Investigation of the paht loss propagation for V2V communications in the opposite direction

[EN] In this work, we investigate the path loss propagation of the vehicular-to-vehicular (V2V) channel when the vehicles are driving in the opposite direction. The investigation is based on narrowband channel measurements at 700 MHz and 5.9 GHz carried out in different environments under real road traffic conditions, i.e., rural, highway, suburban and urban environments. The results show that there is a path loss offset between the forward and reverse directions, which is related to the environment. Also, we provide mean values of the path loss propagation exponent showing that are higher than the values derived when the vehicles are driving in the same direction. These results should be considered for a proper simulation and design of the future V2V communications systems.This work was supported in part by the Spanish Ministerio de Economía y Competitividad under Project TEC2013-47360-C3-3-P, and the Departamento Administrativo de Ciencia, Tecnología e Innovacion COLCIENCIAS de Colombia.Rubio Arjona, L.; Rodrigo Peñarrocha, VM.; Reig, J.; Fernández González, HA. (2016). Investigation of the paht loss propagation for V2V communications in the opposite direction. IEEE. 1685-1686. https://doi.org/10.1109/APS.2016.76965491685168

Path Loss Characterization Vehicular-to-Infrastructure Communications at 700 MHz and 5.9 GHz in Urban Environments

[EN] In this work, we perform a path loss characterization of the vehicular-to-infrastructure (V2I) channel in an urban environment based on a log-distance path loss propagation model. The model parameters have been derived from channel measurements at 700 MHz and 5.9 GHz. The correlation between the path loss exponent and the height of the antenna used in the infrastructure side is investigated. The measurements have been collected in an urban area of Valencia, Spain, under real road traffic conditions.This work was supported in part by the Spanish Ministerio de Economia y Competitividad under Project TEC2013-47360-C3-3-P, and the Departamento Administrativo de Ciencia, Tecnologia e Innovacion COLCIENCIAS de Colombia.Rubio Arjona, L.; Fernández González, HA.; Rodrigo Peñarrocha, VM.; Reig, J. (2015). Path Loss Characterization Vehicular-to-Infrastructure Communications at 700 MHz and 5.9 GHz in Urban Environments. IEEE Antennas and Propagation Society. 93-94. https://doi.org/10.1109/APS.2015.7304432939

Path loss characterization for vehicular communications at 700 MHz and 5.9 GHz under LOS and NLOS conditions

In this letter, we present a path loss characterization of the vehicular-to-vehicular (V2V) propagation channel. We have assumed a path loss model suitable for vehicular ad hoc networks (VANETs) simulators. We have investigated the value of the model parameters, categorizing in line-of-sight (LOS) and non-LOS (NLOS) paths. The model parameters have been derived from extensive narrowband channel measurements at 700 MHz and 5.9 GHz. The measurements have been collected in typical expected V2V communications scenarios, i.e., urban, suburban, rural, and highway, for different road traffic densities, speeds, and driven conditions. The results reported here can be used to simulate and design the future vehicular networks.Fernández González, HA.; Rubio Arjona, L.; Rodrigo Peñarrocha, VM.; Reig, J. (2014). Path loss characterization for vehicular communications at 700 MHz and 5.9 GHz under LOS and NLOS conditions. IEEE Antennas and Wireless Propagation Letters. 13:931-934. doi:10.1109/LAWP.2014.2322261S9319341

Analysis of Small-Scale Fading Distributions in Vehicle-to-Vehicle Communications

[EN] This work analyzes the characteristics of the small-scale fading distribution in vehicle-to-vehicle (V2V) channels. The analysis is based on a narrowband channelmeasurements campaign at 5.9GHz designed specifically for that purpose.Themeasurements were carried out in highway and urban environments around the city of Valencia, Spain.Theexperimental distribution of the small-scale fading is compared to several analytical distributions traditionally used to model the fast fading in wireless communications, such as Rayleigh, Nakagami-𝑚,Weibull, Rice, and 𝛼-𝜇 distributions. The parameters of the distributions are derived through statistical inference techniques and their goodness-of-fit is evaluated using the Kolmogorov-Smirnov (K-S) test. Our results show that the 𝛼-𝜇 distribution exhibits a better fit compared to the other distributions, making its use interesting to model the small-scale fading in V2V channels.This work has been funded in part by the Programa Estatal de Fomento de la Investigacion Cientifica y Tecnica de Excelencia del Ministerio de Economia y Competitividad, Spain, TEC2013-47360-C3-3-P, and the Departamento Administrativo de Ciencia, Tecnologia e Innovacion COLCIENCIAS en Colombia.Rodrigo Peñarrocha, VM.; Reig, J.; Rubio Arjona, L.; Fernández González, HA.; Loredo, S. (2016). Analysis of Small-Scale Fading Distributions in Vehicle-to-Vehicle Communications. Mobile Information Systems. 2016:1-7. https://doi.org/10.1155/2016/9584815S17201

Finerenona: completando el abordaje del paciente con enfermedad renal y diabetes

Chronic kidney disease; Fibrosis; InflammationEnfermedad renal crónica; Fibrosis; InflamaciónMalaltia renal crònica; Fibrosi; InflamacióDespite current treatments, which include renin angiotensin system blockers and SGLT2 inhibitors, the risk of progression of kidney disease among patients with diabetes and chronic kidney disease (CKD) remains unacceptably high. The pathogenesis of CKD in patients with diabetes is complex and includes hemodynamic and metabolic factors, as well as inflammation and fibrosis. Finerenone is a highly selective nonsteroidal mineralocorticoid antagonist that, in contrast to current therapies, may directly reduce inflammation and fibrosis, thus adding value in the management of these patients. In fact, finerenone decreases albuminuria and slows CKD progression in persons with diabetes. We now review the mechanisms of action of finerenone, the results of recent clinical trials, and the integration of the kidney and cardiovascular protection afforded by finerenone in the routine care of patients with diabetes and CKD.A pesar de los tratamientos actuales, que incluyen los inhibidores del sistema renina angiotensina y los inhibidores SGLT2, el riesgo de progresión de la enfermedad renal en los sujetos con diabetes y enfermedad renal crónica (ERC) continúa inaceptablemente alto. La patogenia de la ERC en el paciente con diabetes es compleja, e incluiría factores hemodinámicos, metabólicos, y de inflamación y fibrosis. La finerenona es un antagonista no esteroideo altamente selectivo del receptor mineralocorticoide que, a diferencia de los tratamientos actuales, podría disminuir directamente la inflamación y la fibrosis, aportando un valor añadido al abordaje de estos pacientes. De hecho, finerenona disminuye la albuminuria y enlentece la progresión de la ERC en personas con diabetes. La presente revisión aborda el mecanismo de acción de la finerenona, los resultados de ensayos clínicos recientes y la integración en práctica clínica de la nefroprotección y cardioprotección de la finerenona en el abordaje terapéutico integral del paciente diabético con ERC

The ecology of Roman trade. Reconstructing provincial connectivity with similarity measures

The creation of the Roman Empire promoted the connectivity of a vast area around the Mediterranean sea. Mobility and trade flourished over the Roman provinces as massive amounts of goods were shipped over thousands of kilometres through sea, rivers and road networks. Several works have explored these dynamics of interaction in specific case studies but there is still no consensus on the intensity of this connectivity beyond local trade. We argue here that the debate on the degree of large-scale connectivity across the empire is caused by a lack of appropriate methods and proxies of economic activity. The last years have seen an improvement on the availability of evidence as a growing amount of datasets is collected and published. However, data does not equal knowledge and the methods used to analyse this evidence have not advanced at the same pace. A new framework of connectivity analysis has been applied here to reveal the existence of distinctive trade routes through the provinces of the Western region of Rome. The amphora stamps collected over more than a thousand sites have been analysed using quantitative measures of similarity. The patterns that emerge from the analysis highlight the intense connectivity derived from factors such as the spatial closeness, presence of military units and the relevance of the Atlantic sea as a main shipping route

Experimental UWB propagation channel path loss and time-dispersion characterization in a laboratory environment

The knowledge of the propagation channel properties is an important issue for a successful design of ultrawideband (UWB) communication systems enabling high data rates in short-range applications. From an indoor measurement campaign carried out in a typical laboratory environment, this paper analyzes the path loss and time-dispersion properties of the UWB channel. Values of the path loss exponent are derived for the direct path and for a Rake receiver structure, examining the maximum multipath diversity gain when an all Rake (ARake) receiver is used. Also, the relationship between time-dispersion parameters and path loss is investigated. The UWB channel transfer function (CTF) was measured in the frequency domain over a channel bandwidth of 7.5GHz in accordance with the UWB frequency range (3.1 10.6GHz).The authors would like to thank the anonymous reviewer for his constructive suggestions and useful comments which have improved the final quality of the paper. This work has been funded in part by the Spanish Ministerio de Ciencia e Innovacion (TEC-2010-20841-C04-1).Rubio Arjona, L.; Reig, J.; Fernández González, HA.; Rodrigo Peñarrocha, VM. (2013). Experimental UWB propagation channel path loss and time-dispersion characterization in a laboratory environment. International Journal of Antennas and Propagation. 2013:1-7. https://doi.org/10.1155/2013/350167S17201

Caracterización de las pérdidas de propagación a 700 MHz y 5.9 GHz para comunicaciones vehiculares

[EN] This paper presents a path loss characterization of the vehicular-to-vehicular (V2V) propagation channel. We have proposed a linear relationship between the path loss and the logarithm of the transmitter-receiver separation distance. The parameters of the path loss model have been derived from extensive narrowband channel measurements at 700 MHz and 5.9 GHz. The measurements have been collected in typical expected V2V communications scenarios, i.e., urban, suburban, rural and highway, for different road traffic densities, speed and driven conditions. Values of the path loss exponent for a 95 % confidence interval are reported.Fernández González, HA.; Rodrigo Peñarrocha, VM.; Reig, J.; Rubio Arjona, L. (2014). Caracterización de las pérdidas de propagación a 700 MHz y 5.9 GHz para comunicaciones vehiculares. http://hdl.handle.net/10251/54433

Movilidad virtual en másteres a distancia en Europa y América Latina. Un camino por recorrer

La movilidad de los estudiantes en la educación superior es uno de los indicadores de la competitividad de las instituciones de ese nivel educativo y clave en su proceso de modernización. Las universidades que ofertan programas a distancia también están involucradas en estos procesos de movilidad de sus estudiantes, pero se encuentran con la realidad de que no todos pueden, o quieren, disfrutar de la oferta de movilidad, ni todos tienen ocasión de trasladarse a otra institución a cursar parte de sus estudios. Ante esta situación, el proyecto «NetActive» se propuso analizar la viabilidad de la oferta de programas de movilidad virtual para los estudiantes de programas a distancia en instituciones de Europa y América Latina. Para ello se analizó la información metodológica, organizativa y de contenido de 156 másteres a distancia pertenecientes a 16 países europeos y 34 latinoamericanos. Del análisis de los datos obtenidos la principal conclusión es que, si queremos avanzar en planteamientos de internacionalización y movilidad virtual, deberemos ofrecer posibilidades reales para su logro que, en definitiva, se trata de ofrecer másteres comparables y comprensibles, compatibles con otras ofertas académicas

Caracterización de las pérdidas de propagación en el canal de radio V2V para un escenario suburbano

El diseño de los futuros sistemas de comunicaciones vehiculares ha centrado la atención de la comunidad científica, los organismos de estandarización y fabricantes de vehículos durante estos últimos años como consecuenciade la introducción de los denominados sistemas de transporte inteligente y el gran potencial que tienen para mejorar las condiciones de seguridad en las carreteras, teniendo como propósito reducir el número de accidentes de tráfico y facilitar el flujo vehicular. Para diseñar, evaluar y optimizar las aplicaciones de los sistemas de transporte inteligente orientadas a la seguridad vehicular y basadas en sistemas de comunicaciones inalámbricos, es de vital importancia el conocimiento de las características del canal de propagación, en particular las pérdidas básicas de propagación. En este sentido, en el presente artículo se analizan las pérdidas de propagación en función de la distancia de separación entre los vehículos transmisor (Tx) y receptor (Rx). Con base en una campaña de medidas realizada a 700 MHz y 5,9 GHz en un entorno suburbano, de elevada densidad de tráfico rodado, se presentan resultados sobre el rango de variación del exponente de pérdidas y las características de desvanecimiento o variabilidad temporal de la señal recibida. Los resultados son comparados con otros estudios publicados en la literatura