765 research outputs found

    Diversity in mobile communications for blind detection of block-coded modulations

    Get PDF
    Spatial, temporal, and frequency diversity structures are analyzed to address the blind equalization problem in the presence of time-variant frequency selective channels. The aim of the paper is to present equalization schemes useful in front of fast changing channel responses. The best solution is a deterministic blind criterion that allows direct channel equalization and symbol detection. The main contribution of this paper is to present deterministic blind equalization schemes in CDMA systems (frequency diversity) to reduce the impact of the time-variant frequency selective channel.Peer ReviewedPostprint (published version

    El paper de la biblioteca en el suport a l'ensenyament telemàtic

    Get PDF

    Sedimentological study of Galicia coast: JI. Relation-ship between the distribution of grain size and the biogenic carbonate content in Pontevedra and Arousa beaches.

    Get PDF
    [Resumen] Dentro del estudio de los diferentes medios de depósitos sedimentarios de las Rías Gallegas, se presenta una distribución del contenido en carbonatos biogénicos así como las variaciones granulométricas del sector intermareal de las playas de Pontevedra y Arosa. Los puntos de muestreo fueron seleccionados en función del grado de exposición y condiciones de alta energía (zonas abiertas), y de baja energía (zonas interiores). Se levantaron perfiles topográficos en un total de 15 playas; en cada perfil se tomaron, como promedio, 3 muestras comprendidas entre los niveles de pleamar y bajamar, considerando puntos equivalentes para cada una de las playas. Los resultados obtenidos muestran en general una homogeneidad en cuanto a tamaño de grano, del orden de 2 a 0.25 mm, es decir, fracción media-gruesa. Es constante la presencia de los valores más finos hacia la parte alta de cada perfil. El contenido en carbonatos oscila entre un 20 y un 40 O/o para aquellas estaciones de muestreo situadas en zonas abiertas, mientras que en aquellas otras situadas hacia el interior su contenido no sobrepasa, en general, el 5 o/o. Estos valores pueden ser interpretados como resultado de la ubicación geográfica y su dinámica, actuando como indicador que puede ser extensible al resto del litoral gallego.[Abstract] A distribution of the biogenic carbonatic content and grain size for the intertidal zone of the beaches of the Ria de Pontevedra and Ria de Arosa is presented in this papero Sampling stations were chosen to reflect the different exposures and energy: high energy (open zones) and low energy (inner zones). Morphology of 15 beaches was determined by topographic profiling, with an average of 3 samples between high-water mark and low-water mark in each profile. This way, equivalent points in the different beaches can be compared. The results show a general grain-size homogneity with a predominance of the medium-coarse fraction, about 2-0.25 mm. A finer grain size is usually found in the upper part of each profile. The carbonatic content range is 20-40 O/o in open zones, whereas the content is less than 5 O/o in beaches towards the inner zones. This values are significant with respect to the geographical position of the beaches in each ria and the different dynamics. They are, then, an index that could be applied to the study of the whole Galician coast

    Geographic patterns of vertebrate diversity and identification of relevant areas for conservation in Europe

    Get PDF
    The ‘EU Council conclusions on biodiversity post–2010′ re–enforced Europe’s commitment to halt biodiversity loss by 2020. Identifying areas of high–value for biodiversity conservation is an important issue to meet this target. We investigated the geographic pattern of terrestrial vertebrate diversity status in Europe by assessing the species richness, rarity, vulnerability (according to IUCN criteria), and a combined index of the three former for the amphibians, reptiles, bird and mammals of this region. We also correlated the value of all indices with climate and human influence variables. Overall, clear geographic gradients of species diversity were found. The combined biodiversity index indicated that high–value biodiversity areas were mostly located in the Mediterranean basin and the highest vulnerability was found in the Iberian peninsula for most taxa. Across all indexes, the proportion of variance explained by climate and human influence factors was moderate to low. The results obtained in this study have the potential to provide valuable support for nature conservation policies in Europe and, consequently, might contribute to mitigate biodiversity decline in this region

    Effect of environmental conditions and phenology in the dispersal of secondary Erysiphe necator conidia in a vineyard

    Get PDF
    An integrated powdery mildew management strategy to identify the principal moments of secondary Erysiphe necator conidia dispersal in a vineyard based on aerobiological, phenological and meteorological data was developed. An adaptation of the physiological P-days model was conducted to obtain a descriptive equation for the prediction of the advantageous meteorological conditions for Erysiphe necator conidia dispersal in the vineyards of the Ribeiro Designation of Origin area. Moreover, a regression model was developed to predict the conidia concentration as a function of the weather and aerobiological variables with the highest influence on airborne E. necator spores. Additionally, phenological observations were conducted during the vegetative cycle of Vitis vinifera, with the aim to identify the most susceptible phenological stages to powdery mildew infection by relating them with the detected atmospheric spore concentrations. The study was carried out from 2008 to 2018 in an experimental vineyard. The E. necator spores were trapped using a Lanzoni VPPS-2000 sampler and the phenological observations were conducted following the BBCH standardized scale. The highest total fungal spore amount per season in the atmosphere of the vineyard was detected in 2013 with 4828 spores m-3, while the lowest amount was recorded in 2009 with 883 spores m-3. In general, the highest daily airborne spore concentrations were detected during the Flowering (stage 6) or in the previous and next stages, whereas the maximum total spore amount by stage was recorded during Development of Fruits (stage 7). The proposed threshold of P-days for potential secondary infections in the Ribeiro D.O. ranges from 120 to 160 P-days. The combination of aerobiological, phenological and meteorological data provides us a useful tool for the knowledge of the Erysiphe necator conidia dispersal behaviour bringing agricultural practices closer to a sustainable system

    Variables in Globular Cluster NGC 5024

    Full text link
    We present the results of a commissioning campaign to observe Galactic globular clusters for the search of microlensing events. The central 10' X 10' region of the globular cluster NGC 5024 was monitored using the 2-m Himalayan Chandra Telescope in R-band for a period of about 8 hours on 24 March 2010. Light curves were obtained for nearly 10,000 stars, using a modified Difference Image Analysis (DIA) technique. We identified all known variables within our field of view and revised periods and status of some previously reported short-period variables. We report about eighty new variable sources and present their equatorial coordinates, periods, light curves and possible types. Out of these, 16 are SX Phe stars, 10 are W UMa-type stars, 14 are probable RR Lyrae stars and 2 are detached eclipsing binaries. Nine of the newly discovered SX Phe stars and two eclipsing binaries belong to the Blue Straggler Star (BSS) population.Comment: 29 pages, 22 figures, replaced with rewritten data reduction par

    Well-being of suckling calves under two different rearing systems: case study in the central milk basin of Argentina

    Get PDF
    En el presente trabajo se llevo a cabo un estudio de caso con enfoque cuantitativo. El objetivo de este estudio fue evaluar el bienestar en teneros lechales durante la época invernal bajo dos diferentes sistemas de crianza, que se utilizan en la zona. Los terneros, se alojaron en dos sistemas: en estaca los machos y en jaula las hembras. Los animales recibieron dos tomas diarias de leche (4 l/día), balanceado iniciador y agua ad libitum. Se registraron pesos iníciales y finales. La ganancia de peso se analizó mediante técnicas estadísticas descriptivas. Se tomaron muestra de saliva para determinar cortisol (CS) en cuatro momentos del día. Los datos fueron analizados para detectar variaciones horarias. El CS no mostró fluctuaciones diarias. Durante quince días y día por medio, se registraron las conductas: parado, echado, comiendo y otras. La metodología de observación y registro utilizada fue el muestreo de barrido a intervalos regulares. Los datos de analizaron con la prueba del c2. El efecto tratamiento fue significativo sobre el comportamiento (p<0,01). Los animales de los dos sistemas gastaron el 50% del tiempo en la conducta de reposo.Well-being of suckling calves under two different rearing systems. Case study in the central milk basin of Argentina. In this paper we conducted a case study with quantitative approach. The aim of this study was to assess welfare in suckling calves during the winter season under two different rearing systems, which are used in the area. Calves were housed in two systems: a stake in males and females cage. All animals received 4 L milk per day, in two servings. Water and a commercial starter were offered ad libitum. Initial and final weights were recorded, weight gain was analyzed using descriptive statistical techniques. Saliva samples were taken at four times over the day, to analyze saliva cortisol (SC). Data were analyzed for time variations. Neither daily fluctuations in SC concentrations nor system effects were detected in SC concentrations. Different behaviors: standing, lying, eating and "others" were observed every other day over a fortnight. Scan sampling at regular intervals was utilized. Data were analyzed by a c2 test. Systems effects were observed on behavioral conducts (p<0.01). Animals in both systems spent 50% of their time lying.Fil: Leva, Paula Edit. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García, M. S.. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Toffoli Arnaudo, Guillermo Daniel. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Rodríguez, A. G.. Universidad Nacional del Litoral. Facultad de Ciencias Agrarias; ArgentinaFil: Rey, Florencia. Universidad Nacional del Litoral. Facultad de Ciencias Veterinarias; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

    LA VIOLENCIA ESCOLAR EN LA EDUCACIÓN PRIMARIA DE MANAGUA: COMPRENDER EL CONTEXTO PARA ABORDAR LA REALIDAD

    Get PDF
    El artículo que presentamos pretende ofrecer un acercamiento a la realidad interrelacional presente en los y las escolares de Nicaragua, un país pobre donde se registran altos nivel de violencia. Este estudio, que cuenta con una muestra de 3.042 estudiantes, analiza la relación que existe entre los roles que participan en los fenómenos de acoso y maltrato entre iguales (agresores, víctimas, agresores victimizados y espectadores) y las formas de manifestación de este tipo de violencia interpersonal. Los resultados parecen indicar que las convenciones sociales creadas dentro del grupo de iguales constituyen la materia de su aprendizaje social, ya que existe un destacado porcentaje de niños y niñas que a la vez de manifestar conductas violentas también son víctimas de abusos de poder.This article is aimed to offer an approach of the inter-relational reality presents in pupils from Nicaragua, a poor country where there are high levels of violence. This study, with a sample of 3042 students, examines the relationship between the roles involved in the phenomenon of harassment and abuse among peers (aggressors, victims, victimisedaggressors and spectators) and the forms of manifestation of this type of interpersonal violence. Results suggest that social conventions created within the peer group are the subject of their social learning, as there is a high percentage of boys and girls that, at the same time they manifest violent behaviours, are also victims of abuse of power
    corecore