissió mecànica amb una transmissió elèctrica i quina configuració ofereix major rendiment. Finalment, es farà una estimació sobre el termini d’amortització d’aquesta inversió per a valorar la seva viabilitat econòmica

A Differentiable Generative Adversarial Network for Open Domain Dialogue

Paper presented at the IWSDS 2019: International Workshop on Spoken Dialogue Systems Technology, Siracusa, Italy, April 24-26, 2019This work presents a novel methodology to train open domain neural dialogue systems within the framework of Generative Adversarial Networks with gradient-based optimization methods. We avoid the non-differentiability related to text-generating networks approximating the word vector corresponding to each generated token via a top-k softmax. We show that a weighted average of the word vectors of the most probable tokens computed from the probabilities resulting of the top-k softmax leads to a good approximation of the word vector of the generated token. Finally we demonstrate through a human evaluation process that training a neural dialogue system via adversarial learning with this method successfully discourages it from producing generic responses. Instead it tends to produce more informative and variate ones.This work has been partially funded by the Basque Government under grant PRE_2017_1_0357, by the University of the Basque Country UPV/EHU under grant PIF17/310, and by the H2020 RIA EMPATHIC (Grant N: 769872)